Changes in blink reflex after simultaneous supraorbital and mental nerve stimulations in healthy subjects.

Background/aim: In this study, we investigated the blink reflex (BR) after simultaneous and asynchronous stimulation of two trigeminal nerve branches. The objective was to characterize the physiology of trigeminal and facial circuits. Materials and methods: We performed three sets of experiments: recording BR response i. after supraorbital nerve stimulation (SON), after mental nerve stimulation (MN), and after simultaneous SON and MN stimulation (SON+MN) in 18 healthy individuals; ii. after MN (at an intensity eliciting BR response) preceding SON at various interstimulus intervals (ISIs) in seven healthy subjects; iii after MN (at sensory threshold) preceding SON at various ISIs. We compared the magnitudes of early and late responses. Results: The R1 amplitude after simultaneous SON+MN stimulation was greater than responses after single stimulation of the same branches. After simultaneous stimulations, the R2 and R2c areas under the curve (AUC) were smaller than the arithmetic sums of R2 and R2c AUC obtained after single stimulations. The second experiment provided a recovery excitability curve. In the third step, we obtained facilitation of R1 and inhibition of late responses. Conclusion: The SON+MN stimulation caused an increased R1 circuit excitability compared to the arithmetic sum of the single stimulations; however, magnitudes of late responses did not potentiate. Thus, we have provided evidence for R1 circuit enhancement by simultaneous stimulation in humans, whereas modulation of late responses exhibited a recovery curve similar to that shown for paired SON stimulation.

Evaluating the Anterior Loop of the Mental Nerve Using Cone Beam CT Scans in the Jordanian Population.

INTRODUCTION: Knowledge of anatomical landmarks is crucial for effective dental treatments, especially in surgical procedures. The mental nerve (MN), a branch of the inferior alveolar nerve, features a critical landmark known as the anterior loop (AL), often overlooked by surgeons. This study aims to assess the occurrence of the MN AL, its type, and its length within a sample of the Jordanian population by utilizing cone beam computed tomography (CBCT) scans. METHODS: This retrospective observational study included the acquisition of CBCT images from a total of randomly selected 268 patients who sought treatment for a range of dental conditions (such as tooth extraction, orthodontic therapy, and dental implants) at hospitals affiliated with the Jordanian Royal Medical Services. Reformatted images were utilized to detect the AL type, length, and the association between the nerve type and mental foramen (MF) position. RESULTS: This study involved 268 patients. The distribution of MF positions and the characteristics of the inferior dental nerve were evaluated, with no significant gender differences observed. The predominant location for the MF in both males and females in both sides was position IV, with 52% of females and 56-59% (left-right sides) of males presenting this trait. The inferior dental nerve types also showed no significant gender variation, with 42-43% (left-right sides) of females having type III and a similar distribution among males. Measurements of the midline-mental foramen and inter-foramen distances revealed slight variations between genders, with significant differences noted in the right AL length for type III nerves, favoring males (p=0.034). A notable correlation was found between the type of inferior dental nerve and the MF position, particularly with type I nerves predominantly associating with position IV mental foramina (p≤0.004). CONCLUSION: CBCT scans are essential in the precise evaluation of the AL, aiding in the prevention of nerve injuries during dental procedures. Our results highlight the diversity of the AL in the Jordanian population and the importance of individualized treatment plans. Future research with larger cohorts is advised to refine these insights, aiming to improve treatment outcomes and patient care.

Neurosensory Evaluation Following Genioplasty: A Case Report.

Genioplasty is a common procedure in plastic surgery, with various alloplastic biomaterials utilized for chin augmentation. Despite their advantages, complications such as neuropraxia of the mental nerve can occur, leading to temporary or persistent sensory disturbances. This case report describes a 35-year-old female who sought correction of a small chin. Preoperative evaluation revealed a retrognathic profile, and the patient underwent genioplasty with high-density porous polyethylene implantation. Postoperatively, she experienced mild paresthesia, which improved over time. Neurosensory assessments, including mechanical and light touch tests, showed no abnormalities in A-beta and C fibers but decreased sensitivity in A-delta fibers. This case report emphasizes the importance of evaluating larger nerve fibers during postoperative assessments and the need for standardized testing methodologies to comprehensively assess nerve damage after genioplasty. Further research should explore strategies to standardize neurosensory assessment and optimize therapeutic interventions for nerve damage after genioplasty.

