Real‐time three‐dimensional jaw tracking in temporomandibular disorders

When a dysfunction occurs in any component of the stomatognathic system, temporomandibular disorders (TMD) may originate. The aim of this study was to compare the deviations, displacement and the execution speed of mandibular movements among asymptomatic participants and those with TMD. Convenience sampling was used; forty participants diagnosed by clinical evaluation following the Research Diagnostic Criteria for Temporomandibular Disorders were divided into three groups: arthropathy (GART, 10 participants, 40% men), myopathy (GMYO, 10 participants, 30% men), and the control group (CG, 20 asymptomatic participants, 25% men). Participants were asked to perform the movements of free maximal mouth opening and closing, right and left lateral excursions, and protrusion with sliding teeth contacts. The mandibular trajectory was recorded using opto‐electronic devices tracking reflective markers placed in front of the ‘soft tissue pogonion point’. The movements were analysed on the following axis: x – medial‐lateral, y – vertical, z – antero‐posterior. Significative differences were found in CGxGART – unassisted maximal mouth opening and closing projection on y‐axis (OCY), CGxGMYO – unassisted maximal mouth opening and closing projection on x‐axis (OCX), and in the measures Opening lateral deviation on x‐axis (OLDX), closing lateral deviation on x‐axis (CLDX) and in the measures of speed for both. In regard to GARTxGMYO, a significative difference was found in Protrusion lateral deviation on x‐axis (PLDX) ‘Conover‐Iman Test of Multiple Comparisons Using Rank Sums’ using Bonferroni correction (P < 0·05). In conclusion, the total opening movements in individuals with TMD tended to have higher deviation than in those asymptomatic individuals and a reduction in the speed of movements.     

The action of anti-inflammatory agents in healthy temporomandibular joint synovial tissues is sex-dependent

This study evaluated the effects of dexamethasone, parecoxib, and glucosamine on cartilage thickness and cytokine levels in the temporomandibular joint (TMJ). Forty-eight rats (24 female, 24 male) were assigned to four treatments administered once daily for 7 days: control (saline intramuscularly), parecoxib (0.3 mg/kg intramuscularly), dexamethasone (0.1 mg/kg intramuscularly), and glucosamine (80 mg/kg orally). The thickness of TMJ cartilage and levels of four cytokines were measured. Median cartilage thickness was higher in males than in females in the control (253.2 vs. 240.4 μm, P = 0.0036), parecoxib (227.3 vs. 192.1 μm, P < 0.0001), and dexamethasone (227.1 vs. 170.5 μm, P = 0.017) groups, but was lower in males in the glucosamine group (214.5 vs. 239.6 μm, P = 0.0001). IL-1β was not detected. Median IL-1α levels differed between males and females in the parecoxib group (0.08 vs. 0.04 ng/ml, P = 0.0055), but not in the control (0.07 vs. 0.06 ng/ml), dexamethasone (0.06 vs. 0.04 ng/ml), or glucosamine (0.08 ng/ml vs. 0.06 ng/ml) groups (all P > 0.05). Only dexamethasone induced lower IL-6 levels in males than in females (median 4.6 vs. 2.1 ng/ml, P = 0.0044). Median TNF-α levels did not differ between males and females in the control (0.07 vs. 0.05 ng/ml) or parecoxib (0.07 vs. 0.05 ng/ml) groups (both P > 0.05), but dexamethasone (0.09 vs. 0.05 ng/ml, P = 0.0002) and glucosamine (0.09 vs. 0.07 ng/ml, P = 0.0259) induced higher TNF-α levels in females. Thus, the effects of the three treatments on the levels of cytokines and thickness of condylar cartilage were sex-dependent.     

