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Tooth Reference

Dental Treatment Plan Decoder

Paste lines from your dental treatment plan, like “#30 MOD comp” or “SRP UR UL”. See each tooth, surface and abbreviation in plain English, with the tooth shown on a chart.

Example shown. Paste lines from your own plan.

One procedure per line, as written on your plan. Everything is decoded in your browser: nothing you paste is sent anywhere or saved. You can leave out your name and prices.

Tooth numbers on your plan

US dental offices use Universal numbers (1–32 for adult teeth, A–T for baby teeth). Charts from other countries often use FDI (11–48 and 51–85).

No text to paste? Build a line
1. Pick a tooth (optional)
UPPERLOWERPATIENT'S RIGHTLEFT1234567891011121314151632313029282726252423222120191817

Tap a tooth, or use the arrow keys and Enter.

2. Surfaces (fillings; optional)
3. Area (deep cleanings; optional)

Your line: (pick something above)

    Copy link shares only the decoded teeth, surfaces and terms. It never includes the text you pasted, procedure codes, prices or names.

    How to read a dental treatment plan

    Most plan lines follow the same pattern: which tooth, which surfaces, what procedure, sometimes followed by a code and a fee. "#30 MOD comp" means a tooth-colored (composite) filling on three surfaces of tooth 30, the lower right first molar.

    1. The tooth. A number (1–32) or a letter (A–T), often after "#". Some lines name an area instead, such as UR (upper right).
    2. The surfaces. Capital letters like MOD or DO. They appear for work on part of a tooth, such as fillings.
    3. The procedure. Shorthand like comp, PFM, RCT or SRP. The tool above explains more than 80 of these.

    If a word still makes no sense, ask the office before treatment starts.

    Tooth numbers in the US vs other countries

    US offices use the Universal system, which the ADA uses on its claim form. Adult teeth are numbered 1 to 32: tooth 1 is the upper right wisdom tooth, the numbers run across the upper jaw to 16, then drop to the lower left wisdom tooth (17) and run back to 32. Baby teeth are lettered A to T in the same order.

    International charts often use FDI (ISO 3950), the system the World Health Organization uses in its oral health surveys. Each tooth gets two digits: the quarter of the mouth (1–4 for adult teeth, 5–8 for baby teeth), then the position counting back from the middle (1–8 for adult teeth, 1–5 for baby teeth).

    ToothUniversalFDIPalmer
    Upper right wisdom tooth1188┘ (UR8)
    Upper left first molar1426└6 (UL6)
    Lower left first molar1936┌6 (LL6)
    Lower right first molar30466┐ (LR6)

    Watch out for numbers that exist in both systems. Tooth 14 is the upper left first molar in Universal, but the upper right first premolar in FDI. The same goes for 11 to 18, 21 to 28, 31 and 32, so the decoder warns you when a number could mean another tooth. Numbers like 36 or 46 can only be FDI, and in Universal, 51 to 82 mark extra (supernumerary) teeth. The Tooth Number Chart shows every tooth in all three systems.

    Plans also name quadrants, the four quarters of the mouth: UR (upper right), UL (upper left), LL (lower left) and LR (lower right). "SRP UR UL" means a deep cleaning of the upper right and upper left quarters.

    What MOD, DO and other surface letters mean

    The ADA claim form gives each surface of a tooth a one-letter code:

    LetterSurfaceWhere it is
    MMesialThe side facing the middle of the arch, toward your front teeth
    DDistalThe side toward the back of the mouth
    OOcclusalThe chewing surface of a back tooth
    IIncisalThe biting edge of a front tooth
    BBuccalThe cheek side of a back tooth
    FFacial (labial)The outer side, toward the lips or cheeks
    LLingualThe tongue side

    The letters are written together with no spaces. MOD is a filling that covers the mesial, occlusal and distal surfaces: one side, the top and the other side of a back tooth. DO covers the back side and the chewing surface, and MO the front side and the chewing surface. On a front tooth, MI or DI includes a corner of the biting edge. The order of the letters doesn't change the meaning. To see how long fillings usually last, try How Long Does Dental Work Last?

    What dental procedure codes are

    A capital D followed by four digits is a CDT code, from the American Dental Association's Code on Dental Procedures and Nomenclature. Federal HIPAA rules name it as the standard code set for dental services, so it appears on claims and many estimates. Each code has a short official name, and some have longer descriptions.

    The ADA owns the copyright to that wording, so this page doesn't list codes or their descriptions. The tool spots anything shaped like a code, and the office can tell you what it stands for.

    Black's cavity classes (Class I to VI)

    "Class II" on a plan usually refers to G.V. Black's classification, a system over 100 years old that sorts cavities and fillings by where they are on the tooth. Newer systems exist, but dental teams still learn it.

