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.

Effect of build orientation on the trueness of occlusal splints fabricated by three-dimensional printing

PURPOSE

Scientific evidence pertaining to the evaluation of trueness of occlusal splints fabricated using different three-dimensional (3D) printers and build orientations compared to subtractive technologies is lacking.

METHODS

Overall, one hundred and ten occlusal splints were manufactured using two different 3D printers and a dental mill. Five groups of ten were fabricated using the 3D printers at different build orientations (0, 30, 45, 60, and 90 degrees). In addition, a comparison group of ten occlusal splints was subtractively manufactured using a five-axis dental mill. All occlusal splints were scanned and exported as a standard tessellation language file. Analysis was conducted with metrology software with root mean square estimate average positive deviation and average negative deviation used as the measured outcome.

RESULTS

The 0 degree printing orientation was the most accurate for printer one with the root mean square value of 0.05 ± 0.01 mm, and 60 degree printing orientation was most accurate for printer two with the RMS value of 0.11 ± 0.01 mm. Subtractively manufactured occlusal splint had significantly higher trueness with the lowest RMS value of 0.03 ± 0.05 mm.

CONCLUSION

Build orientations influence the trueness of additively manufactured occlusal splints while occlusal splints produced by subtractive manufacturing were statistically significantly more accurate.

RA.DI.CA. Splint Therapy in the Management of Temporomandibular Joint Displacement without Reduction

BACKGROUND

The purpose of this study is to report clinical and instrumental changes after RA.DI.CA splint therapy for temporomandibular joint disc displacement without reduction.

METHODS

Subjects affected by disc dislocation without reduction were recruited between July 2020 and May 2022 based on inclusion and exclusion criteria and treated with RA.DI.CA. splints over a period of 6 months. Clinical data were collected at each phase of the study (T0, T1, T2). Magnetic resonance imaging and electrognathography data were recorded at the beginning (T0) and at the end (T2) of the study. ANOVA with post-hoc contrasts was performed to assess differences in outcome measures over time. The Wilcoxon test was used to evaluate changes in disc-condyle angle between before- and after-treatment MRI. A two-tailed value of p < 0.05 was regarded as significant.

METHODS

Ten patients completed the study. There were statistically significant differences over time for arthralgia, headache, neck pain, and mouth opening. Disc recapture and an improved quality of mandibular movement were recorded in 70% of subjects. The clinical and instrumental improvements are probably due to the orthopedic action of RA.DI.CA splint treatment, which allows for a greater degree of joint mobilization.

CONCLUSIONS

The purpose of this therapy is to recover the disc position if possible and achieve an adequate joint functional adaptation that avoids the progression of the structural damage and the recurrence of symptoms.

Design and Implement Strategy of Wireless Bite Force Device

Abnormal bite force is an important risk factor for oral and maxillofacial disorders, which is a critical dilemma that dentists face every day without effective solutions. Therefore, it is of great clinical significance to develop a wireless bite force measurement device and explore quantitative measurement methods to help find effective strategies for improving occlusal diseases. This study designed the open window carrier of a bite force detection device through 3D printing technology, and then the stress sensors were integrated and embedded into a hollow structure. The sensor system mainly consisted of a pressure signal acquisition module, a main control module, and a server terminal. A machine learning algorithm will be leveraged for bite force data processing and parameter configuration in the future. This study implemented a sensor prototype system from scratch to fully evaluate each component of the intelligent device. The experimental results showed reasonable parameter metrics for the device carrier and demonstrated the feasibility of the proposed scheme for bite force measurement. An intelligent and wireless bite force device with a stress sensor system is a promising approach to occlusal disease diagnosis and treatment.

Influence of thermal cycles and disinfection on the roughness, microhardness and color of PETG/TPU and PMMA

BACKGROUND

Occlusal splints can protect teeth during bruxism, preventing tooth wear, as well as during sports activities, shielding them from impacts.

OBJECTIVES

To verify the influence of thermal cycles and disinfection on the roughness, microhardness and color of polyethylene terephthalate glycol/thermoplastic polyurethane (PETG/TPU) and poly(methyl methacrylate) (PMMA).

MATERIAL AND METHODS

Thirty-six PETG/TPU samples and 36 PMMA samples were prepared (ø10 mm × 3 mm). Six groups were created according to the material and the disinfection method used (n = 12 each): PETG/TPU (glister), PETG/TPU (hypochlorite), PETG/TPU (soap), PMMA (glister), PMMA (hypochlorite), and PMMA (soap). Roughness, Knoop microhardness and color evaluations were performed before the experiments (T1), after thermocycling (T2) and after disinfection (T3). Three-way repeated measures analysis of variance (ANOVA) and Tukey's test were used for statistical evaluations.

RESULTS

For roughness and color, ANOVA showed statistical significance based on the interaction between thermal cycling, material and disinfectant factors. In terms of Knoop microhardness, ANOVA showed statistical significance based on the interaction between thermal cycling and material factors.

CONCLUSIONS

Roughness results were clinically acceptable in all groups at all time points, except the PETG/TPU and PMMA groups disinfected with hypochlorite. Microhardness significantly increased for both materials after thermal cycling, and at all time points, the microhardness of PMMA was significantly higher than that of PETG/TPU. After thermal cycling, the color changes were clinically unacceptable in all groups.

Three-dimensional evaluation of sleep bruxism-related splint wear using a dental laboratory scanner: A preliminary clinical study

BACKGROUND

The wear depth on the occlusal splint (OS) is reportedly associated with the sleep bruxism (SB) level, as evaluated using portable polysomnography (PSG) recordings. However, the OS is deformed owing to SB forces, possibly preventing the accurate quantification of the wear facets.

OBJECTIVES

We aimed to introduce a newly developed system to quantify the wear facets on the OS using a dental laboratory scanner (D810) and investigate the association between the wear facets, as evaluated with this system, and the SB level.

METHODS

Ten healthy individuals who were diagnosed with SB based on portable PSG recordings participated in this study. They were asked to wear the OS for 2 months. The first day after a 2-week adaptation period was defined as the reference day, and sequential scanning of the OS surface was performed on days 15, 30, and 45. Changes in the OS surface from the reference day allowed dimensional evaluation of the wear facets in terms of maximum wear depth, wear area, and wear volume. Multiple regression analyses were conducted to test whether each of these variables could be predicted by any of the SB-related variables.

RESULTS

The total duration of SB episodes per hour of sleep and the maximum muscle activity were significantly associated with the wear area, as measured with our system (adjusted R-squared was .78, p < .01).

CONCLUSION

Our system allows dimensional analysis of the wear facets on the OS surface in association with the SB level.

Conservative Therapies for TMJ Closed Lock: A Randomized Controlled Trial

Background. Acute anterior disc displacement without reduction (ADDWoR) is characterized by permanent TMJ disc displacement, pain and functional limitations. Occlusal appliances (OA) are among the therapies of choice. Methods. A single-blind randomized study was carried out to compare the therapeutic success of two different types of splints in patients with ADDWoR. A total of 30 subjects were eligible for the study out of the 330 screened. Group I (n = 15) received RA.DI.CA splint therapy and Group II (n = 15) received stabilization splint therapy. Temporomandibular pain, headache, neck pain and functional excursions were evaluated at baseline (T0), after 4 weeks (T1) and after 6 months (T2). Descriptive and inferential statistics were performed. Results. There was a significant increase in maximum jaw opening and a reduction in pain in both groups (p < 0.05), except for neck pain in Group II. Significant differences in between- and within-subject factors emerged in all of the parameters evaluated, especially between T1 and T2 scores, with a greater trend of improvement in Group I than Group II. Conclusion. RA.DI.CA splints were found to be more effective for the considered sample, especially in the treatment of comorbidities and functional movements, probably due to the greater orthopedic action and joint mobilization.

