Chewing ability as a parameter for evaluating the disability of patients with temporomandibular disorders

Restoration of chewing ability is an important aspect of the treatment for temporomandibular disorders (TMDs). However, too little attention has been paid to it. We have used a questionnaire to evaluate and score the chewing ability of TMD patients. The questionnaire includes 19 kinds of food and a chewing task. The patient was asked if she/he experiences difficulty in enjoying eating. The aim of this study was to evaluate correlations between score of chewing ability (SCA) and other symptoms/signs of TMD. Four hundred and seventy-three consecutive TMD patients were evaluated for SCA and other symptoms/signs including temporomandibular joint (TMJ) pain, TMJ and muscle tenderness, TMJ noise (clicking and crepitus), and maximum mouth opening. The relationship between SCA and other symptoms/signs were analysed by multiple regression analysis. Score of chewing ability correlated significantly with TMJ pain and mouth opening capacity but not with TMJ noise and muscle tenderness. Age was a background factor but sex was not. The result of this study suggests that SCA correlated with dysfunction of the TMD patients. This method could be used to evaluate the ability of chewing in assessment of TMD.     

Prevalence of temporomandibular disorder pain,jaw noises and oral behaviours in an adult Italian population sample

To evaluate the prevalence of temporomandibular disorder pain (TMD‐pain), temporomandibular joint (TMJ) noises, oral behaviours in an Italian adult population sample, their possible association with gender, oral behaviours, self‐reported facial trauma and orthodontic treatment. Subjects older than 18 years were recruited from general population in public spaces during their daily life. A specific questionnaire was developed to collect data on TMD‐pain, TMJ noises, oral behaviours, orthodontic treatment and facial trauma. A total of 4299 subjects were included in the study. The most common symptom in the sample was TMJ clicking (30.7%), followed by TMD‐pain (16.3%) and TMJ crepitus (10.3%). Oral behaviours were reported in 29% of the sample; 43.6% of the sample reported a previous or ongoing orthodontic treatment. TMD‐pain and TMJ clicking were significantly associated to gender, oral behaviours and a positive history of previous facial trauma. Crepitus was significantly associated to oral behaviours, facial trauma and higher age. Ongoing orthodontic treatment was significantly associated to TMD‐pain and TMJ sounds. In a general Italian adult population sample, TMD‐pain is associated to female gender and is less prevalent than TMJ clicking. TMDs are associated to trauma and oral behaviours.     

下颌骨矢状劈开后退术对颞下颌关节的影响

目的:评价下颌骨矢状劈开后退术对颞下颌关节(TMJ)的影响.方法:研究我院50 例术前有颞下颌关节病(TMD),且行下颌骨矢状劈开后退术的患者,从关节压痛、弹响、张口度、张口型等方面量化评估术前、术后颞下颌关节症状变化情况.结果:从关节压痛、弹响、张口度、张口型等各方面评估均显示术后颞下颌关节症状评分均显著低于术前(P<0.05).结论:对于术前有颞下颌关节病的患者,行下颌骨矢状劈开后退术可以有效改善颞下颌关节症状.     

The craniocervical connection: a retrospective analysis of 300 whiplash patients with cervical and temporomandibular disorders

Because the concept of whiplash as a causative factor for temporomandibular disorders (TMD) is highly controversial, we decided to do a retrospective analysis of patients treated in our office who had sustained whiplash injuries and were treated for cervical and temporomandibular disorders. The records of 300 patients with TMD preceded by a motor vehicle accident were examined retrospectively. The most common presenting symptoms, in order, were: jaw pain, neck pain, post-traumatic headache, jaw fatigue, and severe temporomandibular joint (TMJ) clicking. The most common TMD diagnoses were: masseter trigger points, closing jaw muscle hyperactivity, TMJ synovitis, opening jaw muscle hyperactivity, and advanced TMJ disk derangement. Based primarily on the physical examination, we concluded that the TMJ and surrounding musculature should be examined similarly to other joints, with no preconceived notion that TMD pathology after whiplash is unlikely.     

