To compare the archwires inserted during the final stages of the orthodontic treatment with the generated moments at 0.018- and 0.022-inch brackets.
Materials and methods:
The same bracket type, in terms of prescription, was evaluated in both slot dimensions. The brackets were bonded on two identical maxillary acrylic resin models, and each model was mounted on the orthodontic measurement and simulation system. Ten 0.017 × 0.025-inch TMA and ten 0.017 × 0.025-inch stainless steel archwires were evaluated in the 0.018-inch brackets. In the 0.022-inch brackets, ten 0.019 × 0.025-inch TMA and ten 0.019 × 0.025-inch stainless steel archwires were measured. A 15° buccal root torque (+15°) and then a 15° palatal root torque (-15°) were gradually applied to the right central incisor bracket, and the moments were recorded at these positions. A t-test was conducted to compare the generated moments between wires within the 0.018- and 0.022-inch bracket groups separately.
The 0.017 × 0.025-inch archwire in the 0.018-inch brackets generated mean moments of 9.25 Nmm and 14.2 Nmm for the TMA and stainless steel archwires, respectively. The measured moments in the 0.022-inch brackets with the 0.019 × 0.025-inch TMA and stainless steel archwires were 6.6 Nmm and 9.3 Nmm, respectively.
The 0.017 × 0.025-inch stainless steel and β-Ti archwires in the 0.018-inch slot generated higher moments than the 0.019 × 0.025-inch archwires because of lower torque play. This difference is exaggerated in steel archwires, in comparison with the β-Ti, because of differences in stiffness. The differences of maximum moments between the archwires of the same cross-section but different alloys were statistically significant at both slot dimensions.
To determine if there is a significant difference in the clinical outcomes of cases treated with 0.018-inch brackets vs 0.022-inch brackets according to the American Board of Orthodontics (ABO) Objective Grading System (OGS).
Treatment time and the ABO-OGS standards in alignment/rotations, marginal ridges, buccolingual inclination, overjet, occlusal relationships, occlusal contacts, interproximal contacts, and root angulations were used to compare clinical outcomes between a series of 828 consecutively completed orthodontic cases (2005-2008) treated in a university graduate orthodontic clinic with 0.018-inch- and 0.022-inch-slot brackets.
A two-sample t-test showed a significantly shorter treatment time and lower ABO-OGS score in four categories (alignment/rotations, marginal ridges, overjet, and root angulations), as well as lower total ABO-OGS total score, with the 0.018-inch brackets. The ANCOVA-adjusting for covariants of discrepancy index, age, gender, and treatment time-showed that the 0.018-inch brackets scored significantly lower than the 0.022-inch brackets in both the alignment/rotations category and total ABO-OGS score.
There were statistically, but not clinically, significant differences in treatment times and in total ABO-OGS scores in favor of 0.018-inch brackets as compared with the 0.022-inch brackets in a university graduate orthodontic clinic (2005-2008).
To assess the effectiveness of 0.2% chlorhexidine gluconate mouth rinse on Streptococcus mutans and lactobacilli in orthodontic patients with fixed appliances.
Twenty patients, aged 13-18, with fixed orthodontic appliances participated in the study. The levels of S mutans and lactobacilli in saliva samples were evaluated at four stages: at the beginning of the orthodontic treatment, at least 2 weeks after the bonding of brackets, 1 week after the introduction of 0.2% chlorhexidine gluconate mouth rinse, and at the fourth week. The changes in S mutans and lactobacilli levels were analyzed via Wilcoxon test.
Increases in bacterial levels of S mutans and lactobacilli were detected after the orthodontic appliances were bonded. A significant decrease in S mutans levels was observed 1 week after the introduction of chlorhexidine mouth rinse.
An 0.2% chlorhexidine gluconate mouth rinse decreased S mutans levels, but had no effect on lactobacilli levels.
To compare perceptions of dental aesthetics of Class III and anterior open bite (AOB) malocclusions between 10- to 11-year-old Birmingham schoolchildren and orthodontists.
