SciCombinator

Discover the most talked about and latest scientific content & concepts.

Concept: Lingual nerve

0

Presence of accessory submandibular salivary gland (ASSG) is an extremely rare variation. Knowledge of its relations could be very useful to oral and maxillofacial surgeons, head and neck surgeons, and radiologists. During dissection classes, an ASSG was noted between the mylohyoid and hyoglossus muscles. The main submandibular salivary gland had superficial and deep parts. The deep part was narrow and measured about 5 cm. The lingual nerve passed between the superficial and deep parts. The accessory submandibular gland was situated below and parallel to the deep part of SSG. It also measured 5 cm. The ASSG had its own duct, which joined the duct of main gland. The ASSG and the deep part of the SSG were united at the lateral border of geniohyoid muscle to give a characteristic “horseshoe” appearance. The ASSG overlapped both lingual and hypoglossal nerves.

Concepts: Muscle, Nerve, Oral and maxillofacial surgery, Salivary gland, Submandibular gland, Sublingual gland, Lingual nerve, Hyoid bone

0

A female patient, now aged 17 years, was diagnosed with rhabdomyosarcoma (RMS) in the right pterygopalatine fossa when she was 3 years old. The RMS was successfully treated by excision, but the subsequent radiation and polychemotherapy resulted in the complete anesthesia of the distribution area of the right trigeminal nerve and loss of vision in the right eye. The patient also experienced pain in the mandibular joints and masticatory muscles. Panoramic radiographs displayed a multiple agenesia of the permanent teeth and underdeveloped apices. Treatment involved the fabrication of a complete maxillary denture. A removable device was fabricated to evaluate her response to an occlusal vertical dimension increase of 6 mm and provide a stable intercuspal position. After wearing the prosthesis for 6 months, the patient reported that she was completely free of symptoms.

Concepts: Cranial nerves, Prosthesis, Mandibular nerve, Dentures, Trigeminal nerve, Maxillary nerve, Lingual nerve

0

With the growing demand for dental work, trigeminal nerve injuries are increasingly common. This retrospective cohort study examined 53 cases of iatrogenic trigeminal nerve injury seen at the Department of Oral and Maxillofacial Surgery, University Hospitals of Leuven between 2013 and 2014 (0.6% among 8845 new patient visits). Patient records were screened for post-traumatic trigeminal nerve neuropathy caused by nerve injury incurred during implant surgery, endodontic treatment, local anaesthesia, tooth extraction, or specifically third molar removal. The patients ranged in age from 15 to 80years (mean age 42.1years) and 68% were female. The referral delay ranged from 1day to 6.5years (average 10months). The inferior alveolar nerve (IAN) was most frequently injured (28 cases), followed by the lingual nerve (LN) (21 cases). Most nerve injuries were caused during third molar removal (24 cases), followed by implant placement (nine cases) and local anaesthesia injuries (nine cases). Pain symptoms were experienced by 54% of patients suffering IAN injury, compared to 10% of patients with LN injury. Persistent neurosensory disturbances were identified in 60% of patients. While prevention remains the key issue, timely referral seems to be a critical factor for the successful treatment of post-traumatic neuropathy.

Concepts: Cohort study, Surgery, Dental implant, Dentistry, Oral and maxillofacial surgery, Mandibular nerve, Trigeminal nerve, Lingual nerve

0

Fungiform papillae on human tongue are the proxy structures designated to oral stimuli detection and transduction. However, the role of their density (fungiform papillae/cm2) in explaining oral sensitivity is still controversial. While early studies generally found that the responsiveness to oral stimuli increased as the number of papillae increased, recent large-scale studies failed to confirm this finding.The present paper reviews relevant studies dealing with the relationship between fungiform papillae density and responsiveness to oral sensations including: fundamental tastes, 6-n-propyl-2-thiouracil (PROP) and sensations from trigeminal stimulation.Manual methods and automated methods for papillae detection and quantification are reviewed and their advantages and limitations highlighted. The main factors affecting fungiform papillae density and functionality (age, gender, pathologic impairments) are also considered. Possible bias related to methodological issues in counting technique (equipment used, area and location of the tongue to count, procedures to validate the count), population sample (demographics) and sensory response collection (threshold or supra-threshold stimuli, intensity scaling) are illustrated.The lack of information related to the variability in taste pores density and the possible impairments due to nerve damages, may obscure the relationship between FPD and oral responsiveness.

