Parestesia do nervo alveolar inferior decorrente de procedimentos cirúrgicos e suas formas de tratamentos / Paresthesi of the lower alveolar nerve resulting from surgical procedures and its forms of treatment

Nas cirurgias odontológicas é possível que ocorra alguns acidentes ou complicações que podem interferir no dia a dia do paciente. A lesão do nervo alveolar inferior é uma complicação decorrente de cirurgias orais que podem causar um distúrbio de sensibilidade transitória ou persistente, na região do lábio inferior e na região delimitada do forame mentoniano e hemi-arco da mucosa. O diagnóstico da parestesia pode ser feito através de testes mecanoceptivos e nocioceptivos em que o profissional escolherá para qual melhor se adapte no paciente. O objetivo do presente trabalho foi abordar por meio de uma revisão de literatura as formas de diagnóstico e tratamento da parestesia do nervo alveolar inferior decorrentes de cirurgias orais. As bases de dados utilizadas para confecção desta revisão são encontradas nas bibliotecas virtuais eletrônicas: BVS (Biblioteca Virtual em Saúde), LILACS (Literatura Latino-Americana e do Caribe em Ciências da Saúde) e Pubmed. Como critério de inclusão foram selecionados artigos publicados de 2012 a 2022 em língua inglesa, portuguesa e espanhola. Após a leitura do título e resumo dos resultados da pesquisa e aplicação dos critérios de inclusão e exclusão dentre eles foram excluídos 883, pois não se enquadravam no nosso critério de inclusão. No final, foram selecionados 13 estudos por meio de base de dados, que serviram de base para esta revisão. Concluímos que as formas de tratamento para a parestesia na literatura, são um pouco escassas e conflitantes, mas relata que o uso da laserterapia e acupuntura tem sido uma forma de tratamento com um bom índice de sucesso, e para os casos que não sejam suficientes tais tratamentos, pode-se optar por uma cirurgia(AU)

In dental surgeries it is possible to have some accidents or complications that can interfere with the patient's day. Injury to the inferior alveolar nerve is a complication resulting from oral surgeries that can cause a disturbance of sensitivity that can be transient or persistent in the region of the lower lip and in the delimited region of the mental foramen and hemiarch of the mucosa. The diagnosis of paresthesia can be made through mechanoceptive and nocioceptive tests that the professional will choose, which best suits the patient. The objective of the present work is to approach, through a literature review, the forms of diagnosis and treatment aimed at inferior alveolar nerve paresthesia resulting from oral surgeries. The databases used for this review are found in the virtual electronic libraries: VHL (Virtual Health Library), LILACS (Latin American and Caribbean Literature on Health Sciences) and Pubmed. As inclusion criteria, articles published from 2012 to 2022 in English, Portuguese and Spanish were selected. After reading the title and summary of the research results and applying the inclusion and exclusion criteria, 883 were excluded, as they did not meet our inclusion criteria. In the end, 13 studies were selected from the database, which served as the basis for this review. We conclude that the forms of treatment for paresthesia in the literature are a little scarce and conflicting, but it reports that the use of laser therapy and acupuncture has been a form of treatment with a good success rate, and for cases that are not enough, such treatments, one can opt for surgery(AU)

Promotion effect of TGF-β-Zfp423-ApoD pathway on lip sensory recovery after nerve sacrifice caused by nerve collateral compensation / 国际口腔科学杂志·英文版

Resection of oral and maxillofacial tumors is often accompanied by the inferior alveolar nerve neurectomy, resulting in abnormal sensation in lower lip. It is generally believed that spontaneous sensory recovery in this nerve injury is difficult. However, during our follow-up, patients with inferior alveolar nerve sacrifice showed different degrees of lower lip sensory recovery. In this study, a prospective cohort study was conducted to demonstrate this phenomenon and analyze the factors influencing sensory recovery. A mental nerve transection model of Thy1-YFP mice and tissue clearing technique were used to explore possible mechanisms in this process. Gene silencing and overexpression experiments were then conducted to detect the changes in cell morphology and molecular markers. In our follow-up, 75% of patients with unilateral inferior alveolar nerve neurectomy had complete sensory recovery of the lower lip 12 months postoperatively. Patients with younger age, malignant tumors, and preservation of ipsilateral buccal and lingual nerves had a shorter recovery time. The buccal nerve collateral sprouting compensation was observed in the lower lip tissue of Thy1-YFP mice. ApoD was demonstrated to be involved in axon growth and peripheral nerve sensory recovery in the animal model. TGF-β inhibited the expression of STAT3 and the transcription of ApoD in Schwann cells through Zfp423. Overall, after sacrificing the inferior alveolar nerve, the collateral compensation of the ipsilateral buccal nerve could innervate the sensation. And this process was regulated by TGF-β-Zfp423-ApoD pathway.

