Effects of four treatment strategies for temporomandibular joint closed lock.

A previous randomized controlled trial (RCT) by Schiffman et al. (2007)(15) compared four treatments strategies for temporomandibular joint (TMJ) disc displacement without reduction with limited mouth opening (closed lock). In this parallel group RCT, 106 patients with magnetic resonance imaging (MRI)-confirmed TMJ closed lock were randomized between medical management, non-surgical rehabilitation, arthroscopic surgery, and arthroplasty. Surgical groups also received rehabilitation post-surgically. The current paper reassesses the effectiveness of these four treatment strategies using outcome measures recommended by the International Association of Oral and Maxillofacial Surgeons (IAOMS). Clinical assessments at baseline and at follow-up (3, 6, 12, 18, 24, and 60 months) included intensity and frequency of TMJ pain, mandibular range of motion, TMJ sounds, and impairment of chewing. TMJ MRIs were performed at baseline and 24 months, and TMJ tomograms at baseline, 24 and 60 months. Most IAOMS recommended outcome measures improved significantly over time (P≤0.0003). There was no difference between treatment strategies relative to any treatment outcome at any follow-up (P≥0.16). Patient self-assessment of treatment success correlated with their ability to eat, with pain-free opening ≥35mm, and with reduced pain intensity. Given no difference between treatment strategies, non-surgical treatment should be employed for TMJ closed lock before considering surgery.

Evidence of oxidative stress in temporomandibular disorders: a pilot study.

Oxidative stress is involved in the pathogenesis of many conditions and is caused by free radicals in concentrations that overwhelm the natural scavenging mechanisms and cause pain and inflammation. This investigation sought to determine whether pain from temporomandibular disorders was associated with increased oxidative stress as measured by biomarkers in saliva and serum. Both salivary and serum levels of the oxidative stress biomarkers including 8-hydroxydeoxyguanosine, malondialdehyde and total antioxidant status were compared in patients with mild and severe TMJD pain and with healthy controls. These biomarkers were determined spectrophotometrically in saliva and serum from 10 high TMJD pain patients, 10 low TMJD pain patients, and 10 healthy control subjects from National Institute of Dental Research's TMJ Implant Registry and Repository. Linear and logistic regression analyses were used to evaluate the association between each biomarker and TMJD pain. The mean levels of log 8-hydroxydeoxyguanosine (saliva P < 0·0001, serum P = 0·0008), malondialdehyde (saliva P = 0·002, serum P = 0·004) and total antioxidant status (saliva P = 0·005; serum P = 0·001) achieved statistically significant differences between groups. In linear regression analysis, both salivary and serum levels of each biomarker were associated with TMJD pain. In a multivariable analysis, again, both salivary levels and serum levels were also different between groups. Salivary levels of oxidative stress ratios of 8-hydroxydeoxyguanosine, malondialdehyde and total antioxidant status were significantly different between patients with TMJD pain and controls and was comparable to that in serum. These biomarkers hold promise as a potential diagnostic and therapeutic strategy.

Psychometric properties of the modified Symptom Severity Index (SSI).

The psychometric properties of the modified Symptom Severity Index were investigated to assess the relationships among dimensions of pain in temporomandibular disorders (TMD). The 15-item instrument is composed of ordinal scales assessing five pain dimensions (intensity, frequency, duration, unpleasantness and difficulty to endure) as experienced in three locations (temple, temporomandibular joint (TMJ), masseter). In 108 closed-lock subjects, Cronbach's alpha was used to measure internal consistency resulting in 31 of the 105 pair-wise comparisons >or=0.71. Multilevel exploratory factor analysis was used to assess dimensionality between items. Two factors emerged, termed temple pain and jaw pain. The jaw pain factor comprised the TMJ and masseter locations, indicating that subjects did not differentiate between these two locations. With further analysis, the jaw pain factor could be separated into temporal aspects of pain (frequency, duration) and affective dimensions (intensity, unpleasantness, endurability). Temple pain could not be further reduced; this may have been influenced by concurrent orofacial pains such as headache. Internal consistency was high, with alphas >or=0.92 for scales associated with all factors. Excellent test-retest reliability was found for repeat testing at 2-48 h in 55 subjects (Intra-class correlation coefficients = 0.97, 95%CI 0.96-0.99). In conclusion, the modified Symptom Severity Index has excellent psychometric properties for use as an instrument to measure pain in subjects with TMD. The most important characteristic of this pain is location, while the temporal dimensions are important for jaw pain. Further research is needed to confirm these findings and assess relationships between dimensions of pain as experienced in other chronic pain disorders.

