Tinnitus is one of the most prevalent symptoms that causes more disability in patients with temporomandibular disorder (TMD). The present study postulates a possible link between temporomandibular joint (TMJ) and inner ear based on their anatomical, biomechanical and physiological relationship, proposing a physiotherapy treatment for the temporomandibular joint to improve tinnitus. The aim of the study is to evaluate the effectiveness of adding specific manual therapy to a multimodal physiotherapy treatment in patients with tinnitus and temporomandibular disorder.

1. - INTRODUCTION

   Tinnitus is one of the most prevalent symptoms that causes more disability in patients with temporomandibular disorder (TMD).

   According to various studies, the incidence varies between 19-69%, with a 2:1 ratio between women and men, being higher in Western industrialized countries. Frequent conjunction between TMJ problems and tinnitus has led to propose the existence of a link between these two clinical entities. However, the mechanism linking TMD and this otologic symptom is unknown.

   The present study postulates an association based on the anatomical relationship between the TMJ and the inner ear. The ligaments of the inner ear bones are close to TMJ ligaments so the movements of the mandibular condyle may influence on them. The discomallear ligaments (DML) and the anterior mallear ligament (AML) can be considered as intrinsic ligaments of the TMJ.

   TMJ blood supply depends on the tympanic and auricular arteries, and in its innervations are involved nerve branches of the masseter, lateral and temporal/ internal pterygoid, key muscles for the condylar movements (open and close the mouth and lateral movements).

   The hypothesis supporting the link between the TMJ and the tinnitus is that the forced movements of the mandibular condyle produce a ligaments stretching and muscles tension, being the cause of otologic problems such as tinnitus.

   Tinnitus is defined as the perception of a sound that does not exist in the environment. It is often described as "a buzz, a beep, a noise". Most conservative treatments for tinnitus have focused on pharmacological treatments (particularly antidepressants), cognitive-behavioral treatments, medical low strength laser therapies, acupuncture, cranial magnetic stimulation, music therapy and environmental sounds reduction technologies. However, there is controversial evidence on the effectiveness of these techniques given the heterogeneity of protocols and of the response variables.

   Is understood as TMJ pathology, those organic or functional nosological entities affecting the craneomandibular system relationship. They encompass a large number of disorders, not only traumatic, neoplastic, autoimmune or infectious, but also those deriving from dysfunctional alteration of its internal structure, both muscle and joints.

   TMJ disorders with a myofascial or joint dysfunction origin are those whose origin is in myofascial muscle disorders or in joint by mechanical causes. Myofascial trigger points pain, described by Travell and Simons, corresponds to a noninflammatory regional muscle pathology that can occur in any striated muscle of the body. Its main feature is the presence of a hypersensitive area called trigger point, which is present in a palpable taut band of muscle tissue and has the ability to refer pain to distant areas. Joint dysfunction is defined as one in which occurs an abnormal relationship between the joint disk and the condyle, the fossa and the TMJ eminence.

   Many treatments have been applied to the TMJ with varying degrees of evidence: the prevention of bad habits and parafunctions; contract/relax muscles and mental exercises; heat / cold in pain or contracture areas; physiotherapy; psychotherapy; biofeedback techniques with self-relaxation procedures; resting splints, muscle discharge or recapture; transcutaneous electrical nerve stimulation and ultrasound and drug treatment: NSAIDs, analgesics, anxiolytics, hypnotics, muscle relaxants and antidepressants.

   In most cases, the physiotherapy in patients with TMD is focused on myofascial treatment and massage and, at present, in manual therapy (for pain control and improving joint movement). All of this, usually combined with splints or bite plates (for pain control, bruxism and improving occlusion), although there is little evidence supporting their use.

   In relation to myofascial therapy, massage applied on the masticatory muscles, protocols of manual therapy on TMJ, as well as mobilization and manipulation techniques of the upper cervical spine, there is a wide and proven evidence of the improvement occurring in pain, mouth maximum mouth opening and in pressure pain threshold in patients with TMD; although systematic reviews on all manual therapy techniques present a controversial evidence, given the heterogeneity of the studies.

   In the literature review made, it has not been found any paper issuing a proposal or treatment protocol of the TMJ presenting among its main objectives the control of the intensity of TMJ pain and the decrease of disability that tinnitus produces.

