Pumping injection of sodium hyaluronate for patients with non-reducing disc displacement of the temporomandibular joint: two year follow-up

Effects of low and high molecular weight hyaluronic acid on the osteoarthritic temporomandibular joint in rabbit

OBJECTIVE

To compare the effect between intra-articular infiltration of low molecular weight (LMW-HA) and high molecular weight hyaluronic acid (HMW-HA) on the histopathological characteristics of the cartilage and disc of the temporomandibular joint (TMJ) osteoarthritis (OA) induced in rabbits.

MATERIAL AND METHODS

An experimental study was conducted on 38 rabbit TMJs. The effect of different hyaluronic acids was compared at 30 and 135 days. Histopathological analysis was performed. Cartilage damage was assessed with the OARSI scale.

RESULTS

The severity of the induced OA according to OARSI was 3.4 degrees in the mandibular condyle (MC) and 3.2 in the mandibular fossa (MF); the articular disc (AD) presented disorganization of the collagen fibers, with randomly arranged hypertrophic chondrocytes. At 30 days, untreated TMJs worsened. TMJ treated with LMW-HA reduced its severity to 1.5 degrees in MC and 1.6 in MF, the AD presented histological aspects within normal limits. TMJ treated with HMW-HA presented 2.4 degrees in MC and 2.2 in MF, the AD maintained characteristics similar to the group with OA. At 135 days, all groups worsened.

CONCLUSION

Exogenous HA is effective in the management of TMJ-OA induced in rabbits, showing cartilage and articular disc repair at 30 days. The LMW-HA group had better effects on joint tissue than HMW-HA 30 days after treatment. However, at 135 days, both groups presented regression of joint tissue repair.

CLINICAL RELEVANCE

HA is effective in the anti-arthritic treatment of TMJ-OA induced in rabbits; LMW-HA shows better results in cartilage and articular disc repair than HMW-HA.

The Effectiveness of Hyaluronic Acid in Controlling Pain, Edema, and Trismus After Extraction of Third Molars: Systematic Review and Meta-Analysis

This study aimed to evaluate the clinical evidence of hyaluronic acid (HA) in minimizing inflammatory parameters such as pain, edema, and trismus after extraction of third molar (3M). An electronic search was conducted in 4 databases. The eligibility criteria included clinical trials that used HA compared with placebo or no treatment after 3M surgeries. The search strategy resulted in 752 references, of which 5 studies were included comprising 271 patients. Regarding the risk of bias analysis, most criteria were rated as low or unclear risk of bias. All the evaluated studies were classified as low risk of bias in the selective reporting criteria. The final quantitative analysis of the variables showed that the use of HA resulted in a greater reduction of pain levels on the third (mean difference = -0.68; 95% confidence interval, -1.20 to -0.17) and seventh (mean difference = -0.36; 95% confidence interval, -0.64 to -0.09) postoperative days. There are no differences between the analyzed groups in relation to trismus. It was not possible to conduct meta-analysis for the edema variable because of the heterogeneity of the methods of measurement. The results suggest that HA seems to provide a lower average pain on the third and seventh postoperative days and has no influence on postoperative trismus after extraction of 3Ms; however, more research with stronger methodology is needed to determine its efficacy.

Arthrocentesis and Sodium Hyaluronate Infiltration in Temporomandibular Disorders Treatment. Clinical and MRI Evaluation

