Main Instructor Yi-Hua Liu1
Department / Institution Department of Orthodontics, Chi-Mei Medical Center, Tainan City, Taiwan
Classification Case report
Impaction of mandibular second molar is a rare and it is often not so easy to upright and assist its eruption for orthodontists.
This case reported a 16-year old female who presented the straight lateral profile, high mandibular plane angle, bilateral impacted lower second molars and bilateral upper second molars buccal crossbite. The orthodontic treatment was completed using lingual holding arch with extending arm to draw and upright the impacted lower second molars into occlusion, which is a very simple and useful device. The buccal crossbite of upper second molars was also corrected with similar design by transpalatal arch with extending arm and elastic chain. Treatment outcome showed impacted and crossbite second molars were corrected successfully. In the same time, satisfying occlusion, bilateral canine and molar class I relationship and well periodontal condition were also achieved.
「Discussion & Summary」
Impacted lower second molar may cause dental caries, root resorption, pericoronal inflammation and periodontal breakdown of the first molar. Early detection and proper treatment is imperative to avoid these risks and to reach best long-term prognosis. In this case, a modification of lingual holding arch with extending arm is described as an easy and efficient method for molar uprighting. By periodic changing the elastic chain, the impacted second molar had been uprighted efficiently and achieved favorable periodontal support and well occlusal function.
Orthodontic Treatment of Bilateral Impacted Mandibular Second Molars with Lingual Holding Arch with Extending Arm.