OBJECTIVE: To establish the animal models of mandibular distraction osteogenesis in rabbits and study its osteogenetic mechanism. METHODS: The right mandibles just anterior to the first molars of 12 rabbits were performed osteotomies, and the mandibles were positioned with distractors. The left mandibles were control group without operation. After 1 week, the distractors were stretched 0.9 mm every day for 10 days progressively. One day, 2, 4, 8 weeks after distraction, the mandibles were studied with gross measurement, X-ray, and histological examination. RESULTS: The right mandible were lengthened 8.3 mm on average without bone nonunion and deformity healing. It was observed that the gaps between the distracted bone edges were first occupied by fibrous tissue. Two weeks after distraction, it was found that the gaps were bridged by callus in X-ray, the new bone and the normal bone could not be differentiated clearly after 8 weeks. In histological sections, there were collagen bundles in early distraction, then those collagen bundles were calcificated and become trabeculaes. No Cartilage was found during distraction. CONCLUSION: It suggests that the rabbit mandible can be lengthened by distraction osteogenesis, and the new bone is formed by intramembranous ossification.
【Abstract】 Objective To assess the feasibility and clinical outcomes of artificial condylar process in reconstruction of the temporomandibular joint. Methods Between January 2005 and January 2010, the reconstructions of the temporomandibular joints with artificial condylar process were performed in 10 cases (11 sides, including 7 left sides and 4 right sides). There were 7 males and 3 females with an average age of 50 years (range, 40-68 years). Mandibular condyle defects were caused by mandible tumor in 7 patients with a mean disease duration of 15 months (range, 9-24 months) and by bilateral condylar fractures in 3 patients with the disease duration of 2, 3, and 2 days respectively. According to Neff classification, there were type M and A in 1 case, type M and B in 1 case, and type M in one side and subcondylar fracture in the other side in 1 case. Results Incisions in all patients healed by first intention, and no complication occurred. All cases were followed up 1 to 4 years, showed facial symmetry and good occluding relation, and the mouth opening was 22-38 mm (mean, 30 mm). No temporomandibular joint clicking or pain and no recurrence of tumor were observed. Most of the artificial condylar process were in good position except 1 deviated from the correct angle slightly. All the patients could have diet normally. Conclusion The results of temporomandibular joint reconstruction after tumor resection with artificial condylar process are good, but the clinical outcome for intracapsular condylar fracture is expected to be further verified.
Objective To systematically review the efficacy of poly-L-lactide (PLLA) material treatment versus titanium plates treatment for mandibular fractures. Methods We searched the Cochrane Library, PubMed, Embase, Chinese Journal Full-text Database, VIP Database, and Wanfang Database to collect literatures about randomized or non-randomized controlled trials using PLLA treatment (the trial group) versus titanium plates treatment (the control group) for mandibular fractures in the last ten years (from January 2007 to March 2017). The quality evaluation and data extraction were carried out by 2 reviewers independently and analyzed by Review Manager 5.3 software. Results A total of 8 literatures including 453 patients with mandibular fractures were included in this Meta-analysis. There was no significant difference in total complications between the two groups [odds ratio (OR)=0.98, 95% confidence interval (CI) (0.55, 1.75), P=0.95], including dislocation healing [OR= 0.96, 95%CI (0.46, 2.01), P=0.90], occlusal disturbance [OR=1.53, 95%CI (0.61, 3.87), P=0.37], infection [OR=0.63, 95%CI (0.23, 1.74), P=0.37], and secondary operation [OR=0.46, 95%CI (0.17, 1.27), P=0.14]. Conclusion There is no significant difference between PLLA and titanium plate in the treatment of mandibular fractures.
