The lingual nerve (LN) is a branch of the mandibular division of the trigeminal nerve, and its injury is one of the major complications during oral surgery. This study aims to investigate the anatomy of the LN in the lower third molar area. Twenty sides from ten fresh-frozen adult cadaveric Caucasian heads were examined to measure the diameter of the LN. The mean diameter of the LN was 2.20±0.37 mm (range, 1.61–2.95 mm). There were no statistically significant differences in the measurements between sexes, sides, or tooth status (dentulous or edentulous). Understanding the anatomical features of the LN is essential for performing any surgical procedure in the oral region.
Adult ; Cadaver ; Head ; Humans ; Lingual Nerve ; Mandibular Nerve ; Molar, Third ; Surgery, Oral ; Tooth ; Trigeminal Nerve

The purpose of this study was to investigate the courses of the maxillary artery and variations of the arteries and nerves in the infratemporal fossa from 36 Korean adult cadavers. The results were as follows; 1. In the majority of the cases (81.9%), course of the maxillary artery runs lateral to the lateral pterygoid muscle. 2. The variations of the arteries and nerves in the infratemporal fossa could be classified into six types. In the most common (type 2, 61.1%), the maxillary artery runs lateral to the lateral pterygoid muscle, and the inferior alveolar lingual and buccal nerves lie medial to the maxillary artery. In the next (type 1, 20.8%), the maxillary artery runs lateral to the lateral pterygoid muscle and the inferior alveolar and lingual nerves lie medial to the maxillary artery, and buccal nerve lies lateral to the maxillary artery. The remaining types were type 3 (7.0%), type 4 (4.2%), type 5 (5.6%) and type 6 (1.4%) in order.
Adult ; Arteries* ; Cadaver ; Humans ; Lingual Nerve ; Mandibular Nerve ; Maxillary Artery ; Pterygoid Muscles

INTRODUCTIONThe lingual, inferior alveolar and auriculotemporal nerves, being branches of the posterior division of the mandibular nerve, mainly innervate the mandibular teeth and all the major salivary glands. Anomalous communications among these branches are widely reported due to their significance to various treatment procedures undertaken in the region. This study was performed as detailed exploration of the functional perspectives of such communicating branches would further enhance the scope of these procedures.

METHODSA total of 36 specimens were dissected to examine the infratemporal region. The branches from the posterior division of the mandibular nerve--namely the lingual, inferior alveolar and auriculotemporal nerves--were carefully dissected, and their branches were studied and analysed for abnormal course.

RESULTSCommunication between branches of the posterior division of the mandibular nerve was observed in four specimens. In two of the four specimens, communication between the mylohyoid and lingual nerves was observed. A rare and seldom reported type of communication between the auriculotemporal and inferior alveolar nerves is described in this study. This communicating nerve split into two to form a buttonhole for the passage of the mylohyoid nerve.

CONCLUSIONSuch communicating branches between nerves found in this study are developmental in origin and thought to maintain functional integrity through an alternative route.

Cadaver ; Female ; Humans ; Lingual Nerve ; anatomy & histology ; Male ; Mandibular Nerve ; anatomy & histology ; Neck Muscles ; innervation ; Tongue

Two major salivary glands, submandibular duct, lingual nerve, and vessels are situated beneath the mouth floor. Among these, passing through the pterygomandibular space, lingual nerve is innervated to the lingual gingiva and the mucosa of mouth floor, and is responsible for the general sensation of the anterior two thirds of the tongue. So, the injury of the lingual nerve during an anesthesia or surgery in the retromolar area may cause complications such as a numbness, a loss of taste of the tongue and the other dysfunctions. Therefore, to find out the morphology and the course of lingual nerve and to clarify the topographical relationships of lingual nerve at the infratemporal fossa and paralingual space area, 32 Korean hemi-sectioned heads were dissected macroscopically and microscopically with a viewpoint of clinical aspect in this study. This study demonstrated various anatomical characteristics with relation to the course and topography of the lingual nerve in Koreans. And clinical significances based on the anatomical variations through the topography of the courses and communications between the mandibular nerve branches were described in details.
Anesthesia ; Chorda Tympani Nerve ; Gingiva ; Head ; Hypesthesia ; Lingual Nerve* ; Mandibular Nerve ; Mouth Floor ; Mucous Membrane ; Salivary Glands ; Sensation ; Tongue

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.
Chronic Pain ; Depression ; Erythropoietin ; Humans ; Lingual Nerve ; Mandibular Nerve ; Molar, Third ; Neuroprotection ; Postoperative Complications ; Regeneration ; Stem Cells ; Translational Medical Research ; Trigeminal Nerve Injuries ; Trigeminal Nerve

