What Is a Maxillary Nerve?

Maxillary nerve: The maxillary nerve is the second branch of the trigeminal nerve and is the sensory nerve. Starting from the half moon festival, the skull emerges from the round hole of the sphenoid bone. It can be divided into four sections: intracranial, pterygopalatine recess, intraorbital and face. The intracranial segment is divided into the meningeal nerve, the pterygopalatine fossa segment is divided into the sacroiliac nerve, the sphenopalatine nerve, and the superior alveolar nerve. , That is, the infraorbital nerve. Dominates the sensory function of the entire maxilla and ipsilateral nose, lower lip, lower eyelid, teeth, and soft and hard palate on the same side.

Maxillary nerve: The maxillary nerve is the second branch of the trigeminal nerve and is the sensory nerve. Starting from the half moon festival, the skull emerges from the round hole of the sphenoid bone. It can be divided into four sections: intracranial, pterygopalatine recess, intraorbital and face. The intracranial segment is divided into the meningeal nerve, the pterygopalatine fossa segment is divided into the sacroiliac nerve, the sphenopalatine nerve, and the superior alveolar nerve. , That is, the infraorbital nerve. Dominates the sensory function of the entire maxilla and ipsilateral nose, lower lip, lower eyelid, teeth, and soft and hard palate on the same side.

Chinese name

Maxillary nerve

Foreign name

maxillary nerve

Overview of the maxillary nerve

One of the branches of the trigeminal nerve of the maxillary nervous system. This nerve is distributed in the skin between the cleft lip and cleft palate, the teeth of the upper jaw, and the mucous membranes of the nasal cavity and mouth. After the maxillary nerve is sent from the semilunar segment of the trigeminal nerve, it passes through the cavernous sinus, passes through the circular hole to the pterygopalatine fossa, and extends into the suborbital nerve. Its branches are: phrenic nerve, sphenopalatine nerve, posterior alveolar branch. When the maxillary nerve is damaged, the distribution area is sensory.

Maxillary nerve Maxillary nerve morphological structure and its trend

The maxillary nerve is the sensory nerve. It starts at the midpoint of the semilunar segment and exits from the sphenoid round hole to the frontal cavernous sinus side. Through the infraorbital canal, from the infraorbital foramen to the face, the maxillary nerve is generally divided into four parts: intracranial, pterygopalatine recess, intraorbital, and face.

(1) Intracranial segment: The nerves in the meninges are separated and distributed in the cranium.

(2) Pterygopalatine fossa segment: Separate the phrenic nerve, sphenopalatine nerve, and posterior alveolar nerve. The phrenic nerve, from the pterygopalatine concavity, enters the orbit through the suborbital fissure, divides into the zygomatic surface and the temporal surface, and spreads through the sacrum to the zygomatic arch, zygomatic and temporal skin; Branches pass through the wing and concavity to chrysalis. The chrysalis is located in the pterygopalatine recess, near the pterygopalatine foramen, and has three roots: sensory, parasympathetic, and sympathetic. From this section several branches, such as the orbital branch, nasal branch, iliac branch, and pharyngeal branch. The orbital branch, from the suborbital fissure into the orbit, is distributed in the periosteum and lacrimal gland. Nasal branch, one is the posterior superior nasal branch. After entering the nasal cavity through the sphenopalatine hole, it is distributed in the nasal septum, upper middle turbinate mucosa, and ethmoid honeycomb intima. One is the nasal diaphragm nerve, which passes through the incisor tube forward and inferior to the incisor canal along the nasal septum. It is distributed in the maxillary incisors, canines, and anterior 1/3 of the periosteal mucosa and zygomatic lateral roots. The maxillary canine is connected to the anterior iliac nerve at the zygomatic side. The iliac branch is the phrenic nerve, which is divided into three branches: anterior, middle and posterior. Descent to tadpoles through the pterygopalm. The anterior iliac nerve passes through the pterygopalatine to exit the iliac foramen into the hard palate. It is distributed forward in the maxillary premolars, the periosteal mucosa, the zygomatic gingival, and the sacral glands, and anastomoses the nasal and sacral nerves in the iliac mucosa of the canine. , Synthesis of the upper alveolar plexus inner ring. The medial and posterior nerves pass through the pterygopalatine canal to form the foramen foramen, which are distributed in the uvula, tonsils and soft palate. The pharyngeal branch is the pharyngeal nerve, starting from the sphenopalatine, with the pharyngeal artery penetrating the pharyngeal duct and distributed in the nasal mucosa of the pharynx. The posterior alveolar nerve emerges from the pterygopalatine fossa to the back of the maxillary tubercle and issues the upper gingival branch, which is distributed on the mucosa and gums of the maxillary molars on the buccal side. It then enters the maxillary body through the maxillary alveolar hole, descends along the maxillary sinus wall, and is distributed on one maxillary molar (except the mesial root of the buccal side of the first molar), the periodontal membrane, the alveolar bone, and the outer wall of the maxilla. It is connected to the superior alveolar nerve at the buccal mesial root of the first molar.

