My Overview of Management of Edentulous Patient

1. Treatment of the Edentulous
Patient
Krishnan Parthasarathi
omsaustralia@wordpress.com

2. Background
• Edentulism has significant effect on masticatory efficiency and QoL
• Patients treated with Complete Dentures have significantly more bony
resorption of the alveolus than those who have had partial dentures
or over dentures.
From Calwood and Howell ‘88
I. Dentate
II. Immediately post extraction
III. Well rounded ridge of adequate height and
width
IV. Knife Edge, with adequate height but not
width
V. Flat Ridge inadequate height or width
VI. Depressed ridge with loss of basal bone

3. Background II
• Pattern of resorption not consistent
• Basal bone does not change shape often but alveolar bone does
• Ant Mandible: loss of height and width
• Post Mandible: Loss of height mainly
• Anterior maxilla: loss of width 2X height
• Posterior Maxilla: loss of height and width (buccal)

4. MAXILLA - Options
• No Restorations
• Full Denture
• Implant Supported prosthesis
• Implant-Mucosa supported
(overdenture)
• Implant Supported (fixed)

5. • Aesthetics
• Type of Support
• Fixed or Removable
• Fixed options usually ceramic/porcelain based
• Removable Options – implant supported overdentures, implant retained, tissue supported over
dentures.
• Removables methods include bar and clip, magnets, ball attachments, locater
• Amount of Resorption and Inter-arch Space
• Number of Implants
• Decision made on Quality of bone, anticipated force to be placed on restoration, relationship between
residual ridge, and dental arch
• Generally 4-8 for fixed 4-6 for removable
• Implant Distribution
• Round arch 3 implants in pre maxilla v 2 in square / triangular. Do you need to cantilever anterior
teeth?
• Equidistant, and splinting (cross-arch)
• Cost
Considerations I

6. Maxilla Considerations - Aesthetic
• Lip and Facial Support
• Tooth loss, ridge loss
• Emergence of teeth /implants (should be <45degrees to vertical) (lip
movement)
• Teeth may have to be setup anterior to the ridge due to resorption.
• With more resorption, you need more flange
• Facial Profile
• Concave face with upturned nose is most difficult, as bulking out will
worsen the look.

7. Maxilla Aesthetic Considerations II
Smile Line and Lip Length
• Normal is 75% - 100% tooth show
on smiling.
• IF the patient smiles, and you can
see ridge, it’s difficult to manage.
• Incisal edge position
• Need to show 0.2mm show

8. Maxillary overdenture
• 4 implants (bar)
• 6 implants if poor bone, high forces.
• Implants >10mm in length, textured
• Bar, load sharing seems to increase success (but not large studies)
• More maintenance
• No difference in patient satisfaction cf fixed prosthesis?

9. Posterior Maxillary bone – the problem
• You need to have implants with at least 2cm AP Spread
• At least 10mm for distal implant length
• 6 or more implants (Although all-on-four concept exists in maxilla)

10. Solution to the Maxillary Problem
• Graft Options
• Sinus Augmentation
• Onlay Grafting
• Graft less options
• ‘Summers sinus lift’?
• Short Implants
• “Bedrossian solutions 2011’

11. Graft Option - Sinus Augmentation I
• Can be used with immediate placement (if>5mm) or delayed implant
placement (4months post)
• Can be done with immediate loading if torque > 30nM (from all on
four data – Patzelt 2013, Soto-Penazolo 2017)
• Summers lift
• May only give small amount of additional height (? <4mm)
• Perforations may occur
• Early loading may not be as successful
• Lateral Window
• Greater flexibility
• Lefort with Marrow and block graft

12. Graft Option - Sinus Augmentation II
• Options for grafting – Autogenous
bone Allograft (DBx), Xenograft
Allopast(HA, tricalcium phosphate,
Fabbaro 2004)
• All have about equivocal efficacy.
• ? Autogenous graft with rough implants
slightly better survival (94% v 90%)
• Comparing Autogenous Sites
• Intraoral sites (tuberosity, buttress,
chin, ramus, zygoma) lower resorption
(11-14%) cf Illiac graft. Chin Graft best
(Klijn 2010)
• Particulate v block bone equivalent TBV,
but block better histologically
• Studies (Nissan 2011) using block
freeze dried block bone seem to show
equivocal result to autogenous bone.

13. Graft Option - Other 1
• Onlay, Sandwhich (inlay), DO,
• Block Augmentation
• more successful horizontal than vertical (more walls / less pressure?).
• Intramembranous superior to endochondral
• Sandwhich (lefort 1)technique
• difficult to maintain sinus lining, invasive, still need iliac crest harvest, expensive
• Alveolar distraction
• No donor site
• Techinically difficult
• Need 6 -8mm of bone
• Infection, need to