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TAURODONTISM Term taurodontism originated by Sir Arthur Keith in 1993 to describe a peculiar dental anomaly in which the body of the tooth is enlarged at the expense of the roots.

bull-like teeth its usage derived from the similarity of these teeth to those of ungulated or cud-chewing animals.

taurodontismHypotaurodont mildest formMesotaurodontHypertaurodont extreme form in which the bifurcation or trifurcation occurs near the apices of the roots.CLASSIFICATION (BY SHAW)

A specialised or retrograde characterA primitive patternA mendelian recessive traitAn avastic featureA mutation resulting from odontoblastic deficiency during dentinogenesis of the roots

Possible causes(enumerated by Mangion)Hammer and his associates believe that it is caused by failre of Hertwigs epithelial sheath to invaginate at the proper horizontal level.Goldstein and Gottleib have stated that the condition appears to be genetically controlled and familial in nature.ContdA case of taurodontism occur in concomitantly with amelogenesis imperfecta has been reported by Crawford.It has been reported that many patients with the Klinefelter syndrome exhibit taurodontism,but it is not a constant feature of this syndrome.For this reason,Gardner and Girgis have recommended that male patients exhibiting taurodontism should have chromosomal studies performed,esp,if there is any nonspecific diagnosis of mental retardation and if the patient has a tall,thin appearance with long arms and a prognathic jaw.ContdIt may affect either the deciduous or permanent dentition,although permanent tooth involvement is more common.Teeth involved are almost invariably molars.Single tooth/several molars in the same quandrant/unilateral/bilateral involvement.The teeth themselves have no remarkable or unusual morphologic clinical characteristics.

CLINICAL FEATURESInvolved teeth rectangular in shape rather than taper towards the roots.Large pulp chamber with a much greater apico-occlusal height than normal.Pulp lacks usual constiction at the cervical of the tooth and the roots are exceedingly short.The bifurcation or trifurcation may be only a few millimeters above the apices of the roots. Radiographic features

radiograph

radiographNo specific treatment is required for the anomaly.TreatmentCLINICAL CONSIDERATION

The clinical implication of taurodontism has potentiallyincreased risk of pulp exposure because of decay anddental procedures. Taurodontism may complicate orthodonticand/or prosthetic treatment planning. Taurodontism,although not very common has to be emphasizeddue to its influence on various dental treatments.

Endodontic considerations:

A taurodont tooth shows wide variation in the size and shape of the pulp chamber,varying degrees of obliteration and canal configuration,apically positioned canal orifices, and the potential foradditional root canal systems13From an Endodontists view, taurodontism presents achallenge during negotiation, instrumentation and obturationin root canal therapy.

Because of the complexityof the root canal anatomy and proximity of buccal orifices,complete filling of the root canal system in taurodontteeth is challenging.

A modified filling technique,which consists of combined lateral compaction in theapical region with vertical compaction of the elongatedpulp chamber, has been proposed.

In addition to thedifficulty of the endodontic procedure, a recent case reportsuggests the possibility of taurodont teeth having anextraordinary root canal system which is challenging forendodontists.Recently, a case report highlights the use of high-enddiagnostic imaging modalities such as spiral computerizedtomography in making a confirmatory diagnosis ofthe multiple morphologic abnormalities such as taurodontism,dens invaginatus, pyramidal cusps of the premolars,dens evaginatus.The endodontic therapy of choice in these situations willbe conservative. Therefore, root canal treatment becomesa challenge.

Though taurodontism is of rare occurrence,the clinician should be aware of the complex canalsystem for its successful endodontic management.

Pre-operative radiograph of maxillary right first molar.

Radiograph of contra lateral maxillary left first molar.

Radiograph upon completion of root canal filling.Surgical considerations: The extraction of a taurodonttooth is usually complicated because of shift in the furcationto apical third .

In contrast, it has also beenhypothesized that the large body with little surface areaof a taurodont tooth is embedded in the alveolus.

Thisfeature would make extraction less difficult as long asthe roots are not widely divergent.

It is reported thatextraction of such teeth may not be a problem unless theroots are not widely divergent. However, some authorsbelieve that hypertaurodonts may pose some problem syndrome .From a periodontal standpoint,taurodont teeth may, in specific cases, offer favorableprognosis.

Where periodontal pocketing or gingivalrecession occurs, the chances of furcation involvementare considerably less than those in normal teeth becausetaurodont teeth have to demonstrate significant periodontaldestruction before furcation involvement occurs.

It is very important for a general dental practitioner tobe familiar with taurodontism not only with regards toclinical complications but also its management. Taurodontismalso provides a valuable clue in detecting itsassociation with many syndromes and other systemicconditions.

Periodontal considerations: For the prosthetic treatment of a taurodont tooth, it has been recommended that postplacement be avoided for tooth reconstruction .

Because less surface area of the tooth is embedded inthe alveolus, a taurodont tooth may not have as muchstability as a cynodont when used as an abutment foreither prosthetic or orthodontic purposes. The lackof a cervical constriction would deprive the tooth ofthe buttressing effect against excessive loading of the crown.

Prosthetic considerations:

Variable dimensions for establishing the taurodontism index:vertical height of the pulp chamber (V1), distance between the lowestpoint of the roof of the pulp chamber to the apex of the longest root(V2), and distance between the baseline connecting the two CEJ andthe highest point in the floor of the pulp chamber (V3). Establishing acondition of taurodontism is made when V1 is divided by V2 andmultiplied by 100 if above 20, and V3 exceeds 2.5 mm: (V1/V2) * 100 20 and V3 2.5 mm. Taurodontic index (TI) V1/V2 100. Degrees of taurodontism were determined as:hypotaurodontism: TI 2030, mesotaurodontism: TI 3040, and hypertaurodontism:TI 4075 (5). In this case,