Randomized effectiveness study of four therapeutic strategies for TMJ closed lock.

For individuals with temporomandibular joint (TMJ) disc displacement without reduction with limited mouth opening (closed lock), interventions vary from minimal treatment to surgery. In a single-blind trial, 106 individuals with TMJ closed lock were randomized among medical management, rehabilitation, arthroscopic surgery with post-operative rehabilitation, or arthroplasty with post-operative rehabilitation. Evaluations at baseline, 3, 6, 12, 18, 24, and 60 months used the Craniomandibular Index (CMI) and Symptom Severity Index (SSI) for jaw function and TMJ pain respectively. Using an intention-to-treat analysis, we observed no between-group difference at any follow-up for CMI (p > or = 0.33) or SSI (p > or = 0.08). Both outcomes showed within-group improvement (p < 0.0001) for all groups. The findings of this study suggest that primary treatment for individuals with TMJ closed lock should consist of medical management or rehabilitation. The use of this approach will avoid unnecessary surgical procedures.

Broad support sought for emerging specialty of orofacial pain.

The American Dental Association is considering giving the emerging field of orofacial pain full status as a new dental specialty. Many recent advances in the neuroscience of orofacial pain have lead to treatments by orofacial pain dentists that provide significant relief for patients with chronic disorders. However, access to this care has been limited, leaving many patients to continue to suffer. Recent efforts to improve this situation by developing the field into a specialty have received broad support among dentists and have increased awareness of the benefits this field can provide for dentists and their patients.

Atypical orofacial pain disorders: a study of diagnostic subtypes.

Atypical facial pain is a persistent pain in the face or intraoral region that does not fit into the diagnostic criteria associated with specific orofacial pain disorders. This article presents the results of a study, which showed that in most cases of presumed atypical facial pain, there is a specific physical diagnosis or multiple diagnoses that causes the persistent pain. These difficult to diagnose disorders are reviewed with discussion of future research that is needed in this area.

SYM-2081 a kainate receptor antagonist reduces allodynia and hyperalgesia in a freeze injury model of neuropathic pain.

Cold-freeze injury at -4 degrees C to the rat sciatic nerve produces mechanical allodynia and thermal hyperalgesia [M.A. Kleive, P.S. Jungbluth, J.A. Uhlenkamp, K.C. Kajander, Cold injury to rat sciatic nerve induces thermal hyperalgesia or analgesia, 8th World Congress on Pain, Vancouver, BC, Canada, August 1996 (Abstract).]. The NMDA receptor, an excitatory amino acid (EAA) receptor, appears to be involved in the development of allodynia and hyperalgesia following nerve injury. The role, if any, of the kainate receptor, another EAA receptor, remains unknown. In the current study, we evaluated whether (2S,4R)-4-methylglutamic acid (SYM-2081), a recently developed kainate receptor antagonist, attenuates increased responsiveness following cold injury to the sciatic nerve. During baseline testing, Sprague-Dawley rats were evaluated for frequency of withdrawal from von Frey filaments and latency of withdrawal from a radiant thermal source. Animals were then anesthetized, the left sciatic nerve was exposed, and the nerve was cooled to -4 degrees C for 15 min (n=24). For control rats (n=24), all procedures were identical except that the nerve was maintained at 37 degrees C. Testing resumed on the third day following surgery. On the fifth post-operative day, SYM-2081 (150 or 100 mg/kg), fentanyl citrate (0. 04 mg/kg) or vehicle was injected intraperitoneally. Injury to the rat sciatic nerve induced a significant increase in withdrawal frequency and a significant decrease in withdrawal latency (ANOVA, p<0.05). SYM-2081 and fentanyl significantly reduced these responses (p<0.05). These results suggest that kainate and opioid receptors are involved in the mechanical allodynia and thermal hyperalgesia that develop following cold injury to the sciatic nerve.

