CBCT Analysis of Craniofacial Transverse Dimension in Class III Malocclusions

Abstract

Objective: This study aimed to evaluate the transverse dimensions of class I and III subjects using 3D CBCT. Methods: The study included 114 subjects: 56 class III and 58 class I, aged 12-16 years old. CBCT scans for frontal and coronal images were analyzed for multiple transverse linear and angular measurements. Sex differences, ethnicity, vertical facial pattern, and other factors were assessed. All recorded data were summarized using descriptive statistics and frequency tables. Continuous variables were summarized by n, mean, standard deviation [SD], median, minimum, and maximum. Frequency count and percentage of patients within each category summarized categorical variables. To evaluate the effects of demographics and vertical facial patterns on each transverse or angular parameter, an analysis of variance (ANOVA) was used. Results: Subjects in this retrospective study were 114, with 58 (50.8%) in class I and 56 (49.1%) in class III. Half of the patients were females (50%), 35.1% were Whites, 29.8% were Hispanics or Latinos, and 35.1% were Blacks or African Americans. The age ranged between 12 and 16 years with an average (SD) of 13.8 ±1.36. There were 55 (48.2%) hypodivergent patients, 55 (48.2%) normodivergent and only 4 (3.5%) hyperdivergent. The Distributions of Demographics (age, sex, and race) and facial vertical divergence were balanced between the malocclusion classes. Transverse width analyses showed similar measurements between class I and class III. Conclusion: The results showed that patients with malocclusion class III have, on average, similar traverse measurements to those with malocclusion class I, except on the widths of the Interjugular, Mandibular intermolar width, and Maxillary Buccal width 7 mm above the alveolar crest width. Other measurements show no significant difference between classes I and III. Females had, on average, significantly smaller interjugular, antigonial, and Mandibular intermolar widths, Maxillary buccal alveolar crest width, and Maxillary Buccal widths 7 mm above the alveolar crest widths in comparison to males. All transverse dimensions’ measurements for class I and III subjects show no significant difference relative to the vertical divergence pattern (Normodivergent, Hyperdivergent, Hypodivergent). Also, it showed that African Americans have numerically more significant transverse measurements overall compared to Caucasians and Hispanics.