Designing an artificial intelligence system for dental occlusion classification using intraoral photographs: A comparative analysis between artificial intelligence-based and clinical diagnoses.

INTRODUCTION: This study aimed to design an artificial intelligence (AI) system for dental occlusion classification using intraoral photographs. Moreover, the performance of this system was compared with that of an expert clinician. METHODS: This study included 948 adult patients with permanent dentition who presented to the Department of Orthodontics, School of Dentistry, Mashhad University of Medical Sciences, during 2022-2023. The intraoral photographs taken from the patients in left, right, and frontal views (3 photographs for each patient) were collected and underwent augmentation, and about 7500 final photographs were obtained. Moreover, the patients were clinically examined by an expert orthodontist for malocclusion, overjet, and overbite and were classified into 6 groups: Class I, Class II, half-cusp Class II, Super Class I, Class III, and unclassifiable. In addition, a multistage neural network system was created and trained using the photographs of 700 patients. Then, it was used to classify the remaining 248 patients using their intraoral photographs. Finally, its performance was compared with that of the expert clinician. All statistical analyses were performed using the Stata software (version 17; Stata Corp, College Station, Tex). RESULTS: The accuracy, precision, recall, and F1 score of the AI system in the malocclusion classification of molars were calculated to be 93.1%, 88.6%, 91.2%, and 89.7%, respectively, whereas the AI system had an accuracy, precision, recall, and F1 score of 89.1%, 88.8%, 91.42%, and 89.8% for malocclusion classification of canines, respectively. Moreover, the mean absolute error of the AI system accuracy was 1.98 ± 2.11 for overjet and 1.28 ± 1.60 for overbite classifications. CONCLUSIONS: AI exhibited remarkable performance in detecting all classes of malocclusion, which was higher than that of orthodontists, especially in predicting angle classification. However, its performance was not acceptable in overjet and overbite measurement compared with expert orthodontists.

Evaluating malocclusion patterns in children with autism spectrum disorder using the index of complexity, outcome and need: a cross-sectional study.

BACKGROUND: The purpose of this study was to evaluate the complexity of malocclusion and existing patterns in children with autism spectrum disorders (ASD) using the index of complexity, outcome and need (ICON). METHODS: This cross-sectional study included children diagnosed with ASD, aged 9-15 years. A group of healthy children with the same demographic characteristics was randomly selected as the control group. Malocclusion was assessed according to ICON scoring protocol. The following parameters were recorded: dental aesthetics, upper arch crowding/spacing, presence of crossbite, anterior-vertical relationship (open and deep bite) and buccal segment anterior-posterior relationship. Finally, an overall ICON score was derived and reported for each patient. Descriptive analysis was performed for all investigated variables. Significance level was set at p < 0.05. RESULTS: A total of 324 children, divided into ASD (162) and control (162) groups, comprised the study population. Our results demonstrated that the average overall ICON score was significantly higher in the ASD group compared to the control group (38.77 vs. 27.43, p < 0.001). ASD children also obtained significantly higher scores regarding the dental aesthetics component (3.84 vs 2.78, p < 0.001). Study groups were significantly different in terms of the prevalence of incisor overbite and open bite (p = 0.002 and p < 0.001, respectively). Patients in the ASD group showed a higher prevalence of Class II and Class III malocclusions (p < 0.001). CONCLUSION: ASD children obtained significantly higher overall ICON scores, indicating more complex and severe malocclusions. These children also exhibited a greater tendency towards Class II and III malocclusions.

The association between dental and dentoalveolar arch forms of children with normal occlusion and malocclusion: a cross-sectional study.