Risco de lesão do ramo mandibular do nervo trigêmeo na fratura de mandíbula: um estudo anatômico / Risk of injury to the mandibular branch of the trigemal nerve in jaw fracture: an anatomical study

O nervo mandibular V3 é a terceira divisão do nervo trigêmeo, apresenta fibras motoras e sensitivas, sendo a ramificação mista deste nervo. Seus ramos eferentes são responsáveis pela motricidade dos músculos mastigatórios, inerva os músculos milo-hióideo, ventre anterior do digástrico, tensor do véu palatino e tensor do tímpano. Suas fibras aferentes são responsáveis pela sensibilidade da região inferior da face e cavidade oral, dentes inferiores, parte da língua e propriocepção da cápsula da articulação temporomandibular ATM. O objetivo deste estudo é explanar as possíveis lesões no nervo mandibular, suas ramificações e estruturas adjacentes no caso de fraturas na mandíbula, colaborando com informações detalhadas para posterior estudo de acadêmicos e cirurgiões dentistas. Foi realizada uma pesquisa de campo, exploratória e descritiva, com abordagem quanti-qualitativa, para descrição e análise do trajeto do V3 até a sua chegada no osso mandibular, assim como de estruturas que compõem a topografia adjacente a mesma utilizando uma hemiface intacta de um cadáver do sexo masculino no Laboratório de Anatomia Humana das Faculdades Nova Esperança, na cidade de João Pessoa. Devido à proximidade do nervo mandibular com o processo coronoide, fraturas nesta parte do osso mandíbula, podem ocasionar lesões no V3, além de traumas no osso temporal, e consequentemente de todo o gânglio trigeminal. Além destas, estruturas adjacentes como a glândula parótida, artérias maxilar e facial, ATM, e os nervos alveolar inferior, mentual e lingual, podem ser lesionadas em uma fratura mandibular. As lesões nestes nervos, podem resultar em redução grave da qualidade de vida e dor crônica, gerando desconfortos para o paciente. Diante do exposto fica evidente a importância de conhecer a anatomia topográfica da mandíbula e suas estruturas vasculonervosas, seu trajeto e a localização. Houve dificuldade na discussão devido à escassez da literatura em relação à temática proposta. Dessa forma, é necessário motivar novos estudos sobre a temática a fim de ampliar o conhecimento dos profissionais de saúde e estimular novas técnicas para diagnóstico precoce e melhorar os resultados terapêuticos, impactando positivamente na sobrevida de pacientes com fraturas de mandibulares(AU)

The mandibular nerve V3 is the third division of the trigeminal nerve, has motor and sensory fibers, being the mixed branch of this nerve. Its efferent branches are responsible for the motricity of the masticatory muscles, innervating the mylohyoid muscles, anterior belly of the digastric, soft palate tensor and tympanic tensor. Its afferent fibers are responsible for the sensitivity of the lower face and oral cavity, lower teeth, part of the tongue and proprioception of the capsule of the temporomandibular joint TMJ. The aim of this study is to explain the possible injuries to the mandibular nerve, its ramifications and adjacent structures in the case of mandible fractures, collaborating with detailed information for further study by academics and dentists. A field research, exploratory and descriptive, with a quantitative-qualitative approach, was carried out to describe and analyze the path of the V3 until its arrival in the mandibular bone, as well as structures that make up the topography adjacent to it using na intact hemiface of a male cadaver at the Human Anatomy Laboratory of Faculdades Nova Esperança, in João Pessoa city. Due to the proximity of the mandibular nerve with the coronoid process, fractures in this part of the mandible bone can cause injuries to the V3, in addition to trauma to the temporal bone, and consequently to the entire trigeminal ganglion. In addition to these, adjacent structures such as the parotid gland, maxillary and facial arteries, TMJ, and the inferior alveolar, mental and lingual nerves can be injured in a mandibular fracture. Damage to these nerves can result in severely reduced quality of life and chronic pain, causing discomfort for the patient. Given the above, the importance of knowing the topographic anatomy of the mandible and its vascular-nervous structures, its path and location is evident. There was difficulty in the discussion due to the scarcity of literature regarding the proposed theme. Thus, it is necessary to motivate further studies on the subject in order to expand the knowledge of health professionals and encourage new techniques for early diagnosis and improve therapeutic results, positively impacting the survival of patients with mandibular fractures(AU)

