Distances of root apices to adjacent anatomical structures in the anterior maxilla: an analysis using cone beam computed tomography.

Objectives: The aim was to assess the anatomical relationship of anterior maxillary teeth to the nasal floor in patients referred for apical surgery.
Materials and Methods: Cone beam computed tomographic images (CBCT) of 83 patients were analysed retrospectively to quantify the distances between the root apices of maxillary anterior teeth (canine to canine) to the nasal floor or maxillary sinus (whichever was closer). Secondary outcome variables were the distances of the periapical lesion to the nasal floor, distances of the apices to the labial and palatal bone plates as well as to the neighbouring teeth.
Results: A total of 93 teeth (39 central, 35 lateral incisors and 19 canines) were analysed. The mean shortest distances of the apices to the nasal floor (or maxillary sinus) were 8.54 mm for central incisors, 9.49 mm for lateral incisors and 5.39 mm for the canines. The canines exhibited a significantly shorter distance to the nasal floor/maxillary sinus. In the presence of an osteolysis, the distance to the nasal floor was significantly shorter compared to the teeth without lesions. The lateral and central incisors showed significant proximity to each other at the level of the future surgical resection (3 mm from the apex).
Conclusions: A close proximity between apices and adjacent anatomical structures such as nasal floor, maxillary sinus or adjacent roots could be shown in some cases.
Clinical Relevance: CBCT could be a valuable adjunctive imaging tool prior to apical surgery in the anterior maxilla to assess the risk for and decrease the incidence of damage to neighbouring anatomical structures such as the nasal floor, maxillary sinus or adjacent roots.