a brief discussion on implant treatment options for completely edentulous ridges.

1. Classification and treatment
plan for completely edentulous
patient
12/3/19
Presented by- Shashi kiran
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2. Contents
• Classify available bone
• Classify completely edentulous ridge
• Available prosthetic options
• Treatment planning for edentulous mandible (removable and
fixed)
• Treatment planning for edentulous maxilla (removable and fixed)
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3. Classification of available bone
• In 1985, Misch and Judy established four basic divisions of available bone for implant dentistry
in the edentulous maxilla and mandible, which follow the natural bone resorption phenomena
of each region, and determined a different implant approach to each category.
• These original four divisions of bone were further expanded with two subcategories to
provide an organized approach to implant treatment options for surgery, bone grafting, and
prosthodontics.
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4. Misch and Judy classification
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5. Division A (Abundant Bone) Division B (Barely Sufficient Bone)
Division C (Compromised Bone) Division D (Deficient Bone)
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6. Classification of Completely Edentulous
Arches
• The edentulous jaw is divided into three regions and described according to
the Misch–Judy classification.
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7. • The division of bone in each section of the edentulous arch determines the
classification of the edentulous jaw.
• The term type is used in the completely edentulous classification rather than
class, as in the partially edentulous classification
• Type1
• Type 2
• Type 3
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8. Type 1
• In a type 1 edentulous arch, the division of bone is similar in all three
anatomical segments
• Therefore, four different categories of type 1 edentulous arches are present
• In a type 1, division A ridge, with abundant bone in all three sections, as many
root forms as needed may be inserted (and the locations of implants are not
limited) to support the final prosthesis
• Type 1 div B
• Type 1 div A
• Type 1 div C
• Type 1 div D
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9. • The type 1, division B edentulous ridge presents adequate bone in all three
sections in which to place narrow-diameter root form implants
• The edentulous arches classified as type 1, division D (compromised bone) are
the most challenging to traditional and implant dentistry
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10. Type 2
• In a type 2 completely edentulous arch, the posterior sections of bone are
similar but differ from the anterior segment.
• These edentulous ridges are described in the completely edentulous
classification with two division letters following type 2, with the anterior
segment being listed first because it often determines the overall treatment
plan
• Type 2 div A, B
• Type 2 div A, C
• Type 2 div A, D
etc………
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11. Type 3
• In type 3 edentulous arches, the posterior sections of the maxilla or mandible
differ from each other. This condition is less common than the other two types
and is found more frequently in the maxilla than the mandible
• In type 3 edentulous arches, the posterior sections of the maxilla or mandible
differ from each other. This condition is less common than the other two types
and is found more frequently in the maxilla than the mandible
• Type 3 div A,B,D
• Type 3 div A,B,C
• Type 3 div B,C,D
Etc…….
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12. Available prosthetic options
• Removable prosthesis vs Fixed prosthesis
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13. Prosthetic Options
• In 1989, Misch proposed five prosthetic options for implant dentistry
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14. 14