BACKGROUND: Symmetrical and coordinated dental and alveolar arches are crucial for achieving proper occlusion. This study aimed to explore the association between dental and dentoalveolar arch forms in children with both normal occlusion and malocclusion. METHODS: 209 normal occlusion subjects (5-13 years, mean 8.48 years) and 199 malocclusion subjects (5-12 years, mean 8.19 years) were included. The dentoalveolar arch form was characterized by the smoothest projected curve representing the layered contour of the buccal alveolar bone, referred to as the LiLo curve. Subsequently, a polynomial function was utilized to assess dental and dentoalveolar arch forms. To facilitate separate analyses of shape (depth/width ratio) and size (depth and width), the widths of dental and dentoalveolar arch forms were normalized. The normalized dental and dentoalveolar arch forms (shapes) were further classified into 6 groups, termed dental/dentoalveolar arch clusters, using the k-means algorithm. RESULTS: The association between dental and dentoalveolar arch clusters was found to be one-to-many rather than one-to-one. The mismatch between dental and dentoalveolar arch forms is common in malocclusion, affecting 11.4% of the maxilla and 9.2% of the mandible, respectively. CONCLUSIONS: There are large individual variations in the association between dental and dentoalveolar arch forms. Early orthodontic treatment may play an active role in coordinating the relationship between the dental and dentoalveolar arch forms.

Characterizing infraocclusion in primary molars: prevalence, accompanying findings, and infraocclusion severity and treatment implications.

BACKGROUND: This manuscript investigates the prevalence, classification, accompanying findings, and treatment modalities associated with infraoccluded primary molars. The aim of this study categorizing primary molars based on the severity of infraocclusion and assessing their respective treatment interventions across different severity groups. METHODS: The classification, treatment types, accompanying findings, and the condition of succeeding premolars of infraoccluded molars were documented. Chi-square tests, including Fisher's Exact Chi-square test, Fisher Freeman Halton Exact Chi-square test, and One Sample Chi-square test, were conducted. The predetermined significance level was less than 0.05. RESULTS: The study population consisted of 3132 subjects aged 3 to 15 years, with a prevalence of 4.3% for infraocclusion. Infraocclusion typically manifests between 6 and 9 years of age and predominantly affects mandibular primary molars. Treatment interventions varied based on infraocclusion severity, with more invasive procedures required for severe cases. Accompanying findings associated with infraocclusion include adjacent teeth tipping, significant deviation in midline shifts towards the affected side and increased caries. Additionally, succeeding premolar agenesis was observed in 2% of infraoccluded molars, with extraction rates higher in cases where the successor tooth was mesially or distally located. CONCLUSIONS: The study offers novel insights to dental practitioners concerning the severity and distribution of treatment interventions for infraocclusion. It suggests that more severe cases may necessitate more invasive procedures, with the aim of enhancing patient outcomes through timely intervention and personalized therapeutic strategies.

Facial soft-tissue shape changes after fixed edgewise treatment with premolar extraction in individual artificial-intelligence-classified facial profile patterns.

OBJECTIVE: To examine the patterns of pretreatment facial soft tissue shape in orthodontic cases with premolar extraction using artificial intelligence (AI) and to investigate the corresponding changes. METHODS: One hundred and fifty-two patients who underwent orthodontic treatment with premolar extraction were enrolled. Lateral cephalograms were obtained before and after the treatment. For each record, the outlines of the nose-lip-chin profile and corresponding 21 cephalometric variables were extracted. The AI method classified pretreatment records into three subject groups based on the feature variables extracted from the outline. Dentoskeletal and soft tissue facial form changes observed after treatment were compared statistically (P < 0.05) between the groups using ANOVA. Multivariate regression models were used for each group. RESULTS: Group 1 (n = 59) was characterized by Class II high-angle retrognathic mandible with an incompetent lip, group 2 (n = 55) by Class I malocclusion with retruded and thin lips, and group 3 (n = 38) by Class I malocclusion with an everted superior lip before treatment. The ratios of anteroposterior soft tissue to hard tissue movements in Group 1 were 56% (r = 0.64) and 83% (r = 0.75) for the superior and inferior lips, respectively, whereas those in Group 2 were 49% (r = 0.78) and 91% (r = 0.80), and 40% (r = 0.54) and 79% (r = 0.70), respectively, in Group 3. CONCLUSIONS: The modes of facial form changes differed depending on the pre-treatment profile patterns classified by the AI. This indicates that the determination of the pre-treatment profile pattern can help in the selection of soft tissue to hard tissue movement ratios, which helps estimate the post-treatment facial profile with a moderate to high correlation.

The effect of dental and background facial attractiveness on facial attractiveness and perceived integrity and social and intellectual qualities.

