Temporomandibular joint dysfunction syndrome: a close association with systemic joint laxity (the hypermobile joint syndrome)

Prevalence and quality of temporomandibular disorders, chronic pain and psychological distress in patients with classical and hypermobile Ehlers-Danlos syndrome: an exploratory study

BACKGROUND

The Ehlers-Danlos syndromes are a group of clinically and genetically heterogeneous hereditary diseases affecting the connective tissue. They are characterized by hypermobility of the joints, hyperextensible skin and friable tissue. According to current classification, 13 subtypes can be distinguished, of which the hypermobile and the classical subtype are the most prevalent. This study aimed to evaluate patients with classical (cEDS) and hypermobile (hEDS) Ehlers-Danlos syndrome regarding temporomandibular disorder (TMD), chronic pain, and psychological distress.

METHODS

Support groups from Germany, Austria, and Switzerland were contacted, and social media were used to recruit participants. Free text questions, the German version of the Depression Anxiety and Stress Scale (DASS), and the German version of the Graded Chronic Pain Status (GCPS) were used.

RESULTS

259 participants were included (230 hEDS/29 cEDS). At least 49.2% of the participants had painful or restricted jaw movements, and at least 84.9% had pain in the masticatory muscles, with 46.3% already having a diagnosed TMD. Multivariate analysis showed a significant correlation between TMJ involvement and chronic pain with a 2.5-fold higher risk of chronic pain with a diagnosed TMD. 22.8% of participants had a critical score for depression, 53.3% had a critical score for anxiety, and 34.0% had a critical score for stress.

CONCLUSION

There is a high prevalence of TMD problems and chronic pain in patients with cEDS and hEDS. The lack of knowledge about these problems can create psychological distress. More research is needed to provide adequate treatment for patients with EDS.

Increased Prevalence of Generalized Joint Hypermobility Observed in Patients With Recurrent Temporomandibular Joint Dislocation

BACKGROUND

Generalized joint hypermobility (GJH), determined by the Beighton score, is a fundamental part of diagnosing benign joint hypermobility syndrome (BJHS), which may also present extra-articular manifestations, and is determined by the Brighton criteria.

PURPOSE

This study was designed to investigate whether there is an association between recurrent temporomandibular joint (TMJ) dislocation and these disorders.

STUDY DESIGN, SETTING, AND SAMPLE

A retrospective cross-sectional study was conducted. Hospital-based patients with a history of recurrent TMJ dislocation were compared to population-based patients that did not experience TMJ dislocations or any other TMJ disorders. Age and sex matching were performed between the study groups. All subjects reached the age of skeletal maturity.

PREDICTOR VARIABLE

A history of recurrent TMJ dislocations.

MAIN OUTCOME VARIABLES

Measurements of Beighton score (range from 0 to 9 with a score of ≥ 4 indicating GJH) and correspondence to the Brighton criteria (with at least two "major" criteria or one "major" criterion plus two "minor" criteria or four "minor" criteria indicating BJHS).

COVARIATES

Included age and sex.

ANALYSES

Mann-Whitney U-test for continuous variables and the χ² test or Fisher's exact test for categorical variables. Statistical significance was set at P < .05.

RESULTS

A total of 68 participants were included, of whom 34 patients presented with recurrent TMJ dislocations compared with a control population of 34. The Mean participants were 31.35 ± 8.06 years, and 29.4% (n = 20) were males. Of the dislocation group, 16 (47.0%) patients had a Beighton score of 4 or higher. The Beighton sum score was significantly higher, with a TMJ dislocation group mean score of 3.06 ± 2.8, compared with a control score of 0.82 ± 1.1 (P = .001). A total of 58.8% (n = 20) of the TMJ dislocation group participants met the Brighton criteria versus none (0.0%) of the control group (P = .001).

CONCLUSION

We found an association between recurrent TMJ dislocation and GJH. An association with BJHS was also found, based mainly on articular manifestations. Early detection of these disorders in patients suffering from recurrent TMJ dislocation may help identify individuals at increased risk for joint instabilities and allow the implementation of appropriate preventive management strategies.

