Localization of Maxillary Artery for Cerebral Revascularization: L-Shaped Perpendicular Two-Step Drilling Technique Stretching from the Foramen Ovale to Rotundum.

BACKGROUND: The use of the maxillary artery (MA) as a donor has increasingly become an alternative method for cerebral revascularization. Localization difficulties emerge due to rich infratemporal anatomical variations and the complicated relationships of the MA with neuromuscular structures. We propose an alternative localization method via the interforaminal route along the middle fossa floor. METHODS: Five silicone-injected adult cadaver heads (10 sides) were dissected. Safe and effective localization of the MA was evaluated. RESULTS: The MA displayed anatomical variations in relation to the lateral pterygoid muscle (LPM) and the mandibular nerve branches. The proposed L-shaped perpendicular 2-step drilling technique revealed a long MA segment that allowed generous rotation to the intracranial area for an end-to-end anastomosis. The first step of drilling involved medial-to-lateral expansion of foramen ovale up to the lateral border of the superior head of the LPM. The second step of drilling extended at an angle approximately 90° to the initial path and reached anteriorly to the foramen rotundum. The MA was localized by gently retracting the upper head of the LPM medially in a posterior-to-anterior direction. CONCLUSIONS: Considering all anatomical variations, the L-shaped perpendicular 2-step drilling technique through the interforaminal space is an attainable method to release an adequate length of MA. The advantages of this technique include the early identification of precise landmarks for the areas to be drilled, preserving all mandibular nerve branches, the deep temporal arteries, and maintaining the continuity of the LPM.

Arthroscopic assisted release of lateral pterygoid versus scarification of retrodiscal tissue in management of internal derangement of temporomandibular joint-A randomized clinical trial.

The purpose of this study was to compare the effectiveness of arthroscopic-assisted lateral pterygoid muscle release versus scarification of retrodiscal tissues in the treatment of temporomandibular joint internal derangement. A prospective, comparative, randomized clinical trial involved 16 patients with TMJ internal derangement. Arthroscopic assisted release of lateral pterygoid muscle was assigned to one group of patients (Group I). Group II patients received arthroscopic assisted scarification of retrodiscal tissues. Data collected through functional examination including visual analogue scale (VAS), maximum mouth opening, lateral excursion, and clicking sound immediately and after 3, 6, and 12 months. Pre- and post-operative MRI was used to assess disc position. The VAS scores decreased in both groups at the end of the follow-up period (0.45 vs 6.75, and 1.13 vs 6.50 in group I and II respectively; P<0.001). The maximum mouth opening improved to 32.9.50 ± 1.69 mm in group I, and 30.49 ± 0.93 in group II (P<0.001). Lateral excursion improved in both groups (P<0.001). Clicking sounds disappeared in all patients. Within the limitations of the study, it seems that arthroscopic assisted release of lateral pterygoid and scarification of retrodiscal tissues may be beneficial in management of anteriorly displaced discs that don't respond to conservative treatments.

An Unusual Case of Severe Trismus After Craniotomy.

Myositis ossificans Traumatica (MOT) is a non-neoplastic, heterotrophic ossifying disease process in muscle and soft tissue rarely involving the craniofacial area. Treatment depends on the extent of ossification and functional limitations. We present the first case of MOT of the temporalis muscle following neurosurgical intervention. This is the case of a 28-year-old male patient who underwent numerous neurosurgical interventions and reported progressive trismus following these interventions. Imaging demonstrated a right temporal region radio-opacity consistent with ossification of the temporalis muscle. The patient underwent coronoidectomy with excision of the ossified right temporalis muscle and reconstruction with an anterolateral thigh adipofascial vascular free flap. Postoperatively, he maintained intact function with increased incisal opening and no cosmetic defects. Limited mouth opening after the neurological procedure has a wide differential, and MOT must be considered. Surgical repair and reconstruction are multifaceted problems. Free flap reconstruction should be considered in multiple operated patients.