Arthrocentesis in temporomandibular joint disorders can be associated with the intra-articular infiltration of various drugs with the objective of increase treatment efficacy. The aim of this study was to evaluate the clinical indexes variation in patients affected by temporomandibular joint disorders treated with arthrocentesis and sodium hyaluronate (SH) injections. A total of 28 patients suffering from temporomandibular joint disorders underwent one cycle of five arthrocentesis and infiltrations of sodium hyaluronate. Spontaneous mouth opening improved from 36.3 ± 7.5 mm to 45.1 ± 1.9 mm at six months follow-up. A significant reduction in the pain at rest and during mastication mean values emerged at follow-up (p < 0.0001). The mean masticatory efficiency, evaluated through a visual analogic scale, showed improvement at the follow-up period, highlighted by the increase of mean value from a baseline of 3.1 ± 1.2 to a mean value of 8.5 ± 1.2 (p < 0.0001). The mean severity of the joint damage at baseline time was 2.4 ± 0.9 and decreased to 0.4 ± 0.3 at the end of the follow-up period. The decrease in values is confirmed by statistical test (p < 0.05). Our data show how arthrocentesis integrated with sodium hyaluronate infiltrations performed under local anesthesia is a valid method of treating temporomandibular joint disorders.

The effect of hyaluronic acid addition on the properties of smoked homogenised sausages

BACKGROUND

This research studied the possibility of using hyaluronic acid (HA) as a food additive for meat emulsions to create a novel functional food with improved rheological and water binding properties. Sausages with 200 and 500 g kg^-1 water addition were supplemented with 0, 0.01, 0.05 and 0.1 g kg^-1 of HA and stored for 14 days in vacuum. Rheology, texture, weight losses, proximate composition and microbiological analyses were performed together with the sensory evaluation of produced sausages.

RESULTS

Surprisingly, the results show that the addition of 0.05 and 0.1 g kg^-1 HA reduced yield and the stability of meat emulsion by causing water outflow from the product and decreased the sensory scores of the produced sausages. The sausage with 500 g kg^-1 water and 0.01 g kg^-1 HA addition was the only economically viable option for introducing the product on the market.

CONCLUSION

HA has a potential of being a perfect functional food additive for meat industry, although further research regarding processing conditions should be performed. © 2016 Society of Chemical Industry.

Chitosan-Based Thermosensitive Hydrogel for Controlled Drug Delivery to the Temporomandibular Joint

Intra-articular injections of hyaluronic acid (HA) and corticosteroids have been extensively used in treating temporomandibular disorders. However, rapid clearance from the site of injection is a major concern that is commonly managed by frequent dosing, which is not without complications. This study aimed to determine the suitability of thermosensitive chitosan-based hydrogels for intra-articular controlled release of drugs in the rabbit temporomandibular joint (TMJ). A series of hydrogels were prepared using different chitosan (Ch) to β-glycerophosphate (β-GP) ratios. The gelation time, swelling ratio, the shape, and surface morphology of the prepared gels were investigated to select the formulation with optimum characteristics. The left TMJ in 13 adult male New Zealand white rabbits was injected with 0.2 mL of Chitosan/β-glycerophosphate/HA while the right TMJ was injected with 0.2 mL of control solution of HA. Hyaluronic acid concentrations in experimental and control groups were measured using Hyaluronan Quantikine Enzyme-Linked Immunosorbent Assay Kit. In vitro characterization showed that both the Ch:β-GP ratio and incorporation of HA had a significant effect on gelation time, degree of swelling, and surface morphology of the hydrogels. No morphological changes were observed in the joints in both groups. The mean concentration of HA in the experimental joints after 7 days (1339.79 ± 244.98 μg/g) was significantly higher than that in the control (474.52 ± 79.36 μg/g). In conclusion, the chitosan-based thermosensitive hydrogel can be considered as a promising controlled drug release system to the TMJ in a rabbit model that would potentially overcome many of the current limitations of intra-articular formulations.

Differences Regarding Branded HA in Italy, Part 2: Data from Clinical Studies on Knee, Hip, Shoulder, Ankle, Temporomandibular Joint, Vertebral Facets, and Carpometacarpal Joint

OBJECTIVES

The aim of the current study is to collect scientific data on all branded hyaluronic acid (HA) products in Italy that are in use for intra-articular (IA) injection in osteoarthritis (OA) compared with that reported in the leaflet.

METHODS

An extensive literature research was performed for all articles reporting data on the IA use of HA in OA. Selected studies were taken into consideration only if they are related to products based on HAs that are currently marketed in Italy with the specific joint indication for IA use in patients affected by OA.

