Surface letters
Every surface finding starts with these letters. On a premolar or molar the chewing surface is occlusal and the cheek side is buccal; on an incisor or canine the edge is incisal and the lip side is facial. Some charts use F for the outer surface of every tooth and P, palatal, for the inside of upper teeth.
| Letter | Surface |
|---|---|
| M | mesial |
| O | occlusal |
| I | incisal |
| D | distal |
| B | buccal |
| F | facial |
| L | lingual |
Combined codes follow a fixed order: the proximal surface first, the biting surface next, distal last when both proximal surfaces are involved, then buccal or facial, then lingual. That is why you see MO, DO, MOD and MODBL, and never OD. The surface order guide walks through it step by step.
Materials, conditions and their symbols
The table lists every finding a ChartCall callout can name, with the abbreviation you will see written, the colour it is charted in, and how the odontogram draws it. Paper charts in your program may use a slightly different mark for the same finding, but the idea is the same: surface findings are filled in on the surfaces they cover, and whole tooth findings are drawn across the tooth outline or its roots.
| Abbreviation | Meaning | Colour | Drawn in ChartCall as |
|---|---|---|---|
| Am | Amalgam | Blue, existing | Surfaces filled in solid |
| Comp | Composite | Blue, existing | Surfaces hatched |
| GI | Glass ionomer | Blue, existing | Surfaces dotted |
| Au inlay | Gold inlay or onlay | Blue, existing | Surfaces cross hatched |
| Temp | Temporary filling | Blue, existing | Surfaces outlined only |
| Car | Caries | Red, needed | Surfaces filled in solid |
| Rec car | Recurrent caries | Red, needed | Surfaces hatched |
| PFM | Porcelain fused to metal crown | Blue, existing | Crown outlined |
| FGC | Full gold crown | Blue, existing | Crown outlined |
| Cer | All ceramic crown | Blue, existing | Crown outlined |
| SSC | Stainless steel crown | Blue, existing | Crown outlined |
| X | Missing | Blue, existing | Large X through the whole tooth |
| Ext | Extraction indicated | Red, needed | Two parallel lines through the tooth |
| RCT | Root canal treatment | Blue, existing | Line down each root |
| Imp | Implant | Blue, existing | Short horizontal lines across the root, like screw threads |
| S | Sealant | Blue, existing | Letter S on the biting surface |
| W | Watch | Red, needed | Letter W on the tooth |
| Pontic | Bridge pontic | Blue, existing | Crown outlined, root crossed out |
| Pulp | Pulpotomy | Blue, existing | Dot in the pulp chamber |
| Fx | Fractured tooth | Red, needed | Zigzag across the crown |
Red and blue: existing work and needed work
The most useful symbol on a chart is its colour. A common convention charts what is already in the mouth, existing fillings, crowns, implants and root canals, in blue or black, and what still needs doing, decay, recurrent decay, a fracture or a tooth to be extracted, in red. When the red work is completed it is charted again in blue. The treatment plan is then the red on the chart. Because some readers cannot tell red from blue, ChartCall also gives every mark its own shape, and so should any chart you design.
Worked example: reading one written entry
Suppose a chart shows #30 MOD Am in blue and #30 DB Car in red. Read it part by part. #30 is the lower right first molar in Universal numbering. MOD Am in blue is an existing amalgam filling across the mesial, occlusal and distal surfaces, drawn solid on those three surfaces. DB Car in red is decay on the distal and buccal surfaces that still needs treatment. Spoken aloud chairside, those two entries would be "number 30, MOD amalgam" and "30, DB caries". Two findings on one tooth are charted separately, each with its own colour.
Common mistakes
- Writing a three surface filling as three fillings, M, O and D, instead of one MOD restoration.
- Writing OD or OM. The proximal surface leads: DO and MO.
- Using O or B on a front tooth. Incisors and canines take I and F.
- Charting a missing tooth and a tooth planned for extraction with the same X. One is gone; the other is present and red.
- Reading GI as gingival index on a human chart. On a human chart GI is glass ionomer; on a veterinary chart it is the gingival index.
