Removable Prosthodontics Section Editors

T individuals rendered edentulous and provided with complete dentures display marked changes in jaw relations due to resorption of the residual alveolar ridges. The changes are characterized by an upward rotation of the mandible with a resulting decrease in occlusal vertical dimension and increase in mandibular prognathism. I-3 The most rapid changes occur during the first year, when the rate of resorption is greatest. It may be assumed that the changes in oral conditions and jaw relations while complete dentures are worn can affect the hyoid bone position and also possibly influence craniocervical relations. No systematic analyses of gradual changes in these functional relations in denture wearers appear to have been reported. In younger dentulous groups, studies have been made on changes in location of the hyoid bone during retruded contact, intercuspal, and postural positions of the mandible,4 and on changes in hyoid position related to orthodontic treatment of mandibular prognathism.J The effect of osteotomy on hyomandibular-cervical relations has been studied in patients with mandibular protrusion.6s7 The craniocervical postural relations were examined by Solow and TallgrerP” in a series of radiographic cephalometric studies of young adults. The findings indicated that the posture of the head and cervical column is associated with morphologic characteristics of the facial skeleton’O and with dentoalveolar rela-