SummaryPhysical therapy (PT) is a well-recognized, efficient conservative metho d for the management of pain and movement dysfunctions of musculoskeletal origin throughout t he body. In a lifetime, about 2/3 of the population presents jaw disorders (called tem poromandibular disorders, TMDs), as part of these musculoskeletal problems. Hence the o bjective of this PhD dissertation was to evaluate the effectiveness of PT for treating pain a nd movement dysfunctions in TMDs. Previous studies were reviewed using the Cochrane systematic review method.This review resulted in 28 randomized, controlled trials (RCTs) w ith a high variation in research methods, PT modalities and outcome variables. It showed that PT results in less pain, a better mouth opening and improved jaw function over time. Howeve r, comparisons between PT interventions and placebo interventions or with a control gro up without treatment were equivocal. Combinations of PT modalities seem to result in more dec rease of pain and impairment than single PT modalities but it was impossible to conclude w hich combination was more effective. A subsequent study analyzed the influence of study characteristics on th e degree of pain en mobility improvement, both before to after the PT treatment, and between the different PT treatments. Respectively, 70% and 63 % of the studies reported significa nt improvement before to after treatment for pain and mobility There is an increased ch ance on finding pain improvement after treatment if the follow-up is longer than 30 days, if more subjects are included in the study and if the subjects received real therapy (in co ntradiction to placebo treatment or no treatment). There is an increased chance on finding mobi lity improvement after treatment if subjects received real therapy and if they received more treatments. Making a judgement about the effectiveness of PT by means of a systemati c review also depends on the completeness of the included studies and the quality of t hese studies. Hence, we analyzed the effect of hand search on the number of identified studie s and the effects of four different quality assessment tools. An electronic search strategy i n the databases Pubmed, Embase and the Cochrane Central Register of Controlled Trials resulted i n 52 studies. The method of hand searching resulted in an extra 17 (25%) studies. The esti mated quality of the studies was different according to the different assessment tools used. An additional investigation of the association between publication year and the method ologcal quality of the studies resulted in a better quality for the most recent studies if asse ssed with the Delphi list, the Megens & Harris list and the Risk of Bias list. An important overall finding however was that the methodological quality of the studies appeared to be low. This shortcoming, inspired to conduct two long-term randomised controlled studies One study including patients suffering from masticato ry muscle pain and another study on patients with anterior disk displacement (closed lock) of the temporomandibular joint (TMJ). By means of validated measurements of pai n and mobility we analyzed the effect of PT. Patients willing to cooperate were randoml y assigned to either a PT group or a control group. All patients were informed and instructed b y one researcher about normal jaw function. The information and instructions were repeate d at all evaluation times (at 0, 3, 6, 12, 26 and 52 weeks). In addition to the information and instructions, the patients randomized to the PT group received nine PT sessions scheduled over six weeks. The PT sessions started with repeating the information and instructions, fol lowed by stretch and relaxation techniques for the painful muscles. For the patients with loc ked jaw, rotation exercises and mobilization techniques were applied subsequent to the str etch and relaxation treatments. All these techniques were demonstrated to the patient to be included in a home exercise program. They were encouraged to do this home program for at le ast six weeks after finalising the PT sessions. In both studies, all pain variables decrease d and all function variables increased significantly over time, both for the treatment and the control group. However, since we did not find a difference between the treatment and th e control groups, theeffect of PT has to be considered non-specific.