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CDT Tooth Numbering & Oral Cavity Systems Guide
CDT Tooth Numbering Systems

Interactive Tooth Numbering Guide

Visual guide to ADA-recognized tooth numbering systems. Click on any tooth to see detailed information about numbering, type, and clinical significance.

Universal System: Permanent Dentition (1-32)

Permanent Teeth (1-32)
Primary Teeth (A-T)
UPPER ARCH (MAXILLARY)
1
3rd
Molar
2
2nd
Molar
3
1st
Molar
4
2nd
Bicuspid
5
1st
Bicuspid
6
Cuspid
7
Lateral
Incisor
8
Central
Incisor
9
Central
Incisor
10
Lateral
Incisor
11
Cuspid
12
1st
Bicuspid
13
2nd
Bicuspid
14
1st
Molar
15
2nd
Molar
16
3rd
Molar
LOWER ARCH (MANDIBULAR)
32
3rd
Molar
31
2nd
Molar
30
1st
Molar
29
2nd
Bicuspid
28
1st
Bicuspid
27
Cuspid
26
Lateral
Incisor
25
Central
Incisor
24
Central
Incisor
23
Lateral
Incisor
22
Cuspid
21
1st
Bicuspid
20
2nd
Bicuspid
19
1st
Molar
18
2nd
Molar
17
3rd
Molar

Click any tooth to see details

Interactive tooth diagram - hover and click teeth to explore the Universal/National numbering system

Numbering Sequence: Permanent teeth numbered 1-32. Starts at upper right third molar (#1), continues around upper arch to upper left third molar (#16), drops to lower left third molar (#17), and ends at lower right third molar (#32). Sequential clockwise pattern ensures consistent identification.

Primary Dentition (A-T)

UPPER PRIMARY TEETH
A
2nd
Molar
B
1st
Molar
C
Canine
D
Lateral
Incisor
E
Central
Incisor
F
Central
Incisor
G
Lateral
Incisor
H
Canine
I
1st
Molar
J
2nd
Molar
LOWER PRIMARY TEETH
T
2nd
Molar
S
1st
Molar
R
Canine
Q
Lateral
Incisor
P
Central
Incisor
O
Central
Incisor
N
Lateral
Incisor
M
Canine
L
1st
Molar
K
2nd
Molar

Click any primary tooth to see details

Primary (baby) teeth - 20 total teeth lettered A through T

Primary Lettering Sequence: Letters A-T identify 20 primary teeth. Tooth A = upper right 2nd molar through tooth T = lower right 2nd molar. Primary supernumeraries designated by adding "S" after adjacent tooth letter (e.g., "AS" is supernumerary adjacent to tooth "A").

Tooth Surface Terminology

Essential for accurate CDT coding. Each tooth surface has specific designation used in procedure documentation and claim submission.

Mesial (M)
Toward midline of mouth
Distal (D)
Away from midline
Occlusal (O)
Biting surface (posteriors)
Incisal (I)
Cutting edge (anteriors)
Facial/Labial (F/L)
Toward lips (anteriors)
Buccal (B)
Toward cheek (posteriors)
Lingual (L)
Toward tongue (all teeth)
Multi-Surface Coding Examples: "MOD" = Mesial-Occlusal-Distal restoration on posterior tooth. "MIF" = Mesial-Incisal-Facial restoration on anterior tooth. "DO" = Distal-Occlusal. Accurate surface designation mandatory for D2000-D2999 restorative codes to prevent claim denials.

ADA-Recognized Systems Comparison

Universal/National System

Code Set: JP
USA Primary Standard
Permanent: 1-32 sequential
Primary: A-T letters
Supernumeraries: 51-82 (permanent), [Letter]S (primary)

International ISO System

Code Set: JO
Global Standard (ANSI/ADA/ISO 3950)
Two-digit quadrant-based
Permanent: Quadrants 1-4, Teeth 1-8
Primary: Quadrants 5-8, Teeth 1-5

When to Use Universal (JP)

  • All USA dental insurance claims
  • Domestic treatment documentation
  • EHR/practice management systems
  • HIPAA-compliant electronic transactions
  • Standard communication within USA practices

When to Use ISO (JO)

  • International patient records
  • Cross-border treatment coordination
  • Dental laboratory prescriptions
  • Research and academic documentation
  • Countries outside United States

Clinical Application & Best Practices

Accuracy Requirements

  • Verify tooth number before every procedure
  • Double-check quadrant designation
  • Confirm primary vs. permanent status
  • Document surface codes precisely
  • Use radiographs for verification
  • Maintain consistent numbering system

Common Errors

  • Incorrect quadrant (mirror image errors)
  • Primary/permanent confusion
  • Missing surface designations
  • Supernumerary numbering mistakes
  • System mixing (JP vs JO)
  • Transposition errors in documentation
Revenue Protection: Tooth numbering errors cause 5-10% of claim denials, delaying payments 30-60 days per claim. Practices with 99%+ tooth numbering accuracy capture revenue 15-20% faster and reduce administrative burden by 40-50%. Investment in staff training and verification protocols yields immediate ROI through reduced denials and faster payment cycles.

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Proper tooth numbering and CDT coding are fundamental to revenue cycle success. Our expert team ensures 99%+ coding accuracy, eliminates claim denials, and accelerates payment cycles for optimal cash flow.

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