Neurodevelopmental atypisms in the context of joint hypermobility, hypermobility spectrum disorders, and Ehlers-Danlos syndromes

Joint hypermobility (JHM), defined as an increased range of joint motion, is a frequent somatic trait in the general population but also the hallmark of many of the hereditary disorders of connective tissue. Ehlers-Danlos syndromes (EDS) belong to this group of diseases and are characterized by tissue fragility, skin abnormalities, and JHM. Between JHM and EDS, there are the so-called hypermobility spectrum disorders (HSD), which is an umbrella term referring to people with symptomatic JHM who do not fulfill criteria for a syndromic connective tissue disorder such as EDS. Among the variety of clinical correlates of JHM/HSD/EDS, neurodevelopmental atypisms are common although often not screened for and identified in the clinical setting. This article reviews the pertinent literature concerning neurodevelopmental conditions for which there is some evidence of an association with JHM/HSD/EDS. These include hyperactivity and attention deficit, learning, communication, and motor problems including tic disorders such as Tourette syndrome and autism spectrum disorders. Underlying mechanism hypotheses for such interconnections are also reviewed. The coexistence of connective tissue-altered conditions and neurodevelopmental atypisms increases disability in patients from an early age. Thus, increased awareness among clinicians and researchers is necessary to promote assessment, diagnosis, and develop management strategies to meet the specific needs of those affected.

A Novel Method of Temporomandibular Joint Hypermobility Diagnosis Based on Signal Analysis

Despite the temporomandibular joint (TMJ) being a well-known anatomical structure its diagnosis may become difficult because physiological sounds accompanying joint movement can falsely indicate pathological symptoms. One example of such a situation is temporomandibular joint hypermobility (TMJH), which still requires comprehensive study. The commonly used official research diagnostic criteria for temporomandibular disorders (RDC/TMD) does not support the recognition of TMJH. Therefore, in this paper the authors propose a novel diagnostic method of TMJH based on the digital time–frequency analysis of sounds generated by TMJ. Forty-seven volunteers were diagnosed using the RDC/TMD questionnaire and auscultated with the Littmann 3200 electronic stethoscope on both sides of the head simultaneously. Recorded TMJ sounds were transferred to the computer via Bluetooth^® for numerical analysis. The representation of the signals in the time–frequency domain was computed with the use of the Python Numpy and Matplotlib libraries and short-time Fourier transform. The research reveals characteristic time–frequency features in acoustic signals which can be used to detect TMJH. It is also proved that TMJH is a rare disorder; however, its prevalence at the level of around 4% is still significant.

Treatment of temporomandibular joint luxation: a systematic literature review

Objectives

To evaluate the effectiveness of surgical and nonsurgical treatment of temporomandibular joint (TMJ) luxation.

Materials and methods

This systematic literature review searched PubMed, the Cochrane Library, and Web of Science databases to identify randomized controlled trials on TMJ luxation treatment published between the inception of each database and 26 March 2018.

Results

Two authors assessed 113 unique abstracts according to the inclusion criteria and read nine articles in full text. Eight articles comprising 338 patients met the inclusion criteria, but none of these evaluated surgical techniques. Three studies including 185 patients concerned acute treatment with manual reduction of luxation while five studies including 153 patients evaluated minimally invasive methods with injection of autologous blood or dextrose prolotherapy for recurrent TMJ luxation. These studies reported that mouth opening after treatment was reduced and that independent of type of injection, recurrences of TMJ luxation were rare in most patients.

Conclusions

In the absence of randomized studies on surgical techniques, autologous blood injection in the superior joint space and pericapsular tissues with intermaxillary fixation seems to be the treatment for recurrent TMJ luxation that at present has the best scientific support. Well-designed studies on surgical techniques with sufficient numbers of patients, long-term follow-ups, and patient experience assessment are needed for selection of the optimal surgical treatment methods.

Clinical relevance

Autologous blood injection combined with intermaxillary fixation can be recommended for patients with recurrence of TMJ luxation.

Evaluation of Temporomandibular Disorders and Comorbidities in Patients with Ehler--Danlos: Clinical and Digital Findings

Objective

The objective of this study is to recognize representative cranio-cervico-mandibular features of patients with Ehler-Danlos syndrome and associated temporomandibular disorders (TMDs), to assess a targeted and integrated treatment plan.

