Deep Temporal Nerves Research Articles

Anatomical Bases of the Temporal Muscle Trigger Points.

Temporal muscles of 14 adult cadavers were studied. The muscle bellies were divided into six areas, three superior (1.2 and 3) and three inferior areas (4, 5, and 6) lower, according to a Cartesian plane to analyze and describe the entry points of the branches of the deep temporal nerves into the muscle. The branching distribution was analyzed using Poisson log-linear tests with Bonferroni post hoc tests for comparison between groups (sextants) (p < 0.05). Deep temporal nerve entry points were found in the temporal muscle in all areas. Most of the branches were observed in areas 2 and 5, which coincide with the muscle fibers responsible for mandible elevation and related to the previously described MTPs. Fewer branches were found in areas 1 and 6, where contraction produces mandible retraction. There is an anatomical correlation between the branching pattern of the deep temporal nerve and temporal muscle trigger points. Adequate knowledge of the innervation of the temporal muscle may help elucidate the pathophysiology of myofascial syndromes and provide a rational basis for interventional or conservative approaches and help surgeons avoid iatrogenic lesions to the deep temporal nerve lesion.

The surgical anatomy of the deep temporal nerve: A cadaveric study

The aims of this study were to investigate the surgical anatomy of the deep temporal nerve (DTN) and find (fixed/static) anatomical landmarks that could be used during surgery to localise the DTN branches. Ten hemifaces of Dutch cadavers were dissected at the Department of Anatomy of the Radboudumc. Landmarks and measurements of interest were number of branches of the DTN, distance from the tragus to the DTN, and distance from the cranial and caudal parts of the posterior root of the zygomatic bone until the DTN. In this cadaveric study, 10 hemifaces were dissected (male, n=6 [60%]; female, n=4 [40%]) with an equal left/right side division. The number of deep temporal branches varied from 2 (30%) to 3 (70%) per side. The mean distance to the tragus varied from 40 to 53mm, with a mean distance of 44.3±4.4mm. The mean distance from the cranial part of the posterior root of the zygomatic bone to the DTN varied from 29 to 35mm, with a mean distance of 31.3±2.1mm. The distance from the caudal part of the posterior root of the zygomatic bone to the DTN varied from 8 to 17mm, with a mean distance of 13.4±3.4mm. This study investigated the surgical anatomy and landmarks used for identification of the DTN and its branches. It suggested using firm landmarks for nerve identification, such as the posterior root of the cranial and/or the caudal zygomatic bone.

Endonasal access to the lateral poststyloid space: Far lateral extension of an endoscopic endonasal corridor

The styloid process constitutes the posterolateral boundary for an endonasal exposure of the infratemporal fossa. This study aims to explore the feasibility of a far‐lateral extension to the lateral poststyloid space via an endonasal corridor. An endonasal dissection was performed on six cadaveric specimens (12 sides). Following an endoscopic endonasal access to the parapharyngeal space, the styloid process and the tympanic portion of the temporal bone were removed to reveal the jugular bulb and the extratemporal facial nerve. Distances from the anterior nasal spine to the relevant landmarks were measured using a surgical navigation device. Through an endonasal corridor, only the anteroinferior aspect of the jugular bulb was exposed. Conversely, the extratemporal facial nerve could be sufficiently exposed, and the deep temporal nerve could be transposed to the stylomastoid foramen. The average horizontal distances from the nasal spine to the posterior tract of V3, styloid process, and facial nerve were 79.33 ± 3.41, 97.10 ± 4.74, and 104.77 ± 4.42 mm, respectively. Access to the lateral poststyloid space via an endonasal corridor is feasible, potentially providing an alternative approach to address select lesions extending to this region. The deep temporal nerve has a similar diameter to that of the facial nerve; thus, providing potential reinnervation of the facial nerve.

Salvage Procedures for Facial Reanimation With Neurovascular Flaps When Previous Surgeries Failed: Is Homolateral Vessel or Nerve Depletion a Contraindication?

