• Wandee Apinhasmit
• Dolly Methatharathip
• Somporn Swasdison
• Suchart Kanwasukul

Objective  The aim of this study was to investigate the relationship between the occurrence of torus palatinus (TP) and torus mandibularis (TM) and numbers of teeth in a group of Thais.

Material and Method  One thousand three hundred and fifty subjects were clinically examined for the presence of both tori at the Faculty of Dentistry, Chulalongkorn University. Numbers of the present teeth, sex and age of each subject were recorded. The subject were divided into six age groups: 13-19, 20-29, 30-39, 40-49, 50-59 and 60 years and over. The relationship between both tori and numbers of teeth was studied by comparing the differences of numbers of teeth in the subjects with and without both tori. The differences between groups were analyzed by using Mann-Whitney U test. Significance of the differences was set at p<0.05.

Results  The results showed that average numbers of upper teeth in total subjects with and without TP were not different (p = 0.974). Average numbers of lower teeth were higher in total subjects with TM than those without TM (p = 0.001). According to gender, only in males with TM have average numbers of lower teeth more than those without TM (p = 0.010). In addition, numbers of lower tooth lost in males with TM were lower than those without TM (p = 0.010). When the age was concerned, the differences between average numbers of upper teeth in subjects with and without TP existed only in the group of 60 years and over. Average numbers of lower teeth in subjects with and without TM were different in the subjects over 30 years of age except in 40-49 year age group.

Conclusion  There is a relationship between the occurrence of TM with lower teeth in total subjects and in males.
(CU Dent J 2002;25:203-9)