Modifications in Class I and Class II Div. 1 malocclusion during orthodontic treatment and their association with TMD problems

ABSTRACT

Objective: To observe changes in tooth movements of patients with Class I and Class II malocclusion during the first 6 months of orthodontic treatment and to investigate the relation between TMJ problems and these changes.

Methods: The sample was comprised of 63 individuals (20 control, 25 Class I malocclusion, 18 Class II Div. 1 malocclusion). Occlusion analysis was performed through T-Scan® record and chewing pattern examination before and after the 6-month period. The existence of TMD was evaluated using joint vibration analysis (JVA). Patients with malocclusion had active fixed orthodontic treatment.

Results: Disclusion time reduced in the patients group during the treatment period. No association was observed between the first 6-month period of the orthodontic treatment and TMD.

Discussion: It is suggested that occlusion analyses should be done before any orthodontic treatment, and disclusion time should be minimized as much as possible.     

垫治疗青少年颞下颌关节紊乱病的临床疗效分析

目的：考察[牙合]垫对青少年颞下颌关节紊乱病患者临床症状的改善情况。方法：采用稳定性[牙合]垫或再定位[牙合]垫治疗71例颞下颌关节紊乱患者，比较治疗前后张口度、颌面部疼痛和关节弹响的变化情况。结果：治疗组51例患者中疼痛34例，张口受限15例，疼痛伴张口受限14例，单纯性疼痛20例，治疗后疼痛及张口受限均得到缓解，缓解率为100％。治疗前疼痛指数和张口度分别为7．5±2．09和26．5±5．12mm，治疗后分别为2．4±1．58和40．1±5．03mm，差异均有显著性（P〈0．05）；关节弹响41例，治疗后18例弹响消失，16例弹响减轻。对照组中有2例弹响自行消失，3例疼痛自行缓解，其余无变化，差异有统计学意义（P〈0．05）。结论：[牙合]垫对颞下颌关节紊乱病患者的临床症状有显著缓解作用。     

The implementation of a decision-tree did not increase decision-making in patients with temporomandibular disorders in the public dental health service

Objective: Many patients with temporomandibular disorders (TMD) seem to go undetected within primary dental health care. Primarily we evaluated if the implemented intervention increased the clinical decision-making for TMD patients; secondarily we evaluated if other factors could be identified that predicted performed or recommended TMD treatment.

Material and Methods: This case–control study was carried out within the Public Dental Health service in Västerbotten County, Sweden. An intervention based on a decision-tree with three screening questions for TMD (3Q/TMD) was implemented during 2015 in four clinics and compared with the remaining county. A total of 400 individuals were selected—200 3Q-positives and 200 3Q-negatives. The 3Q/TMD consists of Q1—frequent jaw pain, Q2—frequent pain on function, and Q3—frequent catching and/or locking of jaw. The 3Q/TMD answers were analyzed in relation to TMD treatment and any TMD related decision that was collected from the digital dental records.

Results: The intervention did not increase the frequencies of traceable clinical decisions among patients with TMD.

Conclusions: Despite the implemented intervention aimed, the indicated undertreatment of patients with TMD remains. Future studies are still needed to gain a deeper understanding of the clinical decision-making process for TMD patients in general practice dentistry.     

Role of membrane environment and membrane-spanning protein regions in assembly and function of the Class II Major Histocompatibility complex

Class II Major Histocompatibility complex (MHC-II) is a polymorphic heterodimer that binds antigen-derived peptides and presents them on the surface of antigen presenting cells. This mechanism of antigen presentation leads to recognition by CD4 T-cells and T-cell activation, making it a critical element of adaptive immune response. For this reason, the structural determinants of MHC-II function have been of great interest for the past 30 years, resulting in a robust structural understanding of the extracellular regions of the complex. However, the membrane-localized regions have also been strongly implicated in protein-protein and protein-lipid interactions that facilitate Class II assembly, transport and function, and it is these regions that are the focus of this review. Here we describe studies that reveal the strong and selective interactions between the transmembrane domains of the MHC α, and invariant chains which, when altered, have broad reaching impacts on antigen presentation and Class II function. We also summarize work that clearly demonstrates the link between membrane lipid composition (particularly the presence of cholesterol) and MHC-II conformation, subsequent peptide binding, and downstream T-cell activation. We have integrated these studies into a comprehensive view of Class II transmembrane domain biology.     

