[Effect of collagen sponge on the healing process of alveolar fossa after tooth extraction in rats].

PURPOSE: To investigate the effect of collagen sponge on early bone healing process of alveolar fossa after tooth extraction in rats. METHODS: A total of 16 healthy female SD rats were selected. Animal models with tooth extraction were established. The right alveolar fossa inserted with collagen sponge was as the experimental group, and the left alveolar fossa was as the control group with treatment. The rats were sacrificed 1, 2, 4 and 8 weeks after tooth extraction, and the osteogenesis of alveolar fossa was observed. Real-time quantitative PCR (qt-PCR) was used to detect the changes of osteogenesis related gene expression. SPSS 19.0 software package was used for statistical analysis. RESULTS: After surgery, alveolar cavity healing was significantly better in the experimental group than in the control group. Osterix, Runx2 and Vegf genes were expressed in the experimental group and the control group, and the expression levels of related genes in the experimental group were significantly higher than the control group 1, 2, 4 and 8 weeks after surgery(P＜0.05). CONCLUSIONS: Collagen sponge could promote early alveolar bone healing, possibly related to the expression level of osteogenic genes regulated by collagen sponge.

[The effects of recombinant human growth hormone on mandibular bone loss with or without teeth in the ovariectomized rats].

PURPOSE: To investigate the effects of recombinant human growth hormone(rh-GH )on mandibular bone loss with or without teeth in the ovariectomized rats. METHODS: Three-month aged ovariectomized rats were utilized as postmenopausal osteoporosis models and all the molars in left mandibles were extracted. After operations, the rats began to receive rh-GH 1 mg.kg(-1).d(-1) with subcutaneous injection for ten days. Weight of the rats ,mineral density of the mandibular bone and 3 other parameters were measured at 8th week and 12th week. The data was analyzed with F and t test. RESULTS: The weight of the rats increased and mandibular bone mineral density of the rats were significantly improved after rh-GH treatment, P<0.05. CONCLUSION: Rh-GH can increase the weight of the old rats and restore mandibular bone mass in mandibles with or without teeth.

[Analysis of preoperative misdiagnosis causes in 26 cases of neurolemmoma].

PURPOSE: To improve the understanding of the diagnosis and treatment of neurolemmoma in maxillofacial region by summarizing its clinical features. METHODS: The preoperative misdiagnosis causes and treatment in 26 cases of neurolemmoma were reviewed. RESULTS: Among all cases treated surgically, 4 cases were pleomorphic adenoma of the parotid gland; 3 cases were malignant tumor of the parotid gland; 1 case was zygomatic osteoma; 4 cases were carotid body tumor; 1 case was branchial cleft cysts; 3 cases were cervical lymph node metastasis; 2 cases were pharyngeal malignant tumor; 4 cases were fibromatosis of the tongue; 2 cases were dermoid cyst; 2 cases were sublingual gland tumor. CONCLUSION: It is difficult to diagnose neurolemmoma before operation, however, it is important to carefully protect the function of the nerve in order to avoid severe complications.