- Leaving recurrent decay under an existing filling as plain caries, which hides the failing restoration.
Veterinary chart abbreviations
Dog and cat charts add grades and conditions that human charts rarely use: mobility, furcation, calculus and gingival indices, tooth resorption stages and fracture types. Most are written as an abbreviation plus the grade, such as MOB2 or TR3, beside the tooth. Numbering is modified Triadan; see the Triadan numbering guide.
| Abbreviation | Meaning | Colour | Drawn in ChartCall as |
|---|---|---|---|
| MOB1 | Mobility 1 | Red, needed | Written as a tag beside the tooth |
| MOB2 | Mobility 2 | Red, needed | Written as a tag beside the tooth |
| MOB3 | Mobility 3 | Red, needed | Written as a tag beside the tooth |
| F1 | Furcation 1 | Red, needed | Written as a tag beside the tooth |
| F2 | Furcation 2 | Red, needed | Written as a tag beside the tooth |
| F3 | Furcation 3 | Red, needed | Written as a tag beside the tooth |
| CI1 | Calculus index 1 | Red, needed | Written as a tag beside the tooth |
| CI2 | Calculus index 2 | Red, needed | Written as a tag beside the tooth |
| CI3 | Calculus index 3 | Red, needed | Written as a tag beside the tooth |
| GI1 | Gingival index 1 | Red, needed | Written as a tag beside the tooth |
| GI2 | Gingival index 2 | Red, needed | Written as a tag beside the tooth |
| GI3 | Gingival index 3 | Red, needed | Written as a tag beside the tooth |
| GR | Gingival recession | Red, needed | Surfaces hatched |
| CCF | Complicated crown fracture | Red, needed | Zigzag across the crown with a dot for the exposed pulp |
| UCF | Uncomplicated crown fracture | Red, needed | Zigzag across the crown |
| AT or AB | Worn tooth | Red, needed | Written as a tag beside the tooth |
| CA | Caries | Red, needed | Surfaces filled in solid |
| DT | Discoloured tooth | Red, needed | Written as a tag beside the tooth |
| EH | Enamel hypoplasia | Red, needed | Written as a tag beside the tooth |
| TR1 | Tooth resorption stage 1 | Red, needed | Written as a tag beside the tooth |
| TR2 | Tooth resorption stage 2 | Red, needed | Written as a tag beside the tooth |
| TR3 | Tooth resorption stage 3 | Red, needed | Written as a tag beside the tooth |
| TR4 | Tooth resorption stage 4 | Red, needed | Written as a tag beside the tooth |
| TR5 | Tooth resorption stage 5 | Red, needed | Written as a tag beside the tooth |
| O | Missing tooth | Blue, existing | Circle around the tooth |
| X | Extracted | Blue, existing | Large X through the whole tooth |
| RTR | Retained root | Red, needed | Written as a tag beside the tooth |
| RD | Retained deciduous tooth | Red, needed | Written as a tag beside the tooth |
| SN | Supernumerary tooth | Red, needed | Written as a tag beside the tooth |
| CR | Prosthetic crown | Blue, existing | Crown outlined |
| R | Composite restoration | Blue, existing | Surfaces cross hatched |
| RCT | Root canal treatment | Blue, existing | Line down each root |
Every entry here has a longer definition, and the other words an operator may say for it, in the dental charting glossary. To hear these abbreviations spoken and chart them against the clock, try the free daily charting drill.
Sources
Checked against these sources on 26 September 2026. Conventions differ between schools, offices and clinics; where yours differ, follow your program.
- Dental assisting textbooks. The charting chapters of the standard dental assisting texts used in accredited programs, such as Modern Dental Assisting (Elsevier), which describe surface letters, red and blue charting and the common symbols.
- Black's cavity classification. The class I to V grouping of cavities by location, with class VI added later, which still shapes how surfaces are named and combined.
- American Veterinary Dental College, abbreviations for use in case logs. The published list of veterinary dental abbreviations that clinics and teaching programs commonly adapt, used here for the veterinary table.