Materials and manufacturing techniques for occlusal splints: A literature review.

OBJECTIVE: To review the materials and fabrications methods of occlusal splints with their advantages and shortcomings and to clarify the indications for each. BACKGROUND: Temporomandibular joint disorders (TMDs) encompass a range of conditions affecting the masticatory system. Occlusal splints are currently recognised as a viable option for the management of TMDs when they are adopted in conjunction with additional approaches varying from conservative procedures (counselling, biofeedback, physical therapy, pharmacotherapy) to irreversible and less conservative ones (occlusal adjustments, orthodontics, arthroscopy and surgery). These splints can vary in design, function and material. The components used to fabricate the splints must withstand occlusal forces, be aesthetically pleasing, comfortable and minimally interfering with function and phonetics. Traditional methods for fabricating splints include sprinkle-on, thermoforming and lost wax techniques. However, with the advancement of CAD/CAM technology, additive (3D printing) and subtractive (milling) manufacturing methods expand the range of possibilities by introducing novel solutions for elaborating splints. METHODS: An electronic search was conducted on PubMed using the following keywords: "occlusal splint", "guard and "materials", and "manufacturing." Thirteen in vitro publications were screened and they consisted of four clinical studies, nine reviews (three of them were systematic reviews), and five case reports. CONCLUSION: The choice of material is crucial for the success of splint therapy. Factors such as biocompatibility, ease of fabrication, adjustability, cost and patient preference should be considered. Newer materials and techniques are emerging because of advancements in material science and manufacturing techniques. However, it should be noted that most of the evidence is based on in vitro studies with different methodologies, limiting their validity in daily practice.

Platelet-rich plasma injections for the treatment of temporomandibular joint disorders: A systematic review.

OBJECTIVE: This systematic review aimed to investigate and examine whether intra-articular injections of platelet-rich plasma (PRP) after arthrocentesis are beneficial for the treatment of temporomandibular disorders, when compared to other treatments, such as injections of hyaluronic acid (HA) or saline after arthrocentesis. METHODS: An electronic search on PubMed was performed using combinations of the terms 'temporomandibular' and 'platelet rich plasma', to identify studies reported in English and published up until 2017. The initial screening identified 222 records, of which only seven fulfilled the inclusion criteria and were included in this review. Of these studies, three compared injection of PRP after arthrocentesis with the injection of HA after arthrocentesis, while two compared injection of PRP after arthrocentesis with Ringer's lactate after arthrocentesis and one compared injection of PRP after arthrocentesis to sodium chloride. RESULTS: Five of the studies found that PRP injections have led to significant improvements in mandibular range of motion and pain intensity up to 12 months after treatment, while the remaining two studies found similar results for the different treatments. CONCLUSION: However, a standardized protocol for PRP preparation and application needs to be established.

The Prevalence and Predicting Factors of Temporomandibular Disorders in COVID-19 Infection: A Cross-Sectional Study.

Introduction During the pandemic of coronavirus disease 2019 (COVID-19), an increase in temporomandibular disorders (TMDs) was noticed in infected patients. In the present study, we aimed to assess the prevalence of TMDs during COVID-19 infection and to evaluate associated factors. Methods An observational cross-sectional online survey was conducted in April and May 2021 in order to estimate the prevalence of TMDs in participants who were previously infected with COVID-19. A multivariable logistic regression model was carried out to explore predicting factors of TMDs during COVID-19 infection. Results In total, the prevalence of TMDs during the COVID-19 infection period among participants was 41.9%. High fever episodes (adjusted odds ratio {aOR}: 3.25), gastro-esophageal reflux (aOR: 2.56), and toothache (aOR: 3.83) during COVID-19 illness were found to be positive predictors of TMDs, while vitamin D deficiency was found to be a negative predictor (aOR: 0.28). Conclusion Our study has highlighted a relatively high prevalence of TMDs in COVID-19-infected patients that may conclude TMDs as a possible COVID-19 symptom. Further studies are warranted to confirm the association between TMDs and COVID-19 infection and thereupon include TMDs among the known symptoms of COVID-19.

Effect of Occlusal Splints on Posture Balance in Patients with Temporomandibular Joint Disorder: A Prospective Study.

AIM AND OBJECTIVE: Force platforms are widely used to evaluate the relationship between bodily posture and jaw positions. The aim and objective of this clinical prospective study was to evaluate the effect of occlusal splints on bodily posture using force platforms. MATERIALS AND METHODS: Forty-seven female patients with temporomandibular disorders (TMD) underwent a clinical and postural examination before and during an occlusal treatment with an upper splint. Six postural stabilometric examinations were performed under different visual conditions. Postural stability was assessed using a force platform (SATEL). Subjects were evaluated in static and dynamic conditions, with open and closed eyes, at baseline, at 1 week, and at 3 months. Changes in stabilometric parameters (sway area and sway length) were assessed and compared. RESULTS: In static and dynamic positions, the sway surface area decreased significantly after the occlusal guard placement with closed eyes (p-value, 0.012). Likewise, the sway surface area decreased significantly in the dynamic lateral position with closed eyes (p-value, 0.018) and in anteroposterior dynamic position with open eyes (p-value, 0.031). The mean sway length decreased significantly after the placement of the occlusal guard when participants were in the lateral position with open eyes (p-value, 0.025) and in the anteroposterior position with open eyes (p-value, 0.014). On a 3-month assessment, the mean surface and mean length decreased significantly after the placement of the occlusal guard for practically all the static and dynamic positions. CONCLUSION: The sway surface area and sway length decreased significantly with the use of occlusal splints Clinical significance: In female patients with TMD, the use of an occlusal splint is associated with a postural improvement evaluated by posturo-stabilometric tests.