Characteristics of a jaw reflex in humans with temporomandibular disorders: a preliminary report

Electromyography was used to compare characteristics of an inhibitory jaw reflex in 10 temporomandibular disorder patients and 10 age- and sex-matched healthy controls. The methodology was novel in that the reflex was that evoked in the active masseter muscle, by electrical stimulation of perioral skin. This response has advantages over those previously studied as it avoids problems associated with stimulating in the moist intra-oral environment and it is monophasic, thus permitting easy quantification. The results have shown that (i) with the stimulation parameters employed, the reflex was present in all 10 control subjects, but in only eight of 10 temporomandibular disorder patients. (ii) When stimulation intensities were expressed as multiples of sensory threshold, there was no significant difference in the minimum level of stimulation required to evoke the reflex between the groups, although there was a trend for the patients with temporomandibular disorders to require higher intensities. (iii) Comparison of data from subjects giving responses at the same stimulus intensity (6 x sensory threshold: seven temporomandibular disorder patients, eight controls), showed no significant differences in the latencies or magnitudes of the reflex between the groups. However, the overall duration of the reflex was significantly shorter for the patients with temporomandibular disorders, with the reflex finishing significantly earlier. Thus even within the limitations of this study, it appears that an inhibitory jaw reflex evoked from stimulation around the mouth, may be weaker in temporomandibular disorder patients. This conclusion is consistent with previous studies on more complex jaw reflexes evoked by intra-oral stimuli.     

General practice dentists'' knowledge of temporomandibular disorders in children and adolescents

Aim: The aim of the study was to map general practice dentists' (GPDs) knowledge of temporomandibular disorders (TMD) in children and adolescents. Materials and methods: A questionnaire was mailed to 286 Swedish dentists in the Public Dental Service and 17 TMD specialists with documented research experience. The questionnaire contained 37 statements on aetiology, diagnostics, classification, chronic pain and pain behaviour, treatment, and prognosis. Each statement was judged on a 0-10 point scale with the endpoint definitions agree or disagree. Results: The overall response rate to the questionnaire was 87%. In 28 of all 37 statements, the TMD specialists endorsed a consensus, i.e. >75% of the specialists had the same opinion about the statement. TMD specialists differed most in opinion in the domain diagnostics and classification. In 65% of the statements, differences in knowledge between GPDs and TMD specialists were non-significant. The greatest number of significant between-group differences was found in the domain treatment and prognosis. Most of these statements were related to morphological factors. Conclusion: There is a high degree of consensus in TMD knowledge amongst the TMD specialists and a high degree of agreement in knowledge between GPDs and TMD specialists. In some areas, however, TMD specialists still need to reach a consensus which is founded on evidence-based TMD knowledge in children and adolescents and that can be used in undergraduate teaching. It is therefore important to develop and strengthen the undergraduate dental teaching in TMD and orofacial pain.     

Study on self-assessment regarding knowledge of temporomandibular disorders in children/adolescents by Swedish and Saudi Arabian dentists

Abstract

Objective. To estimate the degree of self-assessed knowledge among dentists in Sweden and Saudi Arabia regarding temporomandibular disorders (TMD) in children and adolescents using a summative form of assessment and further to investigate the possible factors that may influence the self-assessed knowledge. Materials and methods. A questionnaire survey covering four domains (Etiology; Diagnosis and classification; Chronic pain and pain behavior; Treatment and prognosis) regarding TMD knowledge was used. Out of 250 questionnaires (125 in each country) a total of 65 (52%) were returned in Sweden and 104 (83%) in Saudi Arabia. Results. Self-assessed individual knowledge was significantly associated to the level of actual knowledge among the Swedish groups in the domains Etiology; Diagnosis and classification and Treatment and prognosis (p < 0.05). However, in the Saudi Arabian groups a corresponding significant association was only found in the domain Diagnosis and classification (p < 0.05). Conclusions. This study showed that there is a difference in the accuracy of self-assessment of own knowledge between the dentists in Sweden and Saudi Arabia. The Swedish dentists have a better ability to assess their level of knowledge compared to Saudi Arabian dentists regarding TMD in children and adolescents. This difference could be related to several factors such as motivation, positive feedback, reflection, psychomotor, and interpersonal skills, which all are more dominant in the Swedish educational tradition.     