Experimental Analysis of the Use of Cranial Electromyography in Athletes and Clinical Implications

Background: Cranial surface electromyography is assumed to analyze the correlation between the stomatognathic apparatus and the muscular system and its implications on the physical status of professional athletes. The purpose of this paper is to evaluate surface cranial electromyography as an aid in the diagnosis and treatment of occlusal and muscular disorders in professional athletes. Methods: A sample of 25 athletes (mean age 23 years, 20 men and 5 women) underwent electromyographic recording; among them, 13 had a sports injury condition (symptomatic athletes), while 12 were in perfect physical condition (asymptomatic athletes). At odontostomatological examination, 6 showed cranio-mandibular disorders (dysfunctional athletes), while 19 showed no disorders (functional athletes). The treatment plan to resolve the symptoms of the dysfunctional athletes was chosen based on the electromyographic data. One month after the start of therapy with an occlusal splint, a follow-up was performed, and the results were compared with the initial data. Results: Statistical analysis showed that the chosen therapy following the use of electromyography was effective in 72% of cases, while 28% of patients did not respond to therapy (p = 0.028). Conclusions: The use of cranial electromyography in competitive athletes is a valuable tool in therapeutic choice aimed at balancing occlusal loads and improving the patient’s global tonic postural attitude, resulting in positive feedback in the qualitative assessment of sports performance.

Craniovertebral and Craniomandibular Changes in Patients with Temporomandibular Joint Disorders after Physiotherapy Combined with Occlusal Splint Therapy: A Prospective Case Control Study

Background and Objectives: The aim of the study was to assess the craniovertebral and craniomandibular changes in patients diagnosed with temporomandibular joint disorders (TMD) after physiotherapy combined with occlusal splint therapy. Materials and Methods: There were forty patients (32 females, 80%), diagnosed with TMD, included into the study group. After the initial series of physiotherapy, patients received maxillary occlusal splints to be worn day and night. Participants continued physiotherapy simultaneously with occlusal splint therapy for 6 months. Lateral cephalograms taken in natural head position before and after the end of the therapy were used for measurements. The control group consisted of 15 healthy participants (12 females, 80%), who had taken lateral cephalograms twice, and did not receive any type of occlusal treatment nor physiotherapy in the meantime. Results: Occlusal splint therapy and physiotherapy combined together significantly affected: the vertical position of the mandible (significant increase, p < 0.0001), the sagittal position of mandible (significant decrease, p = 0.0065), as well as the width of the functional space between C1 and C2 (significant decrease, p = 0.0042). Moreover, the cervical lordosis was restored after the end of the treatment (p < 0.0001). Conclusions: Cooperation of physiotherapists with dental practitioners is necessary in the treatment of patients with TMD, including temporomandibular joint osteoarthritis.

Effects of stabilization splints on the signs and symptoms of temporomandibular disorders of muscular origin: A systematic review

OBJECTIVE

To assess effects of stabilization splints on signs and symptoms of temporomandibular disorders of muscular origin compared to other treatments.

METHODS

A search for articles via six electronic databases and gray literature was conducted. The risk of bias was evaluated with the Cochrane Collaboration tool. The Grading of Recommendations Assessment, Development and Evaluation approach determined the certainty of evidence.

RESULTS

Ten articles were included. Stabilization splints (n = 160 subjects) were reported to be as effective as other treatments (n = 209 patients) on analyzed outcomes (pressure pain threshold, pain during chewing, mouth opening, spontaneous pain intensity and by palpation). Five studies were judged at low and five at some concerns of risk of bias. The certainty of evidence was very low for all outcomes.

CONCLUSION

Positive effect on signs and symptoms of temporomandibular disorders of muscular origin, when managed with stabilization splint, could not be confirmed or refuted.

Case Study: A Jaw-Protruding Dental Splint Improves Running Physiology and Kinematics

Wearing an intraoral jaw-protruding splint could enhance respiratory function in clinical settings and eventually exercise performance.

PURPOSE

The authors studied the acute effect of wearing a lower-jaw-forwarding splint at different protruding percentages (30% and 50%) across a wide range of running exercise intensities.

METHODS

A case study was undertaken with a highly trained and experienced 27-year-old female triathlete. She performed the same incremental intermittent treadmill running protocol on 3 occasions wearing 3 different intraoral devices (30% and 50% maximum range and a control device) to assess running physiological and kinematic variables.

RESULTS

Both the 30% and 50% protruding splints decreased oxygen uptake and carbon dioxide production (by 4%-12% and 1%-10%, respectively) and increased ventilation and respiratory frequency (by 7%-12% and 5%-16%, respectively) along the studied running intensities. Exercise energy expenditure (approximately 1%-14%) and cost (7.8, 7.4, and 8.0 J·kg-1·m-1 for 30%, 50%, and placebo devices, respectively) were also decreased when using the jaw-protruding splints. The triathlete's lower limbs' running pattern changed by wearing the forwarding splints, decreasing the contact time and stride length by approximately 4% and increasing the stride rate by approximately 4%.

CONCLUSIONS

Wearing a jaw-protruding splint can have a positive biophysical effect on running-performance-related parameters.

Practice of Occlusal Splint Therapy for Treating Temporomandibular Disorders by General Dentists of Jabalpur - A Cross-Sectional Survey

AIM

The aim of this study was to conduct a cross-sectional questionnaire-based survey concerning the practice of occlusal splint for treating temporomandibular disorders (TMDs) by the dental practitioners of Jabalpur.

MATERIALS AND METHODS

A questionnaire containing questions on diagnosis, treatment, and management of TMD was given to a total of 157 general dental practitioners in Jabalpur. The responses were collected; data analysis was done by Chi-square test.

RESULTS

Of the General Dental Practitioner's, nearly 78% of participants did not attend any continuing dental education on TMD per year. More than 10 years of experience (82%) was associated with increase in positive response for treatment of TMD patient. Both the diagnosis and treatment of TMD patient were done using combination methods. The duration of splint use was considered patient dependent (42.27%) irrespective of the years of practice. Soft splint was most commonly employed for treatment, and fabrication of splint was done on hinge and mean value articulator.

CONCLUSION

The knowledge of occlusal splint by general practitioners was found to be insufficient for treating TMDs.

Effectiveness of remote monitoring and feedback on objective compliance with a mandibular advancement device for treatment of obstructive sleep apnea

Compliance with a mandibular advancement device is important for the optimal treatment of obstructive sleep apnea. Recent advances in information and communication technology-based monitoring and intervention for chronic diseases have enabled continuous monitoring and personalized management. Self-evaluation and self-regulation through objective monitoring and feedback may improve compliance. The aim of this study was to evaluate the effects of information and communication technology-based remote monitoring and feedback services, using a smartphone application, on the objective compliance with a mandibular advancement device in patients with obstructive sleep apnea. Forty individuals who were diagnosed with obstructive sleep apnea by polysomnography were randomly assigned to groups A and B. During an initial 6-week evaluation period, the mandibular advancement device-wearing time was monitored with the smartphone application in group B, but not in group A. The two groups then switched the monitoring procedures during the second 6-week period (the smartphone application was then used by group B, but not by group A). If no input data were indicated on the cloud server of the smartphone application during the monitored period, push notifications were provided twice daily. Objective compliance, monitored by a micro-recorder within the mandibular advancement device, was noted and compared based on whether the monitoring service was provided. The number of mandibular advancement device-wearing days was significantly higher in the monitored period than in the unmonitored period. The mandibular advancement device-wearing time did not differ significantly between the two groups. In conclusion, information and communication technology-based remote monitoring and feedback services demonstrated a potential to increase the objective measures of compliance with mandibular advancement devices.

