Mandibular Division Of Trigeminal Nerve Research Articles

453 Changed Innervation Upon Loss of Mandibular Division of Trigeminal Nerve to Muscles of Mastication

INTRODUCTION: The gastrulation brain homeobox (Gbx) genes are essential for patterning and maintenance of neurons along the anteroposterior axis of the developing neural tube. Knockout (ko) of Gbx2 results in neonatal lethality associated with neurological and other defects. To understand pathologies, ko studies are not realistic as gene loss usually results in death before birth. Gbx2 neo/neo mutant mice express 6-10% of the wildtype Gbx2 expression levels. They have milder malformations than ko mice but lack the cerebellar vermis and mandibular division of the trigeminal nerve (3rd division of 5th cranial nerve = V3), among other defects. These Gbx2 neo/neo mutant mice die perinatally as they are unable to suckle due to lack of motor innervation via V3 to the muscles of mastication. Muscle cells develop largely without interaction with their motor nerve. However, the final differentiation of myocytes requires interactions with nerve fibers. Unexpectedly, the muscles of mastication appear normal in Gbx2 neo/neo mutant mice, despite the lack of V3. METHODS: We performed microdissections of neonate wildtype and Gbx2neo/neo mutant mice. Additionally, we embedded mutant and wildtype mouse embryos in paraffin, serial sectioned them (7 μm), stained the sections with Azan staining, and analyzed specimen microscopically. RESULTS: Current analysis of the data to identify where nerve fibers in the muscles of mastication originate is in process. We favor the origin of these fibers from the facial nerve (7th cranial nerve), which has several overlapping territories with the trigeminal nerve. CONCLUSIONS: Muscles require innervation for their final differentiation steps. The loss of a nerve can result in the invasion of another nerve into the territory of the lost one, which rescues muscle differentiation but not muscle function. IACUC Ziermann Med-20-02, Funding NSF #2000005 to Ziermann.

Expect the Unexpected!! – Transient Cranial Nerve Palsies after Radiofrequency Ablation of Gasserian Ganglion for Trigeminal Neuralgia

Trigeminal neuralgia is the most common type of craniofacial neuralgia, characterized by paroxysmal lancinating electric shock-like pain confined to the somatosensory distribution of the trigeminal nerve. Fluoroscopy-guided Radiofrequency Ablation of Gasserian Ganglion (RFA-GG) is the commonly performed minimally invasive pain intervention in these patients. Various complications such as masseter weakness, corneal anesthesia, dysesthesia, anesthesia dolorosa, keratitis, and cranial nerve deficits have been reported during the procedure. We present the case of a 58-year-old male diagnosed with left-sided trigeminal neuralgia involving mandibular division of trigeminal nerve (V3 division) with a Numerical Rating Scale of 9/10 at the time of presentation. As the patient was unresponsive to medical management, RFA of the V3 division of GG was performed with acceptable sensory and motor stimulation. Postablation, 1 ml of 1.0% Lidocaine injection with 2 mg injection dexamethasone was given. After the procedure, the patient complained of dizziness, left-sided hearing loss, and double vision on looking toward the left side. On examination, deviation of the angle of the mouth toward the right side, reduced blink reflex on the left side, and incomplete closure of the left eyelid were observed. Vitals were stable and there was no respiratory discomfort. The patient was reassured and monitored in the recovery room. Signs and symptoms were transient and the patient recovered completely after 45 min. Clinical findings were suggestive of the involvement of three cranial nerves: the abducens nerve, the facial nerve, and the vestibulocochlear nerve. Spillage of local anesthetic solution into adjacent cranial nerves surrounding the GG might be the causative mechanism for transient cranial nerve palsies in this case.

LINGUAL NERVE IN RELATION TO MANDIBULAR THIRD MOLAR REGION: A CADAVERIC STUDY

Background: The lingual nerve is the terminal branch of the mandibular division of trigeminal nerve. The spatial relationship of lingual nerve to the mandibular alveolar crest varies widely. This variation can be among the gender, age, dental status and between the right and left side of the same sample. This study was aimed to determine the relationship of lingual nerve to mandibular third molar region. Methods: An observational study was carried out from January 2021 to December 2021.The study sample was 15 cadavers including both right and left sides. The lingual nerve was exposed by dissecting the infra temporal region following the standard procedures of Cunninghams Manual of Dissection. The diameter of the lingual nerve, vertical and horizontal distance were measured. The results of all these measurements were tabulated and mean standard deviation were calculated using SPSS version 16. Results: Out of 30 lingual nerves examined, the mean horizontal distance was 3.99 ± 0.96 mm, the mean vertical distance was 12.67 ± 1.76 mm while the diameter of the lingual nerve was 2.46 ± 0.54 mm. Conclusions: The lingual nerve always lies in close proximity of alveolar bone and surgeons operating in this region need to be aware during any surgical interventions or any procedures in this region. A thorough apprehension of the spatial location of the lingual nerve enable to lessen the lingual nerve injury.

