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

Ultrasonographic evaluation of the effect of splint therapy on masseter muscle and blood flow in patients with bruxism

OBJECTIVE

To investigate the effect of splint therapy on masseter muscle and blood flow in patients with bruxism using ultrasonography (USG).

METHODS

Twenty female patients with bruxism receiving splint treatment were studied. Masseter thickness and elasticity were assessed using gray-scale USG and shear-wave elastography (kPa) at rest and maximum clenching. Blood flow parameters of external carotid artery (ECA), maxillary, facial, mental artery were examined using Doppler USG before and after splint application.

RESULTS

Thickness and elasticity of masseter muscle was statistically significantly decreased at rest after splint therapy (p < 0.05). Significant difference was determined only in some parameters of ECA and maxillary artery in Doppler USG before and after splint (p < 0.05); there was no difference for facial and mental artery (p > 0.05).

CONCLUSION

Thickness and elasticity of masseter muscle were significantly decreased after splint therapy. USG can measure muscle activity and blood flow in bruxism patients.

Lateral branches of the facial artery and its clinical implications

The facial artery is the main artery supplying blood to the face and is known to have facial branches of the inferior labial, superior labial, lateral nasal and angular arteries. These known major branches of facial artery run medially, however, there are sometimes branches of the facial artery heading laterally. The purpose of the present study was to investigate the lateral branches of the facial artery in face. We dissected facial branches of the facial artery in 74 cadaveric hemifaces. We investigated the presence of the lateral branches of the facial artery. Following parameters were investigated: lateral branch presence, the location of its origin, and the lateral branch diameter. Among the lateral branches, we evaluated the prevalence and diameter of the premasseteric branch. Lateral branches were observed in 48 of the 74 hemifaces (64.9%). The total number was 81 in the 48 hemifaces. The most common origin was between the inferior border of the mandible and inferior labial artery origin (42 of 81, 51.9%). The mean diameter of all lateral branches of the facial artery was 0.7 mm. Among the lateral branches, the premasseteric branches were present in 38 of 74 specimen (51.4%) and the mean diameter was 0.8 mm. The lateral branches of the facial artery may be registered in Terminologia Anatomica based on their prevalence. Accurate knowledge of the anatomy of the lateral branches of the facial artery is helpful for clinicians to avoid complications during facial procedures or maxillofacial surgeries.

The Premasseteric Branch of the Facial Artery: A Review and Translation of Adachi's Work

The premasseteric branch of the facial artery is a variable posterior branch that is closely associated with the anterior border of the masseter muscle. Since its first description, the premasseteric branch has been described using different terms such as the masseteric or posterior branch of the facial artery. While the artery’s anatomy is known, it is infrequently discussed in the literature. This manuscript reviews the artery’s origin, course, and importance during maxillofacial procedures, especially those involving manipulation of the masseter. We also provide a translation of Adachi’s 1928 German text describing the branch.

Ultrasound Assessment of Muscle Injury Associated with Closed Limb Fracture

Objective

The aim of this study was to assess muscle injury associated with upper and lower closed limb fracture using ultrasound, and to develop ultrasound classification criteria for muscle injury.

Patients and Methods

Thirty patients with limb fracture and muscle injury participated in this study. Ultrasonography was used to assess muscle fibre, hematoma, vascular injury, and diameter growth rate. Injury was classified into three grades according to the ultrasound imaging: scores of less than, equal to, or greater than 9.

Results

Of 30 patients, focal fibre rupture was observed in 11 cases; in 9 cases, the injured area exceeded 30% of the muscle area. Six patients had muscle hematoma (the largest reaching 39 mm); in 4 patients, the hematoma showed a honeycombed pattern. Vascular rupture was observed in 6 patients, of which 2 had decreased main arterial diameter and blood flow. The greatest increase in muscle thickness was 17 mm. Of all patients, 11 showed an increase in the diameter growth rate of the muscle exceeding 50%. In addition, among the 30 patients, 11 patients with scores ranging from 4 to 8 received conservative treatment; 9 patients with scores ranging from 10 to 14 received operative treatment; and 10 patients with scores equal to 9 received either conservative or operative treatment.

Conclusions

Ultrasonography is useful for diagnosing muscle injury associated with closed limb fracture. The ultrasound classification criteria for muscle injury can be used to assess the severity of injury and guide the decision of treatment.

