Image-based quantification of alveolar bone

Abstract

Diminished alveolar bone support is the principal cause of tooth loss. This bone loss is most commonly attributed to periodontal disease. The causes of periodontal disease are not fully understood although bacteria in dental plaque are known to be major contributors. Moreover, it is thought that the incidence and prevalence of alveolar bone loss vary among human populations, hence identification of high-risk groups is essential to epidemiological studies aimed at establishing hypotheses about the etiology of alveolar bone loss. Data drawn from population surveys can then be used to test these hypotheses. Both epidemiological studies and laboratory and clinical testing have been hampered because of the lack of accurate methods for alveolar bone quantification. Recently, several noninvasive, image-based techniques, with accuracy sufficient for testing hypotheses concerning alveolar bone, have become available. The most commonly used of these methods are x-rays and dental radiographic films. We review the current methods for quantitative dental radiography, concentrating on digital techniques used in alveolar bone assessment. Although there is considerable potential to improve the imaging and quantifying of alveolar bone, current digital radiographic methods are practical for use by physical anthropologists and can provide information on bone mass variations among populations. Such information can be used to suggest and evaluate potential etiologic agents of alveolar bone loss. Moreover, these methods can be adapted to the quantitative measurement of image features (other than alveolar bone) that are of interest in anthropologic studies. The maintenance of a well-rounded, smooth alveolar crest with a n intact cortex results from an equilibrium between the formation and resorption of bone. When bone loss occurs, there is an absolute or relative increase in resorptive activity. This activity results in alterations in the alveolar bone. Cortical bone loss occurs through a n increase in cortical porosity and thinning while it appears that trabecular bone loss occurs through a decrease in the areaholume of the bone trabeculae (von Wowern, 1985(von Wowern, , 1986. Because of the lack of validated quantitative methods, the causes of alveolar bone loss have yet to be clearly identified although the presence and activity of bacteria in dental plaque are thought to be major contributors (Broadening the scope: Long-range research plan for the nineties: Na-