This study analysed the prognostic factors for successful arthrocentesis with and without sodium hyaluronate (SH) injection for the treatment of temporomandibular joint (TMJ) disc displacement without reduction (DDwoR) using clinical and radiological results. 29 TMJs in 25 patients with DDwoR were included. Patients were treated with arthrocentesis or arthrocentesis followed by intra-articular (i.a.) injection of SH. Treatment was evaluated for postoperative range of maximum mouth opening and the degree of postoperative pain on a VAS. Prognostic factors analysed were age, sex, duration of locking, trauma history, previous TMJ treatment, depression, bruxism, malocclusion and missing teeth. Degenerative changes were evaluated as probable prognostic factors. After treatment, 24 joints (83%) fulfilled the criteria for success. Duration of locking and present preoperative degenerative changes were the most significant factors for treatment outcome. The results suggest it is sufficient to use only arthrocentesis in patients without preoperative degenerative changes and arthrocentesis with SH in patients with degenerative changes on their preoperative MRIs, but because there were some significant differences between the two groups preventing the authors from comparing them statistically, they cannot come to that conclusion. To clarify the use of SH in such cases, standardized study groups are necessary for future studies.
Many clinical studies suggest that splint therapy , arthrocentesis , arthroscopic lysis and lavage , and arthrotomy are effective for the signs and symptoms of temporomandibular joint (TMJ) disorders. TMJ arthrocentesis, the least invasive and the simplest of all surgical techniques, is highly successful in re-establishing a normal range of mouth opening in patients with closed lock . Sodium hyaluronate (SH) is also successful, playing an important role in joint lubrication and protection of the cartilage in TMJ internal derangements , but it is not clear which cases will respond to this procedure. It is important to understand the indications and limitations for arthrocentesis.
Arthrocentesis is most commonly used to treat patients with anteriorly displaced discs without reduction (closed lock) or those with disc adhesion (stuck disc). It can also be used as a palliative procedure for patients with acute episodes of degenerative or rheumatoid arthritis and to relieve pain in patients with painful clicking in the TMJ that does not respond to medical management .
Some studies evaluate specific variables in relation to specific treatment outcome measures . E mshoff investigated whether clinical variables such as age, gender, time since pain onset, pain level, and mandibular range of motion, predict treatment outcome for arthrocentesis. A lpaslan et al. examined the factors affecting the outcome of arthrocentesis, and concluded that a history of clenching or bruxism and the duration of symptoms before arthrocentesis had no effect on treatment outcome .
The purpose of this study is to determine the possible prognostic factors affecting treatment outcome by examining the clinical and radiological effects of arthrocentesis with and without the injection of SH for the treatment of TMJ disc displacement without reduction (DDwoR).
Materials and methods
This study was carried out with the approval of the Istanbul University Ethics Committee of School of Medicine (2006/1204) and informed consent was obtained from all patients.
Patients included in this study had been referred to the authors’ institution with TMJ pain and limited mouth opening between August 2006 and December 2007. 29 TMJs in 25 patients (2 males, 23 females, aged 17–64 years, mean 30.4 years) with a clinical and radiological diagnosis of TMJ DDwoR were included in this study. Patients with previous TMJ surgery, systemic inflammatory joint disease, condylar hypoplasias/hyperplasias/tumours and patients with contraindications for arthrocentesis and MRI were not included in the study.
Patients were divided into two groups depending on whether they could afford SH injections. One group was treated with only arthrocentesis (group A: 14 TMJs in 13 patients) and the other group was treated with intra-articular SH injection following arthrocentesis (group SH: 15 TMJs in 12 patients) depending on whether the patient provided SH. In group A, one patient had bilateral arthrocentesis and in group SH, three patients had bilateral SH injections following arthrocentesis.
In both groups, stabilization splints were used as described by O keson for all patients. Arthrocentesis was performed under local anaesthesia according to the technique described by N itzan et al. . In group SH, 1 ml of SH was injected into the upper joint compartment following arthrocentesis. Stabilization splints were used only during the night for 6 months, and occlusal adjustments were made on each appointment. Patients were asked to eat a soft diet following arthrocentesis for 1 week and given active and passive mouth-opening exercises beginning on postoperative day 7.