INTRODUCTION: The purposes of this study were to assess the role of dental attractiveness in background facial attractiveness and to evaluate how facial and dental attractiveness influenced raters' opinions of the integrity, social attractiveness, and intellectual attractiveness of the models. METHODS: Photographs of male and female individuals rated by peers as unattractive, average, and attractive were combined with oral images of 4 different levels of dental attractiveness (Index of Orthodontic Treatment Need [IOTN] 1, 5, 7, and 10). Sixty-seven participants meeting the inclusion criteria were recruited as raters. Raters viewed closed-lip smile and open-lip, posed smile of 24 models and rated them for facial attractiveness and integrity and multiple social/intellectual attractiveness dimensions using a Visual Analog Scale. RESULTS: Intrarater reliability was fair to excellent. Analysis of variance showed significant 3-way interactions (P < 0.0001=aim 1; P < 0.005=aim 2) for model sex, facial attractiveness, and dental attractiveness. The contribution of dental attractiveness to facial attractiveness was not fixed or linear, but dependent on dental attractiveness level, background facial attractiveness, and model sex. For both sexes, dental impact on facial attractiveness was neutral or negative when teeth were less than ideal, beginning at IOTN 5 for all background facial attractiveness levels. The impact of dental attractiveness on integrity and social and intellectual attractiveness was also dependent on dental attractiveness level, background facial attractiveness, and model sex. Dental attractiveness can make dramatic differences in Average and Attractive male individuals. CONCLUSIONS: The impact of dental attractiveness on facial attractiveness and integrity and social and intellectual attractiveness was dependent on dental attractiveness level, background facial attractiveness, and model sex. The effect of dental esthetics on facial attractiveness was neutral or negative for both male and female individuals when there was a need for treatment (IOTN 5 or higher) for all levels of facial attractiveness. For both male and female models, lower dental esthetics had a greater effect on more attractive faces. Judgments about integrity and social and intellectual attractiveness were strongly affected by dental esthetics, and these effects were more dramatic and consistent for male faces.

Influence of maxillary canine impaction characteristics and factors associated with orthodontic treatment on the duration of active orthodontic traction.

INTRODUCTION: Orthodontic traction of a maxillary impacted canine (MIC) increases the orthodontic treatment time. Therefore, the objective of this study was to evaluate the influence of MIC characteristics and factors associated with orthodontic treatment on the duration of active orthodontic traction. METHODS: This follow-up and retrospective study included 45 MICs orthodontically tractioned into the occlusal plane with the use of a standardized protocol. MIC characteristics, including type, sector, side, location, height, and complexity of impaction, as well as α and ß angles and canine root length and area were measured. Likewise, factors associated with orthodontic treatment, including sex, age, malocclusion, premolar extractions, previous incisor root resorption, ANB, APDI, and SNA angles, and PNS-ANS distance were also evaluated. The statistical analysis included multiple linear regressions to estimate the influence of all variables on the duration of traction (α = 0.05). RESULTS: Sex had significant influence (P = 0.027) on the time of traction; in female patients, the time was 2.05 months more than in male patients. Bilateral impaction treatment increased the time by 2.74 months compared with unilateral cases (P = 0.001). Traction of bicortically centered impacted canines increased the duration of traction by 2.85 months (P = 0.001). Finally, the traction time increased in 2.35 months (P = 0.046) when the impaction sectors were 4 or 5 (close to the midline). CONCLUSIONS: The duration of active orthodontic traction of MIC is mainly influenced by sex, bilateral type, bicortically centered location, or when MIC is located in sector 4 or 5 close to midline, increasing the traction time by some months.

Comparing Modified Huddart-Bodenham Scoring System and GOSLON Yardstick to Assess Dental Arch Relationships in Unilateral Cleft Lip and Palate Patients.

