Aplicacion de un nuevo sistema de clasificacion de conductos radiculares

doi:10.1111/iej.13199
REVIEW
Application of a new system for classifying tooth,
root and canal morphology in the primary
dentition
H. M. A. Ahmed1
, P. K. Musale2
, O. I. El Shahawy3 & P. M. H. Dummer4
1
Department of Restorative Dentistry, Faculty of Dentistry, University of Malaya, Kuala Lumpur, Malaysia; 2“Little Ones Big
Smiles” Laser and Microscope Integrated Paediatric Dentistry, Pune, India; 3Department of Paediatric Dentistry, Faculty of
Dentistry, Cairo University, Cairo, Egypt; and 4School of Dentistry, College of Biomedical and Life Sciences, Cardiff University,
Cardiff, UK
Abstract
Ahmed HMA, Musale PK, El Shahawy OI, Dummer
PMH. Application of a new system for classifying tooth, root
and canal morphology in the primary dentition. International
Endodontic Journal, 53, 27–35, 2020.
Knowledge of root and canal morphology is essential
for the effective practice of root canal treatment. Paediatric endodontics aims to preserve fully functional
primary teeth in the dental arch; however, pulpectomy procedures in bizarre and tortuous canals
encased in roots programmed for physiologic resorption are unique challenges. A new coding system for
Introduction
The morphology of roots and canal systems is variable
and complex. During root canal treatment, a lack of
knowledge on root and canal morphology is often associated with a failure to locate, instrument, irrigate and
fill canals adequately (Vertucci 2005, Cantatore et al.
2006). Therefore, an understanding of root and canal
morphology of the human dentition is essential for effective root canal treatment procedures (Vertucci 2005).
Pulpectomy procedures in primary teeth aim to
ensure normal physiologic exfoliation and eruption of
Correspondence: Hany Mohamed Aly Ahmed, Department of
Restorative Dentistry, Faculty of Dentistry, University of
Malaya, 50603, Kuala Lumpur, Malaysia (e-mail: [email protected]).
© 2019 International Endodontic Journal. Published by John Wiley & Sons Ltd
classifying the roots and main canals (https://doi.org/
10.1111/iej.12685), accessory canals (https://doi.
org/10.1111/iej.12800) and developmental anomalies (https://doi.org/10.1111/iej.12867) has been
introduced recently. This paper discusses challenges
for describing root and canal morphology in primary
teeth and describes the potential application of the
new classification system for root canals in the primary dentition.
Keywords: canal morphology, deciduous teeth,
new classification, primary teeth.
Received 29 May 2019; accepted 5 August 2019
the successor tooth or their long-term survival when
their retention is required. Root and canal morphology
in the primary dentition has a wide range of anatomical variations and is unpredictable (Ahmed 2013,
Ozcan et al. 2016a, Reddy et al. 2018, Neboda et al.
2018, El Hachem et al. 2019). As a consequence, the
bizarre and tortuous canals encased in roots programmed for physiologic resorption are a unique challenge for dentists (Dummett & Kopel 2002,
Waterhouse et al. 2011, Ahmed 2013, 2014).
With an increasing range of anatomical complexities being reported and the deficiencies of the existing
systems for categorizing canal systems becoming more
apparent, a new system for classifying root and canal
morphology has been proposed, which provides
detailed information on tooth notation, number of
roots and root canal configuration in addition to
accessory canals and tooth anomalies (Ahmed et al.
International Endodontic Journal, 53, 27–35, 2020
27
Classification of canal anatomy in primary teeth Ahmed et al.
2017, 2018, Ahmed & Dummer 2018a,b). The present article discusses the various challenges when
describing root and canal morphology in primary
teeth and the application of the new system to classify
root and canal morphology in the primary dentition.
Review
Challenges for describing root canal morphology in
the primary dentition
Anatomical variations
Root canal configurations. There are wide range of
anatomical variations in the primary dentition, especially molars. Root canal configurations change
dynamically with increasing age, especially in
mandibular molars, because of the deposition of dentine islands that influence the number, size and shape
of canals within primary roots (Camp 2008). In addition, physiologic root resorption changes the morphology of the root apex leading to difficulty in working
length determination (Camp 2008).
Incisors and canines—Primary anteriors are usually
single-rooted with a single root canal (Cleghorn et al.