Facial paralysis reconstruction can be difficult in extensive defects after complex facial or cranial base tumor resection and radiotherapy or when primary smile reanimation attempt has failed. The surgical challenge is more complicated when defects are associated with recipient vessels or nerves depletion. This scenario has not been well described in the literature, and the present article will address the alternatives that plastic surgeons may use in these circumstances. Seventy-five patients operated in the Hospital Gregorio Marañon between 2008 and 2020, for dynamic reconstruction of facial paralysis, were retrospectively evaluated, collecting data about previous facial nerve surgeries, radiotherapy, chemotherapy, recipient nerve for motor restoration and vessels used for free flaps, type of neurovascular free flap (NVFF), and functional score before and after the facial reanimation surgery. Patients presenting recipient vessel and/or nerve depletion after several facial surgeries requiring a variation from the common NVFF surgical protocol were included in this study. Six cases (8%) with facial paralysis and absent recipient homolateral vessels or nerves after severe cranial base surgery, parotid malignancies, or schwannoma surgery were included. Two patients had an immediate functional reconstruction during the oncologic resection surgery, and 4 patients had a delayed reconstruction. Three patients had previous reconstruction with free flaps, and the vascular pedicles of previous flaps were used for the new NVFF. In the other 3 cases, interposition vein grafts to the contralateral recipient vessels were required to perform NVFF. Masseteric nerve in 4 cases, hypoglossal nerve and posterior branch of the deep temporal nerve in 1 case each, were used as recipient nerves. House-Brackmann score improved in all patients after surgery. Neurovascular free flap can be successfully performed to restore facial motion after depletion of homolateral recipient vessels or nerves after previous facial or cranial base surgeries. In these cases, interposition vascular grafts or the pedicle of previous flaps are essential to provide vascularization as well as an optimal orientation of flaps, to reach recipient nerves in a 1-step procedure.

Temporomandibular joint innervation: Anatomical study and clinical implications

BackgroundTemporomandibular disorders and related pain are commonly seen in clinical practice. Due to its recurrent nature, they adversely affect a patient’s social life. Current knowledge on the temporomandibular joint (TMJ) innervation is debatable and insufficient to ensure optimal treatment for the underlying pathology. This study aimed to elucidate the pathophysiology of temporomandibular pain by revealing the TMJ innervation topography, its variations, and its relationships with the surrounding anatomical structures. This will aid in creating a guide for temporomandibular, infratemporal, and preauricular interventions. MethodsA total of 20 cadaver half heads, 10 fresh frozen and 10 embalmed, were used. The TMJ nerves were dissected together with the surrounding anatomical structures. ResultsWe showed that the TMJ is mainly innervated by the auriculotemporal nerve posteriorly, the masseteric nerve anteriorly, the posterior deep temporal nerve anteromedially, and the TMJ branch originating directly from the mandibular nerve medially, and that there are variations in these innervation pathways. Additionally, we emphasized how these nerves might be affected in certain clinical conditions based on their anatomical relationships and pathophysiological mechanisms. To our knowledge, this is the first study showing the existence of a branch of the mandibular nerve directly innervating the TMJ. ConclusionIn light of our findings, elucidating TMJ pain based on the anatomical characteristics of the region will allow precise treatment algorithms and better clinical outcomes in these patients. Based on this study, new clinical studies and interventions can be designed to reduce healthcare costs and alleviate the burden of temporomandibular disorders.

Transfer of the deep temporal nerve for eyelid reconstruction in Mobius syndrome – an anatomic feasibility study and proposed surgical approach

Facial paralysis may result in significant functional, esthetic, and psychological morbidity. Mobius syndrome is a form of bilateral congenital facial paralysis that is particularly difficult to treat owing to the lack of readily available donor nerves, particularly in the upper face. In this study, we evaluate the feasibility of using the deep temporal nerves as donors for the innervation of free muscle grafts in the periorbital region. Preserved and fresh cadaver facial halves are dissected, and the course of the deep temporal nerves delineated. We find the middle branch of the deep temporal nerve to be located consistently 4.6 cm from the posterior edge of the tragus along the zygomatic arch, giving an easily identifiable surface landmark for our donor. Finally, we outline a proposed surgical approach for using the middle deep temporal nerve to innervate a free muscle graft to the eyelids through an interpositional nerve graft.

Anatomical Variations and Relationships of the Infratemporal Fossa: Foundation of a Novel Endonasal Approach to the Foramen Ovale.