Wear Behavior of Occlusal Splint Materials Manufactured By Various Methods: A Systematic Review

PURPOSE

To systematically review studies on various materials and methods used for wear testing of occlusal devices and their antagonists in vitro and in vivo.

METHODS

An electronic search in OVID, Web of Science, PubMed and Scopus was conducted using the following terms (MeSH words) with any synonyms and closed terms: "Splint*" OR "occlusal splint*" OR "night guard" OR "occlusal device" OR "occlusal devices" OR "deprogrammer" OR "bite splint" OR "bite plane" OR "orthotic appliance*" OR "orthotic devices" AND "wear" OR "two-body wear" OR "three-body wear" OR "tooth wear" OR "wear measurement*" OR "wear behaviour" OR "wear behavior" OR "abrasion" AND "Polymethyl Methacrylate" OR "PMMA" OR "acrylic resin*" OR "dental material*" OR "dental enamel" OR "CAD" OR "CAM" OR "PEEK" OR "material* testing". Database search was limited to English-language publications and published between 2001 and 1st of September 2021. A further hand search was done to ensure all materials were captured.

RESULTS

After the removal of duplicates, 115 studies were identified, and 11 were chosen for review. Studies showed that the lowest volumetric loss was observed in PEEK occlusal device materials, whereas heat-cure, CAD-milled, and 3D printed occlusal device materials had no significant difference in wear. Vacuum-formed materials showed the highest wear among all groups. Testing parameters were found to be inconsistent across all studies.

CONCLUSION

There is a need for standardization of in vitro and in vivo wear measurement and testing protocols as this study revealed a wide variety of testing protocols which potentially could influence the outcome. Polishing procedures are required for the material. Limited studies are available on 3D printed occlusal device materials and would therefore require further investigation, especially on printing build angles and settings. Further clinical studies would be advantageous to provide guidance on the selection of the best occlusal device material that would last the longest without remake.

Effect of contingent vibratory stimulus via an oral appliance on sleep bruxism after the splint adaptation period

BACKGROUND

Contingent vibratory feedback stimuli applied by a specially designed oral appliance (OA) have been reported to be effective in reducing sleep bruxism (SB). However, the inhibitory effects of the OA, which occur immediately after OA delivery, may have confounded this finding.

OBJECTIVE

This study sought to shed light on the effects of vibratory stimuli on SB after the OA adaptation period, when its inhibitory effects are diminished.

METHODS

Fourteen 'definite' SB patients were enrolled. A force-based bruxism detection system was utilised to trigger a vibrator attached to the OA. Masseter electromyographic activity during sleep was recorded at home using portable polysomnography. After using the OA without vibratory stimulus for 16 nights (adaptation period), intermittent vibratory stimuli were applied every other half-hour for four nights (intervention period). Electromyographic activity over 10% of the maximum voluntary contraction was regarded as a SB episode. The number and the total duration of SB episodes per hour of sleep were calculated for the sessions with and without stimuli separately and averaged for four intervention nights. The effects of stimuli on these two variables were evaluated.

RESULTS

The number and the total duration of the sessions without stimuli were 5.2 episodes/h and 35.3 s/h, respectively. These values significantly decreased to 3.9 episodes/h and 15.1 s/h (p < .05) for the sessions with vibratory stimuli.

CONCLUSION

Contingent vibratory stimulus via an OA may be effective for the management of SB even after adaptation to OA.

Influence of thermocycling and disinfection on the color stability and hardness of thermoplastic sheets used for occlusal splint fabrication

The aim of this study was to compare PETG/TPU (polyethylene terephthalate glycol/thermoplastic polyurethane) with PETG (polyethylene terephthalate glycol), based on color stability and microhardness. Sixty circular specimens (10 mm in diameter × 3 mm thick) were fabricated (30 PETG/TPU and 30 PETG). The specimens in both groups were submitted to 2000 thermal cycles in alternating baths of 60 seconds at 5°C ± 1°C and 55°C ± 1°C. The specimens were then divided into subgroups (n = 10) that were disinfected 15 minutes per day for 60 days in 1 of 3 solutions: liquid soap, 2% chlorhexidine, or Listerine. Color change (∆E*) and Knoop microhardness tests were performed at baseline (T0), after thermocycling (T1), and after disinfection (T2). Analysis of variance (ANOVA) and Tukey test were used (P < 0.05). ANOVA showed that there was no statistically significant difference in color change between the 2 materials after thermocycling (∆E*1) or after disinfection (∆E*2), regardless of the disinfectant. Intragroup comparisons (Listerine, liquid soap, and 2% chlorhexidine) of the 3 PETG/TPU groups or 3 PETG groups after disinfection revealed no statistically significant difference for microhardness. Comparison of PETG/TPU with PETG based on the overall mean microhardness showed that the PETG/TPU had a significantly greater mean surface hardness value (P < 0.05). The Tukey test revealed statistically significant increases in microhardness at T1 and T2 for PETG/TPU and PETG so that T0 < T1 < T2 (P < 0.05). Both thermoplastic materials demonstrated an increase in hardness after thermocycling and after disinfection, and both showed similar color changes regardless of the disinfection method. Based on the color evaluation, the liquid soap proved to be the best option for disinfection of PETG/TPU and PETG, because the color change (∆E* value) was clinically acceptable for both materials.

Personalized Biomechanical Analysis of the Mandible Teeth Behavior in the Treatment of Masticatory Muscles Parafunction

A 3D finite element model of the mandible dentition was developed, including 14 teeth, a periodontal ligament (PDL), and a splint made of polymethylmethacrylate (PMMA). The study considered three design options: 1—the case of splint absence; 2—the case of the splint presence installed after manufacture; and 3—the case of splint presence installed after correction (grinding) performed to ensure a uniform distribution of occlusal force between the teeth. For cases of absence and presence of splint, three measurements of the functional load were performed using the T-Scan III software and hardware complex (TekScan, Boston, MA, USA). It was found that the presence of a splint led to a decrease in the total value of the occlusive load and to a uniform distribution between all the mandible teeth. The occlusal force was considered as a static vertical force evenly distributed between the nodes belonging to the occlusive surface of the corresponding tooth for the first design option and the occlusal surface of the splint for the second and third ones, respectively. As a result of the study, it was concluded that the splint usage was effective in order to change the distribution of the functional load during the treatment of proved masticatory muscles’ parafunction; the safety of using a splint for teeth and surrounding tissues under the influence of the considered functional load was shown; the potential applicability of PMMA as a structural material of a splint that had been used for the treatment of masticatory muscles’ parafunction was established.