A cadaveric study on variations in branching pattern of external carotid artery

Variations in the vascular anatomy of the carotid triangle have been reported in current scientific literature. The carotid arteries, being the major feeding arteries of the head and neck deserve special importance and protection from iatrogenic injury during radiological evaluations and surgical interventions. The present study was carried out over a period of 4 years from 2012–2016 to assess the variant anatomy of external carotid artery. The external carotid artery and its branches were dissected bilaterally in 40 formalin embalmed cadavers. The external carotid artery was traced from its origin to termination and variations in the branching pattern as well as the level of the carotid bifurcation were observed and analysed. A higher carotid bifurcation was observed in 25% cases. The linguofacial trunk was the commonest variation noted in the branching pattern seen in 20% cases. A single case of unilateral thyrolinguofacial trunk was also observed. The external carotid artery gave rise to accessory branches in 7.5% cases namely the superior laryngeal, accessory ascending pharyngeal and masseteric branches. A slender branch to the internal jugular vein was also observed in one case. These findings may provide further insight into the understanding of the vascular anatomy of the carotid triangle to the curious student, the discerning radiologist and the vigilant surgeon to avert complications and help improve overall treatment outcome.

Ultrasonographic evaluation of masseter muscle thickness in patients with disk displacement with reduction

OBJECTIVES

This study was performed to ultrasonographically assess the masseter muscle thicknesses of individuals with disk displacement with reduction.

METHODS

The thickness of the masseter muscle in 100 patients (28 male, 72 female; average age 34 years) who presented with one-sided temporomandibular joint pain and a clicking sound and were diagnosed with disk displacement with reduction was measured in relaxation and at maximum contraction using ultrasonography.

RESULTS

In the contracted position, the difference in the masseter muscle thickness between the healthy side and the side with disk displacement with reduction was statistically significant (p < 0.05). However, no statistically significant difference was found between the two sides in the relaxed position.

CONCLUSIONS

Obvious ultrasonographic changes of the masseter muscle were found in patients with temporomandibular disk displacement with reduction, and these changes might be related to unilateral chewing. Individuals with anterior disc displacement probably chew unilaterally because of pain and clicking.

Use of platelet-rich plasma to facilitate wound healing

Platelet-rich plasma (PRP) is widely used nowadays in different fields of medicine, affecting physiological processes including tissue regeneration. The use of PRP in maxillofacial surgical interventions and its efficiency in the improvement of postoperative wound healing were analysed. Patients undergoing plastic and reconstructive surgeries in the maxillofacial region were recruited: 50 patients were enrolled into a control group (received no PPRP injection) and 50 patients were enrolled into a treatment group, where PRP was applied during the surgical procedure. Evaluation of treatment outcomes was carried out by determination of IL-1β, TNFα, and IL-6 cytokines levels in the wound-drain fluid. The stages of wound healing were assessed by cytological analyses and ultrasound within a month period. The use of the PRP has substantially positive effects, contributing to the improvement of the healing process. In the treatment group, fibroblasts, macrophages, and collagen fibres appeared and their quantities increased earlier than when compared with control group patients. The concentration of IL-1β and TNFα in wound fluid on day 1 and day 5 after operation was higher for the treatment group as opposed to the control group, which was linked to the influence of PRP on inflammatory and granulation phases of the healing process. An ultrasound examination showed less oedema and infiltration in the tissues around the wound of the treatment group.

The relationship between masseter muscle thickness measured by ultrasonography and facial profile in young Korean adults

Purpose

The purpose of this study was to evaluate the relationship between masseter muscle thickness, facial morphology, and mandibular morphology in Korean adults using ultrasonography.

Materials and Methods

Ultrasonography was used to measure the masseter muscle thickness bilaterally of 40 adults (20 males, 20 females) and was performed in the relaxed and contracted states. Facial photos and panoramic radiography were used for morphological analyses and evaluated for correlations with masseter muscle thickness. We also evaluated the correlations of age, body weight, stature, and body constitution with masseter muscle thickness.

Results

In the relaxing, the masseter was 9.8±1.3 mm in females and 11.3±1.2 mm in males. In the contracted state, it was 12.4±1.4 mm in females and 14.7±1.4 mm in males. Facial photography showed that bizygomatic facial width over facial height was correlated with masseter muscle thickness in both sexes in the relaxed state, and was statistically significantly correlated with masseter muscle thickness in males in the contracted state. In panoramic radiography, correlations were found between anterior angle length and posterior angle length and masseter muscle thickness in females, and between body length and posterior angle length, between anterior angle length and body length, between ramal length and body length, and between body length and condyle length in males.

