When it comes to your oral health, there's more to think about than just teeth and gums. It's also worth understanding the anatomy and makeup of your jaw, as they're the group of bones that hold your teeth in place and play an essential role in chewing and speaking.
Some key parts of the jaw include the maxilla (the upper jaw), mandible (the lower jaw), mandibular canal and mandibular foramen. If you're getting certain types of dental treatment like dental implants or jaw surgery, your oral surgeon or dentist might help you get to know the unique anatomy of your jaw.
Getting to Know Your Jaw
The human jaw consists of two bones. The maxilla is the bone that includes the roof of your mouth. It holds the upper teeth in place, many facial muscles are connected to it and help you to chew, smile and frown. The mandible is the lower bone. It holds the lower teeth in place and moves up and down whenever you open and close your mouth. The mandible attaches to the skull at the temporomandibular joint.
You'll find small openings, called foramen, at several points on the mandible. The mental foramen is one of two openings located on the anterior area of the front of the mandible. The mandibular foramen are located on either side of the interior part of the upper portion of the mandible in an area known as the ramus. (Encyclopaedia Britannica points out these features in a diagram.)
What Is a Foramen?
The simplest way to describe a foramen is as a hole in your jawbone. It's the entrance to the mandibular canal, which contains the inferior alveolar nerve, inferior alveolar artery and mental artery. This bundle of blood vessels and nerves travels through the canal, exiting the jawbone at the mental foramen.
The inferior alveolar nerve is the nerve that's responsible for providing sensation to your lower teeth. A dentist might use an inferior alveolar nerve block to help numb the lower jaw and make you feel more comfortable during certain dental procedures. The location of the injection site for that nerve block is near the mandibular foramen.
No Two Foramen Are Alike
While it's easy to think that the mandibular foramen is just an opening in the jawbone, it's a bit more interesting and complicated than that. There is considerable variation in the size and position of the foramen. The differences can be based on a person's age or their skull shape.
For example, a study published in Acta Odontologica Scandinavica suggests that the foramen moves upwards relative to the occlusal plane (an imaginary line located in the spot where your upper and lower teeth come together) as people age. A child's foramen is usually positioned lower than an adult's.
The Acta Odontologica Scandinavica study also notes that the location of the foramen could change based on the height of a person's face. Interestingly enough, a study in the Journal of Clinical and Diagnostic Research found that the mandibular foramen might be located in two different spots on opposite sides of the same person's jaw.
Why Is This Opening Important?
Why should you and your dentist care about the position and size of a hole in your lower jawbone? For one thing, it's essential that an oral surgeon know where the foramen is located when they perform surgery on the jawbone. It's also essential that a dentist know the location of the foramen before administering an inferior alveolar nerve block. As the Journal of Anatomy and Cell Biology notes, knowing the location and size of the foramen allows a dentist to choose an appropriately sized needle for administering a nerve block. Since the foramen leads to the canal that contains an important cranial nerve, the dentist or oral surgeon must know its location when placing dental implants.
In a nutshell, knowing where the mandibular foramen is located on each side of the lower jawbone can help a dentist or oral surgeon trace the location of the mandibular canal. The knowledge lets them avoid damaging the nerve during a surgery and can ensure that they can administer the appropriate amount of anesthetic in the right location.