Dental Pulp-Derived Mesenchymal Stem Cells Increase Axon Numbers in Mental Nerve Repair.

Aim: The mental nerve, the extended part of the inferior alveolar nerve, is often injured during dentoalveolar, orthognathic, or tumor surgery. Numerous therapeutic interventions, including surgery and pharmacotherapy, have been used to enhance the recovery of nerve injuries. Dental pulp stem cells (DPSCs) represent an easily accessible source of adult stem cells that can be isolated from the pulp of extracted teeth. This study evaluated the effect of DPSCs on the regeneration of the mental nerve injury model of rabbits. Methods: In this presented study, DPSCs were cultured and cell characterizations were performed by using flow cytometry and immunostainings. Bilateral mental nerve injury models of rabbits were created. In the control group (n = 10), saline was applied, and in the study group (n = 10), 2 × 106 DPSCs were applied to the repaired nerve areas. After 3 weeks, animals were killed and histological examination was obtained by using Masson's trichrome staining. An unpaired Student's t test was used when comparing the groups. Differences were considered to be statistically significant at P values of less than 0.05. Results: The DPSCs demonstrated a homogeneous population of mesenchymal stromal cells which expressed cluster of differentiation CD44, CD73, CD90, and CD105 and lack of CD34, CD45, and HLA-DR. Our finding clearly demonstrated that a lower number of cross-sectioned axons were founded in the control group (60.18 ± 2.52) compared to the study group (72.96 ± 2.43) (p = 0.00). Conclusions: DPSCs promote mental nerve axonal regeneration. These results suggest that DPSCs provide an important accessible source of adult stem cells for mental nerve regeneration.

The anterior loop of the inferior alveolar nerve within the mentonian foramen: a scoping review.

PURPOSE: The aim of this study is to delineate the safety zone concerning the anteriorization of the AL and correlate it with the behavior of the AL, analyzing its feasibility. METHODS: Adhering to the Joanna Briggs Institute (JBI) manual guidelines, both the protocol and this review were conducted based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR) checklist. MeSH terms, combined with free terms, were utilized to search for articles in the following databases: Embase, LILACS, LIVIVO, PubMed/MEDLINE, Scopus, Web of Science, and grey literature. RESULTS: Fifteen articles were select following the eligibility criteria. An average safe zone of 4.75 mm in humans was observed, with a prevalence 60.8% and average anterior length of the AL of 2.09 mm in humans. CONCLUSION: The AL has varied patterns across different populations, then, it could not be asserted a 100% safe zone. Preoperative analysis of the AL with CBCT is always necessary. While it could be stated that a safe zone should be employed as an inviolable region, stipulated measures of a safe zone should be regarded as an area of greater attention in preoperative planning.

Concurrent Impaction of the Mandibular Primary Second Molar and Second Premolar in Close Approximation to the Mental Nerve: A Case Report.

Impacted teeth are those that fail to erupt at the typical age of eruption and remain enclosed in the maxilla or mandible, partially or completely surrounded by bone or soft tissues. Among these, third molars experience the highest incidence of impaction, with maxillary canines and mandibular bicuspids following closely. A 23-year-old female presented to the orthodontics department, expressing concerns about spacing issues in her upper and lower front teeth. During the orthodontic planning process and radiological assessment, two impacted teeth, specifically one primary molar and one permanent premolar, were identified in close proximity to the mental nerve. Both teeth were subsequently extracted with success. This case report underscores the importance of a thorough preoperative radiographic evaluation of the mandibular canal and foramina. Additionally, it stresses the necessity for dissection to prevent unintended injury to the mental nerve during the extraction of the impacted mandibular premolar, which can result in paresthesia affecting the lower lip, mandibular labial gingiva, and chin.

Biomechanical analysis and comparison between 'Zeta' miniplate design and conventional miniplate system for fixation of fracture segments in transition zone of parasymphysis body region of mandible - an in vitro study.

The parasymphysis area of the mandible is highly dynamic because it is subjected to both occlusal and muscular forces. As a result, the fractures in this transition zone have a special pattern, posing a challenge for surgeons whether to use one miniplate versus two miniplates, as per Champy's recommendations. The commonest complication resulting to treat this area is mental nerve paraesthesia due to the dissection and stretching of the nerve. Hence, an in vitro research study of a newly designed 'Zeta' miniplate is performed, to evaluate the biomechanical behaviour using finite element (FE) analysis and biomechanical analysis along with a comparison study with the conventional miniplate configurations. The results showed that the Zeta miniplate produces the lowest stresses 17.511 MPa and the least total structural deformation of 0.0011 mm after applying the maximum occlusal bite force. On application of torsional load, total structural deformation was 0.0004 mm and von Mises (VM) stress value was 0.24 MPa which was lowest when compared with the two miniplate system. Hence, the newly developed Zeta miniplate is superior in terms of stability. Another benefit of its design is that it helps in preventing mental nerve paraesthesia and tooth root damage while fixing and stabilising the fractured bony segments.

