Objective:

 The purpose of this investigation was to undertake an objective and quantitative evaluation of how severity of lower anterior face height (LAFH) variations influences perceived attractiveness.

 Design:

  Cross-sectional study

  Setting:

  St George’s Hospital, London, UK

 Participants and methods:

 The LAFH of an idealized male and female frontal facial image were altered in 2·5 mm increments from −20 to 20 mm (male images) and from −10 to 20 mm (female images), in order to represent reduction and increase in height of this region. These images were rated by a pre-selected group of pre-treatment orthognathic patients (n = 75), clinicians (n = 35) and laypersons (n = 75).

 Outcome measures:

  Ratings on a seven-point Likert scale.

 Results:

  With an increase in LAFH, desire for surgery became significant at 15–16 mm for male faces and 13–14 mm for female faces. With a reduction in LAFH, desire for surgery became significant at −14 to −17 mm for male faces a smaller reduction of −6 to −8 mm led to a significant desire for surgery for female faces.

 Conclusions:

  The classical vertical facial trisection canon of upper face height as one-third (33·3%), midface height as one-third (33·3%) and LAFH as one-third (33·3%) of total anterior face height may be used as an ‘ideal’ proportional ratio. Mild LAFH variations were largely acceptable. In terms of the percentage LAFH to total anterior face height (TAFH) and anterior face height (AFH), observers did not desire surgery for LAFH variations of 25–42% of TAFH (40–66% of AFH) for male faces, and 28–42% of TAFH (45–66% of AFH) for female faces.

 Source: Journal of Orthodontics

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