In the treatment of patients with an oro-facial anomaly, the functioning of the masticatory system and aesthetic aspects play a role. Recently, the software programme ‘Facial Harmony’, which analyzes the soft tissue contour of the face, appeared. Using this programme, a research project was carried out to find out if the result of the surgical treatment of 40 patients with an oro-facial anomaly satisfied the facial harmony requirements. Only 65% of the treatment results met the requirements. It was especially the patients who had been treated for mandibular deficiency with mandibular and horizontal lines meeting at a wide angle who showed no facial harmony. Only 30% of those patients demonstrated facial harmony postoperatively. If the surgical treatment had been completed by a genioplasty, this percentage would very probably have risen to 85.