15. FP1
FP3
FP2
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16. RP4 and RP5
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17. Treatment Plan Sequence
• Because the primary causes of complications in implant dentistry are related
to biomechanics, Misch developed a treatment plan sequence to decrease the
risk of biomechanical overload, consisting of the following steps :
• 1. Prosthesis design
• 2. Patient force factors
• 3. Bone density in the edentulous sites
• 4. Key implant positions
• 5. Implant number
• 6. Implant size
• 7. Available bone in the edentulous sites
• 8. Implant design
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18. The Edentulous Mandible: Treatment Plans
for Implant Overdentures
• Advantages
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19. • Disadvantages
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20. • The greatest available height of bone in an edentulous mandible is located in
the anterior mandible between the mental foraminae. This region also usually
presents optimal density of bone for implant support.
• Therefore, the implant overdenture treatment options presented are
designed for anterior implant placement between the mental foramina
because the prostheses’ movement will be more limited and the available
bone volume and density are more favorable than when implants are inserted
more posterior
Mandibular Implant Site Selection
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21. • The available bone in the anterior mandible (between the mental foramen) is
divided into five equal columns of bone serving as potential implant sites,
labeled A, B, C, D, and E, starting from the patient’s right side
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22. Mandibular Overdenture Treatment
Options
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23. • two implants may be inserted in the B and D positions. The implants remain
independent of each other and are not connected with a superstructure
• Positioning of the implants in the B and D position is a much better prosthetic
option in OD-1 than positioning in the A and E regions
Overdenture Option 1
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24. Overdenture Option 1
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25. • The patient’s primary advantage with treatment option OD-1 is reduced cost. The two implants
are usually the fewest implant number, and no connecting bar reduces the prosthetic
appointments and the laboratory costs
• The disadvantages of the OD-1 prosthesis relate to its relatively poor implant support and
stability compared with any of the other options (which have connecting bars and more
implants) because of the independent nature of the B and D implants
• future bone loss in the edentulous regions of the mandible is not reduced significantly
because only two anterior implants are inserted
• For the restoration to be inserted and function ideally, the two implants should be parallel to
each other perpendicular to the occlusal plane at the same horizontal height (parallel to the
occlusal plane) and equal distance off the midline
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26. Overdenture Option 2
• The anatomic needs and patient desires are similar to the first option, OD-1.
The implants are also positioned in locations B and D, but in this option, they
are splinted together with a superstructure bar without any distal cantilever
• Reduced loading forces are exerted on two anterior implants when splinted
with a bar compared with individual implants.
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27. • Some additional disadvantages of OD-2 treatments compared with
OD-1 are possible tissue hyperplasia under the bar,
• more difficult hygiene under the bar (compared with option 1),
• and a more expensive initial treatment option compared with
option 1 (because a bar and retentive elements are included
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28. Overdenture Option 3
• The third treatment option may be used when the opposing arch is
a denture and the patient has moderate to low anatomic needs.
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29. • Three root form implants are placed in the A, C, and E positions for
the third overdenture treatment option (OD-3).
• A superstructure bar connects the implants but with no distal
cantilever. In addition, the opposing arch should be a denture to
limit the amount of bite force
• The A-C-E implant and bar position is much more stable than the B-
D position for the prosthesis
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30. • The OD-3 treatment option is usually the first option presented to a
patient with minimal complaints who is concerned primarily with
retention and anterior stability of the IOD when cost is a moderate
factor
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31. Overdenture Option 4
• In the fourth mandibular overdenture option (OD-4), four implants are placed
in the A, B, D, and E positions. This is often the minimum number of implants
when the patient has opposing maxillary teeth or C–h anterior bone volume
• These implants usually provide sufficient support to include a distal cantilever
up to 10 mm on each side if the stress factors are low
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32. • The prosthesis is still RP-5 but with the least soft tissue support of
all RP-5 design
• The patient benefits from the four-implant option because of
greater occlusal load support, lateral prosthesis stability, and
improved retention
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33. Overdenture Option 5
• In the OD-5 treatment, five implants are inserted in the A, B, C, D, and E
positions. The superstructure is usually cantilevered distally up to two times
the A-P spread (if almost all of the stress factors are low) and averages 15 mm,
which places it under the first molar area
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34. The OD-5 treatment option
is also indicated when the
patient desires a RP-4 or
fixed restoration, the arch
form is square for a RP-5
prosthesis, or the maxillary
arch has
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35. 35

36. To summarise
• An ideal approach for the overall long-term health of the mandible
is a complete implant–supported prosthesis (RP-4 or fixed
restoration)
• The patient initially may not be able to afford an OD-5 option (with
a RP-4 or fixed prosthetic option). However, an OD-3 may be
converted to an OD-4 after several years and eventually to an OD-5
after several more years
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37. The Completely Edentulous Mandible:
Treatment Plans for Fixed Restorations
37