Thirty-one orthodontists practicing in Birmingham (UK) and 383 school children aged 10-11 years from a random and representative sample of seven primary schools in South Birmingham participated in the study. Participants were asked to assess five anterior photographs of the dentition representing varying degrees of aesthetic impairment of Class III and AOB malocclusions. Perceptions of dental aesthetics were determined using the aesthetic component (AC) of the Index of Orthodontic Treatment Need (IOTN).
Perceptions of dental aesthetics were similar among males and females (P > .05). Both groups allocated the highest median AC score to the photo representing severe Class III malocclusion and the lowest to the photo representing mild Class III and AOB malocclusion. Differences in perceived dental aesthetics were significant for photos representing severe Class III and moderate AOB malocclusions, with orthodontists perceiving greater aesthetic impairment for severe Class III and schoolchildren for moderate AOB, respectively (P < .05).
Schoolchildren and orthodontists perceived Class III malocclusions to have greater aesthetic impairment compared to AOB malocclusions. Surprisingly, none of the median AC scores allocated to the five photos were in the "Definite need" for treatment category. The IOTN may not be sensitive to these types of malocclusions. This finding merits further investigation.
This report presents the skeletal and dental features of “Myrtis”, an 11-year-old female resident of ancient Athens back in 430 BC. Her skeleton was unearthed in an archaeological excavation of a mass burial pit located in the outskirts of Kerameikos' ancient cemetery of Athens. “Myrtis” is believed to have been one of the numerous hapless victims of the Plague of Athens.
Her skull was found in relatively intact condition bearing her complete dentition corresponding to the mixed dentition stage. A complete dental and orthodontic diagnosis of Myrtis was conducted based on clinical examination, study of panoramic radiographs, and lateral cephalometric analysis of her skull. No significant dental pathology was reported pertaining to deciduous or permanent teeth of “Myrtis”. A Class II skeletal and dental malocclusion was observed. The ectopic labial eruption of the maxillary canines mesially to their retained deciduous predecessors, the ectopic distally directed eruption of a lower first premolar, and a unilaterally missing lower third molar were among the most interesting dental findings reported.
Eleven cases followed from enucleation of the unerupted lower second molars through third molar eruption. While results were generally good, three presented third molar malpositions requiring further treatment.
Although modern standards of ideal proportions and facial esthetics are based mostly on observations of human faces as depicted in Classical Greek masterpieces of art, the real faces of ordinary ancient Greeks have, until now, remained elusive and subject to the imagination. Objective forensic techniques of facial reconstruction have never been applied before, because human skeletal material from Classical Greece has been extremely scarce, since most decent burials of that time required cremation. Here, the authors show stage by stage the facial reconstruction of an 11-year-old girl whose skull was unearthed in excellent condition from a mass grave with victims of the Plague that struck Athens of 430 bc. The original skull was replicated via three-dimensional modeling and rapid prototyping techniques. The reconstruction followed the Manchester method, laying the facial tissues from the surface of the skull outward by using depth-marker pegs as thickness guides. The shape, size, and position of the eyes, ears, nose, and mouth were determined according to features of the underlying skeletal tissues, whereas the hairstyle followed the fashion of the time. This is the first case of facial reconstruction of a layperson residing in Athens of the Golden Age of Pericles. It is ironic, however, that this unfortunate girl who lived such a short life in ancient Athens, will now, 2500 years later, have the chance to travel and be universally recognizable in a world much bigger than anybody in ancient Athens could have ever imagined.
To assess the normative need, knowledge of, and demand for orthodontic treatment in Senegalese schoolchildren aged 12-13 years.
The sample consisted of 665 Senegalese schoolchildren randomly selected from different ethnic and socioeconomic backgrounds. The normative orthodontic treatment need was assessed using the Dental Health Component (DHC) and the Aesthetic Component (AC) of the Index of Orthodontic Treatment Need (IOTN) and the Index of Complexity, Outcome, and Need (ICON). Knowledge of and demand for orthodontic treatment were assessed with a questionnaire.