Medical Device Regulation: Requirements for Dental Professionals Who Prescribe and Manufacture Custom-Made Devices

A custom-made device (CMD) is a medical device intended for the sole use of a particular patient. In a dental setting, CMDs include prosthodontic devices, orthodontic appliances, bruxism splints, speech prostheses and devices for the treatment of obstructive sleep apnoea, trauma prevention and orthognathic surgery facilitation (arch bars and interocclusal wafers). Since 1993, the production and provision of CMDs have been subject to European Union (EU) Directive 93/42/EEC (Medical Device Directive, MDD) given effect in the UK by The Medical Devices Regulations 2002 (Statutory Instrument 2002/618), and its subsequent amendments. Regulation (EU) 2017/745 (Medical Device Regulation, EU MDR) replaces the MDD and the other EU Directive pertaining to Medical Devices, Council Directive 90/385/EEC (Active Implantable Medical Device Directive, AIMDD). The EU MDR was published on 5 April 2017, came into force on 25 May 2017 and, following a three-year transition period was due to be fully implemented and repeal the MDD on 26 May 2020, but was deferred until 26 May 2021 due to the coronavirus disease 2019 (COVID-19) pandemic.In the UK, in preparation for the country's planned departure from the EU, the EU MDR, with necessary amendments, was transposed into UK law (Medical Devices (Amendment etc.) (EU Exit) Regulations 2019, UK MDR). The UK left the Union on 31 January 2020 and entered a transition period that ended on 31 December 2020, meaning that, from 1 January 2021, dental professionals in Great Britain who prescribe and manufacture CMDs are mandated to do so in accordance with the new legislation while Northern Ireland remains in line with the EU legislation and implementation date. This paper sets out the requirements that relate to the production and provision of CMDs in a UK dental setting.

A novel three-dimensional morphological analysis of idiopathic condylar resorption following stabilisation splint treatment

Bone modelling evaluation is important for monitoring idiopathic condylar resorption (ICR) progress. To compare condylar modelling in ICR patients treated with or without stabilisation splints (SSs). Eighty-four condyles from 84 ICR patients were studied: 42 received SS therapy (SS group); 42 received conventional therapy (control group). Cone-beam computed tomography images at diagnosis (T0) and after at least 6 months (T1) were used for three-dimensional reconstruction. Volume differences between T0 and T1 (δV) were used to evaluate the amount of modelling. Percentage of growth area (PCT) was used to assess the condylar surface growth tendency. No significant change in condylar volume was found in the SS group, whereas that in the control group was significantly decreased at T1 (P <.0001). The amount of modelling differed among condylar subregions within the SS group: among 6 subregions (P =.0137), between anterior and posterior regions (P =.0336) and between lateral, intermediate and medial regions (P =.0275). Control group condylar subregions showed no significant differences in the amount of modelling. The anabolic modelling tendency of the total condylar surface in the SS group was greater than that in the control group (P =.0251); however, there were no statistical differences in PCTs among condylar subregions in either group. SS therapy effectively reduced further bone destruction and promoted condylar modelling. Three-dimensional morphological analysis is a novel method that can accurately evaluate the amount of bone modelling and growth tendency in ICR patients.

Patients with epiglottic collapse showed less severe obstructive sleep apnea and good response to treatment other than continuous positive airway pressure: a case-control study of 224 patients

STUDY OBJECTIVES

The purpose of this study was to analyze patients with epiglottic collapse, especially their clinical characteristics related to obstructive sleep apnea and phenotype labeling using drug-induced sleep endoscopy.

METHODS

An age-sex matched case-control study was conducted to compare the clinical characteristics of patients with epiglottic collapse (Epi group) and patients without epiglottic collapse (non-Epi group). All patients underwent drug-induced sleep endoscopy January, 2015, to March, 2019, in a tertiary hospital for suspected sleep apnea symptoms. Demographic factors, underlying disease, overnight polysomnography, and their phenotype labeling using drug-induced sleep endoscopy were analyzed.

RESULTS

There was no difference in age, sex, the prevalence of hypertension, diabetes, cerebrovascular disease, and coronary artery disease. However, the body mass index was significantly lower in patients in the Epi group (P < .001). Additionally, the apnea-hypopnea index was lower (P = .001), and the lowest oxygen saturation was significantly higher in the Epi group (P = .042). The phenotype labeling on drug-induced sleep endoscopy showed that the prevalence of velum concentric collapse and oropharyngeal lateral wall collapse was lower, and that of tongue-base collapse was higher in the Epi group. Multilevel obstructions were more common in the Epi group. However, the Epi group showed a good response to mandibular advancement or positional therapy.

CONCLUSIONS

Although there was no difference in the underlying characteristics and self-reported symptom scores between the groups, the patients with epiglottic collapse showed significantly lower body mass index and obstructive sleep apnea severity. Additionally, patients with epiglottic collapse were expected to respond well to oral devices or positional therapy.

Can hard and/or soft occlusal splints reduce the bite force transmitted to the teeth and temporomandibular joint discs? A finite element method analysis

Objective: To test whether two different materials used for occlusal splints would reduce the stress to the temporomandibular joint discs.Methods: Geometric data from a young-adult male patient were obtained from computed tomography and magnetic resonance imaging. 3D biomodels and the finite element analyses were performed using specific software.Results: The mandibular model presented the highest bone stress areas in the mandibular rami and insertion of the temporalis muscles. Regardless the material, the highest stress in the occlusal splints was located in the second molar regions on the occlusal splint surface and in the opposing mandibular second molars. Stress reduction was only observed in the internal surface of the occlusal splints embracing the maxillary teeth. No differences between occlusal splints were found in the stress intensity and distribution in either left or right TMJ discs, being concentrated more in the anterior portion of the disc.Discussion: Hard acrylic OS should be preferred over soft EVA OS in the majority of cases, soft OS only for temporary use. Thinner OS (2-3 mm anterior thickness) should be preferred over thick ones (3-4 mm) in order to keep the stress concentrations in the center of the TMJ discs. Lighter contacts over heavier contacts should be preferred in the second molar OS contact surface area to prevent stress concentrations and fractures. Maxillary occlusal splints should be chosen if the teeth or implant are in the maxilla, and vice-versa.

Comparison of three different types of splints and templates for maxilla repositioning in bimaxillary orthognathic surgery: a randomized controlled trial

The selection and implementation of a plan for maxillary surgery is of the utmost importance in achieving the desired outcome for the patient undergoing two-jaw orthognathic surgery. Some splint-based and splintless methods, accompanied by computer-assisted techniques, are helpful in improving surgical plan implementation. However, randomized controlled trials focused on this procedure are lacking. This study included 61 patients who underwent bimaxillary surgeries. The patients were randomly assigned to a conventional resin occlusal splint (CROS) group, a digital occlusal splint (DOS) group, or a digital templates (DT) group, in a 1:1:1 ratio. The mean linear distance between the planned and actual postoperative positions of eight selected points on the surfaces of the maxillary teeth was selected as the outcome measure. The distance was significantly smaller in the DT group (1.17±0.66mm) when compared to both the CROS group (2.55±0.95mm, P<0.05) and DOS group (2.15±1.12mm, P<0.05). However, the difference between the CROS group and DOS group was not statistically significant. These findings indicate that using digital templates results in the best performance in transferring the surgical plan to the operation environment as compared to the other two types of splints. This suggests that the application of digital templates could provide a reliable treatment option.

Internet-Based Multimodal Pain Program With Telephone Support for Adults With Chronic Temporomandibular Disorder Pain: Randomized Controlled Pilot Trial

BACKGROUND

Chronic pain from temporomandibular disorders remains an undertreated condition with debate regarding the most effective treatment modalities.

OBJECTIVE

The aim of the study was to investigate the treatment effect of an internet-based multimodal pain program on chronic temporomandibular disorder pain and evaluate the feasibility of a larger randomized controlled trial.

