Morphologic Analysis Of Alveolar Bone In Maxillary And Mandibular Incisors On Sagittal Views

Objectives:The aim of this study was to analyze the morphologic features of alveolus in relatively healthy maxillary and mandibular incisors using cone-beam computed tomography(CBCT).Methods:CBCT images of31 8 patients(86 males and 232 females)were retrospectively acquired in Peking University Hospital of Stomatology from July 2015 to August 2016.Alveolar bone in incisive area was divided into:type 1(thick),type 2(relatively thick with mono-plate concavity),type 3(thin with double-plate concavities)and type 4(vulnerably thin).Alveolus types and root orientations were assessed,buccolingual width was measured.Alveolus prevalence and widths were analyzed statistically relative to age,gender,and molar relationship.Results:The prevalence of type 1 alveolus was 78.9%in maxillary central incisors and 15.1%in maxillary lateral incisors.Type 2 alveolus was commonly observed in the maxillary lateral incisors(82.2%).The prevalence of type 3 ridges ranged from 0.0%to 3.1%in maxillary incisors.As for type 1 maxillary central incisors,the alveolar ridge width and alveolar width in periapical area were 7.77±0.58 mm and 9.05±1.86 mm respectively.Type 1 was the widest both in the alveolar crest and periapical area,while type 3 had the lowest width in the apical region.Besides,buccal orientations were commonly found in maxillary incisors.Prevalence of type 1 alveolar ridge showed a tendency to decrease with age in maxillary central incisors.Type 1 occurred more frequently among maxillary lateral incisors in males than in females.Significant differences were found in the distribution of maxillary lateral incisors alveolus types among three molar relationships.The prevalence of type 1 alveolus was 24.1%in mandibular central incisors and 5.0%in mandibular lateral incisors.Type 2 alveolus was commonly observed in the mandibular central incisors(66.2%)and mandibular lateral incisors(87.9%).The prevalence of type3 and 4 ridges ranged from 0.5%to 9.4%in mandibular incisors.Midway orientations were commonly found in mandibular central incisors and mandibular lateral incisors.As for the mandibular incisors,the prevalence of type 1 alveolar ridge showed a tendency to decrease with age.Type 1 occurred more frequently among mandibular central incisors in males than in females.Significant differences were found in the distribution of mandibular incisors alveolus types among three molar relationships.Conclusion:A 4-type classification system was suggested for alveolus morphology in incisive region.Identification of alveolus type might aid in the corresponding treatment.