颞下颌关节紊乱病关节盘前后界限改变的核磁共振定位研究

目的:通过对关节盘前后界限的测定,确定颞下颌关节紊乱病患者关节盘移位改变的情况,探讨其临床意义.材料与方法:16例经临床确诊为颞下颌关节紊乱病患者行颞下颌关节(TMJ)的核磁共振(MRI)检查与13例正常人的MRI影像进行对比分析.结果:T1图像矢状位时,在TMD组,关节盘前缘位于关节结节最低点垂直线前约0.43mm,而正常组则位于其前约0.13mm,两组间差异无统计学意义,闭口位时在TMD组关节盘后缘与双板区交界处约位于关节四中心垂直线81°处,而正常组则位于其93.31°处,两组间有统计学差异.结论:TMD组在闭口位时,关节盘均可有明显的前移,但前缘前移变化不大,这与关节盘形态改变状况一样均为颞下颌关节紊乱病的重要指征.     

The Tampa Scale for Kinesiophobia for Temporomandibular Disorders (TSK-TMD)

For musculoskeletal disorders like low back pain and fibromyalgia, evidence is growing for fear of movement to play an important role in the development of chronic pain. In temporomandibular disorder (TMD) patients, however, this construct has not received any attention yet. Therefore, in this paper, (1) a generally used instrument to measure fear of movement, the Dutch version of the Tampa Scale for Kinesiophobia (TSK), was adapted for its use in TMD patients (and translated for equivalence to English), (2) the psychometric properties of the Dutch version of the TSK-TMD were assessed, and (3) the association of various symptoms of TMD (i.e., pain, joint sounds, and limited jaw movements) with fear of movement was evaluated. In a sample of TMD patients (N = 301), confirmatory factor analysis indicated that a two-factor model based on 12 items provides the best fit of the TSK-TMD, with activity avoidance and somatic focus as its subscales. This two-factor solution of the Dutch TSK-TMD has generally good reliability and convergent validity. Multiple regression analysis showed that TMD functional problems (i.e., temporomandibular joint sounds or a stuck/locked feeling) were more strongly associated with fear of movement than with pain. This finding leads to new perspectives regarding the interplay between musculoskeletal complaints, cognition, and avoidance behavior. The results provide a basis for use of the 12-item version for routine assessment of fear of movement in TMD patients, and for future clinical studies, for example, to the role of fear of movement in TMD-treatment success.     

Relationship between horizontal condylar angle and radiographically detectable morphological changes of the condyle in asymptomatic and symptomatic patients with TMD

BackgroundThe relationship between horizontal condylar angle (HCA) measurements and radiographically detectable morphological changes of the condyle in patients with temporomandibular disorder (TMD) is an area of controversy in dentistry.AimThis study sought to determine the effect of the HCA on radiographically morphological changes in the condyles of asymptomatic and symptomatic patients with TMD.Material & methodsCone beam computed tomography (CBCT) scans were used of patients with 146 temporomandibular joints (TMJ) with and without symptoms of TMD. The reconstructed axial plane was adjusted to depict the condyle in maximum width. The HCA was established and measured as the angle formed between the condylar long axis intersecting with the coronal plane. Each condyle long axial was determined independently from the other joint by two oral and maxillofacial radiologists. The average of the readings from the two examiners was used for statistical analysis.ResultsBased on the clinical symptoms, the mean of the HCA in the symptomatic joint was 27.69°, which was slightly greater than the angle measured in asymptomatic patients of 25.6°; however, this was not a statistical difference. No significant differences existed in the mean of the HCA between the joint with and without radiographic arthritic findings in both groups. In both groups, none of the arthritic findings manifested in the affected joint that had influenced the HCA.ConclusionThe HCA was increased in the symptomatic group but had no direct influence on joint's morphological changes in the asymptomatic and symptomatic patients.     

Validation of smoke inhalation therapy to treat microbial infections

Aim of the study

In traditional healing, the burning of selected indigenous medicinal plants and the inhalation of the liberated smoke are widely accepted and a practiced route of administration. This study elucidated the rationale behind this commonly practiced treatment by examining the antimicrobial activity for five indigenous South African medicinal plants commonly administered through inhalation (Artemisia afra, Heteropyxis natalensis, Myrothamnus flabellifolius, Pellaea calomelanos and Tarchonanthus camphoratus).

Material and Methods

An apparatus was designed to simulate the burning process that occurs in a traditional setting and the smoke fraction was captured for analysis and bioassay. Methanol and acetone extracts as well as the essential oil (for the aromatic species) were prepared and assayed in parallel with the smoke fraction.

Results

Antimicrobial data revealed that in most cases, the ‘smoke-extract’ obtained after burning had lower minimum inhibitory concentration (MIC) values than the corresponding solvent extracts and essential oils. The combustion, acetone and methanol extracts produced different chromatographic profiles as demonstrated for Pellaea calomelanos where several compounds noted in the smoke fraction were not present in the other extracts.

Conclusion

These results suggest that the combustion process produces an ‘extract’ with superior antimicrobial activity and provides in vitro evidence for inhalation of medicinal smoke as an efficient mode of administration in traditional healing.