title: Electromyographic evaluation of the 'vertical' dimension: the Learreta TMJ decompression test.
abstract: The clinical observation of the incisors overbite is the most common form used to evaluate the occlusal vertical dimension (OVD); however, this technique offers poor information about the compression state of the TMJ. In order to obtain such information, it is necessary to evaluate the electrical activity of the elevator muscles using surface electromyography (EMG). In case of a compressive irritation of the joint receptors, the trigeminal nucleus returns an inhibitory motor response of the elevator muscles that can be measured. The Learreta's EMG decompression test is done by measuring the EMG response of the masticatory muscles at maximal occlusion in four different OVD positions in such a way that the reduction of the TMJ pressure, and subsequently, relief of the inhibitory motor response can be studied. The aim of this study is to illustrate this technique, its clinical use and its limitations.
authors: UniFacs, the University of Salvador, Brazil.
authors: Marcelo
authors: M
authors: Freire Matos
authors: Andreas C
authors: AC
authors: Durst
authors: Jane Luzia
authors: JL
authors: Freire Matos
authors: Jorge Alfonso
authors: JA
authors: Learreta
mesh_terms: D001696:Biomechanical Phenomena; D001732:Bite Force; D004576:Electromyography / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D008334:Mandible / Q000473:pathology; D008406:Masseter Muscle / Q000294:innervation / Q000502:physiology; D008410:Masticatory Muscles / Q000294:innervation / Q000503:physiopathology*; D009046:Motor Neurons / Q000502:physiology; D009119:Muscle Contraction / Q000502:physiology; D018485:Muscle Fibers, Skeletal / Q000502:physiology; D009334:Neck Muscles / Q000294:innervation / Q000502:physiology; D009433:Neural Inhibition / Q000502:physiology; D009619:Nociceptors / Q000502:physiology; D010513:Periodontal Ligament / Q000294:innervation / Q000502:physiology; D011312:Pressure; D011434:Proprioception / Q000502:physiology; D013703:Temporal Muscle / Q000294:innervation / Q000502:physiology; D013704:Temporomandibular Joint / Q000294:innervation; D013705:Temporomandibular Joint Disorders / Q000175:diagnosis*; D014278:Trigeminal Nuclei / Q000503:physiopathology; D014716:Vertical Dimension