Tsutomu Ishijima

Osteoporosis and reduction of residual ridge in edentulous patients.

The relationship between the height of the mandibular residual ridge and the severity of osteoporosis in elderly edentulous patients was investigated. The height of the mandibular residual ridge was measured by use of the mental foramen on panoramic radiographs. The severity of osteoporosis was determined by examining frontal and lateral radiographs of the vertebrae. All of the patients received a blood analysis. The correlation coefficient between age and the height of residual ridge was -0.38, which was statistically significant (p < 0.01). The residual ridge in women was lower than that of men, showing a statistical significance (p < 0.01). The correlation coefficient was -0.42 between degree of severity of osteoporosis and the height of the residual ridge, which was significant (p < 0.01). The parathyroid hormone level was high in the patients with a low residual ridge, and the calcitonin (CT) level was low. This study indicates that osteoporosis strongly affects reduction of the residual ridge in edentulous patients.

Tongue motor skills and masticatory performance in adult dentates, elderly dentates, and complete denture wearers.

STATEMENT OF PROBLEM For complete denture wearers the tongue plays an important role in the retention and stability of dentures and has a great influence on masticatory function. PURPOSE OF STUDY The purpose of this study was to elucidate the relationship between tongue motor behavior and masticatory function. MATERIAL AND METHODS Thirty healthy, normal adult dentates, 10 normal elderly dentates, and 20 complete denture wearers whose dentures were constructed by the same methods and materials were selected. Tongue motor skills were examined by an ultrasound system and masticatory performance was evaluated by the sieving method. RESULTS The tongue motor skills of elderly dentates and complete denture wearers were statistically lower compared with those of adult dentates (p < 0.05, Duncan test). Tongue motor skills of complete denture wearers were statistically correlated with age (p < 0.01). Masticatory performance was statistically lower in relation to age in complete denture wearers (p < 0.01). The correlation coefficient was 0.74 between tongue motor skill and masticatory performance in complete denture wearers, which was statistically significant (p < 0.01). CONCLUSION Age-related decreases in tongue motor skills and masticatory performance were demonstrated by ultrasound observations and sieving methods.