INTERNAL ANATOMY OF ANTERIOR TOOTH

• Presented by: Jigyasha Timsina Roll no-481 Batch-2011

Goal for the day

• Describe the common shapes of roots in cross section and common canal configurations and variations

• List the average length, number of roots, and most common root curvatures.

Getting started …..

Pulp cavity is the central cavity within the tooth and is entirely enclosed by dentin except at the apical foramen.

The internal anatomy of the tooth does not usually reproduce the simplicity of external anatomy

May be divided into a coronal portion and radicular portion.

4

A pulp horn is an accentuation of the roof of the pulp chamber directly under a cusp or developmental lobe.

A root canal may be divided into three sections namely coronal, middle & apical third.

Accessory canal or lateral canal is a lateral branch of main root canal, generally occuring in the apical third or furcation area of a root.

In anterior teeth the pulp chamber gradually merges into root canal.

In multi-rooted teeth, the pulp cavity consists of a single pulp chamber and usually three root canals.

6

7

Root canal classification

The root canal system is highly complex and canals may branch, divide and rejoin.

Vertucci et al identified and classified eight pulp space configuration which are as following:-

Weine’s Classifiction• Type 1: single canal from pulp chamber to apex

• Type 2: Two canals leaving the chamber and merging to form a single canal short of apex

• Type 3: Two separate and distinct canals from chamber to apex

• Type 4: One canal leaving chamber and dividing into two separate and distinct canals

Alteration in Internal anatomy

• Age

• Irritants

• Calcifications

• Internal Resorption

12

Maxillary central incisor• Average tooth length:22.8 mm

Pulp chamber It is located in the center of crown equidistant from the dentinal wall. It is broad mesio-distally, with its broadest part

incisally. It has three pulp horns that corresponds to the

mamelons in a young tooth.

Root and root canalIt has one root with one root canal.Root canal is broad labio-palatally, conical

in shape, and centrally located.In cross-section, canal is ovoid

mesiodistally in cervical third, rounded in middle third and round in the apical third.

• 17% cases show labial or palatal curvature of the root

• Lateral canals present in about 24% casesAnd when present usually in apical third.

16

Maxillary lateral incisor• Average tooth length: 22.5mm

Pulp chamberThe shape of the pulp chamber is similar to

the maxillary central incisor.It has only two pulp horns, corresponding to

the developmental mamelons.

Root and root canalConfiguration of the root canal is conical

but it has a finer diameter than maxillary central incisor.

In cross-section, the canal is ovoid labio-palatally in the cervical third and ovoid in the middle third & round in the apical third.

• Lateral canals are more frequent (26%)than in maxillary central incisors

• Majority shows distal curve(53%) whereas others are straight.

20

Maxillary canine

• Average tooth length: 26mm

Pulp chamber It has the largest pulp chamber than any single rooted tooth.

Labio-palatally triangular in shape, apex is towards the single cusp and base towards the cervical third of crown.

Mesio-distally it is narrower and may resemble like flame.

In cross-section it is ovoid in shape, with greater diameter labio-palatally.

Only one pulp horn is present.

21

Root and root canal

Single root canal of maxillary cuspid is larger than that of maxillary incisor.

It is wider labio-palatally than its mesio-distal diameter, and on reaching middle third, it taper gradually to an apical constriction.

In cross-section, root canal is ovoid in the cervical and middle third and generally round in the apical third.

• One report stated presence of straight root in 39% cases whereas a distal curve in 32%

• Lateral canals are present in 30% cases

24

Mandibular central incisor• Average tooth length: 20.8mm

Pulp chamberIt is small and flat mesiodistally.Three distinct pulp horns present.Pulp chamber is wide and ovoid labio-

lingually and it tapers incisally..

Root and root canalsIt has one root which is flat and narrow

mesio-distally but wide labio-lingually.

It may have a distal labial curvature.

Canal is broad in the cervical & middle thirds of root in labio-lingual aspect which tapers towards apex

• Canal configuration varies as : one canal exiting in one apical

foramen:70% one canal bifurcating into two

canals ,coming together and exiting into one apical foramen :22%

• A second canal, when present, is lingual to primary canal.

28

Mandibular lateral incisor• Average tooth length: 22.6mm

Pulp chambersSame as mandibular central incisor but it

has larger dimension.

Root and root canalLarger than mandibular central incisor.Majority of root are straight.It may also have distally , labially curved

root as central incisor but the distal curve is sharper.

31

Mandibular canine• Average tooth length: 25mm

Pulp chamberIt is small and flat mesio-distally.One pulp horn is present.It is wide and ovoid mesiodistally and

tapering incisally..

Root and root canal It is usually single rooted. It usually has a single canal exiting in one

apical foramen.Root canal is broad in middle third and

taper to constriction in the apical third in labio-lingual view

• Most of these tooth have single root(68%) but some have a distal curvature(20%)

Concluding

• Of all phases of anatomic study in human system one of the most complex is pulp cavity morphology

• A profound background knowledge of pulp anatomy is a must in success of any endodontic treatment

References

• Grossman’s endodontic practice

• Cohen’s pathways of pulp

• Harty’s text book of endodontic practice

THANK YOU