38. Treatment Option 1: The Brånemark
Approach
• Treatment option 1 places four to six implants between the mental foramina,
and bilateral distal cantilevers replace the mandibular teeth
• As a general rule, when five to six anterior implants are placed in the anterior
mandible between the foramina to support a fixed prosthesis, the cantilever
should not exceed 2 times the A-P spread, with all other stress factors being
low
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39. 39

40. • Treatment option 1 depends greatly on patient force factors; arch form; and
implant number, size, and design.
• As a result, the safest action is to reserve this option for patients with low
force factors, such as an older woman wearing an upper denture with
abundant anterior bone and crown height less than 15 mm, with a tapered or
ovoid mandibular arch, good bone density, and posterior segments of
inadequate height for endosteal implant placement.
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41. Treatment Option 2
• A slight variation of the ad modum Brånemark protocol is to place additional
implants above the mental foramina because the mandible flexes distal to the
foramen
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42. • An implant above one or both foramina presents several advantages.
• First, the number of implants may be increased to as many as seven (which
increases the implant surface area).
• Second, the A-P spread for implant placement is greatly increased (usually by 7
mm) even when the total implant number is five. The more distal implant
position reduces the class 1 lever forces generated from the distal cantilever.
• Third, the length of the cantilever is reduced dramatically because the
distalmost implant is placed one tooth more distal
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43. The key implant positions in
treatment option 2 are the
second premolar positions, the
canine positions, and the central
incisor or midline position. The
two optional implant sites are
the first premolar sites and are
more often indicated when the
patient force factors are greater
than usual.
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44. • A prerequisite for treatment option 2 is the presence of available bone in
height and width over one or both foramina. Because the foramen usually is
located 12 to 14 mm above the inferior border of the mandible, available bone
height is reduced in this location.
• When available, the foramen often requires implants of reduced height
compared with the anterior implants.
• A minimum recommended implant height of 9 mm and a greater diameter or
an enhanced surface area design are recommended to compensate for the
reduced implant length
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45. Treatment Option 3
• The key implant positions for treatment option 3 are the first molar (on one
side only), the bilateral first premolar positions, and the bilateral canine sites.
The secondary implant positions include the second premolar position on the
same side as the molar implant and the central incisor (midline) position
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46. 46

47. • This approach is superior to treatment option 1 or 2 with bilateral cantilevers
because
• (1) the A-P spread is dramatically increased,
• (2) more implants may be used if desired, and
• (3) only one side has a cantilever.
• However, this option requires available bone in at least one posterior region of
the mandible
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48. Treatment Option 4
• This option is selected when force factors are great or the bone density is poor.
This option is also used when the body of the mandible is division C–h
• In treatment option 4, implants are placed in all three segments of the mandible.
Key implant positions for this treatment option include the two first molars, two
first premolars, and two canine sites. Secondary implants may be added in the
second premolars or the incisor (midline) position (or both)
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49. • All implants in the anterior and one posterior side are splinted together for a
nine-unit, fixed prosthesis.
• The other posterior segment is restored independently with an independent
three-unit, fixed prosthesis supported by implants in the first premolar and
first molar region as the key positions
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50. • The primary advantage of this treatment option is the elimination of
cantilevers. As a result, risks of uncemented restorations and occlusal
overload are reduced.
• Another advantage is that the prosthesis has two segments rather than one.
The larger segment (molar to contralateral canine) has an improved
advantage because it has implants in three to four different horizontal planes.
• Because no cantilever is present, weaker cements can be used to install the
prosthesis.
• If the prosthesis requires repair, the affected segment may be removed more
easily because only the segment requiring repair needs to be removed
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51. • Disadvantages for treatment option 4 include the need for abundant bone in
both mandibular posterior regions and the additional costs incurred for one to
four additional implants.
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52. Treatment Option 5
• Another modification for the completely edentulous mandible is to fabricate
three independent prostheses rather than one or two.
• bilateral implants in the first molars, second premolars, first premolars, and
both canine positions.
• These eight implants may also have a secondary implant in the midline.
• The fixed anterior prosthesis usually extends from first premolar to first
premolar (or less often canine to canine). The posterior restorations are two
independent implant prostheses, usually with two units
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53. 53

