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Assessment of soft-tissue vs hard-tissue changes after isolated functional genioplasty
Abstract
Abstract: Introduction
This study aimed to determine the vertical and horizontal soft-tissue vs hard-tissue changes after isolated functional genioplasty and to revisit hard-tissue remodeling at the symphysis.
Methods
Seventy-five patients who underwent genioplasty as an isolated procedure at the end of their orthodontic treatment were divided into 3 groups on the basis of their age at surgery: <15 years (group 1), 15-18 years (group 2), and ≥19 years (group 3). Patients were evaluated at 3 time points: immediately before surgery (T1), immediately after surgery (T2), and 2 years after surgery (T3). In addition, 25 patients who did not accept genioplasty, were age-matched with group 1, and had a follow-up radiograph 2 years after the end of their orthodontic treatment were used as a control group.
Results
From T2 to T3, group 1 showed less forward horizontal hard-tissue and soft-tissue changes at pogonion (Pg) than the control group; however, no difference was noted for vertical changes at Me & Me'. From T1 to T3, the horizontal hard-tissue and soft-tissue changes at Pg were 6.39 mm and 6.72 mm, respectively, for surgical groups. Vertical hard-tissue change at menton (Me) showed a reduction of 1.63 mm (95% confidence interval [CI], −3.37 to 0.11) and 3.89 mm (95% CI, −5.83 to −1.95) in nongrowing female and male patients, respectively. The vertical soft-tissue change reduction was similar for nongrowing male and female patients (1.7 mm [95% CI, −2.96 to −0.45]). Soft-tissue thickness change at Pg (0.33 mm) was not significant. In contrast, a small but significant increase in soft-tissue thickness was noted at Me (0.54 mm). Linear regressions were calculated for all groups and allowed for predicting long-term soft-tissue changes (T3-T1) using the amount of surgical displacement (T2-T1).
Conclusions
The horizontal hard-tissue change was stable for nongrowing patients, and the horizontal soft-tissue change was 92% of hard-tissue. Vertical soft-tissue change is less predictable. Variation of soft-tissue thickness after genioplasty can be explained by skeletal changes and the achievement of an unforced labial occlusion. These results support the functional and esthetic benefits of this surgery. Comparison with the control group showed that genioplasty does not change the growth pattern, and bone remodeling is likely to explain the difference noted at Pg.
... The variation results from the irregular shape of dental and skeletal structures and individual variations in thickness and tension of soft tissues. Orthodontic treatment directly changes the position of hard tissues such as teeth or bones, and subsequently affects the facial appearance which is important for psychosocial well-being and social acceptance [1]. ...
... None. 1 ...
Background
The determining effect of facial hard tissues on soft tissue morphology in orthodontic patients has yet to be explained. The aim of this study was to clarify the hard-soft tissue relationships of the lower 1/3 of the face in skeletal Class II-hyperdivergent patients compared with those in Class I-normodivergent patients using network analysis.
Methods
Fifty-two adult patients (42 females, 10 males; age, 26.58 ± 5.80 years) were divided into two groups: Group 1, 25 subjects, skeletal Class I normodivergent pattern with straight profile; Group 2, 27 subjects, skeletal Class II hyperdivergent pattern with convex profile. Pretreatment cone-beam computed tomography and three-dimensional facial scans were taken and superimposed, on which landmarks were identified manually, and their coordinate values were used for network analysis.
Results
(1) In sagittal direction, Group 2 correlations were generally weaker than Group 1. In both the vertical and sagittal directions of Group 1, the most influential hard tissue landmarks to soft tissues were located between the level of cemento-enamel junction of upper teeth and root apex of lower teeth. In Group 2, the hard tissue landmarks with the greatest influence in vertical direction were distributed more forward and downward than in Group 1. (2) In Group 1, all the correlations for vertical-hard tissue to sagittal-soft tissue position and sagittal-hard tissue to vertical-soft tissue position were positive. However, Group 2 correlations between vertical-hard tissue and sagittal-soft tissue positions were mostly negative. Between sagittal-hard tissue and vertical-soft tissue positions, Group 2 correlations were negative for mandible, and were positive for maxilla and teeth.
Conclusion
Compared with Class I normodivergent patients with straight profile, Class II hyperdivergent patients with convex profile had more variations in soft tissue morphology in sagittal direction. In vertical direction, the most relevant hard tissue landmarks on which soft tissue predictions should be based were distributed more forward and downward in Class II hyperdivergent patients with convex profile. Class II hyperdivergent pattern with convex profile was an imbalanced phenotype concerning sagittal and vertical positions of maxillofacial hard and soft tissues.
... After removing duplicates, 287 articles were selected for review by two independent reviewers. Thirty-eight articles were found to be eligible for full-text assessment, out of which 31 articles were further rejected due to the use of additional surgical procedures apart from genioplasty or an insufficient follow-up period of less than six months, and seven articles were included in this review ( Figure 1) [1,5,[8][9][10][11][12]. ...
... Five studies reported up-to-date data regarding hard and soft tissue relapse at the pogonion in the horizontal and vertical directions at six months or more of the post-treatment follow-up period [1,5,8,10,12]. The average horizontal surgical advancement at hard tissue pogonion was 7.04 mm with a relapse of 0.69 mm after six months post-treatment. ...
