Fixation Of Mandibular Osteotomies Research Articles

Temporomandibular Joint Disorders and Maxillomandibular Malformations

Even if the relationship between condylar position and/or temporomandibular disorders (TMDs) and dentofacial deformity is controversial in literature, several patients presenting malocclusion refer to pain and TMDs as the main trouble. There are also various opinions concerning the alterations or improvements of temporomandibular joint symptoms after orthognathic surgery. In agreement with the experience of Universität Würzburg, the purpose of this study was to evaluate the validity of splint technique to reproduce centric condyle positioning in bimaxillary osteotomy surgeries for the patients with skeletal-facial disorders and coexisting TMDs. The present study is based on a sample of patients with maxillomandibular malocclusion and coexisting TMDs who underwent bimaxillary osteotomy surgeries with splint technique. All patients underwent a protocol consisting of various steps: Pretreatment evaluation consisted of a questionnaire on subjective symptoms, clinical examinations, photographs of the occlusion, plaster casts, bite registrations, examination of the posture; instrumental examinations; panoramic, teleradiography, and cephalometric analysis; stratigraphy of TMD; and electromyography. Presurgical treatment consisted of therapy by modified Farrar splint associated with a pharmacologic therapy for the acute symptoms; orthodontic treatment associated with a global reeducation of the posture and a pompage of the masticatory muscles; and manufacturing of an occlusal splint in the most posterior asymptomatic position. Surgical treatment consisted of bimaxillary osteotomies performed after registering condyle position by a "repositioning" plate. The condyle position is guided by the intermaxillary fixation with the interposition of the occlusal splint. Surgery on maxillary is performed through Le Fort I osteotomy and fixation. Later, sagittal splint osteotomy of mandible is performed. Position of ramus and TMD complex is guided by the positioning of the plates modeled previously and fixed to maxillary and ramus in the same relationship registered with the splint. Finally, fixation of mandibular osteotomies is performed. Postsurgically patients underwent orthodontic treatment (to stabilize occlusal and articular changes) and physical therapy. After the end of treatment, stability of results was investigated with clinical, radiologic, and electromyographic valuations. The authors' experience suggests that, as in orthognathic surgery, identification of a correct condyle-fossa relationship (achieved by splint and repositioning plate) is essential to guide osteosynthesis after sagittal split osteotomy in patients affected by TMDs and ultimately affects the stability of the procedure.

Treatment of tripod fracture of zygomatic bone by N-2-butyl cyanoacrylate glue fixation, and its effects on the tissues

The standard treatment of zygomatic bone fractures is fixation by microplates or miniplates and screws today. It is very difficult to place plates and screws into thin bones or small bone fragments especially in the facial bones and bones adjacent to important structures. Cyanoacrylate is used as a hemostatic agent, an embolic agent, in retinal tears, in corneal ulcers, in fixation of mandibular osteotomies and in craniofacial surgery. N-2-Butyl cyanoacrylate is a form of cyanoacrylate which is bioabsorbable and biocompatible. It is easily applied to the tissues. We aimed to determine the effect of N-2-butyl cyanoacrylate in the fixation of displaced zygomatic bone fractures. We examined the histotoxicity and the effects on healing and foreign body reaction of N-2-butyl cyanoacrylate. Eight New Zealand white rabbits underwent zygomatic osteotomies bilaterally. The fractures on left sides of the rabbits were determined as study site and right sides as control site. Knight and North classification of zygomatic bone fractures were used and group 4 fractures were made bilaterally. Open reduction of fractures was performed bilaterally and N-2-butyl cyanoacrylate was applied only on left sides. No fixation was made on right sides representing the control group. Postoperatively in the first, second, third and fourth weeks, two rabbits were sacrificed and the fracture sites were examined macroscopically and histopathologically. In the glued study group, fixation was obtained in all cases whereas in the control group, all the fractures were seen to be displaced. Tissue reaction was similar in the study and the control groups.

Mandibular osteotomy fixed with biodegradable plates and screws: an animal study

The objective of the study was to evaluate the use of a totally biodegradable fixation device in the fixation of mandibular osteotomy in sheep. Mandibular unilateral body osteotomies were fixed with biodegradable self-reinforced poly-L-lactide (SR-PLLA) multi-layer plates and screws in nine sheep. The unoperated sides acted as control. The follow-up times were 6, 12 and 24 weeks, after which radiological, mechanical and histological studies were carried out. An analysis of the implanted material was also carried out. The results showed that the SR-PLLA plates and screws were strong enough to fix the osteotomy and that the osteotomies healed mainly with callus formation. Therefore we conclude that SR-PLLA multi-layer plates and screws can be used together successfully in the fixation of mandibular osteotomies without maxillomandibular fixation. However, before they can be used in humans, the size of the plate and screws should be decreased.