Ultrasonographic evaluation of inflammatory changes in the masseter muscle

Ultrasonographic characteristics of myogenous temporomandibular disorders: A scoping review

OBJECTIVE

To identify the available evidence on the ultrasonographic characteristics of masticatory muscles in subjects with myogenous TMD, as well as the potential use of ultrasonography as a diagnostic and treatment assessment outcomes tool.

METHOD

An electronic search of the PubMed, Web of Science and Scopus databases was performed using the following terms: 'ultrasonography', 'ultrasound', 'masseter', 'temporal', 'masticatory muscles', 'temporomandibular disorders', 'temporomandibular joint disorders'. Full-text articles were obtained from the records after applying the inclusion/exclusion criteria.

RESULTS

Thirteen articles were included for analysis: one comparative cross-sectional study, five case-control studies, six clinical trials and one randomised clinical trial. Main ultrasonographic characteristic assessed were local cross-sectional dimension and intramuscular ultrasonographic appearance. Retrieved studies reported the use ultrasonography for diagnosis or treatment assessment purposes showing heterogeneous results. For diagnosis purposes, the results of local cross-sectional dimension are not consistent; therefore, its diagnostic value for myogenous TMD diagnosis is weak. However, more homogeneous results were observed for intramuscular ultrasonographic appearance showing a higher prevalence of type-II pattern in myogenous TMD subjects than non-TMD subjects. On the other hand, for treatment assessment purposes, muscles were observed thinner after treatment compared to pre-treatment. Also, results of intramuscular ultrasonographic appearance show disappearance or reduction of anechoic areas, higher prevalence of type-II pattern and significant distinction of echogenic bands were observed after treating TMD subjects.

CONCLUSION

Ultrasonography cannot be considered as a diagnostic instrument, but maybe as a complementary tool for treatment assessment of myogenous TMD subjects, even though future research is required to confirm its utility.

Evaluation of the efficacy of pharmacological treatment in patients with temporomandibular joint dysfunctions using ultrasonography

STATEMENT OF PROBLEM

Temporomandibular joint dysfunctions (TMDs) are complex problems affecting the temporomandibular joints (TMJs), masticatory muscles, or both. TMDs are considered muscle pain caused by contraction and ischemia in the masticatory muscles, but evaluation of the efficacy of pharmacological treatment is lacking.

PURPOSE

The purpose of this clinical study was to evaluate the changes in masticatory muscles, joint space, and main arteries supplying the TMJs after pharmacological therapy in patients with TMDs using ultrasonography (USG).

MATERIAL AND METHODS

The TMJ space, masseter and temporal muscles, temporal superficial artery (TSA), and facial artery (FA) were examined using USG in 30 participants with acute TMD pain before and after 10 days of symptomatic treatment with analgesic and myorelaxant. The bilateral masseter and temporal muscle thicknesses, joint space, and end-diastolic minimum velocity (Ved), minimum end-diastolic minimum velocity (Vmin), peak systolic maximum velocity (Vmax), pulsatility index (PI), and resistance index (RI) values of the TSA and FA were measured and compared before and after pharmacological treatment. The relationship between the masseter muscle thickness and the Ved and Vmin values of the TSA and FA before and after pharmacological treatment was analyzed using the paired sample t test; the relationship between the temporal muscle thickness, TMJ spaces, and Vmax, PI, and RI values of the TSA and FA was analyzed using the Wilcoxon signed-rank test (α=.05).

RESULTS

A significant difference was found between the right temporal muscle thickness before and after medication (P=.01), whereas no statistically significant difference was found in the left temporal muscle thickness (P>.05). A significant difference was found between pretreatment and posttreatment bilateral masseter thicknesses at rest (right P=.014; left P=.004). No statistically significant difference was found in the bilateral joint space or Vmax, Vmin, Ved, PI, and RI values of the TSA and FA before and after treatment (P>.05).

CONCLUSIONS

Pharmacological treatment in participants with acute TMD led to a reduction in masseter and temporal muscle thickness but did not significantly affect joint space and local blood flow. USG is a useful diagnostic tool in the diagnosis and follow-up of TMDs.

