The permanent maxillary central incisor


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The permanent maxillary central incisor

  1. 1. The Permanent Maxillary Central Incisor
  2. 2. Permanent Maxillary Central Incisors   Central incisors are four in numbers centered on the maxilla, one on each side of the median line
  3. 3.  Maxillary and mandibular central incisor are the only neighboring teeth in the dental arches with mesial surfaces in contact
  4. 4.     Central incisor is longer than Lateral Incisor These supplement each other in function ,similar anatomically For sheering or cutting Incisal ridges or edges rather than cusps
  5. 5.  Incisal edge- portion of the crown which make up the complete incisal portion  Edge- implies an angle formed by the merging of two flat surfaces  Incisal edge-is formed by the junction of the linguoincisal surface and labial
  6. 6. Central Incisor       Is the widest of any anterior teeth mesiodistally Symmetrical and regularly formed Nearly straight incisal edge Cervical line with curvature toward the root Mesial side with D straight outline D M Distal side more FACIAL VIEWS curved Right maxillary M Right maxillary
  7. 7.     Mesial incisal angle is relatively sharp Distal incisal angle rounded Labial surface of crown is usually convex at the cervical 3rd/flat at the middle 3rd and incisal portions Presence of mamelons for newly erupted M teeth D F M D MESIAL FACIAL VIEWS Right maxillary lateral incisor L Right maxillary central incisor Right maxillary central incisor
  8. 8.  Presence of developmental lines on the labial surface which divides into 3 parts noticeable at the middle portion
  9. 9. Lingual surface of Maxillary Central Incisor    the surface is more irregular Concave at the middle and incisal portion and bordered by the mesial and distal marginal ridges,the lingual portion of incisal ridge and cingulum Gives a “scoop like” form of the crown
  10. 10. Detailed description of the Max. CI from all aspects Distal outline of the crown  More convex than the mesial outline  Crest of the curvature is higher toward the cervical line  Rounded distoincisal angle 
  11. 11. Incisal outline Regular and straight in a mesiodistal direction  Tends to curve downward toward the center of the crown outlining making the crown longer at the center than at the two mesial and distal angle 
  12. 12. Cervical outline      It follows a semicircular direction with the curvature root wise Root Cone-shape, blunt apex with regular outline both mesially and distally Root is usually 2-3 mm. longer than the crown Line drawn through the center of the root and crown of the maxillary central incisor tends to parallel the mesial outline of the crown and root
  13. 13. Lingual aspect      Has convexities and concavities Presence of cingulum Mesially and distallytconfluent with the cingulum are marginal ridges With shallow cavity the lingual fossae Linguoincisal edge is raised somewhat at the level of the marginal ridges mesially and distally
  14. 14.   Usually there are developmental grooves extending from the cingulum into the lingual fossae The crown and root taper lingually, making the crown calibration of the two labial line angles greater than the two lingual line angles, making the lingual portion of the root narrwer than the labial portion
  15. 15. Cross section of the Root   At the cervix is triangular with rounded angles one side of the triangle is labial with the mesial and distal sides pointing lingually The mesial side of this triangle is a larger than the distal side
  16. 16. Mesial Aspect The crown is wedge-shaped,or triangular, with the base of the triangle at the cervix and the apex at the incisal ridge  A line drawn at the center of the crown and root will bisect the apex and also the incisal ridge of the crown 
  17. 17.  Incisal ridge of the crown is in line with the center of the root which is the fundamental characteristics of the maxillary Central and Lateral incisor
  18. 18.  Labially and lingually immediately coronal to the cervical line are the crest of the curvature of these surfaces, they are the one that gives the crown its greatest labiolingual measurement of about .5 mm extension before continuing the outline to the incisal edge
  19. 19. Labial outline  Is slightly convex from the crest of the curvature to the incisal edge
  20. 20. Lingual outline  Convex from the crest of the curvature to the cingulum, concave at the mesial marginal ridge, and become slightly convex again at the incisal ridge and incisal edge.
  21. 21.  Cervical line outlining the CEJ is directed incisally  Cervical curvarture is greater on the mesial surface than any surface or any other tooth in the mouth.  Root cone shape with blunt rounded apex
  22. 22. Distal aspect  Because of the slope of the labial surface distolingually, more of that surface is seen from the distal aspect, creating an illusion of greater thickness  Curvature at the cervical line outlining the CEJ is less in extent on the distal than on the mesial surface. Most teeth show this characteristic.