Broad support evident for the emerging specialty of orofacial pain.

The emerging field of orofacial pain is being considered by the American Dental Association for full status as a new dental specialty to improve the care for these patients. The broad support among dentists for this initiative stems from an awareness of the benefits the field can provide for dentists and their patients.

Broad support evident for the emerging specialty of orofacial pain.

The emerging field of Orofacial Pain is being considered by the American Dental Association for full status as a new dental specialty. Many recent advances in the neuroscience of orofacial pain have lead to treatments by orofacial pain dentists that provide significant relief for patients with chronic orofacial pain disorders. However, access to this care has been limited leaving many patients to continue to suffer. Subsequently, recent efforts to improve this by developing the field into a specialty have shown broad support among dentists and increased awareness of the benefits this field can provide for dentists and their patients. A recent survey of 805 individuals in the general population who reported having a persistent pain disorder revealed that more than four out of 10 people have yet to find adequate relief, saying their pain is out of control-despite having the pain for more than 5 years and switching doctors at least once. "This survey suggests that there are millions of people living with severe uncontrolled pain," says Russell Portenoy, MD, President of the American Pain Society. "This is a great tragedy. Although not everyone can be helped, it is very likely that most of these patients could benefit if provided with state-of-the-art therapies and improved access to pain specialists when needed." (1). Development of the field of Orofacial Pain into a dental specialty has been motivated primarily by this issue; patients with complex chronic orofacial pain disorders have not been historically treated well by any discipline of health care. Recent studies of chronic orofacial pain patients have found that these patients have a high number of previous clinicians and have endured many years with pain prior to seeing an orofacial pain dentist (2) (Fig. 1). Complex pain patients and the clinicians who see them are often confused about whom they should consult for relief of the painful disorder. Treatment for these patients within the existing structure of dental or medical specialties has been inadequate and millions of patients are left suffering. Insurers are also confused with regard to reimbursement and make decisions to exclude treatment for orofacial pain disorders under both dental and medical policies. However, Dentistry has taken a leading role in health care to address this national problem by developing the field of Orofacial Pain into a dental specialty. A study of dentists and dental specialists have shown that there is a recognized need and broad support for further development of this field into a new dental specialty(3).

Masticatory myofascial pain: an explanatory model integrating clinical, epidemiological and basic science research.

Masticatory myofascial pain (MMP) is a regional muscle pain disorder characterized by localized muscle tenderness in taut bands of skeletal muscles and pain and is one of the most common causes of persistent regional pain. The affected muscles may also display an increased fatigability, stiffness, subjective weakness, pain in movement, and slight restricted ROM that is unrelated to joint restriction. Although the exact etiology of MMP is unclear, recent research has improved our understanding of factors that contribute to the development and progression of MMP. Understanding these factors can help to validate an explanatory model for etiology and treatment of MMP. This model includes peripheral mechanisms from local biomechanical strain leading to the onset of early cases of MMP while central mechanisms associated with psychosocial factors lead to increased chronicity of MMP. As MP persists, chronic pain characteristics often precede or follow it's development. Management of the syndrome naturally follows from this model with therapy to rehabilitate the trigger points (TrPs) while focusing effort on reducing all contributing factors.

[Diagnosis and treatment of myofascial pain]. / Diagnostiek en behandeling van myofasciale pijn.