Identifying the course of the greater palatine artery using intraoral ultrasonography: cohort study

AIMS

The greater palatine artery (GPA) is one of the most important anatomical structure for free gingival grafts or connective-tissue grafts during soft tissue surgery for dental implants. Several studies have identified the approximate location of the GPA, but it is impossible to detect its exact location during surgery due to large variability between individuals. The authors, therefore, investigated the course of the GPA using intraoral ultrasonography to determine the feasibility of using real-time nonionizing ultrasonography for implant surgery.

MATERIALS AND METHODS

This study included 40 healthy young participants. The courses of the GPA were identified using intraoral ultrasound probes from the first premolar to the second molar. The distance from the gingival margin to the GPA (GM-GPA) and the depth of the palatal gingiva from the GPA (PG-GPA) were measured by two independent examiners. Measurements were analyzed statistically, and interexaminer reliability was determined.

RESULTS

The distance of the GM-GPA and the mean depth of the PG-GPA were 14.8 ± 1.6 mm and 4.10 ± 0.51 mm (mean ± SD), respectively. GM-GPA decreased when the GPA ran from the second molar to the first molar, and GM-GPA was significantly shorter in females (P < 0.05). PG-GPA increased when the GPA ran to the posterior teeth. Interexaminer measurement agreements were excellent, with intraclass correlation coefficient values of 0.983 and 0.918 for GM-GPA and PG-GPA, respectively.

CONCLUSIONS

Using an intraoral ultrasound probe, real-time GPA tracking is possible, which is expected to help reduce the possibility of bleeding during surgery.

Imaging of masseter muscle spasms by ultrasonography: a preliminary study

OBJECTIVES

The aim of this study was to determine the effectiveness of ultrasonography (USG) in locating spasm points in the masseter muscle.

METHODS

Fifteen patients with TMJ dysfunction and five healthy controls were included in the study. First clinical examination of TMJ and palpation of masticatory muscles were done. Then, the masseter muscles were examined by USG. A total of 40 masseter muscles were examined within the study.

RESULTS

Spasm points were observed as limited isoechogenic areas within normal heterogeneous muscle tissue. Within the 30 masseter muscles of patients with TMJ dysfunction, a total of 14 spasm points were detected clinically and 18 spasm points were detected ultrasonographically. No clinic or sonographic spasm point was detected in the masseter muscles of healthy controls.

CONCLUSION

USG demonstrated in detail the internal structure of the masseter muscle in all patients and provided precise localization of the spasm points on the muscle. This is a preliminary study, showing that changes in muscle internal structure can be visualized with USG.

Integration of ultrasound imaging into pre-clinical dental education

INTRODUCTION

Patients have complex healthcare needs and typically require more than one healthcare discipline to address issues regarding their health. Interprofessional teams of healthcare professionals may be able to address these complex needs and improve patient outcomes by combining resources. To evaluate the feasibility of integrating ultrasound into a dental school curriculum to teach anatomy as part of an interprofessional education experience, the current study surveyed first-year dental students to determine their perceptions of the integration of ultrasound techniques into the curriculum.

MATERIALS AND METHODS

Ultrasound laboratory exercises were developed for first-year dental students as part of their anatomy course. The exercises were focused on head, neck and abdominal anatomy. To assess student perception of the integration of ultrasound into the dental curriculum, a survey was created specifically for the current study.

RESULTS

Between 2013 and 2015, two classes of first-year dental students participated in the ultrasound laboratory exercise and completed the survey (n = 83). Student survey responses suggested ultrasound was a valuable teaching tool because it allowed them to visualise anatomical structures using live imaging. They also agreed that the ultrasound laboratory exercises were an efficient learning tool, but the majority did not believe that they would use ultrasound regularly in their future practice.

CONCLUSIONS

Results of the current study suggested first-year dental students were satisfied with the integration of ultrasound techniques into the dental curriculum. Survey results indicated that the students enjoyed the ultrasound laboratory exercise and felt ultrasound was an effective learning tool.