  23. 23. Incisal Aspect  Labial aspect is relatively broad and flat in comparison with the lingual surface  Cervical portion labially is convex  Lingual portion The outline tapers lingually towards the cingulum Cingulum-makes up the cervical portion of the lingual surface
  24. 24.  The crown conforms to a triangular outline similar to the cross section at the cervix  Incisal ridge may be sees clearly and a differentiation between the incisal ridge and incisal edge with its slope towards the lingual is easily distuinguished
  25. 25.  The mesiolabial and distolabial line angles are prominent in this aspect compare to the mesiolingual and distolingual line angle which is made up of mesial and distal marginal ridges.
  26. 26. Maxillary Lateral Incisors
  27. 27. It supplements the central incisor in function  Crown bears a close resemblance to the central incisor  It is smaller in all dimensions except root length 
  28. 28. This tooth differs from central incisor in:  Variation in development more than any other tooth in the mouth except the 3rd molar Ex. Peg shaped laterals Pointed tubercle on the cingulum deep developmental grooves extending from the cingulum to the roots, twisted roots and distorted crowns 
  29. 29. Detailed Description of the Maxillary Lateral Incisor Labial aspect Although it is similar in appearance with Central Incisor, it has more curvature. Rounded incisal ridge and rounded incisal angles mesially and distally Crown is smaller in all dimensions Its proportions corresponds to those of the central incisor 
  30. 30. Lingual aspect      Cingulum is prominent Linguoincisal ridge is well developed The lingual fossa is more concave and circumscribed than the central incisor Tooth tapers toward the lingual Not uncommon to find a deep developmental groove at the side of the cingulum,usually on the distal side, which may extend up on the root form part or all of its length.
  31. 31. Mesial aspect       Similar to that of a small central incisor except that the root appears longer Crown is shorter.the root is relatively longer Curvature of the cervical line is in the direction of incisal ridge The root appears as a tapered cone from this aspect with a bluntly rounded apical end The labial outline of the root from this aspect is straight A line drawn through the center of the root tends to bisect the incisal ridge of the crown
  32. 32. Distal aspect    The width of the crown distally appears thicker than it does on the mesial aspect from marginal ridge to labial face. The curvature of the cervical line is usually a millimeter or so less in depth than on the mesial side. Not uncommon to find a developmental groove distally on the crown extending on the root for part or all its length
  33. 33. Incisal aspect      Sometimes resembles that of the central incisor or it may resembles that of a small canine From this aspect bit resemble a central incisor except in size Cingulum and incisal ridge may be large Labiolingual dimension greater than usual in comparison with the mesiodistal dimension All maxillary lateral incisors exhibit more convexity labially and lingually from the incisal aspect than maxillary central incisors
  34. 34. Permanent Mandibular Central Incisor
  35. 35. Permanent Mandibular Incisors are centered in the mandible  Mesial surface of each one contact with the other  Right and left mandibular lateral or second incisors are distal to the central incisors 
  36. 36. The Permanent Mandibular incisors Similar in form and have smooth crown surfaces  Mamelons are worn off soon after eruption  contact areas are near the incisal ridges mesially and distally  Anatomic form differs entirely from the maxillary incisors 
  37. 37. contact areas are near the incisal ridges mesially and distally  Anatomic form differs entirely from the maxillary incisors  Outlines and surfaces are regular and symmetrical 
  38. 38. Mandibular Central Incisor     Smallest tooth in the dental arches Crown is more than half the mesiodistal diameter of the maxillary central incisor Labiolingual diameter is only 1 mm or less the single root is very narrow mesiodistally and corresponds to the narrowness of the crown,although the root and crown are wide labiolingually
  39. 39. Detailed Description of the Mandibular Central Incisor from all aspects Labial aspect  Is regular tapering evenly from the relatively sharp mesial and distal incisal angles to the apical portion of the root  Incisal ridge of the crown is straight and is approximately a right angle to the long axis of the tooth
  40. 40. Labial aspect of Mandibular central incisor the mesial and distal outlines of the crown make a straight drop downward from the incisal angles to the contact areas which are incisal to the junction of incisal and middle thirds of the crown.
  41. 41.   The mesial and distal outline sides of the crown taper evenly from the contact areas to the narrow cervix The mesial and distal root outlines are straight with the mesial and distal outlines of the crown down to the apical portion
  42. 42.    The apical third of the root terminates in a small pointed taper curving distally,sometimes straight Labial surface is smooth which flattenedat the incisal third,more convex middle third Labial surface of the root is regular and convex
  43. 43. Lingual aspect of mandibular central incisor Smooth,slight concavity at incisal third  Marginal ridges are more prominent near the incisal edges  Becomes flat and then convex from incisal third to the cervical third 
  44. 44. Mesial aspect of mandibular central incisor   Curvature labially and lingually above the cervical line <found on maxillary incisors Outline of the labial face of the crown is straight above the cervical curvature sloping rapidly from the crest ofcurvature to the incisal ridge
  45. 45.  The lingual outline of the crown is a straight line inclined labially for a short distance above the smooth convexity of the cingulum: the straight outline joins a concave line at the middle third of the crown, which extends upward to join the rounded outline of a narrow incisal ridge
  46. 46. The incisal ridge is rounded or worn flat and its center is usually lingual to the center of the root  The root outline from the mesial aspect are straight with the crown outline from the cervical line 
  47. 47.  The mesial surface of the crown is convex and smooth at the incisal third and becomes broader and flatter at the middle third cervical to the contact area.
