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Age changes in the human frontozygomatic suture
Abstract
The frontozygomatic suture of human cadaver material was examined by a combination of histologic, radiographic, and gross tecniques to determine the aging changes in the suture and the approximate age at which sutural fusion occurs. The sample consisted of sixty-One specimens of human beings ranging in age from 20 to 95 years. Observations were made on specimens at age intervals of 5 years. Since the frontozygomatic suture is bilateral, one suture from each specimens was used for radiographic and gross examination for synostosis, and the opposite side was subjected to histologic analysis. The findings of this study have lead to the following conclusions: 1. The human frontozygomatic suture undergoes synostosis during the eigth decade of life, but does not completely fuse by the age of 95 years. 2. Synostosis is a progressive process which commences as small areas of bony union that occur initially within the internal portion of the suture and then progresses to the orbital perisosteal surface. Bony union is not found at or near the facial periosteal surface. 3. The bony surfaces of the frontozygomatic suture become increasingly irregular with advancing age as a result of the formation of projections or interifitations=
... They may close by fusion of the sutural bone fronts in sutures, or by the replacement of cartilage by endochondral bone in synchondroses. These articulations have been thoroughly investigated for the understanding of craniosynostosis in human infants (the premature fusion of the bones of the skull; Kokich, 1986;Opperman et al. 2005) and for applications in orthodontology (Kokich, 1976). They have also been described anatomically and in regards to skull biomechanics in various vertebrate clades (Herring, 1972;Herring & Mucci, 1991;Sun et al. 2004;Rayfield, 2005;Holliday & Witmer, 2008;Curtis et al. 2013). ...
... The way that sutures and synchondroses form and fuse has only been reported in mammals (Pritchard et al. 1956;Kokich, 1976;Persson et al. 1978;Herring, 2000;Opperman et al. 2005) and, unfortunately, very little is known about those structures in non-mammalian vertebrates at the microscopic scale, including in archosaurs. For this reason, the main goal of this study was to document sutural and synchondroseal microstructure in non-avian dinosaurs and their extant phylogenetic bracket (Witmer, 1995). ...
... Despite this, the relationship between closure (seen morphologically), fusion (seen histologically) and the overall growth of the skull remains ambiguous and is undoubtedly not simple. Studies concerning the precise microscopic structure of cranio-facial sutures through ontogeny remain rare and exclusively concern humans (Kokich, 1976;Persson & Thilander, 1977) and other mammals (mostly rats and rabbits; Pritchard et al. 1956;Moss, 1958;Persson, 1973). ...
Sutures and synchondroses, the fibrous and cartilaginous articulations found in the skulls of vertebrates, have been studied for many biological applications at the morphological scale. However, little is known about these articulations at the microscopic scale in non-mammalian vertebrates, including extant archosaurs (birds and crocodilians). The major goals of this paper were to: (i) document the microstructure of some sutures and synchondroses through ontogeny in archosaurs; (ii) compare these microstructures with previously published sutural histology (i.e. that of mammals); and (iii) document how these articulations with different morphological degrees of closure (open or obliterated) appear histologically. This was performed with histological analyses of skulls of emus, American alligators, a fossil crocodilian and ornithischian dinosaurs (hadrosaurids, pachycephalosaurids and ceratopsids). Emus and mammals possess a sutural periosteum until sutural fusion, but it disappears rapidly during ontogeny in American alligators. This study identified seven types of sutural mineralized tissues in extant and extinct archosaurs and grouped them into four categories: periosteal tissues; acellular tissues; fibrous tissues; and intratendinous tissues. Due to the presence of a periosteum in their sutures, emus and mammals possess periosteal tissues at their sutural borders. The mineralized sutural tissues of crocodilians and ornithischian dinosaurs are more variable and can also develop via a form of necrosis for acellular tissues and metaplasia for fibrous and intratendinous tissues. It was hypothesized that non-avian dinosaurs, like the American alligator, lacked a sutural periosteum and that their primary mode of ossification involved the direct mineralization of craniofacial sutures (instead of intramembranous ossification found in mammals and birds). However, we keep in mind that a bird-like sutural microstructure might have arisen within non-avian saurichians. While synchondroseal histology is relatively similar in archosaurs and mammals, the microstructural differences between the sutures of these two clades are undeniable. Moreover, the current results suggest that the degree of sutural closure can only accurately be known via microstructural analyses. This study sheds light on the microstructure and growth of archosaurian sutures and synchondroses, and reveals a unique, undocumented histological diversity in non-avian dinosaur skulls.
... Other factors, however, may better explain or predict measured craniosacral rates. For example, Burch, Cohn, and Neumann (21) and Christ et al (22) described spontaneous rhythmic volume changes in the digits and limbs of subjects that occured at rates similar to those described by Upledger for the craniosacral rhythm. These rhythmic volume fluctuations were independent of respiratory and cardiac rates and were thought to be related to autonomic vasomotor function. ...
... His proposal that viable sutures may allow slight motion is therefore limited to this population alone and does not shed much light on sutures in adults. Also, there is evidence to suggest that the five cellular layers described by Pritchard may not even persist into adulthood; again reflecting the limitations of drawing conclusions from this study (22). ...
... Sutural fusion makes malrelationships less amenable to treatment and so knowing when these sutures fuse is essential to the timing and placement of these appliances. In a study that we believe sets a standard of excellence in suture closure research, V. G. Kokich (22), investigated a method for documenting age-related changes in a craniofacial suture. Using radiographic and histological techniques he clearly documented age related changes in the frontozygomatic suture. ...
... Introduction [9][10][11] Therefore, in adults, skeletal orthopedic expansion is necessary to prevent these issues and to correct transverse maxillary deficiency. [12][13][14] Surgically assisted RPE (SARPE) is the conventional treatment of choice to correct transverse maxillary deficiency in adults. ...
... [12][13][14] Surgically assisted RPE (SARPE) is the conventional treatment of choice to correct transverse maxillary deficiency in adults. [9][10][11]15 However, SARPE is an invasive process that has been found to result in lateral rotation of the two maxillary halves with minimal horizontal translation. [9][10][11] In addition, SARPE may be detrimental to the periodontium and has been shown to result in a large amount of relapse during the postretention period. ...
... [9][10][11]15 However, SARPE is an invasive process that has been found to result in lateral rotation of the two maxillary halves with minimal horizontal translation. [9][10][11] In addition, SARPE may be detrimental to the periodontium and has been shown to result in a large amount of relapse during the postretention period. 16,17 Recently, bone-borne palatal expanders have been reported in several case presentations to have the capability to correct transverse maxillary deficiency in adults making it a potential alternative to SARPE. ...
Introduction
Bone-borne palatal expansion relies on mini-implant stability for successful orthopedic expansion. The large magnitude of applied force experienced by mini-implants during bone-borne expansion may lead to high failure rates. Use of bicortical mini-implant anchorage rather than monocortical anchorage may improve mini-implant stability. The aims of this study were to analyze and compare the effects of bicortical and monocortical anchorages on stress distribution and displacement during bone-borne palatal expansion using finite element analysis.
Methods
Two skull models were constructed to represent expansion before and after midpalatal suture opening. Three clinical situations with varying mini-implant insertion depths were studied in each skull model: monocortical, 1-mm bicortical, and 2.5-mm bicortical. Finite element analysis simulations were performed for each clinical situation in both skull models. Von Mises stress distribution and transverse displacement were evaluated for all models.
Results
Peri-implant stress was greater in the monocortical anchorage model compared with both bicortical anchorage models. In addition, transverse displacement was greater and more parallel in the coronal plane for both bicortical models compared with the monocortical model. Minimal differences were observed between the 1-mm and the 2.5-mm bicortical models for both peri-implant stress and transverse displacement.
Conclusions
Bicortical mini-implant anchorage results in improved mini-implant stability, decreased mini-implant deformation and fracture, more parallel expansion in the coronal plane, and increased expansion during bone-borne palatal expansion. However, the depth of bicortical mini-implant anchorage was not significant.
... T he cranial sutures, which approximate each other during development, are the fibrous tissues combining the skull bones. 1 These sutures are formed during the embryonic development at the contact lines between membranous bones of craniofacial skeleton. 1 The cranial sutures are simple and straight in young humas. 2 Aging process leads cranial sutures to enormous change, [2][3][4] and then they become more complex and bring out interdigitations [2][3][4][5][6][7] through the growth and resorption process of cranial bones. 3,5 The genetic and environmental factors affect the morphology of the skull, and it is also supposed that function of muscles affects the bone shape and size. ...
... 24 Besides, the intrinsic factors, extrinsic, or environmental factors (such as tensile forces, growing brain, and the effect of active muscles) are more likely to affect the features of cranial sutures. 1,2,6,[9][10][11][12][13]25,26 In some patients, the complete closure obscures any signs of the cranial suture. Patency or obliteration of sutures may be determined by the presence or lack of physical forces acting on the skull. ...
Objective:
To investigate the degree of fusion (patency) among cranial sutures in human dry skulls in the Anatolia.