A rare event of trigeminocardiac reflex during mandibular branch of trigeminal nerve radiofrequency ablation

We at Our Pain Clinic witnessed a rare event of recurrent bradycardia and hypotension during radiofrequency ablation of mandibular division of trigeminal nerve. A 48-year-old lady with trigeminal neuralgia in left V3 distribution was posted for V3 division rhizotomy under fluoroscopy. The patient had transient episodes of bradycardia and hypotension during the procedure. The patient had transient episodes of bradycardia and hypotension during the procedure. HR and BP were reverted to baseline with injection atropine and intravenous fluids. This response is most likely attributed to trigemino cardiac reflex, which occurs due to inadvertent stimulation of trigeminal nerve.

Trigeminal neuralgia as a presenting symptom of brain metastasis in advanced stage of breast cancer

Trigeminal neuralgia is defined as sudden, usually unilateral, severe, brief, stabbing, recurrent episodes of pain in the distribution of one or more branches of the trigeminal nerve. We report a case of trigeminal neuralgia which was a presenting symptom for the diagnosis of brain metatstasis in a patient with advanced stage of breast cancer. A 51 old female complained of right facial pain. She had been diagnosed invasive ductal carcinoma one year ago. Since the detection of cancer, she had multiple metastasis in bone, both lung and chest wall. Brief recurrent lanscinating right facial pain was persisted during 7 days without relief. On admission, pain was distributed in maxillary and mandibular division of trigeminal nerve. Neurologic examination revealed no contraction of masseter and temporalis on the same side. Hypestheia was accompanied in right maxillary and mandibular branch of trigeminal nerve. Brain MRI depicted multiple metastasis in right cavernous sinus, Meckel’s cave and bilateral cerebellum. Neurophysiologic study showed normal blink reflex response, but no potential for masseter reflex test. She was diagnosed with secondary trigeminal neuralgia and we prescribed oxcarbazepine with palliative chemotherapy. Malignant metastasis involving the path of trigeminal nerve could elicit neuralgic pain as a secondary cause of trigeminal neuralgia. In our patient, the neuralgic pain in the area of trigeminal nerve was the only presenting symptom of brain metastasis. Secondary cause of trigeminal neuralgia should be evaluated with extensive brain imaging especially in patient with cancer.

Comparison of efficacy of adriamycin chemo-ganglionectomy and radiofrequency thermocoagulation of gasserian ganglionin in treating craniofacial postherpetic neuralgia

Objective To compare the efficacy of adriamycin chemo-ganglionectomy and radiofrequency thermocoagulation (RFT) of semilunar ganglion in treating craniofacial postherpetic neuralgia (PHN). Methods A total of 95 patients with PHN in the areas innervated by maxillary and mandibular divisions of trigeminal nerve, aged 55-90 yr, with the course of disease 6 months-3 yr, were divided into 2 groups using a random number table method: adriamycin chemo-ganglionectomy group (ADM group, n=48) and RFT group (n=47). Hartel anterior approach to puncture was performed via the foramen ovale under the guidance of CT in two groups.In group ADM, 0.5% adriamycin 2.5 mg (0.5 ml) was injected via the foramen ovale, and RFT of gasserian ganglion was performed in group RFT.Visual Analog Scale (VAS) and the short-form McGill pain questionnaire (SF-MPQ) scores were evaluated before and after treatment.The rate of effective treatment was calculated, and treatment-related complications were recorded. Results Compared with group RFT, no significant change was found in VAS or SF-MPQ scores before treatment, VAS and SF-MPQ scores were increased and the rate of effective treatment was decreased at 1 and 7 days after treatment, VAS and SF-MPQ scores were decreased and the rate of effective treatment was increased at 6 and 12 months after treatment, the incidence of facial numbness, hypoesthesia, masticatory muscle weakness and weakened corneal reflex was decreased in group ADM (P<0.05). Conclusion Compared with semilunar ganglion RFT, the long-term efficacy of adriamycin chemo-ganglionectomy of semilunar ganglion in treating craniofacial PHN is enhanced, and the safety is higher. Key words: Neuralgia, postherpetic; Doxorubicin; Electrocoagulation; Trigeminal ganglion

