Appraisal

Objectives The present paper is a reappraisal of the data used by Reston and Turkelson in the first available published meta-analysis of temporomandibular joint surgery.

Study design A systematic review of the data, as used by the authors, was critically evaluated, using additional inclusion criteria.

Results Of all the citations reviewed, 23 out of 30 cited studies were found to meet the current inclusion criteria.

Conclusion Although the available literature consists of retrospective and prospective case series and two randomised control trials (RCT). It appears that the newer techniques of arthrocentesis and arthroscopy are associated with higher success rates than the techniques most common in the past, such as discectomy and disc repair.

Introduction

Temporomandibular disorder causes pain and dysfunction in many patients world-wide. A small proportion of the patients do not improve following conservative therapies.1 Numerous open joint procedures were developed to reposition and reshape the displaced disc or deformed disc. Today, these modalities range from a minimally invasive technique such as arthroscopy to open temporomandibular joint surgery. Arthroscopic surgery is believed to be less invasive than open temporomandibular joint surgery. It is unclear to what degree arthroscopy is superior, however. Open temporomandibular surgery requires increased intra-operative time and greater risk to adjacent tissues or structures.

Currently, there is a lack of published prospective, randomised studies with long-term results to assist the surgeon in choosing a particular option, and therefore the personal experience of the surgeon may become the determining factor controlled trials as pointed out by Reston and Turkelson in the paper above.

Methods

We devised similar methodological criteria for analysing the same articles as those selected in the above paper. We used the following section criteria:

  1. 1)

    At least 10 patients must have enrolled in the study.

  2. 2)

    Patients included had DDw/oR.

  3. 3)

    Articles should report on the different treatments: arthrocentesis, arthroscopy, discectomy and disc repair.

The other criteria for inclusion were:

  1. 1)

    Follow-up duration of 12 months or longer.

  2. 2)

    Improvement is based on measurable increase in maximal mouth-opening.

Results

Of the papers that were highlighted, four articles were excluded because of short time periods or included patients with DDw/oR. For the purpose of analysis, several discrete treatment types were identified in the 23 selected articles. These included:

Arthrocentesis. This is the simplest and least invasive of all the surgical techniques. It involves the placement of two needles in the superior joint space for lavage and instillation of corticosteroid or sodium hyaluronate to treat internal derangement.

Arthroscopy. This is the placement of an arthroscope with an attached camera into the superior space for examination, lavage, lysis, and arthroplasty and disc stabilisation.

Disc repair is the reposition of the articular disc to a more normal anatomical relation with the condyle and the fossa is usually undertaken when the disc is displaced but free of disease or structural deformity.

Discectomy is the complete removal of the disc. It was one of the first intra-articular temporomandibular-joint surgical procedures described. Discectomy is undertaken when the disc is found to be diseased or structurally compromised as a result of tears, perforations or persisting symptoms of pain and dysfunction after surgery.

The individual papers, with treatment, type of study, sample number and improvement, are listed in Table 1. The results indicate that arthrocentesis gives the greatest degree of improvement after intervention, compared with the historical control of discectomy and disc repair. The comparison of arthroscopy and arthrocentesis, however, showed that enrolled numbers in trials for arthroscopy were greater (Figure 1).

Table 1 Summary of studies used in the meta-analysis.
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Figure 1
figure 1

Summary of success by treatment type.

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Discussion

The purpose of this investigation was to systematically evaluate the treatments that have been described for the treatment of the temporomandibular joint with DDw/oR. Unfortunately, the substantial degree of variability within individual studies precludes a quantitative analysis of the data. Applying a uniform quantitative analysis to control variables and unify data could be misleading.

Regardless of the differences in patient population, some useful analysis can be carried out by applying systemic review methods to the studies. A total of 23 papers provided enough data to allow an assessment of the effect of treatment on success rate. We acknowledge that these studies are not equal in value, however. For the treatments described, the one most likely to be successful for DDw/oR appears to be arthrocentesis, with the next most successful being arthroscopy.

Arthrocentesis has emerged as an excellent treatment in people who have recent onset of painful limitation of mandibular opening. Nitzan et al2 were the first to have reported on clinical outcomes in 39 patients who underwent arthrocentesis of 40 joints. Other studies have specifically compared the results of arthrocentesis and arthroscopy. Fridrich et al3 performed a prospective study in 19 patients with internal derangement unresponsive to nonsurgical therapy randomised into arthroscopy and arthrocentesis groups. The authors reported 82% success for the arthroscopy group and 75% with the arthrocentesis group, based on improvement in maximum incisal opening and subjective pain scores. This was deemed not significant different by the authors. Another investigator, Murakami4 compared the efficacy of nonsurgical therapy, arthrocentesis and arthroscopy in 108 patients with internal derangement and closed lock. Arthrocentesis had a success rate of 70% whereas for arthroscopy this was 91%, the author again concluding that the difference was not significant.

Conclusion

Based on this analysis, we conclude that disc repair and discectomy are good historical controls. Surgical arthrocentesis and arthroscopy are effective for DDw/oR patients. Better-designed trials are needed before one can accurately determine the magnitude of the benefits of temporomandibular articular surgery.