Use of Superficial Temporal Fascia Flap for Treatment of Postradiation Trismus: An Innovation.

Post radiation trismus severely reduces the quality of life. Radiation causes fibrosis of muscles of mastication resulting in severe restriction of mouth opening. Treatment options are limited as most of the local flaps are in the radiation zone. The present case is the first case in existing literature where, following the release of fibrosis secondary to radiation, superficial temporal fascia (STF) was used to cover the defect with excellent results and no recurrence after a year of follow up.

Masticatory Muscles Dysfunction after CT-guided Percutaneous Trigeminal Radiofrequency Thermocoagulation for Trigeminal Neuralgia: A Detailed Analysis.

OBJECTIVE: The aim of this study was to investigate the severity and the natural course of masticatory muscles weakness that developed after CT-guided percutaneous trigeminal radiofrequency thermocoagulation (PT-RFT) for the treatment of idiopathic trigeminal neuralgia (ITN). METHODS: Twenty-seven patients with ITN were treated by CT-guided percutaneous trigeminal radiofrequency thermocoagulation. Each patients' occlusal function and surface electromyographic (sEMG) activity of the ipsilateral anterior temporalis (TA) and masseter muscles (MM) at mandibular postural position (MPP), and during a fast maximum voluntary clenching (MVC) from MPP to intercuspal position (ICP), were simultaneously recorded by the T-Scan III system and Bio-pak sEMG III system before (baseline), 3 days, 3 months, and 12 months after procedure. The incidence, degree, and prognosis of masticatory muscles dysfunction related to trigeminal nerve motor-branch injury were analyzed. RESULTS: Three days and 3 months after procedure, both the occlusal symmetry and the sEMG activity of ipsilateral TA and MM became significantly decreased compared to the baseline (P < 0.05). However, they demonstrated a gradual improvement toward preoperative values in follow-up, returning to complete in 23 patients at 12 months after procedure. None reported permanent masticatory paralysis. Pain relief was most significant on the third day after procedure. At the final clinical visit, a pain-free status was observed in 25 patients (92.6%). Meanwhile, the intensity of facial dysesthesia was mildest, whereas there were statistic differences compared with baseline. CONCLUSION: CT-guided PT-RFT for ITN remains an effective and safe surgical procedure, but there is a high rate of temporary masticatory dysfunction during a short time after procedure, appearing to be reversible in a period of 12 months.

The Application of Radiofrequency Waves in Supportive Treatment of Temporomandibular Disorders.

In recent years, the number of patients applying for prosthetic treatment due to temporomandibular joint disorders (TMD) has been increasing. The main methods for treating disorders are the use of occlusal splints and physiotherapeutic rehabilitation as supportive treatment. Radio waves are electromagnetic waves with radiation frequency between 3 Hz and 3 THz, used for physiotherapeutic treatment of skeletal muscle relaxation in the range of 3 to 6 MHz. The rehabilitation effect of these waves is based on diathermy by means of high-voltage quick alternating current. Aim. The aim of the study was to evaluate the influence of radiofrequency waves on the pain of the masticatory muscles in the course of TMD and the usefulness of these procedures in the supporting treatment of these disorders. Materials and Methods. Patients aged 19 to 45 years, of both sexes, reported to the Consulting Room of TMD at the Institute of Dentistry in Krakow to undertake prosthetic treatment of TMD (I a-according to RDC/TMD). Study group (SG) consists of 20 patients who had 10 supportive treatments with radiofrequency currents. In the case of application of radiation to the muscle area, the energy was 20 J to the area of the masticatory muscles, the frequency was 3 MHz, bipolar technique, the duration of the procedure was 10 minutes, and the coupling substance was a gel for ultrasound examinations. The control group (CG) consisted of 20 patients who had 10 supportive treatments with sonophoresis procedures. For the area of masticatory muscles, 0.9 W/cm2 treatments were applied, the duty factor was 80%, the treatment time was 10 minutes, and the medical substance was 25% Voltaren gel. Results. Analysis of the results of the first clinical examinations (axis I) conducted in both groups shows a homogeneous clinical material and similar results. The second clinical examination revealed improved clinical parameters, but it showed a greater improvement in the SG. In the SG, the mean level of VAS was 6.25, and the extreme values were 5.9-0.14, the median was 2.15, and the standard deviation was 1.54. In the CG, the average value of VAS was 6.20 (peak of 5.2-0.7), the median was 2.4, and the standard deviation was 1.87. Summary. The search for new methods of supportive treatment of TMD is an important research direction due to the complex etiology of this disease and the lack of an explicit treatment algorithm. Conclusion. The results of our own research clearly indicate that the use of the radiofrequency waves brings pain relief and improvement of clinical parameters to a greater extent than in sonophoresis. It can be a very important new method in supportive treatment of TMD. Research needs to be continued.

