Restor Dent Endod.  2022 May;47(2):e19. 10.5395/rde.2022.47.e19.

Morphotypes of the apical constriction of maxillary molars: a micro-computed tomographic evaluation

• Chang JWW
• Manigandan K
• Samaranayake L
• NandhaKumar C
• AdhityaVasun P
• Diji J
• PradeepKumar AR

• KMID: 2548123
• DOI: http://doi.org/10.5395/rde.2022.47.e19

Abstract

Objectives
The aim of this study was to evaluate and compare the apical constriction (AC) and apical canal morphology of maxillary first and second molars, using micro-computed tomography (micro-CT).
Materials and Methods
The anatomical features of 313 root canals from 41 maxillary first molars and 57 maxillary second molars of patients with known age and sex were evaluated using micro-CT, with a resolution of 26.7 µm. The factors evaluated were the presence or absence of AC, the morphotypes, bucco-lingual dimension, mesio-distal dimension, and the profile (shape) of AC and the apical root canal. The apical root canal dimensions, location of the apical foramen (AF), AC to AF distance, and presence of accessory canals in the apical 5 mm were also assessed. Descriptive and analytical statistics were used for data evaluation.
Results
AC was present in all 313 root canals. Patients’ age and sex did not significantly impact either AC or the apical canal dimensions. The most common AC morphotype detected was the traditional (single) constriction (52%), followed by the parallel (29%) morphotype. The mean AC dimensions in maxillary first molars were not significantly different from those in maxillary second molars. Sixty percent of AF were located within 0.5 mm from the anatomic apex.
Conclusions
The most common morphotype of AC detected was the traditional constriction. Neither patients’ age nor sex had a significant impact on the dimensions of the AC or the apical root canal. The majority of AF (60%) were located within 0.5 mm from the anatomic apex.

Keyword

Apical constriction; Canal dimension; Maxillary molars; Micro-computed tomography

Figure

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  Figure 1 Apical constriction morphotypes: (A) traditional constriction, (B) parallel constriction, (C) delta constriction, and (D) tapering constriction.

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  Figure 2 Complex multiple apical ramifications in a delta constriction.

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  Figure 3 Apical canal dimensions: the mesio-buccal and disto-buccal canals are wider in the bucco-palatal dimension, and the palatal canal is wider in the mesio-distal dimension.

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  Figure 4 Lateral view of the anatomic apex showing apical foramen deviation.

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  Figure 5 Presence of accessory canals in a first mesio-buccal canal.

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