Microcomputed tomography analysis of root canal morfology of hypomineralized permanent molars compared with healthy teeth: unveiling hidden anatomical variations

TL;DR

This study uses microcomputed tomography to compare the root canal structure of teeth with a developmental enamel defect to healthy teeth, revealing differences in minor apical foramina and cervical width.

Contribution

The study provides new insights into root canal morphology variations in hypomineralized molars using µCT, which is critical for endodontic treatment planning.

Findings

Hypomineralized teeth had significantly more minor apical foramina in the middle third of the root compared to healthy teeth.

The cervical width was significantly greater in hypomineralized molars than in healthy molars.

No significant differences were found in cervical thickness, canal area, or isthmus distribution between the two groups.

Abstract

Molar–incisor hypomineralization (MIH) is a prevalent developmental enamel defect that frequently affects permanent molars and is associated with increased dentin permeability, hypersensitivity, and a higher risk of pulpal inflammation. These clinical features may necessitate endodontic treatment at an early age; however, information regarding potential variations in root canal morphology in MIH-affected molars remains limited. This study aimed to investigate the root canal morphology of hypomineralized permanent molars and compare it with that of healthy molars via microcomputed tomography (µCT).

A total of sixty extracted permanent molars were included in this study, comprising thirty hypomineralized teeth and thirty healthy control teeth. All samples were scanned using a SkyScan 1172 µCT system. Root canal configurations were classified according to the Sert and Bayırlı classification system, and isthmus types were assessed according to the system described by Hsu and Kim. The numbers of major and minor apical foramina were recorded. Morphometric analyses included measurements of canal area, cervical width, and cervical thickness. All the data were statistically analyzed via independent t tests, with the level of significance set at p < 0.05.

The most common root canal configuration in both groups was Type I, defined as the presence of two canals without noticeable communication. Hypomineralized teeth exhibited a significantly greater number of minor apical foramina in the middle third of the root (p = 0.016) as well as a greater total number of minor apical foramina compared with healthy teeth (p = 0.047). The cervical width was significantly greater in the hypomineralized molars (p = 0.02), whereas no significant differences were observed in the cervical thickness, canal area, or isthmus distribution between the two groups.

µCT analysis demonstrated distinct morphological differences between hypomineralized and healthy permanent molars, particularly regarding the number of minor apical foramina and cervical width. These findings underscore the need to consider potential root canal variations during endodontic assessment and treatment planning in MIH-affected molars.

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