Relationship between the curve of spee and cranio facial morphology

The aim of this study was to investigate the relationship between the curve of Spee and cranio facial morphology. 

Dental casts and lateral cephalograms were obtained from 61 orthodontic patients. The subjects were divided into five groups with Class I, Class II Division 1, Class II Division 2, Class III, and open bite. The cephalometric analysis aimed to evaluate the sagittal and vertical craniofacial dimensions as well as the position of the mandibular condyle with respect to the occlusal plane, dental measurement, soft tissue measurement. These variables were assessed by means of one way analysis of variance (ANOVA), a post hoc Tukey HSD comparison tests. Correlation was evaluated by Spearmen correlation. 

The amount of the curve of Spee was significantly related to SN-Go Gn angle and anterior facial height; the maxillo mandibular difference and ANB, the horizontal position of the condyle with respect to the dentition, the measurement of lower incisor protrusion, and the measurement of lower lip protrusion . 

The curve of Spee is highly variable between individuals and influenced by malocclusion type and craniofacial morphology.