Influence of age and gender on trigeminal sensory function and magnetically evoked masseteric exteroceptive suppression reflex.
OBJECTIVE
The present study explored the effect of age and gender on trigeminal sensory function and masseteric exteroceptive suppression (ES) reflex responses.


METHODS
Young healthy men (n = 12) and women (n = 12) (age: 23.5 ± 3.0 years) and older healthy men (n = 12) and women (n = 12) (age: 58.5 ± 5.2 years) participated. Sensory function was assessed on the skin overlying the mental foramen using mechanical stimuli. Surface EMG was recorded from the left masseter muscle to assess ES reflex responses evoked by a magnetic stimulus applied to the skin above the left mental nerve.


RESULTS
The older group had significantly higher tactile detection thresholds. Early ES1 was present in all subjects. Onset latency of ES1 was significantly delayed in older subjects. ES2 was present in all young subjects, but only in 5 of the 12 men and 8 of the 12 women in the older group. Significant gender differences were found for sensory and pain thresholds to mechanical stimuli as well as for duration of ES.


CONCLUSIONS
Ageing affects tactile detection thresholds, onset latency of ES1 responses, and appearance of ES2. The present results indicate that trigeminal sensory function and brainstem reflex responses differ between genders and age groups. These findings may have implications for assessment of craniofacial pain conditions.
Department of Oral Function and Rehabilitation, Nihon University School of Dentistry at Matsudo, 2-870-1 Sakaecho-nishi, Matsudo, Chiba 271-8587, Japan. komiyama.osamu@nihon-u.ac.jp
Osamu
O
Komiyama
Ryoko
R
Obara
Takashi
T
Iida
Kelun
K
Wang
Peter
P
Svensson
Lars
L
Arendt-Nielsen
Antoon
A
De Laat
Misao
M
Kawara
D000328:Adult; D000367:Age Factors; D005260:Female; D006801:Humans; D008297:Male; D008406:Masseter Muscle / Q000294:innervation* / Q000502:physiology; D008875:Middle Aged; D012018:Reflex / Q000502:physiology*; D012677:Sensation / Q000502:physiology*; D012684:Sensory Thresholds / Q000502:physiology*; D012737:Sex Factors; D055698:Touch Perception / Q000502:physiology*; D014276:Trigeminal Nerve / Q000502:physiology*; D055815:Young Adult