Magnetic resonance imaging findings of internal derangement in temporomandibular joints without a clinical diagnosis of temporomandibular disorder

The purpose of this study was to assess the prevalences of magnetic resonance (MR) imaging findings of internal derangement (ID) in temporomandibular joints (TMJs) without a specific clinical diagnosis of temporomandibular disorder (TMD), and to investigate whether in this TMJ group the variable of pain may be linked to MR imaging findings of ID. The study comprised 109 patients, who were assigned a clinical uni- or bilateral TMJ-related diagnosis of 'absence of TMD'. Bilateral sagittal and coronal MR images were obtained subsequently to establish the prevalence of TMJ ID. An MR imaging diagnosis of ID was found in 99 (55.9%) of the 177 TMJs investigated. About 30.3% of the closed mouth-related TMJ positions characterized by disc displacement presented with anterior disc displacement, while 27.3% had anterolateral and 25.3% anteromedial disc displacement. Analysis of the data revealed the presence of TMJ pain to be associated with significantly more MR imaging diagnoses of disc displacement without reduction than disc displacement with reduction (P < 0.05), while there was no significant difference in the prevalences of ID and those of absence of ID (P > 0.05). Using chi-square analysis, no significant relationship was found between the presence of TMJ pain and the MR imaging diagnosis of TMJ ID (P=0.93). Use of the kappa statistical test indicated poor diagnostic agreement between the presence of TMJ pain and the MR imaging diagnosis of ID (kappa=0.01). The results suggest TMJs with a clinical diagnosis of 'absence of TMD' to be associated with a high rate of IDs, while in these instances the clinical variable of TMJ pain may have no effect on prevalences of MR imaging diagnoses TMJ ID. The data confirm the aspect of clinical diagnostic criteria as an unreliable instrument in predicting MR imaging diagnoses of TMJ ID.     

Oral parafunctions and association with symptoms of temporomandibular disorders in Japanese university students

We examined whether oral parafunctions are associated with symptoms of temporomandibular disorders (TMD) in 3557 Japanese university students, aged between 18 and 26 years. Participants completed a questionnaire regarding various oral parafunctions and subjective symptoms related to TMD, and underwent a dental examination. The prevalence of temporomandibular joint (TMJ) noise, TMJ pain and impaired mouth opening was 41.7, 16.0 and 16.3%, respectively. The most prevalent parafunction was sleeping on one side (60.2%), followed by supporting the jaw by leaning on the palm of the hand (44.8%). Mean age, decayed, missing and filled teeth, and number of teeth were not significantly different between TMD positive and negative groups according to unpaired t-test. The chi-squared test revealed that the ratio of females was significantly higher among students with TMD than without TMD. Multiple logistic regression models adjusted for age and gender demonstrated that chewing on one side caused an increased risk of TMJ noise [odds ratio (OR) = 1.52, P < 0.001], TMJ pain (OR = 1.54, P < 0.001), and impaired mouth opening (OR = 2.00, P < 0.001). Tooth clenching also increased the risk of TMJ noise (OR = 1.86, P < 0.001), TMJ pain (OR = 1.79, P = 0.001) and impaired mouth opening (OR = 1.88, P < 0.001). Further prospective cohort studies, including other potential risk factors, are required to clarify these relationships.     

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.     

颞下颌关节紊乱病症状、体征与患者生活质量的关系

目的定量分析颞下颌关节紊乱病（temporomandibulardisorders,TMD）症状、体征与患者生活质量的关系。方法连续选择初次就诊的TMD患者492例,自制“生活质量视觉模拟尺评估表”,计分评价TMD患者生活质量受影响程度。结果TMD对生活质量的影响主要表现在咀嚼、日常生活和情绪方面;单纯关节弹响对生活质量的影响最小;关节绞锁对生活质量的影响显著大于单纯关节弹响;重度和中度的疼痛、开口受限对生活质量的影响显著大于轻度的疼痛、开口受限。结论临床治疗应考虑TMD患者主诉症状对生活质量的影响程度。     

Relationship between temporomandibular joint pain and magnetic resonance imaging findings of internal derangement