Changes in somatosensory perception induced by trigeminal injury after Maxillofacial Surgical Procedures / Cambios en la percepción somatosensorial inducidos por lesiones trigeminales causadas por procedimientos quirúrgicos maxilofaciales

Abstract Evidence has been reported that shows that somatosensory perception can be altered by a trigeminal injury resulting from maxillofacial surgical procedures. However, the surgical procedures that most frequently cause trigeminal lesions and the risk factors are unknown. In the same way, there is little information on what has been determined in preclinical models of trigeminal injury. This article integrates relevant information on trigeminal injury from both clinical findings and primary basic science studies. This review shows that the age and complexity of surgical procedures are essential to induce orofacial sensory alterations.

Resumen Se han reportado evidencias que demuestran que la percepción somatosensorial puede ser alterada por la lesión trigeminal producto de procedimientos quirúrgicos maxilofaciales. Sin embargo, se desconoce cuáles son los procedimientos quirúrgicos que más frecuentemente producen lesiones trigeminales, y los factores de riesgo. De la misma forma hay poca información sobre lo que se ha determinado en modelos preclínicos de lesión trigeminal. El objetivo de este artículo es integrar información relevante sobre la lesión trigeminal desde los hallazgos clínicos como los principales estudios de ciencia básica. Esta revisión demuestra que la edad y el tipo de procedimiento son fundamentales para inducir alteraciones sensoriales orofaciales, así como los procesos neurobiológicos que subyacen a estos padecimientos.

Evaluating the risk factors of inferior alveolar nerve injury following removal of the mandibular third molars / 中华口腔医学杂志

Objective: To evaluate the risk factors of inferior alveolar nerve injury (IANI) after surgical removal of the mandibular third molars (M3) and present a new risk scoring system to predict the probability of IANI. Methods: Patients who underwent extraction of M3 in the Stomatology Hospital, Zhejiang University School of Medicine from April 2017 to December 2019 were involved. The investigators enrolled a sample composed of 949 mandibular third molars. Prediction model was used for univariate and multivariate analysis of gender, age, M3, inferior alveolar canal (IAC), and the contact between M3 and IAC, to assess the risk factors of IANI. Combined with the risk factors determined by the outcomes of prediction model, the risk scoring system was constructed. The diagnostic performance of each cut-off score was examined to conduct a risk stratification of IANI risk scores. The predictive ability and reliability of the model were evaluated. Results: In prediction model, twenty nine cases (4.4%, 29/664) experienced postoperative IANI. Number of root (P<0.01), depth of impaction (P<0.05), contact between M3 and IAC (P<0.01) and their contact position (P<0.05) were statistically significant as contributing risk factors of IANI. Specifically, the incidence of temporary IANI was higher in those who aged under 25 years (P<0.001), while female suffer more permanent injury (P<0.05). Based on the IANI risk scoring system, patients were stratified into low-risk, middle-risk and high-risk groups at cutoff scores of 3 and 4. The area under the receiver operator characteristic curve of the risk scoring system were 0.81 [95%CI (0.70-0.90), P=0.002] and 0.80 [95%CI (0.68-0.92), P=0.007] towards good discrimination. Conclusions: Age, gender, number of root, depth of impaction, and contact between M3 and IAC were risk factors of IANI. IANI risk scoring system might help in preoperative assessment, recognition of high-risk cases and decision-making to reduce IANI.

Role of neuron and non-neuronal cell communication in persistent orofacial pain

It is well known that trigeminal nerve injury causes hyperexcitability in trigeminal ganglion neurons, which become sensitized. Long after trigeminal nerve damage, trigeminal spinal subnucleus caudalis and upper cervical spinal cord (C1/C2) nociceptive neurons become hyperactive and are sensitized, resulting in persistent orofacial pain. Communication between neurons and non-neuronal cells is believed to be involved in these mechanisms. In this article, the authors highlight several lines of evidence that neuron-glial cell and neuron macrophage communication have essential roles in persistent orofacial pain mechanisms associated with trigeminal nerve injury and/or orofacial inflammation.

