Knowledge of root and root canal morphology is a prerequisite for effective non-surgical and surgical endodontic treatments. The external and internal morphological features of roots are variable and complex, and several classifications have been proposed to define the various types of canal configurations that occur commonly. More recently, improvements in non-destructive digital image systems, such as cone-beam and micro-computed tomography, as well as the use of magnification in clinical practice, have increased the number of reports on complex root canal anatomy. Importantly, using these newer techniques, it has become apparent that it is not possible to classify many root canal configurations using the existing systems. The purpose of this article is to introduce a new classification system that can be adapted to categorize root and root canal configurations in an accurate, simple and reliable manner that can be used in research, clinical practice and training.

1. Dr Hany M. A. Ahmed
Department of Conservative
Dentistry, School of Dental
Sciences, Universiti Sains
Malaysia, Kelantan,
Malaysia
Dr Marco A. Versiani
Department of Restorative
Dentistry, Dental School of
Ribeirão Preto, University of
São Paulo, Brazil
Dr Gustavo De-Deus
Department of
Endodontics, School of
Dentistry, Federal
Fluminense University, Rio
de Janeiro, Brazil
Dr Paul M. H.
Dummer
School of Dentistry,
College of Biomedical
and Life Sciences, Cardiff
University, Cardiff, UK

2. Introduction
Ahmed HMA, Versiani MA, De-Deus G, Dummer PMH. A new system for classifying root and root canal morphology. International
“A thorough understanding of the complexity of the
root canal system is essential for understanding
the principles and problems of shaping and
cleaning, for determining the apical limits and
dimensions of canal preparations, and for
performing successful microsurgical procedures”

3. Introduction
Ahmed HMA, Versiani MA, De-Deus G, Dummer PMH. A new system for classifying root and root canal morphology. International
CARABELLI (1842) MUHLREITER (1870) BLACK (1890) GYSI (1892) PREISWERCK (1901) FISHER (1907)
DEWEY (1916)FASOLI (1913) HESS (1917) PUCCI & REIG (1944) DE DEUS (1960)
Data generated from classical studies demonstrated that the complexity of the
internal and external anatomy of teeth required the creation of a classification system.

4. Introduction
Ahmed HMA, Versiani MA, De-Deus G, Dummer PMH. A new system for classifying root and root canal morphology. International
Weine et al. (1969) were the first authors to categorize root canal configurations within a single root.
Oral Surg Oral Med Oral Pathol. 1969
Sep;28(3):419-25
Type I
(1-1)
Type II
(2-1)
Type III
(2-2)
Type IV
(1-2)
Later, Weine (1982) added an
additional type to his system.
Using Roman numbers, configurations were
classified into 3 types according to the pattern of
division of the main root canal along its course
from the pulp chamber to the root apex.

5. Introduction
Ahmed HMA, Versiani MA, De-Deus G, Dummer PMH. A new system for classifying root and root canal morphology. International
Oral Surg Oral Med Oral Pathol. 1974 Sep;38(3):456-64.
In 1974, Vertucci et al. identified more complex
canal systems in the study of 200 maxillary
second premolars using the clearing technique

6. Introduction
Ahmed HMA, Versiani MA, De-Deus G, Dummer PMH. A new system for classifying root and root canal morphology. International
Oral Surg Oral Med Oral Pathol. 1974 Sep;38(3):456-64.
Using Roman numbers, authors reported a
total of 8 configuration types according to
the pattern of division of the main root
canal along its course from the pulp
chamber to the root apex

7. Introduction
Ahmed HMA, Versiani MA, De-Deus G, Dummer PMH. A new system for classifying root and root canal morphology. International
Despite these efforts to systematically describe the diversity of canal
configurations, additional types of canal morphologies have been reported in
different populations.

8. Introduction
Ahmed HMA, Versiani MA, De-Deus G, Dummer PMH. A new system for classifying root and root canal morphology. International
Recently, based on previous reports and anatomical studies using micro-CT technology,
Versiani & Ordinola-Zapata (2015) were able to identify 37 types of root canal configuration.