Objective Access to the infratemporal fossa (ITF) is complicated by its complex neurovascular relationships. In addition, copious bleeding from the pterygoid plexus adds to surgical challenge. This study aims to detail the anatomical relationships among the internal maxillary artery (IMA), pterygoid plexus, V 3, and pterygoid muscles in ITF. Furthermore, it introduces a novel approach that displaces the lateral pterygoid plate (LPP) to access the foramen ovale. Design and Main Outcome Measures Six cadaveric specimens (12 sides) were dissected using an endonasal approach to the ITF modified by releasing and displacing the LPP and lateral pterygoid muscle (LPTM) as a unit. Subperiosteal elevation of the superior head of LPTM revealed the foramen ovale. The anatomic relationships among the V 3 , pterygoid muscles, pterygoid plexus, and IMA were surveyed. Results In 9/12 sides (75%), the proximal IMA ran between the temporalis and the LPTM, whereas in 3/12 sides (25%), the IMA pierced the LPTM. The deep temporal nerve was a consistent landmark to separate the superior and inferior heads of LPTM. An endonasal approach displacing the LPP in combination with a subperiosteal elevation of the superior head of LPTM provided access to the posterior trunk of V 3 and foramen ovale while sparing injury of the LPTM and exposing the pterygoid plexus. The anterior trunk of V 3 traveled anterolaterally along the greater wing of sphenoid in all specimens. Conclusion Displacement of the LPP and LPTM provided direct exposure of foramen ovale and V 3 avoiding dissection of the muscle and pterygoid plexus; thus, this maneuver may prevent intraoperative bleeding and postoperative trismus.

Twin Block in Myogenous Orofacial Pain: Applied Anatomy, Technique Update, and Safety.

The twin block, introduced in 2014, has proven to be more advantageous for the management of myogenous orofacial pain than the masseteric nerve block, which was introduced in 2009. The twin block is an extraoral nerve block injection which passes through the temporal fossa to anesthetize both the masseteric and the deep temporal nerves as they exit the infratemporal fossa at the infratemporal crest. Similar to the masseteric nerve block, the twin block has demonstrated efficacy with expeditious and sustained relief of myogenous face pain originating from the masseter muscle. Furthermore, in a 6-month prospective treatment study, that has been accepted for publication, the twin block has been demonstrated as comparable to trigger point injections in the management of chronic myofascial pain of masseteric origin. The twin block's ability to mitigate myogenous pain from both the masseter and temporalis muscles and its ease of administration are the key advantages over the masseteric nerve block. Since its inception, we have refined the technique for administering the twin block and our clinical experience corroborates its safety and efficacy. This review describes the refined technique and its safety in the context of the region's applied anatomy.

Five-Year Experience with Fifth-to-Seventh Nerve Transfer for Smile.

Masseteric- or deep temporal-to-facial nerve transfer (five-to-seven nerve transfer) is increasingly used in facial reanimation; however, the indications and clinical variables affecting outcomes for five-to-seven nerve transfer have not been defined. The authors describe their early experience with five-to-seven nerve transfer, reporting function and patient-reported outcomes, to identify potential parameters that are predictive of outcome. The authors conducted a retrospective chart review of all patients who underwent five-to-seven nerve transfer for smile reanimation from 2012 to 2017. Age, sex, cause of facial paralysis, onset and duration of paralysis, history of adjuvant chemotherapy and/or radiation therapy, donor nerve used, adjunctive procedures, and final excursion were recorded. Standard photographs and videos, and data regarding clinical facial nerve function and patient-reported quality of life, were obtained preoperatively and postoperatively. Sixty patients were identified. Forty-seven had flaccid facial paralysis and 13 had postparalysis facial palsy. Among flaccid facial paralysis patients, masseteric nerve transfer was successful in 30 patients (88 percent) and deep temporal nerve transfer was successful in three cases (60 percent). Among postparalysis facial palsy patients, five-to-seven nerve transfer was successful in two patients (20 percent). Average quality-of-life scores improved significantly from preoperatively (46) to postoperatively (59) among flaccid facial paralysis patients with successful five-to-seven nerve transfer. Five-to-seven nerve transfer is a viable option in facial reanimation. Shorter denervation times and preoperative flaccidity are favorable predictors of outcome. Five-to-seven nerve transfer as an adjunct to primary repair appears highly effective for enhancing smile function. Five-to-seven nerve transfer results are not reliable in patients with postparalysis facial palsy. Therapeutic, IV.