    ClassWhere
    IPits and grooves, mainly the chewing surface of back teeth
    IIA side of a back tooth (premolar or molar)
    IIIA side of a front tooth, not including the biting corner
    IVA side of a front tooth, including the biting corner
    VNear the gumline, on the cheek, lip or tongue side of any tooth
    VIThe biting edge of a front tooth or the tip of a cusp (added to Black's five classes later)

    So "#14 Class II amalgam" is a silver filling on a side of tooth 14, and an MOD or DO filling on a back tooth is usually called a Class II filling. Orthodontists also use Class I, II and III, but to describe how the upper and lower teeth meet.

    How this tool works

    1. It splits your text into lines and words. Prices, dates, percentages and code-like patterns are set aside first, so "245.00" is never read as a tooth.
    2. Tooth numbers are read in the system you choose (Universal unless you switch). A number that only exists in the other system is read in that system, and the tool says so. Palmer codes like UR6, baby tooth letters, lists ("#1, #16") and ranges ("#2-5") work too.
    3. Surfaces are groups of the letters M, O, D, B, L, F and I, with no letter repeated. A single letter next to a tooth number is read as a surface, while "ext K" is read as baby tooth K.
    4. Abbreviations are matched against our glossary, longest phrase first, so "comp exam" is an exam and "comp" alone is a composite filling. Each definition was checked against the sources below.
    5. Anything else is shown as "not recognized" rather than guessed.

    Limits: offices write shorthand in their own ways, and some abbreviations have two meanings ("max" can mean the upper jaw or your annual maximum). It can't tell you whether a treatment is right for you or what it will cost. For costs, try the Dental Insurance Calculator. For treatment day, see How long will I be numb? and When can I eat after dental work?

    Privacy: the text you paste stays in your browser. It isn't sent anywhere or saved. A copied link carries only the decoded tooth numbers, surface letters and glossary terms, never your text.

    Frequently asked questions

    What does MOD mean on a dental treatment plan?
    MOD lists the tooth surfaces the work covers: mesial (the side toward the front), occlusal (the chewing surface) and distal (the side toward the back). An MOD filling on a back tooth covers both sides and the top. In G.V. Black's system it's usually called a Class II filling.
    What do UR, UL, LR and LL mean?
    They are the four quadrants (quarters) of the mouth: upper right, upper left, lower right and lower left, from your point of view. "SRP UR UL" means scaling and root planing (a deep cleaning) of the upper right and upper left quarters.
    What do 4BWX and FMX mean?
    BWX are bitewing X-rays, which show the crowns (top parts) of the upper and lower teeth together, usually the back teeth. 4BWX means four bitewing pictures. FMX is a full-mouth series: usually 14 to 22 small X-rays that show every tooth down to the root tips. See how much radiation they involve.
    Is tooth 14 the same tooth everywhere?
    No. In the Universal system used in the US, tooth 14 is the upper left first molar. In the international FDI system (ISO 3950), 14 is the upper right first premolar (Universal 5). Numbers from 11 to 32 can mean different teeth in the two systems, so the decoder flags them. The Tooth Number Chart converts any number.
    What is a dental procedure code like a D with four numbers?
    It's a CDT code from the American Dental Association's Code on Dental Procedures and Nomenclature, the standard code set for dental claims in the US. The official wording is copyrighted by the ADA, so we don't list it. Ask the office what a code stands for.
    What is a Class II filling?
    In G.V. Black's cavity classes, Class II means a cavity or filling on a side surface of a back tooth (a premolar or molar), where it touches the next tooth. MO, DO and MOD fillings on back teeth are usually called Class II. In braces, Class II means something else: a bite where the upper teeth sit well ahead of the lower teeth.