RESULTS

Sixty-two HA products are marketed in Italy: 30 products are indicated for the knee but only 8 were proved with some efficacy; 9 products were effective for the hip but only 6 had hip indication; 7 products proved to be effective for the shoulder but only 3 had the indication; 5 products proved effective for the ankle but only one had the indication; 6 products were effective for the temporomandibular joint but only 2 had the indication; only 2 proved effective for vertebral facet joints but only 1 had the indication; and 5 products proved effective for the carpometacarpal joint but only 2 had the indication.

CONCLUSIONS

There are only a few products with some evidences, while the majority of products remain without proof. Clinicians and regulators should request postmarketing studies from pharmaceuticals to corroborate with that reported in the leaflet and to gather more data, allowing the clinicians to choose the adequate product for the patient.

A comparative study on the impact of intra-articular injections of hyaluronic acid, tenoxicam and betametazon on the relief of temporomandibular joint disorder complaints

OBJECTIVE

The aim of this study was to compare the efficacy of intra-articular injections of three different agents with well known anti-inflammatory properties.

MATERIALS AND METHOD

Between April 2010 and January 2013 a total of 100 patients who were diagnosed as temporomandibular joint disorder in the Department of Otolaryngology at Bozok University School of Medicine were prospectively studied. Patients with symptoms of jaw pain, limited or painful jaw movement, clicking or grating within the joint, were evaluated with temporomandibular CT to investigate the presence of cartilage or capsule degeneration. In the study group there were 55 female and 45 male patients who were non-responders to conventional anti-inflammatory treatment for TMJ complaints. The patients were randomly divided into four groups consisting of a control group and three different groups who underwent intra-articular injection of one given anti-inflammatory agent for each group. We injected saline solution to intra-articular space in the control group. Of three anti-inflammatory agents including hyaluronic acid (HA, Hyalgan intra-articular injection, Sodium hyaluronate 10 mg/ml, 2 ml injection syringe, Bilim Pharmaceutical Company, Istanbul, Turkey); betamethasone (CS, Diprospan flacon, 7.0 mg betamethasone/1 ml, Schering-Plough Pharmaceutical Company, Istanbul, Turkey) and; tenoxicam (TX, Tilcotil flacon, 20 mg tenoxicam/ml, Roche Pharmaceutical Company, Istanbul, Turkey) were administered intra-articularly under, ultrasonographic guidance. Following the completion of injections the, changes in subjective symptoms were compared with visual analogue scales, (VAS) scores at 1st and 6th weeks' follow-up visits between four groups.

RESULTS

The HA group did significantly better pain relief scores compared to the, other groups at 1st and 6th weeks (p < 0.05). TX and CS groups' pain scores were better than control group values (p < 0.05, for both agents). The pain relief effect of TX was noted to decrease significantly between the 1st and 6th week (p < 0.05) (Fig. 1). We did not observe the same pattern in HA, CS and control (saline) groups between 1st and 6th week (p > 0.05).

CONCLUSION

We found that HA produced better pain relief scores when compared to the other anti-inflammatory agents studied. The main disadvantage of HA is its relatively higher cost. Additionally it does not have a reimbursement status by state or private health insurance systems in Turkey. Despite the lower VAS scores, intra-articular TX and CS may be assessed as more economic alternatives to intra-articular HA injections.

Evaluation of efficacy of arthrocentesis (with normal saline) with or without sodium hyaluronate in treatment of internal derangement of TMJ - A prospective randomized study in 20 patients

PURPOSE

To compare the outcome of arthrocentesis alone and arthrocentesis with sodium hyaluronate in internal derangement of TMJ.

MATERIALS AND METHODS

20 patients of disc displacement with reduction of TMJ were randomized into 2 experimental groups. Control group of patients received arthrocentesis alone and study group of patients received arthrocentesis with sodium hyaluronate. Patients TMJ status and clinical symptoms were evaluated for 6 months follow up. The clinical parameter recorded were maximal mouth opening (MMO), lateral excursions (right and left side), protrusive movement, joint noises, and pain (at rest, at function).