Magnetic resonance and sonographic imagings of masticatory muscle myalgia in temporomandibular disorder patients

This article reviews recently published studies investigating the MRI and sonographic diagnosis of masticatory muscle myalgia in temporomandibular disorder patients. The MRI and sonographic features of muscle after treatment are also discussed. Literature published within the last 15 years was obtained from the PubMed database using the following Mesh terms: magnetic resonance imaging (MRI) or sonography, masticatory muscle pain, and treatment. MRI and sonography enable accurate visualization and evaluation of the masticatory muscles, thereby increasing our understanding of pathology and cause of pain associated with these muscles. Although therapeutic efficacy is often evaluated based on clinical findings, MR and sonographic imaging studies may also be valuable.

Management of myofascial pain by therapeutic ultrasound and transcutaneous electrical nerve stimulation: A comparative study

OBJECTIVE

The present comparative study was aimed to determine the effectiveness of Th US and TENS in the management of myofascial pain in TMD patients.

MATERIALS AND METHODS

The present randomized comparative study was on 90 patients who were further assigned in three different groups each having 30 patients; Group I was healthy control patients, Group II was receiving Th US therapy, and Group III was receiving TENS therapy. All the 90 patients were further evaluated for maximum inter incisor subjective evaluation regarding muscle pain, impediment to daily life, massage impression on visual analog scale (VAS) scale, and intensity and duration used in Th US massage.

RESULTS

The masseter muscle thickness in control group was 12.00 (standard deviation [SD] ±1.1) mm when compared with TMD patient of 13.00 (SD ± 1.1) mm before treatment. Statistical significant findings on VAS score of muscle pain, impediment to daily life, and massage impression were observed in Th US. After treatment, the anechoic areas disappeared or were reduced in Th US group by 95.6% and in TENS by 74.4%.

CONCLUSION

Th US appeared to be subjectively better which was related to VAS score of massage impression, muscle pain, and impediment to daily life after treatment as well as sonographically related to existence of anechoic areas.

Role of ultrasonography in oral and maxillofacial surgery: a review of literature

Maxillofacial surgery, like any other surgical specialty is greatly dependent on the discipline of radiology. This poses a greater challenge because of the complex anatomy of this region. Various investigation modalities have been applied in diagnosing various diseases which are found in the maxillofacial region, including IOPA, PET, USG, CT, MRI and panoramic radiographs. Of these, USG can easily diagnose non invasive and soft tissue diseases. It is very useful in diagnosing the diseases which are not usually evident on a conventional radiograph. However; many of the dentists are not aware of the benefits of USG in diagnosis of oral diseases. In this article, the use of ultrasound in diagnosing the various pathologies of maxillofacial region is elaborated.

Recent advances of ultrasound imaging in dentistry--a review of the literature

Ultrasonography as an imaging modality in dentistry has been extensively explored in recent years due to several advantages that diagnostic ultrasound provides. It is a non-invasive, inexpensive, painless method and unlike X-ray, it does not cause harmful ionizing radiation. Ultrasound has a promising future as a diagnostic imaging tool in all specialties in dentistry, for both hard and soft tissue detection. The aim of this review is to provide the scientific community and clinicians with an overview of the most recent advances of ultrasound imaging in dentistry. The use of ultrasound is described and discussed in the fields of dental scanning, caries detection, dental fractures, soft tissue and periapical lesions, maxillofacial fractures, periodontal bony defects, gingival and muscle thickness, temporomandibular disorders, and implant dentistry.

Ultrasonographic evaluation of oral submucous fibrosis and masseteric hypertrophy

Objectives:

To evaluate the efficacy of ultrasonography (USG) as a non-invasive tool in assessing the severity of oral submucous fibrosis (OSMF) and also to assess the relationship between OSMF and hypertrophy of the masseter muscle.

Materials and Methods:

The submucosal thickness in buccal mucosa and masseteric muscle hypertrophy were measured using ultrasound (10-15 MHz) in 60 patients comprising 30 OSMF patients and 30 controls.

Results:

Results were analyzed by one way analysis of variance, Chi-square test and t-test. As the stages of OSMF advanced there was an increase in submucosal thickness of the buccal mucosa as well as masseter muscle thickness in both relaxed and contracted state in the study group when compared with controls (P < 0.005).

Conclusion:

USG is an effective non-invasive zero radiation tool for assessing the progression of OSMF.

