To evaluate the clinical effect of digital assisted chimeric deep circumflex iliac artery perforator flap (DCIAPF) in the reconstruction of mandibular composite defects. Methods From January, 2018 to January, 2019, 6 cases of mandibular tumor patients with postoperative defect within side were treated. Preoperative CTA was used to evaluate the deep branches of spin iliac artery.Digital simulation software and 3D printing technolo-gy was taken, vascularized iliac flap of the design guide of bone was made, and the rebuilding effect was simulated. DCIAPF was used to repair the defect of lower jawbone. The donor sites were sutured directly. The patients were fol-lowed-up in outpatient department for 3-6 months to evaluate the recovery of the patient′s shape, jaw height and oc-clusal function, as well as the complications in the donor area. Results Postoperation pathological examination re-sults: ameloblastoma in 2 cases, 4 cases of gingival cancer. The length of cut out ilium was 6.0-13.0 cm, carrying the flap area of 3.0 cm×1.0 cm-6.0 cm×5.0 cm.Six cases of DCIAPF and iliac bone flap survived.The shape, mandibular height and occlusal function were satisfactory.And no obvious complications were found in the donor area. Conclu-sion The blood supply of DCIAPF is rich with enough bone mass and height. The position of terminal skin perfora-tors is invariant. The complications of donor sites is less. With the help of digital technology, the accuracy of mandibular defect repair and the 3-dimensional wound repair can be realized, and provides an advantage condition for subsequent dental implant.It is one of the ideal method of reconstruction of mandibular defect.

Objective: To investigate the effect of elective neck dissection on the 5-year survival rate of patients with early oral squamous cell carcinoma. Methods: The data of 100 patients with early oral squamous cell carcinoma (cT1-2N0M0) were retrospectively analyzed. In 61 cases, the primary tumor was subjected to elective neck dissection (END). Neck observation and follow-up (NOF) were performed in 39 cases with enlarged resection of primary lesions. Clinicopathological data such as pT staging, pathology classification,the rate of cervical lymph node metastasis and the 5-year survival rate of the patients were statistically analyzed. Results: The 5-year survival rates of the END and NOF groups were 86.9% and 69.2%, respectively, and the difference was statistically significant (P=0.028). END treatment was significantly better than NOF in controlling cervical lymph node metastasis in early oral squamous cell carcinoma (P=0.009). After stratified analysis of histopathological features, the 5-year survival rate of patients with pathological T2 (pT2) stage OSCC in the END group was significantly higher than that in the NOF group (P=0.020). The 5-year survival rate of patients with moderate and poorly differentiated pathological grade OSCC in the END group was significantly higher than that in the NOF group (P=0.013). Conclusion END is effective for the management of the cervical lymph node metastasis rate in early OSCC patients. For patients with pT2 stage or low differentiation pathological grade, active END can significantly improve the 5-year survival rate.