THE TRIGEMINAL NERVE 



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before it enters the mandibular foramen. It descends in a groove on the deep 

 surface of the ramus of the mandible, and reaching the under surface of the 

 Mylohyoideus supplies this muscle and the anterior belly of the Digastricus. 



The dental branches supply the molar and premolar teeth. They correspond 

 in number to the roots of those teeth; each nerve entering the orifice at the point 

 of the root, and supplying the pulp of the tooth ; above the alveolar nerve they form 

 an inferior dental plexus. 



The incisive branch is continued onward within the bone, and supplies the canine 

 and incisor teeth. 



The mental nerve (n. mentalis) emerges at the mental foramen, and divides 

 beneath the Triangularis muscle into three branches; one descends to the skin of 

 the chin, and two ascend to the skin and mucous membrane of the lower lip; these 

 branches communicate freely with the facial nerve. 



Two small ganglia, the otic and the submaxillary, are connected with the man- 

 iibular nerve. 





Fio. 783. The otic ganglion and its branches. 



Otic Ganglion (ganglion oticum) (Fig. 783). The otic ganglion is a small, oval- 

 shaped, flattened ganglion of a reddish-gray color, situated immediately below 

 the foramen ovale; it lies on the medial surface of the mandibular nerve, and 

 surrounds the origin of the nerve to the Pterygoideus internus. It is in relation, 

 laterally, with the trunk of the mandibular nerve at the point where the motor and 

 sensory roots join; medially, with the cartilaginous part of the auditory tube, 

 and the origin of the Tensor veli palatini; posteriorly, with the middle meningeal 

 artery. 



Branches of Communication. It is connected by two or three short filaments 

 with the nerve to the Pterygoideus internus, from which it may obtain a motor, 

 and possibly a sensory root. It communicates with the glossopharyngeal and facial 

 nerves, through the lesser superficial petrosal nerve continued from the tympanic 

 plexus, and through this nerve it probably receives a root from the glosso- 

 pharyngeal and a motor root from the facial; its sympathetic root consists of a 

 filament from the plexus surrounding the middle meningeal artery. The fibers 

 from the glossopharyngeal which pass to the otic ganglion in the small superficial 

 petrosal are supposed to be sympathetic efferent (preganglionic) fibers from the 

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