Construction of a 3D finite element model of temporomandibular joints including the musculoskeletal system / 医用生物力学

Objective To discuss the feasibility of constructing a 3D finite element model of the temporomandibular joint (TMJ) including the musculoskeletal system based on imaging and anatomy, and to provide new ideas of modeling for TMJ biomechanical researches. Methods CT images of the skull, MRI images of masticatory muscles and bilateral TMJ from No.23 Chinese virtual human in the second generation were collected and imported in batches into Mimics in format of DICOM for 3D reconstruction. Then the model was integrated and optimized by Geomagic Studio, and the TMJ capsule and articular cartilage were also constructed. After the material properties of TMJ tissues were defined, a 3D finite element model of TMJ including the musculoskeletal system was finally constructed by ANSYS. Results The 3D finite element model of TMJ with the musculoskeletal system was constructed, including TMJ disc, articular cartilage, TMJ capsule, maxilla (including zygoma and nasal), mandible, sphenoid, temporal bones (including part of parietal), maxillary teeth, mandibular teeth, temporalis muscles, masseter muscles, medial/lateral pterygoid muscles, temporomandibular ligaments, sphenomandibular ligaments and sylomandibular ligaments. Conclusions Based on CT and MRI images and anatomy, the 3D finite element model of TMJ including the musculoskeletal system can be precisely and feasibly constructed by Mimics, Geomagic Studio and ANSYS. This model can restore the biomechanical environment of the TMJ, provide new ideas of modeling for biomechanical researches on the TMJ, and offer the simulation platform for visualization treatment of TMJ disease in clinic.

Infections of the head and neck leading to descending necrotizing mediastinitis: management of 9 cases / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To report nine cases of descending necrotizing mediastinitis (DNM) and to summarize the management experience.</p><p><b>METHODS</b>Between December 2005 and December 2008, nine patients (mean age, 55.7 years; age range, 38 to 78 years) with DNM were treated. Eight patients underwent surgical drainage of the involved cervical region and mediastinum (4 with cervical drainage alone; 4 with cervical drainage and right thoracotomy).</p><p><b>RESULTS</b>Two patients died, one of them refused surgical therapy and the other one died of multiorgan failure related to postoperative septic shock. Seven patients recovered. The mortality rate was 22%.</p><p><b>CONCLUSIONS</b>Delayed diagnosis and inadequate drainage are the main causes of high mortality rate of DNM. Aggressive surgical drainage and debridement of the neck and mediastinum by a multidisciplinary team of surgeons are very important in the treatment of DNM.</p>

Application of parasymphyseal mandible osteotomy combined with set-back tongue flap in treatment of tongue base carcinoma / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To evaluate the efficacy of the approach of parasymphyseal mandible osteotomy combined with set-back tongue flap in treatment of tongue base carcinoma.</p><p><b>METHODS</b>In total 18 patients with cancer of tongue base, 13 were males and 5 females aged of 30 to 65 y (average 52.9 y). Eighteen patients were treated by parasymphyseal mandible osteotomy combined with set-back tongue flap in our hospital from June 2001 to June 2006.</p><p><b>RESULT</b>The range of follow-up period was 2 to 5 years. All patients had satisfactory speech, swallowing and taste function.</p><p><b>CONCLUSION</b>Parasymphyseal mandible osteotomy provides good exposure, and set-back tongue flap to reconstruction of the base of tongue can partially restore the function of tongue.</p>