Evaluation of root morphology of maxillary and mandibular second molars lost due to periodontitis

Abstract

Background and objective Little is known about the anatomical characteristics of root morphology in molars lost due to periodontal reason. The aim of this study was to study root morphology in maxillary and mandibular molars lost due to periodontitis by investigating the frequency of root fusion, classifying fusion types, and measuring radicular groove depth by micro‐computed tomography. Material and methods Ninety‐eight posterior teeth were collected from 87 Japanese patients during the study period. Of these, maxillary (N = 36) and mandibular (N = 22) second molars lost most frequently were assessed for root fusion and morphology. Results The 36 maxillary second molars included nine (25%) teeth with a single root, 14 (39%) with two roots, and 13 (36%) with three roots. Of the 23 maxillary second molars with fused (1 and 2) roots, there were 11 (48%), 2 (9%), 1 (4%), 1 (4%), 3 (13%), and 5 (22%) teeth with root types 1‐6, respectively. The 22 mandibular second molars comprised 14 (64%) teeth with a single root, 7 (32%) with two roots, and one (4%) with three roots. Of the 14 mandibular second molars with a fused (1) root, 12 (86%) had a C‐shaped root and two (14%) had a non‐C‐shaped root. Conclusion We observed a higher frequency of root fusion in the present study compared with that reported by previous studies using randomly selected second molars.

Observation of mandibular second molar roots and root canal morphology using dental cone-beam computed tomography

“…In females, the distance between the roots is generally shorter, thus more easily leading to fusion and development of a GSR. Kato et al [ 21 ] reported that teeth extracted due to periodontal disease showed a higher ratio of fused roots. In the present findings, there was no significant difference for ratio of the fused site to root thickness at the one-third of the root apex between sexs.…”

“…A supernumerary root of the mandibular molar on the lingual side was termed “radix entomolaris” [ 19 , 20 ], while that on the buccal side is known as “radix paramolaris.” Radix entomolaris is considered to be a cause for plaque accumulation like that seen with a GSR [ 21 ] and also reported to be a characteristic of Asian patients [ 20 ]. Song et al [ 8 ] found that 0.4% of GSR cases had a root on the distal lingual side and a study conducted in Indian noted that 13.3% had radix entomolaris in the mandibular first molars [ 21 ].…”

“…A supernumerary root of the mandibular molar on the lingual side was termed “radix entomolaris” [ 19 , 20 ], while that on the buccal side is known as “radix paramolaris.” Radix entomolaris is considered to be a cause for plaque accumulation like that seen with a GSR [ 21 ] and also reported to be a characteristic of Asian patients [ 20 ]. Song et al [ 8 ] found that 0.4% of GSR cases had a root on the distal lingual side and a study conducted in Indian noted that 13.3% had radix entomolaris in the mandibular first molars [ 21 ]. In the present study of mandibular second molar morphology, there was only one case (0.6%) with a supernumerary root on the lingual side of the GSR.…”

“…One report found that teeth with a GSR were more frequent in females [ 18 ], indicating a possible sex difference. Also, studies of development of a supernumerary root on the lingual side of mandibular molars have been presented [ 19 , 20 ], while root morphology has been speculated to be related to plaque accumulation [ 21 ]. As for the root canal morphology of GSR cases, examinations based on the classification of Fan et al [ 22 ] have been conducted.…”

Assessment of Mandibular Molar Root Morphology Using Cone‑Beam Computed Tomography in Periodontitis Patients From Eastern Province: A Cross-Sectional Study

“…However, they did not investigate the morphological aspects of fused roots in detail. Thus, a detailed examination of the morphological abnormalities that could be present in roots lost due to periodontitis is essential for a better understanding of the factors that would affect disease progression [ 19 ].…”