Study on the ideal sagittal position of the lower third of the face in high-angle patients with different forehead forms

Abstract

Objective To explore the ideal sagittal position of the lower third of the face in high-angle patients with different forehead forms and to provide a reference for clinical treatment. Methods Informed consent and portrait authorization were obtained from all patients, and the study passed the ethical review of the unit. We categorized forehead forms into four types: straight, rounded, type I angular (angled at the middle third of the forehead) and type II angular (angled at the upper third of the forehead). Profiles of high-angle patients with different forehead forms were collected. The initial position was when the facial axis point (FA point) was positioned at the goal anterior-limit line (GALL). After being silhouetted, the lower third of the face was moved forward and backward by 1 mm, 2 mm, 3 mm, and 4 mm each, plus the initial silhouetted picture, to obtain 9 images for each patient. A survey was created with these lateral profile silhouettes, and the silhouette images were ranked by 30 orthodontists and 30 laypersons. Results There were significant differences in profile scores at different movement distances of the lower third of the face among high-angle patients with different forehead shapes (P0.05). Conclusion The forehead forms and the sagittal position of the lower third of the face will affect the face’s profile aesthetics. Patients with straight and type Ⅱ angular foreheads has the best profile when the FA point is located on the GALL line. For patients with rounded and type Ⅰ angular foreheads, a posterior location of the lower third of the face is more desirable than the initial position.

Keywords

• forehead
• profile esthetic
• high angle
• skeletal class i
• position of incisor
• facial silhouettes
• orthodontics
• scoring system