RESULTS

When 2 groups are compared there was no statistically significant difference in terms of inter-incisal opening, lateral excursion, protrusive movement, joint noises and pain however the group with sodium hyaluronidase has shown better results than the control group.

CONCLUSION

Both study and control group found to be statistically insignificant but patient who were in the group of arthrocentesis with admission of sodium hyaluronidase had better results.

Preliminary evaluation of histological changes found in a mechanical arthropatic temporomandibular joint (TMJ) exposed to an intra-articular Hyaluronic acid (HA) injection, in a rat model

OBJECTIVE

This study investigates the histological effects of Hyaluronic acid injections in the treatment of induced temporomandibular joint (TMJ) osteoarthritis in rats.

STUDY DESIGN

Twenty-four male Wister rats were subjected to induced mechanical osteoarthritis by manual hypermobility for 10 successive days. Animals were then divided into two groups; group I (control) and group II (experimental). Ten days after the induction of hypermobility, the right TMJ of the experimental animals was injected with a dose of 0.12 mg HA intra-articularly and 0.12 mg saline was injected into the left joint; while animals in the control group were left without any treatment. Two rats from group I were killed at one, two and six weeks; while 6 animals from group II were killed at one, two and four weeks post injection.

RESULTS

The disk of the right joints in the experimental animals was of normal thickness and there was an increase in the thickness of the fibrocartilagenous layer. In the left joint; ulcerative changes in the disk were evident where the fibres were not well oriented and scalloped areas in the temporal bone area were present denoting osteoclastic activity.

CONCLUSIONS

Repeated intra-articular TMJ injection of Hyaluronic acid appears to be a safe and effective way of inhibiting the progression of osteoarthritic changes in the joint through development of articular cartilage and reducing fibrous tissue proliferation.

Short-term effects of arthrocentesis plus viscosupplementation in the management of signs and symptoms of painful TMJ disc displacement with reduction. A pilot study

AIM

To provide data on the short-term effect of a cycle of five weekly arthrocenteses plus hyaluronic acid injections in the management of signs and symptoms of painful disc displacements.

METHODS

Thirty-one consecutive patients (25 females, six males; mean age 42.4) with a combined diagnosis of disc displacement with reduction and arthralgia according to the Research Diagnostic Criteria for Temporomandibular Disorders underwent a cycle of five arthrocenteses with injections (one per week) of 1 ml hyaluronic acid. A number of subjective and objective clinical parameters were assessed at the time of the diagnosis (baseline), at each appointment during the treatment, at the end of the treatment, and three follow-up appointments (1 week, 1 month, and 3 months).

RESULTS

At the end of the treatment period, marked improvements with respect to baseline values were recorded in all the outcomes variables, and they were maintained over the 3-month follow-up span. Significant changes were shown in subjective outcome variables, viz., masticatory efficiency, maximum pain levels, functional limitation, perceived efficacy, and objective clinical parameters, viz., jaw range of motion on different movements. Tolerability of treatment was acceptable since the first intervention and was moderately improved over time.

CONCLUSIONS

A cycle of five weekly hyaluronic acid injections performed immediately following arthrocentesis is effective to improve signs and symptoms in patients with painful temporomandibular joint disc displacement with reduction and to maintain them over a 3-month follow-up.

Emerging intra-articular drug delivery systems for the temporomandibular joint

Temporomandibular joint (TMJ) disorders are a heterogeneous group of diseases that cause progressive joint degeneration leading to chronic pain and reduced quality of life. Both effective pain reduction and restoration of TMJ function remain unmet challenges. Intra-articular injections of corticosteroids and hyaluronic acid are currently used to treat chronic pain, but these methods require multiple injections that increase the risk of iatrogenic joint damage and other complications. The small and emerging field of TMJ tissue engineering aims to reduce pain and disability through novel strategies that induce joint tissue regeneration. Development of methods for sustained, intra-articular release of growth factors and other pro-regenerative signals will be critical for the success of TMJ tissue engineering strategies. This review discusses methods of intra-articular drug delivery to the TMJ, as well as emerging injectable controlled release systems with potential to improve TMJ drug delivery, to encourage further research in the development of sustained release systems for both long-term pain management and to enhance tissue engineering strategies for TMJ regeneration.