  48. 48. Distal aspect    The cervical line representing the cej curves incisally about 1 mm less than on the mesial is similar that of the mesial surface The developmental depression on the root surface with a deeper and more welldefined developmental groove at the center
  49. 49. Incisal aspect Bilateral symmetry  Mesial half is almost identical with the distal half  Incisal edge at right angles to a line bisecting the crown labiolingually 
  50. 50. Incisal aspect The labial surface of the crown is wider mesiodistally than the lingual surface.  The crown is wider labially than lingually at the cervical third 
  51. 51. Mandibular Lateral Incisor
  52. 52. Mandibular lateral incisor  The 2nd mandibular tooth from the median line  It resembles the mandibular central incisor  Somewhat larger (compare measurements)  operate as teamwork with the central incisor therefore functional form is related
  53. 53. Description of mandibular lateral incisor  Labial aspect and distal aspect show added fraction of approximately 1 mm of crown diameter mesiodistally added to the distal half.
  54. 54. Mandibular lateral incisor  Mesial   and distal aspect Mesial side is often longer than distal side.causing the incisal ridge, which is straight, to slope downward in a distal direction Distal contact area is more toward the cervical 3rd than the mesial contact area
  55. 55.    Crown of mandibular lateral incisor is somewhat longer than that of the central incisor The root maybe considerbly longer Root form is similar to that of the central incisor.
  56. 56. Incisal aspect   Provides a feature that can usually serve to identify this tooth. Incisal edge is not approximately at right angles to a line bisecting the crown and root labiolingually as was found observing the central incisor
  57. 57. Incisal aspect  The edge follows the curvature of the mandibular arch, giving the crown of the mandibular lateral incisor the appearance of being twisted slightly on on its root base
  58. 58.  It is interesting to note that the labiolingual root axes of mandibular central and lateral incisors remain almost parallel in the alveolar process,eventhoug h the incisal ridges are not directly in line.
  59. 59. The Permanent Canines Maxillary and Mandibular
  60. 60. Maxillary and Mandibular canine      Bear a close resemblance to each other and functions are closely related Four canines are placed at the corners of the mouth The third tooth from the midline The longest teeth in the mouth Middle labial lobes have been highly developed incisally into strong well –formed cusps crowns and roots are markedly convex on most surfaces
  61. 61.  Most stable teeth in the mouth because of labiolingual thickness of crown and root  The positions and forms of these teeth and their anchorage in the bone along with the bone ridge over the labial portions called the  Help to form a foundation that ensures normal facial epression at the “corners of the mouth
  62. 62.  In function canines support the incisors and premolars
  63. 63. Maxillary Canine    Outline of labial or lingual aspects is a series of curves except for the angle made by the tip of the cusp. Mesial half of the crown makes contact with the lateral incisor The distal half contacts the first premolar
  64. 64. From the labial aspect    The mesial half of the crown resembles a portion of an incisor,distal half resembles a portion of premolar The labiolingual measurement of the crown is about 1 mm greater than maxillary central incisor The mesiodistal measurement is approximately 1 mm less
  65. 65.    The cingulum shows greater development than central incisor Root is the longest Root is thick labiolingually with developmental depressions mesially and distally that help to furnish the secure anchorage this tooth has in the maxilla
  66. 66. Detailed Description of the Maxillary Canine from All aspects Labial aspect   Crown and root narrower mesiodistally than those of the maxillary central incisor Cervical line is convex with the convexity toward the root
  67. 67. Mesial aspect  Convex outline from the cervix to the center of the mesial contact are or the crown may exhibit a slight concavity above the contact area from the labial aspect. The center of the contact area mesially is approximately at the junction of the middle and incisal thirds of the crown
  68. 68. Distal aspect   Usually concave between the cervical line and the distal contact area Distal contact area usually at the center of the crown.
  69. 69. The cusp has a mesial and distal slope , the mesial slope being the shorter of the two.  Both slopes show a tendency toward concavity before wear has taken place 
  70. 70.  The labial surface of the crown is smooth with no developmental lines except shallow depressions mesially and distally dividing the three labial lobes
  71. 71. The middle labial lobe shows much greater development than the other lobes  This produces a ridge on the labial surface of the crown. 
