Linear tomography's clinical accuracy and validity for presurgical dental implant analysis

Accurate assessment of alveolar ridge morphology and inferior alveolar canal location is critical in the presurgical planning phase for dental implant therapy. This study examined the accuracy and validity of linear tomography in the presurgical assessment of potential mandibular implant sites. Seven subjects (six oral and maxillofacial surgeons and one oral radiologist) traced the mandibular cortical bone and inferior alveolar canal on linear tomographic images taken from five mandibles on five separate occasions over 5 weeks. Tracings and the sectioned mandibles were scanned into a computer and assessed for eight measurement criteria. Statistically significant findings were present for intraobserver variability, interobserver variability, and differences between the perceived and actual anatomic structures within the assessed plane of section. These findings demonstrate that the inherent dimensional instability of linear tomography severely limits its diagnostic and clinical role in preoperative implant site assessment.