Condylar asymmetry and handedness in patients with temporomandibular disorders

summary The relationship between condylar asymmetry and handedness of dentate patients with temporomandibular disorders was investigated. A group of 28 patients (22 females and 6 males) was studied. The mean age was 28.29 years, with a range from 10 to 54 years. The association between handedness and the sign of the condylar asymmetry index was examined using Fisher's exact test. No difference was found between sign and handedness ( P >0.05). This suggests that handedness does not affect the asymmetry index in this group of patients.     

颞下颌关节紊乱综合征患者的髁突位置及对称性

目的:探讨伴有颞下颌关节紊乱综合征(temporomandibular disorders,TMD)的错(牙合)畸形患者的髁突位置及对称性.方法:在就诊的错(牙合)畸形患者中,选取有TMD症状的15例患者纳入实验组,并选取15例无症状患者作为对照组.分别对实验组和对照组行双侧颞下颌关节CT扫描,选取适当的断层并测量其关节间隙及对称性.采用SPSS17.0软件包对数据进行统计学处理.结果:实验组患者的髁突位置明显偏后位,而对照组患者的髁突位置稍前位.实验组患者患侧髁突水平倾斜角较健侧大(P＜0.05),而垂直倾斜角较健侧小(P＜0.05),两侧髁突内外径、前后径、髁突长轴、髁突中心至正中矢状面距离、两侧髁突前后距均无显著差异.结论:颞下颌关节紊乱综合征患者的髁突位置明显偏后位,且两侧髁突存在垂直向不对称.     

Condylar asymmetry measurements in patients with an Angle's Class III malocclusion

summary Condylar asymmetry/age relationships were investigated in a group of 23 dentate patients with an Angle's Class III malocclusion and no signs or symptoms of temporomandibular disorders and no prior orthodontic treatment. Condylar asymmetry was determined from panoramic radiographs. A graph of age versus asymmetry index was then plotted. There was no significant correlation between age and the asymmetry index in these patients (R²= 0.019). This is similar to results obtained for a group of patients with a Class I occlusion who were included as controls, and similar to a group of patients with an Angle's Class II division 2 malocclusion investigated previously.     

Condylar long axis and articular eminence in MRI in patients with temporomandibular disorders

ABSTRACT

Objective

To compare morphologic findings in MRI and skeletal divergence of a group of patients with temporomandibular joint disorders (TMD) subdivided into condylar symmetric and asymmetric.     

Dental asymmetry in temporomandibular disorders

In our previous study, it was reported that facial asymmetry due to mandibular lateral displacement (MLD) was significant in patients with temporomandibular disorders (TMD). In this study, dental asymmetry in TMD patients was investigated by means of PA cephalogram and study model. Lateral deviation of the midline of the mandibular occlusal table (PA-mid) and right-left difference of the molar relationship (Molar-Diff.) were examined, and their relationship with MLD was studied. PA-mid and Molar-Diff. were significantly correlated with MLD. In most cases, displaced side of the midline of the lower occlusal table was coincident with that of the mandibular skeletal midline. These results suggest that in TMD patients asymmetries in occlusal relationship of the midline of the mandibular teeth and molars were mainly due to a mandibular skeletal asymmetry and not merely due to a dental malposition on the alveolar basal bone. Many cases had a more distal occlusal relationship of the first molar on mandibular displaced side compared with that on the opposite side. A high incidence of Class II relationship was found (61.8% as a whole) and more remarkable on the mandibular displaced side. Midline discrepancy and right-left difference of the molar relationship seem to be important occlusal characteristics in patients with TMD.     

Condylar appearance in panoramic radiograms of asymptomatic subjects and patients with temporomandibular disorders

The usefulness and the limitations of panoramic radiography for the diagnosis of temporomandibular (TM) disorders were evaluated. The condylar shape appearance and the osseous changes were evaluated in asymptomatic 150 subjects (control subjects) and in 142 patients with the TM disorders who were examined by panoramic radiography. The position of the flattening and the osseous changes including osteophyte, bone erosion and osteosclerosis were objectively analyzed to determine the condylar shape. The incidence of the composite flattening type, which exhibits flattening on both the anterior and on other surfaces, was three times higher in the TM patients compared to controls. Thus, this composite type may indicate the presence of TM disorders. The incidence of osseous changes in the patients with TM disorders was significantly higher than controls and increased further in the group with the permolar and/or molar missing. This suggests that the occlusion of molar, teeth is an important factor related to the development of the TM disorders. It was concluded that panoramic radiography was useful for detecting TM disorders, at least in those with osseous changes or flattening.     

