Evaluation of apical foramen position and distance from the anatomical apex of roots in anterior maxillary teeth by cone-beam computed tomography (CBCT) in a selected Iranian population

Enough knowledge of the internal anatomy and apical foramen of a tooth has always been a fundamental prerequisite for root canal therapy. The current study aimed to determine the position and distance of apical foramen to anatomical apex in maxillary anterior teeth in cone-beam computed tomography (CBCT) in the Iranian population.

In this retrospective cross-sectional study, CBCT scans of 250 patients referred to a dental clinic in the city of Babol, Mazandaran province, are investigated. The inclusion criteria were being aged 18 to 70 years, and having maxillary teeth from right canine to left canine. The exclusion criteria were history of trauma in the anterior of maxilla, the openness of the apex, not finding the apex, endodontically treated tooth, surgery in the apical area, and dental anomalies. Maxillary anterior teeth  were examined for apical foramen position and radiographic foramen-apex distance by CBCT in coronal and sagittal planes. Age, gender, and quadrant of teeth were recorded, and their association with radiographic foramen-apex distance was investigated.  Finally, data were analyzed using ANOVA and Independent T-test with P≤ 0.05 was considered significant.

The mean foramen-apex distance in central incisor teeth was 0.53±0.28 mm, in lateral incisor teeth was 0.56±0.31 mm, and in canine teeth was 0.76±0.39 mm. The frequency of apical foramen position in central and lateral teeth was 34.1% and 22.6% centrally, and in canine teeth was 20% distally, respectively. Age and quadrant had no effect on foramen-apex distance. The radiographic foramen-apex distance was higher in men than women, which was statistically significant (P-value=0.003).

Based on the findings, it seems that in the treatment of the root of the anterior teeth of the maxilla, if the working length is considered to be 1 mm shorter than the radiographic apex, it will be better.