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.

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Objectives:The aim of this prospective study was to assess the amount of interlabial gap (ILG) and freeway space (FWS) at rest position (RP) according to gender, age, and skeletal pattern, and to evaluate the cephalometric measurements at maximum intercuspal position (MIP) and at RP to define the cephalometric changes from MIP to RP related to the amount of ILG and FWS. Methods: Lateral cephalograms and photographs of selected subjects (47 females, 57 males) were obtained at MIP and RP. Cephalometric measurements at MIP and RP and their differences were measured and compared. Results: ILG (P > 0.05) and FWS (P < 0.01) were greater in males than in females. ILG (P < 0.05) and FWS (P > 0.05) were greater in adolescents than in adults. ILG and FWS were not significantly related with the vertical skeletal pattern (FHR, facial height ratio). ILG was the greatest in Class II cases but without significance. FWS was significantly greater in Class III than in Class I and Class II cases (P < 0.05). At MIP, the ILG at RP increased as overjet (P < 0.05) and upper lip to the aesthetic line (P < 0.01) increased. At RP, the ILG increased as upper incisor exposure and the lips to the aesthetic line increased (P < 0.001), and FWS decreased as overbite decreased (P < 0.001). From MIP to RP, lip length showed the greatest decrease (P < 0.001) in the large ILG group. Additionally, Bjork sum (the sum of the saddle, articular, and gonial angles), mandibular plane angle, anterior facial height, and ANB (P < 0.001) showed the greatest increase, while OB (P < 0.001) showed the greatest decrease in the large FWS group. The lip competent group showed the largest frequency distribution in the small ILG and FWS groups, while smile line frequency distribution showed no relationship with the level of ILG and FWS. Conclusions: Taking cephalometric measurements at RP would be helpful to evaluate the ILG and FWS more accurately, and to provide a more accurate diagnosis and treatment plan.

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Objective: To investigate the cephalometric changes following anterior repositioning of the mandible for predicting the treatment effects in Class II adolescent patients. Study Design: Lateral cephalograms of 28 patients (ANB &gt; 4°) were taken in centric occlusion (CO) and edge-to-edge bite (EtoE) before orthodontic treatment. The patients were classified into two groups according to their mandibular plane angle [MPA; low MPA (LMPA) ≤ 28° and high MPA (HMPA) &gt; 28°]. Cephalometric changes of hard and soft tissues were measured and analyzed with an x-y cranial base coordinate system. Results: For CO to EtoE, there were no significant cephalometric changes between HMPA and LMPA, but the horizontal ratio of soft to hard tissue pogonion (H-Pog′/H-Pog) change was significantly greater with LMPA than with HMPA while the vertical ratio (V-Pog′/V-Pog) showed vice versa. For CO to EtoE, MPA showed significant correlations with H-Pog′/H-Pog and V-Pog′/V-Pog. Y-axis angle, V-Pog′/V-Pog and H-Pog′/H-Pog can be used as good tools to discriminate between HMPA and LMPA. Conclusion: Cephalometric findings for CO to EtoE may be useful in predicting the vertical and horizontal changes of hard and soft tissues with the treatment of growing adolescents having various vertical skeletal patterns of Class II malocclusion.