Tissue engineering osteochondral implants for temporomandibular joint repair

Tissue engineering has provided an alternative to traditional strategies to repair and regenerate temporomandibular joints (TMJ). A successful strategy to engineer osteochondral tissue, such as that found in the TMJ, will produce tissue that is both biologically and mechanically functional. Image-based design (IBD) and solid free-form (SFF) fabrication can be used to generate scaffolds that are load bearing and match patient and defect site geometry. The objective of this study was to demonstrate how scaffold design, materials, and biological factors can be used in an integrated approach to regenerate a multi-tissue interface. IBD and SFF were first used to create biomimetic scaffolds with appropriate bulk geometry and microarchitecture. Biphasic composite scaffolds were then manufactured with the same techniques and used to simultaneously generate bone and cartilage in discrete regions and provide for the development of a stable interface between cartilage and subchondral bone. Poly-l-lactic acid/hydroxyapatite composite scaffolds were differentially seeded with fibroblasts transduced with an adenovirus expressing bone morphogenetic protein-7 in the ceramic phase and fully differentiated chondrocytes in the polymeric phase, and were subcutaneously implanted into mice. Following implantation in the ectopic site, the biphasic scaffolds promoted the simultaneous growth of bone, cartilage, and a mineralized interface tissue. Within the ceramic phase, the pockets of tissue generated included blood vessels, marrow stroma, and adipose tissue. This combination of IBD and SFF-fabricated biphasic scaffolds with gene and cell therapy is a promising approach to regenerate osteochondral defects and, ultimately, the TMJ.     

Clinical findings in temporomandibular joint osteoarthrosis

abstract – The clinical findings in 20 patients with TMJ-crepitation (E₁-group) and 19 patients with TMJ palpatory tenderness (E₂-group) have been compared with the findings in 29 other patients with mandibular dysfunction (R-group). The patients underwent a clinical examination of the masticator system and of the second distal interphalangeal joints (DIP II joints). No statistically significant differences could be found between groups with respect to clinical signs, occlusal interferences, or dental attrition. Loss of molar support was found to be significantly more frequent in the E₁-group than in the R-group. The frequency of tenderness to palpation or pain on movement of DIP II joints was significantly higher in the E₂-group than in the R-group. Periarticular bony swelling of DIP II joints was significantly correlated with TMJ-crepitation. The patients with TMJ-crepitation were considered to have TMJ-osteoarthrosis. The results of the present study indicate that patients with TMJ-OA have a similar clinical picture to other patients with mandibular dysfunction and that molar loss plays a role in the etiology of TMJ-OA.     

Synovial entrapment in alloplastic temporomandibular joint replacement

Complications of alloplastic temporomandibular joint (TMJ) prostheses can lead to stress and anxiety for the patient and the surgical team, and prosthesis substitution is sometimes required. The aim of this case report is to describe the surgical finding of synovial entrapment with interposed fibrosis in a postoperative alloplastic TMJ revision, managed effectively with adequate surgical debridement. The authors believe that synovial entrapment needs to be considered as a possible postoperative complication of total joint replacement when no clear symptoms of infection, metal hypersensitivity, osteolysis, or heterotopic bone formation are present. The implications of synovial entrapment in TMJ alloplastic replacement remains relatively unpredictable and poorly understood.     

Hyaluronan metabolism in overloaded temporomandibular joint

This study aimed to examine hyaluronan (HA) metabolism in relation to the onset and progression of temporomandibular joint osteoarthritis (TMJ‐OA) induced by mechanical overloading. Two‐month‐old and 6‐month‐old C57BL/6N mice were divided into experimental and untreated control groups (n = 5/group). A sliding plate was attached to the maxillary incisors of the experimental mice for 10 days to overload the condylar cartilage in TMJ. In experimental group, profound cartilage degradation was detected in haematoxylin–eosin, Safranin‐O‐Fast Green‐stained sections. It was also shown that the cartilage degradation was greater in older mice in both the control and the experimental groups. The number of HABP‐positive cells was decreased by mechanical overloading and with age. The reduction of HA expression was correlated with the progression of cartilage degradation induced by mechanical overloading. The absolute quantification of the mRNA expression related to HA synthesis and HA degradation was also performed in each group. The mRNA expression levels of HA synthase (HAS) 2 and 3 were lower in the experimental group compared with the control group in the younger mice. In contrast, the mRNA expression levels of the HA degradation gene, HYAL2 and KIAA1199, were higher in the experimental group compared with the control group in the older mice. Thus, mechanical overload differently affected the balance of HA degradation and HA synthesis in the older and younger mice, respectively. In conclusion, mechanical overloading affects HA metabolism and it might initiate or amplify the condylar cartilage degradation.     

