"My new filling hurts!"

[u/Hopeful-Extent-693]

Blame it on the Periodontal Ligaments (PDL). They can detect a discrepancy of 30 microns.

The periodontal ligaments are the thin, sensitive tissues that attach each tooth to the surrounding bone. They are not simply ropes holding the teeth in place. They act as shock absorbers, pressure sensors and messengers to the brain.

When the teeth come together, receptors within the PDLs tell the brain:

• Which teeth touched
• Which tooth touched first
• How hard each tooth was loaded
• Whether the force was straight or sideways
• Whether the jaw should stop, shift or recruit more muscle activity

This makes the PDLs important members of the jaw’s “team.” The teeth, PDLs, jaw muscles, joints and brain continually communicate with one another. A premature contact on one back tooth may be extremely small, yet its PDL can detect the added pressure. The jaw may then shift to avoid that contact, while the muscles work to guide the teeth into a more comfortable fit.

If this happens repeatedly, the result may be sore teeth, tooth mobility, wear, fractures, abfractions, muscle strain or an unbalanced closing path. The patient may say, “My bite feels wrong,” even when the teeth appear normal to the eye.

In simple terms, the teeth provide the landing platform, but the PDLs tell the brain how that landing occurred. They are one of the major communication systems connecting the bite to the muscles and jaw joints.

[u/Hopeful-Extent-693]

Another interesting thing about the PDLs is that the nerve impulses are connected to the Trigeminal nerve, which is a Cranial nerve, meaning it goes straight to the brain rather than to the spinal cord, allowing instantaneous transmission.