Effect of Inferior Alveolar Nerve Transection on the Inorganic Component of Molars of Rat Mandible.

The objective of the study was to determine the effects of inferior alveolar nerve transection on inorganic components in mandibular molars of the rat. We used 26 male laboratory rats of the Wistar strain for the study, age 7-9 weeks. The rats were divided in three groups. The control group (intact) included 6 rats. The surgery was performed under general anesthesia. The experimental group included (group with the nerve transected on the left) included 12 rats. The sham group (group with the nerve prepared without transection) included 8 rats. The animals were sacrificed after 4 weeks. Molars from the left and right sides of the mandible were extracted. Element content levels were determined using inductively coupled plasma mass spectrometry. The following elements were determined in all samples: magnesium (Mg), sodium (Na), potassium (K), calcium (Ca), zinc (Zn), and strontium (Sr). The nerve transection caused: a reduction of the contents of Ca and Sr in the mandibular molars; an increase in the contents of Mg and Zn; a difference arrangement of both sides for Na. The surgery approach itself caused a decrease in the contents of Na and K in the experimental and sham groups; the difference in K in M3 between the left and right sides disappeared due to the surgery. Our results have confirmed the hypothesis of inferior alveolar nerve transection having an effect on inorganic components in mandibular molars in the rat.

Effect of inferior alveolar nerve transection on the inorganic component of bone of rat mandible.

OBJECTIVE: The aim of the study was to test the effect of transecting the inferior alveolar nerve on the inorganic bone component of the rat mandible. METHODS: 7-9 weeks old, male Wistar rats were used for the study. The animals were divided in 3 groups: control, experimental (nerve was transected) and sham (nerve was only prepared but not transected). After 4 weeks, the animals were killed, their teeth were extracted, and the mandibular bone was divided in 4 parts. Inductively coupled plasma mass spectrometry was used to the levels of 7 elements in the bone. RESULTS: The study results demonstrate that transection of the inferior alveolar nerve caused a decrease in calcium, iron, and strontium, and an increase of zinc. It caused the differences in potassium contents between the sides was significantly lower in the experimental group. The increase in the magnesium content, and decrease of sodium and potassium in the experimental group, as well as differences in the contents of: magnesium, sodium, potassium, iron and zinc between individual locations in the mandible are associated with the surgical approach. CONCLUSION: The results support our hypothesis - that sensory innervation has an impact on the inorganic component of the mandibular bone.

Does the Length of Dental Implants Inserted in Areas of Inferior Alveolar Nerve Lateralization Interfere on Mandibular Resistance to Fracture?

The aim of this study was to compare, in vitro, the mechanical resistance to vertical displacement of the mandible after osteotomy for lateralization of the inferior alveolar nerve and installation of dental implants. One hundred eighty polyurethane mandibles were equally divided into 6 groups: G1-intact hemi-mandibles (control group), G2-hemi-mandibles after osteotomy for lateralization of the inferior alveolar nerve, G3-hemi-mandibles with installation of 3 bicortical dental implants (3.75 × 13 mm), G4-hemi-mandibles with installation of 3 dental implants that did not reach the basal cortical bone (3.75 × 11 mm), G5-hemi-mandibles after osteotomy for lateralization of the inferior alveolar nerve and installation of 3 bicortical dental implants (3.75 × 13 mm) and G6-hemi-mandibles after osteotomy for lateralization of the inferior alveolar nerve and installation of 3 dental implants that did not reach the basal cortical bone (3.75 × 11 mm). The specimens were subjected to linear loading tests. The highest mean value of maximum load was found in G1 (412.36N ±â€Š11.99), followed by G2 (396.87N ±â€Š23.94), G3 (319.63N ±â€Š57.28), G4 (303.34N ±â€Š18.25), G5 (231.75N ±â€Š63.64) and G6 (228.13N ±â€Š20.75). Based on this data, it can be concluded that the bicorticalization (or not) of the implants was not a statistically significant risk factor for the vertical displacement of polyurethane hemi-mandibles.

Piezoelectric Surgery in the Inferior Alveolar Nerve Lateralization With Simultaneous Implant Placement: A Case Report.