2010, Waterhouse et al. 2011). However, several
reports have documented the occurrence of accessory
roots and root canals in primary anterior teeth (Barker et al. 1975, Cleghorn et al. 2010, Musale & Hegde
2010, Ahmed 2013, Ahmed & Hashem 2016), especially double-rooted primary maxillary canines
(Mochizuki et al. 2001). Musale & Hegde (2010) documented the successful endodontic management of a
unilateral three-rooted primary maxillary canine.
Figure 1 Different tooth numbering systems using the new
classification system for root and canal morphology (Upper –
FDI, Middle – Palmer, Lower – Universal).
28
International Endodontic Journal, 53, 27–35, 2020
Maxillary molars—Primary maxillary molars may
have two to four roots, with the three-rooted variant
being the most common (Cleghorn et al. 2010,
Ahmed 2013). The double-rooted variant, in which
the distobuccal root is fused with the palatal root, is
also common (Cleghorn et al. 2010, Ahmed 2013).
The prevalence of a second mesiobuccal root canal
can be as high as 95% (Sarkar & Rao 2002, Waterhouse et al. 2011). Three mesiobuccal canals have
been documented (Ahmed et al. 2016), and other
complex root canal configurations have been reported
in the distobuccal and palatal roots (Cleghorn et al.
2010, Ahmed 2013).
Mandibular molars—Primary mandibular molars can
have one to four roots; the double-rooted variant is
the most common (Cleghorn et al. 2010, Ahmed
2013, Yang et al. 2013, Fumes et al. 2014). Accessory roots in primary mandibular molars, especially
in second molars, have been reported in a number of
population groups (Song et al. 2009, Liu et al. 2010,
Tu et al. 2010, Yang et al. 2013). The mesial roots of
primary mandibular molars usually have two root
canals (Bagherian et al. 2010) but three canals have
also been reported (Sarkar & Rao 2002). The distal
root in mandibular primary molars usually has one
or two canals (Ahmed 2013), but three separate
canals in the distal root have been reported in
extracted mandibular primary second molars when
evaluated using CBCT (Demiriz et al. 2018).
Accessory canals. Accessory canals are common in the
primary dentition, especially in the furcation area
(Wrbas et al. 1997, Dammaschke et al. 2004,
Figure 2 Degree/stage of root resorption is not considered in
the new system. Notably, palatal root resorption (the hidden
third bucco-palatal dimension) usually is at a more advanced
stage compared to apical since the eruption of the permanent successors of primary incisors is from a palatal direction.
© 2019 International Endodontic Journal. Published by John Wiley & Sons Ltd
Ahmed et al. Classification of canal anatomy in primary teeth
Figure 3 Drawings showing that physiologic root resorption
may change the root canal configuration of a given root,
which could be evident during the physiologic root resorption of a root canal filled primary molar.
Figure 6 Drawings showing different canal configurations in
maxillary primary molars.
(a)
(b)
(c)
(d)
Figure 4 Drawings showing different canal configurations in
mandibular primary incisors.
Figure 7 Clinical cases of primary anterior teeth using the new
classification system. (a,b), Maxillary anteriors (Courtesy Dr.
Mohamed Salah Shalaby), (c) Mandibular primary incisor
(Courtesy Dr. Abhishek Soni), (d) Three-rooted maxillary canine
(Reproduced with permission from Quintessence - Musale &
Hegde 2010).
Berscheid 2015, Sharma et al. 2016). One micro-CT
study reported that approx. 83% of extracted primary
molars had a least one accessory canal in the furcation area (chamber/furcation canals) (Berscheid
2015), whilst another reported that all mesial and
distal roots of primary second mandibular molars had
lateral canals (El Hachem et al. 2019). It is worth
noting that only a small number of those canals are
patent, and the majority usually terminate within the
root dentine (Berscheid 2015, Sharma et al. 2016).
Figure 5 Drawings showing different canal configurations in
mandibular primary molars.
© 2019 International Endodontic Journal. Published by John Wiley & Sons Ltd
Tooth anomalies. The occurrence of root and canal
anomalies in the primary dentition has been
International Endodontic Journal, 53, 27–35, 2020
29
Classification of canal anatomy in primary teeth Ahmed et al.