Conclusion

Masseter muscle thickness was associated with facial and mandibular morphology in both sexes, and with age in males. Ultrasonography can be used effectively to measure masseter muscle thickness.

Intra-muscular haemangioma of the masseter: A clinical update and differential diagnosis of a rare entity

The intramuscular haemangioma (IMH) is a rare variant of unknown aetiology and comprises 0.8% of soft tissue haemangiomas. Less than 20% of IMHs occur in the craniofacial region of which the masseter is the most common site. It presents as a non-specific, painful soft tissue enlargement in young adults. Symptoms common to vascular lesions usually are absent. Due to the paucity of clinical symptoms, advanced imaging techniques like MRIs are needed to clinch a definitive pre-operative diagnosis. The therapeutic modalities mentioned in the literature range from total surgical excision to non-surgical methods like cryotherapy, sclerotherapy, embolization and feeder vessel ligation. We present a case of an intra-massetric IMH in a 16-year-old male which was treated by total surgical excision with a follow up of 3 years. We also stress on the differential diagnosis of intra-massetric lesions and the key findings of the various imaging modalities available for IMH.

Evaluation of lateral pterygoid muscles in painful temporomandibular joints by signal intensity on fluid-attenuated inversion recovery images

OBJECTIVES

Pathological changes of the lateral pterygoid muscle (LPM) have been investigated using various modalities, including magnetic resonance (MR) imaging and electromyography. Fluid-attenuated inversion recovery (FLAIR) is an MR sequence that we hypothesized can be used to evaluate abnormalities of the LPM. The purpose of this study was to analyze the FLAIR signal intensity of the LPM in painful temporomandibular joints (TMJs) and investigate the pathological changes of the muscle.

METHODS

The study was based on 149 TMJs of 77 patients who were referred for MR imaging of the TMJ. Patients rated their degree of pain during chewing and mouth opening using a visual analog scale (VAS). Regions of interest were placed over the superior and inferior heads of the LPM and gray matter on FLAIR sagittal images. Using the signal intensity of gray matter as a reference, the signal intensity ratio (SIR) of the LPM was calculated. Spearman's rank-correlation coefficient was used to analyze the correlation between the SIR and the VAS score (p < 0.05).

RESULTS

A significant correlation was present between the SIR on FLAIR images and the VAS score.

CONCLUSIONS

These results suggest that the FLAIR signal intensity of the superior and inferior heads of the LPM significantly increases as TMJ pain becomes more severe. Thus, FLAIR could be useful in assessing the relationship between the MR signals of the LPM and clinical symptoms.

Analysis of the blood supply to the post-fracture edentulous mandible: study by colour Doppler sonography

PURPOSE

This study assessed the arterial blood supply to the mandible of edentulous patients treated for mandibular fractures using colour Doppler ultrasound.

METHODS

The blood supply of edentulous patients surgically treated for mandibular fractures (group A) and edentulous fracture-free individuals (group B) was assessed. Only the fractured sides were evaluated in the first group (N = 17), whereas each side was evaluated in the second group (N = 20). The arterial flow of six sites was assessed. The systolic-peak maximum velocity (SPV), final diastolic velocity (FDV), resistive index (RI), pulsatility index (PI), acceleration and flow direction of each artery were obtained. Additionally, the presence of local vascular obstructive factors was evaluated. The differences between groups were analysed using the Kruskal-Wallis test, which was complemented by the Mann-Whitney test, for correlations between the degree of alveolar atrophy and the study factors (p < 0.050).

RESULTS

There was a significant decrease in the flow of certain arteries, especially the submental (SPV, p = 0.007, PI, p = 0.022, and acceleration, p = 0.015), in the fracture group. The facial artery in both groups showed lower values related to local obstructive factors (SPV, p = 0.001, FDV, p = 0.040, and PI, p = 0.030). The submental artery flow was higher (SPV, p = 0.006, and FDV, p = 0.009) in non-atrophic individuals.

CONCLUSIONS

There was a decreased flow mainly in the submental artery, but there were no cases of major vascular injury in edentulous patients treated for mandibular fractures.

