A new method for lateral pterygoid electromyographic electrode placement.
BACKGROUND
Making electromyographic recordings of the lateral pterygoid muscle (LP) is difficult because of potential electrode damage to, for example, the maxillary artery and long buccal nerve, and because of pain and reduced jaw mobility characteristic of many orofacial pain patients.


OBJECTIVE
The purpose of this study was to develop a reliable intraoral placement technique for the inferior head of the lateral pterygoid (IHLP) that minimizes jaw displacement.


METHODS
In 2 dried skulls and 7 human cadavers, it was estimated that, with the mandible in an ipsilateral closed position, a straight needle could be used to position fine-wire electrodes into the midportion of IHLP by inserting the needle through the mucosa adjacent to the distal root of the maxillary second molar, towards the external auditory meatus and parallel to the buccal alveolar bone of the maxilla. The needle avoided the maxillary artery and long buccal nerve. Using this approach in 5 adults, 2 fine-wire electrodes were placed into the IHLP. Placement was verified by computer tomography (CT) and electromyography.


RESULTS
In all subjects, the ideal insertion depth to place the electrodes in the middle of IHLP was 29 mm.


CONCLUSIONS
This technique is a reliable method for IHLP electrode placement for patients with impaired jaw function, minimizing risk of damage to major structures.
Salame
Talal H
TH
Faculty of Dentistry, University of Sydney, Sydney, Australia.
Peck
Chris C
CC
Murray
Greg M
GM
D000328:Adult; D002102:Cadaver; D004566:Electrodes; D004576:Electromyography / Q000295:instrumentation / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009339:Needles; D011626:Pterygoid Muscles / Q000502:physiology*