Osteoplasty of Medial Temporomandibular Joint Wall. A New Strategy for Treating Disc Displacement.

INTRODUCTION: Numerous factors have been indicated as possible causes of alterations in the articular disc of the temporomandibular joint (TMJ). The main aim of the present study was to demonstrate the effectiveness of arthroscopic osteoplasty of the medial TMJ wall associated with myotomy of the superior head of the lateral pterygoid muscle for treating TMJ internal derangement. MATERIAL AND METHODS: A retrospective and comparative study was performed analyzing patients diagnosed with TMJ internal derangement and underwent TMJ arthroscopic surgery in our Hospital. These patients presented signs and symptoms of TMJ internal derangement along with pathological magnetic resonance imaging images, and underwent either arthroscopic osteoplasty of the medial TMJ and myotomy of lateral pterygoid muscle (group 1) or arthroscopic eminoplasty (group 2) in our center. RESULTS: The sample consisted of 109 patients (21 male, 88 females) who agreed to voluntarily participate in our study. The results revealed that the patients who had undergone arthroscopic osteoplasty of the medial TMJ and myotomy of lateral pterygoid muscle showed better outcomes in terms of pain reduction when compared with patients who had undergone arthroscopic eminoplasty. No statistically significant differences were found between the 2 groups in terms of postoperative mouth opening. CONCLUSIONS: Arthroscopic osteoplasty of the medial and anterior medial wall of TMJ associated with arthroscopic myotomy of the SLEM represent an effective treatment option for TMJ internal derangement even in advanced stages (Wilkes IV and V).

Surgical anatomy of the lingual nerve for palate surgery: where is located and how to avoid it.

PURPOSE: To describe the anatomic relationship of the lingual nerve with the lateral oropharyngeal structures. METHODS: An anatomic dissection of the lateral oropharyngeal wall was conducted in eight sides from four fresh-frozen cadaveric heads. Small titanium clips were placed along the lingual nerve and the most anterior and medial border of the medial pterygoid muscle. Radiological reconstructions were employed for optimal visualization; the coronal view was preferred to resemble the surgical position. The distance between the lingual nerve and the medial pterygoid muscle at its upper and lower portion was measured radiologically. The trajectory angle of the lingual nerve with respect to the pterygomandibular raphe was obtained from the intersection between the vector generated between the clips connecting the upper and lower portion of the medial pterygoid muscle with the vector generated from the lingual nerve clips. RESULTS: The mean distance from the upper portion of the medial pterygoid muscle and superior lingual nerve clips was 10.16 ± 2.18 mm (mean ± standard deviation), and the lower area of the medial pterygoid muscle to the lingual nerve was separated 5.05 ± 1.49 mm. The trajectory angle of the lingual nerve concerning to the vector that describes the upper portion of the most anterior and medial border of the medial pterygoid muscle with its lower part was 43.73º ± 11.29. CONCLUSIONS: The lingual nerve runs lateral to the lateral oropharyngeal wall, from superiorly-inferiorly and laterally-medially, and it is closer to it at its lower third.

Lateral Pterygoid Muscle Ossification After Intraoral Condylectomy.

