Reduction and screw fixation of condyle sagittal fracture / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the technique and clinical effect in the surgical reduction and screw fixation of sagittal condylar fractures.</p><p><b>METHODS</b>Open treatment was performed on 21 cases (23 condyles) with sagittal condylar fractures. The condylar fracture segment was reduced and fixed by screw (long screw or lag screw). The patients began the mandible movement exercise early after the operation, and follow-up was performed in the first half year after the operation.</p><p><b>RESULTS</b>Favorable results were obtained in all cases. Slight malocclusion was observed in 3 cases accompanied with mandible fracture, but normal occlusion was almost reestablished after one week of intermaxillary traction. The CT examination indicated the ideal condition of reduction and fixation of these condylar fractures. During the follow-up, the mouth opening was normal, and mandible movement and function was satisfactory.</p><p><b>CONCLUSIONS</b>The technique of reduction and screw fixation in condyle sagittal fracture can obtain stable reduction and fixation.</p>

Time effect of dentin matrix protein 1 and osteoclast expression during mandibular fracture healing in rats / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To study the expression of dentin matrix protein 1 (DMP1) and osteoclast in callus at different healing period of mandibular fracture in a adult Wistar rat model.</p><p><b>METHODS</b>The mandibular fracture model of Wistar rats at the left mandibular ramus was established. The callus in the fractured site and the normal mandible were amputated at the 5th, 7th, 14th and 21st day after the fracture. HE staining was used to observe the condition of fracture healing and TRAP staining used to observe the activation of osteoclast. The expression of DMP1 was detected in the callus by using immunohistochemical method.</p><p><b>RESULTS</b>The number of osteoclasts reached a peak from the 14th to 21st day. The expression of DMP1 became very active from the 7th to 14th day.</p><p><b>CONCLUSIONS</b>The expression of DMP1 and osteoclast during fracture healing exhibited time effect.</p>

The preliminary study on the characteristics of mandible and condyle in dentin matrix protein-1 gene knockout mice / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To study the characteristics of mandible and condyle in Dmp1 gene knockout mice, and to investigate the role of Dmp1 in the osteogenesis and mineralization of bone and cartilage.</p><p><b>METHODS</b>Dmp1-/-mice were executed at birth, 2 weeks, 2 months, 3 months and 5 months, and the mandible was taken out for physical, radiography, transmission electron microscopic, and histological examination. The difference between Dmp1 knockout mouse (ko) and wild type mouse (wt) in bone development, bone densitometry and histology were compared.</p><p><b>RESULTS</b>There were obvious changes in the mandible and condyle of Dmp1-/-mouse, such as incomplete ossification, low density, decreased volume and condyle cartilage degeneration.</p><p><b>CONCLUSIONS</b>Dmp1 is the key factor in the formation of growth plates and secondary ossification center, and plays an important role in the process of bone and cartilage formation and bone nodule remodeling. Dmp1 may be the candidate gene that controls the development of mandible and cartilage.</p>

Clinical study of surgical treatment of ankylosis of temporomandibular joint / 中华整形外科杂志

<p><b>OBJECTIVE</b>To analyze the clinical feature of temporomandibular joint (TMJ) ankylosis and to investigate the advantage and disadvantage of all kind of surgery methods of TMJ ankylosis for supplying references to the treatment of TMJ ankylosis.</p><p><b>METHODS</b>Aetiology, sex, age at time of treatment, clinical features, radiographic findings, surgical treatment was reviewed and analyzed.</p><p><b>RESULTS</b>Trauma (66.86%, n = 117) and infection (24.57%, n = 43) were the primary causes of TMJ ankylosis. The 10 approximately 19 years age group (44.57%, n =78) occupied the highest frequency in five age groups, one hundred and fourteen (65.14%, n = 114) of the patients presented with lateral ankylosis. They were carried out different surgery method according to their difference of age, aetiology, and so on.</p><p><b>CONCLUSIONS</b>The person at 10 approximately 19 years old had the more feasibility of TMJ ankylosis than others. Trauma was the commonest cause of ankylosis. Different surgical method should be choose according to the different patient.</p>

