Pterygoid Muscle Research Articles

MRI evaluation of involvement of parotid and submandibular glands by tongue squamous cell carcinoma.

The majority of cases of salivary gland involvement are diagnosed in its late stages as may be missed in the evaluation, the low detection rate of involvement of salivary gland by OSCC may have significant impact on spread and recurrence of the OSCC. The study aimed to evaluate involvement of parotid and submandibular salivary glands by tongue oral squamous cell carcinoma. The 144 histo-pathologically proven cases of tongue squamous cell carcinoma were evaluated for clinical staging, margins and extent of tumor and involvement of salivary gland on T1-T2 Weighted, STIR, diffusion-weighted and contrast-enhanced MRI sequences and data was subjected to analysis. In tongue OSCC, total 9 (6.25%) patients showed salivary gland involvement, 2 of them involved parotid glands and 7 of them involved submandibular gland. The OSCC involving the salivary glands were in Stage 4 except for 2 cases with predilection for antero-lateral border and tendency towards midline crossing. Out of 9 cases that showed salivary gland involvement, the 5 cases showed direct involvement from the spreading lesion, the 3 cases showed the infiltration from adjacent lymph nodes and 2 cases showed infiltration from sublingual gland and medial pterygoid muscle. The present study revealed the greater percentage of OSCC with salivary gland involvement as compared to previous studies; in contradiction present study demonstrated higher involvement of submandibular gland compared to parotid gland with additional imaging features in salivary glands (15.97%) suggesting the likely possibility of their involvement by OSCC in near future.

Anatomy based corridors to the infratemporal fossa: Implications for endoscopic approaches.

BackgroundThe infratemporal fossa (ITF) represents an area densely packed with neurovascular structures within irregular boundaries. The goal of this study was to classify the ITF into zones corresponding to its anatomical spaces and the order in which they are encountered during an endonasal approach (anteroposterior axis).MethodsSix cadaveric specimens (12 sides) with injected colored latex were dissected. Following an endoscopic medial maxillectomy and Denker's approach, a progressive exploration of the masticator space and upper parapharyngeal space was completed. A classification of the ITF based on well‐defined spaces was ascertained.ResultsThe ITF was divided into five zones:Zone 1 (retromaxillary space)—space lying between the posterolateral wall of the maxillary sinus and the temporalis and pterygoid muscles.Zone 2 (superior interpterygoid space)—area including the superior head of the lateral pterygoid muscle, V3, and foramen ovale.Zone 3 (inferior interpterygoid space)—includes the inferior head of lateral pterygoid muscle, medial pterygoid, and temporalis muscles, and the space enclosed by these muscles.Zone 4 (temporo‐masseteric space)—space lateral to the temporalis muscle (comprising fat mostly).Zone 5 (tubopharyngeal space)—includes the Eustachian tube, tensor, and levator veli palatini muscles, and structures in upper parapharyngeal space. ConclusionThe ITF can be visualized as five zones based on spaces enclosed by the masticator muscles and upper parapharyngeal structures. This novel classification system is useful to guide endoscopic approaches to the ITF, while decreasing the potential for injury of neurovascular structures and pterygoid muscles.

A Comparative Study of Low-Level Laser Therapy and Transcutaneous Electrical Nerve Stimulation as an Adjunct to Pharmaceutical Therapy for Myofascial Pain Dysfunction Syndrome: A Randomized Clinical Trial

