Functional disorders of the stomatognathic system include dysfunctions leading to pathological increase of the occlusal forces generated by mandibular adductors. High values of these forces are the cause of numerous disorders within the masticatory organ such as pathological abrasion of the teeth, tension headaches and pain in the region of the temporomandibular joints. The aim of this study was assessment of occlusal forces in the course of the therapy of painful types of functional disorders with the use of botulinum toxin type A - the drug causing muscle relaxation. The material for the study comprised adult patients aged 24-42 years who presented with a painful type of functional disorders in the University Hospital, Institute of Dentistry Jagiellonian University Medical College in Cracow. The patients were qualified to the study on the basis of the results of specialist functional examination of the masticatory organ in which additionally the VAS (Visual Analogue Scale) was used for pain assessment of the masseters and temporomandibular joints. The measurement of maximal occlusal forces in the examined patients was carried out in all patients in the region of the central incisors and first molars on the both side with the use of a special measuring instrument for dental examination, specially constructed (patent number P 334933). The examinations were performed before the beginning of the treatment, 10 days and 16 weeks after intramuscular administration of botulinum toxin type A at a dosage of 21 mouse units - U for one masseter. The results of the examination of maximal occlusal forces obtained in the first examination, that is, before the beginning of the treatment, markedly exceeded the physiological values. In the control examinations, significant, persistent decrease of studied forces has been noted.