The DHC and the AC of the IOTN and the ICON classified respectively 42.6%, 8.7%, and 44.1% of the children as having a definite need for orthodontic treatment. There were no ethnic or gender differences with respect to normative orthodontic treatment need. The mean ICON score ranged from 42.31 to 44.46 according to the ethnic group. Only 10% of the children had some knowledge of orthodontics. However, between 17% and 30% of the children clearly expressed a need for orthodontic treatment, and the distribution between ethnic groups was significant. In contrast, there were no significant gender differences concerning this demand for treatment.
The present study shows that the need for orthodontic treatment far exceeds the actual available supply.
In order to define nasal breathing for diagnostic purposes, reference values of normal nasal airway size in children are needed. The purpose of this study was to examine longitudinally changes in nasal airway size that occur with age. Minimum nasal cross-sectional areas of 82 children were measured by the pressure-flow technique at 1-year intervals, from age 9 through age 13. A mixed factorial ANOVA showed that the effect of age on nasal airway size was statistically significant (p<0.001) and the effect of gender was nonsignificant. Although the mean nasal size increased from 0.4 cm2 to 0.5 cm2, it also decreased at some point between 9 and 13 years. The results suggest that the adult nasal size may be reached earlier than previously reported in cross-sectional studies.
To determine if the mandibular condylar cartilage (MCC) will grow with and without mandibular anterior repositioning appliances with the administration of insulin-like growth factor (IGF-1) and transforming growth factor-β (TGF-β).
Materials and methods:
Twenty-four growing New Zealand rabbits were divided into three groups: a group with saline injection in the temporomandibular joint, a group that received anterior positioning appliance, and a group that received injection of growth factors as well as mandibular repositioning appliance. Real-time reverse transcription polymerase chain reaction technique was used to study gene expression supported by histomorphometry.
Administration of growth factors along with mandibular repositioning appliances has induced 5.70-fold expression of matrix metalloproteinase-1 (MMP-1) (P < .0005) and 1.29-fold expression of MMP-13 (P < .0005). In contrast, administration of mandibular repositioning appliances only has induced 2.33-fold expression of MMP-1 (P < .0005) and 0.83-fold expression of MMP-13 (P < .0005). Histomorphometric analysis revealed increased proliferation of the condylar cartilage in the appliance and injection group as compared to the control group.
The administration of growth factors along with the use of mandibular advancement appliance has increased genetic expression of MMP-1 and MMP-13 supported by histomorphometric evidence indicating growth of condylar cartilage.
To create a combined male-female Chinese Bolton standard for age 13 and to compare it to the combined Bolton standard for white 13 year olds.
Materials and methods:
Thirty-two Chinese and 32 white subjects (16 adolescent boys and 16 adolescent girls aged 13 years in each ethnic group) who fulfilled the selection criteria used to create the original Bolton standards were enrolled. Their cephalograms were traced and then averaged two at a time following the Bolton method. In addition to creating the template from the 32 subjects in each group, 43 linear and angular variables were measured and compared between the two ethnic groups and between the two sexes in each ethnic group using independent t-tests. A P value of .05 was used to assign statistical significance. The male-female combined templates for 13 year olds were also compared superimposing either in the Bolton relation or by soft tissue.
No sexual dimorphism was found in the white subjects, whereas the Chinese girls had decreased upper face height (Na-ANS), more protrusive incisors (SNA-U1), and shorter cranial base (Ba-Na) and posterior cranial base (S-Ba) compared with the Chinese boys. In terms of ethnic comparison, the Chinese subjects presented shorter sagittal facial dimensions, a clockwise rotated mandible with a more acute gonial angle, and a convex facial profile with a less prominent nose and chin. However, overall vertical dimensions were similar.