METHODS

An unblinded randomized controlled pilot trial was conducted with 43 participants (34 females, 9 males; median age 27, IQR 23-37 years) with chronic temporomandibular pain. Participants were recruited within the Public Dental Health Service and randomized to intervention (n=20) or active control (n=23). The intervention comprised a dentist-assisted internet-based multimodal pain program with 7 modules based on cognitive behavior therapy and self-management principles. The control group received conventional occlusal splint therapy. Primary outcomes included characteristic pain intensity, pain-related disability, and jaw functional limitation. Secondary outcomes were depression, anxiety, catastrophizing, and stress. Outcomes were self-assessed through questionnaires sent by mail at 3 and 6 months after treatment start. Feasibility evaluation included testing the study protocol and estimation of recruitment and attrition rates in the current research setting.

RESULTS

Only 49% of participants (21/43) provided data at the 6-month follow-up (internet-based multimodal pain program: n=7; control: n=14). Of the 20 participants randomized to the internet-based multimodal pain program, 14 started treatment and 8 completed all 7 modules of the program. Between-group analysis showed no significant difference for any outcome measure at 3- or 6-month follow-up-characteristic pain intensity (3 months: P=.58; 6 months: P=.41), pain-related disability (3 months: P=.51; 6 months: P=.12), jaw functional limitation (3 months: P=.45; 6 months: P=.90), degree of depression (3 months: P=.64; 6 months: P=.65), anxiety (3 months: P=.93; 6 months: P=.31), stress (3 months: P=.66; 6 months: P=.74), or catastrophizing (3 months: P=.86; 6 months: P=.85). Within-group analysis in the internet-based multimodal pain program group showed a significant reduction in jaw functional limitation score at the 6-month follow-up compared to baseline (Friedman: χ2=10.2, P=.04; Wilcoxon: z=-2.3, P=.02). In the occlusal splint group, jaw function limitation was also reduced at the 6-month follow-up (Friedman: χ2=20.0, P=.045; Wilcoxon: z=-2.3, P=.02), and there was a reduction in characteristic pain intensity at the 3- and 6-month follow-up (Friedman: χ2=25.1, P=.01; Wilcoxon 3 months: z=-3.0, P=.003; Wilcoxon 6 months: z=-3.3, P=.001).

CONCLUSIONS

This study was not able to demonstrate a difference in treatment outcome between an internet-based multimodal pain program and occlusal splint therapy in patients with chronic temporomandibular pain. However, the findings suggested that the internet-based multimodal pain program improves jaw function. The results also confirmed the treatment effect of occlusal splint therapy for chronic temporomandibular pain. Furthermore, because of the high attrition rate, this pilot study showed that a randomized controlled trial with this design is not feasible.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04363762; https://clinicaltrials.gov/show/NCT04363762.

Randomized Trial of 2 Self-Titrated Oral Appliances for Airway Management

The effectiveness and predictability of 2 different oral appliance (OA) designs to reduce the respiratory event index (REI) in moderate and severe obstructive sleep apnea (OSA) patients requires elucidation. The primary aim of the trial was to determine if 2 widely used midline-traction and bilateral-thrust OA designs differ in effectiveness to reduce the REI within a single test population categorized by OSA severity. Moderate and severe adult OSA patients, who were previously prescribed continuous positive airway pressure therapy (CPAP) but were dissatisfied with it (n = 56), were studied by home-polygraphy in a randomized crossover trial using either midline-traction with restricted mouth opening (MR) or bilateral thrust with opening permitted (BP) design OAs. OAs were used nightly for 4 wk (T2) followed by a 1-wk washout period, then 4 wk (T4) using the alternate OA. REI and oxygen saturation (SaO₂) were primary outcomes, while predictability and efficacy comparison of the 2 OAs were secondary outcomes. Thirty-six participants had used MR and BP OAs during both 4-wk study legs. Twenty (55.6%) MR OA-using participants, 25 (69.4%) BP OA-using participants, and 16 (44.4%) participants using both OAs had significant REI reductions. Overall baseline (T0) median REI (interquartile range) of 33.7 (20.7-54.9) was reduced to 18.0 (8.5-19.4) at T2 and to 12.5 (8.2-15.9) at T4 (P < 0.001). Comparison of the 2 sequence groups' (MR-BP and BP-MR) REI showed the median differences between T0 and T2 and T4 were highly significant (P < 0.001). Regression analysis predicted about half of all users will have REIs between 8 and 16 after 2 mo. Baseline overjet measures >2.9 mm predicted greater OA advancement at T4. Mean and minimum SaO₂ did not change significantly from T0 to T2 or T4. MR and BP OA designs similarly attenuated REI in moderate and severe OSA individuals who completed the 8-wk study protocol with greater REI reduction in those with severe OSA (ClinicalTrials.gov NCT03219034).

Clinical Quantitative Evaluation of Tooth Wear: A 4-year Longitudinal Study

PURPOSE

This study investigated the progression of incisal tooth wear clinically for 4-years, using various diagnostic methods. Effectiveness of occlusal splints (night guards) for patients with nocturnal bruxism was also evaluated.

MATERIALS AND METHODS

Forty maxillary incisors from 10 patients with nocturnal bruxism were selected. Group 1 (n=5) wore occlusal splints for 6 months, whereas group 2 (n=5) didn't. Ultrasound, cast-model analysis (control), digital radiography, FluoreCam and colorimeter were used for measurements. Clinical progression of incisal wear monitored at baseline, 3, 6, 12, 24 and 48 months, respectively.

RESULTS

Ultrasound, cast-model analysis and FluoreCam readings gradually and statistically significantly decreased during the overall evaluation period for both groups (p<0.001). Regarding colorimeter, statistically significant differences in periodical measurements were observed from 24 months and 12 months, for group 1 and group 2, respectively (p<0.001). There were no statistically significant differences in readings at evaluation periods, between the groups, for ultrasound, digital radiography and cast-model analysis (p≥0.05); however, statistically significant differences were observed for colorimeter at 24 months (p=0.010) and 48 months (p<0.001), and for FluoreCam at 12, 24, 48 months (p<0.001). Annual decrease in mean crown length was determined as 20-30 µm for group 1 and 40-50 µm for group 2. The decreases in mean crown length were statistically significantly lower for group 1 compared to group 2, regarding the assessments for 1 year, 2 years and 4 years (p<0.001). Positive and good correlations were observed between ultrasound, cast-model analysis and FluoreCam measurements (p<0.001).

CONCLUSIONS

Ultrasound, FluoreCam and colorimeter showed promising results for monitoring any change and progression of incisal tooth wear clinically. Ultrasound might be considered as a quantitative, reliable and repeatable method. Precision of the measurements varied among the diagnostic methods used. Occlusal splints may have a potential preventive effect for progressive tooth wear.

Over-the-counter bite splints: A randomized controlled trial of compliance and efficacy

Background

Occlusal splints are often used to curb the impacts of sleep bruxism (SB) on the dentition, and over‐the‐counter (OCT) options are becoming increasingly popular. OTC splints are usually fabricated at home by patients, but not routinely evaluated by dental professionals. It is unclear how OCT splints compare with more traditional splints that receive dental oversight.

Objectives

The present randomized controlled study tested how an OTC splint compared with a gold standard bite splint in terms of patient compliance (primary outcome) and efficacy (secondary outcomes).

Methods

Sixty‐seven subjects were randomly assigned to receive either the OTC (SOVA, N = 35) splint or the gold standard “Michigan” bite splint (MI, N = 32), with 61 completing the study (SOVA, N = 30; MI, N = 31). OTC‐splint subjects were required to fabricate their splints to clinically acceptable standards. Both groups wore the splints nightly for four months. Compliance was measured via daily diary. Efficacy outcomes evaluated stability, retention, periodontal health, night‐time rhythmic masticatory muscle activity (RMMA), and material wear.

