Reviewed by the toothcheck Dental Team Independent dentist providing online second opinions.Reviewed by the toothcheck Dental Team Independent dentist providing online second opinions.

Understanding Your Dental X-Ray Report and Chart Notes

You asked for a copy of your records and got back a page of abbreviations: "BW WNL," "#3 MOD recurrent caries," "#19 PARL, RCT?", "watch #14." It reads like code because, in a sense, it is - dental charting is a compact shorthand dentists use to note findings quickly. The good news is that once you know the handful of abbreviations that come up again and again, your report becomes readable.You asked for a copy of your records and got back a page of abbreviations: "BW WNL," "#3 MOD recurrent caries," "#19 PARL, RCT?", "watch #14." It reads like code because, in a sense, it is - dental charting is a compact shorthand dentists use to note findings quickly. The good news is that once you know the handful of abbreviations that come up again and again, your report becomes readable.

This guide decodes the notes and abbreviations you are most likely to see. It is the companion to our dental X-ray interpretation guide, which explains what the images themselves show - this one explains the written words around them.

Quick Answer

Dental notes mix three things: the type of X-ray (BW = bitewing, PA = periapical, PAN = panoramic, FMX = full-mouth series, CBCT = 3D scan), the tooth and surfaces involved (a number 1 to 32 plus letters like M, O, D for the sides of the tooth), and the finding itself (WNL = within normal limits, "watch" = monitor rather than treat now, recurrent caries = new decay around an old filling, PARL = a dark area at a root tip, RCT = root canal). A note is a finding, not automatically a treatment order - and you have a right to a written copy explained in plain language.Dental notes mix three things: the type of X-ray (BW = bitewing, PA = periapical, PAN = panoramic, FMX = full-mouth series, CBCT = 3D scan), the tooth and surfaces involved (a number 1 to 32 plus letters like M, O, D for the sides of the tooth), and the finding itself (WNL = within normal limits, "watch" = monitor rather than treat now, recurrent caries = new decay around an old filling, PARL = a dark area at a root tip, RCT = root canal). A note is a finding, not automatically a treatment order - and you have a right to a written copy explained in plain language.

X-Ray Types (What Kind of Image It Was)

The report usually starts by naming the images taken. Each type shows something different.The report usually starts by naming the images taken. Each type shows something different.

• BW - bitewing. Shows the crowns of the upper and lower back teeth together. Best for spotting decay between teeth and checking bone levels. The most common routine X-ray.BW - bitewing. Shows the crowns of the upper and lower back teeth together. Best for spotting decay between teeth and checking bone levels. The most common routine X-ray.
• PA - periapical. Shows one or two whole teeth from the biting surface down to the root tip. Used to investigate a specific tooth, its root, and the bone around it.PA - periapical. Shows one or two whole teeth from the biting surface down to the root tip. Used to investigate a specific tooth, its root, and the bone around it.
• PAN - panoramic. A single wide image of the whole jaw. Good for wisdom teeth, overall structure, and large-scale problems, but less detailed for small cavities.PAN - panoramic. A single wide image of the whole jaw. Good for wisdom teeth, overall structure, and large-scale problems, but less detailed for small cavities.
• FMX or FMS - full-mouth series. A complete set of individual X-rays covering every tooth. Usually taken every few years.FMX or FMS - full-mouth series. A complete set of individual X-rays covering every tooth. Usually taken every few years.
• Occlusal. A larger film showing the roof or floor of the mouth, used less often.Occlusal. A larger film showing the roof or floor of the mouth, used less often.
• CBCT - cone beam CT. A 3D scan, reserved for specific situations like implant planning, impacted teeth near a nerve, or suspected root fractures.CBCT - cone beam CT. A 3D scan, reserved for specific situations like implant planning, impacted teeth near a nerve, or suspected root fractures.

Tooth and Surface Notation (Where the Finding Is)

Findings are pinned to an exact spot using two things: a tooth number and surface letters.Findings are pinned to an exact spot using two things: a tooth number and surface letters.

Tooth numbers. In the US, teeth are numbered 1 to 32 (baby teeth are lettered A to T). If you are unsure which tooth a number refers to, our tooth numbering guide maps every one - for example, #14 is the upper left first molar and #30 is the lower right first molar.

