Predictors of mandibular involvement in cancers of the oromandibular region.
OBJECTIVE
Invasion of the mandible by oral squamous carcinoma is not only a relative contraindication to mandible conservation but also an indicator of poor prognosis. This study looks at clinical, radiologic, and operative variables that may help in predicting mandibular bone involvement.


METHODS
A prospective study was carried out to evaluate the mandibular involvement and its predictors in 51 cases of oral squamous carcinoma located in the mandibular region. All patients underwent segmental- or hemimandibulectomy. A detailed clinical examination was followed by radiologic assessment and operative assessment. Statistic analysis was carried out by chi(2) test (odds ratio [OR] with a significance level of 5%). Multivariate analysis was carried out by logistic regression analysis.


RESULTS
Univariate analysis identified location of tumor on lower alveolus (OR = 8.5), sensory disturbances of inferior alveolar nerve (OR = 16.2), location of tumor within 1 cm of mandible (OR = 1.4), presence of findings on periosteal striping (OR = 2.0) like subperiosteal reaction (OR = 3.5), cortical expansion (OR = 8.8) and presence of pathologic fracture (OR = 2.3) as predictor of bone invasion. Grade of tumor (P = .05) and radiologic bone involvement (P = .02) were found to be significant independent predictors of pathologic bone involvement on multivariate analysis.


CONCLUSIONS
It is possible to identify mandibular invasion in almost all cases of oral squamous carcinoma by combining clinical examination, radiologic findings, and findings on periosteal stripping. This helps surgeons to make an informed preoperative and intraoperative decision about mandibular conservation. However, one should be careful when evaluating bone involvement on periosteal stripping as this cannot be recommended as a method of choice due to fear of tumor dissemination and violation of oncologic principles.
Pandey
Manoj
M
Department of Surgical Oncology, Regional Cancer Center, Medical College, Trivandrum, India. manojpandey@vsnl.com
Rao
Latha P
LP
Das
Shaima R
SR
D002294:Carcinoma, Squamous Cell / Q000473:pathology* / Q000601:surgery; D005260:Female; D006801:Humans; D008297:Male; D008334:Mandible / Q000473:pathology* / Q000601:surgery; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000473:pathology* / Q000601:surgery; D009361:Neoplasm Invasiveness; D011379:Prognosis