The chin is a crucial component of facial aesthetics, and 20% of craniofacial problems require repair of the chin size, shape, and position. Genioplasty is used to treat irregularities in all three planes of the chin. Specific hard and soft tissue relapses following various genioplasty techniques have not been adequately studied in the literature to date. The purpose of this scoping review was to investigate the stability of hard and soft tissue changes achieved by different genioplasty procedures, six months after the procedure. A literature search was performed on PubMed, Web of Science, Embase, Wiley Online, Scopus, Google Scholar, Science Direct, and Cochrane databases from January 1, 2011 to October 31, 2022. Prospective and retrospective cohorts, case-control studies, observational studies, and randomized control trials, with at least 10 patients, which were written in English and evaluated the stability of different genioplasty procedures, with a follow-up period of at least six months were included. The manual and electronic search yielded 523 articles, and after complete screening, seven articles were selected (five with advancement genioplasty and two with reduction genioplasty) that met the eligibility criteria for review. The patients undergoing reduction genioplasty had a mean age of 24.15 years, compared to 20.5 years for augmentation genioplasty. The average follow-up period was 18.64 months for augmentation genioplasty and 10.5 months for reduction genioplasty technique. The relapse was assessed at pogonion, and it was noted that the average surgical advancement at hard tissue pogonion was 7.04 mm with a relapse of 0.69 mm after six months post-treatment. The average vertical movement of the hard tissue pogonion was 1.8 mm with a relapse of 0.74 mm. The average reduction at hard tissue pogonion was 3.2 mm in the vertical direction with a relapse of 0.2 mm and 0.8 mm reduction in soft tissue pogonion with a relapse of 0.3 mm. The soft to hard tissue ratio mentioned in the different studies ranged from 0.89 to 0.97. Both reduction and augmentation genioplasty are stable and reliable for altering the chin position for aesthetic purposes. The recommended mode of fixation is rigid fixation.
... However, no landmarks related to the chin showed statistically significant changes. This might be because of the hard-tissue vertical reduction at the chin after genioplasty, which was consistent with the results www.nature.com/scientificreports/ of Sylvain Chamberland, who reported that vertical soft-tissue change of chin points was less predictable after isolated functional genioplasty 5 . ...
This study aimed to study 3-dimensional (3D) changes of hard and soft tissues of skeletal class II patients after 2-jaw surgery and genioplasty. 32 adult patients diagnosed with mandibular hypoplasia who underwent 2-jaw surgery of maxillary impaction, mandibular advancement and genioplasty were enrolled. Cone-beam computed tomography and 3D stereophotogrammetry was conducted 1 week before and 6 months after surgery. Dolphin imaging software was used to establish a 3D digitizing model and 3D measurement system. Paired t-test was performed to compare the values before and after surgery. Pearson’s correlation test assessed the degree of correlations between hard and soft tissue change. The mean impaction of the maxilla was 2.600 ± 3.088 mm at A. The mean advancement of the mandible was 7.806 ± 2.647 mm at B. There was a significant upward and forward movement for most landmarks of the nose and lip, while a significant decrease in nasal tip height (lateral view), upper lip height, and upper and lower vermilion height. The nose's width was significantly increased. For maxillary, Sn, Ac-r, Ac-l, and Ls demonstrated a significant correlation with A and U1 in the anteroposterior axis. However, there were no significant correlations among them in the vertical axis. For mandibular, Li demonstrated a significant correlation with L1 in the anteroposterior axis specifically for the mandible. Notably, correlations between the landmarks of the chin's hard and soft tissues were observed across all axes. The utilization of 3-D analysis facilitated a quantitative comprehension of both hard and soft tissues, thereby furnishing valuable insights for the strategic formulation of orthognathic treatment plans targeting patients with skeletal class II conditions.
... There are various studies reporting the effects of advancement genioplasty in terms of skeletal and soft-tissues changes (12)(13)(14)(15). Most of these studies conclude that there is a linear relationship between changes in bone and in soft tissues in both horizontal and vertical movements (16). However, to the best of our knowledge, no study has reported on the effects of functional genioplasty on the alveolar bone adjacent to the mandibular incisors. ...
Introduction:
- Functional genioplasty aims to achieve lip competence at rest and reduces lip pressure against the mandibular incisors. The purpose of this study was to describe the radiographic changes in alveolar bone of the mandibular incisors after functional genioplasty.
Materials and methods:
- Cone beam CT images from 36 patients were compared between immediate (T0) and delayed postoperative period (T1). The mean time to complete the second imaging was 10.9 ± 4.7 months. Dental and bone parameters were assessed: the vestibular bone height (BH), the bone thickness (BT) with regard to the apex of the central incisor (BT2) and at equidistance between the cementoenamel junction and the dental apex (BT1). The existence of fenestrations, the apical-root resorption and the incisor-mandibular plane angle (IMPA) were also collected.
Results:
- No significant change occurred in the BH. BT was improved of a mean 47.9% and 53.6% at the BT1 level on #31 and #41, respectively (p1=0.01 and p2=0.02, respectively); and of 53.0% at the level of the apex of both mandibular central incisors (p1=0.003 on #31 and p2=0.009 on #41). No difference in the number of fenestrations was observed between T0 and T1. A significant decrease in the root length on both mandibular incisors was observed on the delayed CBCT (from 21.96 ± 1.35 to 21.68 ± 1.32 mm for #31, p=0.0007; from 22.26 ± 1.66 to 21.96 ± 1.48 mm for #41, p=0.002). Finally, the IMPA remained stable between the two examinations with a mean 106.1 ± 7.38° vs 105.8 ± 6.51° (p=0.38).
Conclusion:
- Functional genioplasty favours the alveolar bone formation of the mandibular central incisors, probably by direct bone grafting, but also by the relaxation of the perioral and chin musculature.
