INTRODUCTION
Earlier studies on the causes of tooth morbidity and mortality among Nigerians and other African countries concluded that tooth loss was mainly due to periodontal diseases and dental caries, though dental caries was indeed to a lesser extent1.
Recent studies have shown that the incidence of caries occurrence is on the increase in many developing African countries as refined sugar, sweet and fruit drinks have become more readily available2. A National survey of dental caries status and treatment need in Nigeria reported a mean DMFT value of 0.7 1.3 and 2.5 for Nigerians aged 12, 15 and 35-45 years respectively.3 A more recent study reported a DMFT value of 2.00, 1.75, 1.45 and 1.00 in the children aged 12, 13, 14 and 15 years respectively in South-South geopolitical zone and a corresponding value of 2.38, 4.43, 3.19 and 2.57 respectively in the North Central geopolitical zone.4 Though the overall mean DMFT for North Central geopolitical zone ranges between 2.57 and 3.43 among the 12-15 years, it was reported that some children had a mean DMFT as high as 11-16 in the area.4 Though these reports showed a low dental caries prevalence in Nigeria, the disease still constitute a major public health problem because of the size of the population and the low treatment ratio reported in all age groups.3 Though the incidence and severity of dental caries have been reported in Africans recently, the incidence of caries among the various tooth types vary considerably. The morphology, time of eruption and positioning of the tooth in the oral cavity confers an inherent disadvantage/advantage to the various methods employed in the control of plaque and hence tooth decay/losses. A related study conducted in Ile-Ife Nigeria1 showed that the first molars accounted for 41.6% of all extractions due to caries, while the second molar accounted for 28.4%, third molar 14.5%, anterior teeth put together 3.8% and the premolars 11.8%.
The present study is aimed at identifying the tooth type most prone to caries and thus, to loss due to caries. The result will facilitate the development of an approach in treatments relevant to the problem and assist in addressing the oral health needs of the society1, thus minimizing tooth loss.
MATERIAL AND METHOD
Jos is the capital of Plateau State, which lies in the North Central geopolitical zone of Nigeria and has an estimated population of 853,445 as at 19985. The population is a conglomerate of various tribes of Nigeria with Berom, Jarawa and Angas as the
major ethnic group. The State Government has only one dental centre, which is complemented by one mission owned and few private dental clinics. Plateau State Government dental centre, by virtue of its location receives the majority of the patients.
Data was extracted, retrospectively, from case notes of patients who had extraction of permanent teeth for the management of dental caries and its sequalae, over the two year period January 2000 to December 2001. Other information like patients? biodata relevant to this study was also recorded. Approval for the study was obtained from Plateau State Hospitals Management Board. Data was analyzed using SPSS version 8 statistical package. Significance level was set at P = 0.05.