The effect of the gonial angle, ramus length, age and gender on the temporomandibular opening index

summary   Linear mouth opening is often used to assess the limitation of mandibular movement. However, this has a number of limitations. It is dependent on variables such as age, gender and ramus length. A new measure of movement has been developed previously, called the temporomandibular opening index (TOI). Forty-two subjects who did not exhibit signs and symptoms of temporomandibular disorder (TMD) were recruited to this study. The relationship of age, gender, gonial angle, ramus length and the TOI was studied. Linear regression analysis showed that the TOI was not dependent on gender ( P  > 0·644), gonial angle ( P  > 0·327), ramus length ( P  > 0·248) and age ( P  > 0·690). The index may therefore be a better measure of mandibular movement.     

528例儿童颞下颌关节紊乱病的回顾性研究

目的:探讨儿童TMD患者528例的性别、年龄对TMD症状体征的发生情况和CBCT表现的影响.方法:采用回顾性研究方法,收集6-14岁TMD患者,分别按照性别及年龄(6-8岁低年级、9-11岁中年级、12-14岁高年级)分组,对疼痛、弹响或杂音、开口型异常及开口受限等症状体征和CBCT影像学表现进行归纳分析.结果:男性1...     

Symptoms and signs of temporomandibular disorders and oral parafunctions among Saudi children

This study aimed to record the prevalence of signs and symptoms of temporomandibular disorders (TMD) and oral parafunctions among Saudi children. A questionnaire and a clinical examination of signs and symptoms of TMD were performed on 1940 stratified randomly selected schoolchildren. The sample was divided into three groups, 505 with primary, 737 with mixed and 734 with permanent dentition. The prevalence of TMD signs was found to be 20.7% and the most common sign of TMD was joint sounds (11.8%). The second most common sign was restricted mouth opening (5.3%). Muscle and temporomandibular joint (TMJ) pain as well as deviation upon jaw opening appeared infrequently. TMJ sounds were significantly increasing with age (P < 0.05). TMD symptoms as reported by the parents were evident in 24.2% of the returned questionnaires (1113). The most common symptoms were headache (13.6%) and pain on chewing (11.1%). The incidence of headache was found to be significantly increasing from primary to permanent dentition (P < 0.01). No sex difference in the prevalence of any symptom was reported. Nail biting was the most common oral parafunction (27.7%) while bruxism was the least common (8.4%). All parafunctions except bruxism were significantly related to age. Cheek biting and thumb sucking were reported more in females than in males. The importance of a screening examination for symptoms and signs of TMD should not be overlooked in the clinical assessment of the pediatric patient.     

下颌运动轨迹分析在颞下颌关节紊乱病诊疗中的应用及展望

近年来,颞下颌关节紊乱综合征(temporomandibular disorder,TMD)患病率越来越高,且病因复杂.下颌运动轨迹观测能够针对颞下颌关节(temporomandibular joint,TMJ)的运动能力及协调性进行诊断分析,广泛应用于口腔正畸、修复及外科治疗过程中,对TMD的诊断分析及疗效评定具有重...     

Prevalence of bruxism and temporomandibular disorders among orphans in southeast Uganda: A gender and age comparison

Objectives: The aims of the current study were: (1) to assess the prevalence of oral habits, bruxism, and temporomandibular disorders (TMDs) among children living in Uganda; (2) to establish whether parafunctional activities are associated with TMDs; and (3) to examine the possible impact of gender and age on the prevalence of bruxism, oral habits, and TMDs.

Methods: This study included 153 children aged 6–17 years. The study consisted of a questionnaire and a clinical examination.

Results: TMDs were moderately prevalent (35%). Parafunctional habits were performed by 93% of the participants. When performed extensively, they were significantly related to myalgia. No gender or age significant differences were found.

Conclusions: 1. Only extensive masticatory parafunctional oral activity is significantly related to myalgia. 2. Gender and age had no impact on the prevalence of bruxism, oral habits, or TMDs. 3. Sleep and awake bruxism were not related to anamnestic symptoms or clinical findings in TMD.     

Management of temporomandibular joint arthritis in children and adolescents: An introduction for orthodontists

