Morphological difference in the teeth and dental arch between the Nigerian and the Japanese

Abstract

To make clear the present situation of the dental disease among Nigerian children and adults, a longitudinal dental survey was jointly conducted from 1980-1991 by Obafemi Awolowo University, School of Dentistry, Ile-Ife, Nigeria, and a team of Japanese researchers. The survey was funded and supported by the Overseas Survey Grant in Aid for Scientific Research of the Ministry of Education, Science and Culture of Japan.
During the final survey in 1991. dental arch width and length and mesiodistal crown diameters of 68 Yoruba children [41 males and 27 females, Age: 3-6] and 64 Yoruba young adults [33 males and 31 females, Age: 11-23] were measured and compared with those of Japanese. The following results were obtained.
1. Nigerian deciduous dentition were larger than Japanese in size of all items of arches, showing a statistically significant difference in the arch length and mandibular dental arch width in both sexes.
2. Nigerian deciduous teeth were larger than those of Japanese except upper deciduous second molar.
3. The statistically significant differences were observed in the maxillary and mandibular arch width and length in all cases of both sexes, especially remarkable in dental arch length.
4. Nigerian permanent teeth were larger in mesiodistal diameter those that of Japanese in all teeth. Statistically significant differences were found for male's upper central incisor and canine, lower teeth except central incisor and female's all teeth.