9. Ahmed HMA, Versiani MA, De-Deus G, Dummer PMH. A new system for classifying root and root canal morphology. International
In summary, the most used
classification systems are
unable to categorize the
diversity of root canal
configurations as reported in
the literature.
Introduction

10. Aim
Ahmed HMA, Versiani MA, De-Deus G, Dummer PMH. A new system for classifying root and root canal morphology. International
Therefore, the purpose of this work is to
present a practical system that allows
students/trainees, clinicians and researchers
to classify root and root canal configurations
using any diagnostic method, regardless of
their accuracy and reliability.

11. Methodology
Ahmed HMA, Versiani MA, De-Deus G, Dummer PMH. A new system for classifying root and root canal morphology. International
• Root canal curvature (Schneider 1971, Pruett et al. 1997)
• Canal bifurcation and root fusion (Vertucci 2005)
• Accessory canals and apical ramifications (De Deus 1975)
• Dens invaginatus (Oehlers 1957)
• C-shaped canals (Melton et al. 1991, Fan et al. 2004, Kato et al. 2014)
• Taurodontism (Shaw 1928, Jafarzadeh et al. 2008)
• Supernumerary roots (Christie et al. 1991, Carlsen & Alexandersen 2000,
Song et al. 2010)
• And others
Exclusion Criteria
Literature already has many comprehensive classifications categorizing several morphological
aspects and developmental anomalies of the teeth. Therefore, this proposal system does not
include the following anatomical variations in the root and root canal system:
Despite such information could be useful, the benefits of any new system must be the
simplicity, so that it can be adopted universally!

12. Classification System
Ahmed HMA, Versiani MA, De-Deus G, Dummer PMH. A new system for classifying root and root canal morphology. International
This system includes codes for 3 components:
TN
Tooth Number
RNumber of Roots O-C-F Root Canal
Configuration
The canal configuration is
identified according to the
number of...
Orifice(s)
Canal System
Foramen (Foramina)
Tooth number can be written using any numbering system
(e.g. universal numbering system, Palmer Notation Numbering System or the FDI World Dental Federation System)

13. Classification System
Ahmed HMA, Versiani MA, De-Deus G, Dummer PMH. A new system for classifying root and root canal morphology. International
TN
Tooth Number
RNumber of Roots O-C-F Root Canal
Configuration
The canal configuration (O-
C-F) is represented by the
continuous course of the
Root Canal from the
Orifice...
Orifice(s)
Canal System
Foramen (Foramina)
...to the
Foramen
.
1
2
1
Canal Configuration = 1-2-1

14. Classification System
Ahmed HMA, Versiani MA, De-Deus G, Dummer PMH. A new system for classifying root and root canal morphology. International
Application in
Single-Rooted Teeth

15. Classification System : Application in Single-Rooted Teeth
Ahmed HMA, Versiani MA, De-Deus G, Dummer PMH. A new system for classifying root and root canal morphology. International
Code for Single-Rooted Teeth
TN1 O-C-F

16. Classification System: Application in Single-Rooted Teeth
Ahmed HMA, Versiani MA, De-Deus G, Dummer PMH. A new system for classifying root and root canal morphology. International
411 1-2-1
• Tooth Number: 41 (mandibular right
central incisor)
• 1 Root
• Canal configuration (O-C-F)
identified as 1-2-1

17. Classification System: Application in Single-Rooted Teeth
Ahmed HMA, Versiani MA, De-Deus G, Dummer PMH. A new system for classifying root and root canal morphology. International
441 1-2-3
• Tooth Number: 44 (mandibular right
first premolar)
• 1 Root
• Canal configuration (O-C-F)
identified as 1-2-3

18. Classification System: Application in Single-Rooted Teeth
Ahmed HMA, Versiani MA, De-Deus G, Dummer PMH. A new system for classifying root and root canal morphology. International
341 1-2
• Tooth Number: 34 (mandibular left
first premolar)
• 1 Root
• Canal configuration (O-C-F)
identified as 1-2

19. Classification System: Application in Single-Rooted Teeth
Ahmed HMA, Versiani MA, De-Deus G, Dummer PMH. A new system for classifying root and root canal morphology. International
211 1
* If the numbers of
Orifice (O), Canal
(C) and Foramen
(F) are the same,
then a single code
is used.
• Tooth Number: 21 (maxillary left
central incisor)
• 1 Root
• Canal configuration (O-C-F)
identified as 1-1-1

20. Classification System: Application in Single-Rooted Teeth
Ahmed HMA, Versiani MA, De-Deus G, Dummer PMH. A new system for classifying root and root canal morphology. International
151 2
• Tooth Number: 15 (maxillary right
second premolar)
• 1 Root
• Canal configuration (O-C-F)
identified as 2-2-2
* If the numbers of
Orifice (O), Canal
(C) and Foramen
(F) are the same,
then a single code
is used.