A 13-year-old combined male-female Chinese Bolton standard was created that demonstrated visually and with metric comparisons that Chinese and white clinically normal subjects have different craniofacial characteristics. These differences should be taken into consideration when an individualized orthodontic treatment plan is developed.
Longitudinal growth changes in the transverse and vertical craniofacial dimensions occurring between 10 and 14 years of age were evaluated in 22 female and 23 male subjects. All subjects were healthy, had a clinically acceptable occlusion, and had not received orthodontic or orthopedic therapy before. Serial cephalometric radiographs were taken at ages 10, 11, 12, and 14 years. In studying the P-A cephalograms, seven transverse and five vertical measurements were used. The effects of age and sex on the transverse and vertical growth of the craniofacial structures were investigated by means of analysis of variance and Bonferroni multiple comparison test. The results of the study revealed that all measurements studied were affected by age, and cranial, facial, nasal, and maxillary widths were affected by sex. The most pronounced age-related increases occurred in the mandibular width for transverse measurements and in the total facial height for vertical measurements in both sexes during this study.
The purpose of this study was to evaluate the longitudinal growth changes in the incisor position, overjet, and overbite between 10 and 14 years of age. Serial cephalometric radiographs of 63 subjects (31 boys and 32 girls) were taken at the ages of 10, 11, 12, and 14. The effects of age and gender on the incisor positions, overjet, and overbite were investigated by means of variance analysis and least square difference (LSD) tests. The results show that the measurements of overbite, upper incisor-NA (mm), lower incisor-NB (mm), upper incisor-NA (angle), and the interincisal angle were affected by age. The results also show that the measurements of overbite, upper incisor-NA (mm), upper incisor-NA (angle) and upper incisor-SN (angle) were affected by gender.
Secular changes in transverse dental arch dimensions and dental arch depth were studied. Four cohorts with mixed dentitions were selected. The skull group comprised 48 skulls dating from the 14th to the 19th century and belonging to The Schreiner Collection at the Department of Anatomy, University of Oslo. The 1980s Sami group was comprised of 39 boys and 34 girls born in 1987 and living in the northern part of Norway. The 1960s Oslo group was comprised of 31 boys and 30 girls born in 1963 and living in the southern part of Norway. The 1980s Oslo group was comprised of 32 boys and 26 girls born in 1983 and living in the same area in southern Norway as the previous Oslo group. Sex was unknown in the skeletal sample, and the groups were analyzed with the sexes pooled; separate descriptive values are presented for the modern groups. The mandibular intercanine distance was smaller in the skulls compared with the modern groups. The transverse intermaxillary difference between the molars was larger in the skull group than in the 1980s Oslo group. The difference between the maxillary and mandibular intercanine distances was larger in the skulls compared with the modern groups, although the small number of measurements in the skull group impeded further analysis. The arch depth was smaller in the skull group compared with the modern groups; the 1960s Oslo group deviated because of a higher prevalence of caries in the second deciduous molars. The overjet was smaller among the skulls. The arch form measured as the angle between the left and right molar tooth rows was more acute in the skulls than in the modern groups. It was concluded that smaller arch depths are found in skeletal samples at early ages and that attrition does not explain the more upright incisors found in skeletal samples. A secular trend was found in the intermaxillary relation, which indicated that children in the 1980s Oslo group were at greater risk of developing a posterior cross-bite than children born in the 14th to 19th centuries.
To evaluate the dentoskeletal features of the "Habsburg jaw" by analyzing the skull of Joanna of Austria.
The skull, the panoramic radiograph, and the lateral cephalogram of Joanna of Austria were analyzed. The cephalometric values of Joanna were compared to cephalometric standards for adult female subjects.