Mentalis nerve branches supplying the lower lip revisited: a study of human fetuses and donated elderly cadavers.

PURPOSE: Little information is known about the mentalis nerve course from the lower lip approximation margin (free margin) to the upper lip. Likewise, no difference in nerve distribution has been observed between the cutaneous and mucosal parts of the lip. Therefore, this study reexamined mentalis nerve morphology. METHODS: For macroscopic observations, three fresh cadavers were dissected (one male and two females; aged 78-93). We also evaluated histological sections obtained from five donated elderly cadavers (two males and three females, aged 82-96 years) and 15 human fetuses (11-40 weeks or crown-rump length 80-372 mm). Immunohistochemical analysis for S100 protein and tyrosine hydroxylase was performed. RESULTS: In both fetuses and adult cadavers, one to three nerve branches ran upward in the submucosal tissue from the mental foramen. Near the free margin of the lip, some branches passed through the orbicularis oris muscle layer toward the lip skin, whereas others followed a reversed J-shaped course along the free margin. Nerve twigs ran in parallel beneath the mucosa, whereas wavy nerve twigs attached to the basal lamina of the lip epidermis. The difference in nerve endings abruptly occurred at the skin-mucosal junction. Tyrosine hydroxylase-positive sympathetic nerve twigs surrounded arteries and formed a branch composed of S100-negative unmyelinated fibers. CONCLUSION: The lower lip skin was innervated by a perforating branch passing through the orbicularis oris muscle, that was different from the lip mucosa. A sudden change in the nerve ending configuration at the mucocutaneous junction seemed to develop postnatally.

Assessment of the Anterior Loop and Pattern of Entry of Mental Nerve Into the Mental Foramen: A Radiographic Study of Panoramic Images.

INTRODUCTION: The precise location of the mental foramina is an essential landmark in planning the position of dental implants in the anterior mandible. Injury to inferior alveolar nerve during anterior mandibular implant surgery causes altered sensation which greatly affects patient satisfaction. METHODS: In this study, we assessed the prevalence of anterior loop of mental nerve and the pattern of entry of mental nerve into the mental foramen. Three hundred panoramic radiographs (600 hemimandibles) obtained from records maintained in the Department of Oral Medicine and Radiology were randomly selected for the study. The radiographs were evaluated by two independent observers for the pattern of entry of mental nerve into the mental foramen on either side of the mandible and for the presence or absence of anterior loop of mental nerve. RESULTS: The most prevalent pattern of mental nerve observed was Straight pattern which totals to 67.5% followed by Anterior loop pattern (18.8%) and then the Perpendicular pattern (13.7%). There was no significant association between the gender and subtypes of looping pattern on the left and right side and a highly significant association between the side of the mandible and loop pattern was observed by Chi square test. CONCLUSION: The Anterior loop pattern of mental nerve has been found in 18.8% of the population suggesting to accurate planning with three-dimensional imaging techniques to avoid injury to mental nerve during dental implant placement and other surgical procedure involving the interforaminal region of the mandible.

The alveolar canals and foramina in the first edition of Terminologia Oroanatomica: a preview.

Anatomy was initially developed out of necessity to decrease surgery complications. Over time, anatomists and surgeons have sometimes used different terms for the same anatomical structures, thus resulting in numerous discrepancies in terminology between anatomy and surgery. To avoid any confusion or misunderstanding and to better elucidate the oral anatomy terms, the Federative International Programme for Anatomical Terminology (FIPAT) organized a group of specialists on oral anatomy, Terminologia Oroanatomica (ToA) working group, composed of dentists, anatomy researchers, anatomy educators, oral and maxillofacial surgeons, and oral and maxillofacial radiologists. Within the ToA working group, major anatomical structures in the mandible, such as the mandibular canal, were focused and discussed to determine the most appropriate term, i.e., inferior alveolar canal. Although yet to be approved by the International Federation of Associations of Anatomists (IFAA), this article will preview some changes suggested by the ToA.

