Potential factors influencing the development of oral tongue squamous cell carcinoma in young mature patients: Lingual position of the mandibular second molar and narrow tongue space.

The lingual position of the mandibular second molar and narrow tongue space are associated with oral tongue squamous cell carcinoma (OTSCC) development in young mature patients. The present study aimed to assess the role of the mandibular second molar position and tongue space in young mature patients with OTSCC. The medical records of 21 patients with OTSCC aged <50 years, who had an intact mandibular second molar and had undergone computed tomography (CT) imaging between April 2009 and December 2015 at the Section of Maxillofacial Surgery in Tokyo Medical and Dental University, were retrospectively examined. As controls, 21 sex-matched patients of a similar age to the patients in the OTSCC group, and with a height and weight within 5% of those of the OTSCC group, were collected. The location of the mandibular second molar on the affected side and area of the tongue space were determined using coronal and axial CT images. Mann-Whitney U test analysis revealed that the location of the mandibular second molar and the area of the tongue space differed significantly between young mature patients with OTSCC and the controls. The present study thus revealed that the lingual position of the mandibular second molar and the narrow tongue space may be potential factors influencing OTSCC development in young maturity.