Vascular mapping of the face: B-mode and doppler ultrasonography study

BACKGROUND

To analyze the face vascularization pattern using B-mode and Doppler ultrasonography, and also propose an arterial vessel mapping.

MATERIAL AND METHODS

The investigation was performed on 20 ultrasonography exams of facial vessels through linear and endocavitary transducers. We analyzed and determined the average values for diameters, peak systolic velocity and resistive index of the following arteries: external carotid, lingual, deep lingual, sublingual, facial, submental, inferior labial, superior labial, angular, maxillary inferior alveolar, mental, buccal, greater palatine, infraorbital, superficial temporal, transverse facial and frontal.

RESULTS

Data was obtained allowing the analysis of the tissue hemodynamics. We were able to map the vascularization of the face and it was possible to access three arteries of small diameter (0,60mm angular artery; 0,55mm greater palatine artery; 0,45mm infraorbital artery).

CONCLUSIONS

The results presented in this article are valid tool supporting the non-invasive mapping of facial vascularization.

Segmental masseteric flap for dynamic reanimation of facial palsy

The masseter muscle is one of the major chewing muscles and contributes to define facial contour. It is an important landmark for aesthetic and functional surgery and has been used for facial palsy reanimation or as source of donor motor nerve. We present an anatomic study to evaluate the possibility of using a muscle subunit for dynamic eye reanimation. Sixteen head halves were dissected under magnification to study the neurovascular distribution and determine safe muscle subunits; areas of safe/dangerous dissection were investigated. Once isolated, the arc of rotation of the muscular subunit was measured on fresh body to verify the reach to the lateral canthus. The patterns of neurovascular distribution and areas of safe dissection were identified; the anterior third of the muscle represents an ideal subunit with constant nerve and artery distribution. The muscle is too short to reach the lateral canthus; a fascia graft extension is needed. The information provided identified the main neurovascular branches and confirms the feasibility of a dynamic segmental flap. The need of efficient motor units for facial reanimation demands for different surgical options. A detailed anatomic description of the neurovascular bundle is mandatory to safely raise a functional motor subunit.

Arteriovenous malformation of the mandible and parotid gland

Arteriovenous malformations (AVMs) of the jaws are relatively rare, with fewer than 200 cases reported in the literature. Their real importance lies in their potential to result in exsanguination, which usually follows an unrelated treatment, such as tooth extraction, surgical intervention, puncture wound or blunt injury in involved areas, with the dentist unaware of the existence of the AVM. The present case illustrates an AVM in an 18-year-old female with swelling on the right side of the face. This case report is unique because although there was no history of bleeding episodes, thorough examination and investigation diagnosed it as high-flow vascular malformation. We ascertain the importance of dentists' awareness of the fatal outcome of these lesions and emphasize that, prior to performing any procedure, necessary investigations should always be done.

Objective sonographic measures for characterizing myofascial trigger points associated with cervical pain

OBJECTIVES

The purpose of this study was to determine whether the physical properties and vascular environment of active myofascial trigger points associated with acute spontaneous cervical pain, asymptomatic latent trigger points, and palpably normal muscle differ in terms of the trigger point area, pulsatility index, and resistivity index, as measured by sonoelastography and Doppler imaging.

METHODS

Sonoelastography was performed with an external 92-Hz vibration in the upper trapezius muscles in patients with acute cervical pain and at least 1 palpable trigger point (n = 44). The area of reduced vibration amplitude was measured as an estimate of the size of the stiff myofascial trigger points. Patients also underwent triplex Doppler imaging of the same region to analyze blood flow waveforms and calculate the pulsatility index of blood flow in vessels at or near the trigger points.

RESULTS

On sonoelastography, active sites (spontaneously painful with palpable myofascial trigger points) had larger trigger points (mean ± SD, 0.57 ± 0.20 cm(2)) compared to latent sites (palpable trigger points painful on palpation; 0.36 ± 0.16 cm(2)) and palpably normal sites (0.17 ± 0.22 cm(2); P < .01). Analysis of receiver operating characteristic curves showed that area measurements could robustly distinguish between active, latent, and normal sites (areas under the curve, 0.9 for active versus latent, 0.8 for active versus normal, and 0.8 for latent versus normal, respectively). Doppler spectral waveform data showed that vessels near active sites had a significantly higher pulsatility index (median, 8.3) compared to normal sites (median, 3.0; P < .05).

