ABSTRACT
Intraoral periapical (PA) radiography is commonly used for measuring the remaining crestal bone height when implants are treatment planned in the maxillary posterior region. A major drawback of conventional radiographs is that a 3-dimensional (3D) entity is compressed and superimposed on itself into a 2-dimensional (2D) image, which is often distorted. Conversely, 3D information can be extracted from computerized tomography. The purpose of this article is to evaluate and discuss limitations of intraoral PA radiography for the measurement of posterior maxillary alveolar bone height and describe the use of information obtained by means of 3D computerized tomography to help plan implant placement. METHOD: Clinical data in this study was obtained from the Implant Database (ID) at New York University College of Dentistry (NYUCD). The data set was extracted as de-identified information from the routine treatment of patients at the Ashman Department of Periodontology and Implant Dentistry at NYUCD. The ID is certified by the Office of Quality Assurance at NYUCD. This study is in compliance with the Health Insurance Portability and Accountability Act (HIPAA) requirements. Thirty-five sites were compared with both PA and cone-beam computed tomography (CBCT) images of the posterior region, including the anatomical relationship of the maxillary crest to the sinus floor. The values recorded from the CBCT were used as the standard to which PA was subtracted from. RESULTS: Linear differences were consistently seen in which the remaining maxillary posterior crestal bone height appeared larger or smaller on the PA radiographs when compared to the measurements made of the same area on the CBCT images. CONCLUSION: CBCT imaging is a valuable adjunct in radio-anatomical and radio-diagnostic observations in the posterior maxillary region. Furthermore, in this study CBCT measurements were shown to be more accurate in assessing the remaining crestal ridge height apical to the sinus membrane when compared to PA radiographs. More research is necessary to verify these findings.