Traditional horizontal osteotomies for small and short chins often yield suboptimal results due to limited bone advancement, resulting in deep labiomental folds and heightened bone resorption risks. This study investigates the effectiveness of an innovative inverted V-shaped osteotomy technique in enhancing esthetic outcomes for patients with such chin concerns. Thirty-eight patients who underwent inverted V-shaped osteotomy for recessed chins between January 2018 and June 2022 were included. Excluding cases involving simultaneous mandibular contouring surgery, patients were followed up for a median duration of 1.2±0.5 years. Preoperation and postoperation soft tissue pogonion (Pg’) and labiomental fold depth (LMF) changes were measured. IBM SPSS (version 27.0) was used for statistical analysis, with significance defined as P <0.05. Patient satisfaction was assessed using a visual analog scale. Successful advancement genioplasty was performed on all patients without any severe complications. The average change in soft tissue pogonion (Pg’) measured 6.2 (1.9) mm, and the mean alteration in labiomental depth was 0.42 (0.4) mm. The procedure achieved a bone to soft tissue movement ratio of 1:0.96. Patient satisfaction was notably high, with a mean VAS score of 8.7. An inverted V-shaped osteotomy enables greater bone advancement for small and short chins, leading to improved esthetic outcomes and offering a mechanically advantageous condition for bone segments.
Objective:
To evaluate the role of age as a moderator of bone regeneration patterns and symphysis remodeling after genioplasty.
Method:
Fifty-four patients who underwent genioplasty at the end of their orthodontic treatment were divided into three age groups: younger than 15 years at the time of surgery (group 1), 15 to 19 years (group 2), and 20 years or older (group 3). Twenty-three patients who did not accept genioplasty and had a follow-up radiograph 2 years after the end of their orthodontic treatment were used as a control group. Patients were evaluated at three time points: immediate preoperative (T1), immediate postoperative (T2,) and 2 years postsurgery (T3).
Results:
The mean genial advancement at surgery was similar for the three age groups, but the extent of remodeling around the repositioned chin was greater in group 1, less in group 2, and still less in group 3. Symphysis thickness increased significantly during the 2-year postsurgery interval for the three groups, and this increase was significantly greater in group 1 than in group 3. Remodeling above and behind the repositioned chin also was greater in the younger patients. This was related to greater vertical growth of the dentoalveolar process in the younger patients. There was no evidence of a deleterious effect on mandibular growth.
Conclusion:
The outcomes of forward-upward genioplasty include increased symphysis thickness, bone apposition above B point, and remodeling at the inferior border. When indications for this type of genioplasty are recognized, early surgical correction (before age 15) produces a better outcome in terms of bone remodeling.
Genioplasty is often performed to esthetically improve patient's profiles in the lower facial third. Many factors account for the variability in soft tissue response like dissection technique, magnitude and direction of movement and stability of the genial segment. Optimum treatment planning thus requires an understanding of the soft tissue response to various genial procedures.
To determine the stability, ratio of hard and soft tissues and changes in the lower facial profile after advancement genioplasty.
Ten patients were evaluated cephalometrically for the soft tissue changes in relation to hard tissues after advancement genioplasty. Pre operative, immediate post operative and 6 months post operative lateral cephalogram were taken. Pre operative tracings were superimposed with post operative cephalograms to produce a composite tracing. Changes in the osseous tissues are assessed and related to the net changes in the soft tissues.
The ratio of horizontal changes of osseous to soft tissues was found to be 1:0.89. The mean resorption was 0.85 mm (10.7%). The vertical changes are minimal and non significant. There are significant changes in the soft tissue profile such as decrease in the soft tissue thickness, facial convexity angle, lower facial submental angle and increase in mentolabial sulcus depth.
The standard advancement genioplasty procedure by inferior osteotomy of the chin with broadest musculo-periosteal pedicle with rigid internal fixation was followed. The soft tissue response is almost equal to the bony movement. The stability of the hard tissues is good with minimum amount of resorption so as to achieve more predictable results.
Reliability coefficients often take the form of intraclass correlation coefficients. In this article, guidelines are given for choosing among 6 different forms of the intraclass correlation for reliability studies in which n targets are rated by k judges. Relevant to the choice of the coefficient are the appropriate statistical model for the reliability study and the applications to be made of the reliability results. Confidence intervals for each of the forms are reviewed. (23 ref) (PsycINFO Database Record (c) 2006 APA, all rights reserved).
A hierarchy of stability exists among the types of surgical movements that are possible with orthognathic surgery. This report updates the hierarchy, focusing on comparison of the stability of procedures when rigid fixation is used. Two procedures not previously placed in the hierarchy now are included: correction of asymmetry is stable with rigid fixation and repositioning of the chin also is very stable. During the first post-surgical year, surgical movements in patients treated for Class II/long face problems tend to be more stable than those treated for Class III problems. Clinically relevant changes (more than 2 mm) occur in a surprisingly large percentage of orthognathic surgery patients from one to five years post-treatment, after surgical healing is complete. During the first post-surgical year, patients treated for Class II/long face problems are more stable than those treated for Class III problems; from one to five years post-treatment, some patients in both groups experience skeletal change, but the Class III patients then are more stable than the Class II/long face patients. Fewer patients exhibit long-term changes in the dental occlusion than skeletal changes, because the dentition usually adapts to the skeletal change.
Purpose
The aim of this review was to investigate the skeletal and soft tissue stability of isolated advancement genioplasty after more than 1 year, and to observe the influence of associated risk factors.
