Mandibular radiomorphometric measurements as indicators of possible osteoporosis in postmenopausal women.

OBJECTIVE

The use of mandibular anatomic indicators on panoramic radiographs, i.e. the number of lost teeth, mandibular cortical width at the mental region (MCW), panoramic mandibular index (PMI), alveolar crest resorption degree (M/M ratio) and morphologic classification of the mandibular inferior cortex (MIC grade) can be useful in the evaluation of bone resorption in different age groups of women to determine the presence of osteoporosis. The purpose of this study was to assess the validity of mandibular radiomorphometric measurements and to determine the frequency of tooth loss in postmenopausal women.

SUBJECTS AND METHODS

An assessment of the number of lost teeth, MCW, PMI, M/M ratio and MIC grade was performed on dental panoramic radiographs in a group of 133 postmenopausal women 38-80 years-of-age. BMD at the lumbar spine was measured by dual energy X-ray absorptiometry. BMD values were categorized as normal (T-score greater than 1.0), and as indicative of osteopenia (T-score -1.0 to -2.5) or osteoporosis (T-score less than -2.5) according to the World Health Organization classification.

RESULTS

In our study when the T-score at the lumbar spine is decreased, the age of menopause is increased, and the MCW is decreased to a point of statistical significance. A decrease in MCW by 1mm increases the likelihood of osteopenia or osteoporosis to 43%, having taken into consideration the effect of the years elapsed since menopause. It was also shown that age, years since menopause, MCW value, and the number of teeth lost have a statistically important effect on the incidence of moderate or severe cortical erosion. Moreover, when the MCI is C2 or C3 (mild or severe erosions) the age is increased, the years since menopause are increased and the MCW is decreased to a point of statistical significance. As far as tooth loss is concerned, an increase by 1 unit in the number of teeth lost, increase the likelihood of moderate or severe erosion to 6%, having taken into account the years elapsed since menopause. Our study also demonstrated that postmenopausal women tend to lose their teeth at an age older than 50 years. They usually lose the 1st and 2nd mandibular molars and the 1st and 2nd maxillary premolars. Loss of front teeth and canines occurs at an age older than 60 years (except for the lateral maxillary incisors). At a younger age they tend to lose the 2nd maxillary premolars more frequently than their mandibular counterparts.

CONCLUSIONS

In conclusion, panoramic radiographs constitute an integral part of almost every routine dental evaluation and can be useful for the early diagnosis of osteoporosis in postmenopausal women. Dentists have sufficient clinical and radiographic information that enables them to play a significant role in patient screening for osteoporosis.