Ce diaporama a bien été signalé.
Nous utilisons votre profil LinkedIn et vos données d’activité pour vous proposer des publicités personnalisées et pertinentes. Vous pouvez changer vos préférences de publicités à tout moment.
ROOT CANAL
MORPHOLOGY
Dr.Nidhi Shrivastava
PG Student 2nd year
Department of Conservative Dentistry And Endodontics
PDA
Contents
•Introduction
•Weine’s classification
•Vertucci’s classification
•Morphology of root apex
•Morphology of maxillar...
Introduction
4
Accessory canals occur in three distinct patterns in the
mandibular first molars.
A, In 13% a single furcation canal ext...
Weine’s classification
Type I – single canal from pulp chamber to apex;
Type II – two canals leaving the chamber and mergi...
Vertucci’s classification
Sert and Bayirli’s
additional canals to
Vertucci’s
classification
8
Morphology of root apex
Minor apical diameter
Or apical constriction
Major apical diameter
Or apical foramen
9
Isthmus
An isthmus is a narrow,
ribbon-shaped
communication
between two root
canals that contains
pulp or pulpally deriv...
Maxillary Central Incisor
average time of eruption, 7 to 8 years;
average age of calcification, 10 years;
average length, ...
11
Maxillary lateral Incisor
average time of eruption, 8 to 9 years;
average age of calcification, 11 years;
average length, ...
13
Variations
• Presence of lingual radicular or developmental
groove :
• May be present in all anterior teeth, but more
comm...
Maxillary canine
Development and anatomic data:
average time of eruption, 10 to 12 years;
average age of calcification, 13...
16
Maxillary first premolar
Average time of eruption, 10 to 11 years;
average age of calcification, 12 to 13 years;
average l...
18
• Palatal canal is largest, directly under the palatal cusp.
• Buccal canal is under the buccal cusp.
• When single canal,...
Variations
• Ethnic differences were demonstrated for maxillary
first premolar root number in anatomical studies
reported....
Maxillary second premolar
.
Average time of eruption, 10 to 12 years;
average age of calcification, 12 to 14 years;
averag...
22
• Root and Root canals:
• Have a single root (90.3%); Two well developed roots (2%); Two
roots partially fused (7.7%).
• R...
Variations
• The case reports include examples of dens
invaginatus, a deep distal root concavity,
taurodontism, two roots ...
25
The most common root morphology of the first premolars
was the classical two separate root morphology (a Caucasian
trai...
Maxillary first molar
Average time of eruption, 6 to 7 years;
average age of calcification, 9 to 10 years;
average length,...
27
• Palatal orifice is the largest, round or oval in shape and
easily accessible.
• The mesiobuccal orifice is under the mes...
Variations
• The root and root canal morphology of teeth varies greatly in
the reported literature.
• Many studies provide...
• Age was found to have an effect on the
incidence of MB2.
• Sert and Bayirli conducted a clearing study
that identified g...
• In 2006, Cleghorn et al. reviewed the literature
with respect to the root and canal systems in
maxillary first molars.
•...
• The canal morphology of the distobuccal and
palatal roots was reported in 14 studies that
included 2576 teeth.
• The mos...
• C-shaped canals are very rare in maxillary first
molars, with an incidence of about 0.1%.
• C-shaped root canal morphoty...
34
Category I (C1): The shape is an uninterrupted “C” with no
separation or division .
Category II (C2): The canal shape r...
• Maxillary first molars with two palatal roots
were described by Stone & Stroner, Hulsmann,
Baratto-Filho et al., and Bar...
• Single palatal roots with two separate canals
were reported by Thews et al., Stone & Stroner,
and Hartwell & Bellizzi.
•...
37
Single-rooted first and second molars commonly showed types I,
IV (0.5%) and type III (1%) canal systems, respectively....
Maxillary second molar
Average time of eruption, 11 to 13 years;
average age of calcification, 14 to 16 years;
average len...
39
• Roots and Root Canals:
Usually has three roots close together.
• All the three roots may fuse together to form a single
...
Variations
• Most studies concerning the canal morphology of
maxillary second molars reported that the majority of
these t...
• Zmener & Peirano, Fahid & Taintor, and
Jafarzadeh et al. described cases with three
buccal roots fully separated.
• Alan...
• Vertucci investigated the canal configuration of
100 maxillary second molars and found, in the
mesiobuccal root,
• One c...
Mandibular incisors
Average time of eruption, 6 to 8 years;
average age of calcification,
9 to 10 years;
average length: 2...
