Department of Orthodontics, Manipal College of Dental Sciences, Manipal Academy of Higher Education, Manipal, Karnataka, India.
Department of Orthodontics, Manipal College of Dental Sciences, Manipal Academy of Higher Education, Manipal, Karnataka, India.
Am J Orthod Dentofacial Orthop. 2020 Nov;158(5):684-693. doi: 10.1016/j.ajodo.2019.09.024. Epub 2020 Sep 30.
This retrospective pilot study assessed the pre- and posttreatment lip profile changes among adult patients with Class II Division 1 malocclusion of varied growth patterns and compared these changes with patients with a skeletal Class I relationship, to identify the dental, skeletal, and soft tissue cephalometric variables that altered the posttreatment lip profile.
A total of 33 digital cephalograms were divided into 4 study groups based on the mandibular plane (Mp-SN) angle: group 1 (control, skeletal Class I; mean angle = 21.5°) (n = 8), group 2 (Class II Division 1 malocclusion; low angle = <26°) (n = 8), group 3 (Class II Division 1 malocclusion; intermediate angle = 26°-38°) (n = 9), and group 4 (Class II Division 1 malocclusion; high angle = >38°) (n = 8).
We observed a significant decrease in SNA, ANB, maxillary incisor to NA (degrees and millimeters), and soft tissue parameters, especially lip strain and lower lip to E line and upper lip to E line. Posttreatment intergroup comparison showed a significant increase of Mp-SN, and this increase was greater in group 3, followed by group 4 as compared with group 1. In addition, statistically significant differences in SNA, ANB, mandibular incisor to NB (degrees) and IMPA, and H angle in groups 2-4 were observed.
Patients with Class II Division 1 malocclusion showed a significant decrease in SNA, ANB, maxillary incisor to NA, and all soft tissue parameters in posttreatment compared with group 1. Thus, the soft tissue changes resulted in a similar profile to patients in group 1, who are considered to have an aesthetically pleasing posttreatment profile.
本回顾性试点研究评估了不同生长模式的成人安氏 II 类 1 分类错牙合患者治疗前后的唇侧轮廓变化，并将这些变化与骨骼 I 类关系的患者进行比较，以确定改变治疗后唇侧轮廓的牙齿、骨骼和软组织头影测量学变量。
根据下颌平面（Mp-SN）角将 33 个数字头颅侧位片分为 4 个研究组：第 1 组（对照组，骨骼 I 类；平均角度=21.5°）（n=8），第 2 组（安氏 II 类 1 分类错牙合；低角<26°）（n=8），第 3 组（安氏 II 类 1 分类错牙合；中角 26°-38°）（n=9）和第 4 组（安氏 II 类 1 分类错牙合；高角>38°）（n=8）。
我们观察到 SNA、ANB、上颌切牙至 NA（度和毫米）和软组织参数显著下降，特别是唇紧张度和下唇至 E 线和上唇至 E 线。治疗后组间比较显示 Mp-SN 显著增加，且第 3 组增加最大，其次是第 4 组，与第 1 组相比。此外，在第 2-4 组中还观察到 SNA、ANB、下颌切牙至 NB（度）和 IMPA、H 角的统计学显著差异。
与第 1 组相比，安氏 II 类 1 分类错牙合患者治疗后 SNA、ANB、上颌切牙至 NA 和所有软组织参数均显著下降。因此，软组织变化导致与被认为具有美观治疗后轮廓的第 1 组患者相似的轮廓。