Results

OTC‐splint subjects had difficulty fabricating splints to clinically acceptable standards. The number of night‐time RMMA bursts was significantly greater for the OTC splint group. Compliance and all other efficacy measurements were not significantly different between‐groups.

Conclusions

The results support the potential use of OTC splints for curbing the impacts of SB. However, the results strongly suggest that dentists should be actively engaged in overseeing patients' use of self‐fabricated appliances. This clinical trial is registered at ClinicalTrials.gov, Identifier number NCT02340663.

Treatment of myofascial pain with a rapid laser therapy protocol compared to occlusal splint: A double-blind, randomized clinical trial

OBJECTIVE

To compare the effect of a rapid low-level laser therapy (LLLT) protocol to Michigan occlusal splint in the treatment of myofascial pain, as well as to evaluate their impact on Oral Health-Related Quality of Life (OHRQoL).

METHODS

Thirty participants were randomly allocated into three groups: G1: occlusal splint (n = 11), G2: LLLT (n = 10), and G3: LLLT placebo (n = 9). LLLT and placebo were applied in the points of pain upon palpation.

RESULTS

G1 presented improvement in pain (p = 0.014) and in the diagnosis of myofascial pain (p = 0.008), while G2 and G3 did not. Regarding OHRQoL, G1 and G2 presented significant improvement (p = 0.005, in both), whereas, G3 did not.

CONCLUSION

Michigan occlusal splint was effective in reducing pain and improving OHRQoL. Treatment with the rapid LLLT protocol only provided an improvement in OHRQoL.

The effectiveness of stabilization appliance therapy among patients with myalgia

BACKGROUND

The efficacy of stabilization appliance therapy for masticatory muscle pain is debated. Therefore, there are currently no clear usage standards. We analyzed patient factors influencing its efficacy and characterized masticatory muscle pain subtypes to determine appropriate therapy candidates.

METHODS

This case series study recruited patients diagnosed with local myalgia or myofascial pain and used variables related to temporomandibular disorders in the analysis. We used temporary appliance to screen patients for sleep bruxism for 2 weeks. Afterwards, we initiated therapy with stabilization appliances. Efficacy was evaluated via tenderness intensity during muscle palpation and the treatment satisfaction score after 2 months of treatment.

RESULTS

We analyzed 62 (91%) patients. Tenderness upon muscle palpation was mitigated in 27 patients. Mitigated tenderness odds ratios were 0.035 for myofascial pain, 0.804 for 15-item Patient Health Questionnaire scores, and 1.915 for facet length. Thirty-nine patients expressed satisfaction; satisfaction odds ratios were 0.855 for 9-item Patient Health Questionnaire scores, 1.606 for facet length, and 4.023 for awake bruxism awareness.

CONCLUSIONS

Stabilization appliance therapy is most effective for patients with awake bruxism awareness, local myalgia, long facets, and no psychosocial risk factors.

Treatment of Somatosensory Tinnitus: A Randomized Controlled Trial Studying the Effect of Orofacial Treatment as Part of a Multidisciplinary Program

Background: Tinnitus, or ringing in the ears, is a perception of sound in the absence of overt acoustic stimulation. In some cases, tinnitus can be influenced by temporomandibular somatosensory input, then called temporomandibular somatosensory tinnitus (TST). It is, however, not entirely known if orofacial treatment can decrease tinnitus severity. The purpose of this study was to evaluate the effect of orofacial treatment on tinnitus complaints in patients with TST. Methods: Adult patients with TST were included, and all patients received information and advice about tinnitus and conservative orofacial treatment consisting of physical therapy, and, in case of grinding, occlusal splints were applied. Included patients were randomly assigned to an early start group and a delayed start group according to our delayed treatment design. Results: In total, 40 patients were included in each group. The treatment effect on tinnitus severity was investigated using the tinnitus questionnaire (TQ) and Tinnitus Functional Index (TFI). Regarding the TQ score, no clinically relevant reductions were observed, and no significant differences in the decrease were observed between the early start group and delayed start group. Contrarily, a significantly higher percentage of patients showed a decrease in the TQ degree in the early start group compared to the delayed start group (30.0% versus 2.8%, p = 0.006). The TFI score did show a significantly greater and clinically relevant reduction in the early start group compared to the delayed start group (p = 0.042). Conclusion: A multidisciplinary non-invasive orofacial treatment was able to reduce tinnitus severity in patients with temporomandibular related somatosensory tinnitus.

A kinematic analysis on the immediate effects of occlusal splints in gait and running body sway patterns

Objective: This study aims to determine whether changes in dental occlusion are correlated to body posture during walking and running.Methods: Fifteen healthy subjects were assessed by a prosthodontist and deemed asymptomatic. Analyses of gait and running were performed in three conditions, in random order: a) occlusal splint; b) placebo splint; and c) no splint. The occlusal splint used in this study positioned the mandible in a stable position. Kinematic data was collected using a 3D motion capture system.Results: Changes in dental occlusion induced by occlusal splints did not influence body sway during gait or running. No significant differences were found between any of the test conditions.Conclusion: Occlusal splints have no effect on body sway during gait or running. High inter-subject variability in kinematic parameters was found, which should be considered in future studies.

Quantification of the inaccuracy of conventional articulator model surgery in Le Fort 1 osteotomy: evaluation of 30 patients controlled by the Orthopilot® navigation system

Occlusal splints are commonly used to position the maxilla during traditional orthognathic surgery. We aimed to quantify the inaccuracy of the maxillary positioning (in three dimensions) in traditional model surgery with the Orthopilot^® navigation system. Thirty Le Fort I osteotomies were made using a standard technique. The position of the maxilla was recorded by the navigation system and defined by three values of translation and three of rotation. The recorded data were compared with the planned data. The accuracy of positioning was classified in distinct classes with three major criteria (conformity, non-conformity, and failure) according to the discrepancy. The positioning of the maxilla was in conformity with operative planning in 3/30 of our Le Fort I osteotomies (95% CI 2% to 27%) and in failure in 22/30 (95% CI 54% to 88%). The dispersion of the discrepancy was more important in the sagittal plane, particularly for the sagittal rotation and for the back-front translation, which reflected greater inaccuracy in this plan. The frontal orientation of the maxilla was better controlled. The risk of maxillary malposition was proportional to the planned maxillary advancement.

Effect of occlusal splint and therapeutic exercises on postural balance of patients with signs and symptoms of temporomandibular disorder

The aim of this study was to investigate the effects of the use of an occlusal splint on postural balance considering the occlusal splint as a device for treating temporomandibular joint disorder. A randomized, controlled, prospective clinical trial was conducted. The research group consisted of 49 patients (36 as test group and 13 as control group) between 18 and 75 years old, both genders, diagnosed as temporomandibular disorder by Research Diagnostic Criteria/Temporomandibular Disorders questionnaire and magnetic resonance imaging of the temporomandibular joints. Test group was treated with orientations for physiotherapeutic exercises and occlusal splint, whereas control group received orientation for physiotherapeutic exercises only. Postural equilibrium was evaluated by means of a force plate. After 12 weeks, the groups were re-evaluated. Patients from both groups presented a significant increase in antero-posterior speed with eyes closed, test group (P < 0.001) and control group (P = 0.046). Only patients of the test group presented a significant increase in antero-posterior speed with eyes opened (P = 0.023). We concluded that the use of occlusal splint affected the postural balance.