The role of colour Doppler ultrasonography in the diagnosis of fascial space infections - a cross sectional study

AIMS AND OBJECTIVES

(1) To evaluate the role of ultrasonography with colour Doppler in the diagnosis of fascial space infections, (2) To determine the nature, size and extent of the odontogenic infections which involve the primary and secondary fascial spaces of the maxilla and the mandible (3) To evaluate the sensitivity of ultrasonography in determining whether the inflammatory process is in a stage of cellulitis or abscess and to thus determine the appropriate time for a surgical intervention during the course of the infection and to correlate the clinical and radiographic findings with the ultrasonographic findings and (4) to determine the treatment plan.

METHODOLOGY

Thirty four patients with odontogenic infections which involved the superficial and the deep fascial spaces of the head and neck were subjected to ultrasonographic examinations over the suspected area in the transverse and axial directions to determine the stage of the infection, its anatomic location and the treatment plan.

RESULTS

Ultrasonography showed 95.7% sensitivity and 100% specificity as compared to the clinical and radiographic diagnoses and it proved to be an effective investigation modality in the diagnosis of fascial space infections.

Evaluation of ultrasonography as a diagnostic tool in maxillofacial space infections

Objectives

The purpose of the study was to establish the role of ultrasonography in determining the involvement of specific fascial spaces in maxillofacial region and the stage of infection, in indicating the appropriate time for surgical intervention and to compare clinical and ultrasonographic findings.

Material and Methods

Twenty five patients with fascial space infection in maxillofacial region were subjected to ultrasonographic examination following a detailed clinical and radiological examination. Ultrasonography guided needle aspiration was performed. Based on the findings, patients diagnosed with abscess were subjected to incision and drainage and those with cellulitis were subjected to medical line of treatment.

Results

More than one fascial space was involved in all patients. On clinical examination 64 spaces were involved, of them 34 spaces had abscess formation and 30 spaces were in the stage of cellulitis. On ultrasonography examination, 28 spaces were reported to have abscess formation and 36 spaces were diagnosed to be in the stage of cellulitis. On comparative analysis of both clinical and ultrasonographic findings, ultrasonography was found to be sensitive in 65% of the cases and having specificity of 80%. It was registered statistically significant (P < 0.001) agreement between these two methods of assessment (kappa index = 0.814).

Conclusions

Ultrasonography is a quick, widely available, relatively inexpensive, and painless procedure and can be repeated as often as necessary without risk to the patient. Thus ultrasonography is a valuable diagnostic aid to the oral and maxillofacial surgeon for early and accurate diagnosis of fascial space infection, their appropriate treatment and to limit their further spread.

Masseter muscle sonographic features as indices for evaluating efficacy of massage treatment

OBJECTIVE

The aim of this study was to clarify the sonographic features of the masseter muscle as indices for judging the efficacy of massage treatment.

STUDY DESIGN

Fifteen patients with temporomandibular disorder (10 with unilateral and 5 with bilateral muscle pain) underwent massage treatment alternately on the bilateral masseter and temporal muscles with an oral rehabilitation robot. Sonography was performed before and after treatment, and the masseter thickness and existence of anechoic areas were evaluated.

RESULTS

The thickness on the symptomatic side in the unilateral group significantly decreased after treatment. Anechoic areas were shown in 20 muscles (66.7%) before treatment, and disappeared or were reduced in size in 17 muscles (85.0%) after treatment. The pretreatment thickness was significantly related to visual analog scale (VAS) scores regarding posttreatment muscle pain and massage impression. The existence of anechoic areas was relevant to VAS scores regarding muscle pain.

CONCLUSION

Masseter thickness and existence of anechoic areas might be related to the therapeutic efficacy regarding muscle pain.

The use of ultrasound in the investigation of the muscles of mastication

The aim of this article was to review the literature concerning ultrasonography imaging (US) of the muscles of mastication and to discuss its use, advantages and disadvantages and the findings of the authors. A web search was performed using the terms "ultrasound" and "muscles". US has been shown to be a reliable method of great utility in the field of diagnosis of alterations in the muscles of mastication and for the study of changes during growth and aging. It should be preferred in comparison to computerized axial tomography (CT) and magnetic resonance imaging (MRI) because of its safety and cost advantages since it is as reliable and precise as these other techniques. Although various techniques have been used in ultrasonographic scanning, this article discusses those techniques most commonly adopted by the authors.

