[Profile modifications induced by orthodontic forces studied by an analysis of the nasolabial angle]

The authors have studied the development modifications of the facial profile subsequent to the different types of headgear focusing attention on the nose-labial angle variations. This study has evaluated separately the orthopedic action of the headgear measuring the variations of the columella inclination as regards the Frankfurt horizontal plane and the orthodontic action measuring the variation of the filter inclination as regards the Frankfurt horizontal plane. The study of the profile pictures of 20 patients in II Class I division treated with extra-oral traction and edgewise therapy showed that; while the high headgear determined a slight change of growth orientation in the nasal component of the nasal-jaw complex directing it upwards; the cervical headgear instead; determined a considerable descent of the nose with a consequent anti-aesthetic result.