Temporomandibular disorder in construction workers associated with ANKK1 and DRD2 genes

Abstract The study aimed to explore the influence of genetic polymorphisms in ANKK1 and DRD2 on the signs and symptoms of temporomandibular disorder (TMD) in construction workers. This cross-sectional study included only male subjects. All construction workers were healthy and over 18 years age. Illiterate workers and functionally illiterate workers were excluded. The diagnosis of TMD was established according to the Research Diagnostic Criteria for TMD (RDC/TMD). Genomic DNA was used to evaluate the genetic polymorphisms ANKK1 (rs1800497) and DRD2 (rs6275; rs6276) using Real-Time PCR. Chi-square or Fisher exact tests were used to evaluate genotypes and allele distribution among the studied phenotypes. The established alpha of this study was 5%. The sample included a total of 115 patients. The age of the patients ranged from 19 to 70 years (mean age 38.2; standard deviation 11.7). Chronic pain (87.7%), disc displacement (38.2%), and joint inflammation (26.9%) were the most frequently observed signs and symptoms. The genetic polymorphism rs6276 in DRD2 was associated with chronic pain (p=0.033). In conclusion, our study suggests that genetic polymorphisms in DRD2 and ANKK1 may influence TMD signs and symptoms in a group of male construction workers.

Resumo O objetivo do estudo foi explorar a influência de polimorfismos genéticos em ANKK1 e DRD2 sobre os sinais e sintomas da disfunção temporomandibular (DTM) em trabalhadores da construção civil. Este estudo transversal incluiu apenas indivíduos do sexo masculino. Todos os trabalhadores da construção civil eram saudáveis ​​e maiores de 18 anos. Foram excluídos os trabalhadores analfabetos e analfabetos funcionais. O diagnóstico de DTM foi estabelecido de acordo com o Research Diagnostic Criteria para DTM (RDC/TMD). O DNA genômico foi usado para avaliar os polimorfismos genéticos ANKK1 (rs1800497) e DRD2 (rs6275; rs6276) usando PCR em tempo real. Testes qui-quadrado ou exato de Fisher foram utilizados para avaliar genótipos e distribuição de alelos entre os fenótipos estudados. O alfa estabelecido deste estudo foi de 5%. A amostra incluiu um total de 115 pacientes. A idade dos pacientes variou de 19 a 70 anos (média de idade 38,2; desvio padrão 11,7). Dor crônica (87,7%), deslocamento de disco (38,2%) e inflamação articular (26,9%) foram os sinais e sintomas mais observados. O polimorfismo genético rs6276 em DRD2 foi associado a dor crônica (p=0,033). Em conclusão, nosso estudo sugere que polimorfismos genéticos em DRD2 e ANKK1 podem influenciar sinais e sintomas de DTM em um grupo de trabalhadores da construção civil do sexo masculino.

Reestablishing aesthetic and function of patient with severe worn dentition: a conservative approach with provisional fixed tooth/implant supported prosthesis

Introduction:Patients with severe parafunctional habits can have a reduction of their occlusal vertical dimension (OVD) and may create complex cases of oral rehabilitation, in which the patient may develop occlusal, masticatory and psychological problems. Objective: To report a clinical case of restoration of masticatory function and aesthetics from the production of tooth/implant-supported prostheses with conservative preparations, reestablishing the OVD and occlusal stability.Case report: Patient MVN, 55 years old, wheelchair user, presenting bruxism with a history of gastric reflux due to hiatal hernia, attended the clinic at the University complaining of dental sensitivity, difficulty in chewing and aesthetic smile commitment. At clinical examination it was found widespread wear of teeth. Radiographic examination showed good periodontal health and dental implants in good condition of osseointegration. The OVD was established from the VDR and confirmed by the metric method. The initial casts were positioned on the articulator for diagnostic waxing. From the waxing it was possible to make provisional fixed tooth/implant-supported prostheses. In the lower arch, the prosthesis was screwed on the implants #35, #37, #46, and #47, with the remaining teeth working as an auxiliary support, while in the upper arch two interim prosthesis were made, one for the elements #16 and #17 (tooth-supported) and one for the elements #13, #12, #11, #21, #22, #23, #24 (tooth/implant-supported). Thus, the OVD and the aesthetics lost by bruxism abrasion were restored. Conclusion:This case demonstrates the importance of the provisional prostheses for aesthetic and functional rehabilitation of patients with severe worn dentition.