(3) Inner orbital segment: the superior alveolar nerve and superior alveolar nerve are issued. The superior alveolar nerve is emitted in the posterior branch of the superior orbital canal, descending forward and outward on the lateral wall of the maxillary sinus, distributed on one side of the maxillary premolar, the maxillary first molar, the buccal mesial root, the periodontal membrane, and the buccal gum. The alveolar bone and maxillary sinus mucosa are connected to the anterior and posterior nerves of the upper alveolar and form the outer ring of the upper alveolar plexus. The anterior alveolar nerve is emitted in the infraorbital canal, and enters the alveolar along the anterior wall of the maxillary sinus. There is an anastomosis with the nerve in the upper alveolar at the canine.

(4) Facial segment: It is the terminal branch of the maxillary nerve, that is, the infraorbital nerve. It is divided into the eyelid branch, nasal branch, and lip branch after penetrating from the infraorbital foramen. The eyelid branch is distributed on the lower eyelid skin and cornea, the nasal branch is distributed on the nasal skin, and the lip branch is distributed on the upper lip skin and mucosa.

Maxillary nerve anesthesia

Indications

1. Surgery involving maxillary sinus, ambushed third molar, partial maxillary resection, maxillary fracture correction and maxillary deformity.

2. It is not advisable to perform infraorbital nerve block or infiltration anesthesia due to local inflammation.

3. Identify the second trigeminal neuralgia.

[Preparation before anesthesia]

1. Disinfect the skin in the routine operation area.

2. Prepare slender needles. And put the disinfection rubber sheet 4cm away from the needle tip.

[Operation method]

(I) Extraoral Injection

1. Injection point: Under the zygomatic arch, the midpoint of the sigmoid notch is used as the needle insertion point.

2. Process: Inject a small amount of anesthetic under the skin, and insert the needle vertically into the outer plate of the sphenoid wing. At this time, back the rubber sheet 1cm away from the skin, that is, the depth of the needle to the pterygopalatine depression, not more than 5cm. Retreat the needle to the skin to make the needle tip upward 10 °, and insert the needle 15 ° forward until the adjusted rubber piece touches the skin. Inject 3 to 4ml of blood when the blood is drawn back.

(B) Pterygium tube injection

1. Needle entry point: Use a 25-gauge slender needle to pierce the marked mucosal depression projected from the contralateral mouth corner to the ipsilateral large hole on the affected side.

2. Process: Inject a little medicine after puncturing. Then move the syringe to the affected side and carefully probe into the pterygopalatine canal. At this time, the injection needle is at 45 ° to the maxillary surface. Slowly advance the needle to a depth of about 3 cm. When the blood is drawn back, 2 to 3 ml of medicine is injected.

(Three) posterior orbital fissure

1. Needle entry point: puncture from the corresponding vestibular sulcus of the maxillary second molar.

2. Process: The bevel of the needle tip is 30 ° along the sacroiliac plane and the sagittal plane, and it sticks upward and inwardly into the temporal surface of the maxilla and advances 30 ° to the plane of the maxillary teeth. The depth is 3cm. Inject 2 to 4 ml of anesthetic.

Anesthesia Area

On the same side, the entire upper jaw and nose, lower eyelid, upper lip and soft and hard palate.

Anesthetic effect

The ipsilateral upper lip and palate has numbness, swelling, dry and blocked nasal cavity, and may also have nausea and vomiting.

Maxillary nerve and maxillary nerve related diseases

Trigeminal neuralgia: Trigeminal neuralgia is a type of paroxysmal severe neuralgia that recurs rapidly in the facial trigeminal nerve distribution area. Some people call this pain "the world's first pain." Trigeminal neuralgia is one of the common diseases in neurosurgery. Most of them start on the age of 40, especially in women, and the incidence is more on the right than on the left. Trigeminal neuralgia can be divided into two categories: primary (symptomatic) and secondary. Of these, primary trigeminal neuralgia is more common and may be caused by ectopic impulses or pseudosynaptic transmission of the demyelination of the trigeminal nerve.

Clinical characteristics:

1. The main symptoms are severe electric shock, knife-cut or tear-like pain that lasts for a few seconds each time, and suddenly stops, usually without warning, and the interval is completely normal. The pain is most pronounced on the cheeks, jaws, and tongue. Touching the nose, cheeks, and tongue can be induced, these points are called trigger points. Usually, washing the face and brushing the teeth can easily induce the pain of the second trigeminal nerve. Chewing, yawning, and speech induce the onset of the pain of the third trigeminal nerve. As a result, the patient is afraid to wash his face, eat food, and shows complexion and depression.