Juvenile idiopathic arthritis (JIA) is the most common inflammatory rheumatic disease of childhood. JIA can affect any joint and the temporomandibular joint (TMJ) is one of the joints most frequently involved. TMJ arthritis impacts mandibular growth and development and can result in skeletal deformity (convex profile and facial asymmetry), and malocclusion. Furthermore, when TMJs are affected, patients may present with pain at joint and masticatory muscles and dysfunction with crepitus and limited jaw movement. This review aims to describe the role of orthodontists in the management of patients with JIA and TMJ involvement. This article is an overview of evidence for the diagnosis and treatment of patients with JIA and TMJ involvement. Screening for the orofacial manifestation of JIA is important for orthodontists to identify TMJ involvement and related dentofacial deformity. The treatment protocol of JIA with TMJ involvement requires an interdisciplinary collaboration including orthopaedic/orthodontic treatment and surgical interventions for the management of growth disturbances. Orthodontists are also involved in the management of orofacial signs and symptoms; behavioural therapy, physiotherapy and occlusal splints are the suggested treatments. Patients with TMJ arthritis require specific expertise from an interdisciplinary team with members knowledgeable in JIA care. Since disorders of mandibular growth often appear during childhood, the orthodontist could be the first clinician to see the patient and can play a crucial role in the diagnosis and management of JIA patients with TMJ involvement.     

Professional knowledge among Swedish and Saudi healthcare practitioners regarding oro‐facial pain in children and adolescents

Oro‐facial pain (OFP) and temporomandibular disorders (TMD) in children and adolescents are a growing problem. To meet patients’ healthcare needs, professionals must perform their work intuitively and with quality. Therefore, a high degree of professional knowledge is necessary. To investigate the professional knowledge regarding OFP/TMD in children and adolescents among Swedish and Saudi Arabian dental and medical specialists compared with Swedish OFP specialists. One questionnaire including the four domains Chronic pain and behaviour; Aetiology; Diagnosis and classification; Treatment and prognosis was distributed to 383 potential participants, that is physicians and dentists in Sweden and Saudi Arabia. The Swedish OFP/TMD specialists were used as a reference group. The response rates from Sweden and Saudi Arabia were 49% and 86%, respectively. The degree of agreement was highest in the domain Chronic pain and behaviour, especially for the Swedish groups. Regarding the other three domains, the agreement was modest to poor. In general, Swedish groups showed a higher agreement with Swedish OFP/TMD specialists than Saudi Arabian groups. This study shows that professional knowledge regarding OFP/TMD in children and adolescents is limited among Swedish and Saudi Arabian dental and medical professionals compared to Swedish OFP/TMD specialists. In Swedish groups, the professional knowledge is more accurate than in the corresponding Saudi Arabian. With these results in mind, and the frequent prevalence of OFP/TMD in children and adolescents, one can draw the conclusion that there is a need for modern medical education regarding OFP/TMD among both physicians and dentists, especially in Saudi Arabia.     

Association between posterior crossbite and/or deep bite and temporomandibular disorders among Palestinian adolescents: A sex comparison

ABSTRACT

Objective: To assess the prevalence of temporomandibular disorders (TMDs) and posterior crossbite and/or deep bite and any possible association between them.

Methods: One thousand-nineteen adolescents responded to a questionnaire regarding oral habits and TMD symptoms. Afterwards, they were diagnosed according to the Axis I of the DC/TMD and underwent a dental examination. The chi-square test was used for statistical analysis.

Results: A significant association was found between posterior crossbite and some TMD diagnosis, but no association was found between deep bite and TMD, nor between occlusal diagnosis and bruxism. TMDs were more prevalent in girls. There was a significant sex difference (more among females) in the prevalence of painful TMDs.

Conclusion: Posterior crossbite in the adolescent population analyzed may be related to TMDs, in contrary to deep-bite. The presence of posterior crossbite may have different impact on TMD findings between the sexes.     

Timing of arthrocentesis in the management of temporomandibular disorders: an integrative review and meta-analysis

The aim of this study was to assess the best timing to perform arthrocentesis in the management of temporomandibular disorders with regard to conservative treatment. A systematic search based on PRISMA guidelines, including a computer search with specific keywords, reference list search, and manual search was performed. Relevant articles were selected after three search rounds for final review based on six predefined inclusion criteria, followed by a round of critical appraisal. Eleven publications, including eight randomized controlled trials and three prospective clinical studies, were included in the review. The studies were divided into three groups based on the timing of arthrocentesis: (1) arthrocentesis as the initial treatment; (2) early arthrocentesis; and (3) late arthrocentesis. Meta-analysis was carried out to compare the efficacy of improvement in mouth opening and pain reduction in the three groups. All three groups showed improvement in mouth opening and pain reduction, with forest plots suggesting that arthrocentesis performed within 3 months of conservative treatment might produce beneficial results. We conclude that there is a knowledge gap in the current literature regarding the preferable timing to perform arthrocentesis in the management of temporomandibular disorders, and more high-quality randomized controlled trials are required to shed light on this subject.     

