Taurodontism: A dental rarity

Abstract

Taurodontism is a developmental disturbance of a tooth in which body is enlarged at the expense of the roots. An enlarged pulp chamber, apical displacement of the pulpal floor and lack of constriction at the cementoenamel junction are the characteristic features. It appears most frequently as an isolated anomaly. But its association with several syndromes and abnormalities has also been reported. Endodontic treatment of taurodont teeth is stated to be complex and difficult due to the complexity in the tooth morphology. This case report presents a case of taurodontism in permanent maxillary molars and their successful endodontic treatment.

Full text

Journal of Oral and Maxillofacial Pathology Vol. 17 Issue 3 Sep - Dec 2013
INTRODUCTION
Dental morphological triats are of particular importance in
the study of phylogenetic relationships and the population
ofnities. One of the most important abnormalities in
the tooth morphology is taurodontism. Taurodontism is a
morpho‑anatomical change in the shape of the tooth which
usually occurs in the multirooted teeth. An enlarged body and
the pulp chamber as well as apical displacement of the pulpal
oor are the characteristic features.[1]
The term taurodontism comes from the Latin term tauros which
means bull and the Greek term odus which means tooth (or)
bull tooth. It was rst described by Gorjanovic‑Kramberger.[2]
However, the term traurodontism was rst introduced by Sir
Arthur Keith in 1913 to describe molar teeth resembling those
of ungulates particularly bulls. The etiology of taurodortism is
unclear. It is thought to be caused by the failure of Hertwig’s
epithelial sheath diaphragm to invaginate at the proper
horizontal level, resulting in a tooth with short root, enlarged
body, an enlarged pulp and normal dentin.[1]
Previously, taurodontism was related to syndromes such
as Klinefelter’s and Down’s. Today it is considered as an
anatomic variance that could occur in a normal population.
Taurodontism has been graded according to its severity as least
pronounced (hypotaurodontism), moderate (mesotaurodontism)
and most severe (hypertaurodontism). Shifman and Channel[3]
also included an index to calculate the degree of taurondontism
as shown radiographically [Figure 1].
Taurodontism although not common, a preoperative
radiograph serve as an important tool for diagnosing the
taurodontic condition and helps in preventing unexpected
challenges while performing successful endodontic therapy.
The present case describes successful endodontic management
of maxillary rst molar with taurodontism.
CASE REPORT
A 25‑year‑old male patient was referred to Department of
Conservative Dentistry and Endodontics, for the treatment
of upper right and left rst molar teeth. Intraoral examination
revealed fracture of the palatal cusps with respect to 16 and
buccal cusp fracture with respect to 26 [Figure 2]. At the time
of examination, the teeth were asymptomatic. The teeth were
not sensitive to percussion or palpation. Intraoral examination
revealed a normal‑shaped crown. Periodontal probing was
within the normal range. Patient’s medical history was
noncontributory. Upon vitality testing, 26 showed positive
response to thermal and electric pulp testing. The 16 showed
no response to thermal and electric pulp testing indicating
necrotic pulp. Intraoral periapical radiograph of 16 showed
huge pulp chamber extending beyond the cervical area
reaching the furcation in the apical third region [Figure 3].
Three short roots were seen at the furcation area in the
apical third indicating hypertaurodontism. The intraoral
periapical radiograph of contralateral 26 revealed similar
ndings [Figure 4]. The diagnosis of hypertaurodontism for
Taurodontism: A dental rarity
CM Jayashankara, Anil Kumar Shivanna, KS Sridhara1, Paluvary Sharath Kumar
Departments of Conservative Dentistry and Endodontics, Sri Siddhartha Dental College, Tumkur, 1Krishnadevaraya College of Dental
Sciences, Yelahanka, Bangalore, Karnataka, India
CASE REPORT
Address for correspondence:
Dr. Anil Kumar Shivanna,
# 73, First Cross, Leelavathi Extension,
Maddur ‑ 571 428, Karnataka, India.
E‑mail: anilendo@yahoo.com
ABSTRACT
Taurodontism is a developmental disturbance of a tooth in which body
is enlarged at the expense of the roots. An enlarged pulp chamber, apical
displacement of the pulpal oor and lack of constriction at the cementoenamel
junction are the characteristic features. It appears most frequently as an
isolated anomaly. But its association with several syndromes and abnormalities
has also been reported. Endodontic treatment of taurodont teeth is stated to
be complex and difcult due to the complexity in the tooth morphology. This
case report presents a case of taurodontism in permanent maxillary molars
and their successful endodontic treatment.
Key words: Bull tooth, karyotype, taurodontism
Access this article online
Quick Response Code:
Website:
www.jomfp.in
DOI:
10.4103/0973-029X.125227
[Downloaded free from http://www.jomfp.in on Monday, April 2, 2018, IP: 43.239.115.48]