Methods
A literature search was performed on PubMed, Web of Science, Embase, ScienceDirect, and Cochrane. Only studies with at least 10 patients who underwent an isolated advancement genioplasty, and with a follow-up period of at least 1 year, were included.
Results
Of the 2224 records initially identified, eight articles met the eligibility criteria. The mean age of the total study population was 23 years and ranged from 19.1 to 26.5 years in the individual studies. The average surgical advancement at pogonion was 8.2 mm and ranged from 6.2 to 11.7 mm in the individual studies. After 1 year, the horizontal hard tissue relapse at the level of pogonion varied from 0.1 to 2.1 mm. In two studies, this was reported as statistically significant. Regarding the soft tissue, the horizontal relapse varied from 0.3 to 2.9 mm, which was also considered statistically significant in two studies.
Conclusion
Isolated advancement genioplasty was found to be a predictable and stable orthognathic procedure in the sagittal plane at both soft and hard tissue levels. The amount of relapse was not associated with the fixation method or with the amount of surgical advancement.
Objectives:
To develop a prediction algorithm for soft tissue changes after orthognathic surgery that would result in accurate predictions (1) regardless of types or complexity of operations and (2) with a minimum number of input variables.
Materials and methods:
The subjects consisted of 318 patients who had undergone the surgical correction of Class II or Class III malocclusions. Two multivariate methods-the partial least squares (PLS) and the sparse partial least squares (SPLS) methods-were used to construct prediction equations. While the PLS prediction model included 232 input variables, the SPLS method included a reduced number of variables generated by a handicapping algorithm via the sparsity control. The accuracy between the PLS and SPLS models was compared.
Results:
There were no significant differences in prediction accuracy depending on surgical movements, the sex of the subjects, or additional surgeries. The predictive performance with a reduced set of 34 input variables chosen using the SPLS method was statistically indistinguishable from the full set of variables with the original PLS prediction model.
Conclusions:
The prediction method proposed in the present study was accurate for a wide range of orthognathic surgeries. A reduced set of input variables could be selected through the SPLS method while simultaneously maintaining a prediction level that was as accurate as that of the original PLS prediction model.
This retrospective study was conducted to determine the difference in the cost of genioplasty according to the osseous fixation technique used.
A retrospective study among orthognathic surgery patients treated over a 54-month period ending in June 30, 2011 was conducted. Immediately post surgery, panoramic and cephalometric radiographs of these patients were assessed to determine the presence of genioplasty procedure and the type of fixation used. The cost of the actual fixation used by the surgeons was compared with that which the cost would have been had the surgeons used the criteria described in the hypotheses, for plate and screws fixation when genioplasty is performed.
A review of 1,498 orthognathic surgery patients revealed that 473 of these patients underwent genioplasty. Out of 473 patients, 425 had genioplasty to either advance and-or superiorly reposition the chin. Of these, 230 had wire osteosynthesis and 243 had some form of rigid fixation. The unit cost of fixation for genioplasty when wire osteosynthesis is used is less than C542.00. All 230 patients in whom wire osteosynthesis was used demonstrated stable fixation of the bony parts and no immediate postsurgical adjustment was required in any patient.
For patients requiring genioplasty to advance and-or superiorly reposition the chin, it is possible to use wire osteosynthesis to achieve accurate and stable fixation while reducing the fixation cost by more than C$500.00 per case. The surgeon should include cost considerations in the selection of treatment methods.
Objective:
To propose a better statistical method of predicting postsurgery soft tissue response in Class II patients.
Materials and methods:
The subjects comprise 80 patients who had undergone surgical correction of severe Class II malocclusions. Using 228 predictor and 64 soft tissue response variables, we applied two multivariate methods of forming prediction equations, the conventional ordinary least squares (OLS) method and the partial least squares (PLS) method. After fitting the equation, the bias and a mean absolute prediction error were calculated. To evaluate the predictive performance of the prediction equations, a leave-one-out cross-validation method was used.
Results:
The multivariate PLS method provided a significantly more accurate prediction than the conventional OLS method.
Conclusion:
The multivariate PLS method was more satisfactory than the OLS method in accurately predicting the soft tissue profile change after surgical correction of severe Class II malocclusions.
