Step by step
- Find the tooth first. Put your pointer on the tooth number before you think about surfaces. A perfect surface code on the wrong tooth is still a wrong entry.
- Decide whether it is a front or a back tooth. Back teeth (premolars and molars) have an occlusal surface, O, and a buccal surface, B. Front teeth (incisors and canines) have an incisal edge, I, and a facial surface, F.
- Mark every surface you heard. Tick each surface named in the callout on the tooth diagram. Treat a spelled group such as M O D as one restoration covering all three.
- Write the proximal surface first. Start with mesial when it is present. If only distal is involved, start with distal instead, so the code is DO and never OD.
- Add the biting surface, then distal. Next comes O on a back tooth or I on a front tooth, then D if both proximal surfaces are involved, which gives MO, DO and MOD.
- Finish with the outer and inner surfaces. Add B or F, then L, at the end: MODB, MODL, MODBL. Then chart the material or condition that goes with the code.
Why the order matters
A chart is read by other people: the dentist planning treatment, the front desk building a claim, the next clinician at recall. If every recorder writes the same filling the same way, nobody has to stop and work out whether OMD and MOD are the same restoration. The order also mirrors the tooth. Mesial faces the midline of the arch, the occlusal surface is in the middle, and distal faces away from the midline, so MOD reads across the tooth from front to back.
Operators do not always say the surfaces in written order. They say what they see as they see it, and you hear "occlusal distal" or "distal occlusal" for the same filling. Your job is to mark the surfaces, then write the code in the standard order, whatever order you heard.
Front teeth and back teeth
Back teeth, the premolars and molars, have five surfaces: mesial (M), occlusal (O), distal (D), buccal (B) and lingual (L). Front teeth, the incisors and canines, have an edge instead of a chewing surface and a lip side instead of a cheek side, so O becomes incisal (I) and B becomes facial (F). A front tooth filling across the mesial surface and the incisal edge is MI, and the common class IV restoration is MI or DI plus the facial or lingual surface it wraps onto. In the ChartCall drill, marking O on an incisor is read as I, so the back tooth letter is never marked wrong on a front tooth.
Worked examples
Each callout below is said in the order an operator might say it. The last column is the code you write, computed by the same rule the daily drill grades with.
| Callout as heard | Tooth | Written code |
|---|---|---|
| Number 3, mesial occlusal distal amalgam | 3, upper right first molar | MOD |
| 14, occlusal distal composite | 14, upper left first molar | DO |
| Number 19, occlusal mesial caries | 19, lower left first molar | MO |
| 30, lingual distal buccal occlusal mesial amalgam | 30, lower right first molar | MODBL |
| Number 8, mesial incisal composite | 8, upper right central incisor | MI |
| Number 24, facial composite | 24, lower left central incisor | F |
Take the fourth row. The operator lists five surfaces in a jumble on the lower right first molar. You tick all five, then write mesial first, occlusal next, distal because both proximal surfaces are involved, then buccal, then lingual: MODBL. It is still one restoration, charted once.
Mesial and distal on the chart diagram
The hardest part is usually not the letters but finding mesial on the diagram. Charts are drawn as if you face the patient, so the patient's right side is on your left. For teeth 1 to 8 and 25 to 32, the mesial surface is on the right of each tooth diagram; for teeth 9 to 24 it is on the left. If a filling lands on the wrong side, check which half of the arch the tooth is in before anything else.
Common mistakes
- Writing OD, OM or DOM. The proximal surface leads and distal goes last when both are present.
- Charting MOD as three separate fillings, which triples the restoration count on the chart.
- Putting the filling on the distal side of the diagram because of the chart's mirror image.
- Using O and B on an incisor or canine instead of I and F.
- Dropping a surface that was said once and quickly, usually the buccal or lingual at the end of the callout.
- Moving on before the material is charted. The code without amalgam or composite is half an entry.
For every letter and abbreviation in one place, see dental charting abbreviations and symbols.
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 and cavity classification chapters of the standard dental assisting texts, such as Modern Dental Assisting (Elsevier), which give the mesial first, distal last order for combined surfaces.
- Black's cavity classification. The original grouping of cavity preparations by surface, the basis of the MO, DO and MOD names for class II restorations.