Objectives: Myofascial pain dysfunction syndrome (MPDS) is the most common form of temporomandibular disorders. Because of the multifactorial nature of the problem, its management usually involves several treatment modalities to maximize their synergistic effects. This randomized clinical trial aimed to assess the efficacy of low-level laser therapy (LLLT) and transcutaneous electrical nerve stimulation (TENS) as an adjunct to pharmaceutical therapy for treatment of MPDS.
 Materials and Methods: This clinical trial evaluated 108 MPDS patients. First, the initial pain intensity of patients was determined using a visual analogue scale (VAS). The first phase of the study included education, awareness, self-care, behavior and relaxation therapy. After 1 month, the pain score was measured again using VAS. Patients who acquired a pain score >1 were divided into three groups of LLLT with diode (GAAlAr) laser with 0.2 W power, TENS, and control, using block randomization. All groups received 10 mg fluoxetine once daily, 0.25 mg clonazepam once daily and 10 mg baclofen three times a day. ANOVA was used to compare the recovery rate of the three groups.
 Results: Pain in the trapezius muscle and pain on mouth opening resolved faster in the laser + medication group. The recovery rate was faster in the mean muscle pain, general pain reported by patients, pain in the masseter and pterygoid muscles and pain and limitation in lateral movements in both laser + medication and TENS groups.
 Conclusion: Combination of LLLT and TENS with medication accelerated pain relief and resolved movement restrictions in MPDS patients.
 (IRCT registration number: IRCT201411113144N4)

Evaluation of the effects of chronic qat chewing on lateral pterygoid muscle using MRI

ABSTRACT Objective: This study explored the effect of qat chewing (QC) on the lateral pterygoid muscle (LPM), using magnetic resonance imaging (MRI). Methods: Forty qat chewers (QG), divided into three subgroups, according to duration of QC, and 20 non-qat chewers (NQG) were included. MRI sections were obtained to assess hypertrophy and atrophy of the superior belly (SB) and inferior belly (IB) of the LPM on the chewing and contralateral non-chewing side. Results: There was a significantly higher prevalence of atrophy of the IB (p < 0.001) and hypertrophy of the SB and IB (p = 0.002) in the QG. Hypertrophy of SB and IB was marked (p = 0.001) on the chewing side. Conversely, SB atrophy was marked on the non-chewing side (p = 0.003). MRI demonstrated a positive correlation between LPM alterations and the duration of QC in subgroup analysis. Conclusion: Unilateral QC might be a cause of LPM alterations.

Possible Directions of Further Development of F.Ya. Dzerzhinsky’s Program in Research on the Jaw Apparatus of Birds

The works by F.Ya. Dzerzhinsky and his disciples have rendered the jaw apparatus of birds a conventional and thoroughly characterized research object for functional morphology in Russia. The author, who communicated with Dzerzhinsky for many years, attempts to reconsider his scientific heritage in a critical manner and to use it as a foundation for outlining the most promising directions of further research. The analysis shows that underestimation of the problem of muscle mass economy in the jaw apparatus, despite the critical importance of any excess ballast for birds, was a serious drawback of Dzerzhinsky’s method. A new model based on the separation of the kinematics of bill opening and food object compression provides a solution for the problem of economical use of muscle mass in the avian jaw apparatus. The length of the major jaw adductor muscles remains virtually unchanged when the bill is opened, so that these muscles act as inextensible links of the closed multilink kinematic chain of the kinetic skull. Length change upon mouth opening being unnecessary, these muscles can be short-fibered, that is, lightweight but strong. The large force of these muscles is only used by the bird when the object is fixed in the bill and the jaw joint locking mechanism is switched on; a different kinematic chain used for object compression only is formed in this case. If the nonparallel arrangement of the pterygoid muscle and the jugal bar is also taken into account, the avian capacity for using the full force potential of the jaw adductor muscles without careful adjustment to each food object and the specific conditions of food object capturing becomes easy to understand. The main elements of the proposed model, which were found out by Dzerzhinsky himself, acquire a new meaning in light of the concept of economical use of the muscle mass. This enables us to make a major generalization concerning the adaptive significance of the cranial kinesis in birds as a means of reducing the jaw adductors’ mass without decreasing their force. In addition to the new model of jaw mechanics, other promising directions are proposed for the development of Dzerzhinsky’s work based on the expansion of the set of methods. The analysis of the aponeurotic framework of jaw muscles from the standpoint of optimizing the spatial packaging of muscle fibers may be a promising topic for research based on a combination of computer tomography and computational modeling.