The aim of this case report was to describe the inferior alveolar nerve (IAN) lateralization technique using the piezoelectric device for the posterior rehabilitation of an atrophic mandible with implants. The patient presented the absence of elements 35 and 36 associated with a vertical defect impairing the adequate dental implant placement without IAN damage. A full-thickness mucoperiosteal flap was raised, and a bone window was made with a piezoelectric device centralized on the IAN canal position. After dissection, the IAN was moved buccally with a sterile elastic strip. Morse cone 4.0 × 1.5-mm implants were inserted while the IAN remained retracted. At the 4-month follow-up, the screw-retained prosthesis was installed guaranteeing the recovering masticatory function. In conclusion, the case report showed that the IAN lateralization performed with an adequate surgical technique can be successfully indicated for longer implant placement in edentulous atrophic posterior mandible with no permanent neural damage.

The Risk Factors that Can Increase Possibility of Mandibular Canal Wall Damage in Adult: A Cone-Beam Computed Tomography (CBCT) Study in a Chinese Population.

BACKGROUND The objective of this study was to analyze the factors that can increase the possibility of mandibular canal (MC) defect in Chinese people, to evaluate the risk of nerve impairment, and to choose the proper operative method to reduce the risk of mandibular alveolar nerve injury during the extraction of mandibular third molar (MTM). MATERIAL AND METHODS A total of 954 patients (1,304 MTMs) who underwent orthopantomography (OPG) and cone-beam computed tomography (CBCT) between July 2014 and December 2014 were included in this study. The age and gender of patients, impacted type (high impaction, moderate impaction, and low impaction), Winter classification of MTM, position of MTM relative to MC, vertical classification of MTM and MC, and the feature images of OPG were collected and compared to the imperfection of the MC wall in CBCT images. RESULTS The wall situation of MC was significantly correlated with the age of the patient, the depth of the molar, the position of the roots, and six imaging appearances on OPG. There was no significant difference based on gender. CONCLUSIONS Most incomplete walls of MCs could be inferred by OPG. However, images based on CBCT could clarify the defect of the MC and also could clearly display the spatial relationship between the root and inferior alveolar canal.

The Status of Affected Infraorbital Nerve and Inferior Alveolar Nerve in Patients With Jaw Fibrous Dysplasia: A Clinical and Radiographic Evaluation.

The affected infraorbital nerve (IFBN) and inferior alveolar nerve (IFAN) status in patients with jaw fibrous dysplasia has not been definitely depicted. In this study, the authors try to explore the status of affected IFBN and IFAN in patients with jaw fibrous dysplasia. Ten patients with jaw fibrous dysplasia were included in this study. The complaints of numbness in the IFBA and IFAN innervated area were asked and recorded, and careful clinical examination was performed to evaluate the touch sense, pain sense, pressure sense, and temperature sense in the IFBA and IFAN innervated areas. Computed tomography scans also were performed to evaluate the imaging characteristics of affected IFBA and IFAN. The results showed that 1 patient with maxillary lesion showed complaints of slight numbness, and clinical examination showed that the patient exhibited slight insensitive in pain sense. In addition, 1 patient with mandibular lesion showed relative obvious complaints of numbness, and clinical examination showed that the patient exhibited slight insensitive in pain sense and temperature sense, but not serious. All other patients exhibited no numbness in the IFBA and IFAN innervated area. Although the position and morphology changed in some patients, all neural canal of affected IFBA or IFAN existed and showed no invasion of lesion. Taking these findings together, it further confirmed that evaluation of the function of IFBAN and IFAN is necessary for patients with jaw fibrous dysplasia, and the affected IFBAN and IFAN may should be reserved in most patients with jaw fibrous dysplasia when resecting or recontouring the lesion.

Inferior alveolar nerve function recovers after decompression of large mandibular cystic lesions.

OBJECTIVE: The treatment of large mandibular cystic lesions (diameter > 35 mm) is controversial. Few studies determine the inferior alveolar nerve function after decompression which is one of the major options for treating such lesions. We aim to investigate the recovery of inferior alveolar nerve function after decompression. METHODS: Twenty-two patients with large mandibular cystic lesions, diagnosed as keratocystic odontogenic tumor, ameloblastoma, or dentigerous cyst, were included. Inferior alveolar nerve function was observed by monitoring the pulp vitality of involved teeth (n = 64) with electric pulp test before decompression and 1, 3, 6, 9, 12, and 24 months after decompression, respectively. RESULTS: The pulp vitality of the involved teeth was significantly decreased before decompression. Recovery of pulp vitality could be observed after decompression, indicating the recovery of inferior alveolar nerve function. A majority (96.9%) of the vital pulp was preserved in the involved teeth after decompression. CONCLUSIONS: Recovery of inferior alveolar nerve function was remarkable in patients with large mandibular cystic lesions after decompression, indicated by the recovery of pulp vitality of involved teeth. When decompression is preferred, conservative therapy rather than root canal therapy is recommended for the teeth with root tip exposed in the cystic lesions and without pulposis.