Myofascial pain (MFP) is a regional muscle pain disorder characterized by localized muscle tenderness and pain and is the most common cause of persistent regional pain. MFP is frequently overlooked as a diagnosis because it is often accompanied by signs and symptoms in addition to pain, coincidental pathology conditions, and behavioral and psychosocial problems. Evaluation of myofascial pain includes locating the trigger points and muscles involved as well as recognition of these contributing factors. Management of the syndrome follows with palliative care, splint therapy, muscle exercises, therapy to the trigger points, and behavioral therapy that depends on complexity of the case. The short term goals is to restore the muscle tot normal length, posture, and full joint range of motion with exercises and trigger point therapy. The long term goals include reducing the symptoms and their negative effects while helping the patient return to normal function without need for further health care. The difficulty in managing MFP lies in the critical need to match the level of complexity of the management program with the complexity of the patient. Failure to address the entire problem through a team approach if needed, may lead to failure to resolve the pain and perpetuation of a chronic pain syndrome.

Predictors of outcome for treatment of temporomandibular disorders.

Psychosocial factors have been frequently suggested as important risk factors that may delay recovery in patients with temporomandibular disorders. In this study, 94 subjects with chronic temporomandibular disorders were studied using IMPATH:TMJ prior to their entering an interdisciplinary treatment program to determine which factors were most predictive of outcome. Treatment outcome was determined based on significant decreases in the Craniomandibular Index and the Symptom Severity Index from pretreatment to posttreatment. The IMPATH:TMJ items were regressed on treatment outcome for a random sample of half of the subjects (n = 47) to isolate the psychosocial and demographic items most predictive of treatment response. Discriminant analysis was then employed to test the predictive utility of the identified items for these subjects (criterion group), followed by a cross-validation of the items on the remaining 47 subjects (cross-validation group). Low self-esteem, feeling worried, low energy, and sleep activity were identified as useful predictors of treatment outcome for the criterion group. Each are correlates of depression. The discriminant analysis employing these four items accounted for 49% of the variance in treatment response, was statistically significant (P < .0001), and correctly predicted treatment outcome for 41 of 47 subjects (87%) in the criterion group. The predictive utility of the identified items remained statistically significant when applied to the cross-validation group (P < .01). The discriminant function employing the items correctly predicted treatment outcome for 37 of 47 subjects (79%) and explained 28% of the variance in treatment response. Findings of this study suggest that pretreatment psychosocial information is important in predicting treatment outcome for chronic temporomandibular disorders, and that symptoms of depression mediate treatment response for chronic pain patients.

Recent advances in orofacial pain and temporomandibular disorders.

The field of orofacial pain and temporomandibular disorders (OFP/TMD) is a relatively new area of clinical and scientific interest that parallels the expanding interest in pain conditions in the back and other areas of the body. This new field is concerned with the understanding and care of patients with disorders that cause pain and dysfunction of the masticatory system and related orofacial, head, and neck structures. Because orofacial structures are integrally involved in communication, sustenance, sexuality, appearance, and self esteem, the personal impact of these disorders can be high, motivating patients to seek care and be a significant part of the clinical practice of dentistry and medicine. As a result of recent developments in research, education, and patient care in the past 10 years, significant progress has been made in helping patients with these disorders. These efforts can provide an example of what can be done with other pain disorders to advance efforts in research, teaching, and patient care. The purpose of this paper is to review these recent advances in OFP/TMD and their implications for patient care.

Myofascial pain of the head and neck: diagnosis and management.

