Class II Division 1 Adolescent Treatment with Twin Block and Fixed Orthodontic Appliances: 3-Dimensional Changes of the Temporomandibular Joint.

INTRODUCTION: Skeletal Class II division 1 malocclusions with a retrognathic mandible can be treated with Twin Block and fixed orthodontic appliances in growing adolescent patients. OBJECTIVE: The aim of this case report was to show successful treatment results following step-by-step procedures determined by visualizing the changes of the temporomandibular joint (TMJ) area using cone-beam computed tomography (CBCT) images. CASE REPORT: A 10-year, 8-month-old female adolescent with skeletal Class II division 1 (ANB, 6.2°), severe overjet (8.4 mm), and overbite (7.8 mm) was treated with Twin Block and fixed orthodontic appliances. After wearing an active plate for 4 months, a Twin Block appliance for 9 months, a retainer with an inclined plane for 13 months, and fixed orthodontic treatment for 17 months, her skeletal Class II was corrected. After 39 months of posttreatment retention, good treatment results were maintained with favorable occlusion and facial balance. Acceptable 3-dimensional changes of the TMJ area were identified using cone-beam computed tomography images. CONCLUSION: A female adolescent patient with skeletal Class II division 1 malocclusion, severe overjet and overbite, and mandibular retrusion was treated using Twin Block and fixed orthodontic appliances. Acceptable 3-dimensional changes in the TMJ area and 2-dimensional growth of the mandible were identified using CBCT and cephalometric images.

Evaluation of condyle-fossa relationships in adolescents with various skeletal patterns using cone-beam computed tomography.

OBJECTIVES: To evaluate the condyle-fossa relationship in adolescents with various skeletal patterns using cone-beam computed tomography (CBCT). MATERIALS AND METHODS: CBCT images obtained in 120 adolescent patients were used for this study. The patients were divided into 3 groups according to 3 criteria: (1) age (early, middle, and late adolescence); (2) facial height ratio or Jarabak quotient (hyperdivergent, normodivergent, and hypodivergent); and (3) ANB classification (Class I, Class II, and Class III). Temporomandibular joint space (TMJS: AS, anterior space; SS, superior space; PS, posterior space; MS, medial space; LS, lateral space), width and depth of the condyle (MLT, mediolateral thickness; APT, anteroposterior thickness), articular slope (ArS) and vertical height of the fossa (VHF) were measured and compared using CBCT. RESULTS: Differences in condyle-fossa relationships were not significantly different between male and female adolescents, but were significantly different (P < .05) between left and right sides. The mean values showed no statistical differences according to age and skeletal pattern. Most measurements in the sagittal view showed that SS was the greatest, and the mean ratio of AS to SS to PS was 1.00 to 1.27 to 1.19, respectively. The mean values of coronal MS and LS were not significantly different. CONCLUSIONS: There were almost no statistical differences in the TMJS in adolescents across various factors except between left and right sides.