Three-dimensional volumetric evaluation of dental pulp cavity/tooth ratio in anterior open bite malocclusion using cone beam computed tomography

Objectives: To assess and compare pulp cavity/tooth volume ratio of maxillary permanent teeth between patients exhibiting anterior open bite malocclusion and those exhibiting anterior normal overbite using cone beam computed tomography (CBCT).

Materials and methods: 3D dental images from 44 patients aged between 15 and 29 years were analyzed. The DICOM files of all dental images were imported into an image processing software for calculating pulp cavity volume and tooth volume. Differences of pulp cavity volume, tooth volume, and pulp cavity/tooth volume ratio of each tooth type from both types of occlusions were analyzed using the independent t test. The intra-class correlation coefficient was used to evaluate intra-examiner reliability.

Results: The means of pulp cavity/tooth volume ratio in anterior open bite group were significantly greater than those in anterior normal overbite group (central incisor p = 0.001; lateral incisor p = 0.00025 and canine p = 0.004). The means of root canal/root volume ratio in anterior open bite group were significantly greater than anterior normal overbite group (central incisor p = 0.00001; lateral incisor p = 0.00007; and canine p = 0.001), whereas there were no significant differences of the means of pulp chamber/crown volume was observed.

Conclusion: Anterior open bite malocclusion might lead to an increase of the pulp cavity volume and decrease of the tooth volume due to occlusal hypofunction.

Clinical relevance: Orthodontic force should be carefully determined in anterior open bite patient due to the greater root canal volume and lesser root volume.