Concepts: Scientific method, Taste, Mandibular nerve, Tongue, Gustatory system, Taste bud, Lingual nerve, Fungiform papilla

0

The tongue is a dense muscular organ, in which the muscles are arranged in a confusing pattern. The intrinsic muscles were gross anatomically investigated in 25 cadavers to clarify their configuration. The superior longitudinal muscle (SLm) ran beneath the dorsal mucosa and was divided into bundles by the other muscles passing through it to the dorsum. The external bundle of the styloglossus, with the palatoglossus, coursed externally to the hyoglossus. Their fibers spread beneath the SLm or attached to the apex and the inferior longitudinal muscle (ILm) ascended from the root and joined them. The genioglossus and the anterior part of the hyoglossus extended internally and externally to the ILm, respectively, to the dorsum, and the vertical muscle was sandwiched between them. The transverse muscle passed laterally from the lingual septum. The fibers of the posterior part of the hyoglossus converged to the root and spread beneath the SLm. The intersections between these vertical and transverse fibers divided one another into bundles or lamellae. The middle bundle of the styloglossus, passing between the two parts of the hyoglossus, was divided into slips by the intersection with the genioglossus. The internal bundle of the styloglossus, with the glossopharyngeus, descended internally to the posterior part to the root. The findings indicate that the intrinsic and extrinsic muscles of the tongue are not independent groups, and their fibers form a three-dimensional latticework. Each muscle contains numerous bundles or lamellae as functional units that can act separately or cooperate across the muscles.

Concepts: Heart, Muscle, Muscular system, Anatomical terms of location, Tongue, Lingual nerve, Hypoglossal nerve, Lingual artery

0

Repeated administration of chlorpyrifos (CPF), an organophosphate pesticide, can increase the risk of oral cytotoxicity. The current study was designed to assess the mechanism by which CPF mediates its cytotoxic effect on lingual mucosa of rats. Twenty-four male Wistar rats were used in the present study and divided into three groups: group I: healthy rats (negative control), group II: rats treated with CPF 1/40 LD50 (3.375 mg/kg, orally/daily) for 28 days, group III: rats treated with CPF 1/10 LD50 (13.5 mg/kg, orally/daily) for 28 days. At the end of the experiment, all rats were sacrificed by cervical dislocation under ketamine anesthesia. Tongue samples were dissected out at their base for detection of heme oxygenase-1 (HO-1) and nuclear erythroid 2-related factor 2 (Nrf-2) by western blotting and histopathological and electron microscopic studies. Immunostaining was used to determine cleaved caspase 3 and the nuclear factor kappa B (NF-κB) localization. Structural and ultrastructural examination of treated lingual mucosa with CPF demonstrated degenerative changes that involved both the dorsal and ventral surfaces of the tongue as well as the lingual glands. CPF-treated rats demonstrated a significant increase in the levels of pro-inflammatory cytokines such as interleukin-1β (IL-1β) and tumor necrosis factor (TNF-α) in addition to a significant dose-dependent activation of NF-κB and cleaved caspase 3. Furthermore, CPF activated HO-1 and Nrf-2 pathway in a dose-dependent manner. In conclusion, this data suggests that the CPF-induced cytotoxicity may be explained by NF-κB activated inflammatory cascade. In addition, CPF triggers an adaptive activation of Nrf-2/HO-1 pathway.

Concepts: Inflammation, Apoptosis, Tumor necrosis factor-alpha, Organophosphate, VX, Tongue, Lingual nerve, NF-κB

0

Lingual hematoma (LH) is a relatively uncommon entity seen after both medical and traumatic etiologies. Regardless of the cause, the feared complication is acute airway obstruction.

Concepts: Medicine, Temporomandibular joint, Joint dislocation, Lingual nerve

0

The aim of the study was to evaluate the relations between submandibular duct, lingual nerve and hypoglossal nerve for making a reassessment of this area in fresh frozen specimens. Also, the distance between the angle of the mandible and the vertical line drawn from the point where submandibular duct crossed lingual nerve to the base of the mandible was measured to determine a new landmark for neck surgeons.

Concepts: Cranial nerves, Internal jugular vein, Tongue, Lingual nerve, Hypoglossal nerve, The Point, Genioglossus, Hyoglossus

0

The anterior mandible is generally regarded as a safe anatomical region for implant placement. However, anatomical variations may lead to severe intraoperative complications with potential fatal outcome. The objective of this study was to evaluate the anterior mandibular lingual defect (AMLD) in patients undergoing implant surgery.

Concepts: Mandible, Retrospective, Physician, Dental implant, Dentistry, Oral and maxillofacial surgery, Osseointegration, Lingual nerve

0

The tongue is covered by fungiform, filiform and circumvallate papillae. Fungiform papillae may be mainly pigmented in dark-skinned individuals.

Concepts: Tongue, Gustatory system, Taste bud, Lingual nerve, Papilla, Filiform papilla, Fungiform papilla, Circumvallate papillae