Histological study on effects of lateral pterygoid muscle on condyle morphology reconstruction in healing process of sagittal fracture of condyle

Objective To discuss the effect of the lateral peterygoid muscle on reconstruction of condylar shape during healing process of sagittal fracture of mandibular condyle(SFMC).Methods Twenty four one-year-old adult sheep were randomly divided into 2 groups.All sheep were treated with osteotomy to make sagittal fracture of the right condyles.Anterior and posterior attachments of the the discs were cut and pushed inward.The pterygoids of sheep in group A were kept on the internal poles of the fractured condyles and their functions remained.The pterygoids of sheep in group B were cut,and their functions were blocked.Sheep in each group were sacrificed 2 weeks、4 weeks、12 weeks、and 24 weeks after surgery.Separate complete TMJ and observe them under a microscope.In sagittal direction of TMJ,fix them on the first third points in inside,outside and middle parts.Make HE staining and paucean trichrome staining.Result There was more new bone in group A where functions of lateral peterygoid muscles were kept,compared with group B.Change in condyle morphology was also more severe in group A.Conclusions Lateral pterygoid muscle plays very important role in reconstruction of condylar shape during healing process of sagittal fracture of mandibular condyle(SFMC),results to more new bone formation,even induce ankylosis.