Evaluation of the effectiveness of infrared light-emitting diode photobiomodulation in children with sleep bruxism: Study protocol for randomized clinical trial.

BACKGROUND: Sleep bruxism is a masticatory muscle activity characterized as rhythmic (phasic) or nonrhythmic (tonic). In children and adolescents, etiological factors, such as breathing pattern and sleep quality, have recently been addressed in studies investigating sleep bruxism. New therapies for adults, such as botulinum toxin, have been investigated, but such techniques are not applicable for individuals in the growth and development phase. METHODS: The participants will be 76 children, which will be randomly allocated to a control group, that is group 1, absence of bruxism; group 2, children with bruxism treated with infrared light-emitting diode (LED); and group 3, bruxism treated with occlusal splint. All participants will be submitted to a clinical evaluation to evaluate muscle activity and salivary biomarkers, before and after treatments. Muscle activity will be verified by electromyography of muscles mastication, masseter and temporal, and salivary biomarkers observed will be cortisol and dopamine levels. DISCUSSION: Photobiomodulation therapy has piqued the interest of researchers, as this noninvasive method has demonstrated positive results in problems related to muscle tissues. This document describes the protocol for a proposed study to evaluate morphological and psychosocial aspects in children and adolescents with awake bruxism and their responses to photobiomodulation therapy with infrared LED. CLINICAL TRIALS:.

Use of a novel atlas for muscles of mastication to reduce inter observer variability in head and neck radiotherapy contouring.

PURPOSE/OBJECTIVE(S): Trismus is caused by injury to the masticatory muscles resulting from cancer or its treatment. Contouring these muscles to reduce dose and radiation related trismus can be problematic due to interobserver variability. This study aimed to evaluate the reduction in interobserver variability achievable with a new contouring atlas. MATERIALS/METHODS: The atlas included: medial and lateral pterygoids (MP, LP), masseter (M) and temporalis (T) muscles, and the temporo-mandibular joint (TMJ). Seven clinicians delineated five paired structures on CT scans from 5 patients without the atlas. After ≥5 weeks, contouring was repeated using the atlas. Using contours generated by the clinicians on the same 5 CT scans as reference, dice similarity coefficient (DSC), mean distance-to-agreement (DTA) and centre of mass (COM) difference were compared with and without the atlas. Comparison was also performed split by training grade. Mean and standard deviation (SD) values were measured. RESULTS: The atlas reduced interobserver variability for all structures. Mean DTA significantly improved for MP (p = 0.01), M (p < 0.01), T (p < 0.01) and TMJ (p < 0.01). Mean DTA improved using the atlas for the trainees across all muscles, with the largest reduction in variability observed for the T (4.3 ±â€¯7.1 v 1.2 ±â€¯0.4 mm, p = 0.06) and TMJ (2.1 ±â€¯0.7 v 0.8 ±â€¯0.3 mm, p < 0.01). Distance between the COM and interobserver variability reduced in all directions for MP and T. CONCLUSION: A new atlas for contouring masticatory muscles during radiotherapy planning for head and neck cancer reduces interobserver variability and could be used as an educational tool.

Photobiomodulation versus light-emitting diode (LED) therapy in the treatment of temporomandibular disorder: study protocol for a randomized, controlled clinical trial.

BACKGROUND: Temporomandibular disorder (TMD) is described as a subgroup of orofacial pain with a set of signs and symptoms that involve the temporomandibular joint, masticatory muscles, ears, and neck. TMD can occur unilaterally or bilaterally and approximately 70% of the population is affected with at least one sign. The disorder progresses with orofacial pain, muscle pain involving the masticatory and cervical muscles, joint noises (clicks and pops), joint block, mandibular dysfunction, and headache. The etiology can be abnormal occlusion and/or posture, trauma involving local tissues, repetitive microtrauma, parafunctional habits, and an increase in emotional stress. Studies have demonstrated that phototherapy is an efficient option for the treatment of TMD, leading to improvements in pain and orofacial function. METHODS: The aim of the proposed study is to compare the effects of two sources of photobiomodulation in individuals with TMD. A randomized, controlled, double-blind, clinical trial is proposed, which will involve 80 individuals aged 18-65 years allocated to either a laser group or light-emitting diode (LED) group submitted to 12 sessions of phototherapy. The Research Diagnostic Criteria for TMDs will be used to evaluate all participants. Pain will be measured using the visual analog scale and maximum vertical mandibular movement will be determined with the aid of digital calipers. DISCUSSION: This study compares the effects of two modalities of laser therapy on the pain and orofacial function of patients with TMD dysfunction. Photobiomodulation and LED therapy are treatment options for reducing the inflammatory process and pain as well as inducing the regeneration of the target tissue. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03257748 . Registered on 8 August 2017.

