Association between Anatomical Features of Petrotympanic Fissure and Tinnitus in Patients with Temporomandibular Joint Disorder Using CBCT Imaging: An Exploratory Study

A mechanoluminescent material, ZnS:Mn,Li, with enhanced brightness for visualizing dental occlusion

Mechanoluminescent materials are characterized by high luminescence intensity, high repeatability, no external voltage activation, and a good linear relationship between stress and mechanoluminescence intensity within a certain range. Therefore, mechanoluminescent materials have attracted increasing attention from researchers in the fields of stress sensing, encryption and anti-counterfeiting, structural health monitoring, energy-saving lighting, intelligent wearable devices, and other fields. In this study, ZnS:Mn powders with different Mn2+ ratios and different ion doping were synthesized by a high-temperature solid-phase reaction, and the synthesis of various materials was characterized. Then, the optimal mechanoluminescence effect of the ZnS:1%Mn,1%Li material was obtained. The photoluminescence intensity of ZnS:1%Mn,1%Li was 16.7 times higher than that of the sample without doping with Li+, and the mechanoluminescence intensity was 1.64 times higher. Finally, polyethylene terephthalate (PET) film was combined with ZnS:Mn,Li mechanoluminescent powders to prepare flexible three-layer composite film. Based on this, a feasible strategy for the detection of temporomandibular disorders was proposed. The composite film is easy to use, economical, and safe, and has good mechanoluminescent performance, which has potential application value in the field of occlusal force detection and visualization.

A global bibliometric analysis on the relationship between tinnitus and temporomandibular disorders

BACKGROUND AND OBJECTIVES

This global bibliometric review aimed to investigate trends in publications relating to tinnitus and TMD.

METHODS

A search was performed in eight databases (June/2022), by independent researchers with relevant keywords about tinnitus and TMD, without restriction of date or language. Original research or case report/series evaluating prevalence, association and risk related to tinnitus and TMD were included. Independent examiners selected studies by title and abstract and performed data extraction. Data about publication and researchers, study population, objective, study design and diagnostic criteria for tinnitus and TMD were exported to VintagePoint® for bibliometric analyses. Data about the direct association between tinnitus and TMD were extracted.

RESULTS

One hundred and seventeen articles from 25 countries were included, most observational (68.4%) and evaluating association (N = 60; 44.8%). Among the 60 studies of association, 22 (36.6%) presented results of a direct association between the presence/absence of tinnitus and the presence/absence of TMD. Brazil (19.5%) and the United States (12.7%) were the countries with the most publications, and Dentistry (48.6%) was the main publication area. A growth in publications in Dentistry was observed in the past 30 years and in the past 10 years in Medicine. Half of the studies included the elderly population (50.2%). The main diagnostic criterion for both tinnitus (37.8%) and TMD (28%) was general questionnaires and/or self-report.

CONCLUSION

There is a growing trend in publications relating to tinnitus and TMD, especially in Dentistry, with a predominance of observational and association studies in the elderly population using questionnaires and/or self-report. More research with robust diagnostic methods and other study designs should be encouraged in the future.

Evaluation of morphological variations of petrotympanic fissure using computed tomography imaging of the temporal bone

PURPOSE

Petrotympanic fissure (PF) is important for both dentists and otolaryngologists to know the temporal anatomy well especially for pre-surgical radiological evaluations. Computed tomography (CT) is indispensable method for temporal bone imaging. The purpose of this study was to evaluate PF morphology and position using CT.

METHODS

CT scans of 300 patients (600 PFs) were retrospectively evaluated. PF types were recorded by dividing into 3 groups (Type 1,2 and 3). Length of the mandibular fossa (MF) and PF, vertical diameter (VD) of the PF at the MF level, midpoint and tympanic cavity (TC) level were measured. PF position types were subdivided as low, midline and high.

RESULTS

Type 1, 2 and 3 was found in 18.7%, 51.5% and 29.8% of the cases, respectively. The mean length of the MF and PF was 18.33 mm and 3.77 mm, respectively. The mean VD of the PF at the MF level, midpoint and TC level was 1.71, 0.98 and 0.97 mm, respectively. The low, midline and high position of PF was observed 14.5%, 54.3% and 31.2% of the cases, respectively.

CONCLUSION

Length of the MF and PF in males was significantly higher than females. VD of the PF at the MF level in Type 1 and Type 3 was significantly higher than type 2. In type 1,VD of the PF at the midpoint was significantly higher than type 2 and type 3. VD of the PF at the TC level in Type 1 and Type 3 was significantly higher than type 2.