54. • The advantages of this option are smaller segments for individual restorations
in case one should fracture or become uncemented.
• In addition, if greater mandibular body movement is expected because of
parafunction or a decrease in size of the body of the mandible, the
independent restorations allow the most flexibility and torsion of the
mandible
• The primary disadvantage of option 5 is the greater number of implants
required. In addition, the available bone needs are greatest with this
treatment option
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55. To summarise
• Many completely edentulous patients desire a fixed restoration rather than a
removable prosthesis. Costs for a fixed implant prosthesis often have been a
deterrent but should be more similar to a completely implant-supported
overdenture.
• The most ideal treatments are options 4 or 5 because they lack cantilevers,
and the dentist fabricates two or three separate restorations
• Options 4 and 5 increase overhead costs because more implants are used for
support of the fixed restoration
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56. The Edentulous maxilla- Key Implant
Positions
• 1. Cantilevers on prostheses designed for partially edentulous patients or complete
edentulous maxillae should preferably be eliminated; therefore, the terminal
abutments in the restoration are key positions.
• 2. Three adjacent pontics should not be designed in the prosthesis, especially in the
posterior regions of the mouth.
• 3. When the canine is missing, the canine site is a key position, especially when other
adjacent teeth are missing.
• 4. When the first molar is missing, the first molar site is a key implant position for all
partially edentulous patients and completely edentulous maxilla
• 5. Five sided arch
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57. • 5. Five sided arch
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58. • The first molar implant sites in a completely edentulous maxilla almost always
have been invaded by the maxillary sinus, and most edentulous maxillary
anterior regions are inadequate in width.
• Therefore, to insert more implants in the ideal positions, most maxillary arches
require sinus grafts, and many also require premaxilla reconstruction to ideally
restore the edentulous maxillary arch
• With these concerns in mind, ideally the minimum implant number for most
completely edentulous maxillary fixed or RP-4 prostheses is usually seven in
the ovoid arch form
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59. • The suggested locations for this dentate arch form are at least one central (or
lateral) incisor position, bilateral canine positions, bilateral second premolar
sites, and bilateral distal half of the maxillary first molar sites.
• These seven implants should be splinted together to function as a
biomechanical arch. These implant positions create sufficient space between
each implant to allow for greater implant diameters in the molar regions
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60. • A square dental arch form may use a minimum of six implants: bilateral
canines, bilateral second premolars, and bilateral first molar sites (see Figure
25-29). More moderate force factors or softer bone types may require eight
implants in the edentulous arch
The four pontics between the
canines may counter rule 2 of
key implant positions (no three
adjacent pontics) because
(1) the forces are lowest in the
incisor region and
(2) in a dentate square arch form
in the maxilla, minimal
cantilevers are placed on the
canines
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61. • When force factors are moderate to severe or the dental arch form is tapered,
the minimum implant number should increase to eight implants
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62. 62

63. • When force factors are greater than usual and bone density is poorer,
additional implants should be used in any of the arch forms.
• In the square and ovoid arch form, one additional implant is often positioned
in the premaxilla.
• In addition, for patients with higher force factors and poor bone density, one
additional implant is planned in the distal half of each of the second molar
positions to increase the biomechanical arch form, increase the A-P distance
compared with the first molar site, and add an additional implant
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64. 64