CONCLUSIONS

The results presented in this study show that myofascial trigger points may be classified by area using sonoelastography. Furthermore, monitoring the trigger point area and pulsatility index may be useful in evaluating the natural history of myofascial pain syndrome.

Topography of the arteries supplying the masseter muscle: Using dissection and Sihler's method

Various surgical procedures require surgeons to have detailed knowledge of the course of blood vessels in the masseter muscle, such as masseter muscle flap formation, mandibular angle resection, parotidectomy, and mandibular ramus osteotomy. Without this knowledge serious complications can occur, endangering the lives of patients. Occasionally, during routine dissections we sometimes encounter an additional branch. The purpose of this study was to provide a comprehensive detailed anatomic description of the blood supply of the masseter muscle. This will provide critical information for various surgical procedures. Twenty-five Korean cadavers were dissected and subjected to modified Sihler's method to reveal the branching patterns of the arteries surrounding the masseter muscle, and its intramuscular blood supply. The masseter can be supplied by seven branches from the external carotid artery. Among these, the masseteric branch from the deep temporal artery has not been described previously. This previously undescribed branch enters the medial surface of the masseter, turning medially around the anterior border of the ramus immediately after the branching point of the deep temporal artery. The branch originating from the transverse facial artery was the largest, and the branches originating from the external carotid artery and deep temporal artery were the smallest. Examination of intramuscular patterns revealed that the branches of the transverse facial artery were the most widely distributed. When considering arterial diameters and distribution areas, the branches of the transverse facial artery can be considered the main components of the seven branches supplying the masseter muscle.

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.

Intramuscular haemangioma of mylohyoid muscle: A case report

OBJECTIVE

To report a case of intramuscular haemangioma (IMH) with a rare presentation in the mylohyoid, with emphasis on the clinical appearance, and histologic characteristics of the lesion.

METHOD

Case report and review of the literature.

CONCLUSION

Neck swellings can often present a diagnostic dilemma, with a wide preoperative differential diagnosis. IMH are rare benign haemangiomas occurring within the skeletal muscle. They account for approximately 1% of all haemangiomas. These are uncommon in the head and neck region and occur most frequently in the trunk and extremities. In the head and neck, masseter and trapezius are the most common sites involved. Intramuscular haemangioma is seldom diagnosed preoperatively, perhaps due to unfamiliarity with this uncommon lesion and nonspecific clinical findings.

Analysis of the masseter muscle in patients with systemic sclerosis: a study by magnetic resonance imaging

OBJECTIVES

The aim of this study was to investigate the relationship between mandibular osteolysis and the T1 and T2 tissue signal strength and morphology of the masseter muscle in patients with systemic sclerosis (SS).

METHODS

All patients with SS underwent panoramic radiography to detect mandibular osteolysis. MRI of the masseter was performed on 15 patients with SS and 10 healthy control subjects.

RESULTS

All patients presented mean T1 values that were statistically equal. The patients with osteolysis presented mean T2 values that were the same as those of patients without osteolysis and normal individuals. The patients without osteolysis showed stronger T2 signals than did the normal individuals. The morphological analysis showed more atrophy, fatty replacement and rectified morphology in relation to the healthy subjects.

CONCLUSIONS

The patients with SS presented more atrophy, fat replacement and rectification than did the normal individuals. The T2 signal was significantly stronger among the patients with SS without osteolysis than among normal individuals and among patients with SS and osteolysis.

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.

Muscle thickness, bite force, and craniofacial dimensions in adolescents with signs and symptoms of temporomandibular dysfunction