Lingual Nerve Damage during Third Molar Extraction – A Review

Aim: The lingual nerve damage during the third molar extraction has been prevalent in all cases. Injury to the lingual nerve are serious complications that can arise rom the performance of a number of oral and maxillofacial surgeries. Background: The lingual nerve is a branch of the mandibular division of trigeminal nerve which supplies the sensory innervation to the tongue. Lingual nerve injury is a common complication following the dental procedures. The clinical presentation of lingual nerve injury, its epidemiology, predisposing factors, and anatomy are explored in an attempt to identify those patients at risk for developing pain. Reason: The alternative methods used to extract the tooth without causing any damage and coupling with anatomical, dental and proper classification will ultimately determine the potential for nerve injury. This review will bring about a clear idea of the actual cause of the lingual nerve damage.

Rare locations of schwannomas: a few comments.

Dear Editor; With curiosity I read the original article by Jeong et al. [1]. They proposed to modify the classification of trigeminal schwannomas (TSs) according to their extension into the adjacent compartment, shape, and location of origin, and concluded that TSs could be removed safely and effectively according to their modified classification. The authors are to be congratulated for conducting such a well-managed study on a topic of schwannomas. Here, I would like to add some additional points about the rare locations origin of schwannomas. Schwannomas may originate from any cranial, peripheral or autonomic nerve of the body and are uncommon nerve sheath tumors. About one-third of schwannomas are identified to arise in the neck and head region. TSs are known to arise from the ganglion, root, or intracranial portion of the peripheral divisions of the nerve-mandibular, maxillary, and ophthalmic. Schwannomas including the mandibular division of trigeminal nerve and localizing particularly in the parapharyngeal space is entirely rare. The most common nerves of origin of TSs in the parapharyngeal space are the sympathetic chain and the vagus nerve [2]. On the other hand, an exceedingly rare schwannomas is olfactory schwannoma as the olfactory nerve is unsheathed by schwann cells, till today, only 48 cases have been reported worldwide [3]. Also, there have been no persuasive theories that are comprehensively accepted to define the origin of olfactory schwannoma. Additionally, a rare bone tumor is intraosseous schwannomas which is accounting for less than 1%. Notably, mandible is the most common site of intraosseous schwannoma, however, intraosseous skull vault schwannomas are very rare [4]. As is obvious from above discussion, parapharyngeal, olfactory, and intraosseous spaces are extremely rare locations origin of schwannomas which the management of them is a clinical challenge. In this regard, more studies may need to focus on this area.

?Nevus of Ota?: A Rare Oro-Facial Pigmentation- Short Review

Nevus of Ota is a dermal melanocytic hamartoma of unknown cause and rare in Indian subcontinent, associated with ophthalmic, maxillary and mandibular divisions of trigeminal nerve. Oral involvement of nevus of ota is very rare and found mostly in females. This review highlights this obscure, but important oro-facial pigmentation.

Percutaneous Radiofrequency Rhizotomy in Treatment of Trigeminal neuralgia: A Prospective Study

Trigeminal neuralgia (TN) often called as "Tic douloureux" is a syndrome characterized by paroxysmal facial pain, is one of the most painful and debilitating craniofacial pain disorders. The controversy regarding the etiology and treatment of TN still exists. To evaluate the effectiveness of percutaneous radiofrequency rhizotomy (PRR) for TN, after failure of pharmacological management. A nonrandomized, non comparative, descriptive, in vivo study of 15 patients with TN of maxillary and mandibular divisions of trigeminal nerve and patients with pain refractory to pharmacological management were done. It was performed as an O.P.D procedure. A routine follow up was done in all cases for 1year. In a total of 15 patients, 8 female and 7 male patients were enrolled for the study. Early pain relief (immediately, postoperatively to 6month) classified as excellent or good (successful), occurred in 12 of 15 patients (80%). Fair or poor pain relief (unsuccessful) occurred in three patients (20%).There was no mortalities and no major morbidity. It was found that surgical treatment with PRR is a safe and effective way to manage patients with TN in whom pharmacologic therapy is either ineffective or not tolerated, with low side effects which are well tolerated.