The research diagnostic criteria for TMJ disorders prepared by Samuel F. Dworkin and Linda Le Reche was used to score the patients’ depression symptoms . The patients were asked 20 questions, such as whether they felt low in energy, thought of death or dying, had poor appetite, and felt lonely. The answers were recorded as not at all (0), a little bit (1), moderately (2), quite a bit (3) and extremely (4). The total score was divided by the number of questions answered .
The patients were clinically evaluated before the procedure, on postoperative day 7, after 2, 3 and 4 weeks, and 2, 3, 4, 5, 6 and 12 months postoperatively. Intensity of the joint pain was assessed using a visual analog scale (VAS; 0–10), maximum mouth opening (MMO) was recorded at each follow-up visit, and TMJ sounds and palpation scores were noted as positive or negative.
To evaluate clinical success at the end of 12 months, the criteria proposed by the American Association of Oral and Maxillofacial Surgeons in 1995 was used . The criteria were: a level of pain that is of little or no concern to the patient; MMO 35 mm or more; improvement in the ability to masticate a normal or nearly normal diet; functional and stable occlusion; limited period of disability and acceptable clinical appearance. Prognostic factors analysed were age, sex, duration of locking, trauma history, previous treatment, depression scores, bruxism habit, malocclusion and missing teeth. Bone marrow oedema and narrowed joint space on the preoperative MRIs were also evaluated ( Tables 1 and 2 ). Cortical bone defining the joint surface may not always be demonstrated well by MRI, but a subjective assessment evaluating the joint space was carried out by the same radiologist thinking that it might add valuable data to the overall investigation.
|Successful cases ( n = 24)||Unsuccessful cases ( n = 5)||P|
|Duration of locking (months)||Mean, 3.92; range, 0.1–24||Mean, 9.6; range, 1–24||0.039 *|
|Trauma history||2/24 (8.3%)||1/5 (20%)||0.446|
|Previous treatment||4/24 (16.7%)||0 (0%)||1.000|
|Bone marrow oedema in preoperative MRI||5/24 (20.8%)||3/5 (60%)||0.112|
|Narrowed joint space in the preoperative MRI||13/24 (54.2%)||1/5 (20%)||0.330|
|Successful cases ( n = 21)||Unsuccessful cases ( n = 4)||P|
|Age (year)||Mean, 31.57; range, 17–64||Mean, 24.25; range, 18–41||0.169|
|Male||2/21 (9.5%)||0 (0%)||1.000|
|Female||19/21 (90.5%)||4/4 (100%)|
|Depression scores||Mean, 0.717; range, 0.19–2.94||Mean, 0.936; range, 0.31–2.94||0.628|
|Bruxism||17/21 (81%)||3/4 (75%)||1.000|
|Malocclusion||8/21 (38.1%)||1/4 (25%)||1.000|
|Missing teeth||7/21 (33.3%)||1/4 (25%)||1.000|
Magnetic resonance imaging
MRI studies were obtained with a 1.0 T MR scanner (Siemens Magnetom Impact, Erlangen, Germany) in closed and maximum open mouth positions using coronal and sagittal T1 (TR/TE; 480/15 ms) and sagittal T2-weighted (TR/TE; 3000/90 ms) pulse sequences. A single parasagittal slice perpendicular to the long axis of the condylar process on the axial localizer was placed on both TMJs using a gradient echo sequence ( flash 2D , TR/TE/FA; 35/12 ms, 45) with the aid of a nonferromagnetic intermaxillary device to obtain the various mouth-opening positions. Sequential bilateral images were made at the closed mouth and the various mouth-opening positions that led to maximum mouth opening. These images, which depicted the disc, condyle, articular eminence, and glenoid fossa, were evaluated especially for the dynamic disc–condyle relationship.
