Head angulation and variations in the maxillomandibular relationship. Part I: The effects on the vertical dimension...

A study of a small patient sample sought to assess the effects of head angulation on the vertical dimension of occlusion. In some patients, increasing the head angulations showed a positive tendency of displacement, whereas in others the displacements were negative. Most displacements were mixed and irregular. A mathematical analysis revealed no correlation and no significance in the relationship of displacement versus the progressive changes in head angulation. The tested hypothesis was that the vertical dimension of occlusion would increase (or progressively alter) as the angulation of the head was progressively increased. Twelve attempts failed to produce a recognizable and mathematically acceptable pattern of distortion. This experiment failed to support the widely held hypothesis that the patient should be seated in an upright position to prevent distortion of the recording of VDO. It appears that the best recommendation for patient posture during the establishment of the maxillomandibular relationship is one that is comfortable for the patient and is easy for the dentist to obtain the recording.