2. Severe secondary symptoms are accompanied by reflex twitching of the facial muscles, and the corner of the mouth is drawn to the affected side, which is called painful twitching. May also be accompanied by flushing, conjunctival congestion, tears, and high skin temperature. Severe cases can occur day and night, insomnia or easy to wake up after sleep. Pain characteristics: sudden, sudden stop, lightning-like, knife-like, burning-like, intractable, unbearable severe pain occurs in the trigeminal nerve distribution area of the head and face. Talking, brushing your teeth, or breeze can cause throbbing pain. Patients with trigeminal neuralgia often don't dare to wipe their face, eat, or even drool, so it can affect normal life and work. The course of the disease can be periodic, with each episode being days, weeks or months, and the remission period being days or years. The longer the course of the disease, the more frequent the attack, the more severe the disease, and generally does not heal itself. Neurological examinations usually have no positive signs.

3. Misdiagnosis analysis is based on the location and nature of pain. Without other neurological symptoms and signs, the diagnosis of trigeminal neuralgia is generally not difficult.

(1) Trigeminal neuralgia needs to be distinguished from secondary trigeminal neuralgia and the following common diseases.

1) Secondary trigeminal neuralgia: often manifested as trigeminal nerve palsy and persistent pain, and combined with other cerebral nerve palsy, can be caused by multiple sclerosis, medullary cavity and skull base tumors. Head CT and MRI can be distinguished. Trigeminal neuralgia is often misdiagnosed as toothache, and some patients have a painful diagnosis before tooth extraction. Generally, toothache is a persistent dull pain, which is limited to the gums. It can be aggravated by hot and cold food. Local and radiological examinations can help identify it.

2) Atypical facial pain: It usually occurs in patients with depression and neuroticism, and the pain is vague, usually on both sides. Emotions are aggravating factors, and there is no trigger point on the face.

3) Sinusitis: It is local persistent dull pain, local tenderness, and inflammation, such as fever, leukocytosis, and purulent runny nose, can be confirmed by nasal examination and X-ray film.

(2) Trigeminal neuralgia should be distinguished from vascular migraine and headache-type epilepsy: clinically for children or adolescents with headache or abdominal pain, in addition to considering vascular migraine, there should be further consideration of headache-type epilepsy and abdominal type epilepsy. Identification of the two: In addition to headache and abdominal pain in patients with headache and abdominal epilepsy, in addition to headache and abdominal pain, it is also manifested as loss of contact with the surrounding environment, that is, disturbance of consciousness, and vascular migraine, except for a few people with syncope, is conscious; Patients with epilepsy often have limb twitches, while migraines have fewer convulsions. Patients with epilepsy can have seizures during sleep, and migraine attacks disappear during sleep; Headaches have a family history of about 70%; epilepsy patients often have epileptic discharges, while the EEG of migraine attacks is basically normal; anti-epileptic therapy, patients with headache and abdominal pain relieved, and migraine anti-epileptic drug treatment is ineffective , Can still be recurrent.

Maxillary nerve assisted examination

1. Primary inspection

(1) CT and MRI examination of the brain: cranial tumors and inflammation can be found. Inflammation is a common cause of secondary trigeminal neuralgia. Among the tumors, pontine cerebellar horn tumors account for the majority, of which cholesteatoma tumors are the first. Inflammation refers to pontine cerebellar horn arachnoiditis.

(2) Brainstem trigeminal evoked potential (BTEP): BTEP in patients with trigeminal neuropathy has abnormal changes, and peripheral neuropathy and central neuropathy have different BTEP performance, so it can be used as a new and reliable assessment of trigeminal nerve function Electrophysiological methods.

2. Secondary blood glucose or glucose tolerance test: Some patients still need blood glucose or glucose tolerance test to exclude diabetic neuropathy.

Treatment points:

1. The principle of treatment is for the purpose of analgesia. Drugs should be used first, and nerve block or surgery can be used when it is ineffective.

2. Specific treatment methods

(1) Basic treatment

1) The treatment of secondary trigeminal neuralgia: should be based on the cause, otherwise the goal of radical cure cannot be achieved.

2) Treatment of primary trigeminal neuralgia: drug treatment is mainly used for those with short course and mild disease. Commonly used drugs include analgesics and sedatives. Some scholars believe that primary trigeminal neuralgia is a kind of "epileptic neuralgia", and its seizure properties are similar to epilepsy. Therefore, antiepileptic drugs such as phenytoin sodium and amimidazine have been used in clinical practice, and some Curative effect. These drugs should be taken under the guidance of a specialist. When the drug treatment is not effective, absolute ethanol can be used as a closed treatment. This method is suitable for various patients, especially those who are old and infirm, generally poor or unwilling to undergo surgery. After the above treatments are ineffective, patients with frequent attacks or relapses should consider surgery.

(2) Drug Therapy: Carbamazepine: 0.2 0.6g / d, divided into 2 or 3 times, 1.2g daily. Start 2 times a day, and later 3 times a day. There is analgesic effect after taking the medicine for 24 to 48 hours. Sodium phenytoin: white powder, odorless, slightly bitter. Soluble in water, almost insoluble in ether or chloroform, and deliquescent in air. Traditional Chinese medicine treatment: Chinese medicine advocates dialectical treatment for this disease, and provides targeted treatment according to different types.