Skin surface temperature over the temporomandibular joint and masseter muscle in healthy children and adolescents

Skin surface temperature (SST) measurements were carried out over the temporomandibular joint (TMJ) and masseter muscle (MM) of 159 healthy children and adolescents aged 7, 11, 15 and 18 years. No current symptoms were found of impaired general health or from the masticatory system or recurrent headache. The recordings were done with a thermocouple in contact with the skin. The mean SST over the TMJ and MM increased with age, and from the youngest to the oldest group regarding the TMJ by 1.3 degrees C (right) and 1.6 degrees C (left), and for MM by 2.1 degrees C (right) and 2.5 degrees C (left). Variation in the mean difference between sides of the TMJ was 0.0-0.2 degrees C and for the MM 0.1-0.3 degrees C. The variation in SST between sides was reduced with increasing age, but was higher for MM than for TMJ in all age groups. In the 7-years group, there was a significant difference between right and left SST over TMJ and MM. It is concluded that SST increases with growth during childhood and that the SST for the TMJ is higher than MM in all age groups. The finding of a high degree of thermal symmetry between sides in all age groups may have diagnostic potential for pathological conditions involving blood flow and in evaluation of treatment of these conditions.     

Skin surface temperature over the temporomandibular joint and masseter muscle in healthy children and adolescents

Skin surface temperature (SST) measurements were carried out over the temporomandibular joint (TMJ) and masseter muscle (MM) of 159 healthy children and adolescents aged 7, 11, 15 and 18 years. No current symptoms were found of impaired general health or from the masticatory system or recurrent headache. The recordings were done with a thermocouple in contact with the skin. The mean SST over the TMJ and MM increased with age, and from the youngest to the oldest group regarding the TMJ by 1.3°C (right) and 1.6°C (left), and for MM by 2.1°C (right) and 2.5°C (left). Variation in the mean difference between sides of the TMJ was 0.0-0.2°C and for the MM 0.1-0.3°C. The variation in SST between sides was reduced with increasing age, but was higher for MM than for TMJ in all age groups. In the 7-years group, there was a significant difference between right and left SST over TMJ and MM. It is concluded that SST increases with growth during childhood and that the SST for the TMJ is higher than MM in all age groups. The finding of a high degree of thermal symmetry between sides in all age groups may have diagnostic potential for pathological conditions involving blood flow and in evaluation of treatment of these conditions.     

手术治疗颞下颌关节盘移位的近期疗效观察

目的:评价手术治疗颞下颌关节盘移位的方法和近期疗效.方法:2009年10月-2010年9月间手术治疗颞下颌关节盘移位患者9例(11侧),其中男1例、1侧,女8例、10侧,平均年龄28.4岁.术前平均开口度21.3mm.术前均行磁共振检查,明确诊断和分期,4例(5侧)行关节镜手术,5例(6侧)行关节盘锚固定术.术后进行至少3个月的临床随访和磁共振检查.结果:所有患者手术切口均一期愈合,未发生永久性面瘫等严重并发症,随访期末,平均开口度为32.8mm,磁共振复查显示关节盘髁关系保持稳定.结论:通过完善术前检查,严格掌握手术适应证,2种手术方法治疗颞下颌关节盘移位均有良好疗效.     

Normal variation in skin surface temperature over the temporomandibular joint and masseter muscle

Abstract – The range of the temperature at the skin surface overlying the temporomandibular joint (TMJ) and the origin of the superficial belly of the masseter muscle was investigated in 35 individuals with normal TM joints and 29 individuals with normal masseter muscles. The temperature was measured by a thermistor in contact with the skin. The temperature over the TMJ varied between 32.1°C and 35.5°C (average 34.3°C). The difference in temperature between right and left sides was to an average 0.3°C. The temperature over the masseter muscle ranged from 30.9°C to 35.7°C (average 33.2°C). The difference in temperature between right and left sides was an average 0.4°C. It was concluded that there is a fairly wide range of skin temperature over the normal TMJ and origin of the masseter muscle under the experimental conditions prevailing in this study but that the differences between right and left sides are fairly small. It therefore seems possible to use this thermometric method to assess inflammatory processes and/or changed metabolic activity in the TMJ and masticatory muscles.     