Relationship between age-related changes in mandibular third molar roots and the possibility of mental nerve paresthesia after tooth extraction.

Mental nerve paresthesia is a serious postoperative complication of mandibular third molar extraction. It appears that no study has examined the relationship between the surface morphology of the mandibular third molar roots and the possibility of mental nerve paresthesia following tooth extraction. Therefore, the root morphology of the mandibular third molars was examined according to age using dental cone beam computed tomography (CBCT), and the possibility of mental nerve paresthesia following tooth extraction was evaluated. The study included 1216 patients who had undergone mandibular third molar extractions. The root morphology of 1534 teeth in 791 patients who had CBCT performed before surgery was studied. Factors evaluated were age, complete or incomplete formation of the mandibular third molar roots, periodontal ligament atrophy of the mandibular third molar roots, hypercementosis, and mandibular canal deformation. Mandibular third molar root formation was completed between the ages of 19 and 30 years. Complete formation of the mandibular third molar roots (P = 0.002) and deformation of the mandibular canal (P < 0.001) were identified as risk factors for mental nerve paresthesia. These findings suggest that the risk of mental nerve paresthesia could be reduced if the extraction of third molars is performed prior to complete root formation.

A New Transoral Vestibulum Single Incision Endoscopic-Assisted Thyroidectomy with Gasless.

OBJECTIVE: We developed a novel method for thyroidectomy using a single-incision oral vestibular approach. To assess its advantages and disadvantages, we compared the perioperative parameters of this approach with those of transoral three-incision thyroidectomy and trans-areolar thyroidectomy. METHODS: In a study of 136 papillary thyroid carcinoma patients (2016-2018), precise thyroidectomy and neck dissection were conducted. Among them, 52 chose single-incision oral vestibular approach, 33 chose three-incision variant, and 51 underwent trans-areolar thyroidectomy. Perioperative aspects of the transoral single-incision group were compared with those of transoral three-incision group, and transthoracic group. RESULTS: In the cohort, meticulous tumor level VI lymph node dissection was performed, achieving intended resection extent with one case requiring a switch from transoral to transthoracic approach. No nerve palsy occurred in the transoral group. Thyroidectomy duration varied significantly across groups. Transoral single-incision had a shorter duration than transoral three-incision and longer than transthoracic. Minor differences were observed in blood loss and drainage. Perioperative factors like hematoma, infection, hypocalcemia, et al., remained consistent. Notably, no tumor recurrence was observed in this study. CONCLUSIONS: This new transoral video-assisted neck surgery (TOVANS) method for thyroidectomy without gas insufflation approach did not increase the surgical complexity compared with the transoral vestibular three-incision thyroidectomy and the trans-areolar thyroidectomy. LEVEL OF EVIDENCE: 3 Laryngoscope, 2023.

Incidence neurosensory deficit in mandibular fractures.

Sensory disturbances in the inferior alveolar nerve (IAN) prior to treatment can be attributed to various factors, including the site, type of fracture, and fracture displacement. Therefore, it is of interest to assess the incidence of inferior alveolar nerve injuries associated with mandibular fractures before and after surgical treatment. Group A consisted of patients with inferior alveolar nerve paresthesia before treatment, while Group B consisted of patients with inferior alveolar nerve paresthesia after treatment. A significant difference was observed between the two groups, with a p-value of 0.031 (p <0.05) with the overall incidence of IAN deficit was 57.33% before treatment and 61.33% after treatment. These findings highlight the importance of promptly identifying and managing IAN injuries to minimize long-term consequences.

Three-dimensional analysis of mandibular and mental canals corroborating with teeth and mental foramen by cone beam computed tomography.

BACKGROUND: This study aimed to analyse the 3D patterns of the mandibular and mental canals (MDC and MC) referring to the surrounding prominent surgical landmarks such as teeth and mental foramen by cone beam computed tomography (CBCT). METHODS: CBCT scans of 354 patients aged 18-67 years with mandibular first premolar to second molar were included and reconstructed 3-dimensionally (3D) by mimics. The parameters of MDC and MC were measured referring to teeth and mental foramen. RESULTS: From the first premolars to the second molars, the mandibular canals showed a trend of gradually closer to the cementoenamel junction (CEJ) of the adjacent teeth and farther away from the buccal cortical plate. The distance of the MDC with the root apexes (RA) was relatively constant from the first premolar to the first molar, but became much closer to the second molar. About 10.8% of the second molars had MDC-RA distances of shorter than 2 mm, and 1.34% even had the MDC superior to the RA. Moreover, the Type III of MC presented in 66.0% of the subjects and had a relatively longer length. Besides, the existence of Type I MC may be related to the MDC featuring with close distances to the RA and CEJ of the adjacent teeth. CONCLUSION: Dentists and surgeons should know the patterns of mandibular and mental canals. A better understanding of the MDC and MC and their relationship to local anatomical landmarks may facilitate the planning of surgeries and alert potential nerve injuries in the operative procedures.