OBJECTIVE: To test the reliability of the modified Huddart-Bodenham (MHB) numerical scoring system and its agreement with the GOSLON Yardstick categorization for assessing the dental arch relationships in unilateral cleft lip and palate (UCLP) cases. DESIGN: A retrospective study. SETTING: Faculty of Dentistry, The University of Hong Kong. PATIENTS: Forty-one nonsyndromic UCLP consecutive patients attending the Joint Cleft Lip/Palate Clinic at Faculty of Dentistry in the University of Hong Kong were selected. INTERVENTIONS: Study models at 8 to 10 years old (T1) and 10 to 12 years old (T2) were obtained from each patient. MAIN OUTCOME MEASURES: Models were rated with the MHB scoring system and GOSLON Yardstick index. The intra- and interexaminer reliabilities as well as correlation of both scoring systems were evaluated. Furthermore, to investigate the outcome measurements consistency, the MHB scoring system and GOSLON Yardstick were independently used to compare the dental arch relationships from T1 to T2, with the samples split into intervention and nonintervention groups. RESULTS: The MHB scoring system presented good intra- and interexaminer agreement, which were comparable to those of the GOSLON Yardstick. The correlation between the MHB scoring system and GOSLON Yardstick scores was good. Both scoring systems showed similar results when assessing the change in the dental arch relationships from T1 to T2. CONCLUSIONS: The MHB scoring system can be used as an alternative method to the commonly used GOSLON Yardstick for assessing dental deformities in UCLP patients. Both scoring systems showed similar results in assessing the improvement in dental arch relationships.

Treatment Outcome of Bangladeshi UCLP Patients Based on Both Phenotype and Postnatal Treatment Factors using Modified Huddart Bodenham (mHB) Index.

OBJECTIVE: To evaluate the dental arch relationship (DAR) of nonsyndromic unilateral cleft lip and palate (UCLP) and to explore the various phenotype and postnatal treatment factors that are responsible for poor DAR. DESIGN: Retrospective study. SETTING: School of Dental Science, Universiti Sains Malaysia. SUBJECTS: Eighty-four Bangladeshi children with nonsyndromic UCLP who received cheiloplasty and palatoplasty. MAIN OUTCOME MEASURES: Dental models were taken at 5 to 12 years of age (man: 7.69), and dental arch relationships were assessed using modified Huddart/Bodenham index (mHB) by two raters. Kappa statistics was used to evaluate the intra- and interexaminer agreements, chi-square was used to assess the associations, and logistic regression analysis was used to explore the responsible factors that affect DAR. RESULTS: The total mHB score (mean [SD]) was -8.261 (7.115). Intra- and interagreement was very good. Using crude and stepwise backward regression analysis, significant association was found between positive history of class III (P = .025, P = .030, respectively) and unfavorable DAR. Complete UCLP (P = .003) was also significantly correlated with unfavorable DAR. CONCLUSION: This multivariate study suggested complete type of UCLP and positive history of class III had a significantly unfavorable effect on the DAR.

Effects of supplemental vibrational force on space closure, treatment duration, and occlusal outcome: A multicenter randomized clinical trial.

INTRODUCTION: A multicenter parallel 3-arm randomized clinical trial was carried out in 3 university hospitals in the United Kingdom to investigate the effect of supplemental vibratory force on space closure and treatment outcome with fixed appliances. METHODS: Eighty-one subjects less than 20 years of age with mandibular incisor irregularity undergoing extraction-based fixed appliance treatment were randomly allocated to supplementary (20 minutes/day) use of an intraoral vibrational device (AcceleDent; OrthoAccel Technologies, Houston, Tex) (n = 29), an identical nonfunctional (sham) device (n = 25), or fixed-appliance only (n = 27). Space closure in the mandibular arch was measured from dental study casts taken at the start of space closure, at the next appointment, and at completion of space closure. Final records were taken at completion of treatment. Data were analyzed blindly on a per-protocol basis with descriptive statistics, 1-way analysis of variance, and linear regression modeling with 95% confidence intervals. RESULTS: Sixty-one subjects remained in the trial at start of space closure, with all 3 groups comparable for baseline characteristics. The overall median rate of initial mandibular arch space closure (primary outcome) was 0.89 mm per month with no difference for either the AcceleDent group (difference, -0.09 mm/month; 95% CI, -0.39 to 0.22 mm/month; P = 0.57) or the sham group (difference, -0.02 mm/month; 95% CI, -0.32 to 0.29 mm/month; P = 0.91) compared with the fixed only group. Similarly, no significant differences were identified between groups for secondary outcomes, including overall treatment duration (median, 18.6 months; P >0.05), number of visits (median, 12; P >0.05), and percentage of improvement in the Peer Assessment Rating (median, 90.0%; P >0.05). CONCLUSIONS: Supplemental vibratory force during orthodontic treatment with fixed appliances does not affect space closure, treatment duration, total number of visits, or final occlusal outcome. REGISTRATION: NCT02314975. PROTOCOL: The protocol was not published before trial commencement. FUNDING: AcceleDent units were donated by OrthoAccel Technologies; no contribution to the conduct or the writing of this study was made by the manufacturer.

