A comparative study of audiology and cone beam computed tomography in TMD patients with otological symptoms through occlusal splint therapy

INTRODUCTION

To investigate the changes of audiological tests and the cone beam computed tomography (CBCT) measurements of temporomandibular joint (TMJ) and middle-inner ear structure after occlusal splint therapy in temporomandibular disorders (TMD) patients with otological symptoms, and explore the etiological mechanism between TMD and otological symptoms.

METHODS

The 25 subjects aged 18 to 40 years who diagnosed with TMD combined the otological symptoms enrolled in the study.They all had received orthodontic treatment in the outpatient clinic of the orthodontic department in Beijing Stomatological Hospital. All the subjects underwent the audiological tests of pure tone audiometry (PTA) and CBCT before and after the occlusal splint therapy.

RESULTS

After the stabilization occlusal splint therapy, subjects with improvement or complete remission in TMD and otological symptoms accounted for 84% and 80% in all subjects respectively. There were statistically differences in the distances between condylar center (CoC) and sella (S) in sagittal and vertical directions before and after treatment, and statistically difference between ATM and S in sagittal direction. The threshold of PTA at 8000Hz were negatively correlated with the sagittal displacement of condyle and positively correlated with the coronal displacement of condyle. The thickness of top 1/3 of anterior wall of tympanum in sagittal were positively correlated with the threshold of PTA at 4000Hz.

CONCLUSION

The changes in the TMJ position through occlusal splint therapy might cause the changes in structure of middle-inner ear, which might be one of the reasons for the improvement in otological symptoms.

KEY WORDS

Audiology, CBCT, Otological symptoms, TMD.

Mandibular Advancement Splint Therapy

Mandibular advancement splint (MAS) therapy is the leading alternative to continuous positive airway pressure (CPAP) therapy for the treatment of obstructive sleep apnoea. A MAS is an oral appliance which advances the mandible in relation to the maxilla, thus increasing airway calibre and reducing collapsibility. Although it is less effective than CPAP in reducing the apnoea-hypopnoea index (AHI), it has demonstrated equivalence to CPAP in a number of key neurobehavioural and cardiovascular health outcomes, perhaps due to increased tolerability and patient adherence when compared to CPAP. However, response to MAS is variable, and reliable prediction tools for patients who respond best to MAS therapy have thus far been elusive; this is one of the key clinical barriers to wider uptake of MAS therapy. In addition, the most effective MAS devices are custom-made by a dentist specialising in the treatment of sleep disorders, which may present financial or accessibility barriers for some patients. MAS devices are generally well tolerated but may have side effects including temporomandibular joint (TMJ) dysfunction, hypersalivation, tooth pain and migration as well as occlusal changes. A patient-centred approach to treatment from a multidisciplinary team perspective is recommended. Evidence-based clinical practice points and areas of future research are summarised at the conclusion of the chapter.

Long-term adherence to oral stabilization splints: does pain matter?

OBJECTIVE

Occlusal stabilization splints (OSSs) are first-line therapy for temporomandibular disorder (TMD) and sleep-related-bruxism (SRB). The main goal of this study was to quantify adherence rates to OSS therapy in TMD patients and among non-painful conditions such as clenching and bruxism. It was hypothesized that adherence rates would be similar to those for other chronic conditions.

METHOD AND MATERIALS

Medical records of 99 patients seen in the Orofacial Pain Clinic between 2006 and 2014 were reviewed. Patients meeting the inclusion criteria were interviewed over the telephone regarding OSS adherence.

RESULTS

Of the 99 patients interviewed, 80 had chronic orofacial pain related to TMD and 19 received OSS due to (non-painful) SRB. Patients were divided according to usage; the USER group (58 patients, 58.6%) used their OSS for more than 1 year; the NUSE group was the remaining 41 (41.4%) patients who used their device for less than 1 year. Of the patients with pain as the reason for OSS use, 50 (62.5%) were in the USER group and 30 (37.5%) were in the NUSE group. The most common diagnosis was masticatory muscle disorders (MMD) with a 71.4% adherence rate, representing 60.3% of the USER group, which was significantly higher than those with SRB and other facial pain (P = .039). The most common reasons for non-adherence were sleep difficulties with OSS (31.6%) and resolution of the problem (25%).

CONCLUSIONS

Patients reporting mild to major pain reduction had higher adherence rates than those with complete pain relief or none at all. Patients with MMD exhibited higher adherence rates than those with other facial pain types and SRB.