Methods:
One-hundred fifty-eight human dry skulls that were accepted as adults according to the teeth eruption were macroscopically examined and photographed with Canon 400B (55 mm objective). The grades of fusion of coronal, sagittal, and lambdoid were quantitatively analyzed by using the modified grading scale. According to the extent of patency, the sutures were graded as grade-0 (open), grade-1 (fused but not obliterated), grade-2 (50%< obliterated), grade-3 (50% > obliterated), and grade-4 (100% obliterated). The authors determined and compared the rate for each grade of sutural patency on coronal, sagittal, and lambdoid sutures.
Results:
The cranial sutures of 4 cranii (4/158; 2.53%) had grade-4 fusion, whereas there were no any cranii with sutures of grade-0 fusion. The number of each grade of fusion among cranial sutures of 158 skulls, in descending order, was as follows: 171 (grade-3), 145 (grade-1), 133 (grade-2), and 25 (grade-4). The grade-4 fusion was significantly less observed than the others. The grade-1 and grade-4 fusion of lambdoid sutures were established as the most (66/41.8%) and least (5/3.2%) common fusions among cranial sutures, respectively. The frequencies of each grade of fusion for each cranial suture were determined in a descending order: coronal (grade-3 > 2 > 1 > 4), sagittal (grade-3 > 2 > 1 > 4), and lambdoid sutures (grade-1 > 3 > 2 > 4). The frequency of grade-1 fusion of lambdoid suture (66/41.8%) was significantly different when compared with coronal (39/24.7%) and sagittal sutures (40/25.3%), respectively.
Conclusion:
The grades of fusion (or sutural patency) vary among cranial sutures.
... Unlike calvarial sutures, which are known to fuse at around the 20s, the facial sutures have been shown to remain patent after cessation of active growth. 12 This indicates the possibility of successful orthopedic expansion even in skeletally mature and old patients. The following case describes the treatment of a 60-year old patient who showed crowding accompanied by the risk of gingival recession and alveolar bone loss via nonsurgical orthopedic expansion. ...
... [8][9][10][11] On the other hand, the regulatory mechanism behind the fusion of facial sutures differs from that of calvarial sutures. 12,26 According to a previous study, cranial sutures are obliterated in the absence of dura mater. 27 The lack of such biochemical modulation by dura mater in the facial sutures may enable nonsurgical expansion even in elderly patients with interdigitated sutures, as long as they are not fused at the histologic level. ...
Maxillary transverse deficiency often manifests as a posterior crossbite or edge-to-edge bite and anterior crowding. However, arbitrary arch expansion in mature patients has been considered to be challenging due to the possible periodontal adverse effects such as alveolar bone dehiscence and gingival recession. To overcome these limitations, nonsurgical maxillary expansion of the basal bone has been demonstrated in young adults. However, the age range for successful orthopedic expansion has remained a topic of debate, possibly due to the underlying individual variations in suture maturity. This case report illustrates nonsurgical, miniscrew-assisted rapid palatal expansion (MARPE) in a 60-year-old patient with maxillary transverse deficiency accompanied by anterior and posterior crossbites, crowding, and gingival recession. The use of MARPE allowed relief of crowding and correction of the crossbite without causing significant periodontal adverse effects.
... More recently, Rafferty and Herring (1999) found CB in the nasofrontal suture of 4 to 6 month-old miniature pigs. These studies have shown that during early ontogenesis, it is CB that forms the sutural borders, not bone (contra Kokich, 1976;Pritchard et al., 1956). ...
... Indeed, sutures are often mentioned in paleontological studies because they are used for maturity assessment (e.g., Bakker and Williams, 1988;Longrich and Field, 2012;Sereno et al., 2009). However very little is known about the sutures of dinosaurs (or even extant archosaurs) from a histological perspective and only a few living mammalian species have been sectioned (i.e., some humans, Kokich, 1976;Koskinen et al., 1976;Latham, 1971;Miroue and Rosenberg, 1975;Opperman, 2000;Persson and Thilander, 1977;Sitsen, 1933; and some rats and rabbits, Moss, 1958;Persson, 1973;Persson et al., 1978;Persson and Roy, 1979;Pritchard et al., 1956). For future paleontological studies, it is important to document the osteohistology of sutures in order to understand their morphology and their (potential) relationship to ontogeny. ...
In histology textbooks, the vertebrate skeleton is represented as almost entirely made of bone and cartilage. This is a false dichotomy and in fact, a continuum of intermediate tissues between bone and cartilage exists. Chondroid bone ([CB] or chondroid tissue), one of the most well-known intermediate tissues, has been reported in mammals, birds and crocodilians. It accommodates (1) rapid growth of the skull and (2) the development of craniofacial sutures. Since CB is present in the extant phylogenetic bracket of the Dinosauria, we hypothesized that it was also present in non-avian dinosaurs. By means of paleohistological examination and microradiography, we report for the first time the presence of CB in non-avian dinosaur embryos and nestlings (Ornithischia: Hadrosauridae). It was found in five locations: (1) scattered within the bone trabeculae of an embryonic surangular; (2) and (3) in the coronoid process and in the alveolar processes of an embryonic dentary; (4) in the mandibular symphyses of an embryonic and a post-hatching dentary; (5) at the fronto-postorbital suture of an embryo. In these areas, CB was present in large amounts, suggesting that it played an important role in the rapid growth of the hadrosaurian skull during embryonic development. Moreover, the CB present in the sutural borders of a Hypacrosaurus frontal suggests that it was also involved in sutural growth, as it has been reported to be in mammalian and avian sutures. This is the first step taken to document and understand dinosaurian sutures from a histological perspective and it sheds light on an old problem by reporting the presence of CB in an additional clade within the Vertebrata. It is parsimonious to propose that CB in the chick embryo, Gallus gallus, the American alligator, Alligator mississippiensis and the hadrosaurs of the present study are homologous and that CB arose once and was inherited from their common ancestor.
... Although cranial sutures form in the absence of muscle activity (Hirabayashi et al., 1989), a number of studies support Moss' hypothesis that the fine details of suture morphology are secondary responses to extrinsic forces, and incurred strain modes (Moss, 1957; Herring and Mucci, 1991; Anton et al., 1992; Rafferty and Herring, 1999; Byron et al., 2004; Markey et al., 2006; Markey and Marshall, 2007; Byron, 2009). In patent sutures, suture complexity and tissue structure changes over time and with a change in masticatory forces (Massler and Schour, 1951; Gross, 1961; Milch, 1966; Kokich, 1976; Miroue and Rosenberg, 1975; Saito et al., 2002; Mao, 2003; Byron et al., 2004; Wang et al., 2006b; Byron, 2009; Smith et al., 2010). The change in suture morphology before suture fusion (such as bony bridging, interdigitation, and beveling) is thus of particular interest within the context of the biomechanical environment. ...
... It is worth to noting that the diversity of sutural morphologies (in both surface and cross-sectional views) poses a challenge to the analysis of sutural biology and biomechanics (Herring, 1993; Herring and Mucci, 1991; Rafferty and Herring, 1999; Byron et al., 2004; Markey et al., 2006; Markey and Marshall, 2007; Byron, 2009; Wang et al., 2012). In patent sutures, suture complexity (ectocranial sinuosity) and tissue structure changes over time and with a change in masticatory forces (Massler and Schour, 1951; Gross, 1961; Milch, 1966; Kokich, 1976; Miroue and Rosenberg, 1975; Saito et al., 2002; Mao, 2003; Byron et al., 2004; Wang et al., 2006b; Byron, 2009; Smith et al., 2010). Other studies demonstrated that the suture interdigitation pattern is complex and diversified, and often disconnected from the ectocranial sinuosity pattern (Markey and Marshall, 2007). ...
Craniofacial sutures are bone growth fronts that respond and adapt to biomechanical environments. Little is known of the role sutures play in regulating the skull biomechanical environment during patency and fusion conditions, especially how delayed or premature suture fusion will impact skull biomechanics. Tgf-β3 has been shown to prevent or delay suture fusion over the short term in rat skulls, yet the long-term patency or its consequences in treated sutures is not known. It was therefore hypothesized that Tgf-β3 had a long-term impact to prevent suture fusion and thus alter the skull biomechanics. In this study, collagen gels containing 3 ng Tgf-β3 were surgically placed superficial to the posterior interfrontal suture (IFS) and deep to the periosteum in postnatal day 9 (P9) rats. At P9, P24, and P70, biting forces and strains over left parietal bone, posterior IFS, and sagittal suture were measured with masticatory muscles bilaterally stimulated, after which the rats were sacrificed and suture patency analyzed histologically. Results demonstrated that Tgf-β3 treated sutures showed less fusion over time than control groups, and strain patterns in the skulls of the Tgf-β3-treated group were different from that of the control group. Although bite force increased with age, no alterations in bite force were attributable to Tgf-β3 treatment. These findings suggest that the continued presence of patent sutures can affect strain patterns, perhaps when higher bite forces are present as in adult animals.