Management and prevention of third molar surgery-related trigeminal nerve injury: time for a rethink

Trigeminal nerve injury as a consequence of lower third molar surgery is a notorious complication and may affect the patient in long term. Inferior alveolar nerve (IAN) and lingual nerve (LN) injury result in different degree of neurosensory deficit and also other neurological symptoms. The long term effects may include persistent sensory loss, chronic pain and depression. It is crucial to understand the pathophysiology of the nerve injury from lower third molar surgery. Surgery remains the most promising treatment in moderate-to-severe nerve injuries. There are limitations in the current treatment methods and full recovery is not commonly achievable. It is better to prevent nerve injury than to treat with unpredictable results. Coronectomy has been proved to be effective in reducing IAN injury and carries minimal long-term morbidity. New technologies, like the roles of erythropoietin and stem cell therapy, are being investigated for neuroprotection and neural regeneration. Breakthroughs in basic and translational research are required to improve the clinical outcomes of the current treatment modalities of third molar surgery-related nerve injury.

Trigeminal somatosensory evoked potential test as an evaluation tool for infraorbital nerve damage

BACKGROUND: Neurosensory changes are frequently observed in the patients with mid-face fractures, and these symptoms are often caused by infraorbital nerve (ION) damage. Although ION damage is a relatively common phenomenon, there are no established and objective methods to evaluate it. The aim of this study was to test whether trigeminal somatosensory evoked potential (TSEP) could be used as a prognostic predictor of ION damage and TSEP testing was an objective method to evaluate ION injury. METHODS: In this prospective TSEP study, 48 patients with unilateral mid-face fracture (only unilateral blow out fracture and unilateral zygomaticomaxillary fracture were included) and potential ION damages were enrolled. Both sides of the face were examined with TSEP and the non-traumatized side of the face was used as control. We calculated the latency difference between the affected and the unaffected sides. RESULTS: Twenty-four patients recovered within 3 months, and 21 patients took more than 3 months to recover. The average latency difference between the affected side and unaffected side was 1.4 and 4.1 ms for the group that recovered within 3 months and the group that recovered after 3 months, respectively. CONCLUSION: Patients who suffered ION damage showed prolonged latency when examined using the TSEP test. TSEP is an effective tool for evaluation of nerve injury and predicting the recovery of patients with ION damage.

Multidimensional study of orofacial chronic neuropathic pain: an experimental study in rats

Orofacial neuropathic chronic pain (NCP) is frequently attributed to lesions caused by orofacial surgeries and dental treatments. there are many experimental models available to study orofacial NCP, however, many are extremely painful for the animal due to the amplitude of the innervated region. a previously proposed mental nerve constriction model, mNC, was used in this project. forty wistar rats were randomly divided into two groups: one group included rats with mNC (n=20), and another rats with sham lesions (n=20). through the use of the fixed ratio program and the progressive program, a decrease of motivation for a sweet substance, caused by the lesion, was evaluated. the possibility of alterations in cognitive learning and adaptation abilities was also assessed using the go/no-go behavioral task. the mNC group showed low induced and spontaneously evoked pain responses, as well as a decrease in the motivation for sucrose, a sign of anhedonia. this decrease does not depend on taste processing. finally, although no alterations in the learning-memory process were observed, the mNC group did show alterations when adapting to a new rule.

Morphometric relationships between the mandibular canal and the molar teeth: a tomographic analysis report / Relaciones morfométricas entre el canal mandibular y los dientes molares: reporte de un análisis tomográfico

Some dental treatments that are performed in the mandibular teeth involve manipulation of anatomical structures near the dental periapex, so it is likely to cause nerve damage due to the proximity of the inferior alveolar nerve with the apices of the mandibular teeth, mainly in the molar area. The aim of this study was to determine through Computed Tomography (CT) scan the existing distance between the mandibular canal and the anatomical structures adjacent to its path which will help to reduce the risk of injury to the inferior alveolar nerve during the different dental treatments developed in this zone. A cross-sectional study was performed where the study population consisted of 50 patients of both sexes, between 20 and 30 years with a full dentition mandible. Patients underwent a CT study of the mandible with coronal planes at 1.5 mm, the right side and the left side of each jaw were considered for the analysis and millimetric measuring was held of the distances of the mandibular canal (MC) from different anatomical structures. Subsequently, a statistical analysis was performed to obtain the mean and standard deviation of the distances between the mandibular canal and some adjacent anatomical structures. The distance from the alveolar nerve canal to the apex of the lower third molar in average was 1.49 mm on the right side and 1.69 mm on the left side, the distance between the mandibular canal and lingual cortical at the lower first molar level on average was 3.54 mm on the right side and 4.02 mm on the left side and the distance between the lingual cortical at the second molar level was on average 2.86 mm on the right side and 3.6 mm on the left side.

