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

Chia-Ling Hsu; Jou-En Huang; Hui-Ling Chen; Ming-Gene Tu; Jeng-Fen Liu

doi:10.1016/j.jds.2020.11.008

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

J Dent Sci. 2021 Mar;16(2):580-585. doi: 10.1016/j.jds.2020.11.008. Epub 2020 Dec 3.

Authors

Chia-Ling Hsu¹, Jou-En Huang², Hui-Ling Chen², Ming-Gene Tu^{3

4}, Jeng-Fen Liu^{1

5}

Affiliations

¹ Department of Pediatric Dentistry, Taichung Veterans General Hospital, Taichung, Taiwan.
² Department of Dentistry, Taichung Veterans General Hospital, Taichung, Taiwan.
³ Department of Endodontics, China Medical University Hospital, Taichung, Taiwan.
⁴ School of Dentistry, China Medical University, Taichung, Taiwan.
⁵ School of Dentistry, Yang Ming University, Taipei, Taiwan.

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.

Keywords: Children; Deciduous second molar; Extra third root; Permanent first molar; Three-rooted.