Materials and Methods

After a diagnosis of disease, 38 individiuals with Ehler-Danlos syndrome and temporomandibular symptomatology referred were evaluated. Gnathological evaluation, according to the Diagnostic Criteria for TMDs, and radiographic imaging was performed. In addition, digital evaluation of occlusal and muscular balance, using surface electromyography of jaw muscles, was conducted. Statistical software for data analysis - STATA (StataCorp, College station, Texas, USA) - was used.

Results

Most common temporomandibular dysfunctions were arthralgia, myalgia, disc displacement with reduction and subluxation. Headache and neck pain were the most frequent comorbidities. Somatization, depression, anxiety, and obsessive-compulsive behavior were the most recurrent psychological disorders. Electromyographic analysis showed out of normal range data.

Conclusion

Early diagnosis and interception are requested to avoid injuries and repeated traumatism. Multidisciplinary treatments are available to approach all the aspects of the syndrome.

The Association between Generalized Joint Hypermobility and Temporomandibular Joint Disorders: A Systematic Review

To analyze conflicting evidence in the literature for the association between temporomandibular joint disorders (TMD) and generalized joint hypermobility (GJH), we performed a bibliographic search. The methodological quality of the 14 papers found was assessed according to 14 criteria. Papers were included in the analysis if the study population was clinically relevant, if range of motion of 2 or more joints was assessed on the left and right sides, and if cases had a TMD. Four studies fulfilled these selection criteria. Data from 3 studies, 113 cases and 95 controls, were available for analysis. Twenty-six cases and five controls were hypermobile (odds ratio, 5.4). In a sensitivity analysis, the odds ratio changed from significant to non-significant in 2 of 5 scenarios. As a result, it is not clear whether GJH is associated with TMD, and more rigorous studies are needed.

Oral and mandibular manifestations in the Ehlers-Danlos syndromes

The Ehlers-Danlos syndromes (EDS) are hereditary disorders that affect the connective tissue and collagen structures in the body. Several types of EDS have been identified. Oral and mandibular structures, which include oral soft tissue, dentition, facial and head pain, and the functioning of the temporomandibular joint (TMJ), are variably affected in the various types of EDS. These various manifestations of EDS have been noted for many years, but newer diagnostic techniques and studies are shedding additional light on the challenges faced by EDS patients in the area of oral and mandibular disorders. Further, the impact of temporomandibular disorder (TMD) on musculoskeletal dysfunction and vice versa, make this an important feature to recognize. Oral and mandibular hypermobility of the TMJ with associated consequences of EDS are noted. These features, diagnostic parameters and treatment procedures are presented. © 2017 Wiley Periodicals, Inc.

TMD and chronic pain: a current view

This review aims at presenting a current view on the physiopathologic mechanisms associated with temporomandibular disorders (TMDs). While joint pain is characterized by a well-defined inflammatory process mediated by tumor necrosis factor-α and interleukin, chronic muscle pain presents with enigmatic physiopathologic mechanisms, being considered a functional pain syndrome similar to fibromyalgia, irritable bowel syndrome, interstitial cystitis and chronic fatigue syndrome. Central sensitization is the common factor unifying these conditions, and may be influenced by the autonomic nervous system and genetic polymorphisms. Thus, TMDs symptoms should be understood as a complex response which might get worse or improve depending on an individual's adaptation.

Temporomandibular joint vibrations from totally asymptomatic subjects

OBJECTIVE

Precisely characterize the TMJ vibrations of a youthful, adult and completely asymptomatic population.

METHODS

TMJ vibrations were recorded from 237 asymptomatic subjects (163 f, 74 m) at Dayananda Sagar Institute in India. The subjects were selected, examined and informed (WMA Helsinki Declaration). TMJ vibrations were recorded bilaterally during maximal open - close. 6 parameters of the vibrations were analyzed between the left and right sides, between genders and with respect to age.

RESULTS

Mean vibration intensity was greater for females (p < 0.01) than males. A portion of the frequency spectrum < 300 Hz was also more intense for females (p < 0.022). Females 18 - 20 years old exhibited higher Peak Amplitude than 27 - 30 year olds (p < 0.025) and lower Median Frequency (p < 0.005).

