ABSTRACT
<p><b>OBJECTIVE</b>To evaluate the degree and pattern of alveolar bone defect in aggressive periodontitis (AgP) using cone-beam CT (CBCT), and to investigate the distribution of alveolar bone defects in aggressive periodontitis.</p><p><b>METHODS</b>Forty AgP patients (age: 14-36 years, male: 15 cases, female: 25 cases) were selected by simple random method and scanned by CBCT. NNT software was applied to measure the average degree of alveolar bone defects and bone loss types in different regions.</p><p><b>RESULTS</b>In forty AgP patients, 86.6% (3,769/4,352) sites presented moderate and severe alveolar bone defects. In the maxilla, the molar areas presented the heaviest alveolar bone defect [(6.3±0.7) mm], the canine areas showed the lightest bone loss [(4.8±0.8) mm]. In the mandible, the incisal areas presented the heaviest alveolar bone defect [(5.9±0.9) mm], the canine areas showed the lightest bone loss[(5.1±0.7) mm]. The degree of alveolar bone defect in the areas of maxillary canine, maxillary molars, mandibular premolar was significantly different (P<0.05). The degree of alveolar bone defect in mandibular canine and mandibular molars was significantly differenct (P<0.01). The most serious alveolar bone defect was in the mesial side of maxillary molar [(6.9±0.7) mm] and the mesial side of mandibular incisor [(6.5±1.1) mm]. The oblique bone defects were found in the mesial part of the first molars in mandibula [13.6% (42/308)], the first molars in maxilla [12.0% (39/316)] and the first premolar in maxilla [10.8% (34/316)].</p><p><b>CONCLUSIONS</b>The alveolar bone defects of generalized AgP patients were serious. The most serious areas were located in the mesial side of maxillary molars and the mesial side of mandibular incisor.</p>