   Only one found study proposes a treatment to reduce the intensity of TMJ pain and to improve the disability that tinnitus produces by using a bite splint, without performing a manual intervention therapy and exercises.

   The purpose of the present study is to raise a proposal of treatment with manual therapy and exercise aiming to reduce the disability caused by tinnitus and the intensity of pain and disability caused by the TMD.

2. - JUSTIFICATION

   Tinnitus is one of the most prevalent symptoms that causes more disability in patients with temporomandibular dysfunction (TMD).

   The frequency with which concur the problems of the temporomandibular joint (TMJ) and tinnitus, has led to propose the existence of an association between these two clinical entities.

   The present study postulates the possible link developing an anatomical-pathophysiological hypothesis based on the relationship between TMJ and inner ear, proposing a treatment applied to temporomandibular joint for improving TMJ pain and tinnitus.

3. - HYPOTHESIS AND OBJECTIVES

Hypothesis:

The addition of specific manual therapy techniques (TM) within a multimodal physiotherapy treatment is more effective in improving TMJ pain and disability that causes tinnitus that the isolated application of multimodal treatment.

Objectives:

General:

Evaluate the effectiveness of adding specific manual therapy to a multimodal physical therapy in patients with tinnitus and TMD with a myofascial origin or joint dysfunction.

Specific:

1. Evaluate the effectiveness of adding specific manual therapy to a multimodal physical therapy in patients with tinnitus and TMD in reducing pain intensity and disability caused by TMD.
2. Evaluate the effectiveness of adding specific manual therapy to a multimodal physical therapy in patients with tinnitus and TMD in reducing the intensity of tinnitus and disability caused by tinnitus.
3. Evaluate the effectiveness of adding specific manual therapy to a multimodal physical therapy in patients with tinnitus and TMD in increasing the range of motion of the TMJ.
4. Evaluate the effectiveness of adding specific manual therapy to a multimodal physical therapy in patients with tinnitus and TMD in the painful rise by pressuring the masseter, temporal and lateral pterygoid muscles.
5. Evaluate the effectiveness of adding specific manual therapy to a multimodal physical therapy in patients with tinnitus and TMD in the quality of life, level of anxiety / depression and health.

4. METHODOLOGY

Type of study: randomized and controlled pilot study, multicenter, blinded randomization, patient assessment and data analysis. Treatment characteristics themselves prevent their blinded application.

Location: 3 private consultation rooms of specialized physiotherapy in TMD. Study subjects: 56 patients with temporomandibular dysfunction and tinnitus.

The patient will receive six treatment sessions, two sessions in the first week and a weekly session to complete the intervention. The total duration of the intervention shall be one month. Before starting the study, all patients will be asked to sign an informed consent.

The statistical analysis will be performed using SPSS 22.0 program (IBM statistical software). The average and the standard deviation of quantitative variables will be calculated for the descriptive analysis of the sample if normally distributed.

For the comparative analysis, developed according to the intention to treat:

1. An ANOVA for repeated measure test should be carry out to evaluate the interaction between levels of inter - subject factor (treatment) and the intra- subject (main variables response in time) to be interpreted in case it is significant.
2. To confirm whether this interaction effect is significant, pairwise comparisons will be made of the inter-subjects factor levels (treatment) for each level of main response variables over time using the Bonferroni method.

Limitations of the study - Masking: The nature of the applied treatments prevents masking therapists and patients. This limitation is inherent to the type of treatment evaluated and common with other forms of treatment with similar characteristics, in which therapist should inevitably know the type of treatment that is applied. However, this limitation does not prevent the controlled clinical trials carried out on these technologies from being of higher methodological quality. Thus, in this study, randomization of patients will be blinded, allocation of the random sequence, the assessment of patient evolution and analysis of results.

Inclusion Criteria:

• ≥ 18 and ≤ 65 years old.
• Suffering from tinnitus and temporomandibular dysfunction with a myofascial or joint dysfunction origin: diagnosis of tinnitus attributed to TMD
• In a subacute and chronic phase.

Exclusion Criteria:

• Non signature of the informed consent.
• Patients with a diagnosis of ENT and / or neurological problems from which could arise tinnitus and / or the temporomandibular pain.
• Inability to read, understand and complete questionnaires, read and understand a brochure, or understand and follow verbal commands (e.g. Illiteracy, dementia or blindness).
• Having received physiotherapy in the last 12 months.