Bruxist Activity Monitor System (BAMS): An instrumental approach tool in the assessment of Bruxism

The magnitude of harmful effects on dental structures, periodontium, masticatory muscles, and the temporomandibular joint, derived from temporomandibular disorders, specifically from sleep Bruxism, generates evidence that needs to be objectively collected. This paper introduces a portable device aiming at extracting and analyzing parameters (like timestamp, duration, or latency) from recordings obtained from the monitoring of occlusal activity, throughout a complete sleep cycle. An electronic device embedded in a mid-density medical grade silicon occlusal splint detects the moment in which the subject exerts sustained force, and records the time and length of the event, keeping the device on hold until a new event arises. The electronic device, based on a microcontroller, identifies occlusive events from an array of two piezo-resistive sensors and has a storage capacity of up to 36 hours of continuous activity. The collected data is wirelessly transmitted to an external module that is connected via USB to a PC. In the PC, the data is decoded, processed, analyzed, displayed, and stored in ordered files for case subjects, updating every recorded test for a complete history review. The proposed Bruxist Activity Monitor System (BAMS) was tested in one subject for more than 40 hours (5 sessions in 7 days). Preliminary results show the oral appliance endure without any significant damage over its surface nor undermining its functionality.

Occlusal Splints and Exercise Performance: A Systematic Review of Current Evidence

The role of the dento-mandibular apparatus and, in particular, occlusion and jaw position, received increased attention during last years. In the present study, we aimed to systematically review, on the light of the new potential insights, the published literature covering the occlusal splint (OS) applications, and its impact on exercise performance. A structured search was carried out including MEDLINE^®/PubMed and Scopus databases with additional integration from external sources, between March and June 2021. To meet the inclusion criteria, studies published in the English language, involving humans in vivo, published from 2000 to 2021 and that investigated the role of occlusal splints on athletes' performance were selected. Starting from the 587 identified records, 17 items were finally included for the review. Four main aspects were considered and analyzed: (1) occlusal splint characteristics and occlusion experimental conditions, (2) jump performance, (3) maximal and explosive strength, and (4) exercise technique and biomechanics. The results of the systematic literature analysis depicted a wide heterogenicity in the experimental conditions and suggested the application of the OS as a way to improve athletes' or individuals' oral health, and as a potential tool to optimize marginal aspects of exercise performance.

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.

Influence of Flat Occlusal Splint on Stresses Induced on Implants for Different Fixed Prosthetic Systems

OBJECTIVE

The flat occlusal plate has been recommended to reduce stress concentration in implant prosthesis treatments. The purpose was to investigate the influence of the occlusal splint on three-element implant-supported fixed prosthesis.

MATERIALS AND METHODS

A three-dimensional virtual model was created consisting of a cortical and spongy bone block simulating the region from first premolar to the maxillary first molar using two HE or MT implants (4 x 11mm) with Ti and/or Y-TZP abutments. The second premolar was the pontic of the prosthesis. The three-element fixed prosthesis with a zirconia infrastructure and Y-TZP coating were cemented, in addition to using a flat occlusal splint made of acrylic resin in the region. Combined axial and oblique loads of 100N and 300N were applied.

RESULTS

The tensile stresses on MT implant bone tissue produced values of 4-19% lower than those of HE implants. The lowest differences were observed for oblique loading with an occlusal splint, with a 4% (Ti-Y-TZP) and 9% (Ti-Ti) decrease. When the compressive stresses were evaluated, HE implants produced lower values than MT implants.

CONCLUSION

A significant increase was observed in the oblique loading stresses in the absence of occlusal splints, regardless of the applied load.

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.

Effects of Different Therapeutic Modalities on the Clicking Sound and Quantitative Assessment of the Vertical and Lateral Mandibular Movements of Patients with Internal Derangements of the Temporomandibular Joint

PURPOSE

To compare the efficacy of low-dose laser therapy to that of conservative treatment using two different occlusal splints (stabilization and anterior repositioning splints) in patients with internal derangements of the temporomandibular joint (TMJ).

MATERIALS AND METHODS

The study population consisted of patients with disc displacement with reduction diagnosed according to the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) Axis I and Axis II. In addition, disc displacement with reduction was confirmed in all patients using TMJ ultrasonography. These tests were conducted for 6 months with an interim control in the third month. The "clicking" sound from the joint on opening and closing the mouth and the extent to which the mouth opened vertically and laterally were assessed. In all, 20 patients received low-dose laser therapy, 20 were treated with a stabilization splint, and 20 were treated with an anterior repositioning splint. In addition, 10 untreated patients were included as a patient control group, and a further 10 healthy subjects were included as a healthy control group. Changes in the condition were assessed based on the results of the RDC/TMD Axis II and with the use of an algometer.