Communications Between the Trigeminal Nerve and the Facial Nerve in the Face: A Systematic Review.

The aim of the article is to elucidate the communications between the trigeminal nerve and facial nerve in the face. In a PubMed search, 328 studies were found using the terms 'trigeminal nerve, facial nerve, and communication.' The abstracts were read and 39 full-text articles were reviewed. Among them, 11 articles were analyzed. In the studies using dissection, the maxillary branch (V2) had the highest frequency (95.0% ±â€Š8.0%) of communication with the facial nerve, followed by the mandibular branch (V3) (76.7% ±â€Š38.5%). The ophthalmic branch (V1) had the lowest frequency of communication (33.8% ±â€Š19.5%). In a Sihler stain, all of the maxillary branches and mandibular branches had communications with the facial nerve and 85.7% (12/14 hemifaces) of the ophthalmic branches had communications. The frequency of communications between the trigeminal nerve and facial nerve were significantly higher (P = 0.00, t-test) in the studies using a Sihler stain (94.7% ±â€Š1.1%) than the studies using dissection (76.9 ±â€Š35.8). The reason for the significantly higher frequency of trigeminal-facial communication in the studies using a Sihler stain is because of the limitation of the Sihler stain itself. This technique cannot differentiate the motor nerves from sensory nerves at the periphery, and a crossover can be misinterpreted as communication near to nerve terminal.

Short Lingual Osteotomy Using a Piezosurgery Ultrasonic Bone-Cutting Device During Sagittal Split Ramus Osteotomy.

Short lingual osteotomy is a useful method for the performance of sagittal split ramus osteotomy involving interference between the proximal and distal bone fragments when lateral differences exist in the setback distance. However, this procedure occasionally results in abnormal fracture and nerve injury; expert surgical skill is thus required. We herein describe a novel technique involving the use of an ultrasonic bone-cutting device (Piezosurgery; Mectron Medical Technology, Carasco, Italy) for vertical osteotomy posterior to the mandibular foramen. Successful short lingual osteotomy was performed using this technique with avoidance of abnormal fracture and neurovascular bundle damage.

A Technique for Preoperative Identification of the Facial Nerve Mandibular Branch Using a Nerve Stimulator.

We established the method of preoperative identification to facial nerve marginal mandibular branch (FNMB) identification using a nerve stimulator with bipolar probe for upper-neck surgery. The bipolar electrode is placed on the region while patients were awake; the patient should be in the same position and posture as during the surgery, with the neck skin stretched. A nerve course is confirmed by observing the movement of the lower lip. In this study, 5 upper-neck surgeries were conducted. Preoperative analysis revealed that 4 of the 5 cases had 2 branches of FNMB, and 1 with 3 branches. All FNMB immediately confirmed preoperatively were identified during surgery. We performed this method in much surgery including the surgery of the upper neck. It was easy to identify the facial nerve by this method and came to be able to do it precisely, and an operative time was shortened. We concluded that the preoperative FNMB identification using a nerve stimulator is most useful and benefit for upper-neck surgery patients and lead to avoid lower lip paralysis.

Pain. Part 2a: Trigeminal Anatomy Related to Pain.

In order to understand the underlying principles of orofacial pain it is important to understand the corresponding anatomy and mechanisms. Paper 1 of this series explains the central nervous and peripheral nervous systems relating to pain. The trigeminal nerve is the 'great protector' of the most important region of our body. It is the largest sensory nerve of the body and over half of the sensory cortex is responsive to any stimulation within this system. This nerve is the main sensory system of the branchial arches and underpins the protection of the brain, sight, smell, airway, hearing and taste, underpinning our very existence. The brain reaction to pain within the trigeminal system has a significant and larger reaction to the threat of, and actual, pain compared with other sensory nerves. We are physiologically wired to run when threatened with pain in the trigeminal region and it is a 'miracle' that patients volunteer to sit in a dental chair and undergo dental treatment. Clinical Relevance: This paper aims to provide the dental and medical teams with a review of the trigeminal anatomy of pain and the principles of pain assessment.