    Sources

    1. American Dental Association. Glossary of Dental Terms (administrative and clinical terms). Accessed October 26, 2026.
    2. American Dental Association. ADA Dental Claim Form Completion Instructions, Version 2024 (items 26–28: tooth system, tooth numbers, tooth surfaces). 2023. Accessed October 26, 2026.
    3. American Dental Association. ADA Dental Claim Form (tooth designation systems). Accessed October 26, 2026.
    4. World Health Organization. Oral health surveys: basic methods, 5th edition (tooth notation after ISO 3950). 2013. Accessed October 26, 2026.
    5. American Dental Association. The Code on Dental Procedures and Nomenclature (CDT Code). Accessed October 26, 2026.
    6. Legal Information Institute, Cornell Law School. 45 CFR § 162.1002 – Medical data code sets. Accessed October 26, 2026.
    7. Centers for Medicare & Medicaid Services (Medicare Learning Network). American Dental Association: Current Dental Terminology (license terms for CMS use). Accessed October 26, 2026.
    8. American Association of Endodontists. Glossary of Endodontic Terms, Tenth Edition. 2020. Accessed October 26, 2026.
    9. Budisak P, Brizuela M. StatPearls (NCBI Bookshelf). Dental Caries Classification Systems. last update November 12, 2023. Accessed October 26, 2026.
    10. DentistryIQ (Jeong C, RDH). Must-know classifications of dental caries for the national dental hygiene boards. 2016, reviewed 2022. Accessed October 26, 2026.
    11. Cleveland Clinic. Dental Fillings: Types, Materials & What They're For. last updated May 13, 2024. Accessed October 26, 2026.
    12. Cleveland Clinic. Dental Crowns: Types, Procedure & Care. last updated April 14, 2023. Accessed October 26, 2026.
    13. Cleveland Clinic. Dental Bridges: Types & Who Needs Them. last updated May 24, 2023. Accessed October 26, 2026.
    14. Boston University Henry M. Goldman School of Dental Medicine. Dental Bridge. Accessed October 26, 2026.
    15. Cleveland Clinic. Periodontics / Periodontist. last updated June 30, 2022. Accessed October 26, 2026.
    16. Cleveland Clinic. Veneers: What Are Dental Veneers?. last updated July 18, 2022. Accessed October 26, 2026.
    17. Cleveland Clinic. Dental Bonding & What To Expect. last updated January 5, 2026. Accessed October 26, 2026.
    18. Cleveland Clinic. Root Canal: Procedure & Recovery. last updated September 15, 2026. Accessed October 26, 2026.
    19. Cleveland Clinic. Dental Cleaning. last updated January 5, 2026. Accessed October 26, 2026.
    20. Cleveland Clinic. Tooth Scaling and Root Planing (Dental Deep Cleaning). last updated December 2, 2024. Accessed October 26, 2026.
    21. Cleveland Clinic. Sealants. last updated March 27, 2023. Accessed October 26, 2026.
    22. American Dental Association. Fluoride: Topical and Systemic Supplements (Oral Health Topics). updated June 14, 2023. Accessed October 26, 2026.
    23. Cleveland Clinic. Bruxism (Teeth Grinding): Symptoms, Causes & Treatment. last updated December 18, 2023. Accessed October 26, 2026.
    24. Cleveland Clinic. Dental X-rays: Purpose & Types. last updated August 16, 2025. Accessed October 26, 2026.
    25. American Dental Association. X-Rays/Radiographs (Oral Health Topics). updated March 26, 2026. Accessed October 26, 2026.
    26. Gloucestershire Hospitals NHS Foundation Trust (Oral and Maxillofacial). Advice for patients having a tooth removed (GHPI0792_03_25). content reviewed March 2025. Accessed October 26, 2026.
    27. Cleveland Clinic. Wisdom Teeth Removal: Procedure & Recovery. last updated August 11, 2026. Accessed October 26, 2026.
    28. Cleveland Clinic. Impacted Tooth: Types, Symptoms & Treatment. last updated June 21, 2024. Accessed October 26, 2026.
    29. Cleveland Clinic. Dental Bone Graft: Process, Purpose & Healing. last updated August 6, 2024. Accessed October 26, 2026.
    30. Cleveland Clinic. Dental Implants: Types, Purpose & Benefits. last updated June 11, 2026. Accessed October 26, 2026.
    31. Cleveland Clinic. What Are Dentures? Types, Care & Benefits. last updated March 10, 2023. Accessed October 26, 2026.
    32. American Academy of Pediatric Dentistry. Pediatric Restorative Dentistry (Reference Manual of Pediatric Dentistry). latest revision 2022. Accessed October 26, 2026.
    33. American Dental Association (MouthHealthy). Nitrous Oxide – Laughing Gas. Accessed October 26, 2026.
    34. Cleveland Clinic. Malocclusion (Misaligned Bite): Types & Treatment. last updated October 28, 2024. Accessed October 26, 2026.
    35. American Dental Association. Dental Benefits: An Introduction. 2024. Accessed October 26, 2026.
    36. ADA News. Dear ADA: Annual maximums. December 19, 2025. Accessed October 26, 2026.

    Last reviewed by the Dental Health Time editorial team, against the sources above. How we review.

    Tooth Number ChartConvert Universal, FDI and Palmer tooth numbers How Long Dental Work LastsHow long crowns, fillings and implants last Insurance CalculatorPlan pays vs. you pay, item by item Numbness CalculatorWhen will my lip stop being numb?