Comparative Study of Repositioning Splint Therapy and Passive Manual Range of Motion Techniques for Anterior Displaced Temporomandibular Discs with Unstable Excursive Reduction

Summary

Background

The purpose of this study was to compare two treatment methods: Mobilisation with active exercises, and soft repositioning splinting, as treatment protocols for relief of symptoms secondary to anterior displaced temporo- mandibular disc (ADTMD) syndrome.

Methods

Thirty-six individuals between 19 and 43 years old with ADTMD participated in this study. Eighteen patients were chosen randomly to receive four weeks of treatment with a soft repositioning splint, and the other 18 received passive mobilisation and active exercises. All subjects were assessed for active range of motion for maximum mouth opening and pain levels, which were measured according to the pain-physiopathology instrument, before and after treatment.

Results

The manual mobilisation with exercises group demonstrated a significant decrease in total pain level (p < 0.05), and improved mouth opening (p < 0.05). The soft repositioning splint group failed to show significant change in either variable.

Conclusion

This study suggests that manual mobilisation and active exercises are more effective for treatment of pain and range of motion deficits associated with ADTMD, than soft repositioning splint therapy. These improvements do not necessarily mean that the disorder is cured.

Introduction

Confusion in the diagnosis and treatment of temporomandibular dysfunction syndrome (TMDS) has been documented in the last 65 years by many investigators (Costen, 1934; Ireland, 1952; Hargreaves, 1986; Baratz et al, 1996; Sessle, 1990; Dworkin et al., 1992, Dworkin, 1995; Chin et al, 1996). During this time, physicians and therapists have seen many different solutions to the problem and have witnessed various levels of success and failure. This syndrome remains a con-troversial topic in most aspects. There is no consensus among researchers about its etiology, diagnosis or clinical man-agement (NIH, 1996). Patients with TMDS may present with various symptoms such as tinnitus (Richard et al, 1992), headaches, earaches, subjective loss of hearing and equilibrium, neck and shoulder pain (Wijer et al, 1996), inconsistent tooth pain, numbness and tingling in the palate and throat, sinus symptoms, congestion and depression (Gatchel et al, 1996), in addition to limitation of jaw movement and temporal or spatial pain, joint sounds such as clicking, grinding and popping in the jaw area (Sutton et al, 1992; Mopsik, 1996; Nagahara et al, 1999).

The temporomandibular joint (TMJ) is of interest to physiotherapists owing to its possible movement dysfunction and the large variety of related problems such as subluxation and dislocation (Anderson, 1994). However, treating such malfunction occasionally requires choosing from several different treatment procedures such as electrotherapy – ultrasound, shortwave diathermy, etc (Taylor and Newton, 1988) – and exercises, with patient education as well as dental, pharmacological (Denucci et al, 1996) or psychological interventions (Gatchel et al, 1996).

The Academy of Prosthodontics (1999) has given one of the most common definitions of TMDS:

• Abnormal, incomplete or impaired function of the TMJ.

• A collection of symptoms frequently observed in various conditions.

These conditions include internal derangement, which involves a structural alteration in the articular components and anterior displaced temporomand-ibular discs with unstable excursive reduction (Moriya et al, 1996; Anderson et al, 1985; Schwartz and Kendrick, 1984). Executing smooth translatory movement while simultaneously preserving normal function of the TMJ requires adequate stability in closed pack position, resting position, biting or even full opening.

All intra- and extra-articular anatomical components of the TMJ are essential for proper and continuous non-compromised biomechanical function. Flat plane occlusal repositioning-splints have traditionally been the treatment for the neuromuscular component of masticatory disorders to reduce poor oral habits, particularly those due to occlusal faults or parafunctions like bruxism (Kampe et al, 1997). Occlusal position is ‘the relationship of mandible and maxillae when the jaw is closed and the teeth are in contact’ and bruxism is defined as follows by the Academy of Prosthodontics (1999):

• Parafunctional grinding of teeth.

• An oral habit consisting of involuntary thythmic or spasmodic non-functional movements which may lead to occlusal trauma.

When the painful chewing muscles (temporalis, masseter and pterygoid medial) relax, the muscular-induced restriction of mouth opening can be improved (Hamada et al, 1982; Mejias and Mehta, 1982; Droukas et al, 1985). Dentists frequently prescribe occlusal repositioning splints to treat patients who grind their teeth (bruxers), and those with TMDS. An occlusal splint is ‘any removable artificial occlusal surface used for diagnosis and therapy affecting the relationship of the mandible to the maxillae’ (Academy of Prosthodontics, 1999).

In the USA, dentists or orthodontists make different kinds of splints (soft or acrylic) for approximately two million people each year (Pierce et al, 1995). The upper-anterior occlusal repositioning splint is used to prevent occlusion of the posterior teeth and thereby prevent forms of parafunctional activities (Magnusson and Enbom, 1984). The splint is a flat platform, non-guiding or locking the mandible into either anterior or post-ruded position (Okenson et al, 1983). The soft splint is used in the treatment of TMJ syndromes in an effort to correct mal-occlusion, which was most likely caused by varying abnormalities of dental occlusal structures and malfunction of masticatory muscles (Israel et al, 1999). Thus the splint allows only minimal separation of the occlusal surfaces (approximately 2 mm). Manual mobi-lisation results in inhibiting the excitability of the motor neurone pool and hence decreases pain (Vujnorich, 1995).

Joint mobilisations can be defined as those accessory movements performed on a joint that ease pain or affect the involved structures to maintain their well-being. Many investigators have studied the general effects of joint mobilisation (Kaltenborn, 1974; Rocabado, 1983; Maitland, 1977; Keating et al, 1993). Manual joint mobilisations with active exercises help maintain normal and painless joint function. Passive and active movements can restore the lubrication efficiency between collagen fibres, stimulating glycoaminoglycan synthesis to allow movements in the periarticular structures. This led to the hypothesis that manual mobilisation with active exercises would be more beneficial than a soft occlusal repositioning splint to reduce pain in the TMJ, and to increase range of movement in mouth opening. The present study was designed to compare the results of two treatment protocols for the manage-ment of ADTMD syndrome.