45
• Root and Root Canals:
• 1 - 1 (70%).
• 1 – 2 (22%),
• 2 – 2 (3%).
• Root canal is broad Labio-lingually in cervical
and ...
Variations in Mandibular Central and Lateral Incisors
• The morphology of mandibular central and lateral
incisors is very ...
• Vertucci studied the root canal morphology of
300 extracted mandibular anterior teeth and
found two canals in 30% of man...
• In an investigation on 100 mandibular anterior
teeth, Kartal & Yanikoglu identified two new root
canal types, which had ...
50
Mandibular canine
Average time of eruption, 9 to 10 years;
average age of calcification, 13 years;
average length, 25.6...
51
• Pulp Chamber:
• Resembles Maxillary Canine (smaller in dimensions).
• Pulp chamber is narrow mesio-distally.
• Labio-lin...
Variations
• Pecora et al. studied the internal anatomy,
direction, and number of roots of 830 extracted
mandibular canine...
54
Mandibular first premolar
Average time of eruption, 10 to 12 years;
average age of calcification, 12 to 13 years;
avera...
55
Pulp Chamber:
•Mesiodistal width of the pulp chamber in narrow.
•Buccolingually ,the pulp chamber is wide, with a prominen...
• Root and Root Canals:
• Usually has a short conical root and may divide in the apical third
into 2-3 roots.
• Root usual...
Variations
• In a literature review published by Cleghorn et
al. approximately 98% of the 6700 teeth
analyzed were single-...
• Studies of the internal canal morphology revealed that
a single canal was present in 75.8% of the teeth.
• Two or more c...
• In a study of mandibular first premolars in a
Chinese population using the cross-section
method, Lu et al. found
• A sin...
• Uncommon but possible morphological
anomalies of the mandibular first premolar
are
• Two canals in two roots,
• Three ca...
62
Mandibular second premolar
Average time of eruption, 11 to 12 years;
average age of calcification, 13 to 14 years;
Aver...
63
Pulp Chamber:
Similar to that of mandibular first premolar, except
that of the lingual horn is more prominent under a
well...
Variations
• Vertucci found that the second premolar had one
root canal at the apex in 97.5% of the teeth
studied and two ...
• Cases with four canals were reported by Bram
& Fleisher, Holtzman, and Rhodes.
• A case of a mandibular second premolar ...
67
Mandibular first molar
Average time of eruption, 6 years;
average age of calcification, 9 to 10 years;
average length, ...
68
Pulp Chamber:
The roof of the pulp chamber is often rectangular in shape.
The mesial wall is straight, the distal wall rou...
• Three distinct orifices are present in the pulpal
floor: ML, MB and Distal.
• The MB orifice is under the MB cusp, the M...
• Root and Root canals.
• Usually two well differentiated roots, a third root may
be found in some cases either distally o...
• Three canals are usually present,
• Mesial root, 2-2 (41%); 2-1 (28%); 2-1-2 (10%);
1-1 (12%); 1-2 (8%); rarely 3-3.
• D...
Variations
• In a Caucasian population, the majority of
mandibular first molars are two-rooted, with
various canal configu...
• In other studies, the frequency of a middle mesial canal
in the mesial root of mandibular molars varies between
1% and 7...
• Distal roots of mandibular first molars, in ethnic
Europeans, have
• One single canal in about 70% of teeth,
• Two canal...
• A major variant of the two-rooted morphology
in the mandibular first molar is the presence
of a supernumerary root locat...
• The rate of occurrence of this root dysmorphia in
Caucasians and Africans is less than 5%,
• Whereas in populations with...
Mandibular second molar
Average time of eruption, 11 to 13 years;
average age of calcification, 14 to 15
years;
average le...
79
• Root and Root canals:
Majority have two roots (71%); 1 root (27%) and 3 roots (2%).
• In single rooted, straight (53%); ...
• If 2 roots, mesial root usually curves distally
(61%); straight (27%); bucally (4%); S or Bayonet
shape (6%).
• Three ro...
Variations
• In a study on 149 mandibular second molars,
Manning found that
• 76% of the teeth had two roots,
• 22% had on...
• In a study on 100 mandibular second molars,
for the mesial root, Vertucci reported
• a single canal in 27% of the teeth,...
• In the distal root, Vertucci found a
• single canal in 92% of the teeth,
• two canals joining in 3%, and
• two separate ...
85
Types of pulpal floor. M, Mesial side; D, distal side.
(From Min Y, Fan B, Cheung G, Gutmann J, Fan M: J Endod 32, 1155...