目的 探讨多层螺旋CT对下颌骨骨折的诊断价值。 方法 对2007年4月-2009年10月下颌骨不同部位骨折的45例患者进行多层螺旋CT轴位扫描，并行多平面、表面遮盖法等三维重建，对下颌骨骨折CT表现特征作回顾性分析。 结果 45例下颌骨骨折中，位于下颌体骨折24例，下颌角骨折5例，下颌升支骨折6例，髁部骨折13例，冠突骨折2例；颞下颌关节脱位中，单侧脱位3例，双侧脱位5例。 结论 多层螺旋CT能准确诊断下颌骨各部位骨折，对诊治方案具有重要价值。
Objective To investigate the mode and influential factor of newbone formation following distraction osteogenesis in mandibular lengthening. Methods Corticotomy was performed on bilateral mandibles in twelve adult male goats. A custommade distractor was used to lengthen the mandible at a rate of 1mm/day for 10 days (total 10 mm elongation). Four goats were sampled respectivelyat 2, 4 and 8 weeks after completion of distraction. The lengthening mandibles were examined by roentgenography and histology. Results Newly formed callus was observed in the distraction gap after mandibular lengthening. The new bone exhibited intramembranous ossification generally, but cartilage islands could be found in the specimen that diastractor loosed. Conclusion The above findings indicate that the mode of new bone formation in mandibular lengthening following distraction osteogenesis appears to be intramembranous ossification and that endochondral ossification takes place in case distractor has loosened.
Objective To evaluate the reliability and effectiveness of a deep circumflex iliac artery based iliac-internal oblique musculofascial chimeric flap (DCIA-IIOF) in reconstruction of complex oromandibular defect. Methods Between January 2010 and December 2015, DCIA-IIOFs were used to repair complex oromandibular defects in 11 patients. There were 8 males and 3 females, with an age of 27-75 years (median, 56 years). Original disease was lower gingival squamous cell carcinoma in 7 cases (T3N1M0 in 2 cases, T3N2M0 in 1 case, T4N0M0 in 2 cases, and T4N2M0 in 2 cases), osteoradionecrosis after radiotherapy for nasopharyngeal carcinoma in 2 cases, central mandibular squamous cell carcinoma in 1 case (T4N0M0), and mandibular malignant fibrous histiocytoma in 1 case. The length of mandibular bone defects ranged from 7 to 10 cm (mean, 8 cm), and the area of the mucosal defects ranged from 5 cm×3 cm to 7 cm×4 cm. Preoperative ultrasonic identification of the DCIA and its ascending branch was routinely performed. The DCIA-IIOF was harvested by using an anterograde dissection technique, of which the iliac island was used for segmental mandibular defect repair and the musculofascial island for soft tissue and mucosal defect repair. Results All 11 cases were followed up 15-75 months (median, 37 months). All flaps survived after operation, without necrosis of both iliac island and oblique internal musculofascial island. One patient had a mild submandibular infection which healed after wound drainage and intravenous antibiotics. At 1 month after operation, the color and texture of the musculofascial island were similar to oral mucosa without contracture, and the occluding relation was good for all patients. At 6 months after operation, the mouth opening hardly improved in 2 patients who had osteoradionecrosis; 1 patient who underwent postoperative radiotherapy had restriction of mouth opening; the remaining 8 patients had normal month opening and normal diet. Three patients died of cancer recurrence, 2 patients died of other diseases (encephalorrhagia in 1 case and myocardial infarction in 1 case), and the others survived without recurrence during follow-up. No patient developed abdominal hernia during follow-up. Conclusion DCIA-IIOF is a reliable flap in reconstruction of complex oromandibular defects. The occluding relation after operation is good and the mucosal lining is soft. This technique provides an effective option for moderate complex oromandibular defects repair.
ObjectiveTo systematically review the survival rate of different vascularized bone flaps in mandibular defect repair and reconstruction by Bayesian network meta-analysis. MethodsThe PubMed, EBSCO, Scopus, Web of Science, Cochrane Library, WanFang Data and CNKI databases were electronically searched to collect clinical studies related to the objectives from inception to February 2024. Two reviewers independently screened literature, extracted data and assessed the risk of bias of the included studies. The Bayesian network meta-analysis was carried out applying R software. ResultsA total of 24 studies involving 1 615 patients were included. The results of meta-analysis showed that the respective survival rates of fibula free flap (FFF), deep circumferential iliac artery flap (DCIA), scapula flap, and osteocutaneous radial forearm flap (ORFF) were 95.62%, 94.09%, 98.16%, and 93.75%. Moreover, the network meta-analysis failed to show a statistically significant difference between all comparators. Conclusion Current evidence shows that different vascularized bone flaps have similar survival rates in mandibular defect repair and reconstruction. Due to the limited quality and quantity of the included studies, more high quality studies are needed to verify the above conclusion.
