EFFECT OF DENTURE SEARING ON FACIAL MORPHOLOGY - A 7-YEAR LONGITUDINAL STUDY

A longitudinal roentgenographic cephalo-metric study was performed in order to evaluate the effect of a 7-year period of denture wear on the skeletal morphology of the jaws and face. The test subjects comprised 11 individuals provided with complete dentures (mean age 47 years) and 11 individuals with a full upper and a partial lower denture (mean age 42 years). The cephalo-metric analysis comprised the following stages of observation: before extraction, after prosthetic treatment and after 7 years of denture wear. The method errors were determined for cephalometric linear and angular variables and for the measurements of the areas of resorp-tion, performed by planimeter. The edentulous alveolar processes responded most markedly to the 7-year period of denture wear. In the complete denture wearers the mean reduction in height of the mandib-ular process, as measured in the anterior region, was 6.6 mm and approximately 4 times greater than that of the maxillary process. The mean of the resorption areas of the mandibular symphysis was 50 mm2. The partial denture wearers displayed a somewhat greater resorption of the edentulous maxillary process than the complete denture wearers, the difference between the groups not being significant, however. The dentulous mandibular process in the partial denture wearers exhibited no appreciable reduction. The resorption of the alveolar processes caused a decrease in mandibular inclination (anterior rotation) with a resulting reduction in total face height and an increase in mandibular prognathism. Despite the marked resorption of the alveolar processes and resultant changes in jaw relationship, especially marked in the complete denture wearers, the cranial base, the upper facial structures and the basal parts of the mandible, including the gonial angle, were found unaffected.