The Correlated Anatomical Study On Amputation And Avulsion Of Branch Of Trigeminal Nerve

The primary trigeminal neuralgia(TN) is one of the common neural disease in oral and maxillofacial region,which its therapy is various for its etiological factors and mechanisms unknown at present.The neurotomy of the peripheral branch and neurectomy of the terminal nerve of trigeminal nerve,created in our department recently,is one of simple and effective approaches.For the maxillary nerve,the operation is practiced in the narrow pterygopalatine fossa through the maxillary sinus,and it is done among the soft tissues in the pterygomandibular space for the mandibular nerve .They are both partly difficult.Furthermore,some patients have the leaved pain on the palate and the upper lip.Objective:Through anatomical study of extracranial section of trigeminal nerve,to make sure the courser, branch, and the relationship of artery and nerve of trigeminal nerve,to known the distribution of sensory fibers of trigeminal nerve on face,to provide safe and operative approach for amputation and avulsion of branch of trigeminal nerve ,and to reduce the relapse rate.Methods:Fifteen(male 10,female 5) skulls, fixed by formaldehyde solution and their arteries perfused by red lacteprene, were used to dissect under the operating mgcroscop(×10) by the following order: 1, To dissect the terminal branch of trigeminal nerve and to observe the anatomical figure of it.2, To dissect the pterygopalatine fossa and observe the structures in it and the interrelationship..3, To dissect the infratemporal fossa and the pterygomandibular space .Results:1, The distribution of sensory fibers of trigeminal nerve are abundant at the maxillofacial region,the number of neural foramen is not single,and osseous tunnels are bing.2, There are common and extensive connections between the trigeminal nerve and the facial nerve.3, There are direct and indirect communicationsamong branches of the trigeminal nerve.4> The mandibular nerve does not end in the mental nerve,but extends to the midline in the mandibular canal.5 > In the pterygopalatine fossa,courser directions of the infraorbital nerve and the descending palatine nerve are vertical each other.6> There is some position relation between nerves and arteries. In the lateral part of the pterygopalatine fossa, artery is under the trunk of the maxillary nerve; In the superior part, artery is before the pterygopalatine ganglion; The artery always lies to the lateral of the descending palatine nerve in the medial part of the fossa. 7> The inferior alveolar nerve enters the mandibular canal behind the mandibular lingual.The distance from the mandibular lingual to the anterior border of the ramus of mandible and the inferior border of the body of mandible are 14.8+1.6mm (13.0~17.7mm) and32.9±2.7mm (29.0~37.4mm) . The distance from the lingual nerve to the internal oblique line is 5.2+1.2mm (3.3~6.6mm) .The point ,which the buccal nerve intersects the anterior border of the ramus of mandible,is named A.The distance from the A to end of the anterior border of the ramus of mandible -. the superior border and the inferior border of the body of mandible are 6.6+2.0mm (3.0~10.3mmX 18.5+4.7mm (10.0~27.6mm) and 38.5 + 2.4mm (34.8~43.8mm)oConclusions: 1> The direct and indirect communication between maxillary nerve and mandibular nerve > the part in the incisive canal of mandibular nerve *. the osseous canals and multiple neural foramens maybe were the cause for recurrent postoperative pain and transferred pain.2> The common and extensive connections between the trigeminal nerve and the facial nerve maybe was the cause of facial spas following TN.This connection between sensory nerve and motor nerve could provide new idea for the plasty of facial nerve.3> In the amputation of maxillary nerve, the infraobital nerve and the descending palatine nerve should be treated separately.The past operation should have only broken the former one.4> The relation of nerves and blood vesses or nerve and nerve can do some well to localization at surgery,and exposing structures ,Uke walls of the maxillary sinus > the mandibular linguah the internal oblique line and the anterior border of the ramus of mandible,are the good reference.These provide safe and convenient approach for the operation.