Effects of RNA m6A writer METTL3 and hDPSCs on the peripheral nerve regeneration: In vitro and in vivo study.

PURPOSE: This study aimed to investigate whether RNA m6A participated in the differentiation and proliferation of dental pulp stem cells and improved peripheral nerve regeneration using a rat model of crushed mental nerve injury. MATERIALS AND METHODS: The components of RNA m6A were analyzed through qRT-PCR, while cell proliferation of different groups, including over-expression METTL3 (OE-METTL3) hDPSCs group, knock-down METTL3 (KD-METTL3) hDPSCs group and hDPSCs group in vitro, was clarified by MTT assay. Five groups were designed, namely, Control group, Sham group, hDPSCs group, OE-METTL3 group and KD-METTL3 group. After crushed right mental nerve injury, cells of different groups were transplanted into the lesion area (6 ul in volume). At one, two and three weeks later, histomorphometric analysis and sensory test were conducted in vivo. RESULTS: qRT-PCR results showed that "METTL3" was participated in the differentiation of dental pulp stem cells. There were differences (P < 0.05) between OE-METTL3 group and control group in MTT results in the third, fourth and sixth days. Moreover, the sensory test revealed significant differences (P < 0.05) in difference score and gap score between OE-METTL3 group and KD-METTL3 group in the first and third weeks. The axon counts and retrograde labeled neurons significantly increased in OE-METTL3 group compared with KD-METTL3 group. CONCLUSIONS: These results demonstrated that RNA m6A participated in the differentiation and proliferation of dental pulp stem cells, and that OE-METTL3 group exhibited the greater ability to improve peripheral nerve regeneration than KD-METTL3 group and hDPSCs group.

Resolution of Apical Periodontitis-induced Mental Nerve Paresthesia Through Nonsurgical Endodontic Retreatment: A Case Report.

Paresthesia is a potential consequence of unsuccessful root canal treatment. Persistent infection resulting in apical periodontitis may enlarge sufficiently to involve the mental neurovascular bundle. The case presented in this report was referred for endodontic evaluation with a chief complaint of discomfort on mastication and persistent numbness of the lower left lip. Clinical and radiographic evaluation revealed incomplete primary endodontic treatment of the left mandibular second premolar with complex internal anatomy. The untreated root canal system resulted in the progression of apical periodontitis involving the left mental neurovascular bundle as confirmed by cone-beam computed tomography imaging. Nonsurgical root canal retreatment was performed over 2 visits. At the 3-year follow-up visit, the paresthesia had resolved with return of normal sensation. Nonsurgical endodontic retreatment may be sufficient to allow healing of large periapical lesions and resolve complications including paresthesia without the need for surgical intervention.

The Temporary Mental Nerve Paresthesia as an Outcome of Dentigerous Cyst Removal during Preparation for Dental Implant Placement: A Case Report.

The usage of xenograft material is widely used in almost all oral cavity bone defects for regenerative and reconstructive purposes. The presented xenograft usage in the following care report enabled good bone defect healing and enabled the preservation of affected premolars. It is quite common to use any possible variations of bone materials to ensure bone defect improved healing. In some cases, the scope of surgeries requires the removal of each cyst within close proximity to various nerves and vessels. The inferior alveolar, infraorbital, lingual, and mental nerves are those most commonly adjacent to most operating sites in jaw bones. The usage of some additional materials such as collagen sponges, bone substitutes, resorbable membranes, or other additional materials are useful in each bone defect reconstruction but should be handled with care, as described in the following case. Before planning their usage, it is important to perform each surgery with close cone beam computed tomography imaging, which is very helpful to establish the scope of each lesion and the proximity of vital structures. There are a lot of factors that might influence any possible nerve damage, especially the different nerve anatomical variations. Even factors including the subperiosteal preparation and compression of adjacent tissues might influence later nerve function. When the lesion is expanding through the buccal cortical plate and when soft tissue fluctuation is present, some special care is needed. Similar to the presented case, a limitation in crushing, blowing, or any irritation of nerve fibers improves later postoperative outcomes. When the wound and surrounding tissues are handled with care, a limited possibility of any damage or paresthesia can occur. When the nerve itself is damaged or cut, loss of function can be permanent. Immediately after or even prophylactic prescription 1-2 days before the surgery of Vitamin B with NSAIDs (Non-steroidal anti-inflammatory drugs) (or other additional supplementary medicaments can improve nerve function in time. Possible nerve damage can be divided into many etiological factors. A quite different situation arises when the nerve is pulled in by the cyst growth into the cyst wall. The presented case report describes the outcomes of a cyst removal from the mandibular basis and treatment modalities.

