Configurational differences in six skeletal landmarks in surgically treated and nonsurgically treated Class II patients.

Nongrowing patients with full-cusp Class II malocclusions can be treated with or without orthognathic surgery. The purposes of this retrospective study were to observe if skeletal factors influence treatment decisions and to investigate whether a discriminant analysis based on skeletal landmarks can be used to approximate the clinician's decisions. Information was obtained from the records of 44 postmenarchal women with a full-cusp Class II occlusion. Orthognathic surgery was suggested for 23 (52%) of the patients. They were on average 7 years older and presented with a greater maxillomandibular disharmony than the patients treated without surgery. Evaluation of the spatial relationships between the anatomic points by means of multidimensional scaling revealed that the shape of the triangle between articulare, supramentale (point B), and subspinale (point A) differed significantly between groups. For 33 of the 44 patients (75%), the clinician's decisions coincided with a linear discriminant function based on the spatial relationship of subspinale, supramentale, and articulare. These findings suggest that age as well as skeletal configuration played a role in the orthodontist's decision to use surgical or nonsurgical treatment.