INTRODUCTION: Sequential stages in the development of the hand, wrist, and cervical vertebrae commonly are used to assess maturation and predict the timing of the adolescent growth spurt. This approach is predicated on the idea that forecasts based on skeletal age must, of necessity, be superior to those based on chronologic age. This study was undertaken to test this reasonable, albeit largely unproved, assumption in a large, longitudinal sample. METHODS: Serial records of 100 children (50 girls, 50 boys) were chosen from the files of the Bolton-Brush Growth Study Center in Cleveland, Ohio. The 100 series were 6 to 11 years in length, a span that was designed to encompass the onset and the peak of the adolescent facial growth spurt in each subject. Five linear cephalometric measurements (S-Na, Na-Me, PNS-A, S-Go, Go-Pog) were summed to characterize general facial size; a sixth (Co-Gn) was used to assess mandibular length. In all, 864 cephalograms were traced and analyzed. For most years, chronologic age, height, and hand-wrist films were available, thereby permitting various alternative methods of maturational assessment and prediction to be tested. The hand-wrist and the cervical vertebrae films for each time point were staged. Yearly increments of growth for stature, face, and mandible were calculated and plotted against chronologic age. For each subject, the actual age at onset and peak for stature and facial and mandibular size served as the gold standards against which key ages inferred from other methods could be compared. RESULTS: On average, the onset of the pubertal growth spurts in height, facial size, and mandibular length occurred in girls at 9.3, 9.8, and 9.5 years, respectively. The difference in timing between height and facial size growth spurts was statistically significant. In boys, the onset for height, facial size, and mandibular length occurred more or less simultaneously at 11.9, 12.0, and 11.9 years, respectively. In girls, the peak of the growth spurt in height, facial size, and mandibular length occurred at 10.9, 11.5, and 11.5 years. Height peaked significantly earlier than both facial size and mandibular length. In boys, the peak in height occurred slightly (but statistically significantly) earlier than did the peaks in the face and mandible: 14.0, 14.4, and 14.3 years. Based on rankings, the hand-wrist stages provided the best indication (lowest root mean squared error) that maturation had advanced to the peak velocity stage. Chronologic age, however, was nearly as good, whereas the vertebral stages were consistently the worst. Errors from the use of statural onset to predict the peak of the pubertal growth spurt in height, facial size, and mandibular length were uniformly lower than for predictions based on the cervical vertebrae. Chronologic age, especially in boys, was a close second. CONCLUSIONS: The common assumption that onset and peak occur at ages 12 and 14 years in boys and 10 and 12 years in girls seems correct for boys, but it is 6 months to 1 year late for girls. As an index of maturation, hand-wrist skeletal ages appear to offer the best indication that peak growth velocity has been reached. Of the methods tested here for the prediction of the timing of peak velocity, statural onset had the lowest errors. Although mean chronologic ages were nearly as good, stature can be measured repeatedly and thus might lead to improved prediction of the timing of the adolescent growth spurt.
Lip pressures before and after orthognathic surgery were studied to evaluate the relationship between posttreatment soft-tissue adaptation and incisor stability. After all surgical procedures, physiologic adaptation resulted in the maintenance of pressures during speech and swallowing. When the maxilla was advanced by LeFort I osteotomy, a significant decrease in resting pressure of the upper lip was observed instead of the expected increase and incisor stability did not seem related to soft-tissue influences. When the mandible was advanced by sagittal split osteotomy, resting pressure did not increase as expected-, but there was a tendency for incisors to become more upright after fixation release, perhaps as a rebound from labial tipping in fixation. When soft tissues were relaxed as the mandible rotated forward following superior repositioning of the maxilia, resting pressures decreased and lower incisors tended to be positioned forward as predicted by equilibrium theory.
This retrospective study evaluated the skeletal and soft tissue facial profile changes as well as the predictability and the short-term stability of the soft-tissue response to advancement genioplasty in Class I dental arch relationship patients. The study included 14 adult patients who presented a Class I dental arch but a Class II skeletal arch relationship and underwent advancement genioplasty exclusively. Lateral cephalograms taken immediately preoperatively (T1), immediately postoperatively (T2) and 1 year postoperatively (T3) were analysed. The hard tissue pogonion was sagittally advanced by an average of 7.9 mm (p<0.001) (T1-T2). The soft tissue chin followed the sagittal skeletal chin movement and exceeded chin advancement due to the initial soft tissue swelling. In the vertical dimension, the skeletal chin moved 3.0mm (p<0.01) upwards whilst the soft tissue chin moved only 2.1mm upwards (p<0.01). All profile convexity angles increased significantly (p<0.001), implying that the profile was straightened by the advancement of the chin. In the short term, advancement genioplasty was a predictable and stable procedure for chin correction. A ratio of 1:1 may be used to predict the sagittal soft tissue to bony movements for the period from before to 1 year after surgery.
Changes in facial esthetics after orthognathic surgery should be predictable if the results are to be satisfactory. The skeletal elements are moved in a planned and controlled manner, but the soft tissue drape is not as precisely managed. This study was on 31 patients who had undergone a mandibular advancement by means of a sagittal split osteotomy, 17 of whom had also received an advancement genioplasty and 6 received a maxillary impaction. The results showed a consistent 1:1 ratio of soft to hard tissue advancement at pogonion and B point, and that predictions could be accurate in both anteroposterior and vertical directions. When a genioplasty was added to the advancement, however, the results were much less consistent. The mean ratio was 0.9:1 of soft tissue to skeletal movement at pogonion, but the average difference between hard and soft tissue movement was +/- 2.6 mm. Thus the prediction of anteroposterior soft tissue changes was quite inaccurate. Changes in the vertical dimension were also more marked in the genioplasty group. The lower lip also showed a variable response, particularly in the genioplasty group, where the mean ratio was 0.5 mm lip advancement per 1.0 mm skeletal change, but again a range of 4.0 mm in either direction. There were no meaningful changes 1 year after surgery.
The form of the anterior mandible in 45 patients was assessed before, immediately after, and 1 year after genioplasty. A specific, consistent pattern of bone apposition and resorption was observed after advancement genioplasty. A consistent but inverse apposition-resorption pattern was observed after reduction genioplasty. In view of the observed pattern of bony change, it is recommended that fixation devices for genioplasty be placed in areas of future bone deposition.
Large advancement genioplasties were performed in 10 patients (mean advancement, 11.7 mm) by horizontal osteotomy of the inferior border of the mandible, with preservation of a musculoperiosteal pedicle to the advanced genial segment. Preoperative, immediate postoperative, and long-term follow-up lateral cephalometric radiographs were retrospectively analyzed to evaluate the osseous and soft-tissue changes of the chin. After a mean follow-up period of 15 months, 76% of the initial advancement was preserved, representing 24% osseous resorption. The enveloping soft tissues of the chin followed the bony movement in a ratio of 1:0.88. Horizontal osteotomy of the inferior border of the mandible was a relatively stable procedure when used for large chin advancements. The broadcast possible musculoperiosteal pedicle should remain attached to the advanced genial segment to minimize osseous resorption and to achieve more predictable soft-tissue changes.
