Is infrared thermography effective in the diagnosis of temporomandibular disorders? A systematic review

Thermographic findings related to facial pain - a survey of 40 subjects

OBJECTIVE

The purpose of this study was to assess how thermography findings relate painful symptoms and signs of temporomandibular disorders (TMD).

METHODS

Thermography, combined with chewing of paraffin wax, was performed on 40 subjects. The results were analyzed according to gender and pain-related TMD symptoms and clinical signs.

RESULTS

The overall temperatures after chewing were higher in TMD patients than in controls. For females, the most significant findings were the thermal increase between the relaxed state and subjects' state after chewing in temporal and temporomandibular joint (TMJ) regions. For males, all calculated parameters demonstrated a poor ability to discriminate TMD from controls.

CONCLUSION

Thermography could be a potential tool in diagnostics of female TMD patients. The results suggest that the thermal information assessed in specific facial areas could help to discriminate TMD patients from non-TMD patients and could be used to quantify the pain associated with TMD.

Acute outcomes of acupuncture and dry needling over peripheral acute fatigue in untrained healthy volunteers: A randomized controlled clinical trial

Peripheral acute fatigue (PAF) is defined as when the skeletal muscle is incapable of generating power. We aimed to investigate the acute effects of traditional Chinese acupuncture (TCA) and dry needling (DN) over PAF induced on the biceps brachii of untrained healthy volunteers. We conducted a randomized, single-blind controlled clinical trial. All volunteers (n = 45) underwent fatigue induction protocols repeated before and after treatment with TCA (TCA group; TCAg; n = 15), DN (DN group; DNg; n = 15), and rest (control group; Cg; n = 15). Assessments of PAF, skin temperature, and exercise time occur before and after each event: 1st fatigue induction (FI), treatment, and 2nd FI. We used repeated measures ANOVA adjusted with Bonferroni post hoc test to determine any change in tested variables (PAF-VAS, PAF-EMG, and skin temperature) at different time points compared to the baseline. Paired Samples t-test was used for the variable exercise times. All statistical tests considered' the significance level at p ≤ 0,05. There was no difference between groups in acute fatigue recovery (p = 0.19). All intragroup analyses were significant (p ≤ 0.05) and all volunteers show a reduction in fatigue perception after treatment (p ≤ 0,05), however, exercise time did not ameliorate after TCA or DN (p > 0.77). A single session of TCA and, DN can equally reduce fatigue, temperature, and exercise time over PAF induced on biceps brachii of untrained healthy volunteers.

Gingivectomy with high-power laser for correction of the gummy smile resulting from altered passive eruption-a case series

To compare the efficacy between the surgical techniques of gingivectomy with high-power laser (HPL) and conventional gingivectomy for correction of a gummy smile (GS) due to altered passive eruption (APE). This was a case series of six female patients diagnosed with GS associated with APE. For the conventional gingivectomy procedure and for the one using the diode laser (808 nm, 2 W, in continuous mode), the six upper anterior teeth were divided into two groups (control (CG)-# 11, # 12, # 13, and test (TG)-# 21, # 22, # 23). Analyses of intraoperative bleeding and levels of pain and postoperative tissue repair were performed. The thermal pattern analysis was performed using infrared thermography. The level of significance was set at p < 0.05. There was no intraoperative bleeding in the TGs (p = 0.002). The CG showed tissue repair significantly better than the TG on the 14th postoperative day (p = 0.004). There were no statistically significant differences regarding the level of postoperative pain between the groups (p > 0.05). Regarding the thermographic analysis, there were also no statistically significant differences (p > 0.05). HPL gingivectomy was more effective, regarding the absence of intraoperative bleeding, while the conventional technique promoted better tissue repair. No significant differences were observed in the other parameters, possibly due to the minimal damage caused by gingivectomy, with either HPL or the conventional procedure, as there was no removal of bone tissue.