Algunos tratamientos dentales que se realizan en los dientes mandibulares implican la manipulación de estructuras anatómicas cercanas al periapice dental, por lo que existe la probabilidad de causar lesiones nerviosas debido a la cercanía del canal mandibular con los ápices de los dientes mandibulares, principalmente los molares. El objetivo de este estudio fue determinar a través de tomografía computarizada la distancia existente entre el canal mandibular a las estructuras anatómicas adyacentes a su trayecto lo que ayudará a disminuir el riesgo de lesiones del nervio alveolar inferior durante los diferentes tratamientos dentales desarrollados en esta zona. Se realizó un estudio transversal en donde la población de estudio estuvo compuesta por 50 pacientes de ambos sexos, entre 20 a 30 años con dentición completa en mandíbula. A los pacientes se les realizó un estudio de Tomografía Computarizada (TC) en mandíbula con cortes coronales a 1.5mm, se consideraron para el análisis el lado derecho y el lado izquierdo de cada mandíbula, y se realizó la medición milimétrica de las distancias que existen desde el CNAI a diferentes estructuras anatómicas. Posteriormente, se realizó un análisis estadístico para obtener Medias y Desviación Estándar de las distancias que existen entre el canal mandibular y algunas estructuras anatómicas adyacentes. La distancia del canal mandibular al ápice del tercer molar inferior en promedio fue de 1,49 mm del lado derecho y de 1,69 mm del lado izquierdo,la distancia entre el canal mandibular y la cortical lingual a nivel del primer molar inferior en promedio fue de 3,54 mm del lado derecho y de 4,02 mm del lado izquierdo y la distancia entre la cortical lingual a nivel del segundo molar fue en promedio de 2,86 mm del lado derecho y de 3,6 mm del lado izquierdo.

Coronectomía en terceros molares mandibulares como alternativa de tratamiento seguro en la prevención del daño al nervio alveolar inferior: revisión bibliográfica y reporte de 30 casos / Coronectomy in third mandibular molars as an alternative treatment to prevent damage to the inferior alveolar nerve: bibliographic review and 30 cases report

La lesión del nervio alveolar inferior (NAI) al extraer los terceros molares mandibulares esa menudo causada por la íntima relación entre el nervio y las raíces dentarias. La técnica de coronectomía ola retención intencionada de raíz, podría mitigar este problema. Treinta pacientes fueron sometidos a coronectomia en 30 terceros molares mandibulares con seguimiento de al menos 6 meses. Todos los pacientes fueron radiografiados antes de la intervención, inmediatamente después de la operación, y después de 6meses. La técnica se realizó con protección del nervio lingual como parte del procedimiento quirúrgico. Todas las raíces quedaron al menos 3 mm por debajo de las tablas óseas bucal y lingual. No hubo ningún caso de daño del NAI. Hubo un caso de afectación transitoria del nervio lingual, probablemente por el uso del retractor lingual. Un paciente requirió la retirada posterior de las raíces de los terceros molares, debido a la falta cicatrización, y otro paciente requirió la retirada posterior de una raíz a causa de migración posterior ala superficie. La migración de las raíces se observó en aproximadamente el 30 % de los pacientes durante un período de 6 meses. La coronectomia parece ser una técnica viable en aquellos casos en que la extracción completa del diente podría poner al NAI en un riesgo considerable de daño. La técnica parece estar asociada con una baja incidencia de complicaciones, pero la migración posterior de las raíces puede ser un problema en el largo plazo.

