Abstract
Purpose: Evaluation of the effect of unilateral mandibular lengthening by distraction osteogenesis at a rapid, hyperphysiologic, rate of 2 mm per day on the temporomandibular joint. Materials and Methods: Eighteen young adult healthy female goats weighing 20-25Kg were included in the study. Animals were divided into 3 equal groups (n=6 in each): group I(control), while group II and III (the experimental groups). All animals of group II, III were subjected to unilateral mandibular body lengthening of the right mandibular side by distraction osteogenesis through the use of custom made stainless steel distractor. Distraction was performed at a rate of 2 mm per day for five days and a consolidation phase for four weeks. Animal sacrifice was performed post consolidation phase by one month in group II and by 6 months in group III. All temporomandibular joints were evaluated radigraphically for joint spaces evaluation and histologically for detection of changes in Joint architecture. The measured Joint spaces were subjected to statistical analysis. Results: Statistical analysis showed that comparing changes in measurements of Joint spaces between different groups revealed no significant differences. Evaluation of histological changes in Temporomandibular joint(TMJ) revealed that in group II mild inflammatory and degenerative changes were detected. All these changes were within the adaptive capacity of the joints as; all these changes were mostly reversible in group III (6 months post consolidation). Conclusion: The results of the present study showed that mandibular unilateral lengthening by distraction osteogenesis at a rate of 2 mm per day may lead to initial mild inflammatory and degenerative changes in TMJ. However, all condyles showed adaptive and remodeling signs within 6 month period post consolidation. [Elsagaly A.H., Abd Elmonem K., Metwalli S.A., and Elkasaby M. Influence of rapid unilateral mandibular lengthening by distraction osteogenesis on the temporomandibular Joint (An experimental study). J Am Sci 2013;9(12s):1-10]. (ISSN: 1545-1003). http://www.jofamericanscience.org. 1 Key words: Osteogenesis, Condyles, Mandibular unilateral lengthening