(a)
continuous formation of secondary dentine, modifies
the root canal system over time (Rimondini & Baroni
1995, Waterhouse et al. 2011). In addition, pulp
and/or periodontal inflammation may cause pathological changes in the resorption process and further
complicate root and canal morphology (Rimondini &
Baroni 1995). As a consequence, root and canal
anatomy in resorbed roots is unpredictable since the
resorptive process along the root surface is uneven
and is subject to continuous morphological changes
(Rimondini & Baroni 1995, Waterhouse et al. 2011).
Moreover, the roots are also subject to internal
resorption that can further modify the root canals
(Rimondini & Baroni 1995, Waterhouse et al. 2011,
Ahmed 2014).
(b)
(c)
(d)
Application of the new root and canal
classification system in the primary dentition
Figure 8 Clinical cases of primary mandibular molar teeth
using the new classification system.
documented with Radix Entomolaris, taurodontism,
root fusion, dens evaginatus, dens invaginatus,
enamel pearls being reported (Kupietzky & Rozenfarb
1993, Eden et al. 2002, Levitan & Himel 2006, Jafarzadeh et al. 2008, Song et al. 2009, Cleghorn et al.
2010, King et al. 2010, Venugopal et al. 2010, Nagaveni & Umashankara 2012, Ahmed 2013) and Cshaped canals in mandibular molars (Ballal et al.
2006, Ozcan et al. 2016b). Fusion between primary
molars and supernumerary primary teeth has also
been documented (Caceda et al. 1994, Wang et al.
2013, Mukhopadhyay & Mitra 2014).
Physiologic root resorption
Physiologic root resorption, which starts soon after
the complete formation of the root and the
(a)
(b)
Root and canal morphology
The classification system of Ahmed et al. (2017)
includes codes for three separate components: the
tooth number, the number of roots and the root canal
configuration within each root. The tooth number
(TN) can be written using any numbering system (e.g.
universal numbering system, Palmer Notation Numbering System or the FDI World Dental Federation System; Fig. 1) or with a suitable abbreviation if the tooth
number cannot be identified (e.g. extracted teeth). The
number of roots is added as a superscript before the
tooth number (TN), and the root canal configuration is
added as a superscript on the right after the tooth
number (Ahmed et al. 2017) (Fig. 1). For simplicity,
the presence/extent of physiologic root resorption is
not considered in the new system (Fig. 2). However, if
the root canal configuration has been altered as a consequence of physiologic root resorption of a root canal
filled tooth, then the code for root canal configuration
has to be changed accordingly (Fig. 3).
(c)
Figure 9 Clinical cases of primary maxillary molar teeth using the new classification system.
30
International Endodontic Journal, 53, 27–35, 2020
© 2019 International Endodontic Journal. Published by John Wiley & Sons Ltd
Ahmed et al. Classification of canal anatomy in primary teeth
(a)
(c)
(b)
(d)
(e)
Figure 10 CBCT images showing the anatomy of the tooth, root and canals and its description using the new system. (a)
Sagittal section, (b) Coronal section, (c) Axial section (coronal), (d) Axial section (middle), (e) Axial section (apical).
A
B
C
D
Figure 12 Details of the code describing the root and canal
morphology in a primary molar. A: Tooth number and number of roots. B: Accessory (furcation) canal(s). C: Description
of the mesial root and canal configuration. D: Details of the
distal root and canal configuration.
Figure 11 Drawings showing the application of the new system for classifying accessory canals in the primary dentition
(A: Apical third, C: Coronal third, D: Delta).
© 2019 International Endodontic Journal. Published by John Wiley & Sons Ltd
It is clear that root and canal morphology in the
primary dentition is variable and complex. The new
classification system is more accurate and simpler
compared with the Vertucci system (and its supplementary configurations) that was developed to categorize canal systems in permanent teeth. The
Vertucci system uses Roman numerals for each ‘type’
International Endodontic Journal, 53, 27–35, 2020
31
Classification of canal anatomy in primary teeth Ahmed et al.
chamber that merge apically – coded as 1722-1. Figure 5a shows a double-rooted mandibular right primary molar coded as 284 M2 D1; the mesial (M) and
distal (D) roots have 2 and 1 canal(s), respectively.
