Objective: To observe effects of treatment of mandibular fractures with compression or non compression internal fixation. Methods: In the in vivo study mandibular fractures were fixed by compression internal fixation on one side and non compression on other side in 15 dogs and observed radiologically and histologically. In clinical practice 42 patients with 58 mandibular fractures were treated with compression internal fixation, and 56 patients with 78 madibular fractures were treated with non compression internal fixation. Their clinical effects were evaluated by masticatory efficiency test, radiological and clinical observation after operation. Results: Primary bone healing was found histologically in group of compression fixation and bone healing through callus in group of non compression in the dogs. In the patients treated with compression internal fixation bone fracture line disappeared 1 week earlier and masticatory efficiency was heigher than in those with non comprission fixation. Conclusion: Both methods are all effective in the treatment of mandibular fractures. The miniplate is convenient in use and the indication is wide ranging. The compression plate can speed healing of mandibular fractures, but the operation is more strict technically.

OBJECTIVEThis investigation aimed at explore the total distribution of neuropeptide Y-like immunoreactive (NPY-LI) fibers and their changes post-trauma in rat temporomandibular joints (TMJs).

METHODSSix groups of rats were killed individually before trauma, 1, 3, 7, 14 and 28 days after trauma. TMJs were extracted totally, and the avidin-biotin-peroxidase complex method and image analysis were employed to detect NPY-LI fibers in frozen sections of TMJs.

RESULTSNPY-LI fibers were distributed extensively in TMJs, except the central disc band and bone, and they were mainly located around blood vessels, especially arteries. The densities of fibers in the six groups were 160.4 +/- 27.5, 95.8 +/- 16.4, 88.6 +/- 14.5, 114.3 +/- 17.0, 135.0 +/- 20.7, 158.6 +/- 19.5 (unit:mm2).

CONCLUSIONNPY-LI nerve fibers are distributed extensively in the periphery of blood vessels of TMJs and densities changed dynamically when TMJs were impacted. NPY may play an important role in pathologic change of TMJ by regulating local blood circulation.

Animals ; Male ; Nerve Fibers ; metabolism ; pathology ; Neuropeptide Y ; analysis ; physiology ; Rats ; Rats, Sprague-Dawley ; Signal Processing, Computer-Assisted ; Temporomandibular Joint ; innervation