Biomechanical evaluation on prosthetic retention program for hemi-maxillary defects / 医用生物力学

Objective To make biomechanical evaluation on three prosthesis retention schemes for unilateral maxillary defects-clasp retention, one or two zygomatic implants and zygomatic implant and clasp united retention. Methods A three-dimensional (3D) finite element model of normal human skull was constructed based on CT scan data. The maxillary complex stress distributions on three reconstructed models were calculated and analyzed by 3D finite element method to make comprehensive comparison on stress level of the prosthesis, abutment, clasp, implants and zygoma. Results For single clasp retention, peak stress of the abutment was 130.7 MPa, and displacement of the prosthesis was 4.439 mm, while peak stress of the clap was 452.4 MPa, and stress of the contralateral orbital rim was 23.32 MPa. After one zygoma was implanted, the stress of the clap was reduced to 118.1 MPa, while peak stress of the abutment was 31.12 MPa, and stress of the contralateral orbital rim was only 5.387 MPa. For two zygomatic implant retention, zygomatic stress was decreased from 66.11 MPa to 48.12 MPa, and the maximum stress on the zygomatic implants was reduced from 500.2 MPa to 313.8 MPa. Conclusions For zygomatic implant and clasp united retention, the maxillofacial skeleton stress distributions were more consistent with the rules of bite force transduction. The research findings will provide important references for design and optimization of human unilateral maxillary defect reconstruction program.

Application of individualized free anterolateral thigh combined flap for tongue and mouth floor defects resulted from tongue carcinoma / 中华整形外科杂志

<p><b>OBJECTIVE</b>To investigate the application of individualized free anterolateral thigh combined flap (ALTCF) for tongue and mouth floor defect resulted from tongue carcinoma.</p><p><b>METHODS</b>From 2006 to 2008, individualized ALTCFs were used in 31 cases of tongue and mouth floor defects resulted from tongue carcinoma. The nutritional perforator vessel was musculocutaneous pattern in 22 cases and septocutaneous pattern in 9 cases. The size of the flaps and the included muscle was (4-8) cm x (5-10) cm and (2-5) cm x (3-6) cm, respectively. The length of blood vessel pedicle was (6.81 +/- 3.23) cm.</p><p><b>RESULTS</b>All the 31 free flaps survived with primary healing and no complication. The appearance and function were both satisfactory. During the follow-up period of 1-3 years, 28 cases survived, 2 cases were reoperated due to the neck lymphatic metastasis on the contralateral side. 1 case died of distant metastasis.</p><p><b>CONCLUSIONS</b>Individualized ALTCF is a reliable flap for the tongue and month floor defects resulted from tongue carcinoma. Both the cosmetic and functional results are satisfactory with less morbidity in donor site and less complication.</p>

Vascularized iliac crest graft with internal oblique muscle for immediate reconstruction of composite mandibular defect / 中华整形外科杂志

<p><b>OBJECTIVE</b>To evaluate the vascularized (deep circumflex iliac vessels) iliac crest graft with internal oblique muscle as a method for reconstruction of composite mandibular defect.</p><p><b>METHODS</b>Vascularized iliac crest graft with internal oblique muscle was used to reconstruct the composite mandibular defects in 10 patients. All clinical data were analyzed retrospectively. A detailed inspection of the case-notes was undertaken to ascertain the presenting diagnosis, the surgery, the complications and the outcome. The type of mandibular defect was recorded.</p><p><b>RESULTS</b>Of the 10 patients with composite mandibular defects including mandibular body, mandibular angle, mandibular ramus and the soft tissue around them, 7 patients were recorded with the defects of mandibular condyles. During the follow-up period from 3 months to 24 months, primary wound healing was observed in all patients, except one patient with minor muscular necrosis. All patients were satisfied with their facial contour and mandibular shape, without tumor recurrence. Donor site problems important enough to be recorded in the notes were minimal.</p><p><b>CONCLUSIONS</b>The vascularized iliac crest graft with internal oblique muscle offers a useful solution for reconstruction of composite mandibular defect. There is sufficient height and depth of bone to maintain a facial contour and mandibular shape. It can be used as a routine surgical technique to reconstruct composite mandibular defect.</p>