Key factors for successful eruption of the mandibular third molar after extraction of the mandibular second molar.

IF 2.6 3区医学 Q1 DENTISTRY, ORAL SURGERY & MEDICINE

Korean Journal of Orthodontics Pub Date : 2025-03-25 Epub Date: 2025-01-09 DOI:10.4041/kjod24.210

Jung Jin Park, Yoonjeong Noh, Yoon Jeong Choi, Jae Hyun Park, Ji Hyun Lee, Chooryung Judi Chung, Kyung-Ho Kim

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引用次数: 0

Abstract

Objective: Extraction of the mandibular second molar (L7) and substitution by the mandibular third molar (L8) is an effective treatment option. This study aimed to evaluate spontaneously erupted L8 occlusion after L7 extraction, and identify the influencing factors.

Methods: This study assessed 46 L8 from 28 patients using dental study models, panoramic radiographs, and lateral cephalograms obtained during L7 extraction (T1) and completion of L8 eruption (T2). At T2, samples were categorized as acceptable (A-group) or unacceptable (U-group) based on the American Board of Orthodontics index. L8 angulation and position, retromolar space, distance between the Xi point and mandibular first molar (L6), and Nolla stage were compared between the groups to identify the predictive factors for successful eruption.

Results: At T2, 58.7% of L8 exhibited acceptable occlusion. Age at T1 was significantly higher in the U-group than that in the A-group. Angles ∟6-MnP and ∟8-MnP differed significantly between the groups at T2. Xi-L6 distance was considerably longer in the A-group than that in the U-group at T1 and T2. Younger age at extraction and Xi-L6 distance at T1 affected the acceptable occlusion.

Conclusions: Younger age at L7 extraction and adequate eruption space (Xi-L6 distance) appear to be the key factors for achieving acceptable L8 occlusion.

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来源期刊

Korean Journal of Orthodontics DENTISTRY, ORAL SURGERY & MEDICINE-

CiteScore

3.50

自引率

10.50%

发文量

审稿时长

>12 weeks

期刊介绍： The Korean Journal of Orthodontics (KJO) is an international, open access, peer reviewed journal published in January, March, May, July, September, and November each year. It was first launched in 1970 and, as the official scientific publication of Korean Association of Orthodontists, KJO aims to publish high quality clinical and scientific original research papers in all areas related to orthodontics and dentofacial orthopedics. Specifically, its interest focuses on evidence-based investigations of contemporary diagnostic procedures and treatment techniques, expanding to significant clinical reports of diverse treatment approaches. The scope of KJO covers all areas of orthodontics and dentofacial orthopedics including successful diagnostic procedures and treatment planning, growth and development of the face and its clinical implications, appliance designs, biomechanics, TMJ disorders and adult treatment. Specifically, its latest interest focuses on skeletal anchorage devices, orthodontic appliance and biomaterials, 3 dimensional imaging techniques utilized for dentofacial diagnosis and treatment planning, and orthognathic surgery to correct skeletal disharmony in association of orthodontic treatment.