The Research Of Mandibular Invasion By Oral Squamous Cell Carcinoma

Objective: Comparing the different prognosis between marginal mandibulectomy(MG)and segmental mandibulectomy(SG)for oral squamous cell carcinoma retrospectively, so as to provide safety evidence of marginal mandibulectomy for some patients. To study the charaters of mandibule invaded by oral squamous cell carcinoma by two-dimensional serial sections and three-dimensional virtual reconstruction.Methods:1. 82 oral carcinoma operations involving mandibulectomy (ranged from January 2001 to June 2010)were evaluated by a nonrandom method retrospectively. Prognosis and recrudescent factors of MG and SG were compared simultaneously. 2. The specimens of invaded mandible were sliced buccolingually into serial sections and those sections stained by HE were scanned subsequently. The pathologic characters of those specimens were observed under microscope. Software 3D-DOCTOR was used to reconstruct and analyze virtual three-dimensional figure of mandible and carcinoma.Results:1.3-year and 5-year locally recurrent rate were 29.1%t and 39.7% in MG group, and 18.4%, 34.2% respectively in SG group. The locally recurrent rate between the two groups achieved no statistical significance(P>0.05). 3-year and 5-year survival rate were 75.2%t and 55.5% in MG group, and 69.2%, 60.7% respectively in SG group. There were no statistical significance between the two groups either (P>0.05). Low differentiated pathologic type was the only influent factor to the oral cancer in multivariate Cox regression analysis(P=0.001)and moreover,the follow up to these patients is of great importance. 2. Micrograph of the mandible which was shallow or moderate invasion showed limited bone involvement. The outline of the destroyed mandible was rather well defined and appeared to be smooth. There was dense fibrous tissue between the tumor and destroyed mandible. Micrograph of the deep bone invasion case showed infiltrative bone involvement. In this pattern of disease, fingers and islands of tumor advanced independently into the cancellous spaces, with no intervening layer of fibrous tissue. Stereo image of oral squamous cell carcinoma invading mandible could be shown satisfactorily. Every shape of stereo image and the structure of mandible could be shown by revolving the three dimensional image in different direction, beneficial to us in understanding the dimensional growth pattern of oral squamous cell carcinoma in mandible.Conclusions: According to the analysis of the experimental and clinical statistics, marginal mandibulectomy maybe worth a try in appropriate cases.