The inferior alveolar nerve (IAN) injury to remove the third molars is often caused by the intimate relationship between the nerve and the roots of the teeth. Coronectomy technique or intentional root retention, may minimize this problem. Thirty patients underwent coronectomy in 30 third molars with follow up of at least 6 months. Coronectomy technique deliberately protected the lingual nerve as part of the surgical procedure. All roots were at least 3 mm below the buccal and lingual bony walls. All patients were radiographed preoperatively, immediately postoperatively, and after 6 months. There were no cases of IAN damage involved in this study of 30 patients who underwent 30 coronectomies. There was one case of transient lingual nerve involvement, probably by the use of lingual retractor. One patient required subsequent removal of the roots of both lower third molars, due to lack of healing, and one patient required subsequent removal of a root cause of migration back to the surface. migration of the roots was observed in approximately 30 percent of patients during a period of six months. Coronectomy seems to be a viable technique in those cases where the removal of all tooth could put the IAN at considerable risk of damage. The technique appears to be associated with a low incidence of complications, but the subsequent migration of the roots can be a problem in the long term.

Painful Horner syndrome after thyroidectomy: A case report

Horner syndrome is characterized by miosis, partial blepharoptosis and anhidrosis on the affected side of the face. This syndrome develops when the oculosympathetic nerve pathways to the eye and face are interrupted by various causes such as tumor in the brain, intrathoracic region or neck, surgery, drugs, trauma, carotid artery dissection, and others. It is referred to as painful Horner syndrome when Horner syndrome is accompanied by hemifacial pain. Pain is probably related to trigeminal nerve injury. Horner syndrome is a rare complication of thyroidectomy. Here, we report the case of a patient who experienced ipsilateral painful Horner syndrome after total thyroidectomy and unilateral neck dissection for thyroid cancer.

Complicaciones en cirugía ortognática: conceptos actuales y revisión de la literatura / Complications in orthognathic surgery: current concepts and review of the literature

La cirugía ortognática es el tratamiento de elección para corregir deformidades dentofaciales congénitas o adquiridas en menor cantidad de casos, estas técnicas pueden ser aplicadas en la resección de tumores y apnea del sueño. Usualmente se lleva a cabo entre la segunda y tercera década de vida. Dentro de los benefi cios que se obtienen se incluyen una mejor función masticatoria, resultados estables en discrepancias dentofaciales severas y un mejor aspecto estético facial. Sin embargo, aun el cirujano más experimentado puede enfrentar complicaciones, entre las que destacan las vasculares, técnicas, nerviosas, periodontales, infecciosas, oftálmicas, de oclusión, psicológicas y necrosis ósea. Algu-nas de estas complicaciones pueden discutirse en detalle con el paciente antes del procedimiento. A pesar de lo anterior, el tratamiento de cirugía ortognática puede ser considerado como un procedimiento seguro. Las complicaciones se pueden dividir en preoperatorias, transoperatorias y postoperatorias, teniendo en las dos últimas una mayor incidencia.

Orthognathic surgery is the treatment of choice for the correction of congenital or acquired dentofacial deformities; in a minority of cases, the techniques involved can be applied to tumor resection and to treat sleep apnea. This type of surgery is usually performed between the second and third decades of life. The benefi ts obtained include a better chewing function, stable results in severe dentofacial anomalies, and improved facial aesthetics. However, even the most experienced surgeon can encounter a range of issues, most notably vascular, technical, ner-vous, periodontal, infectious, ophthalmic, psychological, those related to occlusion, and bone necrosis. Some of these can be discussed in detail with the patient prior to the procedure. Nevertheless, orthognathic surgery treatment can be considered a safe procedure. Complications can be classifi ed into three types: preoperative, intraoperative, and postoperative, the latter two being the most common.

Correlation between radiographic signs of third molar proximity with inferior alveolar nerve and postoperative occurrence of neurosensory disorders: A prospective, double-blind study

PURPOSE: To evaluate the interference of radiographic factors in the appearance of sensory deficit related to inferior alveolar nerve (IAN) after third molars (3Ms) removal. METHODS: A prospective, double-blind, observational, unicentric study was performed with 126 patients submitted to a surgical procedure of lower 3Ms removal in the period from March to October/2011. Collected data included gender, age, eruption stage of 3Ms, position/angle of 3Ms (Pell-Gregory and Winter classifications, respectively), presence/absence of radiographic signs of 3Ms proximity with the inferior alveolar canal and surgical technique. Occurrence evaluation of the IAN injury was performed on the seventh postoperative day through pin-prick, two-point discrimination and brush directional stroke tests. RESULTS: Predominant radiographic signs were: narrowing of the inferior alveolar canal (68.25%), darkening of root (46.82%) and diversion of the canal (31%). None of the patients presented sensory loss. Sixty-one (48.41%) of the cases had at least one or two radiographic signs of proximity with NAI. Forty-seven (37.3%) had 3 or more signs, and 18 (14.29%) did not have any radiographic signs of proximity to mandibular canal. CONCLUSION: There was not a positive correlation between presence of radiographic signs of 3Ms with IAN proximity and postoperative neurosensory disorders occurrence.