A mobilization regimen to prevent mandibular hypomobility in irradiated patients: an analysis and comparison of two techniques.

Radiotherapy, when used in head and neck cancer treatment, can produce side effects in the patients, such as decreased salivary production, xerostomia, opportunistic infections, radiation caries, dysphagia, local discomfort and the limitation of mouth opening. The aim of this study was to evaluate the amplitude of mouth opening in patients before and immediately after the completion of radiotherapy, comparing the effectiveness of two physiotherapy exercises. The irradiated sites included the masticatory muscles. The results demonstrated that there were no statistically significant differences between the two instituted exercises; however there was a trend towards better clinical results in group 2. The amplitude of mouth opening showed a trend towards reduction, but this was not statistically significant. When the pterygoid and sternocleidomatoid muscles were included in the irriated field, patients were observed to have more morbidity. This indicates the great importance of these muscles in mouth opening. Based on the results obtained within this study, it is not possible to conclude that physiotherapy exercies are efficacious in preventing trismus. Future longitudinal studies are required to verify the onset of trismus in radiotherapy patients.

The motor cortex is involved in reflexive compensatory adjustment of speech articulation.

Although speech articulation relies heavily on the sensorimotor processing, little is known about its brain control mechanisms. Here, we investigate, using transcranial magnetic stimulation, whether the motor cortex contributes to the generation of quick sensorimotor responses involved in speech motor coordination. By applying a jaw-lowering perturbation, we induced a reflexive compensatory upper-lip response, which assists in maintaining the intact labial aperture in the production of bilabial fricative consonants. This reflex response was significantly facilitated by subthreshold transcranial magnetic stimulation over the motor cortex, whereas a simple perioral reflex that is mediated only within the brainstem was not. This suggests that the motor cortex is involved in generating this functional reflexive articulatory compensation.

Involvement of reticular neurons located dorsal to the facial nucleus in activation of the jaw-closing muscle in rats.

The location of excitatory premotor neurons for jaw-closing motoneurons was examined by the use of electrical and chemical stimulation and extracellular single-unit recording techniques in the anesthetized rat. Single-pulse electrical stimulation of the supratrigeminal region (SupV) and the reticular formation dorsal to the facial nucleus (RdVII) elicited masseter EMG response at mean (+/-SD) latencies of 2.22 +/- 0.59 ms and 3.10 +/- 1.14 ms, respectively. Microinjection (0.1-0.3 microl) of glutamate (50 mM) or kainate (0.5-100 microM) into RdVII increased masseter nerve activity in artificially ventilated and immobilized rats by 30.2 +/- 40.5% and 50.7 +/- 46.8% compared to baseline values, respectively. Forty reticular neurons were antidromically activated by stimulation of the ipsilateral trigeminal motor nucleus (MoV). Twenty neurons were found in RdVII, and the remaining 20 neurons were located in SupV, or areas adjacent to SupV or RdVII. Eleven neurons in RdVII responded to at least either passive jaw opening or light pressure applied to the teeth or tongue. Nine neurons responded to passive jaw opening. Five of the nine neurons responded to multiple stimulus categories. A monosynaptic excitatory projection from one neuron in RdVII was detected by spike-triggered averaging of the rectified masseter nerve activity. We suggest that reticular neurons in RdVII are involved in increasing masseter muscle activity and that excitatory premotor neurons for masseter motoneurons are likely located in this area. RdVII could be an important candidate for controlling activity of jaw-closing muscles via peripheral inputs.

A rat model of radiation injury in the mandibular area.