In terms of clinical decision-making in instances of temporomandibular disorders (TMD) and orofacial pain, there is controversy in the literature over the diagnostic significance of the temporomandibular joint (TMJ)-related variable disk-condyle relationship (DCR). The purpose of this study was to investigate whether in patients with TMJ-related pain, the variable of TMJ pain may be linked to magnetic resonance (MR) imaging findings of internal derangement (ID). The study comprised 163 consecutive TMJ pain patients. Criteria for including a patient were report of orofacial pain referred to the TMJ, and the presence of uni- or bilateral TMJ pain during palpation, during function, and/or during unassisted or assisted mandibular opening. Bilateral sagittal and coronal MR images were obtained to establish the prevalence of TMJ ID types. Analysis of the data revealed the presence of TMJ pain to be associated with significantly more MR imaging diagnoses of ID than an absence of ID (P<0.001), and disk displacement without reduction than disk displacement with reduction (P<0.001). Using chi-square analysis, the results showed a significant relationship between the presence of TMJ-related pain and the MR imaging diagnosis of TMJ ID (P=0.001), and TMJ ID type (P=0.000). Use of the Kappa statistical test indicated poor diagnostic agreement between the presence of TMJ pain and the MR imaging diagnosis of ID (K=0.16). The results suggest that the clinical variable of TMJ pain may have a significant effect on the prevalences of MR imaging diagnoses of TMJ ID. The data confirm the biological concept of DCR as a diagnostic approach in patients with signs and symptoms of TMJ-related pain.     

Predictors of signs and symptoms of temporomandibular disorders: a 20-year follow-up study from childhood to adulthood

The aim of this study was to find possible predictors of signs and symptoms of temporomandibular disorders (TMD) in a long-term perspective. Baseline questionnaire and clinical examinations focusing on function and dysfunction of the masticatory system were performed in a sample of 402 subjects 7, 11, and 15 years old. After 20 years, 320 subjects (80% of the original sample) completed a similar questionnaire as at baseline. From the oldest age group, now aged 35 years, 100 subjects (74% of the original sample) also attended a clinical examination. Three variables from the 20-year follow-up were chosen as dependent variables in logistic regression analyses, with independent variables selected from the baseline examinations. Three variables at baseline were significant predictors for reported TMJ clicking at the 20-year follow-up, tooth wear index being the strongest (odds ratio = 4.3). Reported TMJ clicking at the start was the only significant predictor for TMD symptoms without clicking 20 years later (odds ratio = 2.3). The third logistic regression model, using the Helkimo Clinical Dysfunction Score as dependent variable, resulted in four significant predictors from the baseline examinations (bruxism, oral parafunctions, TMJ clicking, and deep bite). The results indicated that some signs and symptoms might predict TMD signs and symptoms in a long-term perspective. However, it cannot be concluded from this study whether these symptoms recorded in childhood--oral parafunction, tooth wear, TMJ clicking, and deep bite--can be used for predicting manifest TMD in adult age.     

Predictors of signs and symptoms of temporomandibular disorders: a 20-year follow-up study from childhood to adulthood

The aim of this study was to find possible predictors of signs and symptoms of temporomandibular disorders (TMD) in a long-term perspective. Baseline questionnaire and clinical examinations focusing on function and dysfunction of the masticatory system were performed in a sample of 402 subjects 7, 11, and 15 years old. After 20 years, 320 subjects (80% of the original sample) completed a similar questionnaire as at baseline. From the oldest age group, now aged 35 years, 100 subjects (74% of the original sample) also attended a clinical examination. Three variables from the 20-year follow-up were chosen as dependent variables in logistic regression analyses, with independent variables selected from the baseline examinations. Three variables at baseline were significant predictors for reported TMJ clicking at the 20-year follow-up, tooth wear index being the strongest (odds ratio = 4.3). Reported TMJ clicking at the start was the only significant predictor for TMD symptoms without clicking 20 years later (odds ratio = 2.3). The third logistic regression model, using the Helkimo Clinical Dysfunction Score as dependent variable, resulted in four significant predictors from the baseline examinations (bruxism, oral parafunctions, TMJ clicking, and deep bite). The results indicated that some signs and symptoms might predict TMD signs and symptoms in a long-term perspective. However, it cannot be concluded from this study whether these symptoms recorded in childhood - oral parafunction, tooth wear, TMJ clicking, and deep bite - can be used for predicting manifest TMD in adult age.     

