Tooth #3 in particular
About the upper right first molar
Tooth 3 is the upper right first molar: sixth from the midline, with the second premolar, tooth 4, in front and the second molar, tooth 2, behind. Dentists outside the US may write it as 16 (FDI) or UR6 (Palmer). It bites against tooth 30, the lower right first molar, and that pair handles much of the chewing on the right side. First molars are the largest teeth. They are also the first permanent teeth to arrive, typically at 6 to 7 years, appearing behind the baby teeth instead of pushing one out. Parents sometimes assume a new back tooth at that age is another baby tooth. Tooth 3 typically has three roots, and four canals are common because one root often holds two.
What tends to go wrong here
The history of tooth 3 explains most of what goes wrong with it. It erupts into the mouth of a six-year-old, with deep grooves on its chewing surface and a child doing the brushing, so decay often starts early. That is why dentists commonly seal the grooves of first molars in childhood. By adulthood many of these teeth carry an old filling, and first molars are the teeth most often filled, crowned and root-canal treated over a lifetime. A large, aging filling can leak at its edges or leave a cusp unsupported. On the upper right, an infection at the roots can also show up as sinus-like symptoms on that side, because upper molar roots lie close to the maxillary sinus.
If it needs treatment
What makes tooth 3 different to treat is the combination of several canals and a sinus overhead. During a root canal the dentist looks for a fourth canal, since one of the three roots often has two, and a missed canal is a known reason for treatment to fail. Afterward a crown is usually recommended, as on any molar. Extractions are planned with the sinus in mind. If a filling, crown or root canal is proposed, ask how much natural tooth is left under the existing filling, whether a crown now would protect it, who will carry out a root canal if one is needed, and what the x-ray shows about the roots and the sinus.
What it does
What the upper right first molar is for
First molars are the largest teeth and do most of the grinding. They are the first permanent teeth to arrive, behind the baby teeth, without replacing any of them. Often called the "six-year molars".
Anatomy
Roots and canals of tooth #3
Typically three roots. Four canals are common, because one root often has two. These are typical patterns. The only way to know the anatomy of your own tooth is an x-ray, which is why one is taken before a root canal or extraction.
Common problems
What tends to go wrong with first molars
Because they arrive around age six and have deep grooves, first molars are the teeth most often filled, crowned, and root-canal treated over a lifetime.
If it needs treatment
Root canal, crown, or extraction on tooth #3
Upper molar roots lie close to the maxillary sinus, so infections can cause sinus-like symptoms and extractions are planned with that in mind. A crown is usually recommended after a root canal on a molar.
| Root canal: what to expect |
| Tooth extraction: what to expect |
| Dental crown: what to expect |
| Extraction or root canal? |
General information · Not dental advice
This page describes a typical first molar. It cannot tell you anything about your own tooth #3. We always recommend seeing a dentist. Nothing on this site can examine your mouth or tell you what is wrong. If something hurts, looks wrong, or worries you, book an exam, and go sooner if it is getting worse.
Emergency? If you have trouble breathing or swallowing, swelling that is spreading toward your eye or neck, a fever with facial swelling, or bleeding that will not stop, call 911 or go to your nearest emergency room immediately. Full disclaimer