Arthrocentesis of the temporomandibular joint: a proposal for a single-needle technique

Arthrocentesis is a method of flushing out the temporomandibular joint (TMJ) that is currently performed by providing a double access to the joint space. Several studies have shown that arthrocentesis of the upper compartment of the TMJ may be a highly effective method to restore normal maximal mouth opening and functioning. Nonetheless, the classical 2-needle technique has some limits, such as the low tolerability and difficulty in performing it in the presence of intra-articular adherences. The adoption of a single-needle for both fluid injection and aspiration might have some advantages with respect to the traditional 2-needle approach in terms of time of execution, tolerability, and retention of medication. These potential advantages have to be assessed with future randomized and controlled clinical trials.

Evaluation of mouth opening exercise after pumping of the temporomandibular joint in patients with nonreducing disc displacement

PURPOSE

The purpose of this study was to investigate whether an additional mouth opening exercise contributes to better outcome in patients with nonreducing disc displacement who underwent pumping of the temporomandibular joint (TMJ).

PATIENTS AND METHODS

Twenty-three female patients with nonreducing disc displacement of the TMJ underwent pumping of the TMJ and did mouth opening exercise after this treatment (rehabilitation group). Thirty-six female patients with nonreducing disc displacement of the TMJ underwent pumping of the TMJ, but did not do mouth opening exercise (non-rehabilitation group). Patients' signs and symptoms were examined monthly. Clinical evaluation was conducted according to the criteria presented by the 1995 American Association of Oral and Maxillofacial Surgeons. Outcomes were compared between the 2 groups at 12-month follow-up. Chi-square tests were used to assess the difference in good resolution rate between the 2 groups. When significant difference was not found, a non-inferiority test (Delta = 0.1) was used. Level of significance was set on P values less than .05.

RESULTS

In both groups, clinical signs and symptoms improved. There was a good resolution rate of 60.9% in the rehabilitation group and 75% in the non-rehabilitation group. No significant difference was observed between the 2 groups. The non-inferiority test showed that the good resolution rate of the non-rehabilitation group was significantly equivalent or more to that of the rehabilitation group (P < .05).

CONCLUSIONS

Mouth opening exercise did not seem to contribute to better outcomes in patients with nonreducing disc displacement who underwent pumping of the TMJ.

A one-year case series of arthrocentesis with hyaluronic acid injections for temporomandibular joint osteoarthritis

OBJECTIVE

The present study presents a case series on the efficacy of arthrocentesis with hyaluronic acid injections for the treatment of temporomandibular joint osteoarthritis by providing patient evaluations at a one-year follow-up.

STUDY DESIGN

Twenty-five patients with a diagnosis of osteoarthritis according to the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD axis I group IIIb) underwent a cycle of 5 arthrocenteses with injections (1 per week) of 1 mL hyaluronic acid. A number of clinical parameters (pain at rest and mastication, masticatory efficiency, maximum nonassisted and assisted mouth openings, functional limitation, subjective efficacy, and tolerability of the treatment) were assessed by the same blinded operator at the time of the diagnosis (baseline), at each appointment during the treatment, and at 1-week, 1-month, 3-month, 6-month, and 1-year follow-up appointments.

RESULTS

Descriptive analysis showed improvements which were maintained over time for all the study parameters. Permutation tests evidenced the significance of changes which occurred in many clinical parameters within the first 2 injections. Differences with baseline levels remained significant at the end of the follow-up period, particularly for the masticatory efficiency and pain at mastication (minimum and maximum) parameters.