Journal of Oral and Maxillofacial Pathology: Vol. 17 Issue 3 Sep - Dec 2013
Taurodontism Jayashankara, et al.
the present case was made based on the radiographic nding
and taurodont index as proposed by Shiffman and Chanannel
[Figure 1].
Endodontic management
The tooth was anesthetized with lidocaine 2% with epinephrine
1:1, 00,000 (Lignox 2% A Warren India). Magnifying
loupes (Carl Zeiss, India) were used throughout the procedure
to facilitate visualization. The tooth was isolated and access
cavity prepared. The pulp tissue which was voluminous was
extirpated. A total of 2.5% of sodium hypochlorite was used
as irrigating solution. The furcation area was situated in the
apical third region and three canal orices were located at the
furcation area; palatal, mesiobuccal and distobuccal.
Working length determination was performed using electronic
apex locator Propex II (Dentsply Maillefer, Switzerland,
USA) and was conrmed with a radiograph [Figure 5]. After
working length determination the instrumentation of the
canals was done to size 40 for the palatal canal and up to size
30 for the mesial canals using RC prep (Premier, Ultradent,
USA) as a lubricanting agent.
A modied obturation technique was used because of
complexity of inner root canal anatomy. This consisted of
combined lateral condensation of the gutta percha in the apical
part with vertical compaction of the remaining pulp chamber.
AH‑plus (Dentsply, Switzerland, USA) was used as a root
canal sealer. The nal radiograph conrmed well‑obturated
root canal system [Figure 6].
DISCUSSION
The taurodont tooth shows wide variation in the size of the
pulp chamber, varying degrees of canal conguration like
apically displaced furcation with a shorter root length and a
Figure 2: Palatal cusp fracture in relation to 16 and buccal cusp
fracture in relation to 26
Figure 1: Taurodontism index: vertical height of the pulp chamber (1)
distance between the lowest point of the roof of the pulp chamber to
the apex of the longest root (2) and distance between the baseline
connecting the two cement‑enamel junction and the highest point in
the oor of the pulp chamber (3). Establishment of a condition of
taurodontism is made when1/2 multiplied by 100 is above 20, and 3
exceeds 2.5 mm: (1/2)* 100 > 20 and 3 > 2.5 mm. Taurodontic index
(TI) = 1/2 × 100. In this case TI= 61 and 3= 8 mm, clearly indicating
hypertaurodontism
Figure 3: Preoperative radiograph of maxillary right rst molar
Figure 4: Radiograph of the contralateral maxillary left rst molar
[Downloaded free from http://www.jomfp.in on Monday, April 2, 2018, IP: 43.239.115.48]

Journal of Oral and Maxillofacial Pathology: Vol. 17 Issue 3 Sep - Dec 2013
Taurodontism Jayashankara, et al.
less marked cervical constriction. The triat is usually seen in
both permanent and primary teeth and is believed to be caused
by failure of Hertwig’s epithelial root sheath to invaginate at
the proper horizontal level.[4] The reported rate of occurrence
ranges from 0.57% to 4.37%. Taurodontism appears most
frequently as an isolated anomaly; it has also been associated
with several syndromes and anomalies including Klinefelter’s,
Down’s, tricho‑dento‑osseous syndrome and others.
Taurodontism is a dental anamoly characterized by a
distinct morphology.[6] In general, patient with more severe
forms of the triat (meso or hyper) are more likely to have
X‑chromosomal aneuploidy. Varrela et al.,[5] supported the
concept that prevalence of taurodontism increases as the
number of X‑chromosomes increases and also indicate that
expression of the triat and the number of X‑chromosomes
may be positively correlated. They have further suggested
that X‑chromosomal gene inuencing development of enamel
may also be involved in the development of taurodontism.[5]
Figure 5: Working length radiograph Figure 6: Obturation radiograph
Figure 7: Karyotype from peripheral blood‑Normal (46 XY)
Gardner and Girgis recommend that patients with meso‑ or
hypertaurodontic teeth who do not have a syndrome known
to be associated with taurodontic teeth should be consulted
for chromosome analysis, as there is a high association
of taurodontic teeth with X‑chromosome aneuploidy
syndromes.[6]
In the present case, karyotype of the patient was studied to
rule out the possibility of chromosomal aberrations. The
results of the karyotype study showed no chromosomal
aberrations [Figure 7].
The endodontic treatment in taurodont teeth has been described
as complex and difcult. Durr et al.,[7] suggested that complexity
in the morphology could hamper the location of the orices thus
creating difculty in instrumentation and obturation.
The contributing factors for the successful endodontic
treatment in such cases include careful exploration of the
[Downloaded free from http://www.jomfp.in on Monday, April 2, 2018, IP: 43.239.115.48]