BACKGROUND: Radiation technology focuses on delivering the radiation as precisely as possible to the tumor, nonetheless both acute and long-term damage to surrounding normal tissue may develop. Injuries to the surrounding normal tissue after radiotherapy of head and neck cancer are difficult to manage. An animal model is needed to elucidate good treatment modalities. The aim of this study was to establish a rat model where a certain radiation dose gives reproducible tissue reactions in the mandibular area corresponding to injuries obtained in humans. METHOD: The left mandible of male Sprague Dawley rats was irradiated by external radiotherapy (single fraction 15 Gy, total dose 75 Gy) every second week five times. Endpoint was six weeks after last radiation treatment, and the test group was compared to non-irradiated controls. Morphological alterations of the soft tissues, bone and tooth formation, as well as alterations of salivation, vascularity and collagen content were assessed. An unpaired, non-parametric Mann-Whitney test was used to compare the statistical differences between the groups. RESULTS: Analysis of the soft tissues and mandible within the radiation field revealed severe unilateral alopecia and dermatitis of the skin, extensive inflammation of the submandibular gland with loss of serous secretory cells, hyperkeratinization and dense connective fiber bundles of the gingival tissue, and disturbed tooth development with necrosis of the pulp. Production of saliva and the vascularity of the soft tissues were significantly reduced. Furthermore, the collagen fibril diameter was larger and the collagen network denser compared to non-irradiated control rats. CONCLUSION: We have established an animal model of radiation injury demonstrating physiological and histological changes corresponding to human radiation injuries, which can be used for future therapeutic evaluations.

Restricted opening of the mouth with an extra-articular cause in children.

Restricted opening of the mouth with an extra-articular cause (ROMEC) can have very different aetiologies. A series of 6 children, who have been operated on under 4 different diagnoses, are presented. Excluded are common problems such as recent trauma and posttraumatic scarring, craniomandibular dysfunction or elongated coronoid process, and also tumours. Problems of establishing the diagnosis, surgical treatment, postoperative physiotherapy and timing are discussed. It is shown that none of the cases is a perfect result, some outcomes are even very disappointing. It is therefore concluded that absolute trismus should be treated independently of age. The result expected will be mediocre. For final correction it is suggested that the operator should wait preferably until the second growth spurt has passed. The same goes for children presenting primarily with a mouth opening greater than 20 mm.

Effect of low-level laser therapy on the post-surgical inflammatory process after third molar removal: study protocol for a double-blind randomized controlled trial.

BACKGROUND: Low-level laser therapy (LLLT) has been shown to modulate the inflammatory process without adverse effects , by reducing pain and swelling and promoting the repair of damaged tissues. Because pain, swelling and muscle spasm are complications found in virtually all patients following oral surgery for the removal of impacted teeth, this model has been widely used to evaluate the effects of LLLT on the inflammatory process involving bone and, connective tissue and the muscles involved in mastication. METHODS/DESIGN: After meeting the eligibility criteria, 60 patients treated at a Specialty Dental Center for the removal of impacted lower third molars will be randomly divided into five groups according to the type of laser therapy used at the end of surgery (intraoral irradiation with 660 nm laser; extraoral irradiation with 660 nm laser; intraoral irradiation with 808 nm laser; extraoral irradiation with 808 nm laser and no irradiation). To ensure that patients are blinded to the type of treatment they are receiving, the hand piece of the laser apparatus will be applied both intraorally and extraorally to all participants, but the device will be turned on only at the appropriate time, as determined by the randomization process. At 2 and 7 days after surgery, the patients will be evaluated by three blinded evaluators who will measure of swelling, mouth opening (muscle spasm evaluation) and pain (using two different pain scales). The 14-item Oral Health Impact Profile (OHIP-14) will be used to assess QOL. All data will be analyzed with respect to the normality of distribution using the Shapiro-Wilk test. Statistically significant differences between the experimental groups will be determined using analysis of variance, followed by a suitable post hoc test, when necessary. The significance level will be set at α = 0.05. DISCUSSION: The lack of standardization in studies with regard to the samples, methods and LLLT parameters complicates the determination of the actual effect of laser therapy on this model. The present study aims to provide a randomized, controlled, double-blind trial to compare four different LLLT parameters in relation to the outcomes of pain, swelling and muscle spasm following surgery for the extraction of impacted third molars and evaluate the effects os surgery on patients' quality os life (QOL). TRIAL REGISTRATION: Brazilian Registry of Clinical Trials - Rebec (RBR-6XSB5H).

Mandibular bone changes induced by head and neck radiotherapy.

CONTEXT: The mandible is inevitably affected by radiation during radiotherapy of head and neck cancers. Surveys have shown that most of the emphasis has been on osteoradionecrosis (ORN), while the other bony changes occurring in this area have been largely ignored. AIMS: In this study we examine the radiologic changes in the mandible of irradiated patients using panoramic radiography and compare it with the mandible in non-irradiated cases. MATERIALS AND METHODS: Mandibular bone changes of 48 patients who had received therapeutic radiation for head and neck cancer were assessed. We measured the width of the cortex and the width of the mandibular canal on panoramic radiographs and assessed the changes by comparison with the mandibular bones of non-irradiated subjects. Clinical evaluations were performed for assessing maximum jaw opening, masticatory muscle tenderness, and presence of mucosal ulcers and/or exposed bone in the oral cavity. STATISTICAL ANALYSIS: Paired t-test, Chi-square test, and Mann-Whitney test were used for statistical analysis. P < 0.05 was taken to indicate statistical significance. RESULTS: There was no evidence of mucosal ulceration or exposed bone in irradiated patients. There was significant relationship between the number of years after radiotherapy and the degree of limitation of mouth opening (P = 0.000). Receipt of concurrent chemotherapy did not seem to have any additive effect on the width of mandibular canal or the thickness of the mandibular cortex. CONCLUSION: Reduction in the width of the mandibular cortex and dimensions of the inferior alveolar canal could be considered as one of the effects of head and neck radiotherapy.

