This document discusses the root morphology and canal anatomy of several maxillary teeth, including lateral incisors, canines, premolars, and first molars. Some key points discussed include: - Maxillary lateral incisors are typically single-rooted with one canal that is often displaced distolingually. Approximately 10% have accessory canals. - Maxillary canines usually have one canal but may rarely have two canals that join in the apical third. Accessory canals are not uncommon. - Maxillary first premolars most commonly have two roots but can also be single or three-rooted. Over 75% have two canals regardless of root morphology.

1. MAXILLARY LATERAL INCISOR
EXTERNAL ROOT MORPHOLOGY
• The overall average length of the maxillary lateral
incisor is 22 mm with an average crown length of 9 mm
and an average root length of 13 mm
• The maxillary lateral incisors are single-rooted, virtually
100% of the time
• Most reported cases of two-rooted maxillary lateral
incisors are a result of fusion or gemination and are
usually associated with a macrodont crown.
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2. MAXILLARY LATERAL INCISOR
• The root apex and the apical foramen were displaced
distolingually
• The coincidence of the apical foramen and the root
apex was found in only (6.7%) of the specimens.
Therefore, the exploration of the apical foramen and the
constriction with a fine precurved #10 size file tip
and the electronic apex locator, is essential to locate
the foramen.
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3. MAXILLARY LATERAL INCISOR
• the average diameter of the major foramen is 0.4 mm,
while the accessory foramina were 0.2 mm in
diameter.
• The average distance of the major apical foramen from
the anatomical root apex was found to be 0.3 mm.
• Approximately 10% of the maxillary lateral incisors
exhibited accessory foramina.
Apical foramen
Lateral foramen
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4. MAXILLARY LATERAL INCISOR
• An SEM investigation of 14 extracted maxillary
lateral incisors with radicular grooves concluded
that direct communication between the groove
and the pulp was evident in these specimens
and that accessory canals were the primary
mechanism of communication between the
periodontium and the pulp
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5. MAXILLARY LATERAL INCISOR
• An SEM investigation of 14 extracted maxillary
lateral incisors with radicular grooves concluded
that direct communication between the groove
and the pulp was evident in these specimens
and that accessory canals were the primary
mechanism of communication between the
periodontium and the pulp
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6. OEHLERS CLASSIFIED DENS INVAGINATUS INTO THREE TYPES BASED
ON THE SEVERITY OF THE DEFECT.
• Type 1 dens invaginatus is an invagination confined
to the crown.
• Type 2 extends past the cementoenamel junction but
• does not involve periapical tissues.
• Type 3 defect. The invagination extends past the
cementoenamel junction and may result in a second
apical foramen.
1 2 3
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7. In cases of dens invagination :
• Vitality of the pulp in the main canal has been
shown to be maintained while treating (surgically,
nonsurgically, or both) the accessory canal
system, when there has been no communication
between the two
Vital pulp Treatment is on this
accessory canal
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8. MAXILLARY CANINE
• A small percentage of maxillary canines have two
canals(3.5%)
• Of those having two canals, the majority (75%) join in
the apical third and exit through a single foramen
• Accessory (lateral) canals are not uncommon and
become evident radiographically after the completion of
RCT
• The majority of lateral canals occur in the apical third of
the tooth
Lateral canal
radicular-form of
dens invaginatus
type 3.
canine
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9. MAXILLARY CANINE
• One individual with an extremely long root
length was reported by Booth in 1988 with
canine teeth having an overall length of 41 mm.
• This patient was a 31-year-old female of Dutch
origin.
• The total incidence of dens evaginatus has been
shown to be approximately 1%
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10. MAXILLARY FIRST PREMOLAR
• The root anatomy of the maxillary premolar
can vary depending on whether one, two, or
three roots are present .
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11. MAXILLARY FIRST PREMOLAR
There are some common features to the various
forms of maxillary first premolars: The overall
length of the maxillary first premolar is 22.5 mm .
Prominent root concavities are present on both the
mesial and the distal surfaces of the root.
The mesial root concavity is more prominent and
extends onto the cervical third of the crown. This
results in a root that is broad buccolingually and
narrow mesiodistally with a kidney shape when
viewed in cross section at the cementoenamel junction
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12. MAXILLARY FIRST PREMOLAR
The majority of anatomical studies found that the
most common form of the maxillary first
premolar is the two-rooted form.