The effect of parafunction on condylar asymmetry in patients with temporomandibular disorders

This study was undertaken to examine the relationship between condylar asymmetry and parafunction in patients with temporomandibular disorders (TMD). Twenty‐eight patients with TMD and parafunction and 30 patients with TMD but no parafunction were examined. A panoramic radiograph was obtained for each patient and from this the condylar asymmetry determined. The group with parafunction showed a significantly ( P < 0·005) higher asymmetry index than did the group with no noticeable parafunction. Patients were grouped into the following age ranges: 10–19 years, 20–29 years, 30–39 years, and 40 + years. The mean asymmetry index was determined for each age range for both groups of patients. The group of patients with TMD and parafunction had a higher mean asymmetry index in all the age ranges studied. This suggests that muscle hyperactivity may be a factor in the increased asymmetry found in patients with TMD.     

Facial asymmetry in temporomandibular joint disorders

In order to investigate skeletal deviation in patients with internal derangement of the TMJ, facial asymmetry was examined by the frontal cephalogram and compared with a control group of asymptomatic subjects. It was demonstrated that mandibular lateral displacement in the patients was significantly greater than that in the controls. The degree of displacement was significantly related to the cant of the frontal occlusal plane and the frontal mandibular plane, indicating the reduced vertical dimension of the posterior occlusal level and the ramus height on the mandibular displaced side. It is concluded that facial asymmetry due to mandibular lateral displacement is a relatively common problem in patients with internal derangement of TMJ. The cant of the frontal occlusal plane seems to be an important occlusal characteristic related to temporomandibular joint dysfunction.     

Condylar bony change and self-reported parafunctional habits in prospective orthognathic surgery patients with temporomandibular disorders

OBJECTIVE: The purpose of this study was to investigate the relationship between self-reported parafunctional habits and condylar bony change and disk displacement in orthognathic surgery patients with signs and symptoms of temporomandibular joint disorders. STUDY DESIGN: This is a cross-sectional retrospective study of pretreatment helical computed tomography scans and questionnaires of 94 female orthognathic surgery patients. RESULTS: Condylar bony change, unilaterally or bilaterally, was found in 56.4% of the subjects, or 43.6% of the joints. Disk displacement, unilaterally or bilaterally, was seen in 59.6% of the subjects, or 45.7% of the joints. Bruxism and clenching was significantly associated with condylar bony change and disk displacement. Subjects with 3 or more parafunctional habits showed a significantly higher rate of bilateral condylar bony change. CONCLUSION: Our results suggest that bruxism and clenching might be related to deterioration of the temporomandibular joint and that the greater the number of parafunctional habits a subject has, the higher the risk of condylar bony change.     

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目的    探讨单侧正锁牙合患者的髁突形态特点及对称性差异,为临床诊疗提供一定的参考依据。方法    选择2007—2009年青岛大学医学院附属医院口腔正畸科收治的28例单侧正锁牙合患者为试验组,其中男13 例,女15 例,年龄14 ～39岁,平均（19.64±5.45）岁。选择同期收治的28例安氏Ⅰ类错牙合患者作为对照组,其中男10 例,女18 例,年龄14 ～38岁,平均（18.93±5.13）岁。试验组与对照组均拍摄数字全颌曲面断层片,并将其输入计算机后利用Adobe Photoshop软件测量,比较髁突形态特点。结果    （1）试验组与对照组髁突形态的不对称在性别上差异均无统计学意义（P＞0.05）。（2）试验组与对照组之间髁突上部高度（UH）的不对称指数比较差异有统计学意义（P＜0.05）,升支高度（RH）以及上部高度与升支高度之和（URH）的不对称指数比较差异无统计学意义（P＞0.05）。（3）试验组和对照组每侧髁突上部高度与升支高度的比值（U／R）及髁突高度与髁突颈部宽度的比值（H／W）差异均无统计学意义（P＞0.05）。结论    单侧正锁牙合患者髁突上部高度存在不对称,提示我们单侧正锁牙合应尽早矫治。     

