PATTERN OF THE FORMATION AND ERUPTION OF FIRST PERMANENT MOLARS

Jeong, Hae-Kyoung; Yang, Yeon-Mi; Kim, Jae-Gon; Baik, Byeong-Ju; Soh, Yu-Ryeo

Journal of the Korean Academy of Pediatric Dentistry 2010;37(3):317-327.
Published online August 31, 2010.

PATTERN OF THE FORMATION AND ERUPTION OF FIRST PERMANENT MOLARS

Hae-Kyoung Jeong, Yeon-Mi Yang, Jae-Gon Kim, Byeong-Ju Baik, Yu-Ryeo Soh

Department of Pediatric Dentistry and Institute of Oral Bioscience, School of Dentistry, Chonbuk National University

제1대구치의 석회화와 맹출 양상

정해경, 양연미, 김재곤, 백병주, 소유려

전북대학교 치의학전문대학원 소아치과학교실 및 구강생체과학연구소

Correspondence: Yeon-Mi Yang, Tel: 063-250-2128, Email: pedodent@chonbuk.ac.kr

Received: 19 February 2010 • Accepted: 16 June 2010

Abstract

Among the permanent teeth, the first permanent molars play the greatest role in occlusion and function. So, early diagnosis for congenital missing, abnormal eruption and abnormal formation is very important to the first permanent molars in the course of arch development. The aim of this study is to analyse the differences between right and left first permanent molar's formation and eruption and between upper and lower one. A total of 545 children were selected am ong children who had visited our clinic, investigate eruption and calcification stage of permanent first molar, based on Gleiser and Hunt criteria for this study. 1. Gingival emergence of mandibular first molar is faster than maxillary first molar by 0.75~0.8 years, gingival emergence of maxillary first molar in girls faster than boys by 0.45 years, and that of mandibular first molar in girls faster than boys by 0.5 years. 2. There is the significant difference between right and left first molar on the eruption score and the calcification stage ; 5 year old children show the significant difference on the eruption score. 7 year old children show the significant difference on both the eruption score and calcification stage. 3. It shows the most active eruption movement of crown on the maxilla while the root is rapidly widening its furcation and completing root formation to 2/3, on the other hand, the most active crown emerging on mandible is shown when the root formation completed to 1/4 to 1/2.

Key Words: First molar, Eruption, Calcification, Gleiser and Hunt