Temporomandibular joint arthrocentesis: a technique proposal. Case report

ABSTRACT BACKGROUND AND OBJECTIVES: Arthrocentesis is an effective treatment to reduce or eliminate pain, increase maximal interincisal distance, and to eliminate joint effusion in patients with disc displacement without reduction. This study aims to expose and to discuss a new technique proposal of temporomandibular joint arthrocentesis applied in the treatment of a single case of disc displacement without reduction. CASE REPORT: Female patient, 18-year-old patient sought treatment due to joint pain and mouth opening limitation. The maximal interincisal distance was 30.28mm. Magnetic resonance imaging confirmed the diagnosis of disc displacement without reduction with signs of joint effusion in the right temporomandibular joint. Temporomandibular joint arthrocentesis was performed under selective sensory nerve block of the auriculotemporal, the masseteric and posterior deep temporal nerves. Two needles were inserted in the upper compartment of the temporomandibular joint. In the second needle, a transparent catheter was connected into a vacuum pump. Clinically, after the arthrocentesis, the maximal interincisal distance increased to 46.25mm, and the patient referred no more pain. After six months, a magnetic resonance imaging was performed to observe the results, and there were no more signs of joint effusion. CONCLUSION: Temporomandibular joint arthrocentesis was an effective treatment for this patient with disc displacement without reduction. The aspect of this technique that is particularly relevant for clinical practice was the connection of a transparent catheter to a vacuum pump. In fact, it allowed the visualization of the solution fluidity, as well as guides the flow of the solution used for joint washing, optimizing the irrigation. However, new studies are necessary to compare different protocols of irrigation with and without the associated use of a vacuum pump.

Efficacy of the twin block, a peripheral nerve block for the management of chronic masticatory myofascial pain: A case series.

Masticatory myofascial pain is the one of the most common etiologies for nonodontogenic pain, often characterized by the presence of trigger points. Conventional management includes approaches such as jaw exercises, physical therapy, intraoral appliances, medications, and trigger point injections. Peripheral/regional nerve blocks have shown to be effective in managing myogenous pain conditions. The twin block is a nerve block that blocks both the masseteric and the anterior deep temporal nerves. The objective of this case series is to illustrate expeditious and sustained efficacy of the twin block in the management of chronic masticatory myofascial pain.

L’innervation motrice de la face. Anatomie chirurgicale et radiologique des paralysies faciales et de leur réparation chirurgicale

Motor innervation of the face depends on the facial nerve for the mobility of the face, on the mandibular nerve, third branch of the trigeminal nerve, which gives the motor innervation of the masticator muscles, and the hypoglossal nerve for the tongue. In case of facial paralysis, the most common palliative surgical techniques are the lengthening temporalis myoplasty (the temporal is innervated by the mandibular nerve) and the hypoglossal-facial anastomosis. The aim of this work is to describe the surgical anatomy of these three nerves and the radiologic anatomy of the facial nerve inside the temporal bone. Then the facial nerve penetrates inside the parotid gland giving a plexus. Four branches of the facial nerve leave the parotid gland: they are called temporal, zygomatic, buccal and marginal which give innervation to the cutaneous muscles of the face. Mandibular nerve gives three branches to the temporal muscles: the anterior, intermediate and posterior deep temporal nerves which penetrate inside the deep aspect of the temporal muscle in front of the infratemporal line. The hypoglossal nerve is only the motor nerve to the tongue. The ansa cervicalis, which is coming from the superficial cervical plexus and joins the hypoglossal nerve in the submandibular area is giving the motor innervation to subhyoid muscles and to the geniohyoid muscle.