Ultrasonography has been used to determine the association between muscle thickness, temporomandibular dysfuntion (TMD), facial morphology, and bite force. The aim of this study was to evaluate signs and symptoms (SS) of TMD using the craniomandibular index (CMI), masseter and anterior temporalis thickness, facial dimensions, and bite force in adolescents (12-18 years of age): 20 (10 males and 10 females) with SSTMD and 20 without (control, matched for age and gender). Ultrasonography was carried out using Just-Vision 200, and bite force measured with a pressure transducer. The measurements undertaken on the cephalograms included anterior (n-gn, n-Me, sp-gn) and posterior (S-tgo) facial dimensions, jaw inclination (NSL/ML), vertical jaw relationship (NL/ML), gonial angle (ML/RL), and overbite and overjet. The data were analysed with analysis of variance, Pearson's and Spearman's correlation and multiple regression. The SSTMD group showed a smaller bite force than the controls (P < 0.05). In the control group, bite force was negatively correlated with jaw inclination and overbite. There were negative correlations between anterior temporalis thickness and anterior facial dimensions; and positive correlations for masseter and anterior temporalis and posterior dimensions. In the SSTMD group, there were positive correlations for masseter and bite force, and anterior and posterior dimensions. Negative correlations were found for the masseter and temporalis muscles and jaw inclination and vertical jaw relationship. Multiple regression analysis showed that in the control group the overjet and jaw inclination contributed 50 per cent to the variance in bite force. In the SSTMD group, the dimensions of the masseter muscles during contraction contributed 39 per cent to the variance. The correlations between CMI and the craniofacial variables were more significant in the SSTMD group. The findings indicate that muscle thickness influences facial dimensions and bite force in adolescents with SSTMD.

The Use of Color Doppler Ultrasound in the Assessment of Vessels for Facial Transplantation

The facial artery has been proposed as the main vascular pedicle in facial transplantation. An anatomic study of 200 consecutive facial and transverse facial vessels in 100 normal individuals was performed using color Doppler ultrasound. The diameter and course of each facial vessel were measured at 3 fixed landmarks, and the branching pattern was documented up to the level of the nasal ala. The concomitant transverse artery and vein were similarly documented. The main branch of the facial artery was detected at the lower mandibular border in 99.5% (n = 199) of cases. The accompanying facial vein was found in 97.5% (n = 195) of cases, lateral to the artery in all cases. The transverse facial artery was present in 75.5% (n = 151) of cases, with the vein found in 58% (n = 116). When the facial artery was undetectable, there was transverse facial artery dominance. When the facial vein was absent, it was replaced with a transverse facial vein; this venous anomaly was accompanied by normal arterial supply pattern. This study is the first to describe the measurement of transverse facial vessels sonographically and confirms previous cadaveric studies of facial arterial and venous variation. Color Doppler can be used in the preoperative vascular assessment of both donor and recipient in facial transplantation.

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.

Quantifying labial blood flow using optical Doppler tomography

OBJECTIVES

Changes in the oral microvasculature occur in a variety of diseases. Optical Doppler tomography (ODT) combines laser Doppler flowmetry with optical coherence tomography (OCT) to produce high-resolution tomographic images of biological tissues that also detect the velocity and direction of blood flow. The objective of this study was to determine the feasibility of ODT to image labial blood flow. A prototype ODT imaging system was constructed that characterized and measured labial blood flow in healthy subjects.

MATERIALS AND METHODS

A prototype ODT instrument was constructed using a diode light source with a central wavelength of 1300 nanometers, a 40-nanometer spectral width and 2.4 microwatts output power. To verify the accuracy of the system, the flow rates of a phantom material (Intralipid) pumped through a capillary tube at various speeds was measured. To evaluate the clinical feasibility of the ODT prototye, the mucosal aspect of the upper and lower lips at the midline was imaged in 9 healthy volunteers. The sample arm of the instrument consisted of a fiberoptic probe with a 2-mm in diameter polished glass lens attached to the end. The probe was placed approximately 3 mm from the mucosal surface of the lip and oriented perpendicular to the surface. A motorized translation stage moved the fiber in a superior to inferior direction while the subject's head was stabilized by placing the chin into a chin rest. Imaging time for a 12-mm x 2.5-mm scan was approximately 64 seconds.

RESULTS

The phantom experiments revealed that accuracy of this novel ODT prototype to measure flow was within 5%. In vivo labial blood flow velocity ranged from 11.8 to 43.1 mm/second in the upper lip and 8.2 to 53.2 mm/second in the lower lip. There were no statistically significant differences between flow rates in the upper and lower lips. OCT images and Doppler velocity signals were successfully integrated producing in vivo images of labial blood in all of the subjects (15 images). The resulting cross-sectional images revealed microscopic details of labial structures and, to the best of our knowledge, are the first ODT images of the labial microvasculature.

CONCLUSIONS

The results of this in vivo study prove the feasibility of ODT to quantify labial blood flow and produce high spatial resolution images specifically localizing vessels anatomically. ODT provides both flow speed and flow direction information. ODT is noninvasive and offers the advantages of high volumetric flow sensitivity.

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.