The analysis of the dentition on the dry skull and on the panoramic radiograph showed a generalized horizontal alveolar bone resorption with severe bone loss that was interpreted as a sign of severe periodontal disease with respect to the young age (31 years). The cephalometric analysis revealed the presence of a skeletal Class III disharmony associated with maxillary retrusion and normal sagittal position of the mandible. The maxilla exhibited a reduction in the sagittal dimension while the mandible presented with increased dimensions both in total mandibular length (Co-Gn) and in the mandibular body (Go-Gn). The skeletal open bite contributed to the lack of mandibular protrusion though in presence of increased mandibular sagittal dimensions.
Joanna of Austria appeared to be affected by a peculiar type of "Habsburg jaw" as the Class III skeletal disharmony was due to a retrognathic maxilla rather than to a prognathic mandible.
To define a grade in the Aesthetic Component (AC) of the Index of Orthodontic Treatment Need (IOTN) that would differentiate between esthetically acceptable and unacceptable occlusions and that would also be both subjectively and objectively meaningful.
Dental appearance and self-perceived orthodontic treatment need were analyzed in a group of Finnish young adults (171 males, 263 females, age range 16-25 years). Subjective data were gathered using a questionnaire, and the respondents were requested to score their dental appearance on a visual analog type 10-grade scale. Professional assessment of dental appearance was performed by two orthodontists using the AC of the IOTN. The cutoff value between esthetically acceptable and unacceptable occlusions was defined using receiver operating characteristic curves.
Sixty-six percent of orthodontically treated and 74% of the untreated respondents were satisfied with their own dental appearance. Every third respondent reported one or more disturbing traits in their dentition. The most frequently expressed reason for dissatisfaction was crowding; girls expressed dissatisfaction more often than boys did (P = .005). A self-perceived treatment need was reported infrequently by 8% of orthodontically treated and 6% of untreated respondents. In the logistic regression analysis, self-perceived need for orthodontic treatment was the only significant factor explaining dissatisfaction with own dental esthetics. On the applied scales, grades 1 and 2 fulfilled the criteria for satisfactory dental esthetics.
The results suggest that the AC grade 3 could serve as a cutoff value between esthetically acceptable and unacceptable occlusions.
To compare the initial failure rate (≤4 months) for extra-alveolar mandibular buccal shelf (MBS) miniscrews placed in movable mucosa (MM) or attached gingiva (AG).
Materials and methods:
A total of 1680 consecutive stainless steel (SS) 2 × 12-mm MBS miniscrews were placed in 840 patients (405 males and 435 females; mean age, 16 ± 5 years). All screws were placed lateral to the alveolar process and buccal to the lower first and second molar roots. The screw heads were at least 5 mm superior to the soft tissue. Loads from 8 oz-14 oz (227 g-397 g, 231-405 cN) were used to retract the mandibular buccal segments for at least 4 months.
Overall, 121 miniscrews out of 1680 (7.2%) failed: 7.31% were in MM and 6.85% were in AG (statistically insignificant difference). Failures were unilateral in 89 patients and bilateral in 16. Left side (9.29%) failures was significantly greater (P < .001) compared with those on the right (5.12%). Average age for failure patients was 14 ± 3 years.
MBS miniscrews were highly successful (approximately 93%), but there was no significant difference between placement in MM or AG. Failures were more common on the patient's left side and in younger adolescent patients. Having 16 patients with bilateral failures suggests that a small fraction of patients (1.9%) are predisposed to failure with this method.
The purpose of this study was to evaluate the effects of 2 new acid-etching solutions, nonrinse conditioner (NRC) and 17% ethylenediaminetetraacetic acid (EDTA), on enamel surface morphology, and to compare the new solutions with traditional 37% phosphoric acid. The effect of prolonged etching time was also investigated. The buccal surfaces of 80 extracted third molars were etched with one of the 3 acids for 15, 30, or 60 seconds. The central regions of the specimens were examined with a scanning electron microscope. Shorter etching time with phosphoric acid resulted in a relatively smooth enamel surface compared with longer treatments. Irrespective of treatment time, NRC produced an aprismatic etch pattern, which suggested a potentially retentive morphological character. EDTA treatment had the least effect of all etchants tested.