What to do if the nerve in the lower jaw is affected when installing implants

Causes of the disease

Most often, optic neuritis develops with multiple sclerosis and is its first manifestation. The basis of the inflammatory process in this case is demyelination, or destruction of the myelin sheath of the nerve. Damage to the optic nerve is also provoked by other autoimmune pathologies: systemic lupus erythematosus, Sjogren's syndrome.

Diseases associated with serum immunoglobulin G to myelin-oligodendrocyte glycoprotein (MOG-IgG), in particular acute disseminated encephalomyelitis, also lead to demyelination and, as a consequence, optic neuritis.

Axons and neurons of the optic nerve are destroyed not only as a result of demyelinating processes, but also against the background of other diseases. These include:

• inflammation of the eyeball and/or orbit;
• inflammatory diseases of the brain;
• infectious processes in the nasopharynx;
• sarcoidosis, granulomatosis;
• acute cerebrovascular accident;
• endocrine pathologies – thyrotoxicosis, diabetes mellitus;
• specific infections - tuberculosis, syphilis, influenza.

Optic neuritis can be a consequence of eye injury, traumatic brain injury, toxic damage - in most cases it is poisoning with methyl alcohol, lead, and sometimes helminthic infestations. May be provoked by complicated pregnancy.

First signs of damage

The first symptoms of nerve damage are discomfort in the gums, cheeks, and lower lip. Manifestations of the problem are:

• paresthesia, that is, a change in the level of sensitivity without pain;
• dysesthesia with pain in the affected area, a feeling of “pins and needles”, changes in the general sensitivity of the area;
• anesthesia - complete loss of sensation in a certain area.

In some cases, the lingual nerve, which runs from the side of the tongue into the gum tissue, may be affected. This is usually observed as a result of the removal of "eights" (in approximately 2.1% of all cases). When implanted, this nerve is affected less frequently. If this situation occurs, the following symptoms appear:

• salivation becomes profuse;
• involuntary biting of the tip of the tongue appears;
• diction disorders;
• burning sensation, numbness in the tongue;
• loss, change in taste;
• swallowing is impaired.

In 90% of cases, the problems go away on their own within seven to ten weeks; no special treatment is required.

Symptoms of optic neuritis

Symptoms vary depending on the type of disease: intrabulbar (papillitis) or retrobulbar neuritis.

Papillitis (intraocular, retrobulbar neuritis)

It is characterized by an acute onset with a rapid deterioration in visual acuity - from 1-2 hours to 1-2 days. In some cases, mild headache and pain when moving the eyes occur. With partial damage, visual acuity may be preserved, but scotomas appear - areas of partial or complete loss of the visual field, which can be central or paracentral, round or arch-like. There may be a narrowing of the boundaries of the visual field, a decrease in dark adaptation and color perception. Most often, symptoms of visual impairment disappear after 7-10 days; after 2-3 weeks (sometimes up to 5 weeks), vision is restored. Without treatment or with severe neuritis, optic nerve atrophy with complete loss of vision is possible.

Retrobulbar neuritis

It occurs in acute or chronic form. The acute form is more often characteristic of unilateral lesions, the chronic form - for bilateral ones.

General symptoms:

• pain when moving the eyeballs and pressing on the eye;
• color vision disorders - decreased sensitivity of the eye to colors, shades quickly fade;
• a drop in visual acuity to the point of complete inability to distinguish objects;
• appearance of scotomas.

Depending on the form of retrobulbar neuritis, symptoms may vary. Axial neuritis is characterized by a combination of central scotoma with partial loss of visual fields and the appearance of peripheral defects in the visual field. In the peripheral form, the field of vision narrows along the entire perimeter - it is concentric in nature. The transversal form is characterized by a significant decrease in vision, up to blindness, scotomas merging with peripheral loss of visual fields.

