The invention relates to medicine, in particular to neurology and dentistry and can be used for diagnosing neuromuscular disorders in children with maxillofacial anomalies.Summary of the method consists in that it is performed the electromyography using electrodes in the form of small disks on the surface of the skin in the region of the mastication and temporal muscles on both sides and is recorded the bioelectric activity at rest, for 10 min, then after the application of an exercise stress with maximum mandibular muscular contraction, for 10 s and after the relaxation of muscles, in 10 min after the exercise stress, in the event if the ratio between the value of normal bioelectric activity to the value of bioelectric activity, obtained from the patient with maxillofacial anomalies for the mastication muscle at rest is of 95…90%, after the application of the exercise stress is of 80…55% and after the relaxation of muscles is of 98…70%, and for the temporal muscle at rest is more than 110%, after the application of the exercise stress - 92…65% and after the relaxation of muscles - 111…94%, it is diagnosed the presence of neuromuscular disorders.