Crown morphology and additional canals in mandibular incisors using cone-beam computed tomography: A geometric...

Area of Science:

• Dentistry
• Endodontics
• Dental Anatomy

Background:

• Mandibular incisors typically possess a single root and canal, but anatomical variations including additional canals can occur.
• Failure to detect accessory canals during endodontic treatment is a common cause of treatment failure.

Purpose of the Study:

• To investigate the relationship between mandibular incisor crown morphology, dimensions, and the presence of additional root canals.
• To determine if tooth shape and dimensions can serve as predictors for accessory canals in mandibular incisors.

Main Methods:

• Cone-beam computed tomography (CBCT) and two-dimensional geometric morphometry were employed to analyze tooth shape and dimensions.
• Coronal morphology and landmark coordinates were documented and analyzed using specialized software (TPSutil, TPSdig2, MorphoJ).
• Statistical analyses included Chi-square tests, Procrustes ANOVA, and discriminant function analysis (DFA).

Main Results:

• Of 108 mandibular incisors, 47.2% exhibited additional canals (primarily Type II).
• Discriminant function analysis achieved 63.9% accuracy in classifying teeth with single versus additional canals.
• Teeth with additional canals showed increased buccal and lingual crest widths and reduced incisal height compared to single-canal teeth.

Conclusions:

• While certain morphological variations like increased crest width and reduced incisal height are associated with additional canals, these differences were not statistically significant for buccolingual width.
• Overall crown dimensions and shape do not provide a reliable prediction for the presence of extra canals in mandibular incisors.
• Accurate identification of canal anatomy remains critical for successful endodontic outcomes.