Chewing-induced regional brain activity in edentulous patients who received mandibular implant-supported overdentures: a preliminary report.
OBJECTIVE
We used functional magnetic resonance imaging (fMRI) to investigate the change in brain regional activity during gum chewing when edentulous subjects switched from mandibular complete dentures to implant-supported removable overdentures.


METHODS
Four edentulous patients (3 males and 1 female, aged 64 to 79 years) participated in the study. All subjects received a set of new maxillary and mandibular complete dentures (CD), followed by a maxillary complete denture and a new mandibular implant-supported removable overdentures (IOD). A 3-T fMRI scanner produced images of the regional brain activity for each subject that showed changes in the blood-oxygenation-level-dependent (BOLD) contrast in the axial orientation during gum-chewing with CD and IOD.


RESULTS
Region-of-interest analysis showed that IOD treatment significantly suppressed chewing-induced brain activity in the prefrontal cortex. The chewing-induced brain activities in the primary sensorimotor cortex and cerebellum tended to decrease with IOD treatment, however they did not reach to significance level. There was no change in brain activity in the supplementary motor area, thalamus and insula between gum chewing with CD and IOD. Group comparison using statistical parametrical mapping further showed that, within the prefrontal cortex, the neural activity of the frontal pole significantly decreased during gum-chewing with IOD when compared to that with CD (P<0.05).


CONCLUSIONS
Despite the limitation of a small sample size, these results suggest that the gum-chewing task in elderly edentulous patients resulted in differential neural activity in the frontal pole within the prefrontal cortex between the 2 prosthodontic therapies-mandibular CD and IOD.
Division of Fixed Prosthodontics, Department of Oral & Maxillofacial Rehabilitation, Kanagawa Dental College, 82 Inaoka Yokosuka, Kanagawa 238-8580, Japan. kimotokt@kdcnet.ac.jp
Katsuhiko
K
Kimoto
Yumie
Y
Ono
Atsumichi
A
Tachibana
Yoshiyuki
Y
Hirano
Takero
T
Otsuka
Akinori
A
Ohno
Katsuhiko
K
Yamaya
Takayuki
T
Obata
Minoru
M
Onozuka
D000368:Aged; D001921:Brain / Q000502:physiology*; D002531:Cerebellum / Q000502:physiology; D015921:Dental Implants; D003824:Denture, Complete; D003828:Denture, Overlay; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008334:Mandible; D008409:Mastication / Q000502:physiology*; D008875:Middle Aged; D009066:Mouth, Edentulous; D010100:Oxygen / Q000097:blood; D017397:Prefrontal Cortex / Q000502:physiology; D013788:Thalamus / Q000502:physiology
D015921:Dental Implants; D010100:Oxygen