PURPOSE: Lateral pterygoid muscle ossification has not been reported in condylectomy patients. This study aimed to explore the incidence, risk factors, and imaging characteristics of 38 cases with lateral pterygoid muscle ossification among 54 patients after condylectomy via intraoral approach. METHODS: This retrospective study included 54 patients following simultaneous orthognathic surgery and condylectomy with coronoid process resection via intraoral approach. The authors evaluated the preoperative, 1 week, 6 months, and 1 year or more postoperative computed tomographic (CT) scans for the presence of lateral pterygoid muscle ossification and its characteristics. Sex, age at the time of surgery, disease course, affected side, preoperative alkaline phosphatase, pathology diagnosis, the height of the removed condyle, condylar shape, operator, preoperative temporomandibular joint movement, and clinical symptoms were assessed as risk factors for ossification. RESULTS: No incidence of lateral pterygoid muscle ossification was found on preoperative CT images. Various small-size osseous masses were observed in the lateral pterygoid muscles on postoperative 6 months CT images in 38/54 patients (70.37%) after condylectomy. But no apparent enlargement of the osseous masses was found. No patients complained of clinical discomfort or functional disorder during the follow-up period (23.11 ± 13.16 months). No significant risk factors for ossification were found. CONCLUSIONS: Lateral pterygoid muscle ossification is relatively common in patients after condylectomy via intraoral approach. However, its enlargement is self-limited and remains stable 6 months after surgery. it has no adverse effects on the temporomandibular joint functional movement.

Biomechanical analysis of a temporomandibular joint prosthesis for lateral pterygoid muscle reattachment.

OBJECTIVE: To analyze the biomechanical properties of a novel temporomandibular joint (TMJ) prosthesis with an attachment area for the lateral pterygoid muscle (LPM). STUDY DESIGN: Three prosthesis models were created and compared using finite element analysis for the displacement, stress, and strain when simulating the maximum bite force loading. A verification experiment and a compression test were conducted. RESULTS: The displacement, stress, and strain of the novel TMJ prosthesis were larger than the solid condylar neck prosthesis and similar to the slotted condylar neck prosthesis, but the values were far less than the yield strength of titanium alloy. The maximum stress and strain in the novel TMJ prosthesis was concentrated in the inner and boundary areas of the LPM reattachment region beside the thinnest part of the prosthesis neck. The difference in the strain values measured using the verification test and those using finite element analysis was <20%. Compression testing of the novel TMJ prosthesis revealed that the mandible fractured when the force reached 588.97 N, whereas the prosthesis itself did not break or deform. CONCLUSIONS: The mechanical distribution of the novel prosthesis was feasible under maximum bite force for potential clinical application.

Three-dimensional attachment morphometry and volumetric changes of masticatory muscles after free fibular flap reconstruction of the mandibular condyle.

This retrospective case-series study aimed to elucidate the three-dimensional attachment morphometric features and to quantify the volumetric changes of the masticatory muscles following free fibular flap reconstruction of the mandibular condyle. Navigation software (iPlan, version 3.0; Brainlab) was used to perform delineation and volumetric measurement of the masticatory muscles using DICOM data. In total, 30 patients were included in this retrospective case series. In 25 cases (83.33%), the lateral pterygoid muscle achieved reattachment within 6 months postoperatively. The medial pterygoid muscles on the affected side achieved ectopic attachment in all cases. However, masseter reattachment on the affected side was achieved in only three cases. On the normal side, the volumes of lateral pterygoid muscle, medial pterygoid muscle, and masseter had recovered to almost preoperative levels at 1 year postoperatively. On the affected side, the volume of medial pterygoid muscle had decreased significantly (p = 2.4e-04) at 3 months postoperatively. The volumes of lateral pterygoid muscle and masseter showed mild decreases at 3 months postoperatively, but these were not significant (p = 0.52 and p = 0.05 for the pterygoid muscle and masseter, respectively). At 6 months after surgery, with the exception of the volume of the lateral pterygoid muscle (p = 0.06), the total volume of the masticatory muscles decreased significantly on the affected side. The volumes of lateral pterygoid muscle, medial pterygoid muscle, and masseter showed significant decreases at 1 year postoperatively (p = 0.03, p = 4.7e-08, and p = 1.1e-05, respectively) on the affected side. The postoperative volumes of the masseter, medial pterygoid, and lateral pterygoid muscles showed significant decreases due to the loss of reattachment. The results of this study may not help to ascertain whether reattachment of masticatory muscles will lead to better function. As a consequence, clinical trials of higher quality are needed.

