Relationship between mandibular symphysis dimensions and skeletal pattern in adults.

BACKGROUND: The knowledge of dimensions of the symphysis is important for morphological and orthodontic studies. This research evaluates the association between mandibular symphysis dimensions and anteroposterior and vertical skeletal patterns in adults. MATERIALS AND METHODS: This cross-sectional cephalometric study included 90 lateral cephalograms of untreated subjects presenting for orthodontic treatment. The inclusion criteria were adults with lateral cephalograms showing the symphyseal region and anterior cranial base. One investigator traced and analysed all cephalograms. Symphyseal height, thickness, and ratio between height and thickness were measured in relation to seven anteroposterior and vertical skeletal measurements in females and males. RESULTS: Symphyseal measurements were associated with SNAo (anteroposterior) in females and Gonial angle (vertical) in males. When analysed by anteroposterior skeletal classification (ANBo), no significant differences in symphyseal dimensions were found. Multiple linear regression analyses showed that Gonion-Nerve (mm) and Gonial angle were significantly associated with symphyseal height. Gonion-Nerve (mm), basal bone width (mm), and alveolar bone height (mm) were associated with symphyseal thickness. Basal bone width (mm) and alveolar bone height (mm) were associated with symphyseal ratio. CONCLUSIONS: Symphyseal dimensions were significantly associated with vertical but not anteroposterior skeletal patterns. Future studies are warranted to evaluate the Gonion-Nerve measurements concerning the symphysis in relation to vertical and anteroposterior skeletal patterns.

Dental and soft tissue changes following extraction of second premolars in females with bimaxillary protrusion: A retrospective study.

BACKGROUND: Bimaxillary protrusion is a condition wherein esthetic concerns are the main reason behind seeking orthodontic treatment. AIM: The aim of this retrospective cephalometric study was to evaluate the soft tissue profile and dental changes among female Saudi bimaxillary protrusion patients treated with extraction of all second premolars followed by retraction of the anterior teeth. Subjects and Methods: Pre and posttreatment cephalometric radiographs of adult female patients (ages 18-30 years) who underwent orthodontic therapy for Class I bimaxillary protrusion were obtained. Data were analyzed with SPSS® software. A paired t-test and Pearson's correlation coefficients were conducted with the statistical significance set at 95% (P value < 0.05). RESULTS: At posttreatment, there was an overall decrease in the mean values among the majority of the soft tissue and dental cephalometric angles and linear measurements. Among soft tissue variables, there was a marginal increase in the upper lip length by 1.49 mm (P < 0.001), and the nasolabial angle increased markedly by 7.64° (P < 0.001). Similarly, a marked increase in retroclination by 5.95° (P < 0.001) was observed among the dental variables. Conversely, no significant changes were noted in the lower incisors. Pearson's correlation analysis revealed a significant correlation between all the different dental variables. Within the soft tissue variables, there was a significant positive correlation between changes in the upper lip protrusion, lower lip protrusion, upper lip thickness, and the distance from the upper and lower lips to the S-line.

Orthodontic Treatment Characteristics and Outcomes in an Educational Setting.

BACKGROUND: To assess and correlate orthodontic treatment characteristics and outcomes in an educational setting. METHODS: A total of 287 patients were included. Independent chart reviews were conducted to gather demographic and pretreatment diagnostic information. Posttreatment digital records were graded with the ABO C-R Eval and the CCA methods. Pearson correlation coefficients were calculated to determine associations between variables. RESULTS: Of the 287 patients, 122 (42.5%) were male and 165 (57.5%) were female. The total average treatment time was 33.87 ± 10.28 months, with a range from 11 to 75 months. The mean ABO C-R Eval score was 29.10 ± 8.59 points. The parameters with the highest scores were buccolingual inclination and occlusal contacts. The mean CCA score was 3.36 ± 2.05 points. The highest scores were recorded for dental esthetics and management of the periodontium. Higher ABO DI scores were weakly correlated with longer treatment times (r = 0.258; p < 0.001). ABO C-R Eval scores showed a weakly significant association with treatment duration (r = 0.162; p=0.006), while CCA scores were moderately associated with treatment duration (r = 0.451; p < 0.001). CONCLUSIONS: As treatment duration increased, the total ABO C-R Eval and CCA scores tended to increase; thus, quality of treatment outcomes decreased. A significant positive correlation was also found with the ABO DI score and treatment duration.