Inferior alveolar nerve function after sagittal split osteotomy by reciprocating saw or piezosurgery instrument: prospective double-blinded study.

PURPOSE: The aim of this prospective study was to objectively evaluate inferior alveolar nerve (IAN) sensory disturbances in patients who underwent sagittal split ramus osteotomy (SSRO) by comparing 1 side treated with a reciprocating saw with the other side treated with a piezosurgery device. MATERIALS AND METHODS: Clinical evaluation of IAN sensory disturbance was undertaken preoperatively and at 1 week, 4 weeks, 2 months, and 6 months postoperatively in 20 patients who underwent SSRO at the Division of Oral and Maxillofacial Surgery, Araraquara Dental School, São Paulo State University. The 20 patients were examined at all periods for IAN functionality by Semmes-Weinstein testing; neither the patients nor the examiner knew which side was treated using piezosurgery or a reciprocating saw. RESULTS: The mean age of the patients was 28.4 years (range, 20 to 48 yr). Before surgery, no patient had impaired function of the IAN in any of the 8 zones in the mental and inferior lip areas. All patients reported feeling the first monofilament at the time of the preoperative test. Seven days postoperatively, all patients reported some kind of altered sensitivity in at least 1 zone evaluated. CONCLUSIONS: The results of this study suggest there was no statistically significant difference in the sensitivity of the labiomental area regarding the instrument used to perform the osteotomy. Future studies will focus on enlarging the sample and evaluating the results.

Inferior alveolar nerve regeneration after bifocal distraction osteogenesis in dogs.

PURPOSE: Bifocal distraction osteogenesis has been shown to be a reliable method for reconstructing missing bone segments. However, no reports have been published regarding inferior alveolar nerve regeneration during this procedure. We assumed that the nerve could regenerate with the bone regeneration during bifocal distraction, if the nerve had been saved at a mesial site of the transport disc. In the present study, we investigated that possibility in dogs. MATERIALS AND METHODS: Using a bifocal distraction osteogenesis method, we produced a 10-mm mandibular defect, including the nerve defect, and distracted the transport disc at a rate of 1 mm/day in 12 dogs. The nerve was saved at the mesial site of the transport disc. The regenerated nerve was evaluated by a jaw opening reflex examination performed once daily. Histologic examinations with hematoxylin-eosin and immunohistochemical staining with neurofilament and S-100 antibody were also performed on all dogs after death at 3, 6, and 12 months after the first operation. RESULTS: The jaw opening reflex had recovered in all dogs. The average period of recovery was 109.5 ± 24.7 days. On histologic examination, although consecutive nerves were observed in all areas, cellular nerve fascicles were seen, consistent with wallerian degeneration at 3 and 6 months in the nerve connection area on the distal side of the transport disc. CONCLUSIONS: Our results have indicated that inferior alveolar nerve regeneration after bifocal distraction osteogenesis is successful in dogs. Although our research is still at the stage of animal experiments, future application in humans can be considered to be possible.

Prospective clinical assessment of pulp sensitivity after chin bone harvesting.

PROPOSAL: Evaluate pulp vitality of mandibular teeth after chin bone harvesting. MATERIALS AND METHODS: Thirty patients underwent chin bone harvesting and accompanied for 12 months, being submitted to testing for pulp vitality with Endo Ice refrigerant spray to produce a local temperature of -50 °C. The statistical analysis was executed with McNemar test with P value < 0.05. RESULTS: Results show that canine teeth are most susceptible to alterations; 68.82% (181) of the teeth tested showed no loss of pulp sensitivity to cold 30 days after surgery (P < 0.05), and at the end of the study, that figure had risen to 100% (263) of all teeth included in the sample. CONCLUSIONS: Pulp vitality testing showed that 31.18% (82) of teeth experienced some loss of sensitivity, but by 12 months after surgery, all teeth had recuperated their pulp sensitivity to cold unaided.

[Diagnostics and treatment of acute odontogenic osteomyelitis of the mandible considering functional state of inferior alveolar nerve].

Evaluation of functional impairment of inferior alveolar nerve in acute odontogenic inflammatory processes was carried out in this clinical study by means of stimulation electroneurography. Possibility of early diagnosis of acute odontogenic osteomyelitis by this method and effectiveness of decompression osteoperforation for its treatment was shown.