Objective To investigate the application of rigid internal fixation in mandibular reconstruction with autogenous bone and to evaluate its efficacy. Methods From January 1994 to May 2004, 98 patients with mandibular defect received mandibular reconstruction with autogenous bone by using rigid internal fixation. Seventy-two cases of benign tumor and 26 cases of malignant tumor were included. Four hundred and ono rigid fixation plates were inserted.The clinical results and X-ray films were analyzed and the healing processes were evaluated. The functional and aesthetic results of the mandibular reconstruction were also evaluated according to Lopez assessment system. Results After a follow-up of 1 to 3 years, 95 patients（96.9%）achieved successful effect. The forms and function of the mandibleswere resumed. Eightyone （82.7%）patients were satisfied with the results ofoperations. Thirteen patients（13.3%） achieved acceptable results. Four patients (4.1%) were dissatisfied with the results of operations. Conclusion The rigid internal fixation is conductive to healing and remodeling ofthe transplant bone in mandibular reconstruction.
OBJECTIVE To study the anatomical basis of vascularized spina scapular bone flap, which was used in mandibular reconstruction. METHODS Fifteen adult cadavers were adopted in this study. The two common carotid arteries of each cadaver were intubed and perfused with red emulsion respectively. Then the course and distribution of the transverse cervical artery(TCA) and its spina scapular branches were observed on 30 sides. RESULTS The TCA was divided into two segments: the cervical segment originated from the origin of the artery to the superior margin of the trapezius muscle, and the dorsal segment originated from the superior margin of the trapezius muscle to the site where the TCA bifurcated into the superficial and deep branches. The average length and original caliber of the cervical segment were(4.7 +/- 0.1) cm and (4.0 +/- 0.1) mm. The average length and original caliber of the dorsal segment were (5.88 +/- 0.63) cm and (3.30 +/- 0.35) mm. 86.7% spina scapular branches originated from the superficial branch of TCA and 13.3% from TCA. The length of the spina scapular branch was (4.97 +/- 1.68) cm and its external diameter was (2.08 +/- 0.27) mm. It constantly sent 4-8 periosteal branches to spina with 0.20-1.25 mm in caliber. CONCLUSION The spina scapular branch of TCA is one of the main blood supplier to the spina scapular area. The spina scapular flap pedicled with spina scapular branch of TCA may provide a new operation for mandibular reconstruction, whose circumpoint locates at the origin of the dorsal segment and the average length of the pedicle is 10.85 cm which enough to transposite to mandibular area.
Objective To investigate the method of combining radial forearm free flap and adjacent tissue flap in reconstruction of palatomaxillary defects and its effectiveness. Methods Between March 2005 and May 2010, 17 patients with palatomaxillary defects were treated. There were 11 males and 6 females with an age range of 45-74 years (mean, 62.5 years), including 1 case of benign tumor and 16 cases of malignant tumors (7 cases of squamous cell carcinoma of palate, 1 case of recurring squamous cell carcinoma of palate, 1 case of malignant melanoma of palate, 1 case of adenoid cystic carcinoma of palate, 1 case of malignant melanoma of maxilla, 1 case of ductal carcinoma of maxilla, and 4 cases of squamous cell carcinoma of maxilla). The maxillectomy defect ranged from 7.0 cm × 5.5 cm to 10.0 cm × 7.5 cm. According to Brown’s classification for the maxillectomy defect, there were type II in 15 cases, type III in 2 cases. Palatomaxillary defects were repaired with radial forearm free flap and buccal fat pad in 11 cases, and with radial forearm free flap, buccal fat pad, and mandibular osteomuscular flap pedicled with temporal muscle in 6 cases. The effectiveness was evaluated after operation by observing the vitality of the flap, the functions of speech, swallowing, breath, and the facial appearance. Results All cases were followed up 6-12 months without tumor recurrence. All flaps and skin grafts at donor sites survived. The functions of seech, swallowing, and breath were normal without obvious opening limitation. The facial appearance was satisfactory without obvious maxillofacial deformity. No enophthalmos occurred in patients with orbital floor and infraorbital rim defects. The patients had no oronasal fistula with satisfactory oral and nasal functions. Conclusion According to the type of palatomaxillary defects, it can have good early effectiveness to select combining radial forearm free flap and buccal fat pad or combining radial forearm free flap, buccal fat pad, and mandibular osteomuscular flap for repairing defects.