86
Three-dimensional classification of C-shaped canal configuration.
A, Merging type; B, symmetrical type; C, asymmetrical...
87
Morphological changes
Invaginations
• Dens Invaginatus :
• Classified into three types based on severity, from
simple to complex.
• Type 1 – inv...
Invaginations
Pulp stones(denticles)
Changes in morphology due to aging
Curved canals
Conclusion
• Deviations from normal anatomy of root canal
system is rare but should be suspected if
visible on radiographs...
• The clinicians should be attentive to the signs of
anatomical variation.
• Bleeding from pulp chamber may reveal the
pre...
References
• Cohen , Pathways of the pulp,10th edition
• Ingle , Endodontics 6th edition
• Ingle , Endodontics 5th edition
Prochain SlideShare
Chargement dans…5
×

Root canal morphology nidhi

dental

Livres associés

Gratuit avec un essai de 30 jours de Scribd

Tout voir

Livres audio associés

Gratuit avec un essai de 30 jours de Scribd

Tout voir
  • Soyez le premier à commenter

Root canal morphology nidhi

  1. 1. ROOT CANAL MORPHOLOGY Dr.Nidhi Shrivastava PG Student 2nd year Department of Conservative Dentistry And Endodontics PDA
  2. 2. Contents •Introduction •Weine’s classification •Vertucci’s classification •Morphology of root apex •Morphology of maxillary teeth •Morphology of mandibular teeth •Morphological changes •Conclusion •References
  3. 3. Introduction
  4. 4. 4 Accessory canals occur in three distinct patterns in the mandibular first molars. A, In 13% a single furcation canal extends from the pulp chamber to the intraradicular region. B, In 23% a lateral canal extends from the coronal third of a major root canal to the furcation region (80% extend from the distal root canal). C, About 10% have both lateral and furcation canals.
  5. 5. Weine’s classification Type I – single canal from pulp chamber to apex; Type II – two canals leaving the chamber and merging to form a single canal short of the apex; Type III – two separate and distinct canals from chamber to apex; Type IV – one canal leaving the chamber and dividing into two separate and distinct canals.
  6. 6. Vertucci’s classification
  7. 7. Sert and Bayirli’s additional canals to Vertucci’s classification
  8. 8. 8 Morphology of root apex Minor apical diameter Or apical constriction Major apical diameter Or apical foramen
  9. 9. 9 Isthmus An isthmus is a narrow, ribbon-shaped communication between two root canals that contains pulp or pulpally derived tissue Schematic representation of isthmus classifications described by Kim et al Type I is an incomplete isthmus; faint communication between two canals. Type II is two canals with a definite connection between them (complete isthmus). Type III is a very short, complete isthmus between two canals. Type IV is a complete or incomplete isthmus between three or more canals. Type V is marked by two or three canal openings without visible connections.
  10. 10. Maxillary Central Incisor average time of eruption, 7 to 8 years; average age of calcification, 10 years; average length, 22.5 mm. Root curvature (most common to least common): straight, labial, distal.
  11. 11. 11
  12. 12. Maxillary lateral Incisor average time of eruption, 8 to 9 years; average age of calcification, 11 years; average length, 22 mm. Root curvature (most common to least common): distal, straight.
  13. 13. 13
  14. 14. Variations • Presence of lingual radicular or developmental groove : • May be present in all anterior teeth, but more common in maxillary lateral. • The groove can loose its periodontal attachment as a result of both periodontal and endodontic etiologies. • There is generally direct communication between the groove and the pulp cavity and this occurs primarily through dentinal tubules. Gandhi, A., Kathuria, A. and Gandhi, T. (2011), Endodontic-periodontal management of two rooted maxillary lateral incisor associated with complex radicular lingual groove by using spiral computed tomography as a diagnostic aid: a case report. International Endodontic Journal, 44: 574–582.
  15. 15. Maxillary canine Development and anatomic data: average time of eruption, 10 to 12 years; average age of calcification, 13 to 15 years; Average length, 26.5 mm. Root curvature (most common to least common): distal, straight, labial.
  16. 16. 16
  17. 17. Maxillary first premolar Average time of eruption, 10 to 11 years; average age of calcification, 12 to 13 years; average length, 20.6 mm. Root curvature (most common to least common): buccal root—lingual, straight, buccal palatal root—straight, buccal, distal single root—straight, distal, buccal.