CONCLUSIONS

A significant difference in TMJ vibrations was present between males and females, increased with age in females but not in males.

The association between temporomandibular disorders and joint hypermobility syndrome: a nationwide population-based study

OBJECTIVES

This study aims to investigate the risk factors of temporomandibular disorders (TMDs), including disc or non-disc-related disorders, and joint hypermobility syndrome (JHS) retrospectively and to analyze the factors by estimating the magnitude of the association between the two conditions using a nationwide population-based dataset.

MATERIALS AND METHODS

A total of 975,788 eligible patients' de-identified data were obtained from a representative database composed of one million of Taiwan's population since 2004 to 2008. All associated factors, such as gender, age, facial trauma, and psychosis, which correlated with TMDs and JHS were examined. Multiple logistic regression modeling adjusted for confounding variables to determine the odds ratio of variables that made an important contribution to TMDs and JHS.

RESULTS

For all TMDs patients, only 1.47% patients had disc-related disorders. For all JHS patients, only 3.85% patients are diagnosed with concomitant TMDs. Statistically significant association was observed between joint hypermobility and TMDs. Furthermore, the prevalence of JHS patients shows significant difference within TMD subgroups, in which 9.52% of JHS patients have disc disorders and 90.48% of JHS patients do not. All associated factors, such as gender, age, JHS, facial trauma, and psychosis, had a significant impact on the TMDs. Interestingly, patients with TMJ articular disc disorders are 6.7 times more likely to be diagnosed with JHS compared to patients without disc-related disorders.

CONCLUSIONS

Our results confirm that there is a significant positive association between TMDs and JHS, highlighting that patients with disc-related TMDs are more likely to experience JHS than patients with TMDs without disc disorders.

CLINICAL RELEVANCE

Individuals with TMD associated with JHS should be carefully evaluated by inter-disciplinary specialists as these factors may eventually have impact on the prognosis of TMDs and JHS.

Predisposition for Temporomandibular Joint Disorders: Loose Ligaments

Loose ligaments are often a predisposing factor of temporomandibular joint (TMJ) disorders. This causal factor was analyzed in 701 subjects presenting at the TMJ and Posture Center of Siena University with TMJ pain or dysfunction. Along with the conventional jaw examination, a Carter and Wilkinson test as modified by Beighton was also done. We found a correlation among the parameters of age, gender, TMJ disorder, joint pain, muscle pain, and loose ligaments.

Development and validation of the Gothenburg Trismus Questionnaire (GTQ)

OBJECTIVES

To develop and validate a comprehensive, self-administered questionnaire for patients with limited ability to open the mouth, trismus.

MATERIALS AND METHODS

We derived the Gothenburg Trismus Questionnaire (GTQ) from empirical evidence in the medical literature and interviews with medical experts as well as patients. The draft version was tested in a pilot study (n=18). Patients with a maximal incisal opening (MIO) of ⩽35mm were included. The study comprised patients with benign jaw-related conditions (n=51), patients treated for head and neck (H&N) cancer (n=78) and an age- and gender-matched control group without trismus (n=129).

RESULTS

The GTQ instrument was well accepted by the patients, with satisfactory compliance and low rates of missing items. After item reduction, due to items not being conceptually relevant and/or low factor loadings, the GTQ demonstrated high internal consistency (Cronbach's alpha 0.72-0.90), good construct validity and known-group validity.

CONCLUSION

We developed a trismus-specific self-administered questionnaire, the GTQ, that showed good psychometric properties. We suggest this questionnaire, that has clear clinical relevance, to be adopted and used in clinical practice and in research, acting as a screening tool as well as an endpoint in intervention and jaw physiotherapy/rehabilitation studies.