Objective assessment of the contribution of dental esthetics and facial attractiveness in men via eye tracking.

INTRODUCTION: Recently, greater emphasis has been placed on smile esthetics in dentistry. Eye tracking has been used to objectively evaluate attention to the dentition (mouth) in female models with different levels of dental esthetics quantified by the aesthetic component of the Index of Orthodontic Treatment Need (IOTN). This has not been accomplished in men. Our objective was to determine the visual attention to the mouth in men with different levels of dental esthetics (IOTN levels) and background facial attractiveness, for both male and female raters, using eye tracking. METHODS: Facial images of men rated as unattractive, average, and attractive were digitally manipulated and paired with validated oral images, IOTN levels 1 (no treatment need), 7 (borderline treatment need), and 10 (definite treatment need). Sixty-four raters meeting the inclusion criteria were included in the data analysis. Each rater was calibrated in the eye tracker and randomly viewed the composite images for 3 seconds, twice for reliability. RESULTS: Reliability was good or excellent (intraclass correlation coefficients, 0.6-0.9). Significant interactions were observed with factorial repeated-measures analysis of variance and the Tukey-Kramer method for density and duration of fixations in the interactions of model facial attractiveness by area of the face (P <0.0001, P <0.0001, respectively), dental esthetics (IOTN) by area of the face (P <0.0001, P <0.0001, respectively), and rater sex by area of the face (P = 0.0166, P = 0.0290, respectively). For area by facial attractiveness, the hierarchy of visual attention in unattractive and attractive models was eye, mouth, and nose, but for men of average attractiveness, it was mouth, eye, and nose. For dental esthetics by area, at IOTN 7, the mouth had significantly more visual attention than it did at IOTN 1 and significantly more than the nose. At IOTN 10, the mouth received significantly more attention than at IOTN 7 and surpassed the nose and eye. These findings were irrespective of facial attractiveness levels. For rater sex by area in visual density, women showed significantly more attention to the eyes than did men, and only men showed significantly more attention to the mouth over the nose. CONCLUSIONS: Visual attention to the mouth was the greatest in men of average facial attractiveness, irrespective of dental esthetics. In borderline dental esthetics (IOTN 7), the eye and mouth were statistically indistinguishable, but in the most unesthetic dental attractiveness level (IOTN 10), the mouth exceeded the eye. The most unesthetic malocclusion significantly attracted visual attention in men. Male and female raters showed differences in their visual attention to male faces. Laypersons gave significant visual attention to poor dental esthetics in men, irrespective of background attractiveness; this was counter to what was seen in women.

Incisor malalignment and the risk of periodontal disease progression.