The effect of minocycline on the masticatory movements following the inferior alveolar nerve transection in freely moving rats.

BACKGROUND: To determine the effects of inferior alveolar nerve transection (IAN-X) on masticatory movements in freely moving rats and to test if microglial cells in the trigeminal principal sensory nucleus (prV) or motor nucleus (motV) may be involved in modulation of mastication, the effects of microglial cell inhibitor minocycline (MC) on masticatory jaw movements, microglia (Iba1) immunohistochemistry and the masticatory jaw movements and related masticatory muscle EMG activities were studied in IAN-X rats. RESULTS: The number of Iba1-immunoreactive (IR) cells both in prV and motV was significantly larger in IAN-X rats compared with sham rats on day 3 after IAN-X. The intraperitoneal (i.p.) administration of MC caused a significant reduction of the number of Iba1-IR cells both in prV and motV that was evident on day 14 after IAN-X. Furthermore, a significant reduction of the number of Iba1-IR cells could be observed in motV but not in prV after microinjection (m.i.) of MC into the motV of IAN-X rats. The rats also exhibited a significant decrease in the head-withdrawal threshold on the side ipsilateral to the IAN-X compared to the threshold before IAN-X and it lasted to day 14. In addition, IAN-X markedly affected the ability to rat to carry out mastication. The number of complete masticatory sequences was significantly decreased. Furthermore, the total masticatory sequence time and food preparatory (PP) period duration was significantly elongated in compared to sham rats. Although IAN-X significantly affected the total number of chewing cycles within the RC period of a masticatory sequence, it had no effect on the duration of the chewing cycles. On the other hand, systemic administration of MC (both i.p. and m.i.) in IAN-X rats significantly improved decreased head-withdrawal threshold and the impaired masticatory jaw movements. CONCLUSIONS: The present findings reveal that the strong modulation of masticatory jaw movements occurs following microglial cell activation after IAN-X, and the modulation recovers after inhibition of the microglial cell activation by MC, suggesting that microglial cell activation in the motV as well as in the prV has a pivotal role in modulating mastication following trigeminal nerve injury associated with orofacial neuropathic pain.

Subjective alveolar nerve function after bilateral sagittal split osteotomy or distraction osteogenesis of mandible.

PURPOSE: The present retrospective cohort study compared the subjective inferior alveolar nerve (IAN) function after distraction osteogenesis (DOG) and bilateral sagittal split osteotomy (BSSO) in mandibular advancement surgery. MATERIALS AND METHODS: Treatment consisted of correction of a retrognathic mandible using DOG (30 patients) or BSSO (35 patients). Subjective IAN function was recorded using a questionnaire 1 year after surgery. A total of 130 IANs were evaluated. RESULTS: In 37 nerves (28.5%), an IAN disturbance was observed. In this group of 37 nerves, BSSO had been performed in 26 (70.3%) and DOG in 11 (29.7%). After eliminating confounders (eg, age, amount of advancement, gender), no significant difference (odds ratio 0.652, 95% confidence interval 0.221 to 1.920) was found. Age was significantly related to subjective IAN disturbances for women but not for men. This was seen in women older than 22 years and increased for women older than 36 years to an odds ratio of 22.8 (95% confidence interval 2.580 to 201.488). Satisfaction also correlated with age, independent of gender. CONCLUSION: No difference was found in subjective IAN disturbances after 1 year between DOG and BSSO for lengthening the mandible.

Microsurgical repair of the inferior alveolar nerve: success rate and factors that adversely affect outcome.