On the reinsertion of the lateral pterygoid tendon in total temporomandibular joint replacement surgery

This report aims to present the concept of reestablishing lateral pterygoid muscle function during total temporomandibular joint (TMJ) replacement surgery. The key feature is a lattice structure (scaffold) located in the condylar neck of a titanium, three-dimensionally (3D)−printed mandibular component that houses morselized autologous bone from the resected condyle and osteogenic stem cells from iliac bone marrow aspirate, and to which the fibrous enthesis component (collagen attachments to a bone fragment) is fixed via suture cerclage prior to the development of the bony union. Five TMJs were replaced using enthesis reconstruction in three patients who were followed for 1 year and more. Laterotrusion to the contralateral side measured on average 6.4 mm preoperatively, 2.3 mm at 1 month, 3 mm at 3 months, 4 mm at 6 months, and at 1–1.5 years (62,5% of the preoperative laterotrusion/40% of a normal laterotrusion). Subjective normalization of mastication after 1 year was present in all patients. A successful reattachment of the enthesis to an alloplastic endoprosthesis suggests that patients will not only be able to open and close their mouths properly with reduced pain but will also be able to actually chew. The technique has potential applications in orthopedic alloplastic reconstruction.

A three-dimensional analysis of masticatory muscles in laterognathism

ABSTRUCTPurposeBy using three-dimensional (3-D) CT imaging, the maxillofacial bones and muscles can be observed from any desired angles and analyzed the bone and muscles simultaneously. However, no studies have investigated the three dimensional analysis of muscles in jaw deformity. The purpose of this study was to examine the relationship between the morphology of the masticatory muscles and the craniofacial skeleton in the patients with facial asynmetry.MethodsEight Japanese normal female adults and 10 female adult patients with laterognqthism were participated in this study. The 3-D CT images of their craniofacial skeleton and masseter, medial pterygoid and lateral pterygoid muscles were recon-structed. Then, 6 skeletal and 7 muscle variables were measured for each subject.ResultsSignificant positive correlations were found among the volume of the masti-catory muscles in the normal adults, but not found in patients with mandibular laterognathism. The muscular variables showed significant positive correlations with skeletal variables in normal subjects, but few significant correlations were found in the patients with laterognathism.ConclusionsThis study suggestted that the balance between masticatory muscles and the balance between muscles and skeleton collapsed in the patients with mandibu-lar laterognathism.

Changes in the muscles of mastication before and after primary stereotactic radiosurgery in patients with idiopathic trigeminal neuralgia.

The motor root of the trigeminal nerve runs close to the sensory root and receives considerable radiation during Gamma Knife radiosurgery (GKRS) for trigeminal neuralgia (TN). The object of this study was to evaluate via MRI the changes in the muscles of mastication before and after upfront GKRS in patients with idiopathic TN. In this single-institution retrospective cohort study, all patients with idiopathic unilateral TN treated with primary GKRS at the University of Virginia in the period from 2007 to 2017 were included provided that they had pre- and post-GKRS MRI data. The thicknesses of the temporalis, pterygoid, and masseter muscles were measured on both pre- and post-GKRS MRI in a blinded fashion. Changes in the muscles like fatty infiltration, MRI signal, or atrophy were noted. Among the 68 patients eligible for inclusion in the study, 136 temporalis muscles, 136 medial pterygoid muscles, 136 lateral pterygoid muscles, and 136 masseter muscles were assessed. A subset of patients was found to have muscle atrophy even prior to GKRS. Pre-GKRS atrophy of the masseter, medial pterygoid, lateral pterygoid, and temporalis muscles was seen in 18 (26%), 16 (24%), 9 (13%), and 16 (24%) patients, respectively. Logistic regression analysis showed that distribution of pain in the V3 territory (p = 0.01, OR 5.43, 95% CI 1.46-20.12) and significant pain on chewing (p = 0.02, OR 5.32, 95% CI 1.25-22.48) were predictive of pre-GKRS atrophy. Reversal of atrophy of these muscles occurred after GKRS in a majority of the patients. The incidence of new-onset permanent post-GKRS muscle atrophy was 1.5%. The median follow-up was 39 months (range 6-108 months). A subset of patients with TN with significant pain on chewing have pre-GKRS disuse atrophy of the muscles of mastication. A reversal of the atrophy occurs in a majority of the patients following GKRS. New-onset motor neuropathy post-GKRS was rare.

