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Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: OBJECTIVE, METHODS, RESULTS. Meshes: Adolescent, Adult, Case-Control Studies, Dentofacial Deformities, Electromyography, Female, Humans, Jaw, Male, Masseter Muscle, Orthognathic Surgery, Pain Measurement, Reflex, Stretch, Surveys and Questionnaires, Temporal Muscle.
user
Is jaw-stretch reflex weaker in patients after orthognathic surgery? Context: The jaw-stretch reflex (JSR) was studied in both patients and healthy participants in order to investigate the possible long-term impact of orthognathic surgery on the motor function of the masticatory system. JSR was measured in patients before surgery (PC), 1year after surgery (PS) and in healthy controls (HC) (N=31 in each group). JSR was evoked by a standardized stretch device and recorded bilaterally from masseter and anterior temporalis muscles using surface electromyography (EMG). The peak-to-peak amplitude (which was normalized to pre-stimulus EMG activity) of JSRs in PC and PS were significantly smaller than in HC (P<0.001; P<0.001). The onset latency in PS was significantly longer compared with HC (P<0.05). The duration of JSR in PS was significantly longer than in HC and PC (P<0.001; P<0.05).
assistant
Patients with dentofacial deformities are characterized by reduced JSR amplitude. The delayed onset and elongated duration of JSR might be potential indicators of a long-term surgical impact on the motor function of the masticatory system. Final Decision: yes