Journal of Oral and Maxillofacial Pathology: Vol. 17 Issue 3 Sep - Dec 2013
Taurodontism Jayashankara, et al.
grooves between all the orices particularly with magnication,
ultrasonic irrigation and modied obturation techniques.[8]
In the present case also success in the root canal treatment
was mainly attributed to use of magnifying loops for better
visualization, use of 2.5% of sodium hypochlorite to dissolve
the pulp tissue and was followed by modied obturation
technique to achieve three‑dimensional obturation of root
canal system.
Another endodontic challenge related to taurodontism is
intentional replantation. The extraction of taurodont tooth
is usually complicated because of dilated apical third. In
contrast, it has also been hypothesized that because of its large
body, little surface area of the taurodont tooth is embedded in
the alveolus. This feature would make extraction less difcult
as long as roots are not widely divergent.[9]
From the periodontal stand point, taurodont teeth may in
specic cases offer favorable prognosis. Here, the chances
of furcation involvement are considerably less than those in
normal teeth. Because taurodont teeth have to demonstrate
signicant periodontal destruction before the furcation
involvement occurs.[10]
CONCLUSION
Although taurodontism is a dental rarity, this unusual radicular
form showed merit circumspect consideration in treatment
planning. The thorough knowledge of etiology, anatomic and
radiographic features and its association with other syndromes
of the dental rarity should be well‑understood. Also, important
consideration in performing endodontic treatment of such
rarity is mandatory due to complexity of the root canal system.
REFERENCES
1. Rajendran R. Developmental disturbances of oral and paraoral
structures. In: Shafer’s Text Book of Oral Pathology. 7th ed. New
Delhi (India); Elsevier ( Reed Elsevier India):2009. p. 45..
2. Gorjanovic‑Kramberger K. On prismatic molar roots of recent
and diluvial man. Anat Anz 1908;32:401‑13.
3. Shifman A, Chanannel I. Prevalence of taurodontism found in
radiographic dental examination of 1,200 young adult Israeli
patients. Community Dent Oral Epidemiol 1978;6:200‑3.
4. Bhatri R, Chandra A, Trikku AP, Wadhwani KK. “Taurodontism”
and endodontic challenge: A case report. J Oral Sci
2009;51:471‑4.
5. Yeh SC, Hsu TY. Endodontic treatment in taurodontism with
Klinefelter’s syndrome: A case report. Oral Surg Oral Med Oral
Pathol Oral Radiol Endod 1999;88:612‑5.
6. Joseph M. Endodontic treatment in three taurodontic teeth
associated with 48, XXXY Klinefeltors syndrome: A review and
case report. Oral Surg Oral Med Oral Pathol Oral Radiol Endod
2008;105:670‑7.
7. Durr DP, Campos CA, Ayers CS. Clinical signicance of
taurodontism. J Am Dent Assoc 1980;100:378‑81.
8. Varrela J, Alvesalo L, Maghall J. Taurodontism in 45, X females.
J Dent Res 1990;69:494‑5.
9. Varrela J, Alvesalo L. Taurodontism in 47, XXY males: An
effect of the extra X chromosome on root development. J Dent
Res 1988;67:501‑2.
10. Satyanarayanan R, Carounanidy U. Taurodontism–review and
an Endodontic case report. Endodontology 2001;13:8‑10.
How to cite this article: Jayashankara CM, Shivanna AK, Sridhara
KS, Kumar PS. Taurodontism: A dental rarity. J Oral Maxillofac Pathol
2013;17:478.
Source of Support: Nil. Conict of Interest: None declared.
[Downloaded free from http://www.jomfp.in on Monday, April 2, 2018, IP: 43.239.115.48]