CONCLUSIONS

Data from the present investigation support findings from studies on other joints, which show the efficacy of serial injections of hyaluronic acid after arthrocentesis to reduce symptoms of osteoarthritis and to maintain improvements over time.

Efficacy and safety of intraarticular hyaluronic acid in the treatment of hip osteoarthritis: a systematic review

OBJECTIVE

This study sought to use a systematic review to ascertain the efficacy and safety of hyaluronic acid (HA) in the treatment of hip osteoarthritis (OA).

DESIGN

A protocolized search was made of a number of electronic databases, including Medline, EMBASE, Cochrane Library and Health Technology Assessment (HTA) among others. Two independent reviewers applied a series of inclusion and exclusion criteria to the studies located in the search, and selected only those that included more than 20 patients; had a follow-up period of more than 1 week; and exclusively assessed the efficacy and/or effectiveness of HA in patients with confirmed hip OA.

RESULTS

A total of eight studies, comprising clinical trials and one review, met the inclusion criteria, and had study populations ranging from 22 to 104 patients. Only two of the trials were controlled: one compared two HAs of different molecular weights; and the other compared HA with corticoids and a placebo. Relief of pain was estimated to be around 40-50% by most studies, though the duration of this post-treatment effect was not known.

CONCLUSIONS

Based on available evidence, HA treatment should only be used under careful supervision by the clinician and just in those cases where other treatments have failed in hip OA. There are methodologic limitations displayed in the literature, which were mainly the absence of a control group in most of the studies, overly short follow-up periods, and different ways of measuring outcomes.

Image-guided minimally invasive surgical access to the temporomandibular joint: A preliminary report

PURPOSE

To establish a protocol for image-guided minimally invasive surgical access to the temporomandibular joint (TMJ).

MATERIALS AND METHODS

This study involved 2 patients with TMJ pain and mandibular motion dysfunction. Axial magnetic resonance imaging (MRI) of the TMJ was obtained and loaded into an intra-operative navigation system to guide joint space injection. With a navigated syringe, 1 mL synvisc Hylan G-F 20 was directly injected into the superior and inferior joint spaces under navigation guidance.

RESULTS

With the assistance of an intraoperative navigational system, the TMJ MRI images were visualized in 3 dimensions and enabled guiding a needle into the superior and inferior joint spaces for therapeutic injection. The treatment outcome for both patients was satisfactory with improvement in pain score and mandibular motion.

CONCLUSIONS

A protocol for image-guided minimally invasive surgical access to the TMJ was established. This could provide the technical basis for evaluation of accurate joint space intervention as a form of treatment of appropriate TMJ disorders.

Short-term therapeutic outcome of intra-articular high molecular weight hyaluronic acid injection for nonreducing disc displacement of the temporomandibular joint

In a patient with temporomandibular disorder who does not respond to conservative treatment, treatment with intra-articular injection of high molecular weight sodium hyaluronate can be suggested. In our study, 27 patients with nonreduced disc displacement were diagnosed clinically and confirmed by magnetic resonance imaging. The age range was from 21 to 63 years old, with a mean of 39.3 years. Two cycles of injection of high molecular weight sodium hyaluronate was performed on alternative weeks. Pain intensity was measured by the visual analog scale. Maximal mouth opening, clicking joint noise, and lateral movement were measured before and after injection for more than 6 months. Reduction of pain intensity and improvement in the maximum mouth opening parameter was statistically significant. In conclusion, this intra-articular injection using high molecular weight sodium hyaluronate looks very positive for patients affected by nonreduced disc displacement and is encouraged to be used as a primary treatment of temporomandibular joint dysfunction.

Intraarticular hyaluronic acid versus glucocorticoid injections for nonradicular pain in the lumbar spine

PURPOSE

To investigate the efficacy and safety of intraarticular sodium hyaluronate (SH) compared with intraarticular glucocorticoids (triamcinolone acetonide; TA) in the treatment of chronic nonradicular lumbar pain.