Trigeminal and facial neuralgia

Neuralgia is a disease in which damage or compression of the trigeminal nerve and/or its branches occurs. This causes a sharp piercing pain that occurs suddenly and brings physical and psychological discomfort to the patient. Despite the fact that the term “neuralgia” can be literally translated as “nerve pain,” the matter is not limited to pain. Trigeminal and facial neuralgia are radically different in symptoms. The facial nerve contains mostly motor fibers, so neuralgia leads to dysfunction of the facial muscles (the degree depends on the severity of the disease), and can also cause lacrimation, dry eyes and partial loss of taste. Pain in facial neuralgia is usually concentrated in the area of ​​the parotid gland (the patient complains that the pain radiates to the ear), but there may be no pain at all. It is because of the lack of pain that some experts use the term “neuropathy” when talking about damage to the facial nerve. With the trigeminal nerve it’s exactly the opposite, since it contains many sensory fibers.

Classification and stages of disease development

Depending on the affected area:

• Intrabulbar (intraocular) neuritis, optic papillitis. This is an inflammation of the intraocular part (disc) of the optic nerve. More often develops in children.
• Retrobulbar neuritis. Damage to the nerve section lying between the eyeball and the optic chiasm. Forms of retrobulbar neuritisSource: Retrobulbar optic neuritis. Kukhtik S.Yu., Popova M.Yu., Tantsurova K.S. Bulletin of the Council of Young Scientists and Specialists of the Chelyabinsk Region, 2016: axial - a bundle of axons passing in the optic nerve is involved in the pathological process;
• peripheral - inflammation covers the nerve sheaths and spreads deep into the nerve trunk with the formation of a large amount of exudate under the sheaths;
• transversal - the process affects all layers of the optic nerve.

According to the etiology of the lesion:

• infectious:
• parainfectious (post-vaccination, after acute respiratory viral infections);
• demyelinating;
• ischemic;
• toxic;
• autoimmune.

According to the severity of the flow:

• spicy;
• chronic.

According to the prevalence of the lesion:

• mononeuritis – inflammation of one nerve (the vast majority of cases);
• polyneuritis – involvement of both optic nerves in the process (less than 1% of cases).

Probability of occurrence

The mandibular nerve fascicle is a fragment of the trigeminal nerve. It provides sensitivity to intraoral and facial tissues, and is responsible for contraction of the facial muscles and dentofacial apparatus. The bundle consists of motor and sensory fibers and nuclei.

The inferior alveolar nerve (IAN) is located in the lower jaw and is one of the three endings of the trigeminal nerve. The NAN borders the root system of the mandibular arch. In this regard, there is a high risk of damage during dental treatment.

The statistics of nerve damage are especially high during the period when dental operations were performed without the use of modern technologies.

According to the latest data, the incidence of nerve damage during dental implantation does not exceed 3%. Of this number, only 1.7% end up with permanent neuropathy.

According to some dentists, these data are underestimated, and the percentage of damage to NAS reaches 30%. In any case, this issue should be given sufficient attention.

Diagnosis of the disease

As a rule, patients who have the first symptoms of optic neuritis turn to an ophthalmologist. The disease is considered an interdisciplinary pathology; an ophthalmologist or neurologist must take part in its treatment. If neuritis develops against the background of other pathologies, it is necessary to clarify the diagnosis and carry out specific therapy for the primary diseases. Source: Visualization of the optic nerve in the diagnosis and monitoring of retrobulbar neuritis. Yuryeva T.N., Burlakova E.V., Khudonogov A.A., Ayueva E.K., Sukharchuk O.V. Acta Biomedica Scientifica, 2011. p. 133-136. Then the appropriate specialists are involved in the treatment - an immunologist, an otolaryngologist, an infectious disease specialist, a phthisiatrician.

The first step in diagnosing optic neuritis is collecting anamnesis, external examination of the patient, and palpation. During the medical history, the doctor will clarify the presence of concomitant pathologies, the time of onset of the disease, what complaints the patient has (pain, decreased visual acuity, changes in color perception, the appearance of “blind” spots), how quickly the symptoms developed and how severe they are, whether one eye or both is affected.

External examination and palpation may often not provide additional data. Pain, forward displacement of the eyeball, and limitation of its movements may occur with retrobulbar neuritis, but are not obligatory.

