Identificador: TDX:504
Autors: Forteza González, Gabriel
Resum:
INTRODUCTIONIn the current literature, Masticatory Myofascial Pain Syndrome (MMPS), affects even 25% of general population. It affects mostly women (75-88,5%) from 20 to 40 years old. Main symptoms are trismus, facial pain, weakness and limitation of function in masseter (79-84%) and temporal (56-65%) muscles, followed by internal and external pterygoid and digastric muscles. Sternocleidomastoid, Splenius, Trapezius, perioral and frontal muscles can be also painful. Masseter complaint characteristically presents a taut or trigger band, localized in the middle of the muscle, painfull on palpation. MMPS often associates to depression, anxiety, and sleep disorders.Current literature on chronic pain considers that masticatory MMPS is due to central and peripheral mechanisms of Neuromuscular System, like MPS of trunk and limbs, though its exact origin is still uncertain. Different theories associate an excess of muscle activity, with final toxic metabolites release. Predisposing factors are bad body postures, sedentary life, nutritional imbalance- especially vitamin deficiency-, parafunctional habits, sleeps disorders and joint disorders.Most often, MMPS therapy has included prolonged use of non esteroidal anti-inflammatory agents, oclusal splints, muscle relaxants, antidepressives, or physical and behavioral therapies. Demonstrated useful local treatments are dry needling and infiltration of diverse agents, including physiologic saline solution. Hypothesis: Botulinum Toxin is an effective therapeutic method in MMPS.Objectives: To evaluate efficacy, side effects, of Botulinum Toxin A (BTA) in a group of voluntary patients affected of MMPS, by means of a parallel, double-blind, randomized study.MATERIAL AND METHODSA prospective, uni-centric, randomized, controlled, and double-blind study was designed to evaluate the efficacy of BT in the treatment of MMPS. Patients who accepted to be involved in the study were left to the Multiaxial Clinical Inventory (Millon II) to evaluate their personality. From September 2001 to September 2002, 72 patients accepted to be involved in this study. Diagnosis of MMPS was based on Dworkin and LeResche Research Diagnostic Criteria for Temporomandibular Disorders (RDCTMD) corresponding to muscular disorders (group I), for MMPS. Thirty patients were randomly selected and distributed in two groups:· BT· PlaceboPatients in both groups filled a questionnaire about pain and side effects of treatment. Pain was measured using Visual Analogical Scale (VAS) before, 2, 4, 8 and 16 weeks after treatment. Maximal not assisted interincisal aperture was also measured. Study group was treated by injecting BT A (Botox®) in masseter and temporal muscles, both sides, in five different points. Control group was treated by injecting saline solution using the same distribution than study group. RESULTSBoth groups showed a near normal mouth opening (39,6 for BT group and 37,3 placebo. Pain was found in all masseter, and in half of the temporal muscles, approximately.Pain. Global improvement was significant in both groups (p<0,001), but there was no difference between them.Side effects. Twelve of 13 patients, that is, 87,5%, treated with BTA showed a marked loss of efficiency and weakness sensation on chewing.CONCLUSIONSBTA has the same analgesic efficacy than placebo. Analgesic response to global and active pain has statistical significance and is maintained along 16 weeks. In conclusion, BTA is effective in treatment of MMPS, as much as placebo. These results imply the presence of a local physical effect at the level of trigger points or bands like dry needling or simply, placebo.
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