Quantitative sensory testing in trigeminal traumatic neuropathic pain and persistent idiopathic facial pain / Teste sensitivo quantitativo em dor neuropática trigeminal pós-traumática e dor facial idiopática persistente

The objective of this article was to investigate, with a systematic protocol of quantitative sensory testing, patients with persistent idiopathic facial pain (PIFP) and others with trigeminal traumatic neuropathic pain (TTN) compared to controls. Thirty patients with PIFP, 19 with TTN, and 30 controls were evaluated on subjective numbness and dysesthesia and with a systematic protocol of quantitative sensory testing for thermal evaluation (cold and warm), mechanical detection (touch and pinpricks for mechanical pain), superficial pain thresholds, and corneal reflex. We found that PIFP and TTN had numbness and dysesthesia higher than controls (p<0.001 and p=0.003), and that in both of them mechanical pain by pinpricks detection was abnormal intra and extra orally at the mandibular branch (p<0.001). Cold, warm, and tactile detections and pain thresholds were similar among the groups. Corneal reflex was abnormal in TTN (p=0.005). This study supports neuropathic mechanisms involving pain processing in PIFP and that the criterion on absence of sensorial variations in PIFP should be revised.

O objetivo deste artigo foi investigar, com um protocolo sistemático de testes sensitivos quantitativos, pacientes com dor facial idiopática persistente (DFIP) e outros com dor neuropática trigeminal traumática (DNTT) comparado aos controles. Trinta pacientes com DFIP, 19 com DNTT e 30 controles foram avaliados quanto à dormência e à disestesia subjetiva e por meio de um protocolo sistemático de testes sensitivos quantitativos, que incluiu avaliação térmica (frio e quente), detecção mecânica (táctil e alfinetes), limites de dor superficial e reflexo córneo-palpebral. Foi observado que os pacientes apresentaram mais dormência e disestesia do que os controles (p<0,001 e p=0,003), além de mais anormalidades intra e extraorais no ramo mandibular (p<0,001). As alterações de calor, frio, dor e tato foram semelhantes entre os grupos. O reflexo córneo-palpebral foi anormal somente no grupo com DNTT (p=0,005). Este estudo suporta mecanismos de dor neuropática envolvidos no processamento da DFIP, e o critério de ausência de variações sensoriais nesta deve ser revisto.

Altered thermal sensitivity in facial skin in chronic whiplash-associated disorders / 国际口腔科学杂志·英文版

There is a close functional relationship between the jaw and neck regions and it has been suggested that trigeminal sensory impairment can follow whiplash injury. Inclusion of manageable routines for valid assessment of the facial sensory capacity is thus needed for comprehensive evaluations of patients exposed to such trauma. The present study investigated facial thermal thresholds in patients with chronic whiplash-associated disorders (WADs) with both a qualitative method and quantitative sensory testing (QST). Ten women with pain and dysfunction following a whiplash injury were compared to 10 healthy age-matched women. Thermal detection thresholds were assessed by qualitative chair-side testing and by QST according to the method-of-limits. Seven test sites in the facial skin (overlying each trigeminal branch bilaterally, and the midpoint of the chin) were examined. The detection warm and cold thresholds were defined as the mean values of 10 individual thresholds. For the WAD patients, the qualitative assessment demonstrated both reduced and increased sensitivity compared to the healthy, whereas QST systematically showed significantly higher detection thresholds (i.e., decreased sensitivity) for both cold and warm stimuli. For the individuals who were assessed as having increased sensitivity in the qualitative assessment, the QST displayed either normal or higher thresholds, i.e., decreased sensitivity. The results suggest that QST is more sensitive for detecting thermal sensory disturbances in the face than a qualitative method. The impaired thermal sensitivity among the patients corroborates the notion of altered thermal detection capacity induced by WAD-related pain.