Next, the doctor proceeds to an ophthalmological examination. It includes:

• determination of visual acuity;
• the study of color perception is carried out using Rabkin’s polychromatic tables;
• study of pupil reaction to light;
• measurement of intraocular pressure, which can be a symptom of glaucoma and other diseases that provoke the development of neuritis;
• biomicroscopy – examination of the anterior segment of the eye to exclude its pathology;
• ophthalmoscopy (examination of the fundus of the eye) after instillation of drops that dilate the pupil;
• computer examination of visual fields at 120 points;
• study of visual fields using kinetic perimetry.

To clarify the diagnosis, the following methods are used:

• electrophysiological diagnostics - study of the threshold of electrical sensitivity of the retina and visual evoked potentials;
• ultrasound examination of the eyes, MRI of the orbit of the eye and brain;
• coherence tomography of the optic nerve;
• fluorescein angiography of the retina.

Laboratory diagnostics:

• general blood analysis;
• blood for HIV, syphilis, rheumatoid factor;
• blood culture for sterility;
• PCR studies;
• histological, immunochemical analysis.

If the patient has concomitant diseases, he is prescribed consultations with specialists.

Classification

In accordance with Seddon's classification, the following types of NAS injuries are distinguished:

1. Neuropraxia. This injury is reversible; the sheath of the nerve fibers does not suffer, that is, there is no development of degeneration. After treatment, the problem goes away, which usually takes a couple of weeks.
2. Axonotmesis. A reversible type of lesion, for which long-term, intensive treatment is prescribed - from three to six months. The development of degeneration and fiber damage are observed.
3. Neurotmesis. A serious disorder affecting all structures, including fibers and connective membranes. Scar tissue develops, and surgery is indicated to correct the problem.

In accordance with the generally accepted WHO classification, there are five categories of NAS injuries:

• compression, nerves are not damaged;
• swelling of tissues;
• partial rupture of fibers;
• complete ruptures of the NAS are observed;
• post-traumatic fibrosis develops.

Assessment methods

To determine the cause and extent of the disorder, diagnostics are required. For this purpose they prescribe:

• mechanoceptive methods, in which the response to mechanical irritation and stimulation is recorded;
• nociceptive, allowing to determine sensitivity to painful stimulation.

The first type of research includes tests of the following types:

• tests with a brush, during which the Patient’s lip is passed with a brush and asked to determine the direction of movement;
• two-point irritation using a probe.

The second diagnostic method includes:

• pin tests;
• Temperature tests for sensations of cold or heat.

Tests are also carried out for the presence of deficits in the sense of taste, and data from the right and left sides of the maxillofacial apparatus are compared. The accuracy of the research should be no more than 1 mm.

Treatment

The following regimens are used for therapy:

• observation of the Patient at intervals of 2, 3, 4, 6 months;
• drug therapy;
• unscrewing, removing the implant;
• microsurgical intervention.

There is no strict protocol; tactics are determined individually in each case. But there are limitations to surgical intervention - it will be effective only in the first year, after which this method is considered ineffective.

Drug therapy includes:

• taking painkillers;
• use of hydrogen pump blockers;
• prescription of anti-inflammatory drugs (glucocorticosteroids are prescribed);
• therapy for sensory impairment.

If symptoms appear in the first 1.-1.5 days after installation of the implant, its removal may be indicated. During this period, the prognosis is favorable, but over a longer period of time, removing the artificial root will no longer bring a noticeable improvement. The reason is irreversible changes in nerve fibers.

Surgery is indicated in cases where all previous measures have not brought the expected effect. To do this, the doctor must determine the location of the NAS and evaluate sensitivity disorders. The effectiveness of the operation is influenced by the following factors:

• time between injury and surgery;
• severity, type of lesion;
• blood supply;
• Preparation;
• tension zone;
• Patient's age, health status.

Predictions and prevention

Treatment has an uncertain prognosis; with microsurgical intervention, the positive result is in the range of 55-82%. If the damage is severe, complete recovery does not occur with any treatment method. According to some experts, complications such as pain persist even after the intervention. It is also worth noting that the success of treatment depends entirely on the extent of the lesion. It is impossible to guarantee a high result in any situation, that is, the forecasts are uncertain.