RESULTS

The anterior repositioning splint group showed improvement in the "clicking" sound during mouth opening. Lateral movement improved significantly in patients who received laser therapy. In the patient control group, the click disappeared during mouth opening, the algometrically determined pain improved, and the lateral movement increased. There were no statistically significant differences between groups in the improvement of vertical mouth movement or in the clicking sound during mouth closing.

CONCLUSION

Each treatment modality applied in this study separately produced positive results for the clicking sound, restrictions in vertical and lateral movements, and reduction of the pressure pain threshold observed in cases of TMJ irregularity. The decision regarding which treatment modality should be employed can be made based on the patient's symptoms. However, this study also indicates that TMJ derangements can resolve spontaneously when left untreated.

[Clinical study of modified posterior dental splint in the treatment of anterior disk displacement without reduction of the temporomandibular joint]

PURPOSE

To investigate the clinical effect of modified posterior dental splint in the treatment of anterior disk displacement without reduction of the temporomandibular joint (TMJ).

METHODS

Eight-nine patients with anterior disk displacement without reduction of the TMJ who were treated in Stomatology Hospital of Guangzhou Medical University from October 2016 to October 2017 were selected in the study. 47 patients in the first group were treated by modified posterior dental splint, while 42 patients in the second group were treated by stabilization splint. The patients' pain index, mouth opening degrees were collected before treatment,3 months, 6 months, and 1 year after treatment. Statistical analysis of the data was performed using SPSS 18.0 software package, multivariate test was used to compare the indicators between the two groups.

RESULTS

The effect of modified posterior dental splint on treating limited mouth opening was better than those of stabilization splint(P<0.05). In the treatment of joint pain, the two splints had no significant difference(P>0.05).

CONCLUSIONS

Modified posterior dental splint is a new type of splint for the treatment of TMJ disorders. It is suitable for clinical application.

Smart Mandibular Advancement Device for Intraoral Monitoring of Cardiorespiratory Parameters and Sleeping Postures

Obstructive sleep apnea (OSA), as a highly prevalent sleep disorder, causes several serious health complaints. It has been proved that using intraoral mandibular advancement devices (MADs) during sleep is an efficient treatment for OSA. However, due to limited number of sleep study laboratories, effectiveness of MAD therapy is not regularly monitored. This paper proposes a smart MAD with the capability of continuously monitoring of cardiorespiratory parameters as well as sleeping postures and breathing routes. In this regard, a flexible hybrid wireless sensing platform based on the intraoral photoplethysmography (PPG), temperature and accelerometry monitoring is developed. It is qualitatively and quantitatively discussed that the intraorally captured PPG signals by the smart MAD have similar features as the ones received from the conventional anatomical position, i.e., the left index fingertip. Extensive experimental measurements indicate that the proposed smart MAD can estimate heart-rate (HR), respiration rate (RR) and blood oxygen saturation (SpO₂) with the maximum mean-absolute-errors of 2.4 bpm, 2.52 breaths/min, and 0.8%, respectively, in comparison to the reference measurements, while such a capability is not dependent on subject's positions and breathing routes. It is also shown that the smart MAD can readily identify different sleeping postures, namely, supine, left, right, and prone and breathing routes. The reliability and stability of the proposed smart MAD's measurements are proved by examining a group of subjects. The proposed smart MAD has potential to monitor the effectiveness of MAD treatment and eliminate untreated OSA without the requirement of attaching an extra monitoring platform to the patient's body.

Occlusal devices in France: An assessment of professional practice

STATEMENT OF PROBLEM

Whether recommendations for the use of occlusal devices are made uniformly in terms of indications, designs, and wearing time is unclear. Different recommendations may lead to different clinical outcomes.

PURPOSE

The purpose of this survey was to assess the professional practice of dental surgeons in France regarding the use of occlusal devices.

MATERIAL AND METHODS

A 26-question cross-sectional survey was sent to a panel of French dentists via the County Councils of the Dental Order. The questionnaire concerned the amount of occlusion-related treatment, the use of an anterior deprogramming device, stabilization splint, and anterior repositioning appliance, and the patient follow-up as well as the drawbacks of using an occlusal device as a therapeutic solution. The statistical tests used in the study were the chi-square test and the Yate correction for continuity.