... More recently, Rafferty and Herring (1999) found CB in the nasofrontal suture of 4 to 6 month-old miniature pigs. These studies have shown that during early ontogenesis, it is CB that forms the sutural borders, not bone (contra Kokich, 1976;Pritchard et al., 1956). ...
... Indeed, sutures are often mentioned in paleontological studies because they are used for maturity assessment (e.g., Bakker and Williams, 1988;Longrich and Field, 2012;Sereno et al., 2009). However very little is known about the sutures of dinosaurs (or even extant archosaurs) from a histological perspective and only a few living mammalian species have been sectioned (i.e., some humans, Kokich, 1976;Koskinen et al., 1976;Latham, 1971;Miroue and Rosenberg, 1975;Opperman, 2000;Persson and Thilander, 1977;Sitsen, 1933; and some rats and rabbits, Moss, 1958;Persson, 1973;Persson et al., 1978;Persson and Roy, 1979;Pritchard et al., 1956). For future paleontological studies, it is important to document the osteohistology of sutures in order to understand their morphology and their (potential) relationship to ontogeny. ...
... [4] Obliteration is a multifactorial phenomenon depending on age, genetic factors, tensile stresses, brain growth, tissue interactions, and biochemical signaling. [5][6][7] Therefore, age estimation using only suture obliteration is unreliable. [8] However, suture obliteration can be used with other cranial indicators to conclusively determine the age. ...
... It depends on age, genetic factors, tensile stresses, and tissue interactions. [5][6][7] The role of TGF-β in cranial suture fusion is now conclusively demonstrated in physiological mouse models. [11] The tensile forces of the muscles and ligaments attached near the suture delay the obliteration of the suture. ...
... La permeabilidad u obliteración de las suturas pueden ser atribuidas a la presencia o ausencia de fuerzas físicas (tensión muscular) en los distintos huesos del cráneo 16,17 . De ahí, que los numerosos músculos y ligamentos que se insertan en el hueso occipital y confi eren movilidad a la columna cervical pueden contribuir a que la sutura lambdoidea esté bajo más estrés y, por ello, sea más patente que la sutura sagital, al estar ésta sometida a menor cantidad de fuerzas 14 . ...
... La teoría de que las fuerzas externas mantienen la permeabilidad puede comprobarse por las características morfológicas de las suturas faciales, que son más serradas e interdigitadas que las suturas craneales y permanecen patentes durante períodos más largos 17,18 . Esta diferencia pue-de ser constatada al correlacionarla con los músculos faciales utilizados para hablar, masticar y en la expresión facial. ...
Objective
The technique of “alternative rocking of temporal bones” was used to assess the different degree of mobility in the temporal bones in several age groups. Our objectives are: correlating the examiner’s subjective assessment with the objectively quantifiable data of time and power required to obtain the maximum rotation of each of the temporal bones, and understanding the relationship between the age of the patients with the time and power parameters used.
... Of the specimens evaluated, all but one was less than one year old, therefore limiting the conclusions that could be drawn from the study in regard to CST and adult sutures. A second study often cited by proponents of CST as evidence that sutures do not completely fuse, was performed by Kokich (1976). This study demonstrated serial age changes from 20 to 95 years in the frontozygomatic suture. ...
Study Design: Quasi-experimental design. Objectives: To determine if physical manipulation of the cranial vault sutures will result in changes of the intracranial pressure (ICP) along with movement at the coronal suture. Background: Craniosacral therapy is used to treat conditions ranging from headache pain to developmental disabilities. However, the biological premise for this technique has been theorized but not substantiated in the literature. Methods: Thirteen adult New Zealand white rabbits (oryctolagus cuniculus) were anesthetized and microplates were attached on either side of the coronal suture. Epidural ICP measurements were made using a NeuroMonitor transducer. Distractive loads of 5, 10, 15, and 20 g (simulating a craniosacral frontal lift technique) were applied sequentially across the coronal suture. Baseline and distraction radiographs and ICP were obtained. One animal underwent additional distractive loads between 100 and 10 000 g. Plate separation was measured using a digital caliper from the radiographs. Two-way analysis of variance was used to assess significant differences in ICP and suture movement. Results: No significant differences were noted between baseline and distraction suture separation (F = 0.045; P.05) and between baseline and distraction ICP (F = 0.279; P.05) at any load. In the single animal that underwent additional distractive forces, movement across the coronal suture was not seen until the 500-g force, which produced 0.30 mm of separation but no corresponding ICP changes. Conclusion: Low loads of force, similar to those used clinically when performing a craniosacral frontal lift technique, resulted in no significant changes in coronal suture movement or ICP in rabbits. These results suggest that a different biological basis for craniosacral therapy should be explored.
... [1][2][3][4][5][6][7] Traditionally, surgically assisted RME has been the treatment of choice for adults to overcome their interdigitated midpalatal suture and decreased elasticity of bone, but this method produces only minimal horizontal translation and was mainly a lateral rotation of the 2 maxillary halves. [8][9][10] In addition, Byloff and Mossaz 11 demonstrated a large amount of relapse during the postretention period; however, other studies have shown mean relapse amounts of less than 1 mm. 12,13 Gauthier et al 14 reported radiographic changes that might have a detrimental clinical impact on the periodontium. ...
The aim of this study was to analyze stress distribution and displacement of the craniofacial structures resulting from bone-borne rapid maxillary expanders with and without surgical assistance using finite element analysis.
Five designs of rapid maxillary expanders were made: a tooth-borne hyrax expander (type A); a bone-borne expander (type B); and 3 bone-borne surgically assisted modalities: separation of the midpalatal suture (type C), added separation of the pterygomaxillary sutures (type D), and added LeFort I corticotomy (type E). The geometric nonlinear theory was applied to evaluate the Von Mises stress distribution and displacement.
The surgical types C, D, and E demonstrated more transverse movement than did the nonsurgical types A and B. The amounts of expansion were greater in the posterior teeth in types A and B, but in types C, D, and E, the amounts of expansion were greater in the anterior teeth. At the midpalatal suture, the nonsurgical types showed more anterior expansion than did the posterior region, and higher stresses than with the surgical types. Type B showed the highest stresses at the infraorbital margin, anterior and posterior nasal spines, maxillary tuberosity, and pterygoid plate and hamulus.
The 3 surgical models showed similar amounts of stress and displacement along the teeth, midpalatal sutures, and craniofacial sutures. Therefore, when using a bone-borne rapid maxillary expander in an adult, it is recommended to assist it with midpalatal suture separation, which requires minimal surgical intervention.
... Therefore, orthopedic expansion of the basal bone is crucial to avoid these effects and to establish proper posterior occlusion (Capelozza Filho et al., 1996; Chang et al., 1997; Garib et al., 2005; Koudstaal et al., 2009; Gurel et al., 2010; Baysal et al., 2011a). Conventionally, surgically assisted RME has been applied to overcome the decreased elasticity of bone and increased resistance of interdigitated mid-palatal suture in adults (Kokich, 1976; Harzer et al., 2006; Tausche et al., 2007). Nevertheless, surgically assisted RME has resulted mainly in a lateral rotation of the two maxillary halves with only minimal horizontal translation and associated with large amount of relapse during postretention period (Byloff and Mossaz, 2004). ...
The aim of this study was to analyze stress distribution and displacement of the maxilla and teeth according to different designs of bone-borne palatal expanders using micro-implants. A three-dimensional (3D) finite-element (FE) model of the craniofacial bones and maxillary teeth was obtained. Four designs of rapid maxillary expanders: one with micro-implants placed lateral to mid-palatal suture (type 1), the second at the palatal slope (type 2), the third as in type 1 with additional conventional Hyrax arms (type 3), and the fourth surgically assisted tooth-borne expander (type 4) were added to the FE models. Expanders were activated transversely for 0.25mm. Geometric nonlinear theory was applied to evaluate Von-Mises Stress distribution and displacement. All types exhibited downward displacement and demonstrated more horizontal movement in the posterior area. Type 3 showed the most transverse displacement. The rotational movement of dentoalveolar unit was larger in types 1 and 3, whereas it was relatively parallel in types 2 and 4. The stresses were concentrated around the micro-implants in types 1 and 3 only. Type 2 had the least stress concentrations around the anchorage and showed alveolar expansion without buccal inclination. It is recommended to apply temporary anchorage devices to the palatal slopes to support expanders for efficient treatment of maxillary transverse deficiency.
... Facial bones are surrounded by fibrous periosteal capsules that are fully established by the seventeenth week of gestation, whereas cranial bones develop in a preformed continuous fibrous membrane and only develop fibrous capsules after birth [71]. Unlike facial sutures, which close around the 7th–8th decades, cranial sutures close earlier in life [72]. Hence, for the purpose of this review we will focus exclusively on sutures of the cranial vault. ...
