The Research Of Cervical Vertebrae Posture Differences Of Patients With Different Vertical Facial Types

Abnormal vertical dimension is one of the most common maxillofacial developmental anomalies and it affected oral function as well as maxillofacial aesthetics greatly, additionally, there are different orthodontic treatment projects according to the different ages. In the process of correcting abmormal vertical dimension, we often found that there is no obvious improvement of the maxillofacial aesthetics, especially the lateral features'harmony after the correcting treatment; in the same time, we can not keep the treatment result sustainable and stable. In the clinical studies we also found that, the relationship between maxillofacial structure and head posture as well as cervical vertebrae vertebrae posture is close, they are dominated by the same neural and muscle electrical activity system, what's more, they influences each other.Objective:To study the characteristics and differences of patients'cervical vertebrae posture with different vertical facial types for improving the lateral features' harmony and maintaining the long-term stability of the treatment effects after correcting process of abnormal vertical dimension, additionally, to provide some references for the research of growth of craniofacial structure and cervical vertebrae.Methods:Lateral cephalometric radiographs at natural head posture of 226 children and adults with different vertical facial types were retrospectively investigate by computerized cephalometric analysis, cervical vertebrae posture of children and adults was compared among different vertical facial type groups separately.Results:In three vertical facial types of children and adults, there are no statistical differences in CVT-OPT,SN-CP,SN-OPT and SN-CVT between male and female.Children: there are no statistical differences in CVT-OPT,SN-CP,SN-OPT and SN-CVT among low-angle face group, average-angle face group and high-angle face group, but from low-angle face group, average-angle face group to high-angle face group, the tendency of CVT-OPT is decreasing by degrees and the tendency of SN-CP,SN-OPT,SN-CVT are increasing by degrees.Adults: there were statistical differences in CVT-OPT between the low and high-angle face group and between the average and high-angle face group, the CVT-OPT in high-angle face group decreased significantly than that in low-angle face group and in average-angle face group, there were no statistical differences in CVT-OPT between the low and average-angle face group; there were statistical differences in SN-CP among three groups, low-angle face group﹤average-angle face group﹤high-angle face group; there were statistical differences in SN-OPT and SN-CVT between the low and high-angle face group, low-angle face group﹤high-angle face group, but there were no statistical differences between the low and average-angle face group and between the average and high-angle face group.Conclusions:In the malocclusion deformity of skeletal Class I sagittal position, different vertical facial type has a link with cervical vertebrae posture, especially between the low and high-angle face group of the adults, the head position and cervical vertebrae posture has been characteristic changed.The different vertical dimension growth of maxilla and mandible may be related to head position and cervical vertebrae posture, the causality remains to further study. For the malocclusion deformity patients with abnormal vertical dimension who has the continually growth potential, we should interdict the abnormal growth direction, in order to create conditions for the establishment of normal equilibrium of the masticator muscle system and muscles around the neck.