Age-related disruption of the lamina dura: evidence in the mandibular horizontal incompletely impacted third molar.

Changes in the lamina dura are associated with dental diseases around the root of the tooth and with systemic diseases; however, the lamina dura below the crown of horizontal, incompletely impacted third molars has not been studied. Using orthopantomography, we studied the age of subjects with and without the lamina dura in 419 subjects. The participants were between the ages of 21 and 89 years. Mean age in men with the lamina dura was 30.29 +/- 9.92 and without the lamina dura was 47.64 +/- 16.32 (P < 0.0001), and in women with a lamina dura it was 29.65 +/- 8.19 and without a lamina dura 41.97 +/- 11.07 (P < 0.0001). To study the effect of aging, the relationship between the lamina dura and dental status was assessed in subjects over the age of 31 years. Alveolar bone resorption in the canine and the first molar of the ipsilateral mandible in subjects without the lamina dura was not significantly higher than in those with the lamina dura. There were no significant differences in the number of teeth lost, except in men, the number of treated teeth and the number of decayed teeth differed between groups. Disruption of the lamina dura was related to age, but with no alveolar bone resorption in the mandible.