Rotated subcondylar process fracture in the growing animal: an experimental study in rats.
Unilateral, rotated subcondylar fractures were surgically induced in young rats under general anaesthesia. A decrease in body weight was observed in the fractured animals, with recovery at the end of the experimental period. A tendency of deviation of the mandible to the fracture side was noticed on axial radiographs, but without significant difference between experimental and sham-operated animals. Histological data initially demonstrated acute inflammation along the articular capsule and adjacent muscle fibres. Within 2 weeks, exuberant callus formation occurred. Neither devitalized bone ends nor intra-articular granulation tissue were seen. After 1 month, the temporomandibular joint presented characteristics of normality, with the condylar process centralized into the temporal fossa, interposed by the articular disc. These results were preserved after 3 months. We concluded that rotational subcondylar fractures in young rats heal by callus formation, with simultaneous and prompt repositioning of the condyle.
Luz
J G
JG
Department of Oral and Maxillofacial Surgery, School of Dentistry, University of São Paulo, São Paulo, Brazil.
de Araújo
V C
VC
D000818:Animals; D001168:Arthritis / Q000473:pathology; D001835:Body Weight; D016723:Bone Remodeling; D002146:Bony Callus / Q000502:physiology; D002356:Cartilage / Q000473:pathology; D005146:Facial Asymmetry / Q000473:pathology; D005500:Follow-Up Studies; D017102:Fracture Healing; D006128:Growth; D007091:Image Processing, Computer-Assisted; D017746:Joint Capsule / Q000473:pathology; D008335:Mandibular Condyle / Q000000981:diagnostic imaging / Q000293:injuries* / Q000473:pathology; D008337:Mandibular Fractures / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*; D018485:Muscle Fibers, Skeletal / Q000473:pathology; D009220:Myositis / Q000473:pathology; D010006:Osteoblasts / Q000473:pathology; D011859:Radiography; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D012399:Rotation; D013223:Statistics as Topic; D018709:Statistics, Nonparametric; D013704:Temporomandibular Joint / Q000473:pathology; D019224:Temporomandibular Joint Disc / Q000473:pathology