The cranial neural crest and the cranial mesoderm are the source of tissues from which the bone and cartilage of the skull, face and jaws are constructed. The development of the cranial mesoderm is not well studied, which is inconsistent with its importance in craniofacial morphogenesis as a source of precursor tissue of the chondrocranium, muscles, vasculature and connective tissues, mechanical support for tissue morphogenesis, and the signaling activity that mediate interactions with the cranial neural crest. Phenotypic analysis of conditional knockout mouse mutants, complemented by the transcriptome analysis of differentially enriched genes in the cranial mesoderm and cranial neural crest, have identified signaling pathways that may mediate cross-talk between the two tissues. In the cranial mesenchyme, Bmp4 is expressed in the mesoderm cells while its signaling activity could impact on both the mesoderm and the neural crest cells. In contrast, Fgf8 is predominantly expressed in the cranial neural crest cells and it influences skeletal development and myogenesis in the cranial mesoderm. WNT signaling, which emanates from the cranial neural crest cells, interacts with BMP and FGF signaling in monitoring the switch between tissue progenitor expansion and differentiation. The transcription factor Twist1, a critical molecular regulator of many aspects of craniofacial development, coordinates the activity of the above pathways in cranial mesoderm and cranial neural crest tissue compartments.
... Facial bones are surrounded by fibrous periosteal capsules that are fully established by the seventeenth week of gestation, whereas cranial bones develop in a preformed continuous fibrous membrane and only develop fibrous capsules after birth [71]. Unlike facial sutures, which close around the 7th-8th decades, cranial sutures close earlier in life [72]. Hence, for the purpose of this review we will focus exclusively on sutures of the cranial vault. ...
Cranial bones articulate in areas called sutures that must remain patent until skull growth is complete. Craniosynostosis is the condition that results from premature closure of one or more of the cranial vault sutures, generating facial deformities and more importantly, skull growth restrictions with the ability to severely affect brain growth. Typically, craniosynostosis can be expressed as an isolated event, or as part of syndromic phenotypes. Multiple signaling mechanisms interact during developmental stages to ensure proper and timely suture fusion. Clinical outcome is often a product of craniosynostosis subtypes, number of affected sutures and timing of premature suture fusion. The present work aimed to review the different aspects involved in the establishment of craniosynostosis, providing a close view of the cellular, molecular and genetic background of these malformations.
... Tatsachen ! Während des Alterungsprozesses verknçchern nicht alle Schädelnähte, und ein Teil der Schädel- platten ist gegeneinander beweglich [9]. Eine ge- ringe Beweglichkeit in den Schädelnähten wird heute allgemein anerkannt [12]. ...
Im Jahr 2001 las ich einen Beitrag in der Zeit-schrift Physical Therapy mit dem Titel Challen-ging Myths in Physical Therapy [5]. Darin kritisier-te Susan Harris, Professorin an der Universität von Vancouver, dass Physiotherapeuten ganz im Widerspruch zur wissenschaftlichen Evidenzla-ge die Kraniosakraltherapie bei einer Vielzahl von Beschwerden als Behandlung 1. Wahl einset-zen. Heute – 6 Jahre später – hat sich die Beweis-lage nicht zugunsten der Kraniosakraltherapie geändert. Nichtsdestotrotz wachsen Nachfrage und Angebot in diesem Bereich stetig. Im Folgenden lesen Sie eine kritische Auseinan-dersetzung mit diesem Mythos – unvollständig, unbequem, anspruchslos, auf-und anregend. Historisch ! Vor mehr als 100 Jahren erklärten anerkannte Experten, dass es den kraniosakralen Rhythmus gibt. Dem US-Amerikaner William Garner Sut-herland wird eine Eingebung im Jahre 1899 zu-geschrieben. Er betrachtete einen zerlegten Schädel in einer Vitrine und schlussfolgerte, dass die Schädelnähte existieren, um den ein-zelnen Schädelknochen Bewegungen für einen "primär respiratorischen Mechanismus" zu er-mçglichen. Sein Buch The Cranial Bowl erschien 1939 [14]. John E. Upledger prägte in den letzten 25 Jahren das kraniosakrale Konzept und verçffentlichte im Jahr 1983 sein Buch Craniosacral Therapy [16].
... Regardless a considerable inter-individual variability was found in the midpalatal inter-digitation and obliteration parameters, 17,21 a slow expansion protocol, with activation of one-quarter of a turn per day was considered with the main purpose of allowing adequate tissues adaptation to exerted forces and minimizing patient's discomfort, especially due to increased maxillary bone stiffness with age. 17, [22][23][24][25] A non-extraction treatment approach was possible due to the arch length increase provided by both maxillary expansion and monocortical miniscrew mechanics. A combined intrusive and retraction system was applied to the maxillary right segment in order to correct the Class II subdivision relationship 26 as well as provide enough space for upper teeth alignment. ...
Introduction:
Etiology of dental crowding may be related to arch constriction in diverse dimensions, and an appropriate manipulation of arch perimeter by intervening in basal bone discrepancies cases, may be a key for crowding relief, especially when incisors movement is limited due to underlying pathology, periodontal issues or restrictions related to soft tissue profile.
Objectives:
This case report illustrates a 24-year old woman, with maxillary transverse deficiency, upper and lower arches crowding, Class II, division 1, subdivision right relationship, previous upper incisors traumatic episode and straight profile. A non-surgical and non-extraction treatment approach was feasible due to the miniscrew-assisted rapid palatal expansion technique (MARPE).
Methods:
The MARPE appliance consisted of a conventional Hyrax expander supported by four orthodontic miniscrews. A slow expansion protocol was adopted, with an overall of 40 days of activation and a 3-month retention period. Intrusive traction miniscrew-anchored mechanics were used for correcting the Class II subdivision relationship, managing lower arch perimeter and midline deviation before including the upper central incisors.
Results:
Post-treatment records show an intermolar width increase of 5 mm, bilateral Class I molar and canine relationships, upper and lower crowding resolution, coincident dental midlines and proper intercuspation.
Conclusions:
The MARPE is an effective treatment approach for managing arch-perimeter deficiencies related to maxillary transverse discrepancies in adult patients.
... It has been shown that the bony obliteration of the facial sutures takes place much later than that of the calvarial suture. 20 In particular, the onset of the midpalatal suture fusion has been shown to be the fourth decade of life, [21][22][23] implicating both the possibility and uncertainty of orthopedic expansion in young adults. This notion is contradicted by early comments on suture 'fusion' at around 15 years of age. ...
... Chaconas and Caputo stated that the major resistance to rapid palatal expansion forces was not the suture but other articulations in the maxilla, such as the zygotic and spheroidal sutures [1]. Conventionally, Surgically Assisted RPE (SARPE) has been applied to overcome the decreased elasticity of bone and increased resistance of interdigitated mid-palatal suture in adults [2][3][4]. ...
... However, the progressive calcification and interdigitation of circummaxillary sutures in older patients reduces the efficiency of RME [6]. When there is no potential to open the midpalatal suture with RME in adult patients, surgically assisted rapid palatal expansion (SARPE) may be an option [7,8]. Nevertheless, this technique is invasive and can lead to side effects, such as periodontium injuries, root resorption [9] and sinus infection [10]. ...
Objectives
To assess in-vitro trabecular bone damage following mono- and bicortical mini-implant (MI) anchorage in mini-implant assisted rapid palatal expansion (MARPE).
Material and methods
Sixteen self-drilling MI (four MARPE appliances) were distributed in two groups according to bone insertion (monocortical and bicortical) in bovine rib. The device was activated five times (0.5 mm each). Trabecular bone damage was assessed using micro-CT scans made at baseline and after each activation by trabecular spacing parameter (Tb.Sp) (distance [mm] between the trabecular bone structure). These measurements were made in five different regions of interest (ROI) surrounding the screw (whole, superior, inferior, anterior and posterior). Two-way ANOVA with Tukey post-hoc analysis (α = 0.05) was used to evaluate the effect of insertion type (monocortical vs. bicortical) and activation cycle (0–5) on trabecular damage. The time effect was evaluated using ANOVA-MR test effect with Bonferroni correction (α = 0.003). The micro-CT images were also examined qualitatively.
Results
When analysing the individual ROIs, only the superior ROI had a significant difference (P < 0.003) beginning at the fourth activation cycle. For the monocortical group, trabecular spacing was affected when the whole ROI was analysed beginning at the fourth activation cycle, while for the superior ROI, this difference became apparent beginning with the third activation cycle (P < 0.003). For the qualitative analysis, it seems that only monocortical anchorage influences the trabecular bone in the superior area.
Conclusions
Monocortical anchorage is more susceptible to bone damage around the MIs, with the superior (cervical) region most strongly affected.
... However, the fused, mature midpalatal suture and adjacent articulations limit the desired results for nongrowing patients using conventional RME. 6,7 Conventional tooth-anchored RME use could cause dentoalveolar tipping, less skeletal movement, and lack of long-term stability. 8,9 To reduce possible unwanted side effects, miniimplant-assisted rapid maxillary expansion (MARME) was designed to increase the maxillary width in nongrowing patients using four mini-implants placed in the cortical bone of the palate and nasal floor (NF). ...
Objectives
To observe skeletal width changes after mini-implant–assisted rapid maxillary expansion (MARME) and determine the possible factors that may affect the postexpansion changes using cone-beam computed tomography (CBCT) in young adults.
