Dentoskeletal effects and "effective" temporomandibular joint, maxilla and chin changes in good and bad responders to van Beek activator treatment

Objective: To assess possible differences in dentoskeletal effects and "effective" temporomandibular joint, maxilla, and chin changes between good and bad responders to van Beek activator treatment. Materials and Methods: The subject material consisted of 20 consecutive normodivergent male Class II division 1 patients treated with a van Beek activator. Because of insufficient cooperation, four patients were excluded. Lateral head films were taken 6 months before treatment, at start of treatment, and after 12 months of treatment. The patients were placed into a good responder group (successful, n = 8) and a bad responder group (unsuccessful, n = 8). An overjet reduction ≥4 mm was considered successful. Results: During the van Beek treatment period, the good responders showed a significantly larger improvement in overjet and molar relationship than did the bad responders. The good responders exhibited a significant posterior development of condylion, less anterior mandibular autorotation, retrusion of upper incisors, protrusion of lower incisors, distalization of maxillary molars, and a mesial movement of mandibular molars. No significant dental movements were seen in the bad responders. Conclusions: Although van Beek activator treatment affected the direction of condylar growth, as well as the direction of maxilla and chin changes, it can be concluded that skeletal changes did not contribute to the Class II correction. Instead, overjet reduction during van Beek activator treatment was found to be due to a favorable dental reaction. © 2006 by The EH Angle Education and Research Foundation, Inc.link_to_subscribed_fulltex

Overjet correction and space closure mechanisms for Class II treatment by extracting the maxillary first molars

Item does not contain fulltextOBJECTIVE: To analyze the mechanism of overjet correction and space closure when treating Class II Division 1 patients by extracting the maxillary first molars. PATIENTS AND METHODS: A total of 100 prospective, consecutively treated Class II Division 1 patients (45 female, 55 male; 10.5-17.2 years old). Standardized lateral cephalograms prior to and after treatment were evaluated via a modified sagittal occlusion analysis (SO analysis). RESULTS: The mean degree of overjet correction was 5.2 mm (95% CI = 4.8-5.6 mm) and was on average achieved by means of 1.7 mm skeletal and 3.5 mm dental changes. The relationship between the premolars improved by 4.8 mm toward a Class I relationship, facilitated by 1.7 mm skeletal and 3.1 mm dental changes. The 11.3 mm space closure in the maxillary first-molar extraction area resulted from distalization of the second premolars (1.4 mm) and a mesialization of the second molars (9.9 mm). CONCLUSIONS: Overjet correction was essentially achieved by a retrusion of the upper incisors, as well as by ventral growth of the lower jaw and protrusion of the lower incisors. Space closure was only partly achieved by distalization of the premolars