The lingual nerve (LN) is a branch of the mandibular division of the fifth cranial nerve, the trigeminal nerve, arising in the infratemporal fossa. It provides sensory fibers to the mucous membranes of the floor of the mouth, the lingual gingiva, and the anterior two-thirds of the tongue. Although the LN should rarely be encountered during routine and basic oral surgical procedures in daily dental practice, its anatomical location occasionally poses the risk of iatrogenic injury. The purpose of this section is to consider this potential LN injury risk and to educate readers about the anatomy of this nerve and how to treat it.

The lingual nerve (LN) is a branch of the mandibular division of the fifth cranial nerve, the trigeminal. It primarily carries sensory fibers from the lingual gingiva, mucous membranes of the floor of the mouth, sublingual gland, and the anterior two-thirds of the tongue. Recent studies have explored and reclassified the five branches of the LN as branches to the isthmus of the fauces, lingual branches, sublingual nerves, posterior branch to the submandibular ganglion, and branches to the sublingual ganglion. The knowledge of the LN anatomy and its variants is clinically relevant to avoid its injury during oral procedures. The objective of this paper is to review the literature on the LN and to describe the anatomy, its course, and its functions.

BACKGROUND: Iatrogenic mandibular nerve damage resulting from oral surgeries and dental procedures is painful and a formidable challenge for patients and oral surgeons alike, mainly because the absence of objective and quantitative methods for diagnosing nerve damage renders treatment and compensation ambiguous while often leading to medico-legal disputes. The aim of this study was to examine discriminating factors of traumatic mandibular nerve within a specific magnetic resonance imaging (MRI) protocol and to suggest tangible diagnostic criteria for peripheral trigeminal nerve injury.
METHODS: Twenty-six patients with ipsilateral mandibular nerve trauma underwent T2 Flex water, 3D short tau inversion recovery (STIR), and diffusion-weighted imaging (DWI) acquired by periodically rotating overlapping parallel lines with enhanced reconstruction (PROPELLER) pulse sequences; 26 injured nerves were thus compared with contra-lateral healthy nerves at anatomically corresponding sites. T2 Flex apparent signal to noise ratio (FSNR), T2 Flex apparent nerve-muscle contrast to noise ratio (FNMCNR) 3D STIR apparent signal to noise ratio (SSNR), 3D STIR apparent nerve-muscle contrast to noise ratio (SNMCNR), apparent diffusion coefficient (ADC) and area of cross-sectional nerve (Area) were evaluated.
RESULTS: Mixed model analysis revealed FSNR and FNMCNR to be the dual discriminators for traumatized mandibular nerve (p < 0.05). Diagnostic performance of both parameters was also determined with area under the receiver operating characteristic curve (AUC for FSNR = 0.712; 95% confidence interval [CI]: 0.5660, 0.8571 / AUC for FNMCNR = 0.7056; 95% confidence interval [CI]: 1.011, 1.112).
CONCLUSIONS: An increase in FSNR and FNMCNR within our MRI sequence seems to be accurate indicators of the presence of traumatic nerve. This prospective study may serve as a foundation for sophisticated model diagnosing trigeminal nerve trauma within large patient cohorts.

In primary therapy, a universally recognized surgical indication applies to all tumors of the salivary glands. According to the classic rule, radical resection of a head and neck tumor requires clean margins of at least 5 mm, although recent studies have shown that for certain locations, 1 mm may be sufficient. In the surgical resection of a tumor of the salivary glands, especially of the parotid gland, can these rules be respected? Owing to the complex branching and connections of the facial nerve within the parotid gland, even a medium-sized malignant tumor may be in contact with a branch of the nerve, thus raising the question of its preservation. The facial nerve is so important from a functional and aesthetic point of view that it is commonly believed that it should be preserved unless it is incorporated into the tumor. This is a compromise between an oncological resection, that is, the complete excision of the tumor with no residual cancer cells left behind, and quality of life. Almost all authors try to overcome this lack of radicality by indicating postoperative (chemo)radiotherapy. In this article, the pros and cons of nerve preservation will be analyzed by examining the published studies on this topic.

OBJECTIVE: This study aimed to evaluate the position of the mandibular lingula (ML) in adult patients (aged between 18 and 35 years old) with different skeletal and growth patterns using cone-beam computed tomography (CBCT).
METHODS: Cross-sectional.
METHODS: Dentistry department of University.
METHODS: Subjects comprised CBCT images of 150 adult patients, including 300 rami.
METHODS: In total, 150 CBCT aged between 18 and 35 were selected and divided into three main groups of 50 samples based on their skeletal relationships (classes I, II and III). Patients were subdivided based on their growth pattern (vertical vs. horizontal), resulting in 25 samples per subgroup. Distances between the mandibular lingula and occlusal plane (ML-OP), sigmoid notch (ML-SN), external oblique ridge (ML-EOR), internal oblique ridge (ML-IOR), posterior border of the ramus (ML-PBR), inferior border of the ramus (ML-IBR), and horizontal and vertical distances to the mandibular foramen (ML-hMF and ML-vMF). One-way ANOVA variance analysis was employed to compare different angle classifications, and Bonferroni analysis was used for multiple comparisons. The Student\'s t-test was also used to compare growth patterns within each main group and genders within the subgroup.
RESULTS: The study revealed statistically significant differences in the position of the mandibular lingula between different angle classifications, growth patterns, and genders. Class II samples showed a more anterior position of the ML, whereas Class III samples displayed a more posterior position of the ML. Patients with horizontal growth patterns and Angle Class III had a more posteriorly positioned ML. Gender differences were observed, particularly in Class I and Class III classifications, suggesting that gender may influence the variability of ML position in these specific classifications.
CONCLUSIONS: The position of the mandibular lingula showed high variability among individuals with different angle classifications, growth patterns and genders.