Materials and Methods
Thirty-one patients (mean age 22.14 ± 4.76 years) who were treated with MARME over 1 year were enrolled. Four mini-implants were inserted in the midpalatal region, and the number of activations ranged from 40 to 60 turns (0.13 per turn). CBCT was performed before MARME (T0), after activation (T1), and after 1 year of retention (T2). The mean period between T1 and T0 was 6 ± 1.9 months and between T2 and T1 was 13 ± 2.18 months. A paired t-test was performed to compare T0, T1, and T2. The correlations between the postexpansion changes and possible contributing factors were analyzed by Pearson correlation analysis.
Results
The widths increased significantly after T1. After T2, the palatal suture width decreased from 2.50 mm to 0.75 mm. From T1 to T2, decreases recorded among skeletal variables varied from 0.13 mm to 0.41 mm. This decrease accounted for 5.75% of the total expansion (2.26 mm) in nasal width (N-N) and 19.75% at the lateral pterygoid plate. A significant correlation was found between postexpansion change and palatal cortical bone thickness and inclination of the palatal plane (ANS-PNS/SN; P < .05).
Conclusions
Expanded skeletal width was generally stable after MARME. However, some amount of relapse occurred over time. Patients with thicker cortical bone of the palate and/or flatter palatal planes seemed to demonstrate better stability.
... For example in the human, the sagittal and midpalatal sutures are of the end-to-end type (Cohen Jr, 1993) as are the metopic and intemasal in the rat (Koskinen, 1977). All other sutures are of the overlapping type and include the coronal and frontozygomatic (Kokich, 1976;Koskinen, 1977). It has been proposed that midline sutures may be of the end-to-end type because the biomechanical forces on either side of this region are quite likely to be equal in magnitude. ...
Craniosynostosis is a disease that afflicts approximately 1 in 2500 children worldwide. It is caused by the premature fusion of the cranial sutures which normally function as proliferation centres allowing the expansion of the skull during the growth of the brain and facial region. Affected children have major abnormalities including underdevelopment of the midface, limb defects, raised intracranial pressure, breathing problems as a result of airway restriction and severe learning difficulties. In 1994 a mutation in the Fibroblast Growth Factor Receptor 2 (FGFR2) gene was found in patients with Crouzon syndrome, one of the craniosynostoses and subsequently mutations in FGFRs 1-3 have accounted for many of these syndromes. Very little is known to date about the mechanisms which generate normal and abnormal phenotypes and in this Thesis, a model system has been used to elucidate the developmental pathways responsible. A grafting technique has been used to manipulate developing embryonic chick crania and perturb morphogenesis. Implantation of beads soaked in the ligand FGF-2 did not affect normal cranial development at biological concentrations. In the limb bud however, these same beads elicited dramatic changes in morphogenesis demonstrating that these beads are biologically active. Implantation of beads soaked in a neutralising antibody to FGF-2 resulted in a graded response. When a single bead is implanted thereby reducing the active levels of endogenous FGF-2 protein, the grafts grew to a massive size as a result of increased cell division in the tissue. By using a technique to detect proliferating cell nuclei immunohistochemically it is clear that in these large grafts almost all nuclei are undergoing cell division whereas in control grafts the opposite is the case. With greater inactivation of FGF-2 protein (2-3 antiFGF-2 loaded beads implanted) further bone differentiation was blocked and the level of cell proliferation was reduced below background levels. It is proposed that a multi-stage signalling cascade operates within the skull such that at low levels of FGF, proliferation occurs and at higher levels, these cells are further induced to differentiate into bone. Conversely, when FGF is blocked and the amount available to receptors is reduced, cranial bone morphogenesis is prevented. These results relate to the clinical situation since the majority of mutations in FGFRs in patients with craniosynostosis are thought to result in increased receptor activation equivalent to an increase in FGF signalling. Hence the effect is premature differentiation of cranial sutures into bone.
... [9][10][11] Erks are the members of the family of intracellular serine-threonine kinases (mitogenactivated protein kinases) and are known as essential mediators of the growth-factor-induced cell proliferation and differentiation in various cell types including osteoblasts. [12] Unlike the calvarial sutures showing obliteration at various ages, [1,13] facial suture has been shown to maintain the patency even at late phase in the lifetime. [14] Contact with the dura mater is exclusive in the cranial sutures, implicating the regulation by dura mater. ...
Objectives
The suture is a fibrous tissue intervening two adjacent bone segments, existing only in the craniofacial region. In spite of wide use of palatal expansion in various ages, the age-dependent cellular mechanism for osteogenesis is largely unknown. The aim of this study was to examine the proliferation and differentiation pattern of the suture cells on lateral expansion in rats depending on the ages.
Materials and Methods
Calibrated lateral tensile stress of 50 g was given to the male Sprague-Dawley rat incisors using a double helix in 30 young (10 weeks) and another 30 aged (52 weeks) group, respectively. Each group was subdivided into control, 1, 3, 7, 14, and 21 days, with five animals in each group. Premaxilla area was retrieved from each animal for further histologic analyses including H and E, Masson’s trichrome, and immunohistochemical staining using antibodies against phospho-extracellular signal-regulated kinase, proliferating cell nuclear antigen (PCNA), and fibroblast growth factor receptor-2 (FGFR2). Positive cell counts in the region of interest were conducted.
Results
Gross suture separation and subsequent bone formation on the sutural side bone surface were observed in both groups, characterized as active collagen turnover, remarkable woven bone projection toward the sutural mesenchyme and subsequent maturation in 3 weeks. Increase in PCNA- and FGFR2-postive cell proportions were comparable in both groups, indicating similar time- and area-specific proliferation and osteogenic differentiation patterns in the stretched suture regardless of the age groups.
Conclusion
According to the results, it can be implicated that the tensile stress applied to the suture in the adult group may induce active bone formation similar to that in young group, in associated with FGFR2 and Erk signaling cascade. Mesenchymal cells in the premaxillary suture appear to retain remarkable potential for further proliferation and differentiation even in aged subjects.
... Some previous studies indicated that an applianceinduced palatal bone split may be attributable to multiple factors rather than simply being caused by suture ossification. [9][10][11] Although chronological age was considered as a conventional RPE indicator, [12][13][14] this assumption remains controversial. 15 In addition, given the physical phenomena involved in MARPE, palatal shape (length and depth) may also be a contributing factor. ...
Objective:
We sought to determine the predictors of midpalatal suture expansion by miniscrew-assisted rapid palatal expansion (MARPE) in young adults.
Methods:
The following variables were selected as possible predictors: chronological age, palate length and depth, midpalatal suture maturation (MPSM) stage, midpalatal suture density (MPSD) ratio, the sella-nasion (SN)-mandibular plane (MP) angle as an indicator of the vertical skeletal pattern, and the point A-nasion-point B (ANB) angle for anteroposterior skeletal classification. For 31 patients (mean age, 22.52 years) who underwent MARPE treatment, palate length and depth, MPSM stage and MPSD ratio from the initial cone-beam computed tomography images, and the SN-MP angle and ANB angle from lateral cephalograms were assessed. The midpalatal suture opening ratio was calculated from the midpalatal suture opening width measured in periapical radiographs and the MARPE screw expansion. Statistical analyses of correlations were performed for the entire patient group of 31 subjects and subgroups categorized by sex, vertical skeletal pattern, and anteroposterior skeletal classification.
Results:
In the entire patient group, the midpalatal suture opening ratio showed statistically significant negative correlations with age, palate length, and MPSM stage (r = -0.506, -0.494, and -0.746, respectively, all p < 0.01). In subgroup analyses, a strong negative correlation was observed with the palate depth in the skeletal Class II subgroup (r = -0.900, p < 0.05).
Conclusions:
The findings of this study indicated that age, palate length, and MPSM stage can be predictors of midpalatal suture expansion by MARPE in young adults.
The anatomy of the extant lepidosaur Sphenodon (New Zealand tuatara) has been extensively examined by palaeontologists and comparative anatomists because of its phylogenetic status as the only living member of the Rhynchocephalia. It is also of interest because of its sophisticated feeding apparatus and a prooral (anteriorly directed) mode of shearing used to rip food apart. However, despite several detailed descriptions of the skull, the three-dimensional relationship between individual bones of the skull has generally been ignored. Here we provide the first joint by joint description of the hard tissue anatomy for almost every cranial suture in the skull of Sphenodon. This survey shows that most joints involve either abutments (e.g., along the midline) or extensive overlaps (e.g., more peripheral areas) but there are others that are heavily interlocked (e.g., postorbital-postfrontal) or involve a notable amount of soft tissue (e.g., vomer-premaxilla). There is variation in facet surface texture (e.g., smooth, ridged, pitted) but extensive interdigitation is uncommon and generally restricted to one plane. The joints do not appear suited to promote the marked intracranial movement reported in lizards such as geckos. However, it is possible that the base of the premaxillae would have been able to pivot slightly when loaded or impacted by the lower jaw during shearing. The extensive overlapping joints probably serve to maximise the surface area available for soft tissues that can dissipate and redistribute stress while maintaining the rigidity of the skull. These joints are larger in adults which bite more forcefully and may feed on harder prey.