MATERIALS AND METHODS

Sixty patients were included in this randomized, controlled, blind-observer clinical study and randomly assigned to two groups to receive 10 mg SH or 10 mg TA per facet joint. The facet joints on both sides at levels S1-L5, L5-L4, and L4-L3 were treated once per week under computed tomographic guidance. The study visits were timed to permit assessment of the immediate effect as well as possible carryover effects at 3 and 6 months after completion of treatment. Changes in pain were assessed with a visual analog scale (VAS) and changes in function and quality of life were assessed by the Roland Morris Questionnaire (RMQ), the Oswestry Disability Questionnaire (ODQ), the Low Back Outcome Score (LBOS), and the Short Form 36 (SF-36) questionnaire.

RESULTS

Patients reported lasting pain relief, better function, and improved quality of life with both treatments. Mann-Whitney analyses of the patient questionnaires (RMQ, ODQ, and LBOS) very consistently showed that SH is not inferior to TA. In addition, the efficacy of SH was largely comparable with that of TA on the VAS and SF-36. No adverse effects were reported after administration of the test products. The intraarticular treatment of facet joints (levels S1-L5, L5-L4, and L4-L3) with SH in patients with chronic nonradicular pain in the lumbar spine resulted in a marked reduction in pain with improved function and better quality of life, which was at least equal to the effect of a course of TA injections. SH-treated patients showed greater benefits in the long term.

CONCLUSION

Intraarticular SH is a very promising new option for the treatment of patients with chronic nonradicular lumbar symptoms.

Analysis of kinesiograph recordings and masticatory efficiency after treatment of non-reducing disk displacement of the temporomandibular joint

The purpose of this study was to clarify the kinesiographs of chewing movement and masticatory efficiency before and after treatment in patients with non-reducing disk displacement of the temporomandibular joint (TMJ). Twenty patients who were diagnosed with unilateral non-reducing disk displacement of the TMJ were treated with pumping of the joint with injection of sodium hyaluronate. Chewing movement patterns in these patients were evaluated, using mandibular kinesiography (MKG) at their initial visit and at mean 19-month follow-up and the results were compared. Masticatory efficiency was also measured. As controls, 23 volunteers without TMJ dysfunction were employed. Far from the results of normal volunteers, chewing movement patterns of the patients on MKG did not show deviation to the chewing side in the TMJ-unaffected-side chewing in the horizontal plane. However, such patterns of the patients became similar to those of normal volunteers after treatment. Masticatory efficiency of the patients improved after treatment, though it was impaired at initial visit. The MKG and masticatory efficiency test appeared to be a useful method of comparing masticatory function before and after treatment in patients with non-reducing disk displacement of the TMJ.

Natural course of nonreducing disc displacement of the temporomandibular joint: changes in chewing movement and masticatory efficiency

PURPOSE

The purpose of this study was to examine changes of chewing movement and masticatory efficiency during the natural course of nonreducing disc displacement of the temporomandibular joint (TMJ).

PATIENTS AND METHODS

The subjects were 15 patients who had been diagnosed with nonreducing disc displacement of the TMJ but had received no treatment. Chewing movement and masticatory efficiency were examined at the initial visit and at a mean follow-up of 21.7 months, using mandibular kinesiography and adenosine triphosphate ebteric-coated granules. As a control, 23 persons who had no current or previous TMJ symptoms were studied.

RESULTS

The patients' clinical signs and symptoms tended to be alleviated during the follow-up period. In normal controls, chewing movement showed lateral excursion to the chewing side on both the right and left sides. In patients, chewing movement at the initial visit showed lateral excursion to the chewing side during chewing on the TMJ affected side, but no such deviation was noted during chewing on the TMJ unaffected side in the horizontal plane. However, chewing movement at follow-up became similar to that of controls. In patients, masticatory efficiency became better during the natural course, although that at follow-up did not always reach the control's level.

CONCLUSION

In untreated patients with nonreducing disc displacement of the TMJ, chewing movement and masticatory efficiency tend to improve spontaneously.