This study examined the immediate and postsurgical changes in the hard and soft tissues of the chin after advancement genioplasty by means of oblique osteotomy of the mandibular symphysis. Twenty-three patients who had undergone this procedure were evaluated cephalometrically for up to 6 months after surgery. The results indicated that the position of the genial segment is stable after advancement. There was a good correlation between the amount of hard versus soft tissue change with surgery in the horizontal direction but a poor correlation in the vertical plane. There was, however, a great amount of variability from one patient to the next in most of the variables examined. Follow-up results were generally very stable.
Twenty-three patients who had undergone advancement genioplasty were evaluated an average of over 3 years postsurgically for bone and soft tissue stability. Traced serial cephalometric radiographs revealed no discernible bony remodeling from gnathion to the menton region. Six cases showed minor posterior shifting of the inferior border segment. Although good correlation existed between hard and soft tissue movement, minor soft tissue variation occurred without obvious correlation to bony remodeling.
The functional genioplasty is an osteotomy-ostectomy of the anterior mandible which reduces excessive lower anterior facial height to 55% of the total anterior facial height. The procedure is indicated particularly when one factor contributing to the long-face syndrome is vertical excess of the anterior mandible. The surgical technique involves creation of a tenon and mortise which not only preserves the insertions of both the labiomental muscles and at least some of the suprahyoid muscles but also improves the stability of transosseous fixation. Superior repositioning and advancement of the chin and myocutaneous structures produce both functional and esthetic benefits for the patient.
When a large chin advancement is performed and a broad musculo-periosteal pedicle is preserved, excessive stretching of the suprahyoid musculature may occur, leading to instability or resorption of the advanced genial segment. The present study was designed to evaluate long-term osseous and soft tissue changes after large advancement genioplasties (greater than 10 mm), achieved by horizontal osteotomy of the inferior border of the mandible, with preservation of a musculo-periosteal pedicle to the advanced genial segment. Bone remodeling and the inherent soft tissue changes were radiographically assessed in a long-term follow-up period (mean = 26.8 months), with attention to observe progressive osseous changes. Despite the observed 17% bone resorption, the enveloping soft tissues of the chin followed the bony movement in a ratio of 1:0.83. Osseous resorption was not progressive, and the soft tissue changes remained unaltered. A broad musculo-periosteal pedicle consistent with the surgical objective should remain attached to the advanced genial segment to minimize osseous resorption and achieve more predictable soft tissue changes. We emphasize the need for a longer follow-up period (25-30 years) to determine the effect of the stabilization devices and osseous remodeling, specially in younger patients.
This study investigated the relationship of age at surgery and type of fixation to the pattern and extent of bone remodeling associated with inferior border osteotomy for chin augmentation.
Four groups of patients with similar chin advancement were established by age at the time of surgery: younger than 15, 15 to 19, 20 to 24, and older than 39 years. Cephalometric radiographs for immediate preoperative, immediate postoperative, and at least 9 months postoperative times were traced, digitized, and superimposed.
The pattern of osseous remodeling was similar for all age-groups. This consisted of resorption of the superior-buccal aspect of the distal segment, bone apposition on the buccal surface of the proximal segment, and modest resorption at pogonion (mean change, 1 mm or less). There was no significant difference in stability of the chin advancement between wire and rigid (screw) fixation. There was a marked difference in the symphysis thickness regeneration of the youngest group (92% of the original symphysis thickness) compared with the rest of the groups (< or =66%, P < .001).
Minimal remodeling at pogonion occurs in all age-groups with both wire and rigid fixation. Regeneration of symphysis thickness is much more complete in patients younger than 15 years at the time of surgery. This is potentially important for early treatment of severe chin deficiency, because it permits additional advancement of the chin later in life, if necessary.
The incision, dissection, osteotomy design and fixation are important technical considerations when performing a genioplasty. The purpose of this study was to describe an extended genioplasty technique and to evaluate stability of position, form, surface area of the chin and incidence of postoperative sensory deficit. Records of 15 consecutive adult patients who underwent the extended genioplasty procedure were reviewed. The technique included incision in the labial vestibule from 2nd premolar to 2nd premolar, dissection, mobilization and retraction of the mental nerves, osteotomy parallel to the occlusal plane extending proximally to the antegonial notch and rigid fixation. Lateral cephalograms pre- and postoperatively and at the latest follow-up (> 6 months) were analyzed by linear and computer morphometric measurements to evaluate changes in position, shape and surface area of the chin. Neurosensory data from examination or questionnaire were recorded. Immediately postoperatively (T1), mean advancement in the sagittal plane was +8.7 mm and increase in surface area was +1.1 cm2. At the end of follow-up (T2), there were no significant changes (T2-T1) in chin position or surface area. Inferior border form was rated as smooth in all cases. Neurosensory evaluation revealed that 12/12 patients evaluated had functional sensory return at T2.
The purpose of this study was to assess hard and soft tissue stability 12 months after advancement genioplasty.
This is a retrospective study of 20 patients who underwent either advancement genioplasty alone (n = 11) or in combination with bilateral sagittal split osteotomy for mandibular advancement (n = 9). Lateral cephalometric radiographs were traced and immediate postoperative changes and 12-month postoperative changes were defined. The relapse rate for the pogonion, the soft tissue pogonion, and the soft tissue B point (Bs) were evaluated. The results were compared for combined mandibular advancement plus genioplasty versus genioplasty alone. Relapse rates were also correlated with the amount of advancement. All patients were treated with rigid internal fixation.