A comparison of clinical examination, history, and magnetic resonance imaging for identifying orthodontic patients with temporomandibular joint disorders.

The temporomandibular joint (TMJ) status of 51 juvenile orthodontic patients was assessed with magnetic resonance imaging (MRI), clinical examination, and questionnaire data. The results of this study demonstrated that the prevalence of anterior displacement of the meniscus was 11.8% (6 of 51) as assessed by MRI. Clicking or pain in the TMJ area was found in 9.8% (5 of 51) of the subjects by clinical exam, and 19.8% (10 of 51) of the subjects had a history of pain or clicking of the TMJ. Three subjects had a positive MRI and a negative history and clinical examination. However, all subjects with positive MRI findings had a history of other risk factors known to be associated with TMJ internal derangement (TMJ-ID). Therefore practitioners should use a history form and a clinical examination technique that includes a broad range of signs and symptoms of temporomandibular disorders (TMD) to identify patients who may have abnormal condyle disk relationships and be at risk for TMD. Clicking and pain in the TMJ helped identify only one half of the patients with abnormal condyle-disk relationships in this study population. Future cephalometric studies will monitor the effects of abnormal condyle disk relationships on facial growth during orthodontic treatment.     

Mouse genetic models for temporomandibular joint development and disorders

The temporomandibular joint (TMJ) is a synovial joint essential for hinge and sliding movements of the mammalian jaw. Temporomandibular joint disorders (TMD) are dysregulations of the muscles or the TMJ in structure, function, and physiology, and result in pain, limited mandibular mobility, and TMJ noise and clicking. Although approximately 40–70% adults in the USA have at least one sign of TMD, the etiology of TMD remains largely unknown. Here, we highlight recent advances in our understanding of TMD in mouse models.     

The treatment of temporomandibular disorders with stabilizing splints in general dental practice: one-year follow-up

BACKGROUND: The authors evaluated temporomandibular disorder (TMD) outcomes in general dental practice one year after treatment with stabilizing splints (SS) or nonoccluding control splints (CS). METHODS: Seventy-two randomly allocated subjects completed initial treatment. The outcomes measures were a pain visual analog scale (VAS), muscle tenderness, temporomandibular joint (TMJ) tenderness, interincisal opening, TMJ clicks and headaches. After initial treatment, 81 percent of the subjects were found to have been treated satisfactorily. The dentists referred the remaining subjects to a dental hospital. At one year, the authors recalled 52 of the original subjects for evaluation. RESULTS: Improvements after initial treatment were maintained at one year for all outcomes, except for TMJ clicking, which returned to pretreatment levels. Eighty-one percent of the subjects rated their treatment as either good or excellent in reducing jaw pain. The authors found that subjects were aware of more of their TMJ clicks than dentists observed at the one-year clinical examination, but most subjects thought their clicking or the associated pain had been reduced. Fifty-five percent subjects had used their splints in the previous six months, but only 31 percent of these had done so daily. There were no significant differences between splint groups. CONCLUSION: At one year, a good response to TMD treatment in general practice had been maintained, but many subjects still had clicking TMJs. CLINICAL IMPLICATIONS: Trained dentists can manage TMD satisfactorily, with only a small proportion of patients needing specialist attention.     

Comparison of subjective symptoms among three diagnostic subgroups of adolescents with temporomandibular disorders

International Journal of Paediatric Dentistry 2010; 20: 458–465 Aim. To compare subjective symptoms among three diagnostic subgroups of young patients with temporomandibular disorders (TMDs). Design. We comprehensively examined 121 patients with TMDs (age ≤20 years; 90 female patients and 31 male patients) who completed self‐reported forms for assessing subjective symptoms, which consisted of five items on pain intensity in the orofacial region and six items on the level of difficulty in activities of daily living (ADL) (rating scale, 0–10). They were divided into three diagnostic subgroups: temporomandibular joint (TMJ) problem (JT) group, masticatory muscle pain (MM) group, and the group with a combination of TMJ problems and masticatory muscle pain (JM group). Their symptoms were compared using the Kruskal–Wallis and Mann–Whitney U‐tests. Results. The intensity of jaw or face tightness and difficulty in talking and yawning were not significantly different among the groups. However, the MM and JM groups had a significantly higher rating for jaw or face pain, headache, neck pain, tooth pain, and difficulty in eating soft foods (P < 0.01). Conclusions. Young patients with MM or JM report more intense pain in the orofacial region and have more difficulties in ADL than those with JT problems alone.     

