(PO86) Projection of the Apical Straight Line in Relation to the Facial Plate of Maxillary Anterior Teeth - A CBCT Analysis

Abstract: Understanding root canal anatomy from a retrograde perspective is crucial for favorable apical surgery outcomes. Traditional pre-surgical assessments focus on the distance between the root apex and the facial plate, yet the straight-line access to the canal is equally important for optimizing the depth of retroseal placement. This cone beam computed tomography study examines the angulation of the apical canal's straight line relative to the facial, enhancing the pre-surgical evaluation of anterior teeth. The study analyzed 100 limited field-of-view cone beam computed tomography scans of maxillary anterior teeth. The scans were aligned in three planes along the tooth's long axis. A simulated post-resection apex was established by deducting three millimeters from the radiographic apex on the sagittal plane. Two best-fit lines were identified: one along the facial plate and another along the apical half of the remaining canal space, projected apically until they intersected. Data collected included the intersection angle, distance to the post-resection apex, tooth type, sex, and age. Statistical analysis through linear regression models sought to uncover relationships between these variables. Of the 92 scans analyzed, a significant inverse correlation was found between the angle and distance. In canines, a higher angle was associated with males compared to females, with age showing no influence on the outcomes.The findings suggest that teeth with a larger intersection angle may permit a more conservative osteotomy, easier retroseal placement, and potentially improved treatment outcomes.