65. • In conclusion, the number of implants used in an edentulous maxilla may
range from six to 10, and the number of implants needed in an edentulous
maxilla is related to arch shape.
• When force factors are moderate to severe or bone density is poor, more
implants should be inserted and in greater diameter to enhance the surface
area of support to the prosthesis.
• The A-P distance should also be increased by adding second molar implant(s)
whenever forces to the premaxilla are greater than usual
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66. • The dentist may use the following guidelines for implant locations in a
completely edentulous maxilla:
1. The bilateral canine position is a key implant position and is planned for 4-
mm-diameter implants.
2. The center of the first premolar is planned 7 to 8 mm distal from the center
of the canine implant (for a 4.0-mmdiameter implant). This is an optional
implant site when parafunction is moderate to severe
3. The center of the second premolar is 7 to 8 mm distal from the first
premolar site (14 mm from the midcanine position) on each side for a 4.0-
mm-diameter implant. This is a key implant position
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67. 4. The distal half of the first molar is 8 to 10 mm distal from the mid second
premolar implant. Ideally, the implant should be 5 to 6 mm in diameter. This is
a key implant position
5. The center of the second molar is 8 to 10 mm distal from the center of the
first molar implant. This position is most important for the edentulous arch
with a tapered dentate arch form, D4 bone types, or severe force factors.
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68. The Edentulous maxilla- implant
overdenture options
• only two treatment options are available for maxillary IODs, five treatment options are available
for the mandibular IOD
• The difference is primarily due to biomechanical disadvantages of the maxilla compared with
the mandible.
• Independent implants are not an option for maxillary IODs because bone quality and force
direction are severely compromised. In addition, the attachment is closer to the tissue, and the
CHS from the attachment is greater, so the prosthesis has more movement. Cantilever bars are
not recommended for the same reasons
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69. Option 1: Maxillary RP-5 Implant
Overdenture
• The first treatment option for a completely edentulous maxilla uses four to six
implants supporting a RP-5 prosthesis, of which three are usually positioned
in the premaxilla.
• Implant number and location are more important than implant size, but the
implants should be at least 9 mm in length and 3.5 mm in body diameter
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70. • An improved number of implants for a RP-5 prosthesis is five. The key implants
are positioned in the bilateral canine regions (guideline 3 of treatment
planning) and at least one central incisor position (guideline 2 of treatment
planning). Other secondary implants may be placed in the first or second
premolar region (five-sided arch of treatment planning)
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71. • Six implants are often indicated for a RP-5 prosthesis when force factors are
greater. The implants are always splinted together with a rigid bar. There is no
distal cantilever, and the bar design should follow the dental arch form but
slightly lingual to the maxillary
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72. Option 2: Maxillary RP-4 Implant
Overdenture
• The second option for a maxillary IOD
is a RP-4 prosthesis with six to 10
implants, which is rigid during
function
• This option is the preferred IOD
design because it maintains greater
bone volume and provides improved
security and confidence to the
patient compared with a denture or
RP-5 restoration.
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73. • Two of the key implant positions for the RP-4
maxillary IOD are in the bilateral canines and
distal half of the first molar positions
(guidelines 3 and 4 in treatment planning)
• Additional posterior implants are located
bilaterally in the premolar position,
preferably the second premolar site.
• In addition, at least one anterior implant
between the canines often is required
(guideline 2 in treatment planning).
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74. • Therefore, six implants is the minimum suggested number for a RP-4
treatment option, and seven implants are used more often.
• When force factors are greater, the next most important sites are the second
molar positions (bilaterally) to increase the A-P spread and improve the
biomechanics of the system.
• A tenth implant may be placed in the premaxilla for a tapered arch form
• The six to 10 implants are splinted together around the arch with a rigid bar
(five-sided arch in treatment planning). Four or more attachments are usually
positioned around the arch
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75. To summarise
• Maxillary IODs may be as predictable as mandibular overdentures
when biomechanical considerations specific to the maxilla are
incorporated in the treatment plan.
• In general, this requires implants in greater numbers and a greater
awareness of prosthetic principles
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76. Thank you
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