Study on the lateral pterygoid muscle status after artificial temporomandibular joint replacement.

The purpose of this study was to explore the status of the lateral pterygoid muscle (LPM) after detachment in artificial temporomandibular joint replacement (TJR) surgery. Patient clinical and computed tomography imaging data were collected before and after unilateral artificial TJR with LPM detachment. The volume of the LPM on the operated and unoperated sides was measured before and after surgery (at 1, 3, 6, 12 months) using ProPlan CMF 3.0 software. The volumes of the LPM on both sides, the patient's mandibular movements, quality of life (QoL), and pain and diet scores (visual analogue scales) were evaluated and compared at the different follow-up stages. Ten patients were included in the study. After surgery, the volume of the operated LPM was significantly reduced to 60.78% at 3 months (P=0.007), and gradually stabilized to 51.58% at 6 months (P=0.025) and 54.68% at 1 year postoperative (P=0.002). There were no significant LPM volume changes on the unoperated side (P=0.67). Lateral movement of the operated joint was significantly reduced (P=0.021) and correlated with the LPM volume change after surgical detachment (P=0.042). The LPM shrank after detachment in the artificial TJR surgery and the muscle detachment affected the movement of the replaced joint.

Total Temporomandibular Joint Prosthetic Reconstruction: The Importance of Lateral Pterygoid Muscle Reattachment to Lateral Excursive and Protrusive Mandibular Movement.

Severe temporomandibular joint (TMJ) disorders result in structural changes that can significantly and negatively impact the jaw and airway, resulting in pain, difficulty chewing, dietary restrictions, sleep apnea, and other functional changes.1 For more than 5 decades, alloplastic total TMJ replacement has been used to treat end-stage intra-articular TMJ disorders. Commonly accepted measures of postsurgical success include maximal incisal opening (MIO), pain relief, and dietary and functional improvement.1 Diminished or unimproved lateral and protrusive jaw movement is a commonly accepted consequence of complete TMJ replacement.2 Lateral excursive and protrusive function should, however, be considered and reported as an important measure of success after alloplastic TMJ replacement. To achieve such success, surgeons must comprehensively plan the reconstruction and reattach the lateral pterygoid muscle's inferior head (LPM-IH) to the prosthetic TMJ to support normal functional occlusion and mandibular motion.

Endoscopic Trans-Lateral Molar Approach to Infratemporal Fossa Lesions.

BACKGROUND: To study the endoscopic trans-lateral molar (ETLM) approach to infratemporal fossa (ITF) lesions and analyze the advantages and disadvantages of this method. METHODS: Four cases of ITF lesions were analyzed retrospectively. The clinical features, diagnosis and treatments, the operative process, and clinical applications of this surgical approach were discussed. RESULTS: Postoperative pathologies were 2 pleomorphic adenomas, 1 schwannoma, and 1 inflammatory lesion. All patients had self-resolving cheek swelling and pharyngalgia in the short term, but 2 patients had numbness in the long term. There was no infection or bleeding in the postoperative period, and no difficulty in chewing after disease recovery. There was no tumor recurrence during the follow-up period. CONCLUSION: The ETLM approach is convenient, minimally invasive, and allows complete excision of benign ITF lesions, posterior to the lateral pterygoid muscle and mainly below the level of the hard palate. It is a simple and direct access to the ITF, but it is a narrow access because of the limitations of bones and soft tissues. Appropriate patient selection is mandatory for successful surgery.

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

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

Anatomical and Clinical Implications in Neocondyle Stability After a Condylectomy.

