Chapter 7 Hasund Dental Harmony Assessment

D. Segner and A. Hasund (1991) proposed the «super-harmo-ny» method as well as the Kephalo-Zet device for its implementation. The method is based on the concept of «shifting shapes» and «leading variables» and is recommended for diagnosing facial skull abnormalities. Hasund method allowed to establish that with harmonious jaw development, anomalies of occlusion of the dentition have dental-alveolar forms and require in terms of treatment either growth modification at the level of the dentition (extension, lengthening, shortening) or dental-alveolar compensation associated with the

movement of teeth along the dental arch or with changes in the size of the dentition. These anomalies are usually treated without removing certain teeth.

In the case of anomalies of dental occlusion in the case of non-harmonious development of the jaws - a skeletal form of occlusion anomaly - modification of the growth of the dentitions and jaw bones (shift, enlargement, reduction), as well as dental-alveolar compensation, often with the removal of selected teeth is required. Modification of the jawbone growth is performed only in patients who have not completed skeletal growth.

Analysis of head TRGs performed in lateral projection according to the Hasund (1991) method makes it possible to determine the harmony (proportionality) of the facial skull. The following parameters are considered for this purpose:

1. SNA - the angle is normally 82 degrees and characterizes the position of the anterior point of the apical base of the maxilla in relation to the anterior part of the skull base (Fig. 7.1). An increase in the angle is upper prognathism, and a decrease in the angle is upper retrognathism.