Blood and nerve supply of teeth

Oral Anatomy
DR.PRIYADHARSHINI

1. Blood and nerve supply to teeth Dr.N.Priyadharsini Department of oral and maxillofacial pathology Srm dental college, ramapuram

2. Blood supply of teeth The arterial supply to the jaw bones and the teeth comes from the maxillary artery, which is a branch of the external carotid artery The branches of the maxillary artery that feed the teeth directly are the inferior alveolar artery and the superior alveolar arteries

3. One of the terminal branches of the external carotid artery, the maxillary artery is the artery of the jaws and teeth. It originates from the external carotid artery behind the neck of the mandible.

4. The course of the maxillary artery is divided into three parts by its relation to the lateral pterygoid muscle. From the neck of the mandible, it runs across the lower border of lower head of lateral pterygoid muscle and then crosses between the two heads of lateral pterygoid to go through the pterygomaxillary fissure and reach the pterygopalatine fossa. Various branches are given off during the entire course, supplying numerous structures

5. BRANCHES: Mandibular Pterygoid Pterygopalatine

6. MAXILLARY ARTERY-Pterygopalatine branch Posterior superior alveolar branch: This branch is given off before the maxillary artery enters the pterygomaxillary fi ssure . The arteries perforate the posterior surface of the maxilla to supply the teeth of upper jaw—the premolars and molars—and the maxillary sinus.

7. MAXILLARY ARTERY-Pterygopalatine branch Infraorbital branch: This branch passes through the inferior orbital fissure to reach the floor of the orbit. It runs over the infraorbital groove and then into the infraorbital canal to finally open onto the face through the infraorbital foramen, which is present below the lower margin of orbit. Branches of the infraorbital artery are as follows: ( i ) Branches before exiting the orbit: Anterior superior alveolar branches that supply the canine and incisors (ii) Branches after exiting the orbit: Branches to the lacrimal sac, nose and upper lip

8. Inferior alveolar artery The inferior alveolar artery branches from the maxillary artery medial to the ramus of the mandible. Protected by the sphenomandibular ligament, it gives off the mylohyoid branch, which rests in the mylohyoid groove of the mandible and continues along on the medial side under the mylohyoid line. After giving off the mylohyoid branch, it immediately enters the mandibular foramen and continues downward and forward through the mandibular canal, giving off branches to the premolar and molar teeth.

9. In the vicinity of the mental foramen, it divides into a mental and an incisive branch. The mental branch passes through the mental foramen to supply the tissues of the chin The incisive branch continues forward in the bone to supply the anterior teeth and bone and to anastomose with those of the opposite side.

10. Nerve supply The sensory nerve supply to the jaws and teeth is derived from the maxillary and mandibular branches of the fifth cranial, or trigeminal nerve

11. Maxillary nerve It is the second division of the trigeminal nerve and is positioned between the ophthalmic and mandibular divisions. It is sensory in function, carrying sensations from the maxillary region. BRANCHES: Cranium Pterygopalatine fossa Infraorabital canal Face

12. The posterior superior alveolar branches - are given off from the main trunk before it reaches the infraorbital groove in the pterygopalatine fossa. They run vertically down towards the maxillary tuberosity. Several tiny branches arise to innervate the gums and adjacent mucous membrane of the cheek. Later, they penetrate the infratemporal surface of the maxilla to enter the posterior alveolar canals and supply the lining of maxillary sinus as well as provide pulpal innervation to molar teeth by passing through the foramina at the root apices of teeth.

13. The middle superior alveolar branch arises in the posterior part of the infraorbital canal. It takes a course along the lateral wall of the maxillary sinus to provide pulpal innervation to the two premolar teeth and the associated buccal mucoperiosteum.

14. The anterior superior alveolar branch originates from the main nerve just before its exit from the infraorbital foramen. It reaches the incisors and canines by running across a canal in the anterior wall of the maxillary sinus and provides pulpal innervation

15. Mandibular nerve

16. The mandibular nerve leaves the skull through the foramen ovale and almost immediately breaks up into its several branches. The chief branch to the lower jaw is the inferior alveolar nerve, which at first runs directly downward across the medial surface of the lateral pterygoid, at the lower border of which it is directed laterally and downward across the outer surface of the medial pterygoid muscle to reach the mandibular foramen

17. The inferior alveolar nerve continues forward through the mandibular canal beneath the roots of the molar teeth to the level of the mental foramen. During this part of its course, it gives off branches to the molar and premolar teeth and their supporting bone and soft tissues.

18. At the mental foramen, the nerve divides and a smaller incisive branch continues forward to supply the anterior teeth and bone, and a larger mental branch emerges through the foramen to supply the skin of the lower lip and chin.

19. The buccal nerve, although chiefly distributed to the mucosa of the cheek, has a branch that is usually distributed to a small area of the buccal gingiva in the first molar area, but in some cases, its distribution may extend from the canine to the third molar. The lingual nerve, as it enters the floor of the mouth, lies against the body of the mandible and has mucosal branches to a variable area of lingual mucosa and gingiva.

20. The mylohyoid nerve may sometimes continue its course forward on the lower surface of the mylohyoid muscle and enter the mandible through small foramina on either side of the midline. In some individuals, it is thought to contribute to the innervation of central incisors and periodontal ligament.