RESULTS

A total of 771 responses were received. Invasive options were still reported as being used as a first-line treatment for temporomandibular disorder, although a statistical difference was found between experienced and recently graduated practitioners, with recent graduates preferring noninvasive options as first-line treatment. Also, the results showed that anterior deprogramming devices were not used or that their application, particularly the length of treatment, was unfamiliar to practitioners. The anterior repositioning appliance seems to be used, but only a few practitioners integrate it into their practice. In general, about one-third of dentists appear to have a good knowledge of occlusion-related treatments, in particular, the use of occlusal devices.

CONCLUSIONS

The results indicated that only 20% to 30% of practitioners have good knowledge of contemporary occlusion-related practice. There is a need for the standardization of practice and improved education for practitioners in the use of occlusal devices.

Functional Upper Airway Space Endoscopy: A Prognostic Indicator in Obstructive Sleep Apnea Treatment with Mandibular Advancement Devices

Purpose: The use of a mandibular advancement device (MAD) in the treatment of obstructive sleep apnea (OSA) is a consolidated therapy. This study aimed to evaluate the predictive value of awake upper airways (UA) functional endoscopy in identifying the outcome of MAD therapy. Methods: This observational prospective study included 30 adult OSA patients, all patients underwent pre-treatment awake UA functional endoscopy, during the exam subjects were instructed to advance their mandible maximally, and they were divided into three different groups according to the response of the soft tissue, group A (expansion), group B (stretch), group C (unchanged). The results of this test were used in combination with other noninvasive indexes to predict the treatment outcome in terms of apnea-hypopnea index (AHI) reduction. Results: We found that a substantial AHI reduction occurred in group A and group B while e slight AHI reduction was measured in group C. Conclusion: Based on our experience the awake UA endoscopy is a valid prognostic exam for discriminating responder and non-responder patients; in addition our results indicate the possibility of predicting a range of post-treatment AHI index values.

Digitally programmed (CAD) offset values for prototyped occlusal splints (CAM): assessment of appliance-fitting using surface-based superimposition and deviation analysis

AIM

Limited data are available on the fitting properties of prototyped occlusal appliances. The aim of the present study was to assess the fitting of prototyped splints digitally designed with different offset values and generated with two different biocompatible resins.

MATERIALS AND METHODS

Ten dental digital models were included, and occlusal splints were designed with different offset values (0.0, 0.05, 0.10, 0.15, 0.20, and 0.25 mm). Each splint was 3D printed using two different biocompatible resins, and the gap between the splint and the teeth was recorded by placing impression material. A specific 3D technology was used to assess the gap volume between the splint and the teeth and to calculate the Euclidean distance between the surface points of two digital models, with and without the gap volume.

RESULTS

The splints with a 0.20-mm offset value showed smaller gap volume and deviation analysis values compared with those with offset values of 0.15 and 0.25 mm (P < 0.05). These results were consistent with both types of biocompatible resins used. For each offset value tested, the gap volume and deviation value analysis did not significantly differ between the splints printed with the two different resins.

CONCLUSION

According to the present findings, the 0.20-mm offset value would be the best choice when digitally designing occlusal appliances.

Lingual treatment of an adult patient with an iatrogenic class II anterior open bite: Report of a case with a non-surgical orthodontic approach

INTRODUCTION

The treatment of adult patients presenting an open bite is a real challenge for orthodontists due to the complexity of the malocclusion. The diagnosis is essential to identify aetiological factors and establish the best aesthetic and functional therapeutic prognosis. Among the aetiological factors, iatrogenic treatment history has to be considered. It is the case here where a regrettable unsuitable splint for bruxism treatment forced an open bite to appear.

MATERIAL AND METHOD

This case report presents an adult women with a large open bite due to an occlusal splint not covering the last mandibular molars. It was not really a vertical skeletal excess but more a mandibular clockwise rotation linked to the molar extrusions, which created a dento-alveolar open bite and labio-mental contractions during lip closure. Treatment objectives were the intrusion of the third and second molars, the extrusion of incisors to obtain a counter clockwise mandibular rotation. The patient was treated with an aesthetic and customized lingual appliance with no orthognathic surgery. A physiotherapy was followed by the patient when the open bite was closed in order to facilitate and stabilize the intercuspation.