After 12 months, the pogonion, the soft tissue pogonion, and the soft tissue B point had a mean relapse rate of -0.38 mm, -1.2 mm, and -1.5 mm (negative value indicates a relapse, and a positive value indicates prolapse), respectively, which was not significant at probability values of.45,.069, and.054, respectively. Relapse was not statistically related to the amount of advancement. There was no significant difference between the relapse rate for genioplasty alone versus combined bilateral sagittal split osteotomy and genioplasty, even with different amounts of advancement.
Advancement genioplasty is an important and reliable technique for the esthetic treatment of the lower facial skeleton. The results indicate that there is no significant relapse after genioplasty and bilateral sagittal split osteotomy or genioplasty alone after 12 months when rigid internal fixation is used. The changes were minimal and hard to detect clinically. Genioplasty, with or without mandibular advancement, is a stable surgical procedure when used in conjunction with rigid internal fixation.
This study compares vertical and horizontal profile changes of the lower lip and chin after genioplasty with or without precise reattachment of the mentalis muscle.
Ten patients in whom the mentalis muscle was isolated, identified, marked, and precisely reapproximated comprised the study group. Eleven patients treated without precise reattachment of the mentalis comprised the control group. Preoperative (3 to 6 days before the surgery) and postoperative (6 months after surgery) lateral cephalograms were analyzed to assess the horizontal and vertical soft tissue changes of the lower lip and chin area.
All the significant changes in the present study were noted in the vertical parameters. In most of the study group, the length of the lower lip was either maintained or increased. In the control group, the lower lip length was either preserved or decreased. The mean vertical difference between the 2 groups was nearly 6 mm. Consequently, the study group displayed the same or less of the lower incisors postsurgery compared with the original presurgery exposure in the rest position. The opposite was true for the control group, in which the exposure of the lower incisor crowns at rest increased. Similar changes were noticed in the distance from the vermilion to the reference plane. The vertical position of the soft tissue supramentale remained unchanged in the study group, whereas in the control group the soft tissue supramentale was located in an inferior position (mean = 2.14 mm). The clinical expression of this phenomena is chin ptosis.
Precise reattachment of the mentalis muscle during an intraoral surgical approach produces a superior result.
The purposes of this retrospective study were to examine the multidimensional nature of soft tissue changes associated with mandibular advancement and genioplasty and to develop predictive models. Longitudinal lateral cephalograms of 62 nongrowing patients (27 men and 35 women) were taken in centric relation with the lips in repose within 4 weeks before surgery and at least 6 months postoperatively (median postsurgical duration was 11 months). The mandibular incisor and pogonion were advanced surgically approximately 6 mm and 11 mm, respectively. The lower lip lengthened slightly (2.5 +/- 3.8 mm), and its surface contour straightened because of thinning at labrale inferior (-2.8 +/- 2.0 mm); there was a slight thickening at the labiomental fold (1.0 +/- 2.3 mm) and a slight thinning at soft tissue pogonion (-0.8 +/- 2.2 mm). Multiple regression models (explaining from 80% to 94% and 66% to 82% of the variation for horizontal and vertical movements, respectively) showed that soft tissue response to advancement surgery depended on pretreatment tissue thickness, horizontal skeletal movement, vertical skeletal movement, and the position of the maxillary incisors. Similar amounts of variation were explained when the models were applied to an independent validation sample of 15 subjects. It was concluded that lower lip and chin response to mandibular advancement and genioplasty is multifactorial but can be accurately and reliably predicted.
The purpose of this study was to follow the covariation of hard and soft tissue changes in Class II malocclusion subjects who received a bilateral sagittal split osteotomy. The subjects were randomized to receive wire or rigid fixation after the surgery. Subjects in the rigid group (n = 78) received 2-mm bicortical position screws, and those in the wire group (n = 49) received inferior border wires and 6 weeks of skeletal intermaxillary fixation with 24-gauge wires. Additionally, some subjects received genioplasty in both the rigid (n = 35) and the wire groups (n = 24). Soft and hard tissue profile changes were obtained from cephalometric films immediately before surgery and at various times up to 5 years postsurgery. Soft and hard tissue profile changes were referenced to a cranial-base X-Y coordinate system. Horizontal changes in mandibular incisor, lower lip, B-point, soft tissue B-point, pogonion, and soft tissue pogonion were calculated at each time. There was considerable skeletal relapse in the wire fixation group. Bivariate correlations and ratios between the hard and soft tissue changes were calculated for each time period. Hard to soft tissue correlations were the highest at the earlier times, although the ratios varied among the 4 groups. These results provide a solid basis for both short-term and long-term prediction.
The objective of this study was to answer the following questions: Are profiles of Class I patients perceived as more attractive than profiles of Class II or Class III patients in Germany today? How pronounced must a skeletal malocclusion be to be perceived as less attractive? Are there differences in perception between dentists and laypersons?
For the present study we examined seven patients with skeletal Class I, orthognathic maxillae and mandibles, and straight average faces (ideal biometric face as defined by A. M. Schwarz). Using the Onyx Ceph software, their profile lines were modified to reflect three different Class II profile variants and three different Class III profile variants. The 49 profiles thus obtained were assigned to two groups. Group 1 comprised the seven straight average faces and the first part of the retrognathic and prognathic profile variants. Group 2 comprised the same seven straight average faces and the remaining retrognathic and prognathic profile variants. Both groups of faces were scored by 130 laypersons and 126 dentists.
