The purpose of this study was to apply cone-beam computed tomography （CBCT） to observe contour changes in human alveolar bone after tooth extraction of the maxillary central incisor and to provide original mor- phol...The purpose of this study was to apply cone-beam computed tomography （CBCT） to observe contour changes in human alveolar bone after tooth extraction of the maxillary central incisor and to provide original mor- phological evidence for aesthetic implant treatment in the maxillary anterior area. Forty patients were recruited into the study. Each patient had two CBCT scans （CBCT I and CBCT II）, one taken before and one taken three months after tooth extraction of maxillary central incisor （test tooth T）. A fixed anatomic reference point was used to orient the starting axial slice of the two scans. On three CBCT I axial slices, which represented the deep, middle, and shallow layers of the socket, labial and palatal alveolar bone widths of T were measured. The number of sagittal slices from the start point to the pulp centre of T was recorded. On three CBCT II axial slices, the pulp centres of extracted T were oriented according to the number of moved sagittal slices recorded in CBCT I. Labial and palatal alveolar bone widths at the oriented sites were measured. On the CBCT I axial slice which represented the middle layer of the socket, sagittal slices were reconstructed. Relevant distances of T on the sagittal slice were measured, as were the alveolar bone width and tooth length of the opposite central incisor. On the CBCT II axial slice, which represented the middle layer of the socket, relevant distances recorded in CBCT I were transferred on the sagittal slice. The height reduction of alveolar bone on labial and palatal sides was measured, as were the alveolar bone width and tooth length of the opposite central incisor at the oriented site. Intraobserver reliability assessed by intraclass correlation coefficients （ICCs） was high. Paired sample t-tests were performed. The alveolar bone width and tooth length of the opposite central incisor showed no statistical differences （P〈0.05）. The labial alveolar bone widths of T at the deep, middle, and shallow layers all showed statistical differences. However, no palatal alveolar bone widths showed any statistical differences. The width reduction of alveolar bone was 1.2, 1.6, and 2.7 mm at the deep, middle, and shallow layers, respectively. The height reduction of alveolar bone on labial and palatal sides of T both showed statistical differences, which was 1.9 and 1.1 mm, respectively.展开更多
The purpose of this study was to demonstrate the feasibility of applying cone-beam computed tomography（CBCT） to observe dimensional changes in human alveolar bone continuously after tooth extraction.Sixty patients w...The purpose of this study was to demonstrate the feasibility of applying cone-beam computed tomography（CBCT） to observe dimensional changes in human alveolar bone continuously after tooth extraction.Sixty patients were selected from a CBCT database.Each patient had two CBCT scans（CBCT I and CBCT II）,one taken before and one taken after implant surgery.A fixed anatomic reference point was used to orient the horizontal slice of the two scans.The alveolar ridge width was measured on the horizontal slice.In each series of CBCT I sagittal slices,the number of slices from the start point to the pulp center of the test tooth was recorded.The tooth length was measured on the sagittal slice.In each series of CBCT II slices,tooth length was measured on a sagittal slice selected based on the number of slices from the start point to the pulp center recorded in CBCT I.Intraobserver reliability,assessed by the intraclass correlation coefficient（ICC）,was high.Paired sample t-tests of repeated measurements of both tooth length and alveolar bone width showed no statistically significant differences（P0.05）.This study has proved that projection differences among CBCT scans taken at different time points from one patient can be neglected without affecting the accuracy of millimeter scale measurements.CBCT is a reliable imaging tool for continuously observing dimensional changes in human alveolar bone.展开更多
文摘The purpose of this study was to apply cone-beam computed tomography （CBCT） to observe contour changes in human alveolar bone after tooth extraction of the maxillary central incisor and to provide original mor- phological evidence for aesthetic implant treatment in the maxillary anterior area. Forty patients were recruited into the study. Each patient had two CBCT scans （CBCT I and CBCT II）, one taken before and one taken three months after tooth extraction of maxillary central incisor （test tooth T）. A fixed anatomic reference point was used to orient the starting axial slice of the two scans. On three CBCT I axial slices, which represented the deep, middle, and shallow layers of the socket, labial and palatal alveolar bone widths of T were measured. The number of sagittal slices from the start point to the pulp centre of T was recorded. On three CBCT II axial slices, the pulp centres of extracted T were oriented according to the number of moved sagittal slices recorded in CBCT I. Labial and palatal alveolar bone widths at the oriented sites were measured. On the CBCT I axial slice which represented the middle layer of the socket, sagittal slices were reconstructed. Relevant distances of T on the sagittal slice were measured, as were the alveolar bone width and tooth length of the opposite central incisor. On the CBCT II axial slice, which represented the middle layer of the socket, relevant distances recorded in CBCT I were transferred on the sagittal slice. The height reduction of alveolar bone on labial and palatal sides was measured, as were the alveolar bone width and tooth length of the opposite central incisor at the oriented site. Intraobserver reliability assessed by intraclass correlation coefficients （ICCs） was high. Paired sample t-tests were performed. The alveolar bone width and tooth length of the opposite central incisor showed no statistical differences （P〈0.05）. The labial alveolar bone widths of T at the deep, middle, and shallow layers all showed statistical differences. However, no palatal alveolar bone widths showed any statistical differences. The width reduction of alveolar bone was 1.2, 1.6, and 2.7 mm at the deep, middle, and shallow layers, respectively. The height reduction of alveolar bone on labial and palatal sides of T both showed statistical differences, which was 1.9 and 1.1 mm, respectively.
基金supported by the National Natural Science Foundation of China(No.81371115)
文摘The purpose of this study was to demonstrate the feasibility of applying cone-beam computed tomography（CBCT） to observe dimensional changes in human alveolar bone continuously after tooth extraction.Sixty patients were selected from a CBCT database.Each patient had two CBCT scans（CBCT I and CBCT II）,one taken before and one taken after implant surgery.A fixed anatomic reference point was used to orient the horizontal slice of the two scans.The alveolar ridge width was measured on the horizontal slice.In each series of CBCT I sagittal slices,the number of slices from the start point to the pulp center of the test tooth was recorded.The tooth length was measured on the sagittal slice.In each series of CBCT II slices,tooth length was measured on a sagittal slice selected based on the number of slices from the start point to the pulp center recorded in CBCT I.Intraobserver reliability,assessed by the intraclass correlation coefficient（ICC）,was high.Paired sample t-tests of repeated measurements of both tooth length and alveolar bone width showed no statistically significant differences（P0.05）.This study has proved that projection differences among CBCT scans taken at different time points from one patient can be neglected without affecting the accuracy of millimeter scale measurements.CBCT is a reliable imaging tool for continuously observing dimensional changes in human alveolar bone.
