title: Esthetic evaluation of incisor inclination in smiling profiles with respect to mandibular position.
abstract: BACKGROUND
  The smile is a key facial expression, and a careful assessment of the facial profile in smiling is an essential part of a complete orthodontic diagnosis. The aim of this study was to determine the preferred maxillary incisor inclination in the smile profile with regard to different mandibular positions.
  
  
  METHODS
  A smiling profile photograph of a man with normal facial profile features was altered digitally to obtain 3 different mandibular sagittal positions in 4-mm decrements or increments from -4 to +4 mm. In each mandibular position, the inclination of the maxillary incisors was changed from -10° to +10° in 5° increments. A total of 234 raters (72 senior dental students, 24 orthodontists, 21 maxillofacial surgeons, 25 prosthodontists, and 92 laypeople) were asked to score each photograph using a Likert-type rating scale. Mann-Whitney, Kruskal-Wallis, and intraclass correlation coefficient tests were used to analyze the data.
  
  
  RESULTS
  In retruded and protruded mandibles, normal incisor inclination and the most retroclined incisors were selected as the most and the least attractive images, respectively, by almost all groups. With an orthognathic mandible, the image with the most retroclined incisors was selected as the least attractive, but the raters were not unanimous regarding the most attractive image. The intraclass correlation coefficient was 0.82 (high level of agreement). Also, the sex of the raters had no effect on the rating of the photographs.
  
  
  CONCLUSIONS
  It is crucial to establish a normal incisor inclination, especially in patients with a mandibular deficiency or excess. An excessive maxillary incisor lingual inclination should be avoided regardless of the mandibular position.
authors: Assistant professor, Orthodontic Research Center, Department of Orthodontics, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran. Electronic address: zarifhooman@gmail.com.
authors: Hooman
authors: H
authors: Zarif Najafi
authors: Private practice, Tehran, Iran.
authors: Morteza
authors: M
authors: Oshagh
authors: Student research committee, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran.
authors: Mohammad Hassan
authors: MH
authors: Khalili
authors: Assistant professor, Department of Orthodontics, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran.
authors: Sepideh
authors: S
authors: Torkan
mesh_terms: D000328:Adult; D001291:Attitude of Health Personnel; D001294:Attitude to Health; D003815:Dentists / Q000523:psychology; D004955:Esthetics, Dental; D005260:Female; D006801:Humans; D007180:Incisor / Q000033:anatomy & histology*; D008297:Male; D008334:Mandible / Q000033:anatomy & histology*; D000066794:Oral and Maxillofacial Surgeons / Q000523:psychology; D000066792:Orthodontists / Q000523:psychology; D023861:Photography, Dental / Q000379:methods; D011476:Prosthodontics; D012737:Sex Factors; D012904:Smiling; D013335:Students, Dental / Q000523:psychology; D055815:Young Adult