Arrangement of artificial teeth for edentulous patients

1. Selection and Arrangement of Teeth
for Complete Dentures
By: Dr. Rohan Bhoil

2. Contents
• Introduction
• Review of literature
• Selection of anterior teeth
• Selection of Posterior teeth
• Arrangement of teeth
• Conclusion

3. Introduction
• After casts are mounted & occlusal scheme
determined.
• Maintenance of vertical dimension.
• Anterior teeth – primarily aesthetics.
• Posterior teeth – for mastication.
• Harmony.

4. Why selection and arrangement
deserve special attention ?

5. • Absence of periodontium.
• Single unit on an unyielding base.
• Necessity of bilateral balance.
• Consequences of malocclusion.
• Bearing of non vertical forces.
• First molar & second premolar area.
• Proprioception.
• Incising with natural teeth.

6. Review of Literature
• Berry’s Biometric Ratio Method [1906]
– Inverted CI resembles face form
– Tooth size 1/16 face width & 1/20 face length
• Clap’s Tabular Dimension Table Method [1910]
– Tooth size based on six anterior teeth
– Enabled to specify mold
• Cigrande [1913]
– Outline form of fingernail - Outline form of Central
incisor.

7. • Pound E. (1951) - dentures should be
designed according to the principle of nature.
• French A. (1951) - teeth should be arranged
according to the face form, arch form, width
of mouth and ridge relation.
• Frush & Fisher (1955 – 59) - Sex, Personality
and Age of the patient.

8. • Martone A. L. (1964) - loss of the teeth & their
supporting structures produce radical changes
in facial appearances.
• Curtis T. & Shaw E. (1987) - the esthetic
results require more than the size, color,
position and arrangement of complete
denture teeth.
• Golden proportion - by Levin

9. • Preston (1993)

10. • Ward (2000) - Recurring Esthetic Dental (RED)
proportion based on the different heights of
the maxillary anterior teeth.
• However in a study: To evaluate the validity of
Recurring Esthetic Dental proportion in
natural dentition, J Conserv Dent. 2011 Jul-
Sep; 14(3): 314–317., authors Shetty etal,
found that RED proportion was not seen in
natural dentition.

11. Methods Used to Select Artificial Anterior
Teeth for the Edentulous Patient: A Historical
Overview – Selten etal, Int J Prosthodont
1999:12:51
Concluded that to date, no universally
reliable method of determining tooth form
has been found. The Williams classification
(1914) is the most universally accepted
method of determining anterior tooth form.

12. Assessment of Dental Appearance Following
Changes in Incisor Angulation
Wolfart etal, Int J Prosthodont 2004;17:150–154.
• They evaluated the assessment of attractiveness of
standardized changes in incisor angulation of
different tooth arrangements and found that tooth
arrangements showing central incisors with ideal
axes are more attractive, than angulation of one or
both central incisors.
And slight changes in the angulation of one or
both lateral incisors do not influence attractiveness
negatively.

13. • Varjao etal, in their study on Intercommissural
width as a guide for selection of anterior
maxillary teeth ( Int J Prosthodont, 2005;
18;513-515)
– Found that a weak correlation exists between the
corners of mouth and distal of canines and hence use
of corners of mouth for selection of artificial teeth is
generally inaccurate.

14. • Jaffar Abduo, in a systematic review (Int J
Prosthodont 2013;26;26-33) on occlusal
schemes for complete dentures has
concluded that primarily as per patient
acceptance, posterior tooth arrangement in
conventional bilateral balanced occlusion and
lingualized bilaterally balanced occlusion, are
preferable to flat teeth arranged in
monoplane occlusion.

15. 15
Anterior tooth selection
• Size
• Form
• Shade
• Material

16. Size of Anterior Teeth
• Size of Face & Head
– Bizygomatic width / 3.3 – maxillary anteriors
– Bizygomatic width / 16 - maxillary central
– Length of face / 16 – maxillary central
– 10:1 ratio of cranial circumference to upper
anterior teeth.

17. Anatomical Landmarks
• Mark corners of mouth on wax occlusal rims.
• Extension of parallel lines from lateral surface
of ala of nose onto maxillary occlusal rim.
• A line perpendicular to midline of palate
through distal border of incisive papilla.

18. Maxillomandibular Relations -Mandibular
anteriors : class II & III arches.
Contour of residual ridges - teeth placed to follow
contour and size selected according to this position.
Vertical distance between ridges.
Lips – selection of length of maxillary anteriors.

19. High Lip Line
• Highest point of upper lip
when smiling
• Cervical necks lie at or
above this line
• If shorter teeth are
selected, esthetics
compromised

20. • Nose
– Distance between tips of canine is same as width
of base of nose
• Philtrum
– Width of upper centrals, approximates the width
of philtrum

21. Pre – Extraction Records
• Facial Photographs
• Diagnostic Casts
• Radiographs
• Teeth of Close Relatives
• Extracted teeth.