21. Classification System: Application in Single-Rooted Teeth - Summary
Ahmed HMA, Versiani MA, De-Deus G, Dummer PMH. A new system for classifying root and root canal morphology. International
1111 1152 1341-2 1411-2-1 1441-2-3

22. Classification System
Ahmed HMA, Versiani MA, De-Deus G, Dummer PMH. A new system for classifying root and root canal morphology. International
Application in
Double-Rooted Teeth

23. Classification System
Ahmed HMA, Versiani MA, De-Deus G, Dummer PMH. A new system for classifying root and root canal morphology. International
The code for double-rooted teeth includes
the identification of both roots
TN R1 R22 O-C-F O-C-F
Code for Double-Rooted Teeth
* If the numbers of
Orifice (O), Canal
(C) and Foramen
(F) are the same,
then a single code is
used

24. Classification System: Application in Double-Rooted Teeth
Ahmed HMA, Versiani MA, De-Deus G, Dummer PMH. A new system for classifying root and root canal morphology. International
14 B P
2
Buccal Root
• Tooth Number: 14 (maxillary right first
premolar)
• 2 Roots: B (Buccal) and P (Palatal)
• Canal configuration in both roots: 1-1-1
Palatal Root
1 1
Acessory Canal

25. Classification System: Application in Double-Rooted Teeth
Ahmed HMA, Versiani MA, De-Deus G, Dummer PMH. A new system for classifying root and root canal morphology. International
24 B P
2
Buccal Root
Palatal Root
1-2-1-2 1
• Tooth Number: 24 (maxillary left first
premolar)
• 2 Roots: B (Buccal) and P (Palatal)
• Canal configuration in the B root: 1-2-1-2
• Canal configuration in the P root: 1-1-1

26. Classification System: Application in Double-Rooted Teeth
Ahmed HMA, Versiani MA, De-Deus G, Dummer PMH. A new system for classifying root and root canal morphology. International
33 B L
2
Buccal Root
Lingual Root
1 11
If the root canals
have a common
configuration
coronal to canal
bifurcation...
…then, canal
configuration common
to both roots is written
before the
identification of the
roots
• Tooth Number: 33 (mandibular left canine)
• 2 Roots: B (Buccal) and L (Lingual)
• Canal configuration in both roots: 1-1-1

27. Classification System: Application in Double-Rooted Teeth
Ahmed HMA, Versiani MA, De-Deus G, Dummer PMH. A new system for classifying root and root canal morphology. International
21 M D
2
Mesial Root
Distal Root
1 11
Common
configuration
Acessory Canals
• Tooth Number: 21 (maxillary left central
incisor)
• 2 Roots: M (Mesial) and D (Distal)
• Canal configuration in both roots: 1-1-1

28. Classification System: Application in Double-Rooted Teeth
Ahmed HMA, Versiani MA, De-Deus G, Dummer PMH. A new system for classifying root and root canal morphology. International
44 B L
2
Buccal Root
Lingual Root
1-2 11
Acessory Canal
Common
configuration
• Tooth Number: 44 (mandibular right first
premolar)
• 2 Roots: M (Mesial) and L (Lingual)
• Canal configuration in the B root: 1-2
• Canal configuration in the L root: 1-1

29. Classification System: Application in Double-Rooted Teeth - Summary
Ahmed HMA, Versiani MA, De-Deus G, Dummer PMH. A new system for classifying root and root canal morphology. International
214B1P1 224B1-2-1-2P1 2211M1D1 2331B1L1 2441B1-2L1

30. Classification System
Ahmed HMA, Versiani MA, De-Deus G, Dummer PMH. A new system for classifying root and root canal morphology. International
Application in
Multiple-Rooted Teeth

31. Classification System
Ahmed HMA, Versiani MA, De-Deus G, Dummer PMH. A new system for classifying root and root canal morphology. International
The code for multiple-rooted teeth
includes the identification of more than 2
roots
TN R1 R2 Rn
n O-C-F O-C-F
Code for Multiple-Rooted Teeth
O-C-F
* If the numbers of
Orifice (O), Canal
(C) and Foramen
(F) are the same,
then a single code is
used