Avaliação da abertura bucal em pacientessubmetidos à radioterapia de cabeça e pescoço / Evaluation of mouth opening in patients undergoing head and neck radiotherapy

A radioterapia de cabeça e pescoço quando direcionada à articulaçãotemporomandibular e músculos da mastigação, pode provocar sequelas como redução daamplitude de abertura bucal e trismo, que, muitas vezes, pode ser irreversível.Objetivo: comparar a amplitude de abertura bucal, antes e após a radioterapia da regiãode cabeça e pescoço.Metodologia: foram selecionados 30 pacientes com diagnóstico de tumores malignos decabeça e pescoço para serem submetidos à mensuração da abertura bucal 30 dias antes daradioterapia, e 90 dias após. Também foram observadas as características gerais comotipo histológico do tumor e dose de radioterapia.Resultados: a idade média da amostra foi de 58 anos, sendo que 80,76% eram do sexomasculino e 19,24% do feminino. Na primeira avaliação encontrou‐se limitação deabertura bucal (35,08±8,74), e 90 dias após a radioterapia houve aumento da limitação deabertura bucal (31,5±10,42), porém, sem mostrar significância estatística (p≤0,061).Conclusão: não houve agravamento da limitação de abertura bucal após três meses deradioterapia...

When temporomandibular joint and muscles of mastication are in the fieldof radiation, trismus and restriction of mouth opening are common and often irreversiblesequelae.Aim: compare mouth opening before and after head and neck radiotherapy.Methodology: thirty patients with head and neck malignant tumors were chosen to havetheir mouth opening measured 30 days before and 90 days after radiotherapy. Generalcharacteristics as histological type of the tumor and radiotherapy dose were alsoevaluated.Results: the mean age of the sample was 58 years, 21 subjects (80.76%) were male, and 5(19.24%) were female. At the first evaluation, we found mouth opening restriction(35.08±8.74) and ninety days after radiotherapy the mouth opening increased (31.5±10.42),but without statistical significance (p≤0.061).Conclusion: the mouth opening did not worse after 3 months of radiotherapy...

[Laser therapy in temporomandibular dysfunction (soft laser application points)]. / Laserterapia en las disfunciones témporo-mandibulares (puntos de aplicación del láser blando).

It is work out and discuss one of the principal problems in the laser therapy use during the TMJ dysfunction treatment: the determination of the application points for the soft-laser stay, detailing the position of some of them that are essentials to obtain the objectives of this type of treatment.

The physiological effects of radiotherapy on oral tissue.

An increasing number of head and neck cancer patients are undergoing radiotherapy along or in conjunction with other treatment modalities. Radiotherapy extending over a period of weeks produces a variety of clinical manifestations. This article discusses the physiological changes that occur due to radiotherapy to elucidate the changes seen clinically.

Mobilization regimens for the prevention of jaw hypomobility in the radiated patient: a comparison of three techniques.

This study evaluated and compared the Therabite Jaw Motion Rehabilitation System (Therabite Corporation, Bryn Mawr, PA) to tongue blades as a technique for maintaining and/or improving mandibular range of motion in post-irradiated patients. Three groups of patients were evaluated and compared: 1) unassisted exercise, 2) mechanically assisted mandibular mobilization with stacked tongue depressors combined with unassisted exercise, and 3) the Therabite System combined with unassisted exercise. The initial average maximum incisal opening (MIO) for the study population was 21.6 mm, and did not vary significantly among the groups. Measurements were recorded at 2-week intervals for 10 weeks. At week 6 and thereafter, the net increase in MIO of group 3 (13.6 mm [+/- 1.6 mm]) was significantly greater than group 1 (6.0 mm [+/- 1.8 mm]) and group 2 (4.4 mm [+/- 2.1 mm]) (P < .05). The rate of improvement leveled after 4 week in group 1 and group 2. However, the rate of gain in MIO in the Therabite group (group 3) remained constant at 10 weeks. There was no statistical difference between groups 1 and 2.