Maxillomandibular relationship in TMD patients before and after short-term flat plane bite plate therapy

This study assessed the maxillomandibular relationship in temporomandibular disorders (TMD) patients, before and after short-term, flat plane bite plate therapy. It was of interest to determine the incidence and degree of mandibular deviation in a group of TMD patients and whether the mandible would shift to the midline and consequently affect reported symptoms. Seventeen female and three male subjects (age range 19-60) were included in the study. Thirteen subjects were diagnosed with myofascial pain while seven were diagnosed as exhibiting disk displacement with reduction (Research Diagnostic Criteria). After taking impressions for these subjects, casts were fabricated and mounted. Maxillomandibular relationship was evaluated by the Denar Centric Check system (Anaheim, CA). The maxillary and mandibular labial frena were used as a reference to evaluate mandibular shift. Symptom questionnaires were used to assess temporomandibular joint pain and clicking. All subjects exhibited deviation (12 subjects to the right and 8 subjects to the left) prior to bite plate therapy. After flat plane bite plate therapy, the mandibular position of all subjects shifted toward the labial frenum midline position. Based on the Binomial test, the shift was significant (p < 0.001). Measurements on the Centric Check system showed a significant movement of both condyles in the anterio-posterior plane as well as the vertical plane. There was also significant reduction in TMJ pain and clicking (p < 0.01). The results support the hypothesis that the balanced position of the mandible is with frena aligned. When occlusal obstructions are eliminated, the mandible will drift to this position.     

Dental malocclusion is not related to temporomandibular joint clicking: a logistic regression analysis in a patient population

Objectives:To assess the association of several dental malocclusion features with temporomandibular joint (TMJ) click sounds in a population of temporomandibular disorder (TMD) patients.Materials and Methods:Four hundred forty-two TMD patients (72% female; 32.2 ± 5.7 years, range 25–44 years) were divided into a TMJ clicking and a no-TMJ clicking group, based on the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) assessment. Seven occlusal features were recorded for each patient: (1) posterior crossbite, (2) overbite, (3) open bite, (4) overjet, (5) mediotrusive and (6) laterotrusive interferences and (7) retruded contact position to maximum intercuspation (RCP-MI) slide length. A logistic regression model was created to estimate the association of occlusal features with TMJ clicking.Results:The difference between the groups as for the prevalence of the various occlusal features was generally not statistically significant, with minor exceptions. Mediotrusive interferences (P  =  .015) and RCP-MI slide ≥2 mm (P  =  .001) were the two occlusal features that were associated with the probability of having TMJ clicking, even if the adjusted odds ratios for TMJ clicking were low for both variables (1.63 and 1.89, respectively). Moreover, the amount of variance in the prevalence of TMJ clicking that was predicted by the final model was as low as 4.5% (R²  =  0.045).Conclusions:Findings from the present investigation suggested that in a population of TMD patients, the contribution of dental malocclusion features to predict TMJ click sounds is minimal with no clinical relevance.     

Association of caries and treatment experiences with subjective symptoms of temporomandibular disorders in female adolescents

A 2-year cohort study of subjective symptoms of temporomandibular disorders (TMD) was performed. A total of 229 female adolescents, all 15 years of age, completed questionnaires and underwent dental examinations at baseline, 1- and 2-year follow-up surveys. The questionnaire included questions on typical TMD symptoms; i.e. temporomandibular joint (TMJ) noise, tiredness in jaws, pain on jaw movements, and difficulty in mouth opening. The relative risk was computed to determine the relationships of the baseline number of filled teeth (FT) and decayed, missing and filled teeth (DMFT) increment with the incidence of TMD. The percentage of subjects with one or more subjective symptoms at 17 years of age was 30.6%, significantly higher than the percentages at 15 (17.0%) and 16 (19.7%) years of age (P < 0.01). The symptom-emerging rate of TMJ noise during the 2-year period was 13.5%, which was the highest among the rates of possible subjective symptoms. Individuals with a 2-year increment in DMFT of > or =2 had a 2.14-times increased risk of experiencing mild symptoms, and individuals with baseline FT of > or =3 had 2.41-times increased risk of experiencing mild or severe subjective symptoms. The results of this study showed that TMD symptoms occurred in a relatively high percentage of female adolescents during the 2-year period and suggested that DMFT is one factor affecting the incidence of TMD.     