Occlusal Splints and Periodontal/Implant Therapy

BACKGROUND

Occlusal trauma, defined as an injury to the tooth or implant supporting tissues, is a resultant of parafunctional habits such as bruxism. It has been shown to accelerate periodontal breakdown and also contribute to implant complications, thereby adversely affecting the long-term success of periodontal and implant therapy. This review aims to discuss the effects of bruxism on periodontal and implant treatment. In addition, the effectiveness of occlusal splints to manage bruxism will be examined.

METHODS

An electronic literature search using PubMed and Scopus databases and a manual search for relevant papers published in English from January 1965 up to August 2017 was performed..

RESULTS

An occlusal splint appears to be effective in reducing symptoms related to temporomandibular disorder and bruxism. However, high quality evidence is severely lacking to support its use. Therefore, as it is a non-invasive and reversible therapy, its use in patients with bruxism is proposed.

CONCLUSIONS

Therefore, as it is a non-invasive and reversible therapy, occlusal splint use in patients with bruxism is proposed.

[The need for specific toothpaste in patients receiving occlusal splint therapy]

The aim of the study is to determine the optimal properties of toothpaste for patients receiving occlusal splint therapy. The study comprised 50 people with full dentition (21 male and 29 female) divided into two groups. The main group included 25 individuals receiving occlusal splint therapy while 25 people who did not use splints were recruited as controls. Each group was further divided into two subgroups according to toothpaste used for regular oral hygiene. Examinations were performed after 14, 30 and 90 days using hygienic indices of NCI-C and Turesky and PMA gingival index. The combined effect of toothpaste was estimated by the change in the volume and acidity of saliva. The results suggest a better level of hygiene in the group I, which used toothpaste with sodium bicarbonate and silica.

Utility of facebow in the fabrication of complete dentures, occlusal splints and full arch fixed dental prostheses: A systematic review

OBJECTIVE

The objective of this study is to assess the utility of facebow transfer in the fabrication of occlusal splints, complete dentures and full arch fixed dental prosthesis.

MATERIALS AND METHODS

A systematic review protocol was registered at PROSPERO registry, University of York, UK (CRD42016041919). Following databases were explored: PubMed, CINAHL, Cochrane, and Web of knowledge. The PICO model included participants who received occlusal splint or complete denture or full arch fixed dental prosthesis at the centric relation position. The intervention was the use of facebow transfer. Comparators were prosthesis made without using a facebow. Outcomes were the patient satisfaction of the prosthesis and the need for laboratory adjustments. Only randomized clinical trials were included in the present review. A customized data extraction pro forma was used to extract the data and assess its quality.

RESULTS

A total of 505 articles were retrieved. On excluding duplicates, protocols, case reports, case series, narrative reviews, etc., only eight studies were selected for review. Six clinical trials on 249 complete dentures and two clinical trials on 65 occlusal splints were reviewed. No study on full arch crown and bridge work satisfied the inclusion criteria.

CONCLUSIONS

The use of facebow did not yield a superior fit or comfort of the complete dentures or occlusal splints. Therefore, there is no evidence of the utility facebow transfer for these prostheses. However, no inference could be drawn for its utility in full arch fixed dental prosthesis as there were no studies to draw an inference.

Management of pain in TMD patients: Bio-oxidative ozone therapy versus occlusal splints

OBJECTIVE

To compare the effects of bio-oxidative ozone application with occlusal splints in temporomandibular disorder (TMD) patients with pain.

METHODS

Forty participants were selected after the diagnosis of TMD and randomly divided into two groups: ozone group (OG, n = 20) and occlusal splint group (OCSG, n = 20). Ozone was applied to patients three times per week, for a total of six sessions. Patients in the OCSG were instructed to use occlusal splints every night over a period of four weeks.

RESULTS

Mandibular movements showed significant differences for the time factor in OG and OCSG. Pressure pain thresholds of the temporal and masseter muscles at follow-up were significantly higher in the OCSG group. Both treatments statistically decreased the visual analog scale (VAS) scores. However, no statistically significant difference was observed between groups after the application of treatments.

DISCUSSION

Occlusal splint treatment is still the gold treatment modality for objective pain relief in patients with TMD pain.

A progressive approach for the use of occlusal devices in the management of temporomandibular disorders

Temporomandibular disorders (TMDs) represent a broad spectrum of conditions associated with the temporomandibular joints and the neuromuscular system. Evidence-based diagnostic criteria for various TMDs are emerging, while corresponding treatment procedures remain less clear. As a result, the clinician may be uncertain how to best care for TMD patients. The objectives of this evidence-based review were to outline the various types of occlusal devices, assess the efficacy of occlusal splints in treating TMD patients, and create a treatment rubric based on diagnostic criteria and condition severity. A select literature review as to the effectiveness and efficacy of occlusal device TMD therapy revealed that stabilization splint intervention and control treatments had a positive effect in reducing TMD-related symptoms; minimal statistically significant differences were noted between intervention and control treatments. Stabilization splints are effective as a reversible treatment for patients with TMD. Other therapies and occlusal devices may be beneficial when used for a specific TMD diagnostic protocol. A treatment rubric based on diagnostic criteria and condition severity may assist the clinician.

Comparison of three different options for immediate treatment of painful temporomandibular disorders: a randomized, controlled pilot trial

OBJECTIVE

The purpose of this study was to compare the short-term effectiveness of three different types of immediate, non-pharmacological intervention for alleviation of the painful symptoms of temporomandibular disorders (TMD).

MATERIAL AND METHODS

Thirty-six patients (mean age 41.6 ± 16.7 years, 25 females) diagnosed with non-dysfunctional painful TMD received counselling and subsequently were randomly allocated to three treatment groups: patients in Group A received prefabricated oral splints with water-filled elastic pads (Aqualizer(®)), those in Group B were provided with vacuum-formed co-polyester oral splints and those in Group C were given appointments to receive Michigan-type hard splints. Clinical examination was conducted, at baseline and after 2 weeks, by use of the RDC/TMD. Current pain intensity was determined by evaluation of graded chronic pain status (GCPS) on a numerical rating scale (NRS). Active maximum mouth opening without pain (AMMOP) was also measured. Paired sample t-tests and one-way analysis of variance with a significance level of p ≤ 0.05 were conducted.

RESULTS

After 2 weeks, overall mean current pain was reduced by 41.95% (p < 0.001). Current pain reduction was significant for Group B (66.6%, p < 0.001) but not for Groups A (37.88%, p = 0.56) and C (22.29%, p = 0.26). After 2 weeks, current pain level for Group B was significantly lower than that for Group C (p = 0.041). Overall, there was a statistically significant increase of AMMOP (p = 0.01).

CONCLUSION

All therapeutic options were pain-reducing. The results from this study suggest that cost-effective and time-effective intervention of counselling combined with use of a vacuum-formed splint is a favourable option for initial, short-term treatment of painful TMD.

Comparative evaluation of clinical performance of different kind of occlusal splint in management of myofascial pain

Purpose:

To determine the efficacy of hard, liquid, and soft splints in the management of myofascial pain dysfunction syndrome.

Materials and Methods:

In this randomized clinical trial, 45 patients with myofascial pain were diagnosed and were randomly assigned into three groups of 15 patients each. Group 1 - subjects were given hard splint, Group 2 - soft splint, and Group 3 - liquid oral splint for 3 months. Subjective pain analysis using Modified Symptom Severity Index (Mod-SSI) and objective pain analysis muscle palpation was performed at 7 days, 1 month, 2 months, and 3 months after splint insertion. The changes in mean pain value by both methods, in all three groups, were analyzed with Tukey test and Kruskal–Wallis H-test, respectively (P < 0.05).

