Comparison of Natural Head Position in Different Anteroposterior Malocclusions

Objective: The facial esthetics after orthodontic treatment and orthognathic surgery may be affected by the patient’s natural head position. The purpose of this study was to evaluate the natural head position for the three skeletal classes of malocclusion. Materials and Methods: Our sample consisted of 102 lateral cephalometric radio- graphs of patients aged 15 to 18 years; class I (n=32), class II (n=40) and class III (n=30). Nine landmarks of the craniofacial skeleton and three landmarks of the cer- vical vertebrae were determined. Variables consisted of two angles for cervical post- ure (OPT/Hor and CVT/Hor), three angles for craniofacial posture (SN/Ver, PNS- ANS/Ver, and ML/Ver ) and five for craniofacial angulation (SN/OPT, SN/CVT, PNS-ANS/OPT, PNS-ANS/CVT, ML/CVT). The data were analyzed statistically us- ing ANOVA and post hoc tests. Results: PNS-ANS/Ver and SN/Ver differed significantly (p<0.05) among the three groups. There were no significant differences between class I and class II malocclu- sions for the indicator angles of cranial posture except for ML/Ver. The SN/CVT was significantly different for class I compared to class III patients. A head posture ca- mouflaging the underlying skeletal class III was observed in our population. Conclusion: A more forward head posture was observed in skeletal class III partici- pants compared to skeletal class I and II and that class III patients tended to incline their head more ventral compared to class I participants. These findings may have im- plications for the amount of jaw movements during surgery particularly in patients with a class III malocclusion.