This case study describes anatomical variations in the branching pattern of the posterior division of the trigeminal nerve and its clinical implications for dental and craniofacial surgery. The study presents two uncommon variations observed in an elderly male cadaver. A communicating branch connecting one of three roots of the auriculotemporal nerve and inferior alveolar nerve just before entering the mandibular foramen on the right side, and three communicating branches between the IAN and lingual nerve on the left side. The presence of such variations may complicate anesthesia associated with oral surgery procedures.

BACKGROUND: Neurosensory deficits are one of the major complications after impacted lower third molar extraction leading to an impaired patient\'s quality of life. This study aimed to evaluate the incidence of neurosensory deficits after lower third molar extraction and compare it radiologically to the corresponding position of the inferior alveolar nerve.
METHODS: In a retrospective study, all patients who underwent impacted lower third molar extraction between January and December 2019 were compiled. Therefore, clinical data as well as preoperative radiological imaging were assessed.
RESULTS: In total, 418 patients who underwent lower third molar extractions (n = 555) were included in this study. Of these, 33 (5.9%) had short-term (i.e., within the initial 7 postoperative days) and 12 (1.3%) long-term (i.e., persisting after 12 months) neurosensory deficits documented. The inferior alveolar nerve position in relation to the tooth roots showed apical position in 27%, buccal position in 30.8%, lingual position in 35.4%, and interradicular position in 6.9%.
CONCLUSIONS: A statistically significant increased incidence of neurosensory deficits occurs when the inferior alveolar nerve is directly positioned lingually to the tooth roots (p = 0.01).

暂无摘要。

OBJECTIVE: The aim of this study is to evaluate the relationship between the inclination/impaction depth and root proximity to the inferior alveolar canal/lingual plate on a millimeter scale using CBCT scans.
METHODS: 340 CBCT scans of the mandibular third molar (M3) of 219 patients were evaluated for this cross-sectional study. After adjustment of the 3D orientation of the individual\'s jaws, the study variables including the angulation between M3 and second molar (M2)/occlusal plane (OP), and the distance of mesial (M)/distal (D) roots of M3 from the inferior alveolar canal (IAC) and lingual plate (LP) were measured. Winter\'s classification was used for the specification of teeth angulation. The vertical position of each M3 was then evaluated using the 3D view window (based on Pell & Gregory classification). The Spearman correlation coefficient was used for reporting the correlation between quantitative variables. The One-way ANOVA test and the Welch analysis were used for inter-group comparisons. Finally, a multivariant analysis of variances was performed.
RESULTS: Most third molars had a mesioangular inclination (52.1%), and vertical inclination (25.9%) was in second place. There was no significant correlation between angulation and age or the D/LP. A strong positive correlation between M3:M2 and M3:OP was observed (0.983). Furthermore, there was a weak negative correlation between M/IAC or M/LP and angulation (- 0.16 and - 0.13, respectively). Concerning Winter\'s classification, the relationship between D/IAC and angulation was statistically significant (P = 0.003). Furthermore, teeth in position A had lesser inclination compared to those with B or C positions. Multivariate analysis revealed that there was no statistically significant relationship between particular combinations of inclination-impaction depth and proximity of the M3 roots to the IAC or LP (P = 0.211).
CONCLUSIONS: The findings of the current study revealed that there is a strong correlation between M3:M2 and M3:OP. The D/IAC was the only variable that had a significant relationship with the angulation of these teeth. Moreover, the roots of horizontally inclined teeth with position A were the closest to the LP and the farthermost to the IAC.

Guillain-Barré syndrome (GBS) is a rare rapid onset autoimmune peripheral polyneuropathy, most commonly characterized by inflammatory demyelination of peripheral nerves. Patients with GBS are considered higher risk for anesthetic-induced neurotoxicity caused by demyelination. In the present report, a case is described of a 56-year-old man with GBS who experienced mental and lingual nerve paresthesia following infiltration anesthesia for dental implant placement in the posterior mandible. The pareshesia lasted 5 months postoperatively and subsided spontaneously without any intervention. The patient was successfully restored with fixed partial dental prosthesis without any other complication. This is considered the first report of such complication in patient with GBS after local anesthesia in the oral and maxillofacial region. Possible pathogenic mechanism of the complication and clinical implications are discussed.