Kokich V O, Kiyak H A, Shapiro P A
Department of Oral and Maxillofacial Surgery, School of Dentistry, University of Washington, Seattle, USA.
J Esthet Dent. 1999;11(6):311-24. doi: 10.1111/j.1708-8240.1999.tb00414.x.
This study was designed to determine the perceptions of lay people and dental professionals with respect to minor variations in anterior tooth size and alignment and their relation to the surrounding soft tissues.
Smiling photographs were intentionally altered with one of eight common anterior esthetic discrepancies in varying degrees of deviation, including variations in crown length, crown width, incisor crown angulation, midline, open gingival embrasure, gingival margin, incisal plane, and gingiva-to-lip distance. Forty images were randomized in a questionnaire and rated according to attractiveness by three groups: orthodontists, general dentists, and lay people; 300 questionnaires were distributed.
The response rate was 88.2% for orthodontists, 51.8% for general dentists, and 60.6% for lay people. The results demonstrated threshold levels of noticeable difference between the varying levels of discrepancy. A maxillary midline deviation of 4 mm was necessary before orthodontists rated it significantly less esthetic than the others. However, general dentists and lay people were unable to detect even a 4-mm midline deviation. All three groups were able to distinguish a 2-mm discrepancy in incisor crown angulation. An incisal plane cant of 1 mm as well as a 3-mm narrowing in maxillary lateral incisor crown width were required by orthodontists and general dentists to be rated significantly less esthetic. Lay people were unable to detect an incisal plane asymmetry until it was 3 mm, or a lateral incisor narrowing until it reached 4 mm. Threshold levels for open gingival embrasure and gingiva-to-lip distance were both at 2 mm for the orthodontic group. Open gingival embrasure became detectable by the general dentists and lay people at 3 mm, whereas gingiva-to-lip distance was classified by these groups as noticeably unattractive at 4 mm.
The results of this study show that orthodontists, general dentists, and lay people detect specific dental esthetic discrepancies at varying levels of deviation, which may aid the dental professional in making specific treatment recommendations.
本研究旨在确定外行人及牙科专业人员对前牙大小和排列的微小差异及其与周围软组织关系的看法。
微笑照片被故意改变，呈现出八种常见的前牙美学差异之一，且偏差程度各异，包括冠长、冠宽、切牙冠角、中线、龈外展隙、牙龈边缘、切平面以及龈唇距离的变化。40张图像随机编入问卷，由三组人员根据吸引力进行评分：正畸医生、普通牙医和外行人；共发放300份问卷。
正畸医生的回复率为88.2%，普通牙医为51.8%，外行人 为60.6%。结果表明，不同差异水平之间存在明显差异的阈值。正畸医生认为上颌中线偏差达4毫米时，其美观程度明显低于其他情况。然而，普通牙医和外行人甚至无法察觉4毫米的中线偏差。所有三组人员都能辨别出切牙冠角2毫米的差异。正畸医生和普通牙医认为，切平面倾斜1毫米以及上颌侧切牙冠宽变窄3毫米时，美观程度明显降低。外行人直到切平面不对称达到3毫米或侧切牙变窄达到4毫米时才能察觉。正畸组龈外展隙和龈唇距离的阈值均为2毫米。普通牙医和外行人在3毫米时能察觉到龈外展隙，而这些组认为龈唇距离在4毫米时明显不美观。
本研究结果表明，正畸医生、普通牙医和外行人在不同偏差水平下能检测到特定的牙齿美学差异，这可能有助于牙科专业人员做出具体的治疗建议。