MRI was performed before and 12 months after treatment in both groups. Disc form, disc location during neutral position, reduction with movement, joint effusion, range of motion (ROM), degenerative changes of the articular surfaces such as osteophytes, erosion and bone marrow oedema were evaluated on the preoperative and postoperative MRIs of all patients ( Table 3 ).
|Group A||Group SH|
|n (%)||N (%)|
|Normal||1 (7.1%)||0 (0%)|
|Deformed||13 (92.9%)||15 (100%)|
|Deformed||14 (100%)||15 (100%)|
|No||14 (100%)||15 (100%)|
|No||11 (78.6%)||12 (80.0%)|
|Moderate *||1 (7.1%)||0 (0%)|
|Yes||2 (14.3%)||3 (20.0%)|
|0||1 (7.1%)||1 (6.7%)|
|1||9 (64.3%)||8 (53.3%)|
|2||4 (28.6%)||6 (40.0%)|
|0||12 (85.7%)||12 (80.0%)|
|1||2 (14.3%)||2 (13.3%)|
|2||0 (0%)||1 (6.7%)|
|Range of motion|
|Limited||10 (71.4%)||9 (60.0%)|
|Moderate||3 (21.4%)||5 (33.3%)|
|Normal||1 (7.1%)||1 (6.7%)|
|Limited||0 (0%)||6 (40.0%)|
|Moderate||6 (42.9%)||5 (33.3%)|
|Normal||8 (57.1%)||4 (26.7%)|
|+||9 (64.3%)||10 (66.7%)|
|−||5 (35.7%)||5 (33.3%)|
|+||10 (71.4%)||11 (73.3%)|
|−||4 (28.6%)||4 (26.7%)|
|+||3 (21.4%)||12 (80.0%)|
|−||11 (78.6%)||3 (20.0%)|
|+||4 (28.6%)||13 (86.7%)|
|−||10 (71.4%)||2 (13.3%)|
|Erosion (articular eminence)|
|+||0 (0.0%)||5 (33.3%)|
|−||14 (100.0%)||10 (66.7%)|
|+||1 (7.1%)||5 (33.3%)|
|−||13 (92.9%)||10 (66.7%)|
|Bone marrow oedema|
|+||0 (0%)||8 (53.3%)|
|−||14 (100%)||7 (46.7%)|
|+||0 (0%)||9 (60.0%)|
|−||14 (100%)||6 (40.0%)|
All preoperative and postoperative MRI results were evaluated by a neuroradiologist (S.S.) who was unaware of the patients’ clinical information before and after the treatment.
Normal disc position was defined by location of the posterior band of the disc at the superior or 12 o’clock position relative to the condyle. Types of internal derangement were categorized as displaced without reduction, if the disc was displaced anteriorly with no change in position during mouth opening, or displaced with reduction, if during any stage of mouth opening, the disc resumed its normal position. Slight movement of the anteriorly displaced disc back to its normal position is evaluated as a moderate reduction in this study ( Table 3 ). The form of the disc was recorded as normal or deformed connoting the presence of signs of degeneration.
On T2-weighted images, joint effusion was identified as an area of high signal intensity in the region of the upper or lower joint space. More than a line of high signal in at least two consecutive sections was considered positive for TMJ effusion and was recorded as none (0), moderate (1) or high (2) using a subjective assessment.
ROM is the range of condylar movement and it was recorded as limited when there was almost no condylar movement, moderate when there was slight condylar movement or normal when there was no limitation in the condylar movement as a result of the subjective assessment of the radiologist.
The MRI diagnosis of degenerative bony changes was defined by the presence of flattening, surface irregularities, osteophytes or erosion. It was recorded as negative (0) or positive (1). Bone marrow oedema was defined by the presence of a hypointense signal on T1-weighted and a hyperintense signal on T2-weighted images and recorded as negative (0) or positive (1).
Significance was set at P < 0.05. For all statistical analysis, the SPSS x package (15.0 Version; SPSS Inc., Chicago, IL, USA) was used. The Mann–Whitney U -test and Fisher’s exact test were used to evaluate the prognostic factors ( Tables 1 and 2 ). The χ 2 test was used to compare the success rates ( Table 4 ) of the two groups.