INTRODUCTION: The objective of this study was to investigate the association between incisor crowding, irregularity, and periodontal disease progression in the anterior teeth. METHODS: Data collected over 35 years from men enrolled in the Veterans Affairs Dental Longitudinal Study included information concerning pocket depth and alveolar bone loss. Plaster casts of the maxillary (n = 400) and mandibular (n = 408) arches were available for baseline measurements. Periodontal disease in the anterior teeth was defined as per arch sum of pathologic pocket depth and sum of teeth with any alveolar bone loss in the anterior sextants. Incisor malalignment status was defined by the anterior tooth size-arch length discrepancy index and Little's Irregularity Index. Adjusted mixed effects linear models computed the beta (ß) estimates and 95% confidence intervals (95% CI) of the amounts of change in periodontal disease outcomes by the level of malalignment. RESULTS: In the anterior maxillary arch, crowding and spacing were significantly associated with an increased per-arch sum of pathologic pocket depth (ß, 0.70 mm; 95% CI, 0.20-1.21, and ß, 0.49 mm; 95% CI, 0.06-0.91, respectively). In the anterior mandibular arch, incisor crowding and irregularity were significantly associated with an increased per-arch sum of pathologic pocket depth (mild crowding: ß, 0.47 mm; 95% CI, 0.01-0.93; severe irregularity: ß, 0.94 mm; 95% CI, 0.50-1.38), and the sum number of teeth with alveolar bone loss (mild and moderate-to-severe crowding: ß, 0.45 teeth; 95% CI, 0.08-0.82; and ß, 0.45 teeth; 95% CI, 0.13-0.83, respectively; moderate irregularity: ß, 0.34 teeth; 95% CI, 0.06-0.62). CONCLUSIONS: Certain incisor malalignment traits (ie, maxillary incisor crowding, maxillary incisor spacing, mandibular incisor mild crowding, mandibular incisor moderate-to-severe crowding, mandibular incisor moderate irregularity, and mandibular incisor severe irregularity) are associated with significant periodontal disease progression.

Effectiveness of the American Board of Orthodontics Discrepancy Index in predicting Treatment Time.

AIM: This study was aimed to explore the effect of pretreatment severity of malocclusion on the duration of the treatment using The American Board of Orthodontics discrepancy index (ABO-DI). MATERIALS AND METHODS: This clinical retrospective study consisted of orthodontics records of 37 patients who were treated with comprehensive fixed orthodontic appliance from 2011 to 2013. The sample of the study was collected so as to exclude, to the maximum possible, the patient cooperation variability by reviewing all patient chart entries. The DI measurements were used to gather the information of the pretreatment and relate it to the time duration of the treatment. Statistical analyses were performed using the chi-square test and Pearson correlation coefficient. RESULTS: The average treatment time was 24.5 months. The DI scores mean for class I and II was 14.30 and 20.15 respectively. Age and sex did not significantly influence the treatment duration (p > 0.05). CONCLUSION: The results of this study showed that the ABO-DI could be a useful tool to predict orthodontic treatment time. CLINICAL SIGNIFICANCE: The ABO-DI can significantly aid in orthodontic treatment time planning.

Validity of the American Board of Orthodontics Discrepancy Index and the Peer Assessment Rating Index for comprehensive evaluation of malocclusion severity.

OBJECTIVES: To assess the validity of the American Board of Orthodontics Discrepancy Index (ABO-DI) and Peer Assessment Rating (PAR) Index in evaluating malocclusion severity in Chinese orthodontic patients. SETTING AND SAMPLE POPULATION: A stratified random sample of 120 orthodontic patients based on Angle classification was collected from six university orthodontic centres. MATERIAL AND METHODS: Sixty-nine orthodontists rated malocclusion severity on a five-point scale by assessing a full set of pre-treatment records for each case and listed reasons for their decision. Their judgement was then compared with ABO-DI and PAR scores determined by three calibrated examiners. RESULTS: Excellent interexaminer reliability of clinician judgement, ABO-DI and PAR index was demonstrated by the Intraclass Correlation Coefficient (rho= 0.995, 0.990 and 0.964, respectively). Both the ABO-DI and US-PAR index showed good correlation with clinician judgement (r=.700 and r=.707, respectively). There was variability among the different Angle classifications: the ABO-DI showed the highest correlation with clinician judgement in Class II patients (r=.780), whereas the US-PAR index showed the highest correlation with clinician judgement in Class III patients (r=.710). Both indices demonstrated the lowest correlations with clinician judgement in Class I patients. CONCLUSION: With strong interexaminer agreement, the panel consensus was used for validating the ABO-DI and US-PAR index for malocclusion severity. Overall, the ABO-DI and US-PAR index were reliable for measuring malocclusion severity with significantly variable weightings for different Angle classifications. Further modification of the indices for different Angle classification may be indicated.

A Morphological Classification Scheme for the Mandibular Hypoplasia in Treacher Collins Syndrome.