Lubricin in human temporomandibular joint disc: an immunohistochemical study

AimsTo evaluate, immunohistochemically, the presence and distribution of lubricin in human temporomandibular joint (TMJ) discs without any degenerative changes, obtained from autopsies, in order to elucidate the TMJ lubrication system and disc tribology.MethodsImmunohistochemistry for lubricin detection was carried out on 34 TMJ discs. Any disc had signs of degenerative or inflammatory joint disease nor disc were displaced. Sections were incubated with diluted rabbit polyclonal anti-lubricin antibody and scored according to the percentage of lubricin immunopositive cells. Three different TMJ disc tissue compartments taken from the intermediate zone were analysed, namely: the central region as well as the temporal (superior) and condylar (inferior) disc surfaces. The Friedman test, was used to compare lubricin at a protein level expression, amongst the regions of disc specimens.ResultsStaining was noted within the TMJ disc cell populations in every disc tissue sample, however, the number of disc cells immunolabelled varied according to disc tissue regions. The percentage of immunostained cells, was statistically significant lower in the central region than in each disc surface (p < 0.0001), whilst any statistically significant difference was found when comparing the two surfaces one another.ConclusionsLubricin is present in several location of TMJ disc being significantly more expressed at disc surfaces than in the central part.     

Development of temporomandibular joint ankylosis in rats: a preliminary experimental study

The objective of this study was to evaluate a model for the development of temporomandibular joint ankylosis in rats using disc removal and articular damage. In 30 adult male Wistar rats, articular damage was induced and disc removal performed in the right joint to induce ankylosis. The rats were divided into groups according to the time of killing (7, 15, 30, 60 and 90 days). Maximal mouth opening, mandibular deviation, initial and final weights, and duration of surgery were recorded and evaluated. After death, the joints were submitted to histological study in order to score the ankylosis. The mean duration of surgery was 14.23 min. Mean difference between initial and final maximal mouth opening was 3.38 mm, being greatest at the 15-day evaluation and lowest at 90 days, and was statistically significant at 15 days (p=0.043), 30 days (p=0.027) and 60 days (p=0.027). No mandibular deviation was observed at any of the evaluation times. Histological scores increased with time of evaluation from 7 to 30 days, when they started to fall. This study model permitted the development of fibrous ankylosis in the majority of the animals, and no bony bridge was observed between the mandibular condyle and the temporal bone.     

Temporalis muscle as a disc replacement in the temporomandibular joint of sheep.

Temporalis muscle flaps were evaluated in sheep. Flaps placed following discectomy were examined at 2, 4, 12, and 24 weeks. Histologic evaluation showed avascular necrosis and subsequent displacement and loss of tissue from the joint resulting in close contact between the condyle and fossa. Muscle flaps placed lateral to the joint in operative controls were examined at 4, 12, and 24 weeks. This muscle remained viable while undergoing fibrous replacement. Although the surface layers of the condyle and fossa were initially lost, the tissues were reformed with time. This experiment showed that in the sheep, temporalis muscle does not withstand functional loading within the joint. However, despite the lack of interpositional material, the condyle and fossa can remodel.     

The use of autologous auricular cartilage for temporomandibular joint disc replacement: a preliminary report

The technique of harvesting auricular cartilage and its use in 22 patients (35 joints) is described. Follow-up was from 3 to 24 months. Pain relief was achieved in 90% of the cases. Function was equal or better to the preoperative situation in all cases.     

Use of sonographic elastography of the masseter muscles for optimizing massage pressure: a preliminary study

Summary  To examine the stiffness of the masseter muscle using sonographic elastography and to investigate its relationship with the most comfortable massage pressure in the healthy volunteers. In 16 healthy volunteers (10 men and 6 women), the Masseter Stiffness Index (MSI) was measured using EUB-7000 real-time tissue elastography. They underwent massages at three kinds of pressures using the Oral Rehabilitation Robot (WAO-1). A subjective evaluation regarding the comfort of each massage was recorded on the visual analogue scale. Elastography was also performed in two patients with temporomandibular joint dysfunction with the myofascial pain. The mean MSI of the right and left muscles in the healthy volunteers were 0·85 ± 0·44 and 0·74 ± 0·35 respectively. There was no significant difference between the right and left MSI in the healthy volunteers. The MSI was related to massage pressure at which the healthy men felt most comfortable. The two temporomandibular disorder patients had a large laterality in the MSI. The MSI was related to the most comfortable massage pressure in the healthy men. The MSI can be one index for determining the massage pressure.     