Complications and post-operative sequelae of temporomandibular joint arthrocentesis

Objective: To evaluate intraoperative complications and postsurgical sequelae associated with arthrocentesis of the TMJ, including injection of Sodium Hyaluronate.

Methods: This retrospective study evaluated 433 arthrocentesis procedures performed in 315 patients between January 2009 and August 2016. The authors reviewed the complications identified during the procedure and the follow-up period.

Results: Temporary swelling of the periarticular tissues (95.1%) or the external auditory canal (23.5%), ipsilateral temporary open bite (68.8%), frontalis and orbicularis oculis paresis (65.1%), preauricular hematoma (0.4%), and a case of vertigo (0.2%) were the complications detected.

Conclusions: TMJ arthrocentesis remains a procedure with a minimum number of important complications. If present, complications are generally temporary, caused by the anesthetic effect or by the soft tissue edema created by the fluid extravasation created by the irrigation procedure, and can be managed on an outpatient basis.     

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颞下颌关节强直是口腔颌面部一类严重的疾病,造成患者张口受限,语言、咀嚼功能障碍,口腔卫生状况下降,面部不对称以及小颌畸形等。本文简要介绍了颞下颌关节强直的病因、病理以及临床治疗的基础与临床研究。     

Non-compliance in patients with temporomandibular joint dysfunction

In a series of 367 patients complaining of temporomandibular joint dysfunction (TMJD) 78 individuals did not attend after their first or third visits. These non-complaint patients (subjects) were compared with patients completing treatment (controls) by means of a questionnaire. The results suggest that the reasons for non-compliance were a reluctance to wear an appliance particularly at night. The effect of excluding such patients from the analysis of clinical data is noted.     

Nomenclature and classification of temporomandibular joint disorders

Currently, there are basically two approaches to classification, one based on structural and one on positional changes occurring within the joint. Despite the increase in knowledge of pathologic changes occurring within the temporomandibular joint (TMJ), the disc still seems to be a central issue in nomenclature and classifications of TMJ disorders. Basic pathologies of the TMJ involve inflammation and degeneration in arthritic disorders (irrespective of the presence or position of the disc) and structural aberrations in growth disorders. Some internal derangements may occur independent of underlying pathology, e.g. because of a traumatic event. In this position paper, a classification of TMJ disorders is proposed based on basic structural changes occurring in the joint.     

Activator矫治对颞下颌关节的影响及其与颞下颌关节紊乱病的关系

Activator矫治器是较早用于临床的功能矫治器,由Andresen于1908年设计,对安氏Ⅱ类1分类错(牙合)畸形患者有良好的治疗效果,通过前移下颌刺激下颌骨的生长且抑制上颌矢状向生长,从而调节上下颌骨矢状向的关系.目前,关于Activator矫治器的矫治原理还存在较多的分歧,其中之一就有Activator是否能刺...     

The effect of omega-3 in temporomandibular joint synovial tissues of rats with induced arthritis: pilot study

This study evaluated the effect of systemic administration of omega-3 on the expression of interleukins IL-1β and IL-10 and tumour necrosis factor alpha (TNF-α) and on the thickness of cartilage in the temporomandibular joint (TMJ) inflammatory model induced by complete Freund’s adjuvant (CFA). Thirty-two adult rats were divided equally into four groups: control, CFA (induced arthritis), and induced arthritis animals treated with dexamethasone or omega-3. The TMJs were then removed and assigned to histomorphometric analysis or immunoassay. The Kruskal–Wallis test with Dunn post hoc test was applied to the data; the significance level was set at 5%. IL-1β levels (median; interquartile range) were higher (P < 0.0001) in the CFA group (46.4 ng/ml; 39.4–53.3) than in the control group (1.81 ng/ml; 1.5–5.4), but there were no differences between the control, omega-3, and dexamethasone groups. TNF-α levels were also higher (P < 0.0001) in the CFA group (122.7 ng/ml; 92.9–284.7) than in the control group (29.1 ng/ml; 23.7–31.3). IL-10 levels were lowest (P < 0.0001) in the CFA group (73.5 ng/ml; 52.8–90.5), and no differences were found amongst the other groups. In conclusion, omega-3 successfully reduced the damage in the TMJ of induced arthritis rats. Further investigations are warranted to confirm whether the administration of omega-3 has a comparable effect to glucocorticoids in rheumatoid arthritis patients.     