Mandibular condyle lesions, jaw movements, and occlusal status in 15-year-old children with juvenile rheumatoid arthritis

Abstract – The purpose was to determine the number and severity of lesions in the temporomandibular area and their association with occlusal status and mandibular movements, in 15-yr-old children afflicted with juvenile rheumatoid arthritis (JRA). The series comprised 121 JRA children, 78 girls and 43 boys, and a control group of 104 schoolchildren, 70 girls and 34 boys, taken for clinical examination. Of the JRA children, 55% had roentgenologically detectable lesions in the TMJ area. Lesions were found in 60% of the girls and in 42% of the boys, the ratio thus being 3:2. The largest group had grave lesions (48%), the second largest displayed flattening of the condyle (43%) and the smallest a flattened condyle with a minor lesion (9%). There were more bilateral lesions in the children with the severest lesions. Tendencies for Class II malocclusion, small vertical overbite and open bite were visible in the JRA children. Reduced maximal opening capacity, maximal protrusion, lateral movements of the mandible and pain in the TMJ area proved to be reliable signs predicting temporomandibular joint involvement in JRA children. Maximal mouth opening capacity was significantly restricted in the patients showing condylar lesions as compared with patients having no lesions or with controls. JRA children should be divided according to sex and the severity of the lesions. The JRA children without TMJ lesions had normal values for mandibular movements and were thus comparable to healthy children.     

Bruxism, oral parafunctions, anamnestic and clinical findings of temporomandibular disorders in children

Summary The reported prevalence of temporomandibular disorders (TMD) present during childhood and adolescence ranges between 7% and 68%. The range of the reported prevalence of sleep bruxism in children is also wide. The purpose of the current study was threefold: (i) determine the prevalence of oral parafunctions, sleep bruxism and of anamnestic and clinical findings of TMD among Israeli children with primary or mixed dentition; (ii) to establish whether the parafunctional activities are associated with anamnestic and clinical findings of TMD in this population and (iii) to examine the possible impact of stressful life events on the prevalence of bruxism, oral parafunctions, and anamnestic and clinical findings of TMD in children. A total of 244 children (183 girls and 61 boys) aged 5–12 years were included in the study. Each participant underwent a full TMD examination. Parents, in collaboration with their children, completed a questionnaire on TMD symptoms, oral parafunctions and stressful life events in their children’s life. Most participants (78·8%) reported at least one oral habit. Of these, only ‘jaw play’ was associated with TMD anamnestic and clinical findings. Stressful life events were associated only with the performance of multiple oral habits. These findings indicate that the performance of oral parafunctions is commonplace during childhood, with younger children exhibiting fewer oral parafunctions than adolescents. Stressful life events are related with an increase in the performance of multiple oral parafunctions in children but the later are not necessarily associated with anamnestic and clinical findings of TMD in the paediatric population.     

Prevalence and risk factors of sleep bruxism and wake-time tooth clenching in a 7- to 17-yr-old population

Carra MC, Huynh N, Morton P, Rompré PH, Papadakis A, Remise C, Lavigne GJ. Prevalence and risk factors of sleep bruxism and wake‐time tooth clenching in a 7‐ to 17‐yr‐old population.
Eur J Oral Sci 2011; 119: 386–394. © 2011 Eur J Oral Sci Sleep‐related bruxism (SB) and wake‐time tooth clenching (TC) have been associated with temporomandibular disorders (TMDs), headache, and sleep and behavioral complaints. This study aimed to assess the prevalence and risk factors of these signs and symptoms in a 7‐ to 17‐yr‐old population (n = 604) seeking orthodontic treatment. Data were collected by questionnaire and by a clinical examination assessing craniofacial morphology and dental status. Sleep‐related bruxism was reported by 15% of the population and TC was reported by 12.4%. The SB group (n = 58) was mainly composed of children (67.3% were ≤12 yr of age) and the TC group (n = 42) was mainly composed of adolescents (78.6% were ≥13 yr of age). The craniofacial morphology of over 60% of SB subjects was dental class II and 28.1% were a brachyfacial type. Compared with controls (n = 220), SB subjects were more at risk of experiencing jaw muscle fatigue [adjusted OR (AOR) = 10.5], headache (AOR = 4.3), and loud breathing during sleep (AOR = 3.1). Compared with controls, TC subjects reported more temporomandibular joint clicking (AOR = 5), jaw muscle fatigue (AOR = 13.5), and several sleep and behavioral complaints. Sleep‐ and wake‐time parafunctions are frequently associated with signs and symptoms suggestive of TMDs, and with sleep and behavioral problems. Their clinical assessment during the planning of orthodontic treatment is recommended.