Patterns of alveolar bone loss in Nigerian Yorubas.

Unusual patterns of alveolar bone loss in 33 Nigerian Yorubas with severe periodontal disease are described. The subjects, aged 15-50 yr represented 1.4% of a population of dental patients in Western Nigeria. Periodontal pocketing and alveolar bone loss in the incisor and first molar regions, far in advance of other mouth areas, were the criteria for inclusion in this report. Intra-oral radiographs showed advanced horizontal or crescentic bone resorption in incisor regions, and vertical or arc-like bone defects around first molars. Incisors and first molars were frequently missing as a result of periodontal disease. Surveys of tooth mortality and periodontal pocketing in Western Nigeria, and immunological findings elsewhere, suggest these cases represent a severe form of plaque-induced inflammatory periodontal disease. The role of protein-calorie malnutrition as an aetiological factor is discussed.