Maximal bite force and surface EMG in patients with myasthenia gravis

Masticatory muscle strength was quantified in patients with bulbar myasthen ia gravis and compared with that of patients with ocular myasthenia gravis, patients in clinical remission (whether or not pharmacological) who previo usly suffered from bulbar myasthenia gravis, and healthy subjects. Maximal bite force and maximal activity of the masseter and temporalis muscles and of the submental muscle complex were measured. Bite force was decreased in the patients with bulbar myasthenia gravis, but was normal in the patients in the clinical remission group and in the ocular group. These findings wer e consistent with the results of electromyographic data. Although subjectiv e reports of masticatory muscle weakness provide valuable information, quan titative measurements provide more information about the degree of muscle w eakness of individual muscles. This is especially important for longitudina l evaluation of therapy in individual patients and for pharmacotherapeutic research. (C) 2000 John Wiley & Sons, Inc.