Anatomical-based classification for transoral lateral oropharyngectomy

PurposeThe aim of the study is proposing a classification of different transoral lateral oropharyngectomy procedures in order to ensure better definitions of post-operative results. MethodsThe classification resulted from the consensus of the different authors and was based on anatomical-surgical principles. ResultsThe classification comprises three types of lateral oropharyngectomy: type 1 is the resection of the palatine tonsil deep to the pharyngobasilar fascia; type 2 is performed by removing the entire palatine tonsil, the palatoglossus muscle, the palatopharyngeal muscle and the superior constrictor muscle; type 3 is performed by removing the entire palatine tonsil, the palatoglossus muscle, the palatopharyngeal muscle, the superior constrictor muscle, the buccopharyngeal fascia with extension to the pterygoid muscle and parapharyngeal space fat content. Based on the extension of the dissection we can use the suffix A (soft palate), B (posterior pharyngeal wall), C (base of tongue) and D (retromolar trigone). ConclusionThe proposed classification introduces a simple and easy to use categorization of transoral lateral oropharyngectomies into three classes. Resection extensions are easily described using suffixes.

Soft Tissue Damage in Patients With Hemifacial Microsomia.

The aim of this study was to evaluate the extent of the damage to soft tissues on the affected side in patients with hemifacial microsomia (HFM). Nine patients with HFM were included in this study and underwent computed tomography (CT) examination in the craniofacial area. The axial and coronal CT images were used for evaluating the damage to related soft tissues. The results showed that the masseter muscle, temporal muscle, pterygoid muscles, and parotid gland were damaged on the affected side in all 9 patients with HFM. However, the extent of the damage to the pterygoid muscles was less than that to the masseter muscle, temporal muscle, and parotid gland. These findings indirectly support the crucial role of hemorrhage in the development of HFM, and the extent of damage to soft tissues may depend on the distance and barrier effect of the mandible between the hemorrhage and the affected tissues.

Endoscopic transorbital approach to the infratemporal fossa and parapharyngeal space: a cadaveric study.

The infratemporal fossa (ITF) and parapharyngeal space are anatomical regions that can be challenging to access without the use of complex, cosmetically disfiguring approaches. With advances in endoscopic techniques, a new group of surgical approaches to access the intracranial space through the orbit has been recently referred to as transorbital neuroendoscopic surgery (TONES). The objective of this study was to establish a transorbital endoscopic approach utilizing the inferior orbital fissure (IOF) to gain access to the ITF and parapharyngeal space and provide a detailed endoscopic anatomical description of this approach. Four cadaveric heads (8 sides) were dissected using a TONES approach through the IOF to reach the ITF and parapharyngeal space, providing stepwise dissection with detailed anatomical findings and a description of each step. An inferior eyelid approach was made with subperiosteal periorbital dissection to the IOF. The zygomatic and greater wing of the sphenoid were drilled, forming the boundaries of the IOF. The upper head of the lateral pterygoid muscle in the ITF and parapharyngeal space was removed, and 7 distinct planes were described, each with its own anatomical contents. The second part of the maxillary artery was mainly found in plane 1 between the temporalis laterally and the lateral pterygoid muscle in plane 2. The branches of the mandibular nerve (V3) and middle meningeal artery (MMA) were identified in plane 3. Plane 4 was formed by the fascia of the medial pterygoid muscle (MTM) and the tensor veli palatini muscle. The prestyloid segment, found in plane 5, was composed mainly of fat and lymph nodes. The parapharyngeal carotid artery in the poststyloid segment, found in plane 7, was identified after laterally dissecting the styloid diaphragm, found in plane 6. V3 and the origin of the levator and tensor veli palatini muscles serve as landmarks for identification of the parapharyngeal carotid artery. The transorbital endoscopic approach provides excellent access to the ITF and parapharyngeal space compared to previously described complex and morbid transfacial or transcranial approaches. Using the IOF is an important and useful landmark that permits a wide exposure.