Ultrasound-guided drainage of submasseteric space abscesses

PURPOSE

The oral approach for incision and drainage (I and D) in patients presenting with submasseteric space (SMS) abscesses and marked trismus is more difficult and requires a general anesthetic, necessitating an anesthetist experienced in fiberoptic-guided nasal intubation. In such patients, ultrasound-guided drainage (USGD) has been attempted to obviate this need. The purpose of this trial was to report our experience with the surgical management of 11 SMS abscesses, with special reference to their USGD.

MATERIALS AND METHODS

Seven men and 4 women ranging in age from 18 to 41 years (average age, 25 years) participated in this trial. They were initially examined with US, and their abscesses were subsequently drained under US guidance using a 16-gauge intravenous catheter. An antibiotic regimen was prescribed, and arrangements were made to see the patients daily for 5 days. USGD was repeated after 24 hours, and 24 hours later the infection course was monitored in each patient. Patients with nonresolving infection had their abscesses formally incised and drained extraorally. The source of infection was removed as soon as the acute phase of infection passed and the interincisal opening (IIO) allowed. The catheter or corrugated drain was removed when the discharge ceased or became minimal. Patients were then instructed to continue a 3-day course of an antibiotic and to return after 1 week and then after 1 month.

RESULTS

Resolution of infection was successfully achieved by USGD with no need for I and D in 8 of the 11 patients (73%). In those patients, the average total amount of pus removed was 8.5 mL, and the average IIO was 17.4 mm immediately after an average initial aspirate of 4.5 mL of pus. I and D was required in the remaining 3 patients (27%). In those patients the average total amount of pus removed was 17.5 mL, and the average IIO was 7.7 mm immediately after an average initial aspirate of 9.3 mL of pus.

CONCLUSIONS

Resolution of infection with USGD is more probable if there was an immediate improvement of the IIO to about 1.5 cm or more after an initial aspiration of 5 mL of pus.

Ultrasonographic features of the masseter muscle in female patients with temporomandibular disorder associated with myofascial pain

OBJECTIVE

The purpose of the present study was to examine ultrasonographic appearances in female patients with temporomandibular disorder (TMD) associated with myofascial pain in comparison with healthy volunteers.

STUDY DESIGN

The thickness of the masseter muscle in 25 female patients with TMD was measured at rest and at maximum contraction using ultrasonography. The visibility and width of the internal echogenic bands of the masseter muscle were also assessed and the muscle appearance was classified as 1 of 3 types: type I, characterized by the clear visibility of the fine bands; type II, thickening and weakened echo-intensity of the bands; type III, disappearance or reduction in number of the bands.

RESULTS

There were significant differences in the thickness at rest and the increase ratio by contraction between the patient and control groups. The distribution of muscle types showed a significant difference between the 2 groups.

CONCLUSION

The ultrasonographic features of the masseter muscle in TMD patients with myofascial pain were clarified and they might be related to muscle edema.

Color Doppler sonography of the facial artery in the anterior face

OBJECTIVES

The purpose of this study was to clarify the Doppler sonographic features of the facial artery in the anterior face in healthy volunteers and to investigate those of related hemangiomas.

STUDY DESIGN

Forty-six volunteers and 3 patients with hemangiomas were examined with Doppler sonography. The detection rates of the facial artery in the anterior face were determined. The features of the main trunk, superior and inferior labial branches, and the branches in the buccinator area were investigated together with the flow diameter, flow velocities, and resistive and pulsatility indexes.

RESULTS

The detection rates of the main trunk and superior and inferior branches were 100%, whereas that of the branches in the buccinator area was 92.4%. There were no significant differences in the measured values for all indexes between the right and left sides. However, there were significant correlations between right and left sides in the flow diameter and minimum velocity of the main trunk and in the flow diameter and pulsatility index of the superior labial branch. The Doppler sonographic features of the hemangioma were characterized as a hypoechoic area with internal and surrounding blood flows.

CONCLUSIONS

Doppler sonography can clearly depict the facial artery and its branches in the anterior face, and this method appears to be useful in the follow-up examination of hemangiomas in this area.