RESULTS

A complete closing of the open bite was reached after two years of treatment. The superimposition showed the anticlockwise mandibular rotation. The levelling with posterior intrusion and the incisors extrusion reduced the vertical dimension with success. After 3years of retention, the occlusal stability was obtained.

CONCLUSION

The intrusion of the molars associated with a counter clockwise mandibular rotation made it possible the incisor extrusion. The occlusal balance with physiotherapy and patient compliance maintained the closure. In this way, the iatrogenic effects of the poorly designed bite splint were repaired.

Mandibular advancement devices shorten desaturation duration in patients at high risk for obstructive sleep apnea syndrome during intravenous propofol sedation in the decubitus position

BACKGROUND

The purpose of this study was to determine the efficacy of a mandibular advancement device (MAD) for increasing patient safety during sedated total knee arthroplasty (TKA) and total hip replacement (THR).

METHODS

Forty patients undergoing TKA or THR surgery in the supine or lateral recumbent positions under spinal anesthesia were enrolled. Sedation and oxygenation were administered. The MAD (Sweet Sleep Anti-Snoring Device) was then placed after 15 minutes of observation. SpO2, PetCO2, blood pressure, and respiratory rate were recorded.

RESULTS

Sedated patients in the decubitus position had higher saturation nadirs, shorter desaturation durations, shorter airway obstruction durations, and fewer rescue events than those in the supine position. In patients at a high risk of obstructive sleep apnea syndrome (OSAS), desaturation duration, obstruction duration, apnea duration, desaturation duration, and rescue events were significantly lower after MAD placement. However, the saturation nadir did not improve after MAD placement.

CONCLUSION

The MAD may shorten the duration of desaturation events during spontaneous breathing sedative procedures in the lateral recumbent position but not in the supine position. Breathing patterns did not change from nasal breathing to oral breathing or vice versa between pre- and postplacement of the MAD. Sedation score evaluation affects breathing pattern changes from oral breathing to nasal breathing and vice versa.

The application of a new clear removable appliance with an occlusal splint in early anterior crossbite

BACKGROUND

The effectiveness of anterior crossbite treatment in preschool-aged children depends on the treatment design and patient compliance. Common early treatment appliances with steel wires and acrylic resin can bring about numerous problems, such as toothache, sore gums and mucous membrane injury. The aim of this study was to propose a new clear removable appliance to provide preschool-age children with an improved experience of early occlusal interference treatment.

METHODS

Appliances were designed with the help of 3-dimensional (3D) digital reconstruction oral models and fabricated using 3D printing technology and the pressed film method. Then, the mechanical properties of the original dental coping sheet and thermoformed aligners were assessed in a simulated intraoral environment. Preschool-age participants who displayed anterior crossbite were recruited in this study. Records (photographs and impressions) were taken before the treatment (T1), during the treatment (T2) and at the end of the treatment (T3). The effects of treatment were evaluated by clinical examination and questionnaires.

RESULTS

Normal degrees of overbite and overjet in the primary dentition were achieved using this new appliance. Dental and soft tissue relationships were improved. Questionnaires showed that the safety evaluation, degree of comfort and convenience grades of the appliance were all relatively high.

CONCLUSION

This explorative study demonstrates that our new clear removable appliance is able to correct early-stage anterior crossbite in a safe, comfortable, convenient and efficient way. Thus, it is a promising method to correct a certain type of malocclusion, and its clinical use should be promoted in the future.

Obstructive sleep apnea: A sharp increase in the prevalence of patients treated with nasal CPAP over the last decade in France

Introduction

Obstructive sleep apnea (OSA) is a frequent condition. In the absence of treatment, OSA is associated with a higher risk of traffic accidents and a large variety of diseases. The objectives of this study were to describe the characteristics of patients treated for OSA in France and assess the time trends in treatment.

Methods

The French National Health Data System is an individual database with data on all healthcare reimbursements for the entire French population. Based on this database, we included all patients aged 20 years or over who were treated with continuous positive airway pressure (CPAP) or mandibular advancement splint (MAS) between 2009 and 2018. Negative binomial models, adjusted for age, were used to assess time trends in treatment prevalence and incidence rates.

Results

In 2017, 2.3% of French adults aged ≥20 years were treated with CPAP (men: 3.3%; women: 1.3%). The highest prevalence was observed in people aged 70–74 years (5.0%). From 2009 to 2018, the annual prevalence of CPAP increased 3-fold and the annual incidence 1.9-fold. During the same period, the rate of patients reimbursed for MAS (first prescription or renewal) was multiplied by 7.6. The proportion of patients treated with CPAP in 2017 who were no longer treated in the subsequent year was 6.9%.