There was a wide variation
in the incidence of the
number of roots in the
anatomical studies cited.
(three canals in two fused buccal roots
and a lingual root.)
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13. MAXILLARY FIRST PREMOLAR
• The incidence of three-rooted maxillary first
premolars ranged from 0% to 6%
• Single-rooted maxillary first premolars are
the dominant form in Asian population, and
three-rooted forms are rare
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14. MAXILLARY FIRST PREMOLAR
• The majority of maxillary premolars were found to
have two canals, irrespective of whether the tooth
has a single or a double root.
• over 75% of the teeth studied had two canals.
• The incidence of a single canal was significantly
higher in Asian populations compared to the
mixed non-Asian population
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15. MAXILLARY FIRST PREMOLAR
• The Weine type IV root canal system, with a
wide buccolingual canal that branches into two
apical canals and foramina in the apical third,
may sometimes be confused as a taurodont-like
root canal anatomy, when it occurs in single-rooted
maxillary premolar teeth.
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16. MAXILLARY FIRST PREMOLAR
• The Weine type IV root canal system, with a
wide buccolingual canal that branches into two
apical canals and foramina in the apical third,
may sometimes be confused as a taurodont-like
root canal anatomy, when it occurs in single-rooted
maxillary premolar teeth.
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17. MAXILLARY SECOND PREMOLAR
• The root tip usually ends as a single blunt apex,
but it may be :fine and divide into two or more,
(rarely three, apices). The curvature in the apical
third is also not uncommon.
One Canal Dividing in Apical Third
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18. MAXILLARY SECOND PREMOLAR
• The overall average length of the maxillary
second premolar is 22.5 mm with an average
crown length of 8.5 mm and an average root
length of 14 mm .
• The most common form of the maxillary second
premolar is a single root.
• The incidence of two rooted maxillary second
premolars ranged from 5.5% to 20.4%while the
three-rooted form was a rare finding and ranged
from 0% to 1%
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19. MAXILLARY SECOND PREMOLAR
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20. MAXILLARY SECOND PREMOLAR
NOTICE
• Canal exploration of maxillary second premolar
teeth should be done with fine curved files,
keeping in mind the Vertucci or Weine
classification of two canals in one root that
may not be apparent on the radiograph.
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21. MAXILLARY SECOND PREMOLAR
Maxillary left second
premolar with a single
root and a single canal
Maxillary right second premolar
with a single root and single
canal; the apical third exhibits a
curvature to the mesial.
Maxillary left second
premolar with a single
root and a single
main canal; two lateral
(accessory) canals are
visible in the apical third
of the root.
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22. MAXILLARY FIRST MOLAR
• The maxillary first molar normally has three
roots .
• The mesiobuccal root is broad buccolingually
and has prominent depressions
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23. MAXILLARY FIRST MOLAR
• The internal canal morphology is highly variable,
• The majority of the mesiobuccal roots contain
two canals.
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24. MAXILLARY FIRST MOLAR
• The distobuccal root is generally rounded or
ovoid in cross section and usually contains a
single canal.
• The palatal root is more broad mesiodistally
than buccolingually and ovoidal in shape but
normally contains only a single canal
M
D
P
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25. MAXILLARY FIRST MOLAR
• The palatal root generally appears straight on
radiographs, there is usually a buccal curvature
in the apical third.
• The overall average length of the maxillary first
molar is 20.5 mm with an average crown length
of 7.5 mm and an average root length of 13 mm
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26. MAXILLARY FIRST MOLAR
• The maxillary first molar root anatomy is
predominantly a three-rooted form(95%), as shown
in all anatomical studies of this tooth
• The two rooted(3.8%) form is rarely reported and
may be due to the fusion of the distobuccal root to
the palatal root or the fusion of the distobuccal root
to the mesiobuccal root.
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27. MAXILLARY FIRST MOLAR
• The single root or the conical form of root
anatomy in the first maxillary molar is very
rarely reported.
• The four-rooted anatomy in its various forms
is also very rare
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28. MAXILLARY FIRST MOLAR
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29. MAXILLARY FIRST MOLAR
• The mesiobuccal root of the maxillary first
molar contains a double root canal system
more often than a single canal
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30. MAXILLARY FIRST MOLAR
• The mesiobuccal root of the maxillary first
molar contains a double root canal system
more often than a single canal
Pathways of the pulp tenth edition
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31. MAXILLARY FIRST MOLAR
The single-canal system and single apical
foramen in the palatal and the distobuccal root
of the maxillary first molar is the most
predominant form, as reported in all studies,
but multiple canals and more than one apical
foramen variation do exist in 1–3% of these
roots in the weighted studies reported
Two canals in both buccal roots with a
common foramen in each root.
