Transverse analysis of cone-beam computed tomography (CBCT) at the canine level

OBJECTIVE: To determine the range of positions and relationships between the maxillary and mandibular canines and the related skeleton, and to evaluate using CBCT imaging whether dental and skeletal transverse discrepancies identified in the molar area also exist in the canine area. METHODS: CBCT scans of 148 patients, with and without crossbite were analyzed to assess the width of the jaws and the inclination of the canines relative to the occlusal plane. The dental and skeletal measurements were compared between the non-crossbite and the crossbite groups. RESULTS: At the canine area, we found no statistically significant differences between the non-crossbite group and the crossbite group in canine transverse angulations and maxillary and mandibular width. There is a weak statistically significant correlation between canine lingual width and both maxillary and mandibular canine axial angles that is not observed between canine palatal width and both maxillary and mandibular canine axial angles. We found a weak statistically significant correlation between maxillary canine and molar angulations as well as palatal and lingual width, but not between mandibular canine and molar angulations. CONCLUSION: We have developed a reliable method to measure transverse tooth angulation and skeletal width using CBCT at the canine level. Changes in transverse angulation and compensation observed in the molar area do not carry on at the canine area. Expansion of crossbite cases are most likely needed at the molar area, as our findings suggest that crossbites are more confined to the molar area and less expressed at the canine level