Microabrasion and composite resin for re-establishing smile esthetics: a case report

Introduction:Dental hypomineralization such as dental fluorosis has increased in recent times leading to unaesthetic appearance of teeth. There are different treatment possibilities to improve the aesthetic appearance of hypomineralized enamel described in dental literature. The enamel microabrasion has been a feasible alternative, since it is a fast, safe, conservative, and easy to perform, which promotes good esthetic results. Moreover, this technique is a conservative method that improves the appearance of the teeth by restoring bright and superficial smoothness, without causing significant structural loss. The association of different techniques, such as direct composite resin, can provide good esthetic outcomes, but the etiology, intensity, and depth of stain should be considered to minimize dental structure loss. Objective: To describe an easy technique for managing dental fluorosis using enamel microabrasion in association with direct composite resin. Case report: A mixture of hydrochloric acid and silicon carbide was applied according the manufacturer's instructions. Subsequently, a direct composite resin was applied over the areas where the opacities were more evident. This conservative approach may be considered an interesting alternative treatment to remove fluorosis staining and to improve aesthetic appearance. Conclusion: enamel microabrasion combined with direct composite resin is a conservative and safe alternative method to treat enamel opacities from dental fluorosis. Therefore, this management provides satisfactory aesthetic results for the patient's smile.

An Indirect Method to Measure Abutment Screw Preload: A Pilot Study Based on Micro-CT Scanning

This study aimed to measure the preload in different implant platform geometries based on micro-CT images. External hexagon (EH) implants and Morse Tapered (MT) implants (n=5) were used for the preload measurement. The abutment screws were scanned in micro-CT to obtain their virtual models, which were used to record their initial length. The abutments were screwed on the implant with a 20 Ncm torque and the set composed by implant, abutment screw and abutment were taken to the micro-CT scanner to obtain virtual slices of the specimens. These slices allowed the measurement of screw lengths after torque application and based on the screw elongation. Preload values were calculated using the Hooke's Law. The preloads of both groups were compared by independent t-test. Removal torque of each specimen was recorded. To evaluate the accuracy of the micro-CT technique, three rods with known lengths were scanned and the length of their virtual model was measured and compared with the original length. One rod was scanned four times to evaluate the measuring method variation. There was no difference between groups for preload (EH = 461.6 N and MT = 477.4 N), but the EH group showed higher removal torque values (13.8±4.7 against 8.2±3.6 Ncm for MT group). The micro-CT technique showed a variability of 0.053% and repeatability showed an error of 0.23 to 0.28%. Within the limitations of this study, there was no difference between external hexagon and Morse taper for preload. The method using micro-CT may be considered for preload calculation.

Resumo Este estudo teve como objetivo medir a pré-carga em diferentes conexões implante/pilar baseado em imagens de micro-CT. Implantes de hexágono externo (EH) e Cone Morse (MT) (n = 5) foram utilizados para a medição de pré-carga. Os parafusos de pilares foram digitalizados em um micro-CT de alta resolução para obter seus modelos virtuais, que foram utilizados para registrar o comprimento inicial. Os pilares foram parafusados sobre o implante com um torque de 20 Ncm e, o conjunto composto por implante, parafuso do pilar e pilar foi levado para o micro-CT para obter cortes virtuais dos espécimes. Esses cortes permitiram a medida do comprimento dos parafusos após a aplicação do torque. Assim, com base no alongamento dos parafusos, os valores de pré-carga foram calculados usando a Lei de Hooke. A pré-carga de ambos os grupos foram comparados pelo Test-t independente. O torque de remoção de cada espécime foi registrado. Para avaliar a precisão da técnica de micro-CT, três bastões foram escaneados em micro-CT e o comprimento do seu modelo virtual foi comparado com o comprimento original dos bastões. Um bastão foi digitalizado e mensurado quatro vezes para avaliar a variação do método de medição e a sua repetitividade. Não houve diferença entre os grupos para a pré-carga (EH = 461,6 N e MT = 477,4 N), no entanto o grupo EH apresentou maiores valores de torque de afrouxamento do parafuso (13,8 ± 4,7 contra 8,2 ± 3,6 Ncm para o grupo MT). A técnica de micro-CT mostrou uma variabilidade de 0,053% e a repetitividade apresentou um erro de 0,23 a 0,28%. Dentro das limitações deste estudo, não houve diferença entre Hexágono Externo e Cone Morse para pré-carga. O método baseado em imagens de micro-CT pode ser considerado para mensuração da pré-carga.