Automatic Detection of Human Maxillofacial Tumors by Using Thermal Imaging: A Preliminary Study

Traditional computed tomography (CT) delivers a relatively high dose of radiation to the patient and cannot be used as a method for screening of pathologies. Instead, infrared thermography (IRT) might help in the detection of pathologies, but interpreting thermal imaging (TI) is difficult even for the expert. The main objective of this work is to present a new, automated IRT method capable to discern the absence or presence of tumor in the orofacial/maxillofacial region of patients. We evaluated the use of a special feature vector extracted from face and mouth cavity thermograms in classifying TIs against the absence/presence of tumor (n = 23 patients per group). Eight statistical features extracted from TI were used in a k-nearest neighbor (kNN) classifier. Classification accuracy of kNN was evaluated by CT, and by creating a vector with the true class labels for TIs. The presented algorithm, constructed from a training data set, gives good results of classification accuracy of kNN: sensitivity of 77.9%, specificity of 94.9%, and accuracy of 94.1%. The new algorithm exhibited almost the same accuracy in detecting the absence/presence of tumor as CT, and is a proof-of-principle that IRT could be useful as an additional reliable screening tool for detecting orofacial/maxillofacial tumors.

Artificial intelligence and infrared thermography as auxiliary tools in the diagnosis of temporomandibular disorder

OBJECTIVE

To assess three machine learning (ML) attribute extraction methods: radiomic, semantic and radiomic-semantic association on temporomandibular disorder (TMD) detection using infrared thermography (IT); and to determine which ML classifier, KNN, SVM and MLP, is the most efficient for this purpose.

METHODS AND MATERIALS

78 patients were selected by applying the Fonseca questionnaire and RDC/TMD to categorize control patients (37) and TMD patients (41). IT lateral projections of each patient were acquired. The masseter and temporal muscles were selected as regions of interest (ROI) for attribute extraction. Three methods of extracting attributes were assessed: radiomic, semantic and radiomic-semantic association. For radiomic attribute extraction, 20 texture attributes were assessed using co-occurrence matrix in a standardized angulation of 0°. The semantic features were the ROI mean temperature and pain intensity data. For radiomic-semantic association, a single dataset composed of 28 features was assessed. The classification algorithms assessed were KNN, SVM and MLP. Hopkins's statistic, Shapiro-Wilk, ANOVA and Tukey tests were used to assess data. The significance level was set at 5% (p < 0.05).

RESULTS

Training and testing accuracy values differed statistically for the radiomic-semantic association (p = 0.003). MLP differed from the other classifiers for the radiomic-semantic association (p = 0.004). Accuracy, precision and sensitivity values of semantic and radiomic-semantic association differed statistically from radiomic features (p = 0.008, p = 0.016 and p = 0.013).

CONCLUSION

Semantic and radiomic-semantic-associated ML feature extraction methods and MLP classifier should be chosen for TMD detection using IT images and pain scale data. IT associated with ML presents promising results for TMD detection.

Infrared Thermography in the Evaluation of Dental Socket Healing After Photobiomodulation Therapy: A Case Report

Introduction: The aim of this article was to evaluate the efficacy of photobiomodulation therapy (PBMT) in the alveolar tissue healing process post-extraction using infrared thermography (IT). Case Presentation: A 36-year-old male patient had teeth extractions (18 and 28). Four PBMT sessions (660 nm; 2 J per tooth) were performed in the region of tooth 28 and recorded with thermographic images to compare the healing process, bilaterally. In the first two postoperative sessions, the temperature was higher (hyperradiant) on the left side (treated). After the third laser application, the left side was hyporradiant. In later session, the treated side became hyperradiant compared to the control side. The alveolus of tooth 28 showed more rapid healing than tooth 18 over a period of 60 days. Conclusion: IT can be used to detect the favorable effect of PBMT on accelerating the healing process in the alveolus within 60 days after the tooth extraction.

Role of thermography in the assessment of temporomandibular disorders and other musculoskeletal conditions: A systematic review

The aim of this review was to evaluate whether thermal imaging may constitute a reliable assessment method of musculoskeletal and temporomandibular disorders (TMD/MSD). A systematic review was conducted in the Pubmed, Scopus, Cochrane library, Web of Science, and Lilacs databases. The search terms were "musculoskeletal disorders,""temporomandibular disorders,""infrared thermography,""thermography," and "infrared imaging." The inclusion criteria were: studies published between January 1985 and January 2021, performed in humans, with sample size equal or greater than 20 patients, written in English, Portuguese, French and/or Spanish, and full text available. The exclusion criteria were: systematic reviews, case studies, and/or studies focused on pathologies beyond the review's domain. The risk of bias was evaluated using CASP 2018. A total of 2032 articles were retrieved. Of these, 25 studies met the inclusion criteria and were included to withdraw the following information: title, type of study, first author and year of publication, objective, number of participants, comparisons, and principal conclusions. No RCT were found. Despite some disparity, points of convergence among the majority of authors could be found. In general, healthy individuals show subtle thermal differences between contralateral homolog areas. Concerning orofacial structures, unilateral symptomatic individuals may show thermal differences equal or greater than 0.4°C. Infrared thermography accuracy in diagnosing TMD/MSD is still considered low to moderate. Despite some limitations, IRT might constitute a valuable supporting diagnostic tool in the medical field of TMD and MSD.