Effect of Different Framework Materials in Implant-Supported Fixed Mandibular Prostheses: A Finite Element Analysis.

To evaluate the biomechanical behaviors of different framework materials in implant-supported fixed mandibular prostheses using three-dimensional (3D) finite element analysis. A model of a severely resorbed edentulous mandible was obtained from a tomography database. Morse taper-connection implants and multi-unit abutments were cut with an electro-erosion machine and scanned using a 3D scanner. The implants were positioned on the model at the bone level and distributed equally to support a fixed complete prosthesis. The simulations were divided into six groups according to the framework material: titanium (Ti); cobalt-chromium (Co-Cr); zirconia (ZrO2); polyether ether ketone (PEEK); carbon fiber-reinforced polyether ether ketone (CFR-PEEK); and polymethyl methacrylate (PMMA). The resultant load applied was obtained from the masseter, temporal, lateral, and medial pterygoid muscles. The principal stresses and von Mises equivalent stresses were analyzed and compared among the framework materials, and the results were described both quantitatively and qualitatively. PEEK and PMMA frameworks showed the highest total deformation values, showing decreases of von Mises stresses in the frameworks, implants, and abutments, but with a high tensile stress in the trabecular bone that achieved critical values. CFR-PEEK frameworks achieved their failure limit, whereas the ZrO2, Co-Cr, and Ti frameworks exhibited principal stresses in the bone region within physiologic limits. From a biomechanical point of view, the Ti, Co-Cr, and ZrO2 frameworks demonstrated the most favorable outcomes.

Association of volume and voxel intensity of the articular disc and lateral pterygoid muscle in migraine patients: a study with magnetic resonance imaging

Objectives: To compare the volume and voxel intensity of articular disc and lateral pterygoid muscle (LPM) between a group of migraine patients and a control group (those without history of headache) by using magnetic resonance imaging (MRI).Patients and methods: MRI scans of 17 migraine patients and 15 healthy controls subjects were analysed and processed, using ITK-SNAP software, by a single investigator, for calculation of volumes and voxel intensity of articular disc and superior and inferior head of LPM.Results: There were statistically significant differences between migraine patients and controls regarding the volume and voxel intensity of articular disc and inferior head of LPM, increasing in migraine patients. Intra-rater was highly consistent and reproducible (intra-class correlation coefficient [ICC] = 1).Conclusions: Higher voxel intensity in disc and inferior head of LPM of MRI scans was linked to the increased volume of articular disc, inferior head of LPM and migraine.

Injury responses of Sprague-Dawley rat jaw muscles to an experimental unilateral anterior crossbite prosthesis

ObjectiveDental occlusion are frequently changed in clinic. Molecular responses in jaw muscles to aberrant dental occlusion are changes are attractive, yet remain are obscure. DesignUnilateral anterior crossbite (UAC) prostheses were applied to Sprague-Dawley rats and then ceased after two weeks to detect the reactions of the masseter, a representative jaw elevator, and the lateral pterygoid muscle (LPM), a representative jaw depressor. ResultsTwo weeks of UAC elicited mild injury of the two muscles. Myogenesis and protective reactions were detected as increases in αB-crystallin expression in the masseter after 3 days and in the LPM after 2 weeks, and increases in desmin expression in both muscles after 2 weeks. A switch in fibre types from IIb to IIx occurred in the LPM but not in the masseter. Inflammatory responses, shown by the infiltration of inflammatory cells and increases in TNF-α mRNA expression, and fibrosis responses, shown by increased mRNA expression of Type I and III collagens, appeared very mild in the two muscles. These responses were partially recovered by the cessation of UAC. During the whole process, no obvious changes were observed in mitochondrial function, as indicated by the levels of proliferator-activated receptor γ coactivator 1α, mitofusin-2 and voltage-dependent anion channel. ConclusionsUAC causes injury and very limited inflammatory and fibrosis adaption in the masseter and LPM. Both muscles respond with myogenesis and protective activity. The LPM responds also with muscle fibre isoform alternations. These alterations were partially recovered by the cessation of dental stimulation at an early stage.