Figure 6a shows a three-rooted maxillary left primary
second molar coded as 365 MB1 DB1 P1 having three
roots in which each of the mesiobuccal (MB), distobuccal (DB) and palatal (P) roots have one canal.
Other examples are shown in Figs 4–6 in addition to
clinical cases in Figs 7–10.
Figure 13 Despite potential confusion between accessory
canals and resorption defects, the close approximation of the
permanent successor and loss of integrity of the root outline
indicate the presence of resorption defects.
Figure 14 A three-rooted mandibular tooth 74 (M, D, DL) –
Radix Entomolaris type 2 (type II: curvature in the coronal
third and straight continuation to the apex).
of root canal configuration (Vertucci et al. 1974,
Gulabivala et al. 2001, 2002, Ng et al. 2001, Sert &
Bayirli 2004). However, it does not take into consideration the number of roots in several tooth types
(such as anterior teeth). In addition, it was not
intended for the primary dentition (Vertucci 1984).
The description of tooth anatomy in the primary
dentition using the Ahmed et al. (2017) system follows the same format as for permanent teeth. Figure 1 shows a single-rooted maxillary right primary
central incisor coded as 1511 with a single canal. Figure 4a shows a single-rooted mandibular left primary
lateral incisor with two canals leaving the pulp
32
International Endodontic Journal, 53, 27–35, 2020
Accessory canals
Accessory canals in primary molars can be classified
using an existing system (Ahmed et al. 2018). The
length of the root is divided into thirds: the coronal
third (C), which starts from an imaginary line from
the most apical portion of the pulp chamber, middle
third (M) and apical third (A) ending at the canal terminus (Fig. 11). Each third is identified as a superscript within parenthesis after the tooth number. For
accessory canals leaving the floor of the pulp chamber, the superscript is written before the root notation. The configuration of these accessory canals can
be described as for the main root canal configuration.
An apical delta is identified by the letter ‘D’ (Fig. 11).
In some instances, the accessory/chamber canal may
not end in a foramen or be looped (Fig. 11). 1511(A1)
describes a single-rooted maxillary right primary central incisor having a single root canal, and a single
accessory canal located in the apical third of the root
(Fig. 11a). 1511(D) describes a single-rooted maxillary
right primary central incisor having a single root
canal and an apical delta (Fig. 11c). 274 M1(A1) D1
describes a double-rooted tooth 74 in which the
mesial root has a single root canal and single accessory canal in the apical third of the root; the distal
root has one single canal (Fig. 11d). 274 (1)M1 D1
describes a double-rooted tooth 74 with the same
canal morphology but with a single furcation canal
(Fig. 11e). 274 (1-0)M1 D1 describes the same tooth
with a furcation canal configuration 1-0 (nonpatent)
(Fig. 11f). Figure 12 shows a detailed description of a
mandibular molar with two furcation canals.
The description of accessory canals using the new
system in the permanent dentition is clear and can be
applied in clinical and experimental settings. However, in the primary dentition, especially when clinically the permanent successor is close to the roots of
primary teeth, the differentiation of accessory canals
(small canals leaving the root canal that (usually)
communicate with the external surface of the root or
© 2019 International Endodontic Journal. Published by John Wiley & Sons Ltd
Ahmed et al. Classification of canal anatomy in primary teeth
(a)
(b)
(c)
(e)
(f)
(g)
(h)
(d)
(i)
Figure 15 Application of the new system to classify primary teeth with fused roots – a sample using micro-CT imaging – Root
fusion types 3 – DB fused to P (Reproduced with permission from Wiley - Ahmed et al. 2016).
furcation) from early physiologic resorption defects is
challenging given that both may overlap and appear
with similar patterns on 2D radiographic images after
root canal filling with a resorbable paste (Fig. 13).
Therefore, the classification of accessory canals in a
clinical setting is advisable only when the primary
tooth is not about to exfoliate or if there are no signs
of extensive root resorption. The application of the
system in experimental settings will be more accurate
since the investigator can differentiate accessory
canals from resorption areas if present.
Tooth anomalies
Similar to the permanent dentition, the abbreviation
of an anomaly (A) is added between brackets before
the tooth number (TN) that is (A)TN (Ahmed & Dummer 2018a,b). For instance, (DE)1 511 describes a
dens evaginatus (DE) in a single-rooted maxillary
right primary central incisor tooth with a single
© 2019 International Endodontic Journal. Published by John Wiley & Sons Ltd
canal. (DIIII)1511 describes a single-rooted tooth 51
with a Dens Invaginatus type III and single canal.