Histologische Untersuchungen haben gezeigt, da der Zeitpunkt fr die Suturenschlieung groen individuellen Schwankungen unterliegt. Eine orthodontische Behandlung, entweder in Form einer Dehnung oder Kompression der Sutura, sollte frhzeitig eingesetzt werden. Der beste Zeitpunkt fllt daher in das Wechselgebi, weil die eruptierenden Prmolaren und Eckzhne in einen Zahnbogen durchbrechen, der in Anpassung an die Mandibula transversal hinreichend verbreitert worden ist.Histological studies have shown that great variations exist among individuals over the age at which the sutures commence to close. An orthodontic treatment such as expansion or compression of the mid-line suture, should therefore be started early. The best period seems to be during the mixed dentition. The premolars and canines can then erupt into a maxillary dental arch which has been widened transversally so that it corresponds with that of the mandible.Des tudes histologiques ont montr qu'il y a de grandes variations individuelles concernant l'ge o les sutures maxillaires se ferment. Un traitement par expansion ou compression de la suture maxillaire devrait dbuter prcocment. Le meilleur moment se situe pendant la priode de denture mixte; le maxillaire ayant t largi au pralable, canines et prmolaires peuvent faire ruption et engrner correctement avec la mandibule.
The purpose of this paper is to provide a new perspective on craniosynostosis by correlating what is known about sutural biology with the events of craniosynostosis per se. A number of key points emerge from this analysis: (1) Sutural initiation may take place by over lapping, which results in beveled sutures, or by end-to-end approximation, which produces nonbeveled, end-to-end sutures. All end-to-end sutures occur in the midline (e.g., sagittal and metopic) probably because embryonic biomechanical forces on either side of the initiating suture tend to be equal in magnitude. A correlate appears to be that only synostosed sutures of the midline have pronounced bony ridging. (2) Long-term histologic observations of the sutural life cycle call into question the number of layers within sutures. The structure varies not only in different sutures, but also within the same suture over time. (3) Few, if any, of the many elegant experimental research studies in the field of sutural biology have increased our under standing of craniosynostosis per se. An understanding of the pathogenesis of craniosyn ostosis requires a genetic animal model with primary craniosynostosis and molecular techniques to understand the gene defect. This may allow insight into pathogenetic mechanisms involved in primary craniosynostosis. It may prove to be quite heterogeneous at the basic level. (4) The relationship between suture closure, cessation of growth, and functional demands across sutures poses questions about various biological relationships. Two conclusions are provocative. First, cessation of growth does not necessarily, or always lead to fusion of sutures. Second, although patent sutures aid in the growth process, some growth can take place after suture closure. (5) In an affected suture, craniosynostosis usually begins at a single point and then spreads along the suture. This has been shown by serial sectioning and calls into question results of studies in which the affected sutures are only histologically sampled. (6) Craniosynostosis is etiologically and pathogenetically heterogeneous. Known human causes are reviewed. Is craniosynostosis simply normal suture closure commencing too early? In hyperthyroidism, this is probably the case, but in Apert syndrome, true sutures in the sagittal and metopic regions fail to form ab initio. The actual mechanisms that result in pathologic synostosis, although incompletely understood, must be heterogeneous in nature. (7) Special topics are analyzed and discussed including fetal head constraint, the calvaria in Apert syndrome and holoprosencephaly, a critique of Moss's theory, calcified cephalohematoma, secondary cartilage, paradoxical craniosynostosis, and delayed suture closure. (8) The effect of craniosynostosis on the calvaria and the cranial base is discussed; it is shown that the relationship between the calvaria and the cranial base varies and reflects several different factors such as whether or not the basal portion of the coronal ring is involved and whether the synostosis is isolated or syndromic. (9) Simple craniosynostosis involving the coronal suture may produce significant effects on the midface. Restricted coronal suture growth is the primary effect, changes in the cranial base the secondary effect, and foreshortening of the midface the tertiary effect. The effects follow a temporal sequence. In general, the degree of midface shortening is a function of which suture is restricted from growing, how early growth restriction of the suture takes place, and how much time elapses before measuring the effects on the midface. This model of craniofacial change is only applicable to simple craniosynostosis, not to cases with complete coronal ring involvement or to syndromic cases such as Apert or Crouzon syndromes. © 1993 Wiley-Liss, Inc.
An analysis of past experimental and clinical studies on orthopedic changes of craniofacial bones is presented. The theoretical aspects and technical improvements necessary for relating biomechanical principles to attain the desired alterations in craniofacial morphology are discussed. A critical evaluation of the past measurements and histologic techniques is also presented. Suggestions are given for directions to future research methodology which can offer reliable results.
Premature fusion of cranial sutures is a common problem with an incidence of 3-5 per 10,000 live births. Despite progress in understanding molecular/genetic factors affecting suture function, the complex process of premature fusion is still poorly understood. In the present study, corresponding excised segments of nine patent and nine prematurely fused sagittal sutures from infants (age range 3-7 months) with a special emphasis on their hierarchical structural configuration were compared. Cell, tissue and architecture characteristics were analysed by transmitted and polarised light microscopy, 2D-histomorphometry, backscattered electron microscopy and energy-dispersive-x-ray analyses. Apart from wider sutural gaps, patent sutures showed histologically increased new bone formation compared to reduced new bone formation and osseous edges with a more mature structure in the fused portions of the sutures. This pattern was accompanied by a lower osteocyte lacunar density and a higher number of evenly mineralised osteons, reflecting pronounced lamellar bone characteristics along the prematurely fused sutures. In contrast, increases in osteocyte lacunar number and size accompanied by mineralisation heterogeneity and randomly oriented collagen fibres predominantly signified woven bone characteristics in patent, still growing suture segments. The already established woven-to-lamellar bone transition provides evidence of advanced bone development in synostotic sutures. Since structural and compositional features of prematurely fused sutures did not show signs of pathological/defective ossification processes, this supports the theory of a normal ossification process in suture synostosis - just locally commencing too early. These histomorphological findings may provide the basis for a better understanding of the pathomechanism of craniosynostosis, and for future strategies to predict suture fusion and to determine surgical intervention.
Decompression Sickness (DCS) results from exposure to reduced environmental pressure. As a result excess nitrogen evolves from tissues. This gas may then form bubbles that may localize in tissue or the vessels. They then create symptoms that range from mild to severe. Commonly, mild symptoms are joint pains and are called Type I DCS. Severe symptoms can run a range of neurological manifestations and are called Type II DCS. The basis for this paper stems from two cases seen in the Davis Hyperbaric Laboratory and Air Force Research Laboratory at Brooks Air Force Base, Texas.
Continuing periosteal apposition (CPA) of small amounts of new lamellar bone, leading to absolutely larger size, has been identified in a number of adult cranial and postcranial bones. This paper reviews 42 studies published since 1964 that have found both significant and nonsignificant age-related change in various skeletal size dimensions, e.g., length, diameter, width, and area. Also considered are four hypotheses that have, or may be, postulated for the occurrence of CPA. To date, however, these hypotheses (cohort effect, mechanical compensation, bone repair and/or mechanical response potential, and heterochrony) have not been rigorously tested, hence remain speculative. An important interpretive problem that befalls the investigation of CPA is its small effect size (i.e., the magnitude of change between observations), since most studies have restricted sample sizes. This problem is illustrated by power analysis of three reviewed studies that reported nonsignificant age-related change. The analysis indicates that these studies had very little likelihood of finding a statistically significant result, i.e., a low probability of rejecting the null hypothesis stipulating no size change with age. This finding has implications for interpreting CPA and for distinguishing between the statistical and biological significance of this phenomenon.
A 13-month-old dog was investigated for the complaint of open-mouth locked jaw. There were not any previous episodes of trauma witnessed. Computed tomographic evaluation revealed unilateral zygomatico-temporal synostosis and associated craniofacial asymmetry, with impingement of the mandibular coronoid process resulting in unilateral temporomandibular joint subluxation. Closed reduction of the subluxation was not maintained. Partial zygomatico-temporal suturectomy resulted in resolution of the clinical signs. To the author's knowledge, isolated zygomaticotemporal syno-stosis with associated temporomandibular subluxation has not been reported in the dog.
Developmental processes or changes in morphology continue after puberty. Ageing is difficult to define, since it is a continuous process and it is impossible to distinguish between effects related only to time and the effects of degenerative diseases. These diseases are the cause or the result of senescence. The theories of ageing are very numerous but it is quite clear that the processes of formation or destruction are present in all stages from conception to death, the ratio between the processes being, however, different. There is no clear starting point of senescence.
Initial reactions to tensile forces of up to 3.5 N per side applied to the maxilla of a macerated Macaca mulatta skull were determined with holographic interferometry. Displacements ranged from 0 μm to 22 μm depending on the force magnitude and the point of observation. A complicated force-coordinated pattern of shearing and compression in the sutures occurred. The results appear comparable to similar experiments in dry human skulls and analogous to the effects observed in long-term experiments in living animals.