BACKGROUND: Mandibular hypoplasia is a hallmark of Treacher Collins syndrome (TCS), and its severity accounts for significant functional morbidity. The purpose of this study is to develop a mandibular classification scheme. METHODS: A classification scheme was designed based on three-dimensional computed tomography (3D-CT) scans to assess 3 characteristic features: degree of condylar hypoplasia, mandibular plane angle (condylion-gonion-menton), and degree of retrognathia (sella-nasion-B point angle). Each category was graded from I to IV and a composite mandible classification was determined by the median value among the 3 component grades. RESULTS: Twenty patients with TCS, aged 1 month to 20 years, with at least one 3D-CT prior to mandibular surgery were studied. Overall, 33 3D-CTs were evaluated and ordered from least to most severe phenotype with 10 (30%) Grade 1 (least severe), 14 (42%) Grade 2, 7 (21%) Grade 3, and 2 (7%) Grade 4 (most severe). Seven patients had at least 2 longitudinal scans encompassing an average 5.7 (range 5-11) years of growth. Despite increasing age, mandibular classification (both components and composite) remained stable in those patients over time (P = 0.2182). CONCLUSION: The authors present a classification scheme for the TCS mandible based on degree of condylar hypoplasia, mandibular plane angle (Co-Go-Me angle), and retrognathia (SNB angle). While there is a natural progression of the mandibular morphology with age, patients followed longitudinally demonstrate consistency in their classification. Further work is needed to determine the classification scheme's validity, generalizability, and overall utility.

Changes in posterior airway space and hyoid bone position after surgical mandibular advancement.

OBJECTIVE: To evaluate cephalometric changes in posterior airway space (PAS) and in hyoid bone distance to mandibular plane (MP) 1-3 years after bilateral sagittal split osteotomy (BSSO). MATERIAL AND METHODS: The sample consisted of 36 females and 16 males who underwent mandibular advancement by BSSO. To observe sagittal changes in PAS and in hyoid bone distance to MP both pre- and postoperative cephalograms were analyzed using WinCeph® 8.0 software. For the statistical analyses paired T-test and multivariate logistic regression models were used. RESULTS: By the surgical-orthognathic treatment the sagittal dimension of PAS showed variable changes but it mainly diminished when the mandibular advancement exceeded 6 mm. In most cases the hyoid bone moved superiorly by BSSO. Logistic regression models showed that males, patients with narrow PAS at the baseline, and those with counterclockwise rotation of the mandible by the treatment gained more increase in PAS. However, an increase in sagittal PAS dimension tended to relapse over time. Concerning the movement of the hyoid it was found that the more PAS increased the less hyoid moved superiorly. In males the change in hyoid position was more obvious than in females. CONCLUSION: Males, patients with narrow PAS at the baseline, and those whose mandible moved in the counterclockwise direction with moderate advancement gained more retrolingual airway patency by BSSO.

The Prevalence of Major Types of Occlusal Anomalies among Saudi Middle School Students.

INTRODUCTION: Malocclusion is the most common dental anomaly among children and adolescents. Accordingly, this study was conducted to investigate the prevalence of major types of occlusal anomalies in permanent dentition among Saudi Arabian middle school adolescent students seeking orthodontic treatment in Jeddah. MATERIALS AND METHODS: The sample comprised 150 males and 150 females with mean age of 14.25 (±1.09) for both males and females. Data were registered using the Bjork method. RESULTS: The results of the study showed that postnormal occlusion, prenormal occlusion, and bimaxillary protrusion represented 22, 14.7, and 8.3% of the studied sample respectively. Moderate and severe overjet accounted for 24.7 and 5.7% and for overbite 28 and 13% respectively. Midline deviation was detected in 25.3% of the sample. Mild, moderate, and severe maxillary and mandibular crowding represented 10, 27.3, and 10% and 13, 40, and 9.7% respectively. CONCLUSION: The prevalence of occlusal anomalies was 90% and some occlusal anomalies were higher in females. CLINICAL SIGNIFICANCE: The prevalence of occlusal anomalies in Saudi Arabian middle school students necessitates the demand for obtaining baseline data for planning orthodontic services.

Efficiency of Class II subdivision malocclusion treatment with 3 and 4 premolar extractions.

