Masseter muscle tension and chewing ability in older persons.
OBJECTIVE
Mastication is an important function to maintain, not only for oral health, but also for quality of life. An easy-to-use method to evaluate the chewing ability of elderly people in any environment is necessary. Few studies have discussed the effectiveness of the masseter muscle by palpation. The purpose of this study was to clarify the availability of masseter muscle tension assessment methods by investigating its relationship with oral health status, and comparing it with other methods of assessing chewing ability.


METHODS
This cross-sectional study was carried out with 547 community-dwelling elderly subjects (246 men and 301 women; mean age 73.8 ± 6.2 years) who participated in a comprehensive annual geriatric health examination in 2010 at Kusatsu, Gunma, Japan. Chewing ability was evaluated by masseter muscle tension palpation, differences of masseter muscle thickness, occlusal force, self-reported chewing ability, and the number of remaining and functional teeth. Masseter muscle thickness was measured by ultrasonography.


RESULTS
Masseter muscle thickness and occlusal force showed significant differences between males and females. The strength of masseter muscle tension palpation was significantly associated with men's occlusal force, masseter muscle thickness, the number of remaining and functional teeth, and self-reported chewing ability (P < 0.05). Female participants showed a significant association with occlusal force, masseter muscle thickness, the number of remaining teeth, and self-reported chewing ability and results of palpation (P < 0.05).


CONCLUSIONS
These results showed that the palpation of masseter muscle tension is a reliable and easy-to-use method to evaluate the chewing ability of elderly people.
Graduate School, Section of Behavioral Dentistry, Tokyo Medical and Dental University, Tokyo, Japan.
Yuki
Y
Ohara
Hirohiko
H
Hirano
Yutaka
Y
Watanabe
Ayako
A
Edahiro
Emiko
E
Sato
Shoji
S
Shinkai
Hiroto
H
Yoshida
Shiro
S
Mataki
D000368:Aged; D001732:Bite Force; D003430:Cross-Sectional Studies; D003679:Deglutition; D003817:Dentition; D005260:Female; D015577:Geriatric Assessment; D006304:Health Status; D006801:Humans; D057187:Independent Living; D008297:Male; D008406:Masseter Muscle / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000502:physiology*; D008409:Mastication / Q000502:physiology*; D009129:Muscle Tonus / Q000502:physiology*; D009909:Oral Health; D010173:Palpation; D015203:Reproducibility of Results; D057566:Self Report; D012737:Sex Factors; D013997:Time Factors; D014463:Ultrasonography