How Is the Arterial Supply to the Maxillary and Mandibular Teeth?
The neurovascular supply to the teeth is quite rich and is due to the same sources that immediate the upper and lower jaws.
The arterial supply to the jawbones and the teeth comes from the maxillary artery, 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. The inferior alveolar artery branches from the maxillary artery medial to the ramus of the mandible. 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.
It divides into mental and incisive branches in the vicinity of the mental foramen. The mental branch, in turn, passes through the mental foramen to supply the tissues of the chin and to anastomose with the inferior labial and submental arteries. The incisive branch moves forward into the bone to supply the anterior teeth and bone and to anastomose those of the opposite side. The anastomosis of the mental and incisive branches furnishes a good collateral blood supply for the mandible and teeth.
Other branches that enter the interdental septa usually supply the bone and adjacent periodontal membranes. These accessory branches terminate in the gingiva. Numerous small anastomoses connect the vessels with those supplying the neighboring alveolar mucosa.
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The posterior superior alveolar artery branches from the maxillary artery superior to the maxillary tuberosity. It enters the alveolar canals along with the posterior superior alveolar nerves and supplies the maxillary teeth, alveolar bone, and membrane of the sinus.
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A middle superior alveolar branch is usually given off by the infraorbital continuation of the maxillary artery somewhere along the infraorbital groove or canal.
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Anterior superior alveolar branches arise from the infraorbital artery just before this vessel leaves its foramen. They course down the anterior aspect of the maxilla in bony canals to supply the maxillary anterior teeth and their supporting tissues and join the middle and posterior superior alveolar branches in completing an anastomotic plexus.
The palatal blood supply comes from two sources but chiefly from the descending palatine artery. Its greater palatine branch enters the palate through the greater palatine foramen. It is distributed to the bone, glands, and mucosa of the hard palate and to the bone and mucosa of the alveolar process.
How Is the Nerve Supply to the Maxilla?
The sensory nerve supply to the jaws and teeth is derived from the maxillary and mandibular branches of the fifth cranial, or trigeminal nerve, whose ganglion, the trigeminal, is located at the apex of the petrous portion of the temporal bone. The innervation of the orofacial region includes, in addition to the trigeminal nerve (including V2 and V3), other cranial nerves; the maxillary nerve courses forward through the wall of the cavernous sinus and leaves the skull through the foramen rotundum. It crosses the pterygopalatine fossa, where it gives branches to the pterygopalatine ganglion, a parasympathetic ganglion. This ganglion gives off several branches containing visceral motor and sensory fibers to the mucous membrane of the mouth, nose, and pharynx.
The maxillary nerve also has a posterior superior alveolar branch from its pterygopalatine portion. This nerve enters the alveolar canals on the infratemporal surface of the maxilla and, forming a plexus, it is distributed to the molar teeth and the supporting tissues. The maxillary nerve enters the orbit and, as the infraorbital nerve, runs forward on its floor, first in the infraorbital groove and then in the infraorbital canal. Finally, it terminates at the infraorbital foramen in branches distributed to the upper face.
At a variable distance, after it enters the orbit, a middle superior alveolar branch arises from the infraorbital nerve and runs through the lateral wall of the maxillary sinus. It is distributed to the premolar teeth and surrounding tissues and joins the alveolar plexus.
How Is the Nerve Supply to the Mandible?
The mandibular nerve leaves the skull through the foramen ovale. The chief branch of the lower jaw is the inferior alveolar nerve. It 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. 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.
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. They extend from the canine to the third molar.
The lingual nerve has mucosal branches to a variable area of lingual mucosa and gingiva. The mylohyoid nerve may sometimes continue its course forward on the lower surface of the mylohyoid muscle and enter the mandible through a small foramina on either side of the midline. In some individuals, it is thought to contribute to the innervation of central incisors and periodontal ligaments.
What Happens When the Arterial and Nerve Supply to the Teeth Is Cut Off?
When a tooth usually undergoes traumatic stress such as a fall, severe decay, injury, fracture, subluxation, or even avulsion, then the neurovasculature supply is likely to be cut off as a result of which the tooth may turn discolored, undergo internal root resorption or even turn completely non-vital. A vital tooth can still warranty endodontic treatment or root canal procedure. However, when the prognosis of the tooth to be saved is poor, it will eventually be indicated for extraction by the dental surgeon.
Conclusion:
The nerve supply and blood supply to the teeth both in the maxilla and mandible, that is, the upper and lower jaws, are the source of vitality and life to the whole dentition. Therefore, any damage or infection to this rich vasculature necessitates the need for endodontic or surgical treatment to restore dental functionality and form.