STUDY OF THE SIZE OF THE CORONOID PROCESS OF MANDIBULE

The mandible serves as an important structure in relation to mastication as all the muscles of mastication are attached to it. The Coronoid process is the anterior bony projected part of ramus of mandible giving attachment to two important muscles of mastication. The aim of our study was to observe the variation in the size of coronoid process in relation to its side (laterality), shape, age and sex. The material for this study comprised of 80 (160 sides) dry human mandibles. The age and sex differentiating criteria were detailed in materials and methods. The size of coronoid process was found to be approximately 1.5 mm longer on the right side than on the left side; 0.01 mm longer in males than females and 0.01 mm longer in dentulous than in edentulous. Triangular coronoid process was found to be the longest followed by round and then hook shaped. Male hormonal impact on muscle growth, bone remodeling and psychology probably lead to enhanced functional stress on mandible due to mastication as compared to that in females. Pterygoid muscles are involved mainly in side to side movement and Masseter-Temporalis (M-T) component in the robust vertical thrust during mastication for crushing. The condyloid process is for pterygoid and M-T-Coronoid Lever complex engenders the proportionate sexual dimorphism as observed in this study. Poor crushing activity in the edentulous is also corroborated in our observation.This comparative study is a pioneer study which will be beneficial for the Anthropologists, Forensic scientists and Reconstructive surgeons.

Extraoral Versus Intraoral Botulinum Toxin Type A Injection for Management of Temporomandibular Joint Disc Displacement With Reduction.

: The present study was conducted to compare between extraoral and intraoral approach for botulinum toxin type A (BTX-A) injection into the lateral pterygoid muscle (LPM) in patients suffering from anterior disc displacement with reduction (ADDWR).Fourteen patients suffering from ADDWR were included in this prospective cohort study. Patients were enrolled randomly into 2 groups according to injection approach; where extraoral used in group I, while intraoral approach used in group II. The LPM was injected with 20 IU BTX-A under electromyography (EMG) guidance. Postoperative evaluation of the patients included: mouth opening assessment, LPM tenderness, temporomandibular joint TMJ (clicking), and tenderness. The LPM insertional EMG activity was assessed. Also, magnetic resonance imaging (MRI) was performed to evaluate disc position. Descriptive and inferential analysis was conducted to compare between groups.There was significant patient's convenience during injection and significant injection time reduction in group II. A slight decrease in mouth opening immediate post-injection followed by significant improvement from 8th weeks post-injection was reported in both approaches. There was a significant improvement in TMJ clicking from 1st-week post-injection with no group difference. The EMG assessment documented LPM hyperactivity pre-injection followed by significantly decreased muscle activity at 8 and 16 weeks post-injection without statistical difference. The MRI showed no change in disc position after injection. CONCLUSION:: The BTX-A injection into LPM is a simple technique that can be used with high success and low complication rate for treatment of ADDWR. The intraoral approach was superior to the extraoral concerning patient convenience and injection duration with no statistical difference regarding other clinical outcomes.

Use of a Heister mouth gag as an aid to reduction in open treatment of condylar fracture.

The management of condylar fractures remains controversial. Open treatment of condylar fractures is a routine treatment in cases of displaced or dislocated condylar and subcondylar fractures. Because of the pull of the lateral pterygoid muscle, the condylar fragment is usually located anterior and medial to the mandible. Distraction of the mandible in an inferior direction simplifies proper reduction. Various distraction devices have been described in literature. We describe a technique of using the Heister mouth gag at the surgical site to aid in reduction of displaced dislocated condylar fractures.