  72. 72.   A line drawn over the crest of this ridge from the cervical line to the tip of the cusp,is a curved one inclined mesially at its center. All areas mesial to the contrat of this ridge exhibit convexity ecept for insignificant developmental lines in the enamel
  73. 73.    The root of the maxillary canine appears slender from the labial aspect when compared with the bulk of the crown It is conical in form with a bluntly pointed apex The labial surface of the root is smooth and convex at all points
  74. 74. Lingual aspect     The crown and root are narrower lingually than labially Cervical line differs somewhat from the curvature found labially. The cervical line shows a more even curvature The line maybe straight for a short interval at this point
  75. 75.   Cingulum is large in some instances is pointed like a small cusp Definite ridges are found on the lingual surface of the crown below the cingulum and between strongly dveloped marginal ridges
  76. 76.    Occasionally a welldeveloped lingual ridge is seen which is confluent with the cusp tip. This extends to a point near the cingulum There may be shallow concavities between this ridge and the marginal ridges. When these concavities are present they are called mesial and distal lingual fossae
  77. 77.  The lingual portion of the root of the maxillary canine is narrower than the labial portion
  78. 78. Mesial aspect   Present the outline of the functional form of an anterior tooth Outline of the crown is wedge shape ,the greatest measurement being at the cervical third and the wedge point represented by the tip of the cusp
  79. 79.  The entire labial outline from the mesial aspect exhibits more convexity from the cervical line to the cusp tip than the maxillary central incisor does from cervix to incisal edge
  80. 80.  The lingual outline of the crown represented by convex line describing the cingulum,which convexity straightens out as the middle third is reached,becoming convex again in the incisal third
  81. 81.  The cervical line curves toward the cusp on the average ,approx. 2.5 mm (cemento enamel junction)
  82. 82. Lingual aspect The outline of the root is conical,with a tapered or bluntly pointed apex.  The root may curve labially toward the apical third 
  83. 83.  The labial outline of the root may be almost perpendicular with most of the taper appearing on the lingual side
  84. 84.  the mesial surface of the canine crown presents convexities at all points except for a small circumscribed area above the contact area,where the surface is concave and flat between that area and the cervical line
  85. 85.   The mesial surface of the root appears broad with a shallow developmental depression for part of the root length .Developmental depressions on the heavy roots help to anchor the teeth in the alveoli and help to prevent rotation and displacement
  86. 86. Distal Aspect  1. 2. Shows somewhat the same form as the mesial aspect with the following variations: Cervical line exhibit less curvature toward the cuspid ridge The distal marginal ridge is heavier and more irregular in outline
  87. 87. 3. The surface displays more concavity usually above the contact area 4. The developmental depression on the distal side of the root is more pronounced.
  88. 88. Incisal Aspect Emphasizes the proportion of this tooth mesiodistally and labiolingually.  The labiolingual dimension is greater than the mesiodistal 
  89. 89. The ridge of the middle labial lobe is very noticeable labially from the incisal aspect  It attains its greatest convexity at the cervical third of the crown lingually 
  90. 90.   The cingulum development makes up the cervical third of the crown lingually The outline of the cingulum maybe described by a shorter arc than the one labially from this aspect
  91. 91.  A line bisecting the cusp and cusp ridges drawn in the mesiodistal direction is almost always straight and bisects the short arcs representative of the mesial and distal contact areas
  92. 92.  The incisal aspect of most canines max. or mand. May be outlined in many cases by a series of arcs.
  93. 93. The Mandibular Canine
  94. 94. Mandibular canine is narrower mesiodistally than the maxillary canine  The root maybe as long s the max. caninebut usually shorter 
  95. 95.   The lingual surface of the crown is smoother with less cingulum development and less bulk to the marginal ridges The lingual portion of this crown resembles the form of the lingual surfaces of the mandibular lateral incisors
  96. 96.   The cusp of the mandibular canine is not as well developed as that of the maxillary canine,and the cusp ridges are thinner labiolingually A variation in the form of the mandibular canine is bifurcated roots.
  97. 97. Detailed Description of the Mandibular canine in all aspects   Labial Aspect The mesiodistal dimensions of the mandibular canine are less than those of the maxillary canine.
  98. 98. Essential Differences between mandibular and maxillary canines viewed from the labial aspect :     Crowns of mand. Canine appear longer Mesial outline is nearly straight with the mesial outline of the root Mesial contact area being near the mesioincisal angle Distal contact area is more toward the incisal than that of the maxillary canine.