Development and application of reflexodent in the quantitative functional evaluation of chewing control in patients with temporomandibular joint dysfunction and a control group.
BACKGROUND
There has been controversy with respect to the diagnostic value of the inhibitory masseteric reflex in temporomandibular joint dysfunction (TMJD) because the whole reflex response was not considered. The purpose of this study was to characterize the reflex changes that occur in patients with different levels of TMJD and in a control group.


METHODS
Eighty-nine patients (ages 31.14 +/- 12.74 years) divided into three groups were studied and compared. The control group was without TMJD (n = 30), with moderate symptoms (n = 30), and with severe symptoms (n = 29). Using an instrument and a software program developed by our group (Reflexodent), the masseteric inhibitory reflex was studied. The electromyography record (EMG) was captured with surface electrodes and the inhibitory reflex was produced by tapping the chin. The EMG signal was processed, filtered, and averaged with the Reflexodent. Twenty series of records were applied to each patient. The faulty inhibitory area, the area's relation (potentiation/inhibition) regarding the values of healthy subjects previously characterized, and the bilateral symmetry were measured.


RESULTS
Discriminate analysis showed a statistically significant correlation between clinical groups and electromyographic findings. Statistical function explained 91.8% of the discrimination among groups (canonical correlation = 0.918, chi(2) = 164.435, p <0.001).


CONCLUSIONS
The study of whole inhibitory masseteric reflex and the Reflexodent technique are useful as a diagnostic tool to evaluate TMJ illness in the dental clinic.
Angeles-Medina
F
F
Facultad de Odontología, Universidad Nacional Autónoma de México (UNAM), México, D.F., Mexico.
Nuño-Licona
A
A
Alfaro-Moctezuma
P
P
Osorno-Escareño
C
C
D000328:Adult; D000367:Age Factors; D003936:Diagnosis, Computer-Assisted; D004576:Electromyography; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D008297:Male; D008406:Masseter Muscle / Q000503:physiopathology; D008409:Mastication / Q000502:physiology*; D008875:Middle Aged; D012021:Reflex, Abnormal; D012720:Severity of Illness Index; D012815:Signal Processing, Computer-Assisted; D012984:Software; D013705:Temporomandibular Joint Disorders / Q000175:diagnosis* / Q000503:physiopathology