Biglycan and fibromodulin have essential roles in regulating chondrogenesis and extracellular matrix turnover in temporomandibular joint osteoarthritis

The temporomandibular joint is critical for jaw movements and allows for mastication, digestion of food, and speech. Temporomandibular joint osteoarthritis is a degenerative disease that is marked by permanent cartilage destruction and loss of extracellular matrix (ECM). To understand how the ECM regulates mandibular condylar chondrocyte (MCC) differentiation and function, we used a genetic mouse model of temporomandibular joint osteoarthritis that is deficient in two ECM proteins, biglycan and fibromodulin (Bgn(-/0)Fmod(-/-)). Given the unavailability of cell lines, we first isolated primary MCCs and found that they were phenotypically unique from hyaline articular chondrocytes isolated from the knee joint. Using Bgn(-/0) Fmod(-/-) MCCs, we discovered the early basis for temporomandibular joint osteoarthritis arises from abnormal and accelerated chondrogenesis. Transforming growth factor (TGF)-beta1 is a growth factor that is critical for chondrogenesis and binds to both biglycan and fibromodulin. Our studies revealed the sequestration of TGF-beta1 was decreased within the ECM of Bgn(-/0) Fmod(-/-) MCCs, leading to overactive TGF-beta1 signal transduction. Using an explant culture system, we found that overactive TGF-beta1 signals induced chondrogenesis and ECM turnover in this model. We demonstrated for the first time a comprehensive study revealing the importance of the ECM in maintaining the mandibular condylar cartilage integrity and identified biglycan and fibromodulin as novel key players in regulating chondrogenesis and ECM turnover during temoporomandibular joint osteoarthritis pathology.

Joint hypermobility and disk displacement confirmed by magnetic resonance imaging: a study of women with temporomandibular disorders

OBJECTIVE

The objective of this study was to test whether or not there is an association between generalized joint hypermobility (measured using the Beighton score) and temporomandibular joint disk displacement in women who had sought medical attention for temporomandibular disorders (TMD).

STUDY DESIGN

We studied 66 women who were attending the clinic for TMD. The patients were examined for joint hypermobility, and Beighton scores were calculated. When it was suspected that a patient suffered arthropathic complaints, magnetic resonance imaging of both temporomandibular joints was performed with the mouth closed and at maximal opening. The Pearson chi-squared test was used to test for an association between generalized joint hypermobility and disk displacement.

RESULTS

We were unable to confirm the existence of an association between generalized joint hypermobility and temporomandibular joint disk displacement in women (chi(2) = 1.523; P = .02).

CONCLUSION

Generalized joint hypermobility may be a factor related to TMD, but we did not find an association between generalized joint hypermobility and anterior disk displacement in women.

Muscle disorders and dentition-related aspects in temporomandibular disorders: controversies in the most commonly used treatment modalities

This review explores the aetiology of temporomandibular disorders and discusses the controversies in variable treatment modalities.Pathologies of the temporomandibular joint (TMJ) and its' associated muscles of mastication are jointly termed temporomandibular disorders (TMDs).TMDs present with a variety of symptoms which include pain in the joint and its surrounding area, jaw clicking, limited jaw opening and headaches. It is mainly reported by middle aged females who tend to recognize the symptoms more readily than males and therefore more commonly seek professional help.Several aetiological factors have been acknowledged including local trauma, bruxism, malocclusion, stress and psychiatric illnesses. The Research Diagnostic Criteria of the Temporomandibular Disorders (RDC/TMD) is advanced to other criteria as it takes into consideration the socio-psychological status of the patient.Several treatment modalities have been recommended including homecare practices, splint therapy, occlusal adjustment, analgesics and the use of psychotropic medication; as well as surgery, supplementary therapy and cognitive behavioural therapy. Although splint therapy and occlusal adjustment have been extensively used, there is no evidence to suggest that they can be curative; a number of evidence-based trials have concluded that these appliances should not be suggested as part of the routine care.Surgery, except in very rare cases, is discouraged since it is the most invasive alternative; recent studies have shown healthier outcome with cognitive behavioural therapy.

The many faces of the genetics contribution to temporomandibular joint disorder

OBJECTIVES

Review the literature on candidate genes for temporomandibular joint disorder (TMD). Setting and Sample Population - Literature review.

MATERIALS AND METHODS

Two basic approaches were used to obtain literature in any language regarding genes and TMD. First, Medline, Embase, and Science Citation Index databases were searched using the keywords 'temporomandibular joint disorder' and 'temporomandibular joint dysfunction' for studies published from 1966 to 2007. Then, the references list of the studies obtained in the database was also considered.

