Accuracy and reliability of tooth length measurements on conventional and CBCT images: An in vitro comparative study.

CONTEXT: The purpose of this study was to evaluate the accuracy and reliability of tooth length measurements using conventional and cone-beam computed tomography (CBCT) imaging techniques.

AIM: The aim of this study was to assess the accuracy and reliability of various tooth length measurements made on CBCT scans and conventional imaging techniques [intraoral periapical radiograph (IOPA) and orthopantomogram (OPG)].

SETTINGS AND DESIGN: This is an in-vitro comparative study.

SUBJECTS AND METHODS: In total, 50 extracted single-rooted premolar teeth were mounted on the dry human mandible. For each extracted tooth, measurements for tooth length, crown length, and root lengths were taken with a Vernier caliper and using three imaging modalities: CBCT, OPG, and IOPA radiographs. The measurements were compared with the gold standard (Vernier caliper).

STATISTICAL ANALYSIS USED: One-way analysis of variance was used to compare mean values between the groups that are Vernier caliper, CBCT, IOPA, and OPG. The multiple comparisons of means of tooth length, root length, and crown length were done by Bonferroni test.

RESULTS: A significant difference in the tooth length measurements was seen between the measurements taken by CBCT and IOPA and between IOPA and OPG. But, no significant difference was seen between any other groups. The highly significant difference was seen between the root length measurements taken by IOPA and OPG and by CBCT and OPG. However, no significant difference was seen between any other groups. No significant difference was seen in between the crown length measurements taken by Vernier caliper and CBCT and between IOPA and OPG. However, a significant difference was seen between all the groups.

CONCLUSIONS: Among the radiographic techniques, CBCT was found to be the most accurate in measuring the tooth, root, and crown lengths.