Discussion

The sharp increase in the incidence of OSA treatment probably reflects a better recognition of the disease in France. However, the prevalence of OSA treatment remains lower than expected based on the international literature. Further studies are needed to identify the obstacles to an optimal management of individuals with OSA in France.

Impact of mandibular advancement device therapy on cerebrovascular reactivity in patients with carotid atherosclerosis combined with OSAHS

PURPOSE

Obstructive sleep apnea-hypopnea syndrome (OSAHS) may affect cerebrovascular reactivity (CVR), representing cerebrovascular endothelial function, through complex cerebral functional changes. This study aimed to evaluate the change of CVR after 1-month and 6-month mandibular advancement device (MAD) treatment of patients with carotid atherosclerosis (CAS) combined with OSAHS.

METHODS

Patients with carotid atherosclerosis combined with OSAHS who voluntarily accepted Silensor-IL MAD therapy were prospectively enrolled. All patients underwent polysomnographic (PSG) examinations and CVR evaluation by breath-holding test using transcranial Doppler ultrasound at baseline (T0), 1 month (T1), and 6 months (T2) of MAD treatment.

RESULTS

Of 46 patients (mean age 54.4 ± 12.4 years, mean body mass index [BMI] 27.5 ± 4.5 kg/m²), 41 patients (responsive group) responded to the 1-month and 6-month treatment of MAD, an effective treatment rate of 89%. The remaining 5 patients (non-responsive group) were younger (47.4 ± 13.5 years) and had a higher BMI (35.8 ± 1.8 kg/m²). The responsive group had an improvement of apnea-hypopnea index (AHI) (events/h) from 33.0 ± 25.0 (T0) to 12.4 ± 10.4 (T1) and 8.7 ± 8.8 (T2), P < 0.001; minimum arterial oxygen saturation (minSpO₂) (%) increased from 79.8 ± 9.1 (T0) to 81.8 ± 9.4 (T1) and 85.2 ± 5.4 (T2), P < 0.01; longest apnea (LA) (s) decreased from 46.5 ± 23.1 (T0) to 33.3 ± 22.7 (T1) and 29.4 ± 18.5 (T2), P < 0.001; T90 (%) decreased from 10.3 ± 14.9 (T0) to 6.1 ± 11.8 (T1) and 3.3 ± 7.5 (T2), P < 0.05. Sleep architecture of these patients also improved significantly. The responsive group had a significant increase in left, right, and mean breath-holding index (BHI): left BHI(/s) from 0.52 ± 0.42 (T0) to 0.94 ± 0.56 (T1) and 1.04 ± 0.64 (T2), P < 0.01; right BHI(/s) from 0.60 ± 0.38 (T0) to 1.01 ± 0.58 (T1) and 1.11 ± 0.60 (T2), P < 0.01; mean BHI(/s) from 0.56 ± 0.38 (T0) to 0.97 ± 0.55 (T1) and 1.07 ± 0.59 (T2), P < 0.01), suggesting improved CVR.

CONCLUSION

Effective MAD therapy is beneficial for restoring cerebrovascular endothelial function in patients with CAS and OSAHS in a short period (1 month and 6 months).

TRIAL REGISTRATION

Clinical trial registration number: NCT03665818. September 11, 2018.

[Method and accuracy of determining the jaw position of repositioning splint with the aid of digital technique]

OBJECTIVE

To establish the workflow of determining the jaw position of repositioning splint with the aid of digital technique, and to evaluate the accuracy of this workflow and compare the accuracy of raising different vertical dimensions in vitro.