RESULTS

Candidate genes for TMD include genes for individual variations in pain perception, gender and ethnicity, proinflammatory cytokines, female hormones, breakdown of extracellular matrix, and syndromic forms of TMD.

CONCLUSION

Most of the studies on genetic variation contributing to TMD are approaching the disease mainly from an immune-inflammatory perspective. Recent investigations of the genetic variables which may predict identifiable levels of pain perception may uncover new approaches to our traditional treatment modalities for the chronic pain patient.

Developmental Coordination Disorder and Joint Hypermobility Syndrome--overlapping disorders? Implications for research and clinical practice

BACKGROUND

Joint Hypermobility Syndrome (JHS) and Developmental Coordination Disorder (DCD) are two childhood disorders usually identified separately. DCD is a heterogeneous condition with little known of the underlying aetiology of the disorder. This paper examines the potential overlap between DCD and JHS and examines children with DCD for symptoms which may be consistent with a diagnosis of JHS. Implications for research and clinical practice are considered.

METHODS

A questionnaire covering a range of symptoms consistent with a diagnosis of JHS and related autonomic nervous systemic symptoms was completed by parents from 27 children with DCD and compared with responses from parents of 27 typically developing children.

RESULTS

Children with DCD showed a significant difference from the group of typically developing children on questions regarding hypermobility, pain and autonomic nervous system symptoms, typifying JHS.

CONCLUSIONS

This study has shown a similarity in symptoms seen in some DCD children to those with a diagnosis of JHS. In addition, children are also presenting with multi-system symptomatology including those involving the autonomic nervous system. This study reinforces other recent work showing the reverse pattern of JHS children showing similar functional similarities to DCD children. This has implications for future research in DCD in order to understand the underlying aetiology of this complex disorder. In addition, it is important for clinicians to be aware of these findings in order to provide appropriate and tailored support and treatment for children presenting with differing patterns of co-ordination difficulties. Children with DCD and JHS may require appropriate podiatry as well as recognition of their symptoms of pain and how this may affect participation in physical activity.

The role of systemic hypermobility and condylar hypermobility in temporomandibular joint dysfunction syndrome

OBJECTIVE

To evaluate the risk of temporomandibular joint dysfunction (TMD), when both systemic joint hypermobility (SJH) and localized condylar hypermobility (LCH) exist.

MATERIALS AND METHODS

Sixty-four consecutive outpatients with temporomandibular joint clicking or pain, and 77 sex- and age-matched control subjects, were recruited in the study. LCH was diagnosed when condylar subluxation was present, and SJL was diagnosed by using Beighton's method. The frequency of symptoms, mean mouth opening, and the frequency of subjects with SJL and LCH were the main outcome measures.

RESULTS

Out of the 64 patients, 16 patients were suffering from pain, 20 patients from joint-clicking and 28 patients from both. Both SJH and LCH were more frequently observed in those patients with TMD than in control subjects. The risk of TMD was higher if LCH and SJH existed jointly.

CONCLUSION

Both systemic and localized hypermobility may have a role in the etiology of TMD.

MRI findings concerning the lateral pterygoid muscle in patients with symptomatic TMJ hypermobility

Clinical studies have shown a close association between temporomandibular joint hypermobility (TMJH) and temporomandibular disorders (TMD). While pathological change of the lateral pterygoid muscle (LPM) is one of the most emphasized in studies of TMD, there have been no detailed clinical reports of the LPM studies using magnetic resonance imaging (MRI) in TMJH. This study investigates structural and pathological alterations involving the LPM in patients with TMJH using MRI. A retrospective analysis was made of high-field MRI images from 98 patients with TMJH. LPMs of 143 joints were analyzed. In 110 joints (77%), hypertrophy, atrophy, and contracture were found in the superior belly and/or the inferior belly of the LPM. Pathological changes were more frequently found in the superior rather than the inferior belly of the LPM. In the cases with abnormalities in both bellies of the LPM, hypertrophy of the inferior belly was usually found combined with other changes of the SBLPM. The results of this study indicated that the pathological changes of the LPM or MRI are not infrequent in patients with symptomatic TMJH.