22. Form of Anterior Teeth
• Pre-extraction records
• Form and Contour of Face

23. Leon William’s Classification
• Square
• Square – Tapering
• Tapering
• Ovoid

24. Dentogenic Concept
• Frush & Fisher (1957), Dynesthetics
• Sex factor
– Feminine : softness
– Masculine : boldness & hardness
• Personality factor
– Vigorous type, medium type & delicate type
• Age factor
– Incisal edge, erosion, diastema, stippling of
interdental papilla.

26. Shade selection for Anterior Teeth

27. Shade Selection
• Along side of nose – basic hue, value &
chroma.
• Under lips – only incisal edge exposed – effect
of colour with mouth relaxed.
• Under lips – only cervical end covered – smile.
• Use of Squint test.

28. 28
Posterior tooth selection
• Size
• Form
• Shade

29. Size of Posterior Teeth
• Buccolingual Width
– Sufficient to act as a table to
hold food.
– Less than width of natural
teeth.
– Not to encroach on tongue
space and buccal corridor.
– Limits forces directed to ridge.

30. • Mesiodistal Width
– Edentulous space available.
– Placed as far as possible posteriorly.
– Not over beginning of ascending area of ramus
and retromolar pad.

31. • Occlusogingival Height
– Determined by available inter ridge space, occlusal
plane and height of anterior teeth.
– Teeth with largest possible vertical length that can
be used without grinding are preferred for
aesthetics.

32. Form of Posterior Teeth
• Anatomic Teeth
– Cusp teeth.
– Simulate occlusal surface.
– Varying degrees of inclinations (10°, 20°, 30°, 40°)
– Standard is 33°
– Cusp incline < 33°, is termed semi-anatomic teeth.
– Advantages.
– Disadvantages.
10
°
20
°
30
°

33. Non- Anatomic Teeth
• Cuspless, Monoplane or Zero degree teeth.
• Offer less resistance to horizontal forces
– Bruxism
– Poor residual ridges
– Uncoordinated muscular movements
– Mal relationship of jaws –class II & III
Disadvantages
Shearing efficiency
Poor aesthetics
Lateral & protrusive balance not possible.

34. 34
Shade Of Posterior Teeth
• Harmonize with the shade of
the anterior teeth.
• Bulk influences the shade of
teeth
– select a slightly lighter shade
for the premolars

35. Selection of Tooth Material
• Resin
– Composite Resin
– Acrylic Resin
• Monolithic
• Cross – linked
• IPN linked
• Porcelain
– When aesthetics are paramount
– Adequate interarch space is available.

36. Resin & Porcelain Teeth
• Wear potential
• Grinding & adjusting
• Bonding to denture base
• Abrasion of opposing dentition
• Colour stability
• Impact sound
• Rebasing
• Impact resistance.

37. Posterior Tooth Forms – Historical
Development
• Anatomic teeth
– Trubyte teeth (1914) by
Gysi
– Channel tooth (1927) by
Sears
– Metal insert in resin
(1942) by Vincent
– Crossblades (1961) by
Sosin

38. • Non-anatomic teeth
– Inverted cusp tooth (1929) by Hall- sharp
concenteric ridges around cup like depressions.
– True-kusp (1929) by Meyerson – buccal lingual
ridges with sluiceways between them.
– Chopping block (1934) by Nelson
– Non-lock (1939) by Swenson
– Vitallium Occlusal (1946) by Hardy

39. Teeth Arrangement
• Anatomical landmarks
• Ridge relation
• Balanced occlusion
• Neutral zone

40. Anatomical landmarks
• Residual ridge
– Position in relation to ridge due
to resorptive pattern.
• Arch form
– Square, tapering & ovoid arch
forms

41. • Retromolar pad
– Too low a occlusal plane causes tongue biting and
too high a occlusal plane can cause instability and
strain.

42. • Parotid Duct
– Maxillary first molar
• Rugae
– Labial surface of canine
10.5mm
• Incisive papilla
– Midline
– Central incisor
– Perpendicular line

43. Teeth Arrangement for Class I Ridge
Relation
• Wax rim contours aid selection and setting:
– Occlusal vertical dimension
– Angulation of facial rims affects lip support
– Overjet
• Place reference marks on the occlusion rims to
aid in tooth selection and placement.

44. 44
Orientation Of Occlusal Plane
Occlusal plane
Upper rim
• Anteriorly - parallel to inter pupillary line
• Posteriorly - parallel to Camper's line
Lower rim
• Anteriorly – lower lip
• Posteriorly - Half to two/third retromolar pad.