Anatomical Study of the Communication Between the Mental Nerve and Marginal Mandibular Branch of the Facial Nerve.

Background Trigeminal-facial nerve communications have been recognized for over 100 years. More specifically, the mental nerve (MN) and marginal mandibular branch of the facial nerve (MMb) communication have been studied but the termination of these branches remains unclear. Therefore, we aim to classify the anatomical communication between the MN and MMb by its course. Methods Sixty sides from thirty adult cadaveric heads were dissected. The communicating branches were dissected and observed anatomically and histologically. Results Communication between the MN and MMb was found on all sides. Based on the course, the communication was classified into two types, superior and anterior. For the superior type, a small branch of the MN and MMb join and travel superiorly to reach the lower lip area. The communication was observed at the level of the mental foramen or above it. For the anterior type, a small branch of the MN and MMb join and travel anteriorly to reach the chin area. The termination was either in the subcutaneous tissue of the chin or in the mentalis. This communication was observed below the mental foramen. Histological observation revealed that these communications contained two or more perineuria. Conclusions Although the function of such neural communications is still unclear, this study helps better understand the anatomical variants of these unions and provides a novel classification system.

Mental nerve shielding from possible injury during mandibular surgical procedures: technical note.

Injuries to the mental nerve are not an uncommon complication in maxillofacial surgeries. Manipulation close to the mental nerve poses a great risk of nerve injury from drills, bone cutting and trimming burs, and oscillating/reciprocating saws. Nerve injuries can be painful and affect the patient's quality of life. The accompanying complication of the nerve injury depends on the severity of the damage inflicted and can range from transient hypoesthesia to neuropathic pain or trigeminal neuralgia. It is considered that direct injury to the nerve may lead to permanent damage and more severe postoperative clinical symptoms than indirect injuries caused by nerve stretching or during endosteal implant fixation. This technical note describes a technique for shielding the mental nerve and protecting it from rotary drill injury during mandibular inferior border recontouring, orthognathic surgeries, and mandibular body fracture fixation.

Effects of sagittal split osteotomy on brainstem reflexes.

OBJECTIVES: This prospective study was designed to assess whether patients with skeletal deformities show characteristic masseter inhibitory reflex (MIR) and blink reflex (BR) patterns. A secondary aim was to investigate whether these reflexes change following bilateral sagittal split osteotomy (BSSO). MATERIALS AND METHODS: Fourteen consecutive patients who underwent single-jaw BSSO and 14 class I subjects who constituted the control group were enrolled into the study. MIR and BR, obtained by the stimulation of supraorbital (SBR) and mental nerves (MBR), were electrophysiologically recorded. Sensory impairment in the mental nerve distribution was clinically tested. Three evaluation periods were specified as immediately before (T0), 1 month (T1) and 6 months (T2) after surgery. RESULTS: MIR early silent period duration was significantly shorter in the patients at T0 (p < 0.001). Sensory deficits developed on 23 sides after BSSO, of which, 17 recovered after 6 months. At T1, MBR was inelicitable bilaterally in 3 patients and unilaterally in 2 patients. These responses were still unrecordable bilaterally in 1 patient, and unilaterally in 4 patients at T2. MIR were unrecordable on 18 sides at T1 and recovered on 11 sides at T2. There were no parallels between the clinical sensory deficits and the abnormal results of the reflexes. CONCLUSIONS: Shorter MIR in patients with dentofacial abnormalities may be a reflection of an adapted trigeminal reflex mechanism. Although MBR and MIR abnormalities do not develop parallel to the clinical sensory deficits, their course might provide insights into the disturbed trigeminal reflex pathways.