Surface letters. A tooth has five named surfaces, and fillings are described by which ones are involved:Surface letters. A tooth has five named surfaces, and fillings are described by which ones are involved:

• M - mesial (the side toward the front midline)M - mesial (the side toward the front midline)
• D - distal (the side toward the back)D - distal (the side toward the back)
• O - occlusal (the biting surface of a back tooth)O - occlusal (the biting surface of a back tooth)
• B - buccal or F - facial (the cheek/lip side)B - buccal or F - facial (the cheek/lip side)
• L - lingual (the tongue side)L - lingual (the tongue side)

So "MO" means two surfaces (mesial and occlusal), and "MOD" means three (mesial, occlusal, distal). More surfaces generally means a larger restoration. A note like "#3 MOD composite" simply means a three-surface tooth-colored filling on the upper right first molar.So "MO" means two surfaces (mesial and occlusal), and "MOD" means three (mesial, occlusal, distal). More surfaces generally means a larger restoration. A note like "#3 MOD composite" simply means a three-surface tooth-colored filling on the upper right first molar.

Finding and Status Shorthand (What They Saw)

This is the part patients most want translated. These are the notes that describe the actual findings.This is the part patients most want translated. These are the notes that describe the actual findings.

• WNL - within normal limits. That area looks normal and healthy. Reassuring.WNL - within normal limits. That area looks normal and healthy. Reassuring.
• NAD - no abnormality detected. Similar to WNL - nothing concerning found.NAD - no abnormality detected. Similar to WNL - nothing concerning found.
• "watch" (sometimes WL, or "monitor"). A spot that is not bad enough to treat yet. The dentist will keep an eye on it over time rather than drilling now. This is a normal, conservative approach, common for early decay."watch" (sometimes WL, or "monitor"). A spot that is not bad enough to treat yet. The dentist will keep an eye on it over time rather than drilling now. This is a normal, conservative approach, common for early decay.
• Caries / decay. A cavity. Often written with the tooth and surface, e.g. "distal caries #12."Caries / decay. A cavity. Often written with the tooth and surface, e.g. "distal caries #12."
• Recurrent (or secondary) caries. New decay at the edge of an existing filling or crown - a common, legitimate reason to replace a restoration.Recurrent (or secondary) caries. New decay at the edge of an existing filling or crown - a common, legitimate reason to replace a restoration.
• Incipient / early caries. Early decay still in the enamel, frequently a "watch" rather than an immediate filling.Incipient / early caries. Early decay still in the enamel, frequently a "watch" rather than an immediate filling.
• PARL / PARP - periapical radiolucency. A dark area on the X-ray at the tip of a root, which can indicate infection from a dead or infected nerve. It is a finding that needs interpretation in context - not always urgent, but worth understanding. Our guide on signs you need a root canal explains when it matters.
• RCT. Root canal treatment. On a plan it may mean a root canal is recommended; in a history it may mean one was already done. A question mark ("RCT?") usually means the dentist is flagging it as a possibility to investigate.RCT. Root canal treatment. On a plan it may mean a root canal is recommended; in a history it may mean one was already done. A question mark ("RCT?") usually means the dentist is flagging it as a possibility to investigate.
• Calculus / calc. Hardened tartar, often noted with its location above or below the gumline.Calculus / calc. Hardened tartar, often noted with its location above or below the gumline.
• Bone loss (horizontal / vertical). Reduced bone support around teeth, a sign of periodontitis. If you see this alongside gum-pocket numbers, our guide on verifying a gum disease diagnosis is worth a read.
• Impaction. A tooth, often a wisdom tooth, blocked from coming in fully.Impaction. A tooth, often a wisdom tooth, blocked from coming in fully.
• Retained root / root tip. A fragment of root left in the bone after a tooth was lost or extracted.Retained root / root tip. A fragment of root left in the bone after a tooth was lost or extracted.
• Existing restorations. Notes like "amalgam," "composite," "crown," or "PFM" simply record work already present, so it is not mistaken for a new problem.Existing restorations. Notes like "amalgam," "composite," "crown," or "PFM" simply record work already present, so it is not mistaken for a new problem.

Perio Chart Numbers (The Gum Measurements)

If your records include a periodontal chart, you will see rows of small numbers - usually several per tooth. These are pocket depths in millimeters, measured between the gum and the tooth:If your records include a periodontal chart, you will see rows of small numbers - usually several per tooth. These are pocket depths in millimeters, measured between the gum and the tooth:

• 1 to 3 mm is generally healthy.1 to 3 mm is generally healthy.
• 4 mm and above, especially with bleeding, is where concern begins.4 mm and above, especially with bleeding, is where concern begins.

You may also see BOP (bleeding on probing) noted. These measurements are the objective basis for a gum-disease diagnosis, which is why it is reasonable to ask to see them before agreeing to a deep cleaning.You may also see BOP (bleeding on probing) noted. These measurements are the objective basis for a gum-disease diagnosis, which is why it is reasonable to ask to see them before agreeing to a deep cleaning.