Surgically Assisted Rapid Maxillary Expansion (SARME) is frequently used to treat skeletal maxillary transverse deficiency (MTD) in skeletally mature and non-growing individuals. Despite previous research in the field, questions remain with respect to the long-term stability of SARME and its effects on hard and soft tissue. The overall aim of the present doctoral work was to achieve a greater understanding of SARME, using modern image technology and a multidisciplinary approach, with special reference to effects on the hard and soft tissues and respiration. A more specific aim was to evaluate the long-term stability in a retrospective sample of patients treated with SARME and orthodontic treatment and to compare the results with a matched, untreated control group. The studies in this doctoral project are thus based on two different samples and study designs. The first sample, Study I (Paper I), is a retrospective, consecutive, long-term follow-up material of study models from 31 patients (17 males and 14 females) treated with SARME and orthodontic treatment between 1991 and 2000. The mean pre-treatment age was 25.9 years (SD 9.6) with a mean follow-up time of 6.4 years (SD 3.3). Direct measurements on study models were made with a digital sliding caliper at reference points on molars and canines. To evaluate treatment outcome and long-term stability, the results were compared with study models from an untreated control group, matched for age, gender and follow-up time. The second sample, Study II (Papers II-IV), is a prospective consecutive, longitudinal material of 40 patients scheduled to undergo SARME and orthodontic treatment between 2006 and 2009. In Paper II, one patient was excluded because of a planned adenoidectomy. The final sample comprised 39 patients (16 males and 23 females). The mean age at treatment start was 19.9 years (range 15.9 - 43.9). Acoustic rhinometry, rhinomanometry and a questionnaire were used to assess the degree of nasal obstruction at three time-points; pre-treatment, three months after expansion and after completed treatment (mean 18 months). In Papers III-IV, three patients declined to participate and two had to be excluded because their CT-records were incomplete. The final sample comprised 35 patients (14 males and 21 females). The mean age at treatment start was 19.7 years (range 16.1 - 43.9). Helical CT-images were taken pre treatment and eighteen months' post-expansion. 3D models were registered and superimposed at the anterior cranial base. The automated voxel-based image registration method allows precise, accurate measurements in all areas of the maxilla. In Papers II-IV, the treatment groups constituted their own control groups. The main findings in the retrospective, long-term follow-up study were that SARME and orthodontic treatment normalized the transverse discrepancy and was stable for a mean of 6 years post-treatment. Pterygoid detachment did not entirely eliminate the side effect of buccal tipping of the posterior molars. Relapse is time-related and is most pronounced during the first 3 years after treatment. Thus the retention period should be extended and should be considered for this period. The main rhinological findings in the prospective longitudinal study were that SARME had a short-term, favourable effect on nasal respiration, but the effect did not persist in the long-term. However, subjects with pretreatment nasal obstruction reported a lasting sensation of improved nasal function. SARME and orthodontic treatment had a significant but non-uniform skeletal treatment effect, with significantly greater expansion posteriorly than anteriorly. The expansion was parallel anteriorly but not posteriorly. The lateral tipping of the posterior segment was significant, despite careful surgical separation. No correlation was found between tipping and the patient's age. Furthermore, SARME and orthodontic treatment significantly affected all dimensions of the external features of the nose. The most obvious changes were at the most lateral alar-bases. The difference in lateral displacement profoundly influenced the perception of a more rounded nose. There were no predictive correlations between the changes. Patients with narrow and constrained nostrils can benefit from these changes with respect to the subjective experience of nasal obstruction. It is questionable whether an alar-cinch suture will prevent widening at the alar-base. The 3D superimposition applied in Study II is a reliable method, circumventing projection and measurement errors. In conclusion, SARME and orthodontic treatment normalize the transverse deficiency, with long-term stability. SARME has a favourable effect on the subjective perception of nasal respiration. SARME significantly affects dental, skeletal and nasal structures.
Objectives
There is ongoing debate over the existence of cranial motion resulting from manual manipulation during Cranial Osteopathy (CO). The purpose of this study was to review and summarize the literature regarding cranial mobility and human cranial stiffness in order to evaluate the validity of cranial movement in humans due to manual manipulation.Methods
In Part I, the literature was reviewed to determine the existence and extent of cranial motion in animals and humans. In Part II, the literature was reviewed to determine the stiffness of the human cranium. In Part III, a biomechanical analysis was performed to determine the amount of force necessary to cause cranial deflections reported in the studies identified in Part I, using published skull stiffness values reported in the studies identified in Part II.ResultsSkull deflection across the cranial sutures of animals ranged from 0 μm to 910 μm. Cranial vault deflection in living humans was reported to range from 0.78 μm to 3.72 μm. Reported human skull stiffness values ranged from 390 N/mm to 6430 N/mm depending on the region of the skull and the method of loading. Based on the range of skull stiffness values, it was determined that an applied force between 0.44 N and 23.2 N would be required to cause 0.78 μm of deflection, and between 2.09 N and 111 N would be required to cause 3.72 μm of deflection.Conclusion
Externally applied forces and increases in intracranial pressure can result in measurable cranial motion across the cranial sutures in adolescent and adult mammalian animal species, and measurable changes in cranial vault diameter in post-mortem and living adult humans. However, the amount of cranial motion may vary by subject, the region of the head to which forces are applied, and the method of force application. Given that the forces required to generate reported cranial deflections in living humans are within the range of forces likely to be used during CO, it is reasonable that small amounts of cranial deflection can occur as a result of the forces applied to the skull during CO.
Der von den Vertretern der CSO postulierte autonome Rhythmus des Liquor cerebrospinalis im Sinne des sog. primären respiratorischen Mechanismus lässt sich bisher ebenso wenig nachweisen, wie eine aktive Beweglichkeit der Schädelknochen in ihren Nähten. Eine passive Beweglichkeit bis ins hohe Alter ist dagegen unstrittig. Die von den CSO-Therapeuten wahrgenommenen Bewegungen stammen nach heutigem Stand nicht aus dem Körper des Patienten. Es handelt sich sehr wahrscheinlich um Bewegungen, die der Therapeut in einem Zustand entspannter Meditation oder selbstinduzierter Trance als eine ,,Energieschwingung“ zwischen seinen Händen aufbaut. Der wahrscheinliche Bezug zu Puls und Atmung des Therapeuten ist noch nicht wirklich aufgeklärt. Möglich wäre eine Korrelation auf der Ebene von Schwingungsknoten bei der Überlagerung verschiedener Frequenzen. Die vom Therapeuten generierten Schwingungen werden in den Schädel des Patienten eingeleitet, der darauf im Sinne einer passiven Mitbewegung reagieren oder möglicherweise der Schwingungsinduktion einen durch eine Funktionsstörung bedingten Widerstand entgegensetzen kann. Die positive und zuverlässige Umsetzung dieser Information in therapeutische Aktionen durch einen Therapeuten konnte trotz entsprechender Kenntnisse von Anatomie und Biomechanik bisher nicht belegt werden. Nur durch eine auch im naturwissenschaftlichen Denken stichhaltige Erklärung der empirischen Beobachtungen der CSO wäre eine Integration dieser Methode in die manuelle Medizin möglich.
The sutures of the face are mostly paired sutures, except the median palatine, intermaxillary, and internasal sutures. Many of them are located in and around the orbit and are related to facial fractures and surgery of the orbit. In this chapter, we discuss the anatomy of the sutures of the face and its clinical implications.
Introduction:
In this study, we experimentally evaluated whether complex, mature sutures can be separated using skeletal anchorage and light, continuous forces.
Methods:
Twelve adult, 8- to 9-month-old female New Zealand white rabbits were randomly assigned to 1 control group and 2 experimental groups. Open-coil nickel-titanium springs delivered constant forces of 100 g across the sagittal suture to miniscrew implants placed bilaterally in the frontal bone. Sutural separation was measured biweekly. Separation was also measured with microcomputed tomography. Bone formation (mineral apposition) was measured with fluorescent labels. Qualitative histologic analyses of the suture tissues were performed using hematoxylin and eosin staining; osteoclasts were evaluated with tartrate resistant acid phosphatase staining.
Results:
All 24 miniscrew implants remained stable throughout the experiment. There was no statistically significant sutural separation in the control group. In the experimental groups, sutural separation was significant (P <0.05) at all time points after the initial records were taken. The rate of separation was linear during the first 42 days. There were moderate correlations (R = 0.59-0.89; P <0.05) between miniscrew implant separation and bone marker separation. Mineral apposition rate, which was not measureable in the control group, was significant in the experimental group. The mineral apposition rate was greater between 14 and 28 days than between 28 and 38 days, and it was greater on the ectocranial than on the endocranial surface. Based on the microcomputed tomography analysis, 3-dimensional sutural volume of the experimental group increased significantly (P = 0.02), but surface area did not (P = 0.26).
Conclusions:
It is possible to separate the sagittal suture of mature rabbits. Sutural separation is limited, indicating involvement of other articulations.