Identifying a neurobiologic basis for drug therapy in TMDs

Emerging results from clinical and basic research indicate that persistent pain results in changes in the central nervous system. These changes may help explain chronic orofacial pain and lead to new therapies. The authors review data that support the use of tricyclic antidepressants for neurogenic or atypical pain, and benzodiazepines for musculoskeletal pain. Dentists must weigh the benefits of the chronic administration of a drug for the management of temporomandibular disorders against the equivocal scientific support for the use of many drug classes and the potential for serious toxicity with prolonged administration.

Generalized joint hypermobility as a factor in clicking of the temporomandibular joint

Twenty-six patients with clicking or locking of the temporomandibular joint (TMJ) and 28 age- and sex-matched controls were assessed for generalized joint hypermobility by BEIGHTON's method. Function of the masticatory apparatus was measured with FRICTON's Craniomandibular Index. The TMJ patients had significantly higher joint mobility scores, but within the patient group there was no correlation between either the dysfunction or palpation scores and the hypermobility scores. The findings are interpreted as supporting multiple causes of TMJ internal derangement, one of which is a systemic joint factor.

The relationship between temporomandibular joint mobility and peripheral joint mobility reconsidered

The purpose of this paper was to study the relationship between temporomandibular joint (TMJ) mobility and mobility of joints and to study the general character of joint mobility in 83 subjects, 55 females and 28 males (mean age 26.7, range 13-46 years). The subjects were recruited from the Department of Oral and Maxillofacial Surgery of the University Hospital of Groningen. All participants had a good general health and did not present anamnestically, clinically or radiographically TMJ disorders. Of these subjects, angular displacement of the mandible relative to the cranium during maximal mouth opening (AMO) was measured. Furthermore, the maximal range of motion of passive digit five hyperextension, passive thumb apposition to the wrist, active elbow and knee hyperextension, active ankle dorsal flexion and trunk flexion were measured. All measurements were performed bilaterally, except trunk flexion. Calculation of product moment correlations (Pearson) revealed a weak relationship between AMO and mobility of right digit five and elbows for the total group and between AMO and mobility of both digits five and elbows for women. The correlations were never stronger than 0.4. Multiple regression revealed that only 25.9% of the total variance of AMO could be explained by mobility of peripheral joints, age and sex. Calculation of product moment correlations between mobility of peripheral joints, trunk flexion and age revealed weak correlations between the different joints, with the exception of paired joints. Principal component analysis revealed a weak general character of joint mobility.(ABSTRACT TRUNCATED AT 250 WORDS)

Joint mobility measurements: reliability of a standardized method

Assessment of hypermobility and hypomobility is frequently performed visually with all its limitations. In this study, a standardized joint mobility measurement method is suggested, and its reliability is tested. The maximal range of motion of passive digit five hyperextension, passive thumb apposition to the wrist, active elbow and knee hyperextension, active ankle dorsal flexion and trunk flexion was measured in 30 healthy subjects. All measurements were performed bilaterally, except for trunk flexion. Three experienced observers performed the measurements according to a rigidly standardized protocol, using appropriate goniometers and rules. During one measurement session each observer measured each subject. Two consecutive measurement sessions were organized. Analysis of variance, with subject and time as explaining variables, was performed on the data obtained. The inter-observer variability ranged from 1.42 degrees (left knee hyperextension) to 4.05 mm (right thumb apposition) in the first measurement session and from 1.35 degrees (left knee hyperextension) to 4.58 degrees (right digit five hyperextension) in the second measurement session. The intra-observer variability ranged for observer A from 0.75 degree (left knee hyperextension) to 3.67 mm (left thumb apposition), and from 0.93 degree (left knee hyperextension) to 3.88 degrees (left digit five hyperextension) for observer B. Observer C ranged from 0.71 degree (left knee hyperextension) to 4.01 mm (right thumb apposition). Based on the results of this study, the authors conclude that joint mobility can be measured reliably and accurately with the presented simple tools.(ABSTRACT TRUNCATED AT 250 WORDS)