PURPOSE: The objectives of this study were to determine the likelihood of regaining functional sensory recovery (FSR) after microsurgical repair of the inferior alveolar nerve (IAN), and which variables significantly affected the outcome of that surgery in a large series of patients. MATERIALS AND METHODS: This was a retrospective cohort study that evaluated all patients who had undergone microsurgical repair of the IAN by 1 of the senior surgeons (R.A.M.) from March 1986 through December 2005. The requirements for inclusion of a patient in the study included the availability of a complete chart record and a final follow-up visit at least 12 months after surgery. All other patients were excluded. The predictor variables were categorized as demographic, etiologic, and operative. The final outcome variable was the level of recovery of sensory function as determined by standardized neurosensory testing at the last postoperative visit of each patient and based on guidelines established by the Medical Research Council Scale. Risk factors for surgical failure to achieve useful sensory function were determined from analysis of descriptive statistics, including patient age, patient gender, etiology of nerve injury, chief sensory complaint (numbness, pain, or both), time from injury to surgical intervention (in months), intraoperative findings, and surgical procedure. Logistic regression methods and associated odds ratios were used to quantify the association between the risk factors and improvement. Receiver operator characteristic curve analysis was used to find the threshold of those variables that significantly affected patient outcome. RESULTS: In total, 167 patients (41 male and 126 female patients; mean age, 38.7 years [range, 15-75 years]) underwent 186 IAN repairs (19 patients sustained bilateral IAN injuries). The mean time from injury until surgery was 10.7 months (range, 0-72 months). Successful recovery from neurosensory dysfunction (FSR, defined by the Medical Research Council Scale as ranging from useful sensory function to complete sensory recovery) was observed in 152 repaired IANs (81.7%). With increasing duration from date of injury to IAN repair, the likelihood of FSR decreased (odds ratio, 0.898; P < .001). The odds of achieving FSR exhibited a linear decline between the date of nerve injury and its repair, with a significant drop in rate of successful outcome (FSR) occurring beginning at 12 months after injury. There was also a significant negative relationship between increasing patient age and improvement (odds ratio, 0.97; P = .015), with a threshold drop of achieving FSR at 51 years of age. The cause of the injury, the operative findings, and the type of operation performed to repair the nerve had no significant effect on the likelihood of the patient regaining FSR. The presence of pain after nerve injury did not affect the likelihood of achieving FSR after repair in a statistically significant manner (P = .08). In those patients who did not have pain as a major complaint before nerve repair, pain did not develop after microneurosurgery. CONCLUSIONS: Microsurgical repair of an IAN injury resulted in successful restoration of an acceptable level of neurosensory function (FSR) in most patients (152 of 186 repairs [81.7%]) in this study. The likelihood of regaining FSR was inversely related to both time between the injury and its repair and increasing patient age, with significant threshold drops at 12 months after nerve injury and at 51 years of age, respectively.

[Percutaneous mandibular nerve block using neuro-stimulation guiding through the sigmoid indentation in facial surgery]. / Bloc percutané du nerf mandibulaire à travers l'échancrure sigmoïdienne, guidé par neurostimulation, en chirurgie de la face.

INTRODUCTION: Mandibular nerve block is a simple and effective but rarely used technique. It decreases peri-operative pain in mandibular osteotomy. It improves surgical field visibility by decreasing bleeding. Mandibular nerve block allows cutaneous surgery without general anesthesia and is one of the alternative treatments for chronic facial pain. TECHNICAL NOTE: The mandibular nerve is located using a needle connected to a neurostimulator. After local disinfection, a neurostimulation needle is inserted below the zygomatic arch, between the coronoid apophysis in front, and the condyle process in back, with a 45 to 60° angle. The needle is pushed to a 40 mm depth. Masticator muscle contraction confirms mandibular nerve stimulation. After a careful negative aspiration, 5 mL of ropivacaine 0.5% are injected slowly, and in increments. DISCUSSION: The complications with this technique, such as failure or arterial puncture, are rare and limited if a nerve stimulator is used. Patient's comfort is improved by intravenous remifentanil sedation in target control infusion mode, associated to prior use of prilocaine and lidocaine cutaneous cream.

[State of lower alveolar and mental nerves by mandible fractures healing under transbone osteosynthesis].

Fracture of mandibular body at the level of P3-P4 with symphysis rupture was modeled, reposition and transosseous osteosynthesis with a specially developed device were performed under anesthesia in the operating room in 17 adult mongrel dogs in order to specify the pathogenesis and the dynamics of injury and jaw nerve regeneration. It has been established, that the arrangement of the neurovascular bundle in medullary canal predetermines the development of acute and chronic compression-and-ischemic neuropathy even if accurate reposition of bone fragments takes place. The histological signs of nerve fiber regeneration, the loss of the quantity of myelin-free nerve conductors and the retrograde spreading of degenerative changes in myelinized nerve conductors, including regenerating ones, have been found beginning from 4 weeks after injury. It has been concluded, that spontaneous nerve regeneration in case of mandibular fractures should be actively supported by neuroprotective, anti-edematous and anti-inflammatory therapy.