METHODS

A volunteer was recruited. The data of full-arch scans, cone beam computed tomography (CBCT) image and ultrasonic jaw motion tracking of the volunteer were acquired. The full-arch scans were merged with the CBCT image, which were then matched to the jaw motion tracking reference system. The jaw position of repositioning splint was determined when the anterior teeth opening was 3 mm and the condyle was in centric relation of the fossa in the sagittal plane. A digital repositioning splint was designed in the software based on virtual articulator and fabricated with additive manufacturing technique. After the splint was tried in, another CBCT image was taken and a qualitative analysis was conducted to compare the position of condyle between these two CBCT images. In the in vitro study, standard dental plaster casts with resin ball markers attached to the base were mounted onto a fully adjustable articulator in the intercuspal position. The dental casts were scanned by an extraoral scanner to establish digital models. The ultrasonic jaw motion tracking device was used to obtain simulated jaw movements on the articulator, which was repeated for three times. The digital models and data of jaw movements were merged in one coordination with the aid of bite forks. The jaw position of repositioning splint was determined by adjusting data of jaw movements, each of which was used to determine three vertical jaw positions 4 mm, 5 mm, and 6 mm with the horizontal jaw position of protrusion 2 mm. The virtual articulators with differently adjusted jaw movements were applied in designing repositioning splints, and the final repositioning splints and virtual jaw relationships were exported in STL format. Then the repositioning splints were fabricated with additive manufacturing technique and tried in plaster casts on the mechanical articulator, which were scanned and the jaw relationships on the mechanical articulator were exported later. The virtual jaw relationships and scanned jaw relationships were registered according to lower models and displacement of upper models was calculated. Ball markers were fit to acquire the coordinates of centers and absolute difference values of centers along three coordinating axes X, Y, and Z were calculated. One-way analysis of variance was conducted using SPSS 18.0 software to compare deviations of the three different vertical jaw relationships in two-side test and the significance level was 0.05.

RESULTS

With the aid of multi-source data fusion and individualized jaw motion, the clinical workflow of determining jaw position of repositioning splint was preliminarily established. The designed jaw position was realized on the right and the condyle was more inferior than the designed position on the left. Both displacement of the upper models and absolute difference values of centers showed no significant differences (P>0.05) in different vertical jaw dimensions. The displacement of the upper models was (0.25±0.04) mm. The absolute difference values of centers along the three coordinating axes X, Y, and Z were respectively (0.08±0.01) mm, (0.30±0.02) mm, and (0.21±0.04) mm.

CONCLUSION

A novel method of determining the jaw position of repositioning splint with the aid of digital technique is established. It is proved to be feasible by try-in after multi-data fusion, computer-aided design and computer-aided manufacturing. As is shown in vitro, it is accurate to apply this method in adjusting jaw position. Further clinical trial will be designed to evaluate its clinical effect.

[Method and accuracy of determining the jaw position of repositioning splint with the aid of digital technique]

OBJECTIVE

To establish the workflow of determining the jaw position of repositioning splint with the aid of digital technique, and to evaluate the accuracy of this workflow and compare the accuracy of raising different vertical dimensions in vitro.

METHODS

A volunteer was recruited. The data of full-arch scans, cone beam computed tomography (CBCT) image and ultrasonic jaw motion tracking of the volunteer were acquired. The full-arch scans were merged with the CBCT image, which were then matched to the jaw motion tracking reference system. The jaw position of repositioning splint was determined when the anterior teeth opening was 3 mm and the condyle was in centric relation of the fossa in the sagittal plane. A digital repositioning splint was designed in the software based on virtual articulator and fabricated with additive manufacturing technique. After the splint was tried in, another CBCT image was taken and a qualitative analysis was conducted to compare the position of condyle between these two CBCT images. In the in vitro study, standard dental plaster casts with resin ball markers attached to the base were mounted onto a fully adjustable articulator in the intercuspal position. The dental casts were scanned by an extraoral scanner to establish digital models. The ultrasonic jaw motion tracking device was used to obtain simulated jaw movements on the articulator, which was repeated for three times. The digital models and data of jaw movements were merged in one coordination with the aid of bite forks. The jaw position of repositioning splint was determined by adjusting data of jaw movements, each of which was used to determine three vertical jaw positions 4 mm, 5 mm, and 6 mm with the horizontal jaw position of protrusion 2 mm. The virtual articulators with differently adjusted jaw movements were applied in designing repositioning splints, and the final repositioning splints and virtual jaw relationships were exported in STL format. Then the repositioning splints were fabricated with additive manufacturing technique and tried in plaster casts on the mechanical articulator, which were scanned and the jaw relationships on the mechanical articulator were exported later. The virtual jaw relationships and scanned jaw relationships were registered according to lower models and displacement of upper models was calculated. Ball markers were fit to acquire the coordinates of centers and absolute difference values of centers along three coordinating axes X, Y, and Z were calculated. One-way analysis of variance was conducted using SPSS 18.0 software to compare deviations of the three different vertical jaw relationships in two-side test and the significance level was 0.05.