Both groups of observers perceived the seven straight average faces similarly both in the first and second (subsequent) scoring rounds. The straight average face was perceived as most attractive by laypersons (mean, 5.48; 95% confidence interval (CI:) 5.33-5.60) and dentists (mean, 5.44; 95% CI, 5.28-5.50) alike, followed by the mildest variant of the retrognathic face (laypersons, mean, 4.85; 95% CI, 4.68-5.01; dentists, mean, 4.98; 95% CI, 4.81-5.10). Dentists differentiated more clearly by degree of skeletal malocclusion than did laypersons. Both groups alike perceived the extreme variant of the prognathic and retrognathic profile lines as the least attractive. Grouping the subjects by gender yielded only minor differences in perception.
The straight average face is perceived as most attractive by representative German populations today. Dentists make clearer gradual distinctions in their perceptions than do laypersons.
To describe a new method for measuring facial swelling following orthognathic surgery using a 3D laser-scanning device.
Prospective clinical trial. Setting and Sample Population -- University Dental Hospital, Wales College of Medicine, Biology Life and Health Sciences. Three subjects requiring bi-maxillary orthognathic surgery were recruited for the study.
Laser-scanned images of the subjects were obtained under a reproducible and controlled environment with two Minolta Vivid 900 (Osaka, Japan) optical laser-scanning devices assembled as a stereo-pair. A set of left and right scanned images was taken for each subject and each scan took an average of 2.5 s. 3D laser scans were recorded over six time periods (T1 -- pre-surgical scan, postoperatively: T2 -- 1 day, T3 -- 1 week, T4 -- 1 month, T5 -- 3 months and T6 -- 6 months).
Facial scans from different time periods were overlaid onto the baseline (T6) facial scan to determine the reduction and changes in swelling following orthognathic surgery.
The results showed that swelling could be accurately quantified following surgery. Furthermore, there was a significant reduction in the amount of swelling 1 month postoperatively. Furthermore, the facial morphology returned to approximately 90% of the baseline facial scan at 3 months.
The 3D laser-scanning device and the method described was a reliable and accurate measure of facial swelling following surgery.
The objectives of this cephalometric study were to assess the skeletal stability of advancement genioplasty 3 years after surgery and to evaluate the predictability of soft-tissue changes.
The subjects comprised 21 consecutive patients who had no additional orthognathic surgical procedures. Lateral cephalograms were taken at 5 times: immediately preoperative, immediately postoperative, 6 months postoperative, and 1 and 3 years postoperative.
Mean surgical advancement at pogonion was 8.4 mm. Three years after surgery, mean relapse at pogonion was 8% of the surgical advancement. Part of this change was most likely due to bone remodeling. No patient demonstrated a clinically significant postoperative change at pogonion. The soft tissue of the chin was found to follow bony movement in a ratio of 0.9:1. Great individual variability was observed. The mentolabial fold depth increased as a result of the treatment. Effects of advancement genioplasty on the lips were small.
A prediction ratio based on long-term skeletal changes is likely to generate an estimate that is more appropriate to present to the patient.
The reasons people consult the orthodontist are functional, prophylactic and esthetic in nature, which is why it is important to know (in justifying an intervention for esthetic reasons) what patients themselves find attractive, and whether German university graduates and non-graduates would evaluate the attractiveness of profile views of Class-I, -II and -III patients differently. We also were interested in identifying per group the degree of deviation (from a "normal" skeletal profile) from which the appraisers would judge that profile to be unattractive.
A total of five skeletal Class-I patients with straight-average faces (ideal biometric face as defined by A. M. Schwarz 1958) were transformed to reflect three Class-II profile variants and three Class-III profile variants with Onyx Ceph software. Out of the 35 profiles thus obtained we formed two groups of 20 each. Group 1 comprised the five straight-average (biometric) faces and six retrognathic and nine prognathic profile variants. Group 2 comprised the same five straight-average faces and the remaining retrognathic and prognathic profile variants. Both face groups were evaluated by 117 university graduates (65 men and 52 women) and 103 non-graduates (49 men and 54 women) between 23 and 41 years old. The participants were randomly assigned to the two groups. These volunteers were asked to rate the profiles along a scale of 0 (least attractive) to 10 (most attractive). The paper copies with the profiles were assessed in comparison to a single profile that had been classified with an average of 7.6 by ten orthodontists.
Both groups of observers perceived the five straight-average faces similarly in the first and second scoring rounds. The straight-average face was perceived as the most attractive by both the university graduates (mean: 5.37; 95% CI: 5.15-5.59) and non-graduates (mean: 5.71; 95% CI: 5.48-5.95), followed immediately by mildly and moderately retrognathic, as well as mildly prognathic profile lines. Both groups perceived extremely prognathic and retrognathic profile lines as the least attractive (mean value for graduates: 4.27; 95% CI: 4.05-4.49; for nongraduates: 4.83; 95% CI: 4.59-5.06), with the university graduates' ratings being significantly lower than those of the nongraduates. Grouping the subjects by gender yielded only minor differences in perception.
The straight-average face was perceived as being the most attractive by representative populations in Germany. On the whole, the university graduates were more critical in their ratings than non-graduates.
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- Budharapu
The search for truth: diagnosis
- Proffit
Five-year outcome and predictability of soft tissue profiles when wire or rigid fixation is used in mandibular advancement surgery
- Dolce
Segmental jaw surgery
- Proffit
Mommaerts MYA systematic review on soft-to-hard tissue ratios in orthognathic surgery part II: chin procedures
- San Miguel Moragas