Influence of bite force and tongue pressure on oro-pharyngeal residue in the elderly.
OBJECTIVE
To investigate the influence of maximal bite force, maximal tongue pressure, number of mastications and swallowing on the oro-pharyngeal residue in the elderly.


BACKGROUND
Oro-pharyngeal residue in the elderly is an indication of dysphagia. Pharyngeal residue is especially critical as it may cause aspiration pneumonia, which is one of the major causes of death in elderly.


METHODS
Videofluorographic recordings were performed on 14 elderly volunteers (six males, eight females, age range 65-93 years) without any history or symptoms of dysphagia. The subjects were instructed to consume 9 g of barium containing bread in two manners; free mastication and swallow (FMS: masticate and swallow freely), and limited mastication and swallow (LMS: swallow once after 30 chewing actions). The amount of oral and pharyngeal residue was evaluated using a 4-point rating scale. Maximal occlusal force was measured by a pressure sensitive sheet, and maximal tongue pressure using a handy probe. Multiple regression analysis was performed to examine the influence of these items on the amount of oral and pharyngeal residue in FMS and LMS.


RESULTS
In FMS, age was found to be a factor which increased oral residue (p = 0.053), and the number of swallowing (p = 0.017) and the state of the prosthesis (p = 0.030) reduced the pharyngeal residue. In LMS, tongue pressure was a factor which reduced oral residue (p = 0.015) and increased pharyngeal residue (p = 0.008).


CONCLUSIONS
It is suggested that in the elderly tongue pressure contributed to propulsion of the food bolus from oral cavity into the pharynx, and multiple swallowing contributed to the reduction in the amount of pharyngeal residue.
Ono
Takahiro
T
Division of Oromaxillofacial Regeneration, Osaka University Graduate School of Dentistry, Suita, Japan.
Kumakura
Isami
I
Arimoto
Mayumi
M
Hori
Kazuhiro
K
Dong
Juan
J
Iwata
Hisayuki
H
Nokubi
Takashi
T
Tsuga
Kazuhiro
K
Akagawa
Yasumasa
Y
D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001732:Bite Force; D003679:Deglutition / Q000502:physiology; D003680:Deglutition Disorders / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D008409:Mastication / Q000502:physiology; D010865:Pilot Projects; D012044:Regression Analysis; D014059:Tongue / Q000502:physiology*