Outcomes of early versus late treatment of severe Class II high-angle patients.

INTRODUCTION: The aim of this work was to compare the skeletal and dental outcomes of 1- versus 2-phase treatment in Class II subjects with difficult-to-treat high-angle severe Class II malocclusions. METHODS: The sample of 120 cases was collected from the private offices of 3 experienced clinicians. The following selection criteria were used: (1) ANB ≥6°, (2) SN-GoGn ≥37° or mandibular plane to Frankfort horizontal plane ≥30°; and (3) overjet ≥6 mm. Patients were classified into either the early or the late treatment group according to dental age (early Tx: ≥5 primary teeth; late Tx: otherwise). Thirty-four angular, linear, and proportional measurements were determined for each patient. Statistical significance was assessed with the use of a 2-tailed t test, analysis of covariance test, and chi-square test. RESULTS: The results showed that early 2-phase treatment for severe Class II high-angle patients offered no skeletal anteroposterior advantages over late 1-phase treatment. Severe high-angle Class II patients also showed similar dental anteroposterior outcomes with the use of both approaches. Vertically there was a higher frequency of increased mandibular plane angles and extrusion of upper incisors and lower molars in the late treatment group. CONCLUSIONS: Early 2-phase treatment for severe Class II high-angle patients offered no skeletal or dental advantage over late 1-phase treatment.

Accelerated Bone Formation in Distracted Alveolar Bone After Injection of Recombinant Human Bone Morphogenetic Protein-2.

BACKGROUND: This study evaluates the effect of recombinant human bone morphogenetic protein-2 (rhBMP-2) on the quality and quantity of regenerated bone when injected into distracted alveolar bone. METHODS: Sixteen adult beagle dogs were assigned to either the control or rhBMP-2 group. After distraction was completed, an rhBMP-2 dose of 330 µg in 0.33 mL was injected slowly into the distracted alveolar crest of the mesial, middle, and distal parts of the alveolar bone in the experimental group. Histologic and microcomputed tomography analyses of regenerated bone were done after 2 and 6 weeks of consolidation. RESULTS: After 6 weeks of consolidation, the vertical defect height in the middle of the regenerated bone was significantly lower in the rhBMP-2 group (2.2 mm) than in the control group (3.4 mm) (P <0.05). Additionally, the width of the regenerated bone was significantly greater in the rhBMP-2 group (4.3 mm) than in the control group (2.8 mm) (P <0.05). The bone density and volume of regenerated bone in the rhBMP-2 group were greater than in the control group after 6 weeks of consolidation (P <0.001). CONCLUSION: Injection of rhBMP-2 into regenerated bone after a distraction osteogenesis procedure significantly increased bone volume in the dentoalveolar distraction site and improved both the width and height of the alveolar ridge and increased the bone density.