: A condylectomy of the mandibular condyle is considered to be the treatment of choice in most cases of condylar head hyperactivity. The aim of the procedure is to remove the growth center of the mandible which is responsible for the mandibular enlargement and asymmetry. This surgical procedure has an impact on the condyle shape and position, but the restoration of mandibular movement and a stable joint position (namely, the proper alignment of the newly shaped condylar head within the condyle fossa) should also be considered important surgical outcomes. In this article, the authors present their own experience in performing condylectomies with an arthroplasty procedure and a special forced suturing technique (FST) in terms of achieving early, accurate mandibular movement and maintaining a stable condyle position in early and late outcomes. MATERIALS AND METHODS: A modified high condylectomy with arthroplasty and FST results had been studied in anatomical, radiological, and clinical model. RESULTS: Early findings after FST are promising. A slight improvement in lateral jaw movement was noted after condylectomy with arthroplasty (P < 0.05) both in early and late follow-up. Incisal opening, mandibular protrusion, and lateral movement were sustained. A stable condyle position within the fossa was achieved in each case of condylectomy with arthroplasty (P < 0.05). CONCLUSIONS: The FST condylectomy and reattachment of the lateral pterygoid muscle in a new, wider position provided an improvement in lateral jaw movement as well as in incisal opening and mandibular protrusion in early follow-up examination compared to the presurgical values. It seems that the FST enabled a better new condylar head position in the glenoid fossa and improved early functional mandibular movement.

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

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

Single versus double suspension sutures for selected cases of obstructive sleep apnea.

OBJECTIVE: To compare the results of expansion pharyngoplasty using bilateral single palatal suspension sutures (SSS) versus double suspension sutures (DSS) for the treatment of selected cases of obstructive sleep apnea (OSA) with retropalatal collapse. METHODS: Patients were randomly categorized into two groups: the first group for whom bilateral SSS were performed and a second group for whom bilateral DSS were done. Snoring on the basis of the visual analog scale (VAS), Epworth Sleepiness Scale (ESS), apnea hypopnea index (AHI), lowest O2 saturation were assessed preoperatively and 6 months postoperatively in all patients. RESULTS: DSS provided significantly more retroplatal space (p = 0.0137) and less snoring score (p = 0.0005). While no significance difference between SSS and DSS as regard inter pillar distance (p = 0.0985), AHI (p = 0.1677), ESS (p = 0.4094), and lowest O2 saturation (p = 0.0839). CONCLUSION: Both SSS and DSS are simple, rapid, bloodless and effective procedures for treating OSA (in patients with retropalatal collapse) with no temporary or persistent postoperative complications. Adding the second suture in DSS could significantly enlarge more retropalatal space and reduce more snoring scale than SSS.

Imaging-Ambiguous Lesions of Meckel's Cave-Utility of Endoscopic Endonasal Transpterygoid Biopsy.

INTRODUCTION: Meckel's cave is a dural-lined cavity in the middle fossa skull base in which lies the Gasserian ganglion, a potential site for tumors and inflammatory lesions. A variety of lesions can be predominantly isolated to Meckel's cave, including extension from head and neck cancers, other malignant tumors, as well as benign lesions. Clinical presentation and imaging findings are often insufficient to establish a diagnosis. Hence, histologic confirmation is required to determine the appropriate treatment strategy. Several surgical approaches have been used to reach this deep-seated area, often with significant morbidity and prolonged recovery. Given advancements in endoscopy and greater facility with the technique, the endoscopic endonasal approach has been used increasingly to reach lesions in the region. METHODS: A single-institution, retrospective chart review over a 10-year period was performed to identify and describe patients with pathologically differing but imaging-similar lesions with their epicenter in Meckel's cave. RESULTS: Of a total of 21 cases of lesions in Meckel's cave approached by an endoscopic endonasal transpterygoid approach, we present 6 patients with imaging-ambiguous lesions involving Meckel's cave that were biopsied via the extended endoscopic endonasal approach. Among this diverse group, pathology included B-cell lymphoma, squamous cell carcinoma, adenocarcinoma, malignant schwannoma, benign schwannoma, and neurosarcoidosis. CONCLUSIONS: We explore not only the relevance of this approach in the armamentarium of the modern skull-base surgeon but also its limitations and conclude that the endoscopic endonasal approach provides a safe and relatively direct, minimally invasive corridor to many lesions of Meckel's cave.