(RE1)374 M1 D1 DL1 describes a three-rooted tooth
74 [mesial (M), distal (D) and distolingual (DL) –
Radix Entomolaris type 1 (RE)]; each root has a single
root canal (Fig. 14).1 ST1/1511 describes a singlerooted tooth 51 fused to a single-rooted Supernumerary Tooth (ST) – both with single canals.
If the anomaly is related to one or more roots in
double- or multirooted teeth, respectively, then the
anomaly should be written after the abbreviation of
the affected root. Thus, 275 M1 D1(EP) describes a
double-rooted tooth 75 having an enamel pearl (EP)
related to the D root – both mesial and distal roots
having a single canal. Root fusion (RF) in threerooted teeth is an exception in which all types should
be written before the tooth number (TN).
(RF3)365 MB3 DB2-1-2 P2-1 describes a three-rooted
tooth 65 having fused DB (canal configuration 2-1-2)
International Endodontic Journal, 53, 27–35, 2020
33
Classification of canal anatomy in primary teeth Ahmed et al.
[Root fusion (RF) type 3 (Ahmed & Dummer 2018a,
b)] and P (canal configuration 2-1) roots whilst the
MB (canal configuration 3) is not fused (Ahmed &
Dummer 2018a,b) (Fig. 15).
Conclusions
•
•
•
The morphology of root canals, accessory canals
and tooth anomalies in the primary dentition can
be classified using the system of Ahmed et al.
(2017), 2018 and Ahmed & Dummer 2018b, in a
similar way to the permanent dentition.
For simplicity, the stage of physiologic root resorption is not considered when classifying primary
teeth using the new system.
Physiologic root resorption and the presence of a
permanent successor close to the roots of primary
teeth are challenges for accurate interpretation of
accessory canals and several anomalies especially
in clinical settings.
Conflict of Interest
The authors have stated explicitly that there are no
conflicts of interest in connection with this article.
References
Ahmed HMA (2013) Anatomical challenges, electronic
working length determination and current developments
in root canal preparation of primary molar teeth. International Endodontic Journal 46, 1011–22.
Ahmed HMA (2014) Pulpectomy procedures in primary
molar teeth. European Journal of General Dentistry 3, 3–10.
Ahmed HMA, Dummer PMH (2018a) Advantages and applications of a new system for classifying roots and canal systems in research and clinical practice. European Endodontic
Journal 3, 9–17.
Ahmed HMA, Dummer PMH (2018b) A new system for classifying tooth, root and canal anomalies. International
Endodontic Journal 51, 389–404.
Ahmed HMA, Hashem AA (2016) Accessory roots and root
canals in human anterior teeth: a review and clinical considerations. International Endodontic Journal 49, 724–36.
Ahmed HMA, Khamis MF, Gutmann JL (2016) Seven root
canals in a deciduous maxillary molar detected by the
dental operating microscope and micro-computed tomography. Scanning 38, 554–7.
Ahmed HMA, Versiani MA, De-Deus G, Dummer PMH
(2017) A new system for classifying root and root canal
morphology. International Endodontic Journal 50, 761–70.
34
International Endodontic Journal, 53, 27–35, 2020
Ahmed HMA, Neelakantan P, Dummer PMH (2018) A new
system for classifying accessory canal morphology. International Endodontic Journal 51, 164–76.
Bagherian A, Kalhori KA, Sadeghi M, Mirhosseini F, Parisay
I (2010) An in vitro study of root and canal morphology
of human deciduous molars in an Iranian population.
Journal of Oral Science 52, 397–403.
Ballal S, Gupta T, Kandaswamy D (2006) Management of a
retained primary maxillary second molar with C-Shaped
canal confirmed with the help of spiral computed tomography. Endodontology 18, 14–9.
Barker BC, Parsons KC, Williams GL, Mills PR (1975) Anatomy of root canals. IV deciduous teeth. Australian Dental
Journal 20, 101–6.
Berscheid M (2015) Presence of accessory canals in the furcation region of primary molars. Master of Dentistry Thesis. University of Manitoba, Canada.