INTRODUCTION: In this study, we compared the efficiency of Class II subdivision malocclusion treatment with symmetric and asymmetric extractions. METHODS: A sample of 71 patients with complete Class II subdivision malocclusion was selected: group 1 consisted of 40 patients treated with 4 premolar extractions with an initial mean age of 13.37 years, and group 2 had 31 patients treated with 3 premolar extractions (2 maxillary premolars and 1 mandibular premolar on the Class I side) with an initial mean age of 14.44 years. To compare the efficiency of each treatment protocol, the initial and final occlusal results were evaluated on dental casts with the Peer Assessment Rating occlusal index, and time spent in treatment was calculated from the clinical charts. The amounts of initial and final midline deviation and improvement of midline deviation correction were also evaluated. Efficiency was calculated as the rate between occlusal improvement by the treatment time. The groups were compared with t and Mann-Whitney tests. RESULTS: The results showed that group 2 had a significantly smaller final amount of midline deviation and a greater correction of midline deviation. CONCLUSIONS: Treatment efficiency of type 1 Class II subdivision malocclusions with 3 or 4 premolar extractions is similar. However, treatment with 3 premolar extractions provides a better occlusal success rate.

Impact of orthosurgical treatment phases on oral health-related quality of life.

INTRODUCTION: In this cross-sectional study, we investigated the impact of the orthosurgical treatment phases on the oral health-related and condition-specific quality of life (QoL) of patients with dentofacial deformities. METHODS: Two hundred fifty-four orthognathic patients were allocated into 4 groups according to treatment phase: initial (not yet treated), presurgical orthodontics, postsurgical orthodontics, and retention. Data were collected using the Oral Health Impact Profile to evaluate the oral health-related QoL, the Orthognathic QoL Questionnaire to analyze the condition-specific QoL, and the Index of Orthodontic Treatment Need to assess malocclusion severity and esthetic impairment. Specific malocclusion characteristics were also documented. RESULTS: A negative binomial regression analysis showed that the initial group had a more negative oral health-related QoL than did the postsurgical, presurgical, and retention groups (relative risks, 1, 0.79, 0.74 and 0.25, respectively). The initial group had a more negative condition-specific QoL than did the presurgical, postsurgical, and retention groups (relative risks, 1, 0.77, 0.38 and 0.15, respectively) regardless of age, income, or education; women reported greater negative impacts than men. Certain occlusal traits were related to higher Orthognathic QoL Questionnaire scores (P <0.01). CONCLUSIONS: Patients who completed their orthosurgical treatment had a significantly better oral health-related QoL and a more positive esthetic self-perception than did those undergoing treatment and those who were untreated. Crowding, crossbite, open bite, concave profile, edge-to-edge overjet, or Class III malocclusion negatively affected oral health-related QoL.

Effect of different incisor movements on the soft tissue profile measured in reference to a rough-surfaced palatal implant.

INTRODUCTION: The aim of this study was to evaluate soft tissue profile changes after a wide range of incisor movements in the anterior and posterior directions in nongrowing patients. Identifying baseline values more prone to substantial soft tissue profile changes was of high interest. METHODS: For this retrospective study, 47 pairs of lateral cephalograms of nongrowing white patients were superimposed. The cephalograms were taken with the same palatal implant in situ before and after treatment. To increase the accuracy of the measurements, the palatal implants were used as stable reference structures in close relation to the incisors. RESULTS: Horizontal changes of the most anterior point of the maxillary incisor showed a significant correlation to horizontal changes of the upper and lower lips (P <0.001). For every millimeter of horizontal change of the most anterior point of the maxillary central incisor, a change of 0.59 mm at labrale superior can be expected. Also, the angulations of the upper and lower lips were significantly correlated to the most anterior point of the maxillary incisor. Lip retraction was less pronounced in patients with initially thicker lips than in those with thinner lips. CONCLUSIONS: The major contributing factors for predicting the soft tissue profile change during orthodontic treatment are the amount of horizontal movement of the most anterior point of the maxillary incisor, the amount of bite opening, and the initial lip thickness. Although there are significant correlations between dental movements and soft tissue changes in larger samples, predictions for individuals may be inconsistent.