Myofascial pain (MFP) is a regional muscle pain disorder characterized by localized muscle tenderness and pain and the most common causes of persistent pain in the head and neck. The affected muscles may also display an increased fatigability, stiffness, subjective weakness, pain in movement, and slight restricted range of motion that is unrelated to joint restriction. MFP is frequently overlooked as a diagnosis because it is often accompanied by signs and symptoms in addition to pain, coincidental pathology conditions such as joint disorders, and behavioral and psychosocial problems. As MFP persists, chronic pain characteristics often precede or follow its development. Evaluation of myofascial pain includes locating the trigger points and muscles involved as well as recognition of these contributing factors. Management of the syndrome naturally follows with muscle exercises, therapy to the trigger points, and reducing all contributing factors. The difficulty in managing MFP lies in the critical need to match the level of complexity of the management program with the complexity of the patient.

Management of masticatory myofascial pain.

Masticatory myofascial pain is a relatively frequent occurrence in patients seen by the orthodontist. Thus it is important to understand the management of this condition. Treatment is generally directed toward the restoration of a more physiological state in the muscles of mastication and involves medications, appliances, various forms of behavioral modification, as well as the use of muscle exercises and trigger point therapy. This article focuses on the role of the latter modalities in the management of myofascial pain and dysfunction.

Myofascial pain.

MFP is a regional muscle pain disorder characterized by localized muscle tenderness and pain and is the most common cause of persistent regional pain. The affected muscles may also display an increased fatiguability, stiffness, subjective weakness, pain on movement and slightly restricted range of motion that is unrelated to joint restriction. MFP is frequently overlooked as a diagnosis because it is often accompanied by signs and symptoms in addition to pain, coincidental pathological conditions, and behavioural and psychosocial problems. Chronic pain characteristics often precede or follow the development of MFP. Evaluation of MFP includes locating the trigger points and muscles involved as well as recognition of the contributing factors. Management of the syndrome naturally follows with muscle exercises, therapy to the trigger points, and reduction of all the contributing factors. The short-term goal is to restore the muscle to normal length and posture and full joint range of motion with exercises and trigger point therapy. The long-term goals include reducing the symptoms and their negative effects while helping the patient return to normal function without the need for future health care. The difficulty in managing MFP lies in the critical need to match the level of complexity of the management programme with the complexity of the patient's situation. Failure to address the entire problem, through a team approach if needed, may lead to failure to resolve the pain and perpetuation of a chronic pain syndrome.

Evaluation of a training program intended to calibrate examiners of temporomandibular disorders.

The adequacy of a training program intended to calibrate examiners of temporomandibular disorders (TMD) was evaluated. Eight examiners blindly rated 12 subjects with various TMD signs and symptoms after participating in a 5-h intense training procedure. Some examiners had earlier experience of TMD examinations, and some were newly trained. The Craniomandibular Index was used as the assessment instrument. Agreement within the whole group of examiners was low. Training tended to increase the probability of correctly registering signs. It is concluded that the program was not sufficient to create reliability among multiple examiners. More extensive training, not only to a standard but also between the different examiners, appears necessary. Revision of the examination technique is suggested, and recommendations for strengthening the calibration procedures are made.

The relationship between level of mandibular pain and dysfunction and stage of temporomandibular joint internal derangement.

Temporomandibular joint internal derangement (TMJ ID) is the most common intra-articular TM disorder and can progress from TMJ ID with reduction to TMJ ID without reduction. It is not known whether this anatomical progression is associated with increasing levels of mandibular dysfunction. The objective of this study was to determine whether the level of clinically detectable mandibular dysfunction was related to the stage of TMJ ID. Two clinicians examined 42 subjects prior to bilateral TMJ arthrographic evaluation. The level of mandibular dysfunction was calculated by Helkimo's Clinical Dysfunction Index (Di) and the Craniomandibular Index (CMI). Statistical analysis revealed that the level of mandibular dysfunction as determined by the Di and CMI was not related to the arthrographic presence or absence of TMJ ID. Therefore, the clinician cannot assume that the level of mandibular dysfunction is directly related to the absence or presence of TMJ ID. Epidemiologically, the CMI and Di can be used only for estimation of the degree of mandibular dysfunction, since they do not provide direct information on a specific TM disorder.