OBJECTIVE: 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.
CONCLUSIONS: 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.

Numerous procedures can potentially injure the inferior alveolar nerve during oral and maxillofacial surgery, eventually causing loss or alteration of local sensitivity. When its total rupture occurs, a conduit, such as an autogenous graft, can be used to join it. Due to the morbidity resulting from this technique, alternative forms of sensorineural repair have been investigated. This systematic review includes an electronic search of PubMed, Embase, LILACS, and Web of Science databases, in addition to a grey literature and manual search. Article selection was performed by two independent researchers following a predetermined inclusion criterion: human studies evaluating the regression of sensorineural disorders after any form of grafting (autogenous, allogeneic, and synthetic). Of the 789 studies, 648 were analysed. Only 11 articles met the eligibility criteria. After analysing the results, it was noted that regaining normal sensitivity was uncommon, but the majority of reconstructed nerves recovered their protective abilities. Allografts showed success rates similar to autogenous grafts, making them a viable alternative. However, clinical trials are still needed to provide solid evidence. Prognosis for sensory recovery was impacted by grafting time and patient age.

Inferior alveolar nerve (IAN) lateralization (IANL) or transposition (IANT) are both techniques allowing for dental implant placement in posterior atrophic mandibles. The aim of this study was to systematically review the implant survival rate and the complications associated with IAN reposition techniques with simultaneous implant placement in atrophic posterior mandibles. This systematic review was conducted following PRISMA guidelines (Preferred Reporting Items for Systematic review and Meta-Analysis). The review was designed to answer the following PICO question: Is IAN repositioning (I) a safe and efficient technique (O) to treat patient looking for fixed dental rehabilitation of an atrophic posterior mandible (P). Thirty-three articles were reviewed, including a total of 899 patients, and approximately 950 IAN repositioning procedures. Dental implant survival rate ranged between 86.95% and 100% with a mean dental survival rate of 90.16%. Among the 269 patients who underwent IANT, there were 93% immediate neurosensory disturbance, and 15% persistent neurosensory disturbance. Among the 350 patients who underwent IANL, there were 93% immediate neurosensory disturbance, and 6% persistent neurosensory disturbance. IANT and IANL are reliable techniques allowing safe dental implant placement in atrophic posterior mandible with high patient satisfaction. IANL seems to cause less persistent neurosensory disturbances compared to IANT. The level of evidence is poor due to the high number of bias present in the included studies. IAN neurosensory disturbance assessment should be better homogenized in order to increase comparability.

The placement of implants in the anterior maxillary and mandibular region requires esthetic proficiency and surgical finesse. It is important to consider the esthetic outcome while avoiding any type of nerve injury for the patient. In this literature review, anatomical structures of the anterior jaw were reviewed from a gross anatomical and radiographic interpretation. A discussion on the frequency of neurosensory complications for patients as a result of nerve damage in this region was evaluated. The purpose of this literature review was to educate the dental surgeon to consider the anterior jaw\'s neurological structures when performing procedures like implant surgery. The mandibular incisive canal (MIC) presents as an extension of the inferior alveolar canal that runs between the mental foramina. The MIC is a structure that is easily depicted in cone-beam computed tomography (CBCT) imaging and is present in most subjects in gross anatomical studies. The anterior loop of the mental nerve is another structure that is discussed in this paper. Although its structure is accurately depicted in CBCT images, its anatomical variations in patients can make implant treatment planning difficult. The maxilla contains 2 neurovascular structures that were discussed. First, the nasopalatine canal and its relation and impact on implant placement is evaluated. Case reports are reviewed that outline a prophylactic enucleation and bone grafting of the canal prior to implant placement. Second, the canalis sinuosus, which houses the anterior superior alveolar nerve, is of concern during implant placement in the lateral incisor region. Case reports involving nerve damage with follow-up are discussed.

