Influence of lower complete denture use on masseter muscles and masticatory function: A longitudinal study.

BACKGROUND: Edentulism can reduce mastication, leading to changes in food pattern, with possible consequences to masticatory muscle thickness. OBJECTIVES: This study verified masticatory function and oral perception in subjects who did not use lower CDs, and whether the insertion of new upper and lower CDs would improve such variables. METHODS: Fifteen edentulous elderly who wore only the upper CD were selected and received new upper and lower CD. Volunteers were evaluated at baseline and after 1, 3 and 6 months of new prosthesis use. Masticatory performance (MP) was assessed by the sieving method (X50 values). Masseter thickness (MT) was evaluated by ultrasonography. Oral sensorial ability (OSA) was assessed by oral stereognosis test and maximum tongue pressure (MTP) was verified by pressure sensors. Data were submitted to repeated measures ANOVA and Tukey-Kramer posthoc tests (α = 0.05). Correlation between OSA and MTP was verified by Person's correlation. RESULTS: X50 and MTP decreased (P < 0.05) after 1 month and remained stable (P > 0.05) for next assessments. After 3 months, MT in rest position was increased (P < 0.05), while during maximum voluntary contraction 1 month was enough to increase MT (P < 0.05). There were no differences for OSA (P > 0.05) and no correlation between OSA and MTP. CONCLUSION: Masticatory performance and masseter thickness of elderly who did not use the lower dentures were improved after 2 months using new upper and lower CDs. However, new CDs in both dental arch decreased MTP. Brazilian Registry of Clinical Trials (ReBEC #RBR-37gdst).

Understanding the impact of taste changes in oncology care.

PURPOSE: Taste perception is frequently altered in cancer patients. The purpose of this review is to provide an update on advances in understanding of the basic biology and physiology of taste and how taste and flavor may be impacted in cancer and its treatment. METHODS: A succinct review of the literature on the biology and neurology of taste, taste evaluation, and the impact in oncology is provided. RESULTS: Advances have occurred in the study of the gustatory system. Taste and smell are commonly affected during cancer care, and specific chemosensory complaints may persist in large numbers of cancer survivors. Limited study in oncology patients is available despite the significant impact that taste and smell have on oral intake and general physical and social well-being. CONCLUSIONS: Taste and flavor has had limited study in cancer therapy. Impact on taste and flavor can result in changes ranging from elimination of taste to taste distortions that may be associated with taste aversions, nausea, and dietary compromise. New therapeutics and new approaches in oncology may have additional impact upon taste that requires further study. This paper reviews the current understanding of taste function, taste testing, and its potential impact on cancer care, to serve as a guide for directing further research.

Vibration perception thresholds of human vital and nonvital maxillary incisors.

OBJECTIVE: Vibrations applied to human teeth have been shown to induce vibrotactile sensations although the location of the mechanoreceptors responsible for encoding vibrations is unclear. The aim of this study is to test the hypothesis that vibrotactile tooth sensations depend on afferent input from intradental mechanoreceptors. DESIGN: Vibration perception thresholds were determined for a vital (control) and a contralateral nonvital (endodontically treated) maxillary incisor in 11 healthy human participants using an adaptive psychophysical procedure. An electromechanical vibrator was used to deliver sinusoidal vibrations at 10 frequencies between 40 and 315 Hz. RESULTS: The median force thresholds ranged between 41 and 215 mN for vital and 71 and 507 mN for nonvital incisors. Nonvital median force thresholds were significantly higher than vital thresholds at all frequencies between 40 and 315 Hz. A linear regression analysis revealed a significant increase in vibrotactile thresholds with increasing frequency for only the vital incisors. CONCLUSIONS: The results support the hypothesis that mechanoreceptors located within the tooth contribute to vibrotactile tooth sensations and that mechanosensory information from both periodontal ligament and intradental mechanoreceptors facilitates the accurate assessment of food textures during mastication.