颞下颌关节紊乱病患者的症状自评量表调查

目的通过对颞下颌关节紊乱病（TMD）患者的症状自评量表（SCL-90）各因子进行分析，了解其精神心理状态。方法338例就诊于北京大学口腔医学院颞下颌关节病及口颌面痛诊治中心的TMD患者填写SCL-90，采用t检验和单组设计定量资料的多元方差分析，将患者和普通人群的SCL-90各因子得分进行比较。结果①TMD患者SCL-90中的躯体化、强迫、焦虑、敌意、恐怖、精神病性因子得分高于普通人群，差异有统计学意义（P〈0．05）；②伴有精神心理障碍的TMD患者比例为23％；③对338份患者SCL-90进行可靠性分析，得出可靠系数为0．958。结论我国TMD患者的精神心理障碍问题不容忽视。SCL-90作为判断TMD患者是否伴有某些精神心理障碍的量表，在我国同样具有较好的适用性。     

Psychologic status in patients with temporomandibular disorders

PURPOSE: The aim of this study was to investigate diferrences in the prevalence of depression and somatization scores in temporomandibular disorder (TMD) patients. MATERIALS AND METHODS: One hundred fifty-four patients with single and/or multiple RDC/TMD diagnoses were classified into 7 groups based on Axis I criteria. Somatization and depression scores from the Symptom Checklist-90 were compared between groups. RESULTS: The results of this investigation indicate that patients with myofascial pain and arthralgia psychologically differed from those with disc displacement. These results were in accordance with findings that support the notion that the pain induces psychologic sequelae, at least in relation to depression and somatization. CONCLUSION: It was concluded that psychologic factors play an important role in etiopathogenesis of TMD, as demonstrated by an increase in levels of depression and somatization in TMD patients.     

Convergence defects in patients with temporomandibular disorders

The aim of this study is to show the presence of a correlation between ocular convergence defects (OCD) and temporomandibular disorders (TMD) among a group of adult subjects. The group studied was made up of 48 subjects (12 males and 36 females). The average age was 35 with a range of 19-45 years of age. The subjects presented with TMD and muscular pain and/or dysfunction. Forty-eight subjects with TMD for the case study were matched by gender and age to 48 control subjects seeking routine dental care (control group). All the subjects were examined by the same orthoptist who classified the ocular convergence degree using two tests. The first test evaluated the distances (in centimeters) of the convergence near point (3-4 cm: normal; 5-7 cm: sufficient; > 7 cm: insufficient). The second test assessed the fusional convergence using a Berens prism test (> 25 diopters: normal; between 18-25: sufficient; < 18 diopters: insufficient). In the TMD group, 36 subjects (75%) showed a compromise of convergence: 13 (36%) were classified in the 5-7 degree range and 23 (48%) in the > 7 cm degree range. The Berens test showed ten subjects (28%) in the group < 18D and 26 (72%) in the group 18-25D. The control-group presented ten (21%) subjects with compromise of convergence: three classified in the group < 18D and seven in the group 18-25D. The TMD subjects presented a higher statistical percentage (p < 0.0001) of ocular convergence defects. The TMD patients also reported a strong association referred to specific signs and symptoms, i.e., limited maximal opening or myofascial pain. There were some subjective reports also of headaches and torcicollis (neck stiffness) which appeared significantly more frequently in subjects with a compromise of convergence. The study showed a much higher prevalence of ocular convergence defects in patients with head, neck, and shoulder pain.     

Electromyographic activity in patients with temporomandibular disorders

Evaluation of masticatory muscle activity by surface electromyography (EMG) is a valuable tool for diagnosing dysfunction of the masticatory apparatus. However, controversy exists with regard to the usefulness of the EMG for patients with temporomandibular disorders (TMD). Forty patients with TMD were subjected to surface EMG of the masticatory muscles. These patients had consulted because of temporomandibular pain and clicks. In most cases (75%), the symptoms affected the patient's left side. Overall mean resting activity was 2.52 microV+/-1.25 microV (s.d.), which is slightly higher than in comparable healthy subjects (1.92+/-1.20 microV). Mean resting activity was highest in the anterior digastric muscle (3.49 microV) on the left side. Overall mean activity during clenching was 66.77+/-35.22 microV, which is about half that observed in healthy subjects (110.30+/-82.97 microV). During leftward movement of the jaw, activity was on average highest in the left digastric, while during rightward movement, activity was on average highest in the right anterior temporal (AT). Our results thus indicate that patients with temporomandibular joint (TMJ) disorder show: (1) a slight increase in basal tone; (2) a significantly reduced capacity for clenching; and (3) an apparently paradoxical inhibition of the dysfunctional-side AT during movement of the mandible towards that side.     