Petrotympanic Fissure Architecture and Malleus Location in Temporomandibular Joint Disorders

The aim of this research was to assess possible relationships between petrotympanic fissure (PTF) characteristics, malleus position, and temporomandibular joint disorders (TMD). A retrospective study was performed, including patients with TMD. Magnetic resonance imaging (MRI) and cone-beam computed tomography (CBCT) examination were used to evaluate temporomandibular joint (TMJ) disc position and condylar bone changes. Fifty-eight TMJs from twenty-nine patients (23:6 females: males) were assessed. Erosive changes (DDR-disc displacement with a reduction of 6 (24%), DDwR-disc displacement without a reduction of 8 (61.5%) vs. normal disc position 3 (15%), p = 0.012) and condyle osteophytes production (DDR 6 (24%), DDwR 9 (69.2%) vs. normal condyle 7 (35%), p = 0.012) were more frequent in subjects with disc displacement compared to normal disc position; malleus was closer to PTF in cases with erosive changes (median 2.15 interquartile range: (1.85–2.75) vs. 2.75 (2.25–3.15), p = 0.029) as well as those with condylar osteophytosis (2.25 (1.91–2.75) vs. 2.75 (2.33–3.32), p = 0.015); the PTF length was higher in cases with condylar osteophytosis compared to those without (4.45 (3.50–4.77) vs. 3.67 (3.34–4.28), p = 0.039). The disc position and disc shape were not related to PTF or malleus position. Malleus position and PTF dimensions were not associated with the PTF type. In cases with erosive changes and condylar osteophytosis, malleus was closer to PTF.

Evaluation of the relationship between temporomandibular joint disorders and tinnitus with computed tomography

PURPOSE

This study aimed to radiographically determine tinnitus and joint disorders by evaluating glenoid fossa depth and the horizontal angle of the ramus mandible in patients with isolated temporomandibular joint disorder and temporomandibular joint disorder with tinnitus by computed tomography (CT).

METHODS

In total, eighty two patients with temporomandibular disorders (TMDs) (forty two patients with tinnitus; forty patients without tinnitus) were evaluated using CT. CT images were analysed according to glenoid fossa depth and the horizontal angle of the ramus.

RESULTS

A total of 82 cases 43 (52.4%) female and 39 (47.6%) male were included. The distribution of gender was not significantly different between the TMD patients and the TMD-tinnitus patients (p >0.05). The mean age of the patients with isolated TMD was 31.70 ± 9.68 years, and the mean age of the patients with TMD-tinnitus was 34.07 ± 11.72 years. Comparisons were made of the right and left glenoid fossa depths of the patients with TMD and TMD-tinnitus, respectively. There was a statistically significant difference between the right glenoid fossa depths (p = 0.016) also there was also a statistically significant difference between the left glenoid fossa depths (p = 0.049).

CONCLUSION

Our study revealed that decreased glenoid fossa depth may be associated with an increased incidence of tinnitus in TMD patients by the way temporomandibular joint and ear can affect each other in diseases such as tinnitus due to their close anatomical relationship.

New Methods for the Acoustic-Signal Segmentation of the Temporomandibular Joint

(1) Background: The stethoscope is one of the main accessory tools in the diagnosis of temporomandibular joint disorders (TMD). However, the clinical auscultation of the masticatory system still lacks computer-aided support, which would decrease the time needed for each diagnosis. This can be achieved with digital signal processing and classification algorithms. The segmentation of acoustic signals is usually the first step in many sound processing methodologies. We postulate that it is possible to implement the automatic segmentation of the acoustic signals of the temporomandibular joint (TMJ), which can contribute to the development of advanced TMD classification algorithms. (2) Methods: In this paper, we compare two different methods for the segmentation of TMJ sounds which are used in diagnosis of the masticatory system. The first method is based solely on digital signal processing (DSP) and includes filtering and envelope calculation. The second method takes advantage of a deep learning approach established on a U-Net neural network, combined with long short-term memory (LSTM) architecture. (3) Results: Both developed methods were validated against our own TMJ sound database created from the signals recorded with an electronic stethoscope during a clinical diagnostic trail of TMJ. The Dice score of the DSP method was 0.86 and the sensitivity was 0.91; for the deep learning approach, Dice score was 0.85 and there was a sensitivity of 0.98. (4) Conclusions: The presented results indicate that with the use of signal processing and deep learning, it is possible to automatically segment the TMJ sounds into sections of diagnostic value. Such methods can provide representative data for the development of TMD classification algorithms.

Prevalence of New-Onset Otological Symptoms in Patients with Temporomandibular Disorders

The aim of this retrospective study was to evaluate the prevalence of new-onset otological symptoms and the possible associations between tinnitus and oral parafunctional habits among patients with temporomandibular disorders (TMD) who attended a Craniofacial Pain Outpatient and a Dentistry Clinic. The medical reports and charts of patients who experienced TMD between 1 February 2016 and 31 December 2017 were reviewed, in order to evaluate the prevalence of new-onset aural fullness, vertigo and tinnitus. Tinnitus was also analyzed in more detail to evaluate possible associations with parafunctional habits. A total of 400 patients (301 females, 99 males) met the inclusion criteria, with a median age of 39.6 ± 15.6 years. Overall, new-onset otological symptoms were reported by 304 (76%) subjects with TMD. Among otological symptoms, aural fullness was the most common (n = 133, 33.3%), followed by tinnitus (n = 92, 23%) and vertigo (n = 79, 19.8%). No significant correlations were found between tinnitus and bruxism (p = 0.28), clenching (p = 0.11), nail-biting (p = 0.96), sleeping prone (p = 0.27), chewing gum (p = 0.99) and talking for a long time (p = 0.42). The present study suggests that all patients with TMD should be investigated for new-onset otological symptoms, regardless of oral parafunctional habits. Early diagnosis would allow to plan personalized and appropriate therapeutic and rehabilitative pathways, minimizing the negative impact due to TMD.