[Mode of new bone formation following distraction osteogenesis in mandibular lengthening].
ABSTRACT To investigate the mode and influential factor of new bone formation following distraction osteogenesis in mandibular lengthening.
Corticotomy was performed on bilateral mandibles in twelve adult male goats. A custom-made distractor was used to lengthen the mandible at a rate of 1 mm/day for 10 days (total 10 mm elongation). Four goats were sampled respectively at 2, 4 and 8 weeks after completion of distraction. The lengthening mandibles were examined by roentgenography and histology.
Newly formed callus was observed in the distraction gap after mandibular lengthening. The new bone exhibited intramembranous ossification generally, but cartilage islands could be found in the specimen that distractor loosed.
The above findings indicate that the mode of new bone formation in mandibular lengthening following distraction osteogenesis appears to be intramembranous ossification and that endochondral ossification takes place in case distractor has loosened.
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ABSTRACT: 425 patients with mandibular angle fractures were treated at the Hospital of Kaunas University of Medicine (HKUM) Clinic of Maxillo-Facial Surgery. Treatment included the application of closed fracture fragments fixation methods (wire splint fixation, and Kirschner wire osteosynthesis), and methods of open fixation--osteosynthesis using the supra-periosteal miniplate, and osteosynthesis using supra-osseous Zes Pol plate (the latter method was modified by the authors). Relative computerized densitometry showed that closed fixation methods result in a faster healing of fractures. The findings of the pain threshold testing showed that open fixation methods more severely damage the function of the lower alveolar nerve. Using closed fixation methods, osteomyelitis occurred in 5.3% of cases, while using open fixation methods--in 15.3% of cases. Thus, the authors of the article maintain that when mandibular angle fractures, in the presence of suitable conditions, closed fracture fragments fixation methods should be given a priority.Stomatologija / issued by public institution "Odontologijos studija" ... [et al.] 02/2005; 7(2):35-9.