32. Classification System: Application in Multiple-Rooted Teeth
Ahmed HMA, Versiani MA, De-Deus G, Dummer PMH. A new system for classifying root and root canal morphology. International
16 MB DB P
3 1 1 1
MB Root DB Root
P Root
• Tooth Number: 16 (maxillary right first molar)
• 3 Roots: MB (mesiobuccal), DB (distobuccal)
and P (Palatal)
• Canal configuration in all roots: 1-1-1

33. Classification System: Application in Multiple-Rooted Teeth
Ahmed HMA, Versiani MA, De-Deus G, Dummer PMH. A new system for classifying root and root canal morphology. International
26 MB DB P
3 2-1 1 1
MB Root
DB Root
P Root
• Tooth Number: 26 (maxillary left first molar)
• 3 Roots: MB (mesiobuccal), DB (distobuccal)
and P (Palatal)
• Canal configuration in the MB root: 2-1
• Canal configuration in the DB and P roots: 1-
1-1

34. Classification System: Application in Multiple-Rooted Teeth
Ahmed HMA, Versiani MA, De-Deus G, Dummer PMH. A new system for classifying root and root canal morphology. International
27 MB DB MP DP
4 2-1 1 1
MB Root
DB Root
DP Root
1
MP Root
• Tooth Number: 27 (maxillary left second
molar)
• 4 Roots: MB (mesiobuccal), DB (distobuccal)
MP (mesiopalatal) and DP (distopalatal)
• Canal configuration in the MB root: 2-1
• Canal configuration in the DB, MP, and DP
roots: 1-1-1

35. Classification System: Application in Multiple-Rooted Teeth
Ahmed HMA, Versiani MA, De-Deus G, Dummer PMH. A new system for classifying root and root canal morphology. International
47 M DB DL
3 2 1 1
DB Root
DL Root
M Root
• Tooth Number: 47 (mandibular right second
molar)
• 3 Roots: M (mesial), DB (distobuccal) and DL
(distolingual)
• Canal configuration in the M root: 2-2-2
• Canal configuration in the DB and DL roots: 1-
1-1

36. Classification System: Application in Multiple-Rooted Teeth - Summary
Ahmed HMA, Versiani MA, De-Deus G, Dummer PMH. A new system for classifying root and root canal morphology. International
316 MB1 DB1 P1 326 MB2-1 DB1 P1 427 MB2-1 DB1 MP1 DP1 347 M2 DB1 DL1

37. Classification System
Ahmed HMA, Versiani MA, De-Deus G, Dummer PMH. A new system for classifying root and root canal morphology. International
Application in
Different Teeth

38. Classification System: Application
Ahmed HMA, Versiani MA, De-Deus G, Dummer PMH. A new system for classifying root and root canal morphology. International
1121 1311-2-1-2 1411-2-3-1 1421-2-1-2-1 1321-2-1
Single-rooted teeth Double-rooted teeth Multiple-rooted teeth

39. Classification System: Application
Ahmed HMA, Versiani MA, De-Deus G, Dummer PMH. A new system for classifying root and root canal morphology. International
324 MB1 DB1 P1 1431-2 1341-2 1441-2-1 1252-1-2
Single-rooted teeth Double-rooted teeth Multiple-rooted teeth

40. Classification System: Application
Ahmed HMA, Versiani MA, De-Deus G, Dummer PMH. A new system for classifying root and root canal morphology. International
327 MB1 DB1 P1 316 MB3-1-2-1 DB1 P1 326 MB2-1-3 DB1 P1 337 M2-1-2 DB1 DL1
Single-rooted teeth Double-rooted teeth Multiple-rooted teeth

41. Conclusion
Ahmed HMA, Versiani MA, De-Deus G, Dummer PMH. A new system for classifying root and root canal morphology. International
The new proposed classification attempts to provide a simple,
accurate and practical system that allows students, dental
practitioners and researchers to classify root and root canal
configurations. It provides detailed information on the tooth
number, number of roots and root canal configuration types,
whilst excluding developmental anomalies and minor canal
anatomy to pave the way for simplicity and universal adoption.