Shear properties of the temporomandibular joint disc in relation to compressive and shear strain

Shear stress can result in fatigue, damage, and irreversible deformation of the temporomandibular joint disc. Insight into the dynamic shear properties of the disc may give insight into the mechanism inducing tissue failure due to shear. We tested the hypothesis that the dynamic shear properties of the disc depend on the amount of shear and compressive strain. Twenty-four porcine discs were used for dynamic shear tests. The specimens were clamped between the plates of a loading apparatus under compressive strains of 5%, 10%, and 15%. Dynamic shear was applied to the specimen by a sinusoidal strain of, respectively, 0.5%, 1.0%, and 1.5%. Both the dynamic elasticity and viscosity were proportional to compressive strain and inversely proportional to shear strain. These shear characteristics suggest a significant role of compressive and shear strain on the internal friction of the disc.     

关节盘穿孔对兔颞下颌关节影响的扫描电镜观察

目的研究兔关节盘穿孔后对颞下颌关节（TMJ）髁状突和关节盘表面超微结构的影响。方法12只3～4月龄的新西兰白兔,随机均分为实验组和对照组。以质量分数为50mg/ml的氯胺酮溶液按1ml/kg对实验动物进行肌注麻醉,对照组于无菌条件下先后暴露左右侧关节盘,实验组并以特制的穿刺针于关节盘后外侧部制作直径为2.6mm的穿孔。分别于术后12、24和36周完整取出双侧TMJ,扫描电镜观察关节盘和髁状突的变化。结果扫描电镜下可见关节盘穿孔后关节表面凝胶状物质不完整,关节盘及髁状突表面均出现明显的退行性改变：凝胶样物质掀起、剥脱,胶原纤维疏松、暴露、断裂、排列紊乱。结论关节盘穿孔可以引起TMJ表面退性行改变。     

颞下颌关节盘及其附着的组织学观察

目的 :探讨关节盘及其附着的形态特点和生理病理意义。方法 :12具尸头的 2 3侧颞下颌关节 ,每关节四等分切片 ,共 92张 ,HE染色。结果 :①颞后附着和下颌前附着较疏松 ,下颌后附着和颞前附着较致密 ,其中的纤维以前后走行为主。②关节盘中带纤维以前后走行为主 ,前、后带纤维呈多向走行。③关节盘后区有 (6/ 12例、11/ 2 3 )侧 3 3 / 92张切片显示具有第四带结构 ,其特征是盘后区由类似于关节盘内的长而致密的胶原纤维结构构成 ;3 6/ 92张 (6/ 12例 10 / 2 3侧 )张具有转纤维 ,其特点为纤维从较厚的盘后带上端突然转向后下行 ,形成明显转折角。结论 :关节盘及其附着的纤维走行特征可有不同的表现 ,可能是其功能需要的形态学反映     

Skin surface temperature over the temporomandibular joint and masseter muscle in patients with craniomandibular disorder

Skin surface temperature was measured over the temporomandibular joint (TMJ) and over the origin of the superficial portion of the masseter muscle in 59 patients with craniomandibular disorder of different character. Forty patients suffered from disorder of muscular origin, 11 from non-specific arthritis and 8 from symptomatic osteoarthrosis. The degree of mandibular dysfunction was estimated by the clinical dysfunction score and index. The temperature was measured by a thermistor applied to the skin. The clinical dysfunction score of the patients varied between 1 and 25 units. Eleven patients had a clinical dysfunction index of I, 22 had II and 26 had III. The temperature over the TMJ varied between 31.3 degrees C and 36.7 degrees C, and over the masseter muscle between 31.1 degrees C and 35.5 degrees C. The patients with unilateral tenderness to palpation of the TMJ and who were diagnosed to have TMJ arthritis had a higher skin surface temperature over the symptomatic than non-symptomatic joint. It was concluded that tenderness to palpation of the TMJ in patients with TMJ arthritis is associated with raised skin surface temperature over the joint.     