Diagnosis of Temporomandibular Disorders Using Thermovision Imaging

Temporomandibular joint dysfunction (TMD) is a chronic disease of various etiologies. Correct TMD diagnosis enables to apply effective treatment and significantly improves the quality of patients' lives. One of the diagnostic methods subjected to evaluation in recent years is thermography, which enables safe, noninvasive, and quick imaging of the temperature distribution of temporomandibular joint-associated tissues. This paper, based on Medline, Dentistry & Oral Sciences Source, Academic Search Ultimate, Medline Complete databases, presents basic information related to thermovision imaging and outlines the direction of research conducted in recent years which fight with difficulties in the interpretation of thermograms that require specialized, dedicated analysis and processing of the obtained images. The problem concerns also no standardized protocol for measuring masticatory muscle temperature.

Adhesive dentistry sensory stimulus technique as a neuromechanism for the treatment of orofacial pain associated to temporomandibular disorders: Case study

Purpose

The authors intend, by presenting a case study, emphasize the neuromodulation process of orofacial pain induced by the stimulation of the sensory and motor stimulation of the trigeminal nerve, which can play an important role on pain modulation.

Materials and methods

A 25 year-old woman presenting orofacial pain was referred to the stomatology service at the Centro Hospitalar do Porto. After collecting the patient's anamnesis, the thermographic camera FLIR i7 was used to record the thermal status of the orofacial structures, before the adhesive dentistry sensory stimulus protocol, after 45 minutes, and after one week.

Results

This study suggests the relation of adhesive dentistry sensory stimulus technique in the neuromodulation of orofacial pain and its association with the temporomandibular disorders . As the tongue senses the stimulus of the resin composite placed on the palatal surface of the 1^st premolar, 2^nd premolar and 1^st molar of the maxilla, this can promote and induce an effect regarding a peripheral nerve neuromodulation resulting in a blockage of the nociceptive trigeminal pathway from temporomandibular disorders.

Conclusion

Orofacial pain is a common complaint among the patients that come to a dentistry appointment, which may have different diagnosis and treatments. A positive effect on the patient's symptomatology was confirmed clinically on subsequent dental appointments and monitored by infrared thermography.

Infrared thermography assessment of patients with temporomandibular disorders

OBJECTIVES

To assess patients with and without temporomandibular disorders (TMD) infrared thermography according to the differences in thermal radiance using quantitative sensitivity and specificity tests; and to evaluate the thermal asymmetry and the correlation of the thermal intensity with the intensity of pain upon palpation.

METHODS

This cross-sectional study performed a quantitative evaluation of clinical and thermographic examinations. The volunteers were evaluated for the presence of TMD using RDC/TMD (Diagnostic Research Criteria for Temporomandibular Disorders), and were divided into two groups: TMD group (n = 45); control group (n = 41), composed of volunteers without TMD, according to the Fonseca Anamnestic Index. The images were assessed for selected regions of interest for the masseter, anterior temporal and TMJ muscles. The mean values ​​of the areas of both groups were compared under the receiver operating characteristic curve. Spearman correlation analysis (non-parametric data) between pain level and mean temperature, by region, and the Pearson's χ² test was used to verify the association between the presence of temperature and pain asymmetry. The level of significance was set at p < 0.05.

RESULTS

Both Groups, with and without TMD, presented with absolute and non-dimensional mean temperature without statistical differences (p>0.05). When correlating temperature with intensity of pain upon palpation, a negative correlation was observed for the masseter muscle.

CONCLUSION

Infrared Thermography resulted in low area under the curve, making it difficult to differentiate TMD via thermographic analysis. The intensity of pain upon palpation in patients with TMD may be accompanied by a decrease in local temperature.