To avoid complications, prophylaxis is recommended. This is a mandatory full examination before the implantation procedure. The specialist will determine the exact location of the nerve, the topography of the nerve trunks and the maxillofacial system. This allows you to exclude the development of pathology and conduct conduction anesthesia correctly, without the risk of complications.

The main preventive measures include:

• competent selection of implantation system;
• diagnostics, including CT, production of a surgical template, computer modeling;
• planning the procedure for introducing an artificial root;
• determining the paths of nerve trunks, ensuring the distance between them and implants is not less than 2 mm;
• when drilling, it is necessary to avoid excessive force;
• When immersing a drill or implant, stoppers are used to limit the depth and ensure safety.

Treatment of damage to the mandibular nerve during implantation requires the doctor to have high qualifications and experience. But even under such conditions, the success rate does not exceed 82%. Some complications may remain, such as numbness or soreness.

Treatment of optic neuritis

Treatment must be carried out in a hospital setting; it should begin as early as possible, in order to avoid the disease becoming chronic and developing complications. Source: Modern view on the problem of optic neuritis (systematic review). Krivosheeva M.S., Ioileva E.E. Saratov Scientific and Medical Journal, 2022. p. 602-605. For patients with optic neuritis, diet No. 15 is indicated - a general table, in the absence of indications for other types of therapeutic diets.

The basis of treatment is etiotropic therapy aimed at eliminating the primary disease that caused optic neuritis. Until the etiology of the disease is clarified, remedies are used to reduce the symptoms of inflammation, remove swelling, allergic manifestations, and improve metabolism. For this purpose:

• glucocorticosteroid drugs, if they are intolerant - non-steroidal anti-inflammatory drugs (prescribed in rare cases);
• antibacterial or antiviral therapy;
• antifungal agents to prevent fungal infection due to a long course of antibiotics;
• detoxification therapy – intravenous drip administration of saline solutions;
• antihistamines;
• diuretics;
• products that improve microcirculation;
• neuroprotectors;
• vitamins.

In addition to medications, physical therapy may be used to treat optic neuritis.

With papillitis, as well as the infectious-toxic etiology of the disease, the prognosis is more favorable than with other types of optic neuritis - in 75-90% of cases, with proper treatment, vision is completely restored. When the optic nerve is damaged due to autoimmune, demyelinating diseases, collagenosis, sarcoidosis, and specific infections, relapses often occur, incomplete restoration of vision, and nerve atrophy is possible. Source: Results of treatment of optic neuritis. Latypova E.A. Saratov Scientific and Medical Journal, 2022. p. 875-879.

Types of jaw nerve injuries

1. Neuropraxia is a minor injury: benign course, favorable prognosis. In the absence of damage to the integrity of the nerve bundle, independent regeneration occurs within a month and a half.
2. Axonotmesis is partial degeneration of the myelin sheath: restoration of nervous tissue is incomplete, possibly 1.5 months after damage. Medical attention is required.
3. Neurotmesis - complete damage: degenerative changes in biophysical, biochemical parameters of nervous tissue. The prognosis is poor: high risk of irreversible loss of sensitivity .

Disease prevention

To prevent optic neuritis, it is recommended to give up bad habits, promptly treat infectious diseases, avoid eye and head injuries, and visit specialized doctors in the presence of chronic pathologies.

Article sources:

1. Retrobulbar optic neuritis. Kukhtik S.Yu., Popova M.Yu., Tantsurova K.S. Bulletin of the Council of Young Scientists and Specialists of the Chelyabinsk Region, 2016
2. Visualization of the optic nerve in the diagnosis and monitoring of retrobulbar neuritis. Yuryeva T.N., Burlakova E.V., Khudonogov A.A., Ayueva E.K., Sukharchuk O.V. Acta Biomedica Scientifica, 2011. p. 133-136
3. Modern view on the problem of optic neuritis (systematic review). Krivosheeva M.S., Ioileva E.E. Saratov Scientific and Medical Journal, 2022. p. 602-605
4. Results of treatment of optic neuritis. Latypova E.A. Saratov Scientific and Medical Journal, 2022. p. 875-879