Body posture during sleep and disc displacement in the temporomandibular joint: a pilot study

Many possible factors associated with internal derangement of the temporomandibular joint (TMJ) have been discussed, but the causal factors remain unproven. The present study aimed to investigate habitual body posture during sleep (HBP) of patients with anterior disc displacement (ADD) in the TMJ. The sample comprised 87 patients (12 males, 75 females) aged 13-68 years (mean 25 years) and diagnosed by magnetic resonance imaging as having unilateral or bilateral ADD in the TMJ. The HBPs were classified into five categories: supine, prone, right lateral, left lateral, and no-dominant positions. Of the 50 patients with the unilateral ADD, 33 (66%) had the ipsilateral HBP to the affected joint while none (0%) had the contralateral HBP. This contrast showed that the HBP was a possible contributing factor to the ADD. It was suggested that HBP allows the ipsilateral condyle to displace posteriorly and this posterior position causes relative ADD.     

无症状人群颞下颌关节盘位置的核磁共振研究

目的 观察无症状志愿者颞下颌关节盘的位置,了解无症状人群中是否存在关节盘位置的异常,及其性别、左右侧分布特点.方法 无颞下颌关节病症状及病史的志愿者30名,共60例关节,其中男、女各15名,对其双侧颞下颌关节行开闭口轴位、斜矢状位和斜冠状位扫描,根据扫描结果对关节盘位置进行分类.结果 30名无症状志愿者中,正位关节盘45例,发生率为75%,其中女性20例,男性25例,右侧23例,左侧22例;前移位关节盘7例,发生率为11.67%,其中女性5例,男性2例,右侧5例,左侧2例;外侧移位关节盘6例,发生率为10%,其中女性3例,男性3例,右侧2例,左侧4例;内侧移位关节盘2例,发生率为3.33%,其中女性0例,男性2例,右侧0例,左侧2例;后移位关节盘0例,发生率为0.不同性别比较,差异无统计学意义(P>0.05),左右侧关节比较,差异无统计学意义(P>0.05).结论 无症状志愿者关节盘多为正位,但无症状人群的关节盘移位确实存在,且以前外侧旋转移位最为常见,关节盘移位类型与性别无关,左右侧分布无差异.     

Signs and symptoms of temporomandibular joint disorders in Caucasian children and adolescents

This study investigated the prevalence of the signs and symptoms of temporomandibular disorders (TMD) in a population of children and adolescents. TMD signs and symptoms were recorded in 1134 subjects (593 males and 541 females; age range 5-15 years), divided into various groups according to the: (i) Angle dental class; (ii) presence and type of crossbite; (iii) gender; and (iv) age (ages 5-11 and 12-15 years). The percentages of signs and symptoms were compared using the chi2-test to determine the differences among the groups for the rates of TMD symptoms, bruxism, joint sounds, deviation during opening, reduced opening/lateral/protrusive movements, and myofascial pain. Subjects who were 12-15 years old showed a significantly higher prevalence of myofascial pain than those who were 5-11 years old (chi2 = 4.263; p < 0.05). Females showed a significantly higher prevalence of myofascial pain than males (chi2 = 3.882; p < 0.05). Subjects with posterior, unilateral crossbite showed a significantly higher prevalence of TMD symptoms (chi2 = 33.877; p < 0.001) and reduction of functional movements (chi2 = 10.800; p < 0.05) than those with no crossbite, or with anterior or posterior bilateral crossbite. TMD's signs and symptoms seem to be associated to some definite characteristics of the patient, such as female gender, young age, and presence of posterior unilateral crossbite.     

A two-stage procedure for temporomandibular joint disc replacement using free pericranial grafts: a preliminary report

A preliminary study of the use of free pericranial grafts as an alternative to other autogenous or alloplastic materials for temporomandibular joint disc replacement is presented. Postoperative results show improved function and alleviation of other symptoms.