Patients regularly arrive convinced they need a root canal and leave having been told to treat a sinus infection. The confusion is completely reasonable. The roots of your upper molars sit directly against the floor of the maxillary sinus, sometimes with less than a millimeter between them, and pressure on one side of that wall is felt on the other.
What a Toothache Usually Feels Like
- Pain you can point to with one finger
- Sharp rather than dull, and often throbbing
- A strong reaction to hot or cold that lingers after the stimulus is gone
- Pain when you bite down on that specific tooth
- Steady regardless of how you move your head
What Sinus Pain Usually Feels Like
- Dull pressure across several upper teeth at once rather than one
- Fullness under the cheekbones, often behind the eyes and across the forehead
- Worse when you bend forward or lie down
- Congestion, postnasal drip, or a recent cold
- Frequently on both sides
Four Tests You Can Do at Home
- Bend forward and hold for a few seconds. Worse means sinus. Unchanged means tooth.
- Tap each upper tooth gently with a fingernail. One tooth that stands out means a dental cause.
- Try cold water on the area. A lingering jolt on one tooth points to the nerve.
- Count the teeth involved. Three or four aching together is more typical of sinus pressure than of a single infected tooth.
Why It Is Worth Getting Right
Because it runs both ways. Sinus pressure can imitate a toothache, and an infected upper molar can seed a genuine sinus infection. There is a well documented pathway there, which is why a sinus infection that keeps returning on one side is worth having a dentist look at.
When to Call Us Rather Than Wait
- Pain isolated to one tooth, particularly if it wakes you at night
- Swelling in the face or gum
- Fever alongside dental pain
- A tooth that has darkened or become loose
- Sinus pain that has persisted more than ten days, or keeps returning to the same side
If you are not sure, call and describe it. Working that out over the phone takes a couple of minutes and saves you a week of guessing. Our emergency dentistry page explains how same day visits work.