A Finding Is Not Automatically a Treatment

The most useful thing to remember: a note records what the dentist observed, which is not the same as a diagnosis, which in turn is not the same as a treatment decision. "PARL #19" is an observation. Whether it means you need a root canal depends on the diagnosis behind it and your symptoms. "Watch #14" explicitly means no treatment yet. When a note jumps straight to a costly recommendation without an observation you can see, that is a fair thing to ask about. To connect the notes to the prices you were quoted, see how to read your dental treatment plan, and for any word still unclear, the plain-English dental glossary has it.

Your Right to the Report - and to Have It Explained

Under HIPAA you have a right to your dental records, including your X-rays and the written notes. You are also entitled to have them explained in language you understand - it is completely reasonable to ask your dentist to walk through the report with you. Guidance from bodies like the American Academy of Oral and Maxillofacial Radiology underpins how imaging is interpreted and reported.

FAQ

What does WNL mean on my dental chart? WNL stands for "within normal limits" - the area looked normal and healthy, with nothing concerning found. NAD ("no abnormality detected") means much the same thing.What does WNL mean on my dental chart? WNL stands for "within normal limits" - the area looked normal and healthy, with nothing concerning found. NAD ("no abnormality detected") means much the same thing.

What does it mean when a tooth is marked "watch"? It means the finding is too early or too minor to treat now, so the dentist will monitor it at future visits rather than drilling immediately. It is a normal, conservative approach, most often used for early enamel decay.What does it mean when a tooth is marked "watch"? It means the finding is too early or too minor to treat now, so the dentist will monitor it at future visits rather than drilling immediately. It is a normal, conservative approach, most often used for early enamel decay.

What is a PARL on a dental X-ray? PARL stands for periapical radiolucency - a dark area at the tip of a tooth root that can indicate infection from a dead or infected nerve. It is a finding that needs interpretation in context; some are urgent and some are stable, so it is worth asking what it means for your specific tooth.What is a PARL on a dental X-ray? PARL stands for periapical radiolucency - a dark area at the tip of a tooth root that can indicate infection from a dead or infected nerve. It is a finding that needs interpretation in context; some are urgent and some are stable, so it is worth asking what it means for your specific tooth.

What is the difference between a bitewing and a periapical X-ray? A bitewing (BW) shows the crowns of the upper and lower back teeth together and is best for decay between teeth. A periapical (PA) shows one or two whole teeth from crown to root tip and is used to investigate a specific tooth and its root.What is the difference between a bitewing and a periapical X-ray? A bitewing (BW) shows the crowns of the upper and lower back teeth together and is best for decay between teeth. A periapical (PA) shows one or two whole teeth from crown to root tip and is used to investigate a specific tooth and its root.

What do MO, DO, and MOD mean on a filling? They are the tooth surfaces involved. M is mesial, O is occlusal, D is distal, so MO means two surfaces, DO means two, and MOD means three. More surfaces generally means a larger filling.What do MO, DO, and MOD mean on a filling? They are the tooth surfaces involved. M is mesial, O is occlusal, D is distal, so MO means two surfaces, DO means two, and MOD means three. More surfaces generally means a larger filling.

Can I get a copy of my written X-ray report and notes? Yes. Under HIPAA you have a right to your records, including X-rays and chart notes, usually at little or no cost. You can also ask your dentist to explain the report in plain language, which is a completely reasonable request.Can I get a copy of my written X-ray report and notes? Yes. Under HIPAA you have a right to your records, including X-rays and chart notes, usually at little or no cost. You can also ask your dentist to explain the report in plain language, which is a completely reasonable request.

Final Advice

A dental report only looks like code until you know the vocabulary. Once you can tell an image type from a surface from a finding, you can read your own notes and see exactly what was observed - and, just as importantly, what was marked to watch rather than treat.A dental report only looks like code until you know the vocabulary. Once you can tell an image type from a surface from a finding, you can read your own notes and see exactly what was observed - and, just as importantly, what was marked to watch rather than treat.

If your report still leaves you unsure, or a note has turned into a big recommendation you do not fully follow, you can have it read for you. Upload your X-rays and notes to toothcheck for a plain-English independent second opinion, and a licensed dentist will walk through the findings and what they mean in writing, usually in under 72 hours. If it is a full plan you want checked, start with a dental treatment plan review.

Last medically reviewed: July 2026Last medically reviewed: July 2026