Results:

Both Mod-SSI and palpation scores showed statistically significant reduction in pain for all three groups at the end of 3 months. However, the hard splints proved to be very effective in a shorter period of time, followed by liquid splints and finally soft splints.

Conclusion:

The result of this study advocates the use of any one of the three types of the occlusal splints in the therapeutic management of myofascial pain due to temporomandibular disorders.

Small vertical changes in jaw relation affect motor unit recruitment in the masseter

Strategies for recruitment of masseter muscle motor units (MUs), provoked by constant bite force, for different vertical jaw relations have not previously been investigated. The objective of this study was to analyse the effect of small changes in vertical jaw relation on MU recruitment behaviour in different regions of the masseter during feedback-controlled submaximum biting tasks. Twenty healthy subjects (mean age: 24·6 ± 2·4 years) were involved in the investigation. Intra-muscular electromyographic (EMG) activity of the right masseter was recorded in different regions of the muscle. MUs were identified by the use of decomposition software, and root-mean-square (RMS) values were calculated for each experimental condition. Six hundred and eleven decomposed MUs with significantly (P < 0·001) different jaw relation-specific recruitment behaviour were organised into localised MU task groups. MUs with different task specificity in seven examined tasks were observed. The RMS EMG values obtained from the different recording sites were also significantly (P < 0·01) different between tasks. Overall MU recruitment was significantly (P < 0·05) greater in the deep masseter than in the superficial muscle. The number of recruited MUs and the RMS EMG values decreased significantly (P < 0·01) with increasing jaw separation. This investigation revealed differential MU recruitment behaviour in discrete subvolumes of the masseter in response to small changes in vertical jaw relations. These fine-motor skills might be responsible for its excellent functional adaptability and might also explain the successful management of temporomandibular disorder patients by somatic intervention, in particular by the use of oral splints.

Spontaneous neural activity alterations in temporomandibular disorders: a cross-sectional and longitudinal resting-state functional magnetic resonance imaging study

The involvement of the central nervous system in the pathophysiology of temporomandibular disorders (TMD) has been noticed. TMD patients have been shown dysfunction of motor performance and reduced cognitive ability in neuropsychological tests. The aim of this study is to explore the spontaneous neural activity in TMD patients with centric relation (CR)-maximum intercuspation (MI) discrepancy before and after stabilization splint treatment. Twenty-three patients and twenty controls underwent clinical evaluations, including CR-MI discrepancy, Helkimo indices and chronic pain, and resting state functional magnetic resonance imaging scans at baseline. Eleven patients repeated the evaluations and scanning after the initial wearing (T1) and 3months of wearing (T2) of the stabilization splint. The fractional amplitude of low-frequency fluctuation (fALFF) was calculated to compare the neural functions. At baseline, the patients showed decreased fALFF in the left precentral gyrus, supplementary motor area, middle frontal gyrus and right orbitofrontal cortex compared with the controls (P<0.05, AlphaSim corrected). Negative correlations were found between the fALFF in the left precentral gyrus and vertical CR-MI discrepancy of bilateral temporomandibular joints of patients (P<0.05, two-tailed). At T2, the symptoms and signs of the patients were improved, and a stable condylar position on the CR was recovered, with increased fALFF in the left precentral gyrus and left posterior insula compared with pretreatment. The fALFF decrease in the patients before treatment was no longer evident at T2 compared with the controls. The results suggested that TMD patients with CR-MI discrepancy showed significantly decreased brain activity in their frontal cortexes. The stabilization splint elicited functional recovery in these cortical areas. These findings provided insight into the cortical neuroplastic processes underlying TMD with CR-MI discrepancy and the therapeutic mechanisms of stabilization splint.

Precision occlusal splints and the diagnosis of occlusal problems in myogenous orofacial pain patients

Myogenous orofacial pain is a common nondental pain. There is an unresolved debate on the etiology of this problem. Research has shown that occlusal interferences affect masticatory muscle comfort, coordination, and function. Resolution of these problems with precise occlusal correction indicates that dental occlusion is a causative or contributory factor in myogenous orofacial pain. However, some studies fail to confirm this and instead conclude that occlusion is unrelated to masticatory muscle pain or dysfunction. An explanation for this discrepancy in findings is that these nonconfirmatory studies had not documented any pretreatment or corrected occlusion. Diagnostic casts mounted in centric relation and precision occlusal splints are accurate modalities to diagnose the occlusal problem and its correction in a patient with myogenous orofacial pain. Computerized digital occlusal analysis provides objective data of occlusal contact time and force to accurately assess diagnosis and treatment. The rationale and requirements for proper occlusal splint fabrication with a verified therapeutic occlusion are presented.

Oral splint for temporomandibular joint disorders with revolutionary fluid system

Temporomandibular joint (TMJ) diseases and disorders refer to a complex and poorly understood set of conditions, manifested by pain in the area of the jaw and associated muscles and limitations in the ability to make the normal movements of speech, facial expression, eating, chewing, and swallowing. The conventional soft occlusal splint therapy is a much safer and effective mode of a conservative line of therapy in comparison to the surgical therapy for temporomandibular joint disorders (TMD). The purpose of this article is to review the Aqualizer™, an hydrostatic oral splint, as accurate, effective treatment and differential diagnostic tool in TMD that allow treating the patient's pain quickly and accurately saving valuable treatment time. The review article has been prepared doing a literature review from the world-wide web and pubmed/medline.

Surgical management of oral submucous fibrosis in an edentulous patient: A procedural challenge

Prosthetic rehabilitation of patients with oral submucous fibrosis (OSMF) offers a formidable challenge due to restricted mouth opening. Physiotherapy via interocclusal force application is the mainstay for surgical treatment. Herein, we report a case of a man with OSMF requiring construction of dentures. The main objective was to deliver intra-operative and post operative inter occlusal forces without fracturing the mandible and thus providing rehabilitation to the patient prosthetically. An edentulous male patient reported with grade IVA OSMF to our department to improve his mouth opening for denture construction. The patient was managed successfully using surgical sectioning of the fibrous bands. Inter occlusal force application for mouth opening during the operation and post operative physiotherapy were facilitated using custom-made occlusal splints. Satisfactory mouth opening was achieved, with good healing and no event of infection or fracture. Here, we propose an easy method to achieve adequate mouth opening in an edentulous patient of OSMF, with atrophic ridges; without the chances of fracture of either jaw.

Postsurgical Orthodontic Treatment Planning: a Case Report with 20 Years Follow-up

Background

Traditionally, maxillofacial deformities are corrected surgically after an initial orthodontic treatment phase. However in, this article, the authors emphasize the postsurgical therapeutic protocol which is extremely important for determining the final and permanent retention of the corrected occlusion.

Methods

A 55 year old female with severe skeletal Class II malocclusion is presented. Combined surgical and orthodontic correction of the malocclusion was used.

Results

: The step-by-step procedure the authors followed for the postsurgical therapy is described. The goals of the postoperative therapy were to restore and rehabilitate neuromuscular function, obtain occlusal stabilization, grind teeth selectively, and final occlusion retention. The importance of a surgical occlusal splint for rehabilitating stomatognathic neuromuscular function postoperatively was demonstrated. Furthermore, the orthodontic-prosthodontic treatment ensured occlusion stability after the surgical correction. The long-term results confirmed the efficacy of the treatment protocol presented here from both functional and aesthetical perspectives.

Conclusions

Postsurgical orthodontic treatment is an important step in the surgical and orthodontic therapy of maxillofacial deformities.