Identification of the posterior deep temporal nerve groove and canal, and its relationship to basicranial angle

The posterior deep temporal nerve (PDTN) groove accommodates the posterior deep temporal nerve and is infrequently described. This area is important for some clinical procedures including mandibular nerve blockade. This study assesses the prevalence and morphological variations of the PDTN groove in a single population, investigating its relationship with basicranial angle to assess predictive value for the existence of this feature. The infratemporal regions of 101 contemporary Sinhalese Sri Lankan skulls were examined bilaterally and ordinally scored for PDTN groove morphology (six point scale); 11 random skulls were radiographed and basicranial angles measured. Descriptive statistics and significance testing (P < 0.05) were used for analysis, including symmetry (Wilcoxon matched-pairs signed rank test), sex differences (Mann and Whitney U test), and between basicranial angle and PDTN morphology (Pearson's product-moment correlation coefficient). Ninety skulls (44 males) were included for analysis (180 sides). PDTN groove morphology on individual sides ranged from non-existent (20.6%) to partial (5.6%) and complete canals (1.1%); 93.3% of skulls had a PDTN groove or canal. Skulls exhibited bilateral symmetry (P = 0.12) and males had significantly deeper PDTN grooves or canals (P = 0.018). Basicranial flexion correlated strongly with PDTN groove or canal prevalence (P = 0.0028). Sri Lankan skulls have a high prevalence of PDTN grooves and also canals, a feature not previously described. Prevalence was related significantly to sex but not symmetry, and PDTN grooves and canals correlated significantly with basicranial angle. Knowledge of this morphology is important for some clinical procedures, anthropological assessment, and as a location for PDTN entrapment.

The twin block: a simple technique to block both the masseteric and the anterior deep temporal nerves with one anesthetic injection

The objective of this article is to describe a new technique to anesthetize the masseter muscle and the temporalis muscle using a single extraoral approach. The block targets both the masseteric and the deep temporal nerves as they leave the infratemporal fossa to innervate the deep surfaces of their respective muscles.

Evidence for the Functional Compartmentalization of the Temporalis Muscle: A 3-Dimensional Study of Innervation

The temporalis muscle is commonly used for functional transfer. It is architecturally complex, but few studies have examined its intramuscular innervation and none has used 3-dimensional modeling techniques. Understanding neuromuscular compartmentalization may allow the design of local muscle transfers to minimize donor-site morbidity. The purpose of the present study was to document the intramuscular innervation patterns throughout the volume of the temporalis muscle and define functional units within the muscle. In 10 formalin-embalmed cadaveric specimens, the foramen ovale was exposed and the branches of the mandibular nerve were identified. Each branch was digitized in short segments extramuscularly and intramuscularly. Three-dimensional models were reconstructed from the digitized data using Maya software, and the innervation patterns were documented. The temporalis muscle was found to have superior and inferior parts that were further grouped by innervation into regions, with each receiving its innervation from 1 primary nerve. The nerves originated directly from the mandibular nerve, except in 3 specimens, where the posterior deep temporal nerve arose from the masseteric nerve. These results provide a detailed mapping of innervation patterns and suggest there are at least 5 functional compartments. Each of these has the capacity for selective activation, 3 of which have clinical value. These findings may allow for decreased donor-site morbidity and more functionally sophisticated designs in clinical practice.

Fetal developmental change in topographical relationship between the human lateral pterygoid muscle and buccal nerve

In adults, the lateral pterygoid muscle (LPM) is usually divided into the upper and lower heads, between which the buccal nerve passes. Using sagittal or horizontal sections of 14 fetuses and seven embryos (five specimens at approximately 20-25 weeks; five at 14-16 weeks; four at 8 weeks; seven at 6-7 weeks), we examined the topographical relationship between the LPM and the buccal nerve. In large fetuses later than 15 weeks, the upper head of the LPM was clearly discriminated from the lower head. However, the upper head was much smaller than the lower head in the smaller fetuses. Thus, in the latter, the upper head was better described as an 'anterior slip' extending from the lower head or the major muscle mass to the anterior side of the buccal nerve. The postero-anterior nerve course seemed to be determined by a branch to the temporalis muscle (i.e. the anterior deep temporal nerve). At 8 weeks, the buccal nerve passed through the roof of the small, fan-like LPM. At 6-7 weeks, the LPM anlage was embedded between the temporobuccal nerve trunk and the inferior alveolar nerve. Therefore, parts of the LPM were likely to 'leak' out of slits between the origins of the mandibular nerve branches at 7-8 weeks, and seemed to grow in size during weeks 14-20 and extend anterosuperiorly along the infratemporal surface of the prominently developing greater wing of the sphenoid bone. Consequently, the topographical relationship between the LPM and the buccal nerve appeared to 'change' during fetal development due to delayed development of the upper head.