Caceda JH, Creath CJ, Thomas JP, Thornton JB (1994) Unilateral fusion of primary molars with the presence of a
succedaneous supernumerary tooth: case report. Pediatric
Dentistry 16, 53–5.
Camp JH (2008) Diagnosis dilemmas in vital pulp therapy:
treatment for the toothache is changing, especially in
young, immature teeth. Pediatric Dentistry 30, 197–205.
Cantatore G, Berutti E, Castellucci A (2006) Missed anatomy: frequency and clinical impact. Endodontic Topics 15,
3–31.
Cleghorn BM, Boorberg NB, Christie WH (2010) Primary
human teeth and their root canal systems. Endodontic
Topics 23, 6–33.
Dammaschke T, Witt M, Ott K, Sch€
afer E (2004) Scanning
electron microscopic investigation of incidence, location,
and size of accessory foramina in primary and permanent
molars. Quintessence International 35, 699–705.
Demiriz L, Bodrumlu EH, Icen M (2018) Evaluation of root
canal morphology of human primary mandibular second
molars by using cone beam computed tomography. Nigerian Journal of Clinical Practice 21, 462–7.
Dummett CO Jr, Kopel HM (2002) Pediatric endodontics. In:
Ingle JI, Bakland LK, eds. Endodontics, 5th edn. Hamilton:
BC Decker Inc, pp 861–902.
Eden EK, Koca H, Sen BH (2002) Dens invaginatus in a primary molar: report of case. ASDC Journal of Dentistry for
Children 69, 49–53, 12.
El Hachem C, Kaloustian MK, Nehme W et al. (2019)
Three-dimensional modeling and measurements of root
canal anatomy in second primary mandibular molars: a
case series micro CT study. European Archives of Paediatric
Dentistry.
https://doi.org/10.1007/s40368-01900426-8.
Fumes AC, Sousa-Neto MD, Leoni GB et al. (2014) Root
canal morphology of primary molars: a micro-computed
tomography study. European Archives Paediatric Dentistry
15, 317–26.
© 2019 International Endodontic Journal. Published by John Wiley & Sons Ltd
Ahmed et al. Classification of canal anatomy in primary teeth
Gulabivala K, Aung TH, Alavi A, Ng YL (2001) Root and
canal morphology of Burmese mandibular molars. International Endodontic Journal 34, 359–70.
Gulabivala K, Opasanon A, Ng YL, Alavi A (2002) Root and
canal morphology of Thai mandibular molars. International
Endodontic Journal 35, 56–62.
Jafarzadeh H, Azarpazhooh A, Mayhall JT (2008) Taurodontism: a review of the condition and endodontic treatment
challenges. International Endodontic Journal 41, 375–88.
King NM, Tongkoom S, Wong HM (2010) Morphological
and numerical characteristics of the Southern Chinese
dentitions. Part III: anomalies in the primary dentition.
The Open Anthropology Journal 3, 25–36.
Kupietzky A, Rozenfarb N (1993) Enamel pearls in the primary dentition: report of two cases. ASDC Journal of Dentistry for Children 60, 63–6.
Levitan ME, Himel VT (2006) Dens evaginatus: literature
review, pathophysiology, and comprehensive treatment
regimen. Journal of Endodontics 32, 1–9.
Liu JF, Dai PW, Chen SY et al. (2010) Prevalence of 3-rooted
primary mandibular second molars among Chinese
patients. Pediatric Dentistry 32, 123–6.
Mochizuki K, Ohtawa Y, Kubo S, Machida Y, Yakushiji M
(2001) Bifurcation, birooted primary canines: a case report.
International Journal of Paediatric Dentistry 11, 380–5.
Mukhopadhyay S, Mitra S (2014) Anomalies in primary
dentition: their distribution and correlation with permanent dentition. Journal of Natural Science, Biology, and Medicine 5, 139–43.
Musale PK, Hegde VS (2010) Endodontic treatment of a
three-rooted primary maxillary right canine. ENDO –
Endodontic Practice Today 4, 309–13.
Nagaveni NB, Umashankara KV (2012) Radix entomolaris
and paramolaris in children: a review of the literature.
Journal of Indian Society of Pedodontics and Preventive Dentistry 30, 94–102.