A complex treatment of irreducible displacement of the temporomandibular joint disc and myofascial pain disorders with the use of botulinum toxin

Background. An irreducible displacement of the articular disc (IDD) is one of the TMJ conditions characterized by complexity of clinical manifestations, severity and is always accompanied by myofascial pain disorders.&#x0D; Objective. To improve the results of treatment of patients with TMJ IDD and myofascial pain syndromes.&#x0D; Methods. We performed a clinical examination and treatment of 38 patients with irreducible displacement of the TMJ articular disc and myofascial pain disorders. As additional research methods, we used CBCT, MRI, EMG. A step-by-step treatment was conducted, including a drug therapy, injection of botulinum toxin type A (BTA) in the masticatory, temporal, lateral pterygoid muscles (LPM) bilaterally; repositional splint therapy; arthrocentesis with the lavage of both articular spaces.&#x0D; Results. The overall effectiveness of the treatment was 97.4%. Out of 38 patients, 34 (89.5%) were treated without arthrocentesis with the complete restoration of the mandibular movement volume and elimination of pain syndrome.&#x0D; Conclusions. An effective system has been developed for a sequential complex treatment of TMJ IDD; a new technique has been developed for a periarticular injection access to the LPM allowing administration of a drug to its upper and lower heads. The high efficiency of BTA injections in the treatment of TMJ IDD is due to the mandatory drug administration into 3 muscles: masticatory, temporal and lateral pterygoid. In the treatment of TMJ IDD, arthrocentesis is effective with lavage of the lower and upper articular spaces.

Pilot study of trans-oral ultrasonography of temporomandibular joint in oblique sagittal plane

This pilot study aimed to investigate the feasibility of trans-oral ultrasonography of the temporomandibular joint (TMJ) in oblique sagittal plane. Six volunteers who were receiving residency training at Hainan Hospital of General Hospital of Chinese PLA were recruited into this study, five of them had normal TMJ and one had anterior displaced disc all of which had been confirmed by MRI. A hockey-stick-shaped ultrasound probe was placed between the cheek and maxilla to push against the mucosa lateral to posterior maxillary tuberosity, and every volunteer underwent bilateral scans. The sonographic imaging were completed successfully on the six volunteers; the condyle, the superior and the inferior head of the lateral pterygoid muscle, the disc and the maxillary vein were clearly identified in all the twelve ultrasonographic scans. The feasibility of trans-oral ultrasonography of TMJ in oblique sagittal plane was confirmed.

Intraoral photobiomodulation diminishes pain and improves functioning in women with temporomandibular disorder: a randomized, sham-controlled, double-blind clinical trial

The aim of the present study was to evaluate the effect of intraoral photobiomodulation involving super-pulsed laser (905nm) combined with red (640nm) and infrared (875nm) light-emitting diodes on pain, mandibular range of motion, and functioning in women with myogenous temporomandibular disorder. A randomized, sham-controlled, double-blind clinical trial was conducted involving 30 women with myogenous temporomandibular disorder diagnosed using the Research Diagnostic Criteria for Temporomandibular Disorders. The participants were randomly allocated to two groups (active and sham photobiomodulation). The evaluations involved this use of the visual analog scale, digital calipers, and a functional scale. Photobiomodulation was administered intraorally in the region of the pterygoid muscles, bilaterally, in all participants for a total of six sessions. Evaluations were performed on five occasions: prior to the intervention, immediately after the first session, 24h and 48h after the first session, and after the six sessions. Significant differences between groups were found regarding pain (p ≤ 0.01) and functioning (p ≤ 0.04). However, no statistically significant difference was found regarding range of mandibular motion. The findings demonstrate that intraoral photobiomodulation involving super-pulsed laser (905nm) combined with red (640nm) and infrared (875nm) light-emitting diodes diminishes pain and improves functioning but does not exert an influence on mandibular range of motion in women with temporomandibular disorder.Trial registration: NCT02839967.