Numb chin syndrome (NCS) is a rare sensory neuropathy resulting from inferior alveolar or mental nerve injury. It manifests as hypoesthesia, paraesthesia, or, rarely, as pain in the chin and lower lip. Several case reports suggest that sickle cell disease (SCD) could be a cause of NCS. However, information about NCS is scarce in this population. Our objectives were to synthesize all the available literature relevant to NCS in SCD and to propose recommendations for diagnosis and management based on the best available evidence. A systematic review was performed on several databases to identify all relevant publications on NCS in adults and children with SCD. We identified 73 publications; fourteen reports met the inclusion/exclusion criteria. These described 33 unique patients. Most episodes of NCS occurred in the context of typical veno-occlusive crises that involved the mandibular area. Radiological signs of bone infarction were found on some imaging, but not all. Neuropathy management was mostly directed toward the underlying cause. Overall, these observations suggest that vaso-occlusion and bone infarction could be important pathophysiological mechanisms of NCS. However, depending on the individual context, we recommend a careful evaluation to rule out differential causes, including infections, local tumors, metastatic disease, and stroke.

The aim of this study was to determine if the risk of neurological injury to the inferior alveolar nerve (IAN) and the lingual nerve (LN) following the extraction of lower third molars is affected by the anesthetic modality (local anesthesia (LA) vs. general anesthesia (GA)). A systematic search was performed through the PubMed, Scopus, Cochrane Library, and Web of Science databases; furthermore, a manual search was performed by analyzing the references of full-text articles. From a total of 309 studies (collected after the removal of duplicates), 6 studies were selected. Of these, 4 reported a correlation between GA and nerve damage, while the other 2 did not show an obvious association. The level of bias in the studies was also calculated. Only 2 studies showed a medium risk of bias, while 4 studies showed a high risk of bias; no study showed a low risk of bias. Four of the 6 studies highlighted a higher incidence of IAN and LN injury following the extractions performed under GA. Although no scientific evidence is yet available, due to the scarcity and the limited quality of the studies in the literature, considering the risk–benefit ratio, LA should be the first choice in lower third molar surgery.

In recent years, magnetic resonance imaging (MRI) has made great strides through various technical improvements and new sequences, which have made it one of the most promising and leading imaging techniques in the head and neck region. As modern imaging techniques in dentistry aim to reduce radiation exposure, this systematic review evaluated the possibilities, advantages, and disadvantages of advanced imaging diagnostics using dental MRI and its evidence for clinical indications and limitations relevant to mandibular third molar (MTM) surgery. Two reviewers performed multiple database searches (PubMed MEDLINE, EMBASE, Biosis, and Cochrane databases) following the PICOS search strategy using medical subject headings (MeSH) terms, keywords, and their combinations. Ten studies were included in this systematic review. By providing high spatial resolution and excellent soft tissue contrast, black bone MRI sequences such as 3D Double Echo Steady State (DESS) and 3D Short Tau Inversion Recovery (STIR) imaging protocols have the potential to become a valuable alternative to cone-beam computed tomography (CBCT) in future dental clinical routines. Overall, radiation-free MRI represents another step toward personalized dentistry and improved decision-making that avoids ineffectiveness and minimizes risks in oral surgery by taking into account additional patient-side factors such as comorbidity, anatomical norm variations, and imaging biomarkers.

Injury to the peripheral branches of the trigeminal nerve, particularly the lingual nerve (LN) and the inferior alveolar nerve (IAN), is a rare but serious complication that can occur during oral and maxillofacial surgery. Mandibular third molar surgery, one of the most common surgical procedures in dentistry, is most often associated with such a nerve injury. Proper preoperative radiologic assessment is hence key to avoiding neurosensory dysfunction. In addition to the well-established conventional X-ray-based imaging modalities, such as panoramic radiography and cone-beam computed tomography, radiation-free magnetic resonance imaging (MRI) with the recently introduced black-bone MRI sequences offers the possibility to simultaneously visualize osseous structures and neural tissue in the oral cavity with high spatial resolution and excellent soft-tissue contrast. Fortunately, most LN and IAN injuries recover spontaneously within six months. However, permanent damage may cause significant loss of quality of life for affected patients. Therefore, therapy should be initiated early in indicated cases, despite the inconsistency in the literature regarding the therapeutic time window. In this report, we present the visualization of two cases of nerve pathology using 3D double-echo steady-state MRI and evaluate evidence-based decision-making for iatrogenic nerve injury regarding a wait-and-see strategy, conservative drug treatment, or surgical re-intervention.

