The relationship of the occurrence between three-rooted deciduous mandibular second molars and three-rooted permanent mandibular first molars in children

Abstract

Background/purpose This study aimed to determine the correlation between the occurrence of three-rooted deciduous mandibular second molars and three-rooted permanent mandibular first molars in children. Materials and methods Orthopantograms (n = 977) obtained from August 2008 to December 2010 were retrospectively screened and examined. Among the 977 orthopantograms, those of 591 participants (314 boys and 277 girls; mean age, 8.7 years) with bilateral deciduous mandibular second molars and permanent mandibular first molars were studied. The gender predilection and prevalence of three-rooted mandibular molars were assessed, and the pattern of concurrence was investigated. Results The prevalence of three roots were 28.4% and 27.6% in the deciduous mandibular second molars and permanent mandibular first molars, respectively. Bilateral occurrence of three-rooted mandibular molars was almost 60% for both deciduous and permanent molars. There was a significantly greater prevalence of three-rooted mandibular molars on the right side of the mandible than that on the left side. Conclusion Deciduous and permanent molars show a similar prevalence of three roots. The presence of three-rooted deciduous mandibular second molar can strongly predict the possibility of three roots in permanent mandibular first molar.

Investigation of three-rooted deciduous mandibular second molars in a Chinese population using cone-beam computed tomography

“…This in vivo study investigated the anatomic features of three-rooted DMSMs by using CBCT. Although the sample size is smaller than several previous studies based on panoramic [ 13 ] or periapical radiographs [ 18 ], CBCT allows for more accurate detection of the DL root and non-invasive 3D odontometric analysis, especially can provide valuable anatomic information from the proximal view.…”

Prevalence of Three-Rooted Deciduous Mandibular Molars in the Children of Northwestern Iran

“…Multiple variables, including sample size, research design, analysis method, and studied populations, can influence the incidence of three-rooted mandibular molars. Two main approaches are used to assess the incidence of extra roots in previous research studies: (1) Radiography, which is a noninvasive method, and (2) Examination of extracted teeth which provides a more detailed knowledge of the root morphology but is considered as invasive [ 19 ].…”

“…In our study, we used periapical radiographs, instead of extracted teeth, for analyzing larger number of subjects. Extraction and CT, on the other hand, are more precise approaches for assessing the morphological root anomalies [ 19 , 28 ].…”

“…Some research has been recently conducted using CT, CBCT, and micro-CT to study the prevalence of extra roots in mandibular deciduous and permanent molars. Spiral CT can show accurate three-dimensional images, which can be helpful for endodontic applications and morphologic studies, while traditional radiographs only provide a two-dimensional view of the teeth [ 19 , 23 , 28 – 30 ].…”

“…Despite numerous studies regarding this issue in permanent teeth, only a few studies have focused on primary molars and the majority of them are case studies [ 19 ].…”