A CBCT measurement study on the thickness of the alveolar bone plate of the maxillary central incisors in elderly people

LU Chang; LIN Jiang

doi:10.19749/j.cn.cjgd.1672-2973.2025.06.009

Abstract：Objective To quantify the labial cortical thickness of maxillary central incisors in individuals aged≥60 years using cone-beam computed tomography(CBCT)and to provide an anatomical basis for risk assessment before immediate implant placement in the anterior maxilla.Methods From the radiologic archive of Beijing Tongren Hospital,120 CBCT scans containing the anterior maxilla were screened.After applying inclusion criteria(age≥60 years,intact labial tooth structure),100 subjects(200 maxillary central incisors)were enrolled.ITK-SNAP 3D reconstruction was performed,and the sagittal plane was standardized and extracted using Photoshop.The thickness of the labial bone plate at 1/2 of the root length,the root apex,1,3,and 5 mm apical to the alveolar crest,and 3 and 5 mm below the cemento-enamel junction(CEJ)was measured.The proportion of alveolar bone resorption and the total width of the labial and lingual diameters were also recorded.Results The thickness of the labial bone plate at 1/2 of the root length was 0.45(0.24,0.66)mm,with 92%being less than 1 mm and 57%less than 0.5 mm.The thickness of the labial cortical bone at the apical region is 1.07(0.68,1.57)mm.46%of the samples have a thickness less than 1 mm,and 18%have a thickness less than 0.5 mm.Thickness 1 mm,3 mm and 5 mm apical to the alveolar crest was 0.84,0.84 and 0.72 mm,respectively;proportions<1 mm were 68%,65%and 74%.At 3 mm and 5 mm apical to the CEJ,65%of sites exhibited thickness<1 mm.The labial bone plate was consistently thinner than the lingual bone plate at all subcrestal levels.Conclusion In individuals≥60 years,the labial cortical plate of the maxillary central incisor is generally thin,with almost half of mid-root sites<0.5 mm,indicating a high esthetic risk for immediate implant placement.The lingual bone plate was relatively abundant.Preoperative CBCT evaluation is mandatory,and patient-specific planning that considers individual anatomy and occlusal conditions is recommended.