Relationship between oral tori and oral condition in Japanese adults

Objectives: The purpose of this study was to investigate the distribution of tori for various locations in Japanese adults and to estimate oral condition in relation to tori. Methods: The subjects were a total of 400 employees who worked in a toiletry company. They were 306 males aged 22 to 64, and 94 females aged 22 to 58. Torus was assessed by visual examination and digital palpation, and its length, width, and depth were recorded. Results: The prevalence of subjects with torus was 64.1% for men and 57.4% for women(p<0.05). With respect to maxillary tori, the prevalence of subjects with palatal torus was 7.2% for men and 23.4% for women (p<0.05) and 13.1 % of subjects with maxillary buccal torus. Also, the prevalence of subjects with mandibular lingual torus was 59.5% for men and 42.6% for women (p<0.01) and 3.0% of subjects had mandibular buccal torus. In those who have mandibular lingual torus, 70.3% had symmetrical torus(p<0.05), and 38.3% had connective torus(p<0.05). Most mandibular lingual torus occurred symmetrically and was isolated. From the multiple logistic regression analysis, the risk factors for mandibular lingual torus were gender (OR 0.47), number of sound teeth (OR 1.62), and bruxism (OR 1.72) and the palatal torus were gender (OR 4.43) and TMJ symptoms (OR 2.25). Conclusion: We could obtain the distribution of torus from Japanese adults, and the risk factors for palatal and mandibular torus associated with oral conditions. This study indicated that there were different risk factors between palatal torus and the other torus.