CEPHALOMETRIC STUDY OF CHANGES OCCURRING IN FACE HEIGHT FOLLOWING PROSTHETIC TREATMENT .I. GRADUAL REDUCTION OF BOTH OCCLUSAL AND REST FACE HEIGHTS

A roentgenographic cephalometric investigation was conducted on 18 patients to study changes occurring in occlusal face height, rest face height, and inter-occlusal clearance, before extraction of the teeth and during the first 12 month period following prosthetic treatment. The findings were as follows:1. The occlusal face height as determined by the swallowing technique after insertion of the dentures was significantly increased. This increase was followed by a gradual reduction, which was greater during the first six months than the second six months of wearing the dentures.2. The rest face height was reduced to a great extent when the remaining teeth or the occlusal stops were removed. After insertion of the dentures, it increased to a significant level. Again, this increase was followed by gradual reduction paralleling the reduction in occlusal face height.3. By the end of the 12 month period of wearing the dentures, the occlusal face height and rest face height were reduced to almost the same height that existed before the remaining teeth were extracted.4. The interocclusal clearance within each patient remained relatively constant during all phases of the study.5. The use of muscle function, rather than muscle rest during swallowing and phonetics, is recommended for the direct determination of the occlusal vertical dimension in edentulous patients.6. The rest position is unreliable for the clinical purpose of establishing occlusal vertical dimension in edentulous patients. It should be used only as a guide, but not as the means for this purpose.7. Periodic checkups are deemed necessary after the insertion of the dentures to correct changes in the supporting structures and the resulting occlusal discrepancies. © 1968 The C. V. Mosby Company.