Two separate canals in palatal root
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32. MAXILLARY FIRST MOLAR
Age was found to have an effect on the
incidence of MB2.
 Fewer canals were found in the mesiobuccal
root due to increasing age and calcification.
The MB2 canal was found in (71.1%) when
using SOM and in(62.5%) when using
loupes
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33. MAXILLARY FIRST MOLAR
There are reports of :
1) two palatal canals in three-rooted teeth
2) three palatal canals in a reticular palatal root
3) five roots (two palatal, two mesiobuccal, and one
distobuccal)
4) C-shaped canals .
5) Of all the canals in the maxillary first molar, the
MB2 can be the most difficult to find and negotiate
in a clinical situation
MB
1 2 3
First molar: 6 canals
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34. MAXILLARY SECOND MOLAR
• The maxillary second molar normally has
three roots
• The relative shape of each of the roots is
similar to the maxillary first molar, but the
roots tend to be closer together and there is a
higher tendency toward fusion of two or three
roots.
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35. MAXILLARY SECOND MOLAR
• There is also usually more of a distal
inclination to the root or roots of this tooth
compared to the maxillary first molar
• The mesiobuccal root is broad buccolingually
and has prominent depressions or flutings on its
mesial and distal surfaces.
• The mesiobuccal root has almost an equal
incidence of one or two canals
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36. MAXILLARY SECOND MOLAR
• The distobuccal root is generally rounded or ovoid
in cross section and usually contains a single canal.
• The palatal root is more broad mesiodistally than
buccolingually and ovoidal in shape but normally
contains only a single canal.
• The overall average length of the maxillary second
molar is 19 mm with an average crown length of 7
mm and an average root length of 12 mm
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37. MAXILLARY SECOND MOLAR
• The majority of maxillary second molars (88.6%)
in the anatomical studies were found to be three
rooted.
• The closer proximity of the roots results in a
higher incidence of root fusion (25.8%).
• C-shaped canals(4.9%).
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38. MAXILLARY SECOND MOLAR
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39. MAXILLARY SECOND MOLAR
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40. MANDIBULAR CENTRAL INCISOR
• single-rooted.
• The external form of the root is broad labiolingually
and narrow mesiodistally.
• Longitudinal depressions are present on both the
mesial and the distal surfaces of the root
• A cross section of the root is ovoid to hourglass in
shape
• The overall average length 21.5 mm with an average
crown length of 9 mm and an average root length of
12.5 mm.
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41. MANDIBULAR CENTRAL INCISOR
• All of the anatomical studies reviewed reported that
100% of the mandibular central incisors studied were
single-rooted teeth.
• The canal system is either ovoid or ribbon shaped.
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42. MANDIBULAR CENTRAL INCISOR
• Approximately 12% of the mandibular exhibited
accessory foramina.
• average distance of the apical foramen from the
anatomical root apex was found to be 0.2 mm
Mandibular left central with two
canals and one apex.
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43. MANDIBULAR CENTRAL INCISOR
A few anomalies are reported for this tooth in the
literature:
A. two canals and two separate foramina
B. dens invaginatus
C. fusion
D. Gemination
E. dens evaginatus that includes a lingual talon cusp and a
labial talon cusp
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44. MANDIBULAR LATERAL INCISOR
 The mandibular lateral incisor is single-rooted . and is
comparable in form to the mandibular central incisor.
 The external form of the root is broad labiolingually and
narrow mesiodistally.
 Longitudinal depressions are present on both the mesial and
the distal midroot surfaces of the root
 A cross section of the root is ovoid or hourglass in shape due
to the developmental depressions on each side
 The overall length is 23.5 mm with an average crown length
of 9.5 mm and an average root length of 14 mm
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45. MANDIBULAR LATERAL INCISOR
• All of the anatomical studies reviewed reported that 100%
of the mandibular lateral incisors studied were single-rooted
teeth,
• The shape of the canal system is comparable to the
mandibular central incisor and is either round or ribbon-shaped
two canals and one
apical foramen
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