The aim of this retrospective study was to describe the etiology and characteristics of trigeminal nerve injuries referred to a specialized center in Buenos Aires, Argentina. A retrospective analysis was performed of patients referred from February 2016 to January 2020. Age, sex, intervention performed, nerve affected, time elapsed from injury, diagnosis, location, and whether patient had signed informed consent were recorded. A descriptive analysis of the data was made, and 95% confidence intervals were calculated for prevalence. The study sample consisted of 30 subjects (31 nerve injuries), 19 female and 11 male, average age (±SD) 40 ± 17 years. The inferior alveolar nerve was the most frequently injured nerve (74%,) while the lingual nerve accounted for 26%. The most common etiologies were inferior molar extractions (47%), dental implants (20%), and local anesthesia (13%). Other etiologies were autologous mandibular bone grafts for dental implants, removal of cysts associated with the inferior third molar, and endodontic treatment. Dental Institutions at which treatment was provided were found to be significantly associated with patients being warned and asked to sign informed consent (p<0.05), while dentists working at private offices requested fewer consents. The most frequent symptom was paresthesia, and 5 patients suffered spontaneous or evoked pain. Only 2 patients intended to file legal claims. Dentists should be aware of the debilitating effects resulting from trigeminal injuries, the complexity of their resolution and the importance of carefully planning dental procedures to prevent them.
El objetivo de este estudio fue describir la etiología y características de las lesiones del nervio trigémino remitidas a un servicio de referencia especializado en Buenos Aires, Argentina. Se realizó un análisis retrospectivo de los pacientes remitidos desde febrero de 2016 a enero de 2020. Se registraron edad, género, intervención recibida, nervio afectado, tiempo transcurrido desde la lesión, diagnóstico, ubicación y firma del consentimiento informado previo a la intervención Se realizó un análisis descriptivo de los datos y se calcularon intervalos de confianza del 95%. La muestra del estudio consistió en 30 sujetos (31 lesiones nerviosas), 19 mujeres y 11 hombres, con una edad promedio (± DE) de 40 ± 17 años. Aproximadamente 3 de cada 4 lesiones correspondieron al nervio alveolar inferior, representando el resto al nervio lingual. Las etiologías más frecuentes fueron la extracción dentaria (47%), los implantes dentales (20%) y la aplicación anestesia local (13%). Otras etiologías fueron la regeneración ósea para la colocación de implantes mandibulares, la extirpación de quistes asociados al tercer molar inferior y el tratamiento endodóntico. Se encontró que el tipo de establecimiento donde se realizó el procedimiento odontológico que generó la lesión, se asoció significativamente con los pacientes a los que se les advirtió y se les pidió que firmen el consentimiento informado (p<0.05); los odontólogos que trabajan en consultorios privados obtienen una menor proporción de consentimientos que los de las instituciones. El síntoma más frecuente fue la parestesia y 5 pacientes sufrieron dolor espontáneo o evocado. Solo 2 pacientes tenían intención de iniciar acciones legales. Teniendo en cuenta que son lesiones potencialmente permanentes, y de resolución compleja, la comunidad odontológica debe realizar especiales esfuerzos para disminuir esta complicación.

This systematic review aims to identify the available semi-automatic and fully automatic algorithms for inferior alveolar canal localization as well as to present their diagnostic accuracy. Articles related to inferior alveolar nerve/canal localization using methods based on artificial intelligence (semi-automated and fully automated) were collected electronically from five different databases (PubMed, Medline, Web of Science, Cochrane, and Scopus). Two independent reviewers screened the titles and abstracts of the collected data, stored in EndnoteX7, against the inclusion criteria. Afterward, the included articles have been critically appraised to assess the quality of the studies using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool. Seven studies were included following the deduplication and screening against exclusion criteria of the 990 initially collected articles. In total, 1288 human cone-beam computed tomography (CBCT) scans were investigated for inferior alveolar canal localization using different algorithms and compared to the results obtained from manual tracing executed by experts in the field. The reported values for diagnostic accuracy of the used algorithms were extracted. A wide range of testing measures was implemented in the analyzed studies, while some of the expected indexes were still missing in the results. Future studies should consider the new artificial intelligence guidelines to ensure proper methodology, reporting, results, and validation.