Anatomy of the infratemporal crest: Implications for cross-facial nerve grafting in temporal myoplasty

Temporalis transfers for reanimation in facial palsy have been criticised for the lack of neural input from a functioning facial nerve. Cross-facial nerve grafting to the deep temporal nerves may provide a solution. An anatomical study was performed to further elucidate the deep temporal nerves (DTN) and arteries, examining anatomical variation and infratemporal distribution. Seventeen temporalis muscles were dissected from 13 cadavers as part of a BSc project. The number, branching pattern, length and diameter of DTN were recorded. Arteries supplying the deep surface of temporalis and their relation to DTN were noted. Six specimens were processed using Sihler's staining technique. Arteries were injected with Iodixanol X-ray contrast medium and radiographs taken. All specimens displayed a single DTN originating from the anterior branch of V(3). A mean of 3 branches was observed. The nerve length was 14.22±3.95 mm. The point of entry of DTN into temporalis showed great consistency. Upon exiting the infratemporal fossa, the posterior deep temporal artery was deep and posterior to DTN in 65% of specimens. The branching pattern of DTN can be classified into three types. The deep arterial supply to temporalis was constant in all specimens. This study provides an anatomical basis for the planning and execution of cross-facial nerve grafting to temporalis, and for protection of vital structures. Furthermore, it helps to clarify inconsistencies in the literature regarding nomenclature of the nerve branching pattern of the deep temporal nerves.

Temporalis muscle innervation patterns are generally conserved across subjects

The temporalis muscle is structurally complex; its muscular architecture is often misrepresented and its innervation pattern is not well characterized. In this study we digitized and mapped the 3D extramuscular and intramuscular mandibular nerve course from foramen ovale to its terminal branches in the temporalis muscle belly in four formalin embalmed cadaveric specimens. The muscle mass was dissected and digitized in layers to map its volume. The digitized nerve and muscle volume data were reconstructed into a 3D model using Maya® for visualization. Lateral 2D views were then manually registered to a common geometrical template using linear and non‐linear transformation techniques in Adobe Photoshop CS5. The extramuscular innervation consisted of three deep temporal nerves corresponding to anterior, middle and posterior portions of the muscle, masseteric and buccal nerves. Intramuscularly, the extent of muscle mass innervated by each of the nerves differed depending on the number of terminal branches. The spatial distribution of registered nerve branches was generally conserved suggesting that the degree of terminal branching was indicative of neurogenic control. We noted abundant intramuscular nerve fiber anastomosis from the anterior to posterior extent of the muscle in individuals. This work was supported by the American Association of Anatomists Visiting Scholarship.

Use of Masseteric and Deep Temporal Nerve Blocks for Reduction of Mandibular Dislocation

A patient presented with a unilateral dislocated condyle that was resistant to reduction by simple manual manipulation because of elevator muscle spasm and severe muscle and temporomandibular joint pain. A technique involving a masseteric nerve block and a temporal nerve block was used, allowing a quick, safe, and minimally painful reduction. The method used for delivering these nerve blocks is described here.

Masticatory muscles of the great‐gray kangaroo (Macropus giganteus)

The great-gray kangaroo (Macropus giganteus) belongs to the Diprotodontia suborder (herbivorous marsupials of Australia) of the order of marsupials. We dissected the masticatory muscles in the great-gray kangaroo and classified them based on their innervation. Three (two male and one female) adult great-gray kangaroos (M. giganteus), fixed with 10% formalin, were examined. The masseter muscle of the great-gray kangaroo was classified into four layers (superficial layers 1, 2, 3, and a deep layer), all innervated by masseteric nerves. Layer 1 of the masseter muscle was well developed and the deep layer inserted into the masseteric canal. The zygomaticomandibular muscle, which belongs to both the masseter and temporalis muscles, was innervated by both the masseteric nerve and posterior deep temporal nerve, and the temporalis muscle was innervated by the anterior and posterior deep temporal nerves. The medial pterygoid muscle, which was innervated by the medial pterygoid nerve, was divided into superficial and deep portions. The lateral pterygoid muscle was divided into superior and inferior heads by the buccal nerve. We propose that the relationship of the masticatory muscles in the kangaroo has evolved by passive anterior invasion of the deep layer of the masseter by the medial pterygoid muscle via the masseteric canal, associated with the development of an anteroposterior mode of mastication.