Distribution of the lingual foramina in mandibular cortical bone in Koreans

OBJECTIVES: The interforminal region, between the mandibular foramen, is known as a relatively safe area that is free of anatomic structures, such as inferior alveolar nerve, submandibular fossa, and lingual side of the mandible is occasionally neglected for its low clinical importance. Even in the case of a severely constricted alveolus, perforation of the lingual cortical bone had been intended. However, anterior extension of the inferior alveolar canal, important anatomic structure, such as concavity of lingual bone, lingual foramina, and lingual canal, has recently been reported through various studies, and untypical bleeding by perforation of the lingual plate on implantation has also been reported. Therefore, in this study, we performed radiographic and statistical analysis on distribution and appearance frequencies of the lingual foramina that causes perforation of the mandibular lingual cortical bone to prevent complications, such as untypical bleeding, during surgical procedure. MATERIALS AND METHODS: We measured the horizontal length from a midline of the mandible to the lingual foramina, as well as the horizontal length from the alveolar crest to the lingual foramina and from the lingual foramina to the mandibular border by multi-detector computed tomography of 187 patients, who visited Dankook University Dental Hospital for various reasons from January 1, 2008 to August 31, 2012. RESULTS: From a total of 187 human mandibles, 110 (58.8%) mandibles had lingual foramina; 39 (20.9%) had bilateral lingual foramen; 34 (18.2%) had the only left lingual foramen; and 37 (19.8%) had the only right lingual foramen. CONCLUSION: When there is consistent bleeding during a surgical procedure, clinicians must consider damages on the branches of the sublingual artery, which penetrate the lingual foramina. Also, when there is a lingual foramina larger than 1 mm in diameter on a pre-implantation computed tomography, clinicians must beware of vessel damage. In order to prevent these complications and progress with a safe surgical procedure, a thorough radiographic examination before the surgery is indispensable. Further, clinicians should retract lingual flap definitely to confirm the shape of the lingual bone and existence of the lingual foramina.

Remoción de terceros molares mandibulares con asistencia endoscópica: nota técnica de un nuevo procedimiento quirúrgico para prevenir lesiones del NAI y formación de defectos óseos / Removal of mandibular third molars with endoscopic approach. Technical note of a new surgical procedure to avoid IAN damage and bone defect formation

La variada posición anatómica de los terceros molares mandibulares presenta importantes desafíos asociados a su profundidad y grado de inclinación. Las complicaciones más habituales del procedimiento quirúrgico convencional de extracción se relacionan con la extensa osteotomía y poca visualización del sitio quirúrgico, que pueden generar consecuencias post-quirúrgicas como inflamación, dolor, trismus, lesiones reversibles e irreversibles del nervio alveolar inferior (NAI) o nervio lingual, riesgo de fractura y formación de defectos periodontales del segundo molar. La implementación de soportes rígidos en la óptica endoscópica ha permitido utilizar esta tecnología para realizar abordajes mínimamente invasivos para remover terceros molares mediante accesos flapless con una mínima osteotomía de la zona oclusal, conservando la pared bucal y lingual a través de la visualización directa y magnificada del sitio quirúrgico, adaptable a los movimientos del paciente durante la intervención. En este reporte se presenta un nuevo procedimiento quirúrgico mínimamente invasivo a través de asistencia endoscópica para la conservación ósea en la remoción de terceros molares mandibulares con riesgo de lesión del nervio alveolar inferior.

Anatomic variability of the position of mandibular third molars represents significant challenges associated with its depth and angulation. The most common complications of conventional surgical procedure are related to extensive osteotomy and poor visualization, which can cause postsurgical effects such as inflammation, pain, trismus, reversible and irreversible lesions of the inferior alveolar nerve (IAN) or lingual nerve, fracture risk and formation of a deep periodontal defect on the distal aspect of the second molar. The implementation of rigid endoscopy in optics has allowed to use this technology via a minimally invasive approach to remove third molars by a minimally occlusal flapless ostectomy, preserving the buccal and lingual walls through direct and magnified visualization of the surgical site, adaptable to the patient’s movements during the surgery. In this report, we present a new and minimally invasive procedure through endoscopic assistance for bone conservation in the removal of third molars at risk of inferior alveolar nerve injury.

Displacement of endodontic instruments in inferior alveolar canal.

Endodontic instrument breakage is a common occurrence during root canal treatment but the displacement of the separated instrument into the inferior alveolar canal is rare and has never been reported. We hereby present an unusual case of displacement of a separated instrument in the inferior alveolar canal and its retrieval by a simple technique.