The Clinical Research Of Rigid Internal Fixation On Midface Fractures

Object: To discuss the application of rigid internal fixation (RIF) on midface fractures and provide the theoretical foundation and clinical guidance for the rigid internal fixation on midface fractures.Methods: 220 patients with midface fractures treated by rigid internal fixation with titanium mini plates and titanium micro plates were chosen from the patients treated in the Department of Oral and Maxillofacial surgery, Tianjin Medical University General Hospital from 1991 to 2006. The patients were analyzed according to age, gender, cause of injury , position of fracture, accompanying systemic injuries, operative approach, setting of titanium plates,inter maxillary fixation, postoperative occlusion, postoperative complication and so on. Then, the data were input Excel database, and displayed by statistic chart. We analyzed the data and then discussed as follows.Results: Among the 220 patients, the maxillary fracture was the most popular, at a rate of 39.09% in all, and the most of associated systemic injuries was mandibular fracture. Among this group of patients, the upper vestibule incision was used most extensively, at a rate of 32.73% in all approachs, the next approach was the combining with interoral and extraoral incision, at a rate of 32.27% in all. The titanium plates was always placed at the site of vertical and horizontal brace such as:zygoma-alveolar, zygoma-frontal brim,suborbital edge,zygomatic arch and pear-shaped aperture et al. 351 pieces of micro plate and 267 pieces of mini plates were applied in all patients In our study, the more miniplates were applied in maxillary fractures and the more microplates were applied in zygomatic, orbital, and naso-orbital-ethmoid (NOE) fractures. In this group, 104 patients were treated by intermaxillary fixation postoperatively, the rate was 42.27%. There was significant difference in the rate of intermaxillary fixation between the group of fresh fractures and staled ones, the group companying mandibular fractures and non-company ing mandibular fractures, and the group of maxillary fractures and zygomatic complex fractures, (P<0.05) .There was significant difference in the occlusion recovery between the group of fresh fractures and the staled ones by the fourth week after operation. (P<0.05) ,and by the first day and the fourth week afer operation there was significant difference between the group of companying mandibular fractures and that of non-companying mandibular fractures. By the fourth week after operation, the degree of open mouth of 202 patients was larger than 2cm,that of 99 patients was larger than 3 cm. In the group of non-intermaxillary fixation, the rate of normal degree of open mouth was 60.34%,whereas the rate was only 27.88% in the group of intermaxillary fixation. Infection was popular complication in RIF of midface fractures, there was significant difference between the group of 1 -2 pieces of plates applied and that of 3-7 pieces of plates. There was more opportunity of infection in the group of 3-7 pieces of plates applied. In addition, the complication of RIF of midface fratures also include suborbital nerve injury, occlusal interference, etc. 218 patients acqired ideal face profile.Conclusion: RIF has the advantages over conventional intermaxillary fixation, in the stability of fracture fixation, the recovery of occlusion, the degree of open mouth and the face profile. It is essential for the fracures of multiple, comminuted and staled treated by RIF together with intermaxillary fixation to achieve perfect effect. The upper vestibule incision, the combining interoral incision with extraoral incision were the approach widely used in midface fracture. The principle should be abided that the vertical and horizontal braces were restored with the titanium plates. Infection should be avoided and occlusal interference should be reduced.