  18. 18. 18
  19. 19. • Palatal canal is largest, directly under the palatal cusp. • Buccal canal is under the buccal cusp. • When single canal, canal is ovoid in shape, wider buccopalatally than mesiodistally in cervical and middle thirds and round in apical third. • When 2 root canals are present, cervical third is ovoid, round in mid-root, round and small in apical third. • In teeth with a single root, majority are straight (38.4%); distal curve (36.8%); buccal curve (14.4%); palatally (2.4%); S or Bayonet shape (8%). • In double rooted teeth, buccal roots are straight (27.8%); palatal curve (8.3%); distal curve (14%); S or Bayonet shape (5.5%).
  20. 20. Variations • Ethnic differences were demonstrated for maxillary first premolar root number in anatomical studies reported. • The study by Loh reported a much lower incidence (50.6%) of the two-rooted maxillary first premolars in a Singaporean population compared to Sabala’s study (98.4%) in the United States. • Tratman reported that the two-rooted first premolar was very uncommon in Asian stock as did Petersen in his study of the East Greenland Eskimo dentition.
  21. 21. Maxillary second premolar . Average time of eruption, 10 to 12 years; average age of calcification, 12 to 14 years; average length: 21.5 mm. Root curvature (most common to least common): distal, bayonet, buccal, straight.
  22. 22. 22
  23. 23. • Root and Root canals: • Have a single root (90.3%); Two well developed roots (2%); Two roots partially fused (7.7%). • Roots are Straight (37.4%); distal curve (33.9%); buccal curve (15.7%); S or Bayonet shaped (13%). • In cross section, • Cervical third – ovoid and narrow; • middle third – ovoid (when one canal), round (when two canals); • apical third – round. Pulp Chamber: Pulp horns under each cusp, Pulp chamber narrow mesio- distally, wider bucco-palatally than the first Pre-molar and shows two horns. •Roof of the pulp chamber is similar to first pre-molar but deeper if two canals are present. •In cross section, pulp chamber is narrow and ovoid in shape
  24. 24. Variations • The case reports include examples of dens invaginatus, a deep distal root concavity, taurodontism, two roots and three canals (but not as common as in 1st premolar). • When three canals are present, the external outline form becomes triangular with the base on the buccal aspect. • The mesiobuccal and distobuccal corners of the triangle should be positioned directly over the corresponding canal orifices.
  25. 25. 25 The most common root morphology of the first premolars was the classical two separate root morphology (a Caucasian trait) and that of the second premolars was a single-root morphology (a Mongoloid trait), The buccal roots of the first premolar showed the maximum variation, the most common being type I (Vertucci’s classification), followed by type IV. The highest incidence of intercanal communications was found in the single-rooted first premolars. All roots exhibiting type IV and V canal configurations showed two separate apical foramina, while additional type 2–3 canal configurations showed three separate apical foramina. The root number and morphology as well as the canal morphology of Indian maxillary premolars showed both Mongolian and Caucasian traits. Prasanna Neelakantan, Chandana Subbarao, Roshni Ahuja, Root and canal morphology of Indian maxillary premolars by a modified root canal staining technique Odontology, 2011, Volume 99, Number 1, Page 18
  26. 26. Maxillary first molar Average time of eruption, 6 to 7 years; average age of calcification, 9 to 10 years; average length, 20.8 mm. Root curvature (most common to least common): mesiobuccal root—distal, straight; distobuccal root—straight, mesial, distal palatal root—buccal, straight.
  27. 27. 27
  28. 28. • Palatal orifice is the largest, round or oval in shape and easily accessible. • The mesiobuccal orifice is under the mesiobuccal cusp, is long buccopalatally and may have a depression at the palatal end in which the orifice of the fourth canal may be present. • The distobuccal orifice is located slightly distal and palatal to the mesiobuccal orifice. Pulp Chamber: •Largest in the dental arch, 4 pulp horns. •Pulpal roof – rhomboid in cross section, the four walls forming the roof converge towards the floor where the lingual wall almost disappears giving the floor a triangular form. •Floor is present in the cervical third of the root. •Orifices being located at three angles of the triangle.
  29. 29. Variations • The root and root canal morphology of teeth varies greatly in the reported literature. • Many studies provided no information on ethnic background, age or gender or possible explanations for variations observed. • A study by Weine et al. determined that incidence of MB2 in a Japanese population was similar to the incidence reported for other ethnic backgrounds.
  30. 30. • Age was found to have an effect on the incidence of MB2. • Sert and Bayirli conducted a clearing study that identified gender, in a sample of 2800 teeth from Turkish patients. A single Vertucci Type 1 canal was present in only 3% of males as compared to 10% of females.
