Verma Sneh Lata, Sharma V P, Tandon Pradeep, Singh Gyan P, Sachan Kiran
Department of Orthodontics, B.B.D. College of Dental Sciences, Lucknow, Uttar Pradesh, India.
Contemp Clin Dent. 2013 Apr;4(2):206-12. doi: 10.4103/0976-237X.114886.
The extraction of premolars as a practical form of orthodontic therapy has been accepted for many years, but there remains a controversy regarding the effect of premolar extraction to improve esthetics as well as dentoskeletal relationship. The esthetic impact of the soft-tissue profile might play a major role in deciding on premolar extraction or non-extraction treatment, particularly in borderline patients. This cephalometric study was undertaken to compare the post-treatment soft-tissue profiles of successfully managed Class II, Division 1 malocclusions treated with either all first premolar extractions or treatment with a non-extraction therapy.
The sample consisted of 100 post-pubertal female patients of Class II Division I malocclusion. Group 1, treated with four first premolar extractions, consisted of 50 female patients with a mean age of 14 years 1 month. Group 2, treated without extractions, consisted of 50 patients with a mean age of 13 years 5 months. Pre-treatment and post-treatment lateral cephalometric radiographs were evaluated. The pre-treatment to post-treatment stage comparison and the intergroup comparison of the treatment changes were conducted between extraction and non-extraction groups of Class II malocclusion samples with t-tests.
The soft-tissue facial profiles of the extraction and non-extraction samples were the same following active treatment except for a more retruded lower lip and a more pronounced lower labial sulcus in those patients subjected to extraction.
The extraction or non-extraction decision, if based on sound diagnostic criteria, seems to have no systematic detrimental effects on the facial profile.
拔除前磨牙作为正畸治疗的一种实用形式已被接受多年,但关于拔除前磨牙对改善美观及牙颌面关系的效果仍存在争议。软组织侧貌的美学影响可能在决定是否拔除前磨牙治疗或不拔牙治疗中起主要作用,尤其是在临界病例中。本头影测量研究旨在比较成功治疗的安氏II类1分类错牙合畸形患者,采用拔除所有第一前磨牙或不拔牙治疗后的软组织侧貌。
样本包括100名青春期后安氏II类1分类错牙合畸形的女性患者。第1组为拔除四颗第一前磨牙进行治疗的50名女性患者,平均年龄为14岁1个月。第2组为未拔牙治疗的50名患者,平均年龄为13岁5个月。对治疗前和治疗后的头颅侧位片进行评估。采用t检验对安氏II类错牙合畸形样本的拔牙组和非拔牙组治疗前后阶段变化及治疗变化的组间进行比较。
积极治疗后,拔牙组和非拔牙组的软组织面部侧貌相同,只是拔牙患者的下唇更后缩,下唇唇沟更明显。
如果基于合理的诊断标准,拔牙或不拔牙的决定似乎对面部侧貌没有系统性的不利影响。