Colour Doppler sonographic analysis of blood-flow velocity in the human facial artery and changes in masseter muscle thickness during low-level static contraction

Muscle oedema, which can be seen as a thickness increment by ultrasonography, is important in provoking pain and fatigue during low-level contraction. Although oedema is related to the balance of inflow and outflow of blood, there are no data on the correlation between muscle thickness change and blood-flow. Blood-flow velocities in the facial artery and the muscle thickness changes were measured by colour Doppler ultrasonography in 30 healthy volunteers during 20 min contraction with 10% of maximum force. Thickness and velocity changes both reached a peak in the initial phase of contraction. The initial change of thickness did not correlate with the velocity in the facial artery, while those immediately after exercise showed a high correlation. The velocity changes in the facial artery might depend on both the general response to contraction and local metabolic or mechanical factors in the contracted masseters.

Blood flow in and around the masseter muscle: normal and pathologic features demonstrated by color Doppler sonography

OBJECTIVE

The purpose of this study was to clarify the normal findings of arteries in and around the masseter muscle and to present their pathologic changes with the use of color Doppler sonography.

STUDY DESIGN

The vascular appearances were examined for the 4 main arteries feeding the masseter muscle in healthy volunteers (n = 38) and patients with inflammation (n = 5) and intramuscular hemangioma (n = 3). The features of these arteries were investigated together with the flow diameter, flow velocities, and arterial resistances. The symmetry indices were also calculated to assess the pathologic changes.

RESULTS

The detection rates of the branch from the transverse facial artery, the masseter artery, and the branch from the maxillary or external carotid artery were 98.7%, 21.1%, and 84.2% in healthy volunteers, respectively. The facial artery that feeds the muscle from the inferior part represented 2 patterns according to anatomic variant: the masseteric branch (22.4%) and the main trunk itself (77.6%). The means of the flow diameter, maximum and minimum velocities, resistive index, and pulsatility index in healthy subjects were 1.8 mm, 24.6 cm/s, 5.1 cm/s, 0.80, and 2.51, respectively. In most of the patients with symptoms, the symmetry indices of all measurement values increased in comparison with those of healthy volunteers.

CONCLUSION

Color Doppler sonography is useful in describing the arteries in and around the masseter muscle and has the potential of being used to depict the pathologic changes.

Submasseteric abscess: report of two cases

Submasseteric abscess is a rare infection with the symptoms of cheek tenderness and marked trismus. Submasseteric abscess is located between the masseter muscle and mandibular ramus with different appearances as sepsis, infection, or tumor. Two cases of submasseteric abscess are reported along with symptoms, causes, and management techniques. Adequate drainage and antibiotic infusion are the treatment of choice. The differential diagnosis of cheek swelling and tenderness that should be considered are parotitis, parotid gland tumor, temporomasseter joint arthritis, and submasseteric abscess.

Ultrasound-guided needle aspiration of lateral masticator space abscess

Shortly after admission with facial space infection, ultrasound-guided needle aspiration of lateral masticator space abscess was carried out in 2 adult patients. One abscess was associated with pericoronitis and the other with post-extraction infection. Successful aspiration of pus was followed by an instantaneous improvement in the ability to open the mouth for a period of at least 24 hours. This obviated the need for conscious nasoendoscopic intubation and allowed orotracheal intubation for conventional drainage. We concluded that ultrasonography can be beneficial in the management of orofacial infections.

Ultrasonography evaluation of bone lesions of the jaw

The ultrasonographic aspects of 72 intraosseous lesions of the jaws were evaluated to identify the usefulness of this type of examination. The principal aim of ultrasonography was to recognize the lesion's content before surgical treatment. Four groups of lesions were classified after the definitive histopathologic examination: lesions with solid, liquid, dense liquid, and mixed contents. The initial ultrasonography examination was in agreement with the histopathologic findings in 24 (92.3%) cases with solid content, 17 (73.9%) cases with liquid content, 7 (7.7%) cases with dense liquid content, and 13 (92.8%) cases with mixed content. On the basis of the results of this study, we propose the use of ultrasonography as a complementary examination for intraosseous lesions of the jaws. If a liquid component is identified in ultrasonography, a surgical procedure should be performed immediately. Otherwise, if a lesion with solid component is identified, it should be biopsied for histopathologic examination and final diagnosis before definitive surgery.