Tooth Notation Explained

If you have been handed a treatment plan that mentions the LL7 or the UR6, it is describing one specific tooth. Dentists use shorthand for this because saying “the second molar in the lower left quadrant” every time is impractical. Here is how to read it.

The letters are the quadrant

Your mouth is divided into four quarters, and the two letters tell you which one, always from your own perspective rather than the viewer’s:

• UR — upper right
• UL — upper left
• LL — lower left
• LR — lower right

The number is the position from the middle

Within each quadrant, adult teeth are numbered 1 to 8, counting outwards from the midline at the front of your mouth. So the 1 is a front tooth and the 8 is a wisdom tooth.

Put together: LL7 is the second molar in your lower left quadrant. UR6 is the first molar in your upper right. UL1 is your upper left front tooth.

The same tooth in two notation systems

The lettered form above is Palmer notation, which is what we use in our clinical records and case library. You may also see the FDI two-digit system, used internationally and in most dental software, where the first digit is the quadrant and the second is the tooth. The table below gives the FDI number for every adult tooth.

So the LL7 is tooth 37 in FDI notation. The UR6 is 16. Children’s teeth use a separate set of codes, lettered A–E in Palmer notation and numbered 51–85 in FDI.

Reading your own treatment plan

A written plan will normally pair each tooth with the treatment proposed for it, so “LL7 — root canal treatment” means one specific molar in your lower left. If a plan you have been given is not clear, ask whoever produced it to point to the tooth in your mouth or on your radiograph. Any dentist will be happy to do this, and it is worth asking rather than guessing.

Cases treated at the practice

Our endodontic case library is catalogued using this notation, and is written for referring dentists. If you are curious what treatment on a particular tooth involves, these are real cases with pre- and post-operative radiographs:

• LL7 primary root canal treatment — lower left second molar
• LL7 retreatment — a tooth referred for extraction and saved
• UR6 with a missed MB2 canal — upper right first molar
• UL1 with a sclerosed canal — upper left central incisor

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