RESULTS

With the aid of multi-source data fusion and individualized jaw motion, the clinical workflow of determining jaw position of repositioning splint was preliminarily established. The designed jaw position was realized on the right and the condyle was more inferior than the designed position on the left. Both displacement of the upper models and absolute difference values of centers showed no significant differences (P>0.05) in different vertical jaw dimensions. The displacement of the upper models was (0.25±0.04) mm. The absolute difference values of centers along the three coordinating axes X, Y, and Z were respectively (0.08±0.01) mm, (0.30±0.02) mm, and (0.21±0.04) mm.

CONCLUSION

A novel method of determining the jaw position of repositioning splint with the aid of digital technique is established. It is proved to be feasible by try-in after multi-data fusion, computer-aided design and computer-aided manufacturing. As is shown in vitro, it is accurate to apply this method in adjusting jaw position. Further clinical trial will be designed to evaluate its clinical effect.

A Smart Mandibular Advancement Device for Intraoral Cardiorespiratory Monitoring

We propose a smart mandibular advancement device (MAD) that can monitor cardiorespiratory parameters intraorally. The device comprises a flexible hybrid wireless monitoring platform integrated with a MAD. This monitoring platform is based on acquiring the intraoral photoplethysmography (PPG) signals. It is designed on a double-sided flexible polyimide substrate. Our experimental measurements show that the PPG signals captured intraorally are highly correlated with the conventional PPG signals received from the fingertip. Intraoral PPG signals have vital information as well as adequate quality to be utilized for estimation of multiple-physiological parameters, such as heart-rate (HR), respiration rate (RR), respiration pattern (RP) and blood oxygen saturation (SpO₂). The estimated values of HR, RR, and SpO₂ from the intraoral PPG signals recorded by our smart MAD show an accuracy of over 96% with reference to the conventional monitoring techniques.

Comparison of immediate response to four conservative treatment modalities for management of masticatory myalgia with limited mandibular movement: a retrospective study

OBJECTIVE

Conservative treatment modalities are recommended for managing masticatory myalgia in individuals with temporomandibular disorders. The aim of this study was to retrospectively review and compare the effectiveness of four conservative treatments: counseling and occlusal splint therapy, counseling and manipulation integrated with electrophysiotherapy, the combination of the two treatments, and counseling only.

METHOD AND MATERIALS

One hundred and sixty-eight patients who had myalgia with limited jaw movement were retrospectively observed in this study. Between January 2015 and December 2017, 63 patients received counseling and stabilization occlusal splint therapy (Group 1), 35 patients received counseling and manipulation integrated with electrophysiotherapy (Group 2), 33 patients received the combination of counseling, splint therapy, and manipulation integrated with electrophysiotherapy (Group 3), and 37 patients received counseling only (Group 4). All subjects were followed up for 12 weeks. The intensity of spontaneous pain, palpation pain, chewing pain in the masticatory muscles, and range of pain-free maximal mouth opening were recorded in the clinical assessments. Intragroup and intergroup differences were examined by using analysis of variance (ANOVA) and the Kruskal-Wallis test.

RESULTS

Spontaneous pain in the masticatory muscles was relieved significantly in all groups at the 6-week visit (P < .05), and no significant difference was found among the groups (P > .05). Palpation pain was relieved significantly at the 9-week visit in the counseling + occlusal splint therapy group, counseling + manipulation + electrophysiotherapy group, and counseling + occlusal splint + manipulation + electrophysiotherapy group (P < .05). In the treatment group with counseling alone, significant palpation pain relief occurred at 12 weeks. Chewing pain was relieved significantly at the 6-week visit in the counseling + occlusal splint therapy group, counseling + manipulation + electrophysiotherapy group, and counseling + occlusal splint + manipulation + electrophysiotherapy group (P < .05), yet no significant difference compared to the baseline was observed in the counseling-only group (P > .05). A significant increase in the maximal range of pain-free mouth opening was observed at the 9-week visit in the counseling + occlusal splint therapy group, and at the 3-week visit in the counseling + manipulation + electrophysiotherapy group and counseling + occlusal splint + manipulation + electrophysiotherapy group (P < .05). Nevertheless, no significant change in the range of mouth opening was found throughout the follow-up period in the counseling-only group (P > .05).

CONCLUSION

Each of the included treatment modalities relieved spontaneous pain and tenderness to palpation of the masticatory muscles during the follow-up intervals. Counseling alone did not help patients with chewing pain and limited mouth opening in the short term. Treatment protocols including counseling, occlusal splint therapy, and manipulation, integrated with electrophysiotherapy showed the best short-term outcomes for symptomatic improvement.

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.