Tooth contact in patients with temporomandibular disorders

Both experimental and retrospective studies suggest a link between parafunctions and pain in temporomandibular disorder (TMD) patients. To investigate the role of parafunctions in TMD, experience sampling methodology was used as a prospective test of the hypothesis that patients with TMD have higher levels of tooth contact and tension than non-TMD controls. Three groups of TMD patients and a group of normal controls carried pagers for one week, were contacted approximately every two hours by an automated calling system, and completed questionnaires assessing tooth contact, tension, and pain at each contact. Results showed that tooth contact was much more frequent among normal controls than is commonly presumed. Patients with myofascial pain with/without arthralgia reported more frequent contact, higher intensity contact, and more tension than patients with disk displacement or normal controls. Increased masticatory muscle activity responsible for tooth contact and tension may be an important mechanism in the etiology and maintenance of the myofascial pain and arthralgia of TMD.     

Depression and somatization in patients with temporomandibular disorders

STATEMENT OF PROBLEM: Psychological and behavioral traits may be important for the diagnosis and management of orofacial pain. PURPOSE: This study compared the levels of depression and somatization in patients in single and multiple research diagnostic criteria for temporomandibular disorders (RDC/TMD) diagnostic groups. MATERIAL AND METHODS: The RDC/TMD was established to allow standardization and replication of research into the most common forms of muscle- and joint-related research and is divided into 2 axes: axis I, clinical TMD, and axis II, pain-related disability and psychological status. One hundred seventeen patients (28 male and 89 female; mean age, 33.3 +/- 10.3 years) with RDC/TMD-defined clinical TMD were selected. The RDC/TMD history questionnaire and examination forms were input directly into computers with the use of a software program developed at the National University of Singapore (NUS TMDv1.1 software). Axis I and II variables were generated online and automatically archived for statistical analysis. Patients were subsequently classified into 7 groups based on the presence of the various RDC/TMD axis I diagnostic groups: group A, myofascial pain only (group I); group B, disk displacement only (group II); group C, other joint conditions such as arthralgia, osteoarthritis, and osteoarthrosis only (group III); group D, myofascial pain and disk displacement (groups I and II); group E, myofascial pain and other joint conditions (groups I and III); group F, disk displacement and other joint conditions (groups II and III); and group G, myofascial pain, disk displacement, and other joint conditions (groups I, II, and III). Differences in mean Symptom Checklist-90 scores between groups were compared by analysis of variance/Scheffé tests to contrast depression and somatization levels between the various axis I diagnostic groups (alpha=.05). RESULTS: The frequencies of the different groups were as follows: group A, 26.5%; group B, 29.9%; group C, 12.8%; group D, 6.0%; group E, 13.7%; group F, 4.3%; and group G, 6.8%. Approximately 39% of patients were clinically depressed, and 55% had moderate to severe somatization. Differences in mean depression and somatization with pain item scores were significant between groups (P<.05). CONCLUSION: Within the limitations of this study, patients diagnosed with myofascial pain and other joint conditions (group E) had significantly higher levels of depression (P=.03) and somatization (P=.03) than patients diagnosed with only disk displacements (group B).     

Condylar and disk position and signs and symptoms of temporomandibular disorders in stress-free subjects

BACKGROUND: The authors conducted a study in subjects who tested free of psychological stress to determine the position of the condyle and whether that position was related to signs and symptoms of temporomandibular disorders (TMDs). METHODS: Forty subjects underwent psychological evaluation to ensure freedom from psychological stress. The authors evaluated tenderness of the masticatory muscles and temporomandibular joints (TMJs) by means of bimanual digital palpation, and they determined the positions of the condyle and disk by using magnetic resonance imaging. RESULTS: A total of 23.75 percent of the condyles were displaced away from the centric position either anteriorly (3.75 percent) or posteriorly (20.00 percent). chi(2) analysis showed a relationship between the position of the condyle and displacement of the disk, as well as a relationship between the position of the condyle and tenderness of the TMJs. CONCLUSION: Although these relationships proved significant, it cannot be assumed that displacement of the condyle away from the centric position is predictive of TMD. CLINICAL IMPLICATIONS: Only two subjects were judged to have had TMJ internal derangement. Thus, the absence of psychological stress seems to have played a role in this finding.