The extraction of an impacted third molar tooth is associated with many complications during the procedure and postoperative care. These complications include bleeding, swelling, pain, infection, as well as root fracture, proximal tooth injury, alveolar bone fracture, lingual nerve and inferior alveolar nerve injury etc. With the exception of a fractured root dislocation in the submandibular space, no direct submandibular gland injury related to extraction surgery has been reported until now. A 40 year old man visited the department of oromaxillofacial surgery at Yeouido St. Mary's Hospital for an extraction of the right mandible third molar. A partial third molar impaction was diagnosed by a clinical and radiographic examination. A surgical tooth extraction was practiced including buccal cortical bone osteotomy. During socket curettage, an encapsulated cyst-like lesion and a verified 3x3 cm neoplasm in the apically lingual direction were found during process of dissection. A biopsy confirmed that the neoplasm involved the submandibular gland and nerve trunk. This unusual anatomical organ injury during the surgical tooth extraction procedure is reported as a new complication during impacted third molar extraction.
Biopsy ; Curettage ; Dislocations ; Fractures, Bone ; Hemorrhage ; Intraoperative Complications ; Lingual Nerve ; Mandible ; Mandibular Nerve ; Molar, Third ; Osteotomy ; Postoperative Care ; Submandibular Gland ; Tooth ; Tooth Extraction ; Tooth Injuries

OBJECTIVETo observe the morphologic changes of inferior alveolar nerve before and after osteocompression on dog's mandible.

METHODS8 dogs were selected and divided into 4 groups, 2 dogs per group. The osteocompressor was fixed on the right buccal side of the mandibule. Crew the compressor to compress the mandible 1.0 mm per 3 days for totally 15 days. On the 1st day, 15th day, 45th day and 90th day after osteocompression, the dogs of different groups were killed respectively. Get the inferior alveolar nerve and HE staining was carried on.

RESULTS(1) On the 1st, 15th and 45th day after osteocompression, the fiber of the inferior alveolar nerve was obviously injured. (2) On the 90th day after osteocompression, the injured nerve was almost recovered to normal.

CONCLUSIONThe osteocompression could cause temporary injury on the inferior alveolar nerve, but the injury was reversible and might recovere by times after osteocompression.

Animals ; Dogs ; Mandible ; Mandibular Nerve

OBJECTIVETo establish a stable mandibular fracture model with inferior alveolar nerve (IAN) mutilated for exploring the IAN influence to the expression of collagen I during mandibular fracture.

METHODSJapanese white rabbits were selected and IAN was liberated. The right was leaven as it is and the left was cut off, then 2 mm x 5 mm fracture model was made, and HE staining and chromotropic acid 2R-bright green staining and in situ hybridization of collagen I mRNA were made to detect mandibular fracture healing and collagen I mRNA expression.

RESULTSFracture healing was smooth in IAN conserved side, but delayed in the IAN mutilated side. Collagen I in situ hybridization showed that at one week and two weeks after surgery there were obvious differences between the two sides (P < 0.05), but no difference at three weeks after surgery and four weeks (P > 0.05).

CONCLUSIONThe IAN could regulate mandibular fracture healing, and influence collagen I mRNA earlier expression.

Animals ; Collagen ; Mandible ; Mandibular Fractures ; Mandibular Nerve ; Rabbits

Various treatment methods for huge cystic lesion of the jaw exist, such as, resection of the involved bone, enucleation and decompression. Among these methods, enucleation after decompression is a conservative technique that decreases the size of the cystic cavity and reduces the risk of intrabony defects, which could be induced by primary enucleation. In addition, it can save the adjacent anatomic structures. In these cases, the decompression combined with partial enucleation, which was performed before complete cyst enucleation was performed on huge cystic lesions of the mandible. During the process, a decrease in the size of the lesion and the growth of normal oral tissues was observed. The size of the lesion decreased until the time of complete enucleation, and surgery could be performed under local anesthesia. No damage to inferior alveolar nerve was observed. We report these cases with a review of the relevant literature.
Anesthesia, Local ; Decompression ; Jaw ; Mandible ; Mandibular Nerve

Fifteen dry dentate and complete mandible samples from the White Rasquera goat breed were studied for symmetry. Thirty-one landmarks were digitally located on the images of the lateral and medial aspects of each hemimandible. Distances between these landmarks allowed the evaluation of the whole hemimandible and also the neural mandible. In the studied samples, the mandible was rather symmetrical, especially in the medial neural part, and in general, there was no side dominance. Only the diastema differed significantly between the sides, and this was related to the rostral part (incisive arch). The incisive region was the least symmetrical region of the caprine mandible, indicating a modular structure more conservative for the neural part. If unsigned asymmetry is interpreted as a measure of developmental stability, then the studied breed presented a marked ability to develop in good fitness despite the harsh environment. The measurements presented here can also be used as a reference for researchers designing experimental studies, especially on mandibular catch-up growth, and as an aid for zooarchaeologists comparing results from dead animals with those from living goat populations.
Animals ; Diastema ; Goats ; Jaw ; Mandible* ; Mandibular Nerve