Aim The submental-cervical angle may alter as a result of mandibular orthognathic surgery and/or the ageing process and is therefore an important facial aesthetic parameter for comparative diagnosis and treatment planning. The purpose of this study was to undertake a quantitative evaluation of the influence of the submental-cervical angle on perceived attractiveness and threshold values of desire for surgery. Study Design The submental-cervical angle of an idealized profile silhouette image was altered incrementally between 90°and 130°. The images were rated on a sevenpoint Likert scale by pre-treatment orthognathic patients (n = 75), laypeople (n = 75), and clinicians (n = 35). Results A submental-cervical angle of 90°-105°was deemed acceptable. Angles up to 120°were deemed slightly unattractive by the lay and clinician groups, but very unattractive by the patient group. By 125°-130°all groups perceived the angle as very unattractive. The threshold value of desire for surgery was 110°for patients, 115°for lay people and 125°for clinicians. Patients appear to be more critical than lay and clinician groups. Conclusions These ranges of normal variability of the submental-cervical angle and threshold values of desire for surgery, in terms of observer acceptance, should be considered by clinicians in planning mandibular orthognathic surgery and aesthetic surgical procedures of the submentalcervical region.