Neboda C, Anthonappa RP, King NM (2018) Preliminary
investigation of the variations in root canal morphology of
hypomineralised second primary molars. International Journal of Paediatric Dentistry 28, 310–8.
Ng YL, Aung TH, Alavi A, Gulabivala K (2001) Root and
canal morphology of Burmese maxillary molars. International Endodontic Journal 34, 620–30.
Ozcan G, Sekerci AE, Cantekin K, Aydinbelge M, Dogan S
(2016a) Evaluation of root canal morphology of human
primary molars by using CBCT and comprehensive review
of the literature. Acta Odontologica Scandinavica 74, 250–8.
Ozcan G, Sekerci AE, Kocoglu F (2016b) C-shaped mandibular primary first molar diagnosed with cone beam computed tomography: a novel case report and literature
review of primary molars’ root canal systems. Journal of
Indian Society of Pedodontics and Preventive Dentistry 34,
397–404.
Reddy NV, Daneswari V, Patil R, Meghana B, Reddy A,
Niharika P (2018) Three-dimensional assessment of root
© 2019 International Endodontic Journal. Published by John Wiley & Sons Ltd
canal morphology of human deciduous molars using cone
beam computed tomography: An In vitro Study. International Journal of Pedodontic Rehabilitation 3, 36–41.
Rimondini L, Baroni C (1995) Morphologic criteria for root
canal treatment of primary molars undergoing resorption.
Endodontics & Dental Traumatology 11, 136–41.
Sarkar S, Rao AP (2002) Number of root canals, their shape,
configuration, accessory root canals in radicular pulp morphology. A preliminary study. Journal of Indian Society of
Pedodontics and Preventive Dentistry 20, 93–7.
Sert S, Bayirli GS (2004) Evaluation of the root canal configurations of the mandibular and maxillary permanent teeth
by gender in the Turkish population. Journal of Endodontics
30, 391–8.
Sharma U, Gulati A, Gill N (2016) An investigation of accessory canals in primary molars – an analytical study. International Journal of Paediatric Dentistry 26, 149–56.
Song JS, Kim SO, Choi BJ, Choi HJ, Son HK, Lee JH (2009)
Incidence and relationship of an additional root in the
mandibular first permanent molar and primary molars.
Oral Surgery Oral Medicine Oral Pathology Oral Radiology
and Endodontology 107, e56–60.
Tu MG, Liu JF, Dai PW, Chen SY, Hsu JT, Huang HL (2010)
Prevalence of three-rooted primary mandibular first molars
in Taiwan. Journal of the Formosan Medical Association
109, 69–74.
Venugopal RN, Arun PRV, Krishna KR, Mohan G, Sarasakavitha D (2010) Endodontic treatment in primary molars
with taurodontism. Annuals and Essences of Dentistry 2,
52–5.
Vertucci FJ (1984) Root canal anatomy of the human permanent teeth. Oral Surgery, Oral Medicine and Oral Pathology 58, 589–99.
Vertucci FJ (2005) Root canal morphology and its relationship to endodontic procedures. Endodontic Topics 10, 3–29.
Vertucci F, Seelig A, Gillis R (1974) Root canal morphology
of the human maxillary second premolar. Oral Surgery,
Oral Medicine and Oral Pathology 38, 456–64.
Wang YL, Chang HH, Kuo CI et al. (2013) A study on the
root canal morphology of primary molars by high-resolution computed tomography. Journal of Dental Sciences 8,
321–7.
Waterhouse PJ, Whitworth JM, Camp JH, Fuks AB (2011)
Pediatric endodontics: endodontic treatment for the primary and young permanent dentition. In: Hargreaves K,
Cohen S, eds. Pathways of the Pulp, 10th edn. St. Louis:
Mosby Elsevier, pp 808–57.
Wrbas KT, Kielbassa AM, Hellwig E (1997) Microscopic studies of accessory canals in primary molar furcations. ASDC
Journal of Dentistry for Children 64, 118–22.
Yang R, Yang C, Liu Y, Hu Y, Zou J (2013) Evaluate root
and canal morphology of primary mandibular second
molars in Chinese individuals by using cone-beam computed tomography. Journal of the Formosan Medical Association 112, 390–5.
International Endodontic Journal, 53, 27–35, 2020
35