47. Ideal Arrangement Of Teeth
• Anterior teeth

48. 48
Central Incisor
• Long axis
– parallel to the long axis of the patient face.
• The midline of the dental arch
– the centre of face
• Labial contour
– blend with the contour of face.
• Rotation on long axis
– varies depending on arch form

49. 49
Maxillary lateral incisor
• Set at angle of 50 to the perpendicular
• Incisal edge is about 1 mm short of the
horizontal plane
• Labial surface is inside at the cervical end
• Distal half of rotated slight lingually

50. 50
Canine
• Cervical end is more prominent labially
• Canine is the turning point of arch
– mesial half is harmony with ant teeth
– distal half harmony with post teeth (PM)
• Tip of cusp is in contact with the occlusal
plane

53. The lower anterior teeth

54. 54
Central Incisor
• Long axis
– Parallel to vertical viewed from front
• Slopes labially when viewed from side
• Incisal edge 1-2mm above the horizontal
plane

55. 55
Lateral Incisor
• Long axis
– parallel to the vertical viewed from front.
• Slope labially

56. 56
Canine
• Long axis
- slightly lean towards midline
when viewed from front
– slightly lingually when viewed
from side
• Cusp is slightly above 0.2 mm
above the horizontal plane

57. • Canine key of occlusion
– The distal incline of the lower canine should align
with the mesial incline of the upper canine.
57

59. Limits To Placing Anterior Teeth
• The medio lateral and antero posterior
position of maxillary ant teeth
– limited by phonetics and esthetics

60. Phonetics
• Long teeth F sounds like V
• S sounds – two tongue positions
– Palate
– Lower anterior teeth

61. Upper posterior teeth arrangement

62. 62
First Premolar
• long axis
– parallel to vertical axis when
view from labial side.
• Palatal cusp is 0.2 mm sort
of its buccal cusp from
horizontal plane.
Due consideration is given in
esthetics in female

63. 63
2nd Premolar
• Both buccal and palatal cusps touches the
occlusal plane

64. 64
The First Molar
• Long axis
– Long axis slopes bucally
when viewed distally
from side.
• Mesiolingual cusp

65. • Molar key of occlusion
– The mesiobuccal cusp of the maxillary permanent
molars should coincide with the mesiobuccal
groove of the mandibular permanent molar
65

66. 66
2nd molar
• More inclined than 1st molar
• Cusps above horizontal plane

67. Maxillary teeth set, checked on a
flat plane

68. Lower Posterior Teeth

69. 69
First Premolar
Long axis
– parallel to the vertical axis
• lingual cusp is below the horizontal plane
• buccal cusp about 02 mm above occlusal
plane

70. 70
Second Premolar
• Long axis
–parallel to vertical axis
• Both cusp are about 02 mm above the
horizontal plane

71. 71
The First Molar
• Long axis
– leans lingually when viewed from the front
– mesially when viewed from the side
• All the cusps are at higher level above the horizontal
plane than those of second premolar

72. 72
2nd molar
• More inclined than 1st molar
• Cusps above horizontal plane

74. Teeth arrangement checked in
patients mouth

75. Setup for class II & III cases

76. Set up in class II jaw relations
• In this setting, the flattened lingual cusp of
upper premolars occludes with the flattened
buccal cusp of lower premolars and a large
buccal horizontal overlap occurs in the bicuspid
area.
• Upper molars are set with their lingual cusp in
the modified central cusp of the lower teeth.
• Posteriors should have a centric occlusion with
stable non-deflective stops.

77. Setup in Class III relation
• If ridges are edge to edge, then anterior teeth are
also placed edge to edge.
• In cases of extreme protrusion,
– negative or reverse horizontal overlap is used,
– a larger lower tooth mold can be used,
– Interchange of upper and lower teeth
– First premolar may be eliminated from upper arch
– Transverse ridges of upper posteriors are grinded
away to eliminate mesiodistal interlocking.

78. Balanced Occlusion
• After centric balance is achieved, teeth
arrangement is modified to achieve eccentric
balance.
• At least a semi-adjustable articulator is
required.
• For lateral balance, buccal cusps of posterior
teeth should contact on working side and on
non-working side, contact should occur
between mandibular buccal & maxillary
palatal cusps.

79. • To develop balanced occlusion in Protrusion
– With the anterior teeth edge to edge, contacts
should simultaneously be established in the
posterior teeth.
– Factors affecting balance
• Condylar inclination cannot be altered.
• Incisal guidance can be manipulated limitedly.
• Cuspal inclination is determined by selection of teeth.
• So mainly, the anterio-posterior Curve of Spee
influences protrusive balance.
• Thus, steeper the condylar inclination, steeper should
be the compensating curve with low cuspal inclination,
to achieve protrusive balance, while maintaining the
centric contact.

80. Setup in neutral zone technique
• Neutral zone is recorded.
• Impression is indexed.
• Teeth arrangement is guided by index.
• Posterior teeth may require to be trimmed
lingually so that they fit into index space.
• Polished surfaces of denture are also
contoured to replicate record.

81. 81
Characterization
• Subtle chips ,stains make teeth look more
natural
• Highest quality of art is to conceal art

82. Conclusion
• Selection and Arrangement of teeth is an art
based upon biomechanical factors, governing
the ultimate success of dentures.

83. References
• Zarb - Bolender : Prosthodontic treatment for
edentulous patients. Twelfth edition, 2004.
• Sharry J.J. : Complete denture prosthodontics, 1968.
• Rahn and Heartwell : Textbook of complete denture,
4th edition, 1993.
• Boucher. C.O: Prosthodontic treatment for edentulous
patients. Tenth edition
• Dental Clinics of North America : Esthetic Dentistry,
April 1989

84. Thank you !!!