Surgical Management of Sphenoid Sinus Lateral Recess Cerebrospinal Fluid Leaks: A Single Neurosurgical Center Analysis of Endoscopic Endonasal Minimal Transpterygoid Approach.

OBJECTIVE: To review the results of sphenoid sinus lateral recess (SSLR) cerebrospinal fluid (CSF) leaks treated with the endoscopic endonasal minimal transpterygoid approach (EEMTPA) and to discuss the surgical technique and outcomes. METHODS: We performed a retrospective analysis of 13 cases who underwent SSLR CSF leak repair through the EEMTPA in our clinic between September 2008 and December 2017. Demographic and etiological features with reconstruction and surgical outcomes were examined. Mean follow-up time was 6.1 years. RESULTS: In regard to etiology, the SSLR CSF leaks included 9 patients with spontaneous, 2 patients with traumatic, and 2 with iatrogenic causes. CSF leak was at the left lateral recess in 8 cases and at right lateral recess in 5 cases. Nine patients had empty sella syndrome, and 11 patients had meningoencephaloceles in addition to SSLR CSF leaks. All patients underwent surgery through the EEMTPA, and a multilayer closure with tissue overlay grafts were used for reconstruction. A pedicled nasoseptal flap and/or pedicled middle turbinate flap were applied to the area of the leak in all cases. One patient had a persistent CSF leak and another had recurrence, both of which required revision surgery. Our overall success rate was 100%. CONCLUSIONS: EEMTPA is a safe and effective method that can be used to treat challenging pathologies at the SSLR, including CSF leaks accompanying meningoencephaloceles. Furthermore, the success rate of EEMTPA for SSLR CSF leaks can be increased by applying endoscopic skull base reconstruction techniques such as the pedicled nasoseptal flap and pedicled middle turbinate flap.

Endoscopic transpterygoid approach to a mass in a child.

The endoscopic transterygoid approach to the petrous apex is a feasible/alternative approach in carefully selected patients with specific favorable anatomy, even children. This approach, unlike traditional approaches, spares cochlear and vestibular function. We report a case of a six-year-old boy with embryonal rhabdomyosarcoma of the petrous apex that was diagnosed via the endoscopic transpterygoid approach.

Diffusion tensor imaging reveals morphological alterations of the lateral pterygoid muscle in patients with mandibular asymmetry.

OBJECTIVES: To evaluate non-invasively the morphological features of both lateral pterygoid muscle (LPM) and masseter muscle by using diffusion tensor Imaging on two patients affected by mandibular asymmetry. METHODS: Two female patients with mandibular excess and asymmetry who underwent Le Fort I osteotomy and bilateral sagittal split osteotomy were recruited for this study. Morphological (T1 weighted) and diffusion weighted images were acquired with a 3T scanner 1 week before (T0) and 1 month after the surgery (T1). Probabilistic tensor-based tractography reconstruction of bilateral masseters and LPMs was performed and mean fractional anisotropy (FA) values for both muscles were extracted. RESULTS: Diffusion tensor imaging was able to identify the muscle geometrical morphology and diffusion microstructural changes. Both at T0 and T1, mean FA values had no significant differences between the right and left side of masseter (at T0: p = 0.91; at T1: p = 0.54) and LPM (at T0: p = 0.92; at T1: p = 0.43), respectively. Both patients reported a significant improvement in FA mean values of the left LPM (p = 0.03) between T0 and T1, whereas no diffusion parameters' changes were observed for the bilateral masseter muscles and right LPM. CONCLUSIONS: We found that after the surgery the LPM ipsilateral to the deviation side showed a significant increase of FA compared to the baseline. Although preliminary, our findings suggest that diffusion tensor imaging may represent a promising tool to investigate non-invasively the masticatory muscles in temporomandibular joint disorders.