杠杆原理在颞下颌关节脱位复位中的应用

目的:探讨杠杆原理在颞下颌关节脱位复位中的应用.方法:本组85例,急性脱位28例, 复发性脱位52例,陈旧性脱位5例.通过杠杆原理对急性前脱位和复发性脱位进行复位;对陈旧性脱位给予持续三类牵引及垂直牵引力复位.结果:急性前脱位和复发性脱位均成功复位;陈旧性脱位4例成功复位.结论:利用杠杆原理对急性前脱位及复发性脱位复位速度快,力量小,可以避免咬伤术者手指;对陈旧性脱位有较好效果,可作为首选复位方法.     

Reconstruction of the temporomandibular joint: a comparison between prefabricated and customized alloplastic prosthetic total joint systems

The implantation of an alloplastic total temporomandibular joint (TMJ) prosthesis is an innovative approach for the treatment of end-stage TMJ disorders. Two types of system exist: prefabricated (stock) and customized computer-aided design/computer-aided manufacturing (CAD/CAM) devices. A clinical study was performed to evaluate the effectiveness of these two designs. Twenty-eight patients treated between 2015 and 2017 were included and assigned to two groups: stock prostheses (group 1) and customized CAD/CAM prostheses (group 2). Clinical evaluations were performed at five time-points up to 6 months postoperative. Parameters included maximum interincisal opening, pain, diet, complications, and subjective well-being at the end of follow-up. Differences between pre-surgery and 6-month post-surgery values were highly significant (P < 0.001). No patient required a liquid diet at the end of treatment, and 66% of group 1 patients and 100% of group 2 patients reported improved well-being. Complications were observed in 32% of patients and included temporary paralysis of the facial nerve. In conclusion, clinical outcomes of stock and CAD/CAM prostheses suggested great improvements in mouth opening and reduction of pain as a result of the rehabilitation of TMJ function. Results showed comparable data for the two types of prosthesis design at 6 months postoperative.     

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颞下颌关节强直是口腔颌面部一类严重的疾病,其临床分型主要依据颞下颌关节骨性融合情况及其周围附属结构受累情况而定。临床针对颞下颌关节强直的治疗主要以手术为主,术后加以功能训练。外科手术治疗颞下颌关节强直的主要途径可以概括为以下三方面：解除关节强直的解剖因素;恢复或重建关节基本结构;对继发畸形的治疗。目前针对以上三方面的多种治疗手段各有利弊,本文将对近年来常用的手术治疗方法予以分类介绍。     

超声在颞下颌关节功能评价中的应用

颞下颌关节的功能状态关系到口腔颌面外科、正畸科和修复科等的治疗成败,超声作为颞下颌关节功能评价的一种新兴手段,以其无损伤性、经济、有效等特点得到了越来越广泛的应用。下面就超声在颞下颌关节盘位置检查、髁突运动轨迹和颞下颌关节音检测等方面的作用作一综述。     

76例颞下颌关节紊乱病患者许氏位片中髁突位置的分析

目的通过颞下颌关节紊乱病(TMD)患者的许氏位片来分析患者的髁突位置变化。方法选取76例TMD患者为研究对象,男性30例,女性46例,年龄为17～53岁。采用Cohlmia法对76例患者的双侧颞下颌关节(TMJ)的牙尖交错位标准许氏位片进行测量分析。结果76例TMD患者左侧颞下颌关节的PO1(反映髁突矢状向位置)平均值为1.220±0.422,PO2(反映髁突垂直向位置)平均值为0.386±0.085,右侧颞下颌关节的PO1平均值为1.119±0.386,PO2平均值为0.397±0.098,左、右侧髁突位置及关节窝形态的差异均无统计学意义(P>0.05)。结论在颞下颌关节紊乱病患者的许氏位片中,髁突位置变化不明显,诊断意义不大。