Surgically-assisted rapid maxillary expansion (SARME) is a technique used to widen the maxilla, and we present the results of our long-term follow up (6.5 years). Seventeen patients who had been treated with SARME and prospectively followed were invited for long-term follow up by dental casts and posteroanterior cephalograms. The following measurements were made on the dental casts: transverse distances at canine, premolar, and molar level, length of the arch, and width and depth of the palate at premolar and molar level. The distance between the left and right nasal bases and the widening of the inferior maxilla were measured on the posteroanterior cephalograms. Boneborne and toothborne distractors were used in 8 and 9 patients, respectively. In the study of dental casts, there was a significant increase in transverse width in the canine (P < 0.001), premolar (P < 0.001) and molar (P = 0,001) and these remained stable in the long term. The arch length did not increase significantly, but the palatal width increased significantly in the premolar (P < 0.001) and molar (P = 0.001) regions. No effect was seen in palatal depth. On the posteroanterior cephalograms the width of the inferior part of the maxilla was increased, but not significantly so. There were no significant changes at the nasal base. We conclude that SARME is a predictable technique to widen the maxilla in the long term.
Objective:
The present study compared the skeletal effects of surgically assisted rapid maxillary expansion (SARME) with different surgeries in three representative finite element (FE) models.
Study design:
According to the ossification level of midpalatal suture, three FE models, with different elasticity moduli of sutures (E = 1 MPa, 500 MPa, and 13,700 MPa) were constructed, to represent three age groups of patients. Within each model, four groups were set up according to different surgeries: group I (control group without surgery), II (paramedian osteotomy), III (pterygomaxillary separation), and IV (paramedian osteotomy and pterygomaxillary separation). An expansion force of 100 N and 1 mm displacement were applied via a bone-borne distraction to simulate the expansion process.
Results:
By analyzing these models, the maximum displacement of maxilla was observed in group IV, with E = 1 MPa model exhibiting the most displacement (28.5 × 10-6 mm), followed by group II (21.4 × 10-6 mm). Group IV showed a unique backward-downward rotation with minimum stress distributions in three models (9 MPa, 131 MPa, and 140 MPa, respectively), and group II exhibited comparable low stress distributions (12 MPa, 151 MPa, and 230 MPa, respectively). Lowest stress was found in E = 1 MPa model, compared with the other two models.
Conclusion:
There is no need to perform surgeries when the midpalatal suture is open, and surgery guidelines are the same for partial and complete fusion sutures. Furthermore, exclusive use of partial paramedian osteotomy is sufficient enough to reduce stress and expand the posterior part of maxilla, and it is less invasive.
Adolescence represents an extremely important time in the dental care of the pediatric patient. Health care professionals who interact with adolescents should recognize that it is a time of unprecedented change. It is the transitional period between puberty and maturity where accelerated physical growth and dynamic hormonal change are accompanied by heightened self-awareness and social maturity. As adolescents begin to develop more independence, the responsibility of dental home care should be managed effectively by themselves rather than by their parents. The dentist is in a unique position among health care professionals to guide the adolescent’s oral health because of the frequent recall examinations. In turn, the adolescent should have more opportunities to discuss some of the physical, psychosocial, and risky behavioral issues that may impact his or her oral health. The practitioner must have the requisite knowledge of adolescent oral health concerns and be able to apply the principles of anticipatory guidance to the adolescent’s dental care. In addition, the dentist needs to be an excellent clinician as well as an exceptional educator and communicator in providing information that is clinically relevant and psychologically sensitive to meet the teenager's needs.
Introduction
The objective of this research was to observe changes in aerodynamics and anatomic characteristics of the upper airway after mini-implants assisted rapid maxillary expansion and to evaluate the correlation between the 2 changes of the upper airway in young adults.
Methods
Thirty consecutive patients (mean age, 23.82 ± 3.90 years; median, 24.5 years; 9 males, 21 females) were involved. Cone-beam computed tomography was taken before activation and over 3 months. Three-dimensional models of the upper airway were reconstructed on the basis of cone-beam computed tomography. The anatomic characteristics of the upper airway, including volume, area, transverse, and sagittal diameter, were measured. The aerodynamic characteristics of the upper airway were calculated on the basis of 3-dimensional models using computational fluid dynamics. The correlation between the changes in aerodynamics and anatomic characteristics of the upper airway was explored.
Results
The enlargements of the volume of the total pharynx, nasopharynx, and oropharynx were found (9.99%, 20.7%, and 8.84%, respectively). The minimum cross-sectional area increased significantly (13.6%). The airway resistance (R) and maximum velocity (Vmax) decreased significantly in both the inspiration and expiration phase (inspiration: R, −26.8%, Vmax, −15.7%; expiration: R, −24.7%, Vmax, −16.5%). The minimum wall shear stress reduced significantly only in the inspiration phase (−26.3%). The correlations between decreased R and increased volume and minimum cross-sectional area were observed.
Conclusions
Mini-implants assisted rapid maxillary expansion is an effective device for improving anatomic characteristics represented by the total volume of the upper airway and minimum cross-sectional area, which contributed to the respiratory function depending on the favorable changes of aerodynamic characteristics including resistance, velocity, and minimum wall shear stress.
A transverse maxillary deficiency in an adult is a challenging problem, especially when it is combined with a severe anteroposterior jaw discrepancy. The demand for nonsurgical maxillary expansion might increase as patients and clinicians try to avoid a 2-stage surgical procedure-surgically assisted rapid palatal expansion followed by orthognathic surgery-and detrimental periodontal effects and relapse. In this regard, a miniscrew-assisted rapid palatal expansion was devised and used to treat a 20-year-old patient who had severe transverse discrepancy and mandibular prognathism. Sufficient maxillary orthopedic expansion with minimal tipping of the buccal segment was achieved preoperatively, and orthognathic surgery corrected the anteroposterior discrepancy. The periodontal soundness and short-term stability of the maxillary expansion were confirmed both clinically and radiologically. Effective incorporation of orthodontic miniscrews for transverse correction might help eliminate the need for some surgical procedures in patients with complex craniofacial discrepancies by securing the safety and stability of the treatment, assuming that the suture is still patent.
In an attempt to make analysis of stress and strain on the human facial skeleton due to chewing force, a series of experiments were carried out on dry skulls reproducing the mastication, Brief results are shown in Fig. 4 (ditribution of principal strains); Fig. 5 (distribution of strains along the free margins); Fig. 8 (distribution of strain normal to the supposed cross sections); and Fig. 10 (distribution of the maximum absolute values of the strains, i. e., relative strength of various parts), and they are summarized as follows :1) The strains in the facial skeleton increase generally as the load (Pd in Fig. 2 (A)) moves toward the foreteeth in consequence of the increase of the moment of the load about the mandibular joint.2) The direction of the axes of the principal strains changed according to the shift of the load along the dental arch. Nevertheless, the directions in the facial skeleton excluding the lower part of the maxilla and the forehead, are in some measure similar to the orientation of the split-lines.3) Intensive strains appear in the anterior region of the lower part of the maxilla. Fairly intensive strains appear in such region as the nasal root, medial end of the infraorbital margin, infero-lateral corner of the orbit and its inferior vicinity, and the orbital surface of the zygomatic process of the frontal bone.4) Strains in the facial skeleton show the remarkable occurrence of the bending moments.5) The mechanical behavior of the human facial skeleton seems to resemble that of the rigid frame structure.6) The infero-anterior part of the maxilla is relatively weak among various parts of the facial skeleton. This fact may suggest that the human facial skeleton is rather adapted to the use of the posterior teeth.The present study was carried out in the Department of Anthropology, Faculty of Science, University of Tokyo, before the author was transfered to the present institution. The author is deeply grateful to Professor Hisashi SuzuKI of the above department for his guidance and continuous suggestion during the course of the present study. The author also wishes to express his sincere thanks to Professor Teruyoshi UTOGUCHI, Assistant Professor Hiroyuki OKAMURA, and Mr. Shunsaku MITSUHASHI of the Department of Mechanical Engineering, Faculty of Technology, University of Tokyo for their instructive advice during the experiment of the present study.
Microradiographs of undecalcified sections of mandible from twenty-eight individuals aged from 8 weeks to 76 years were assessed for variations in mineralization, bone deposition and resorption, and osteoporosis. The results indicate that there is marked constructive activity in young bone, then a diminution of activity until early middle life. In later middle life and old age there is a comparative rise in bone resorption and osteoporosis and an increased variation in mineral density.
This investigation shows that growth does not cease in the third decade of life, but continues well into older age.
Metabolically normal rabbits, like humans, have specific surface changes in bone remodeling and balance with age. The loss of cortical bone with aging is primarily caused by an endosteal surface negative balance. Since formation rates on these surfaces remain relatively constant with aging, this negative bone balance is the result of increased osteoclastic cell activity. The specific mechanism of this increased osteoclastic activity is not known.
Dentofacial development and growth
- Scott
The mountain of giants: A racial and cultural study of the North Albanian mountain Ghegs
- Coon
Aging of connective tissues
- Milch