The orthognathic treatment of mandibular asymmetry / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the methods of orthognathic treatment for mandibular asymmetry.</p><p><b>METHODS</b>110 cases of mandibular asymmetry had been treated in past thirteen years. The type of deformity, the management of the cases, and the effects of orthognathic treatment were summarized in this paper. Orthodontic therapy was taken before and after operation to keep the treatment effect.</p><p><b>RESULTS</b>According to the type of the asymmetry deformity, different methods were used. After treatment, all the patients obtained satisfactory facial appearances and oral function.</p><p><b>CONCLUSION</b>It should be diagnosed before surgery whether the development of deformity is steady or not. If it is steady, the effects of orthognathic and orthodontic therapy will be satisfactory; if not, we should remove the affected condyles and simulataneously ameliorate facial appearance.</p>

Function of disk reposition in the treatment of traumatogenic temporomandibular joint ankylosis / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the method and results of disk reposition in the treatment of traumatogenic TMJ ankylosis.</p><p><b>METHODS</b>In 19 cases of traumatogenic ankylosis of TMJ, the dislocated disks were repositioned during anthroplasty. In the operation, the dissection of dislocated disk was performed carefully around the TMJ. The disk was repositioned to its anatomic location over the top of condylar stump, then the lateral aspect of the disk was sutured to the soft tissue of zygomatic root.</p><p><b>RESULTS</b>At the last follow-up examination, interincisal opening distance ranged from 24 to 43 mm in all cases (mean 32.63 mm), which approached or reached the normal level. No recurrence and TMJ symptom were found during the period of follow-up.</p><p><b>CONCLUSIONS</b>The disk repositioning in treatment of traumatogenic TMJ ankylosis is a feasible and effective approach to reconstruct the structure and function and prevent recurrence.</p>

A clinical investigation on the surgical approach and fixation in operative treatment zygomatic fractures / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the effect of soft tissue incision and rigid internal fixation in the treatment of zygomatic fracture.</p><p><b>METHODS</b>70 cases with zygomatic fracture were entered into the study. The clinical data of 65 patients who were performed operations in the treatment were analyzed. The study focused on the incision, number and locations of Titanium plate. The facial contour, reduction,fixation, healing of incision, facial bisymmetry and complications of the operation were followed up 3 - 24 months after surgery.</p><p><b>RESULTS</b>All the incisions were primary healing. Clinical and radiologic assessment of reduction was symmetric and stable in 91.5% of all cases, asymmetric in 8.5% of all cases. Subcutaneous hematoma happened in 5 cases, Ti plate exposure 1 in case, scalp scar width was more than 0.5 cm in 6 cases, frontal part or scalp paresthesia 8 cases.</p><p><b>CONCLUSIONS</b>Coronal scalp incision has advantages such as good exposure, precise removal of the bone block and good symmetry of both sides. RIF can improve the stability of fracture, promotes fracture healing and guarantees the rehabilitation of zygomatic complex. direct reduction and rigid internal fixation with Titanium microplate or miniplate are satisfactory in zygomatic fracture.</p>

Mandibular fracture fixed with PDLLA/nano-HA compound plates: an animal study / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the applicability of PDLLA/nano-HA compound plates used in internal fixation of mandibular fractures.</p><p><b>METHODS</b>Rabbit mandibular fracture model was used in this study. Clinical observation, the amount of callus, histological observation were studied and compared with PDLLA plates.</p><p><b>RESULTS</b>All fractures were fixed rigidly. There was 1 animal experienced local inflammation and then forming fistula in the side of PDLLA plate at postoperative 2 and 3 weeks. No side-effects were found in the side of compound plates. During the early stage of bone healing, the quality of callus in the side of compound plates was apparently more than that in the other side, and histological study showed that the osteoblasts and fibroblasts were more active in the side of compound plate in the early healing stage.</p><p><b>CONCLUSIONS</b>PDLLA/nano-HA compound plate has a proper degradation time. Compared with PDLLA plates, it is more effective and safer when used in mandibular fracture.</p>

Management of disk displacement with condylar fracture / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate clinical features of disk displacement during the course of condylar fracture and to explore the techniques of disk reposition and suturation.</p><p><b>METHODS</b>32 patients (10 females and 22 males) who had disk displacements with condylar fractures were followed up. Reduction and reposition of the dislocated disks simultaneously with fixation of fractures were performed. 7 patients underwent intermaxillary fixation with elastic bands for 1 to 2 weeks.</p><p><b>RESULTS</b>The occlusions were satisfactory in all cases but one for the reason of ramus height loss. No TMJ symptom was found when examined 3 months post operation.</p><p><b>CONCLUSIONS</b>Anterior disk displacements were most occurred with high condylar process fractures. Surgical reposition and suturation of disk play an important role for the later TMJ-function.</p>