Temporomandibular disorders in 19-year-old Korean men.

PURPOSE: The purpose of this study was to determine the prevalence and the nature of the relationships between 3 temporomandibular joint disease (TMD) symptoms and symptoms of associated structures. MATERIALS AND METHODS: This study was designed to rule out the effect from the uneven composition of the samples on TMD symptoms. The samples were collected from subjects who were of the same age, gender, district, and race. Nineteen-year old men (n = 27,978) were selected and investigated by means of questionnaires and clinical examinations. The prevalence of each symptom was studied and tried to determine the effects of the TMD-associated signs on the TMD signs. The indices allocated to reflect the TMD signs and symptoms and the others were dichotomized for bivariate analysis. The predictor variables were headache, neck pain, referred pain, stress, past trauma history in the TMJ, past TMJ dislocation, bruxism, and clenching. The outcome variables were mouth opening limitation, TMJ pain on rest, and TMJ pain during function. RESULTS: The incidence of masticatory muscle stiffness was 17.8%; TMJ sounds, 14.3%; headache, 7.2%; neck pain, 13.5%; bruxism, 8.4%; and clenching, 9.9%. Stress occurred in 12.8%, past trauma history in 11%, and previous joint dislocation in 2.5%. The experience of dislocation in the TMJ was found to be the most important risk factor in terms of mouth opening limitation (odds ratio, 4.08, P <.0001), joint pain during function (odds ratio, 5.50, P <.0001), and joint pain in the rest state (odds ratio, 4.63, P <.0001). Referred pain and the experience of trauma in TMJ were the secondary risk factors in terms of joint pain and referred pain and the stress in terms of mouth opening limitation. Considering referred pain can be induced by TMD, stress may be more related to mouth opening limitation (odds ratio, 2.18, P <.0001), and the experience of trauma in TMJ may be more related to pain in the rest state (odds ratio, 2.56, P <.0001) and during function (odds ratio, 2.47, P <.0001). CONCLUSIONS: The prevalence of TMD signs and symptoms as determined by this examination was in accord with the findings in women or mixed samples of other workers. Prior experience of a dislocated disc was found to be the most risky factor in TMD. Stress was related to limitations of mouth opening, and the experience of trauma in the TMJ was found to be related to pain in the joint region. Bruxism may not be a direct risk factor in TMD, and the clenching habit found to be more harmful than bruxism.     

Incidence of temporomandibular joint symptoms following whiplash injury.

Recently there has been considerable litigation involving the development of temporomandibular joint (TMJ) pain and dysfunction following cervical musculoskeletal injury (whiplash). The purpose of this investigation was to interview, examine, and follow up patients with a diagnosis of whiplash injury to determine the incidence of associated temporomandibular disorders. Patients were divided into two categories: those with and those without radiologic evidence of cervical skeletal injury. In the 63 patients with radiographic evidence of cervical skeletal injury (group 1), none had clicking at the time of initial examination. In the 92 patients without positive radiographs (group 2), only one had clicking. At 1 month follow-up by telephone, 2 of 51 available patients in group 1 had developed clicking, but no new TMJ symptoms were reported by the 78 patients in group 2 contacted by phone. Seventy percent of the initial follow-up group (44 patients) with radiographic evidence of injury were contacted by telephone at 1 year and none reported new symptoms of TMJ pain or clicking. Sixty-five percent of the initial follow-up group without radiographic evidence of injury (60 patients) were interviewed and also reported no new TMJ symptoms. These data indicate that the incidence of TMJ pain and clicking following whiplash injury is extremely low, and that patients who do not have clicking on resolution of their initial pain/dysfunction subsequently do not develop this problem.