  31. 31. • In 2006, Cleghorn et al. reviewed the literature with respect to the root and canal systems in maxillary first molars. • The results of this study indicated that maxillary first molars had three roots in 96.2% of the 416 teeth examined. • Two roots were found in 16 (3.8%) of the teeth studied. • The incidence of one root or four roots was very rare. • Fusion of two or more roots occurred approximately 5.2% of the time.
  32. 32. • The canal morphology of the distobuccal and palatal roots was reported in 14 studies that included 2576 teeth. • The most common canal system configuration of the disto-buccal root was a single canal (98.3%). • Two canals were found 1.7% of the time. • A single apical foramen was present 98% of the time. • The palatal root had a single canal and a single foramen 99% and 98.8% of the time, respectively.
  33. 33. • C-shaped canals are very rare in maxillary first molars, with an incidence of about 0.1%. • C-shaped root canal morphotypes result from a fusion of the disto-buccal and palatal roots and may extend to the apical third of the fused roots.
  34. 34. 34 Category I (C1): The shape is an uninterrupted “C” with no separation or division . Category II (C2): The canal shape resembles a semicolon resulting from a discontinuation of the “C” outline , but either angle α or β should be no less than 60 degrees. Category III (C3): Two or three separate canals and both angles, α and β, are less than 60 degrees. Category IV (C4): Only one round or oval canal is in the cross- section . Category V (C5): No canal lumen can be observed (is usually seen near the apex only)
  35. 35. • Maxillary first molars with two palatal roots were described by Stone & Stroner, Hulsmann, Baratto-Filho et al., and Barbizan et al. • A case with five roots (two MB, one DB, and two palatal roots) and five canals was reported by Barbizan et al.
  36. 36. • Single palatal roots with two separate canals were reported by Thews et al., Stone & Stroner, and Hartwell & Bellizzi. • Palatal roots with a tri-furcated canal were described by Wong and Maggiore et al. • Cases with three separate canals in the mesio- buccal root were reported by Martinez-Berna & Ruiz-Badanelli and Beatty, whereas two canals in the disto-buccal root were found by Martinez- Berna & Ruiz-Badanelli and Bond.
  37. 37. 37 Single-rooted first and second molars commonly showed types I, IV (0.5%) and type III (1%) canal systems, respectively. Buccal roots of two-rooted first molars showed 2 canal systems, type I and type IV, whereas second molars with 2 roots showed wide variations in canal anatomy. The most common canal morphology in the mesiobuccal roots of three-rooted first and second molars was type I (51.8% and 62%, respectively), followed by type IV (38.6% and 50%, respectively). The distobuccal and palatal roots of first and second molars showed predominantly type I canal morphology. Additional canal types were identified in 2.2% and 9.3% of the first and second molars, respectively. Prasanna Neelakantan, Chandana Subbarao, Roshni Ahuja, Chandragiri Venkata Subbarao, James L. Gutmann Cone-Beam Computed Tomography Study of Root and Canal Morphology of Maxillary First and Second Molars in an Indian Population Journal of Endodontics, Volume 36, Issue 10, Pages 1622-1627
  38. 38. Maxillary second molar Average time of eruption, 11 to 13 years; average age of calcification, 14 to 16 years; average length 20 mm. Root curvature (most common to least common): mesiobuccal root—distal, straight; distobuccal root—straight, mesial, distal; Palatal root—straight, buccal.
  39. 39. 39
  40. 40. • Roots and Root Canals: Usually has three roots close together. • All the three roots may fuse together to form a single conical root. • Palatal root is usually straight; buccal curve 37%. • MB root usually curves distally; straight 22%. • Distal root is usually straight, mesial curve 17%. • If buccal roots fuse to form a single root, the tooth then has only 2 canals. Pulp Chamber: •Similar to that of maxillary first molar, except it is narrower mesiodistally. •Roof is more rhomboidal in cross section (because of its smaller size); the floor of the pulp chamber is an obtuse triangle in cross section. •MB and DB canals are more closer and seem to have a common opening.
  41. 41. Variations • Most studies concerning the canal morphology of maxillary second molars reported that the majority of these teeth have three roots. • In a review and radiographic survey of 1200 maxillary second molars, Libfeld & Rotstein reported that 90.6% of these teeth had three roots with three or four canals, • Whereas 6% of the teeth were two-rooted, 3% had a single root, and 0.4% had four roots. • Rotstein(1989) in a review and radiographic survey of 1200 teeth reported a 0.4% incidence of four-rooted maxillary second molars.
  42. 42. • Zmener & Peirano, Fahid & Taintor, and Jafarzadeh et al. described cases with three buccal roots fully separated. • Alani reported a case of bilateral four-rooted maxillary second molars that had two buccal and two palatal roots.
  43. 43. • Vertucci investigated the canal configuration of 100 maxillary second molars and found, in the mesiobuccal root, • One canal in 71% of cases, • Two canals joining in 17% of cases, and • Two separate canals in 12% of cases. • Disto-buccal and palatal roots presented a single canal in 100% of cases. • C-shaped canals are very rare in maxillary second molars.
  44. 44. Mandibular incisors Average time of eruption, 6 to 8 years; average age of calcification, 9 to 10 years; average length: 20.7 mm. Root curvature (most common to least common): straight, distal, labial
  45. 45. 45
  46. 46. • Root and Root Canals: • 1 - 1 (70%). • 1 – 2 (22%), • 2 – 2 (3%). • Root canal is broad Labio-lingually in cervical and middle third, tapers gradually to the apex.
  47. 47. Variations in Mandibular Central and Lateral Incisors • The morphology of mandibular central and lateral incisors is very similar. • Many studies have examined the root canal systems of these single-rooted teeth, confirming that it is not as simple as it may appear to be on standard periapical radiographs.
  48. 48. • Vertucci studied the root canal morphology of 300 extracted mandibular anterior teeth and found two canals in 30% of mandibular central incisors and in 25% of mandibular lateral incisors. • In a study on 1085 extracted mandibular incisors, Miyashita et al. found one single canal in 85% of teeth, two joining canals in 12% of cases, and two independent canals in 3% of the teeth.
  49. 49. • In an investigation on 100 mandibular anterior teeth, Kartal & Yanikoglu identified two new root canal types, which had not been previously identified. • The first configuration was a 2-3-1 type. • The second new configuration was a 1-2-1-3 type. • Although some of the morphological variations may depend on different ethnic backgrounds, two canals should be expected in about one- quarter of mandibular incisors.
  50. 50. 50 Mandibular canine Average time of eruption, 9 to 10 years; average age of calcification, 13 years; average length, 25.6 mm. Root curvature (most common to least common): straight, distal, labial.
  51. 51. 51
  52. 52. • Pulp Chamber: • Resembles Maxillary Canine (smaller in dimensions). • Pulp chamber is narrow mesio-distally. • Labio-lingually, chamber tapers to a point in the incisal third of the crown, wide in the cervical third. • One pulp horn, in cross-section the chamber is ovoid in the cervical third • Root and Root Canals: • Usually one root, 2 roots in 2.3% • Roots are straight (68%), distally (20%), Mesial (1%), labially (7%), 2% S-shaped; when curved distally, the curve is sharper. • 1 – 1 (78%); 2-1 (5%); 1-2-1 (18%); 2-2 (2%).
  53. 53. Variations • Pecora et al. studied the internal anatomy, direction, and number of roots of 830 extracted mandibular canines. • Using a clearing method, the authors found that 98.3% of these teeth had a single root, 92.2% presented with one canal and one foramen, 4.9% had two canals and one foramen, and 1.2% had two canals and two foramina. • The incidence of two rooted canines was low, 1.7%, always with two canals.
  54. 54. 54 Mandibular first premolar Average time of eruption, 10 to 12 years; average age of calcification, 12 to 13 years; average length: 21.6 mm. Root curvature (most common to least common): straight, distal, buccal.
  55. 55. 55
  56. 56. Pulp Chamber: •Mesiodistal width of the pulp chamber in narrow. •Buccolingually ,the pulp chamber is wide, with a prominent buccal pulp horn that extends a well developed buccal cusp. •The crown has a 30 degree lingual tilt. In cross section, the chamber is ovoid, greater diameter bucco- lingually. 56
  57. 57. • Root and Root Canals: • Usually has a short conical root and may divide in the apical third into 2-3 roots. • Root usually straight (48%); distally curved (35%); buccally (2%); lingually (7%) and S or Bayonet shaped (7%). • If one canal, it will be cone shaped and simple in outline. Mesiodistally narrow, buccolingually broad, tapers towards the apical third. • In cross section, cervical and middle thirds are ovoid, apical third is round.
  58. 58. Variations • In a literature review published by Cleghorn et al. approximately 98% of the 6700 teeth analyzed were single-rooted. • The incidence of two roots was 1.8%. • Three roots and four roots were found in 0.2% and 0.1% of the teeth, respectively.
  59. 59. • Studies of the internal canal morphology revealed that a single canal was present in 75.8% of the teeth. • Two or more canals were found in 24.2% of the teeth studied. • A single apical foramen was found in 78.9% of the teeth, whereas 21.1% had two or more apical foramina. • Canal configurations in mandibular first premolars may vary significantly with respect to ethnicity, race, and sex.
  60. 60. • In a study of mandibular first premolars in a Chinese population using the cross-section method, Lu et al. found • A single canal (type I) in 54% of the teeth, • Two canals in 22% of the teeth, • C-shaped canals in 18% of the teeth, and • Circumferential canals (a single canal splitting into three or four canals at the apical third) in 6% of the cases.
  61. 61. • Uncommon but possible morphological anomalies of the mandibular first premolar are • Two canals in two roots, • Three canals in three separate roots, • Three canals in one root, and • A single main canal that splits into three separate canals and apical foramina
  62. 62. 62 Mandibular second premolar Average time of eruption, 11 to 12 years; average age of calcification, 13 to 14 years; Average length: 22.3 mm. Root curvature (most common to least common): straight, distal, buccal.
  63. 63. 63
  64. 64. Pulp Chamber: Similar to that of mandibular first premolar, except that of the lingual horn is more prominent under a well-developed lingual cusp. Roots and Root Canals: Usually has a single root (rarely 2/3 roots). Wider buccolingually than the first premolar. May curve distally (40%); straight (39%); bucally (10%); lingually (3%); S or Bayonet shaped ( 7%).
  65. 65. Variations • Vertucci found that the second premolar had one root canal at the apex in 97.5% of the teeth studied and two canals in only 2.5%. • Mandibular second premolars may have three canals, but the frequency of this configuration is scarce, appearing to range from 0% to 0.4%. • Premolars with three canals were described by El Deeb, Rodig & Hulsmann , and DeMoor & Carlberson.
  66. 66. • Cases with four canals were reported by Bram & Fleisher, Holtzman, and Rhodes. • A case of a mandibular second premolar with five canals was published by Macri & Zmener.
  67. 67. 67 Mandibular first molar Average time of eruption, 6 years; average age of calcification, 9 to 10 years; average length, 21 mm. Root curvature (most common to least common): mesial root—distal, straight; distal root—straight, distal.
  68. 68. 68
  69. 69. Pulp Chamber: The roof of the pulp chamber is often rectangular in shape. The mesial wall is straight, the distal wall round, and the buccal and lingual walls converge to meet the mesial and distal walls to form a rhomboid floor. The roof of the pulp chamber is located in the cervical third of the crown just above the cervix of the tooth.
  70. 70. • Three distinct orifices are present in the pulpal floor: ML, MB and Distal. • The MB orifice is under the MB cusp, the ML orifice is located in a depression formed by the mesial and lingual walls. • Both MB and ML orifices may be close together under the MB cusp. • The Distal orifice, oval in shape, has the widest diameter buccolingually. If found in marked DB or DL direction, one should seek an additional orifice and canal.
  71. 71. • Root and Root canals. • Usually two well differentiated roots, a third root may be found in some cases either distally or mesially (5.3%) • Mesial root curves distally (84%), straight (16%) • Distal root curves is straight (74%), curves to diatal (21%), mesial (5%).
  72. 72. • Three canals are usually present, • Mesial root, 2-2 (41%); 2-1 (28%); 2-1-2 (10%); 1-1 (12%); 1-2 (8%); rarely 3-3. • Distal root , 1-1 (70%); 1-2 (8%); 2-1 (15%); 2-2 (5%); 2-1-2 (2%). • In cross section, all the three canals are ovoid in the cervical and middle thirds and round in the apical third.
  73. 73. Variations • In a Caucasian population, the majority of mandibular first molars are two-rooted, with various canal configurations in both mesial and distal roots. • According to Vertucci’s classification, the mesial root presents with two separate canals at the apex in 59% of teeth, two canals joining with a single apical foramen in 28% of teeth, a single canal in 12% of teeth, and three canals in 1% of teeth.
  74. 74. • In other studies, the frequency of a middle mesial canal in the mesial root of mandibular molars varies between 1% and 7% of teeth. • The three mesial canals can be separate or can join into two and exit with two apical foramina. • Furthermore, some authors reported cases of mesial roots with four canals, although this finding should be considered rare. • When an additional mesial canal is present, it is located between the two main canals and its orifice is often hidden by a dentinal projection of the pulp chamber wall.
  75. 75. • Distal roots of mandibular first molars, in ethnic Europeans, have • One single canal in about 70% of teeth, • Two canals joining into one in 15%, • Two separate canals in 5%, • One canal that splits into two in 8%, and • One canal splitting into two canals that re-join into one at the apical third in 2% of the cases. • Cases with three canals have been reported in the endodontic literature.
  76. 76. • A major variant of the two-rooted morphology in the mandibular first molar is the presence of a supernumerary root located • disto-lingually [radix entomolaris (RE)] or • mesio-buccally [radix paramolaris (RP)]
  77. 77. • The rate of occurrence of this root dysmorphia in Caucasians and Africans is less than 5%, • Whereas in populations with Mongoloid traits (such as the Chinese, Inuit, and Native Americans), RE occurs with a frequency that ranges from 5% to more than 30%. • A buccally located RP is very rare and occurrs with a prevalence of less than 0.5%.
  78. 78. Mandibular second molar Average time of eruption, 11 to 13 years; average age of calcification, 14 to 15 years; average length,19.8 mm. Root curvature (most common to least common): mesial root—distal, straight; distal root—straight, distal, mesial, buccal; single root—straight, distal, bayonet, lingual.
  79. 79. 79
  80. 80. • Root and Root canals: Majority have two roots (71%); 1 root (27%) and 3 roots (2%). • In single rooted, straight (53%); curve distally (26%); lingually (2%); S or Bayonet shape (19%). Pulp Chamber: Smaller than the first molar, root canal orifices are smaller and close together.
  81. 81. • If 2 roots, mesial root usually curves distally (61%); straight (27%); bucally (4%); S or Bayonet shape (6%). • Three root canals are usually present, • Mesial root, 1-1 (27%); 1-2 (9%); 2-2 (26%); 2-1 (30%). • Distal root, 1-1 (92%); 1-2(1%); 2-2 (4%); 2-1 (3%). • In cross section, all 3 root canals are small and ovoid in the cervical and middle thirds and round in the apical thirds.
  82. 82. Variations • In a study on 149 mandibular second molars, Manning found that • 76% of the teeth had two roots, • 22% had one root, and • 2% had three roots.
  83. 83. • In a study on 100 mandibular second molars, for the mesial root, Vertucci reported • a single canal in 27% of the teeth, • two canals joining in 38%, and • two separate canals in 35% of the teeth
  84. 84. • In the distal root, Vertucci found a • single canal in 92% of the teeth, • two canals joining in 3%, and • two separate canals in 5% of the teeth • The presence of three canals in the distal root of a second mandibular molar has been reported by Beatty & Krell.
  85. 85. 85 Types of pulpal floor. M, Mesial side; D, distal side. (From Min Y, Fan B, Cheung G, Gutmann J, Fan M: J Endod 32, 1155, 2006.) C-shaped canal anatomy: one continuous canal from pulp chamber floor to apex.
  86. 86. 86 Three-dimensional classification of C-shaped canal configuration. A, Merging type; B, symmetrical type; C, asymmetrical type. (From Gao Y, Fan B, Cheung G, Gutmann J, Fan M: J Endod 32, 1062, 2006.)
  87. 87. 87
  88. 88. Morphological changes
  89. 89. Invaginations • Dens Invaginatus : • Classified into three types based on severity, from simple to complex. • Type 1 – invagination confined to crown • Type 2 – invagination that extends past the CEJ but not involve periradicular tissues • Type 3 – invagination that extends beyond CEJ and can have second apical foramen. Often surgical and orthograde root canal therapy is necessary to treat this condition.commonly seen in maxillary lateral incisors.
  90. 90. Invaginations
  91. 91. Pulp stones(denticles)
  92. 92. Changes in morphology due to aging
  93. 93. Curved canals
  94. 94. Conclusion • Deviations from normal anatomy of root canal system is rare but should be suspected if visible on radiographs or an abnormal morphology of pulp chamber is seen. • Finding and obturating every extra canal is a challenge that every dentist must master. Access cavity modifications may be required for stress free entry to complex anatomy.
  95. 95. • The clinicians should be attentive to the signs of anatomical variation. • Bleeding from pulp chamber may reveal the presence and location of the extra canals. • Whenever there is an indication of different anatomy, additional periapical X-rays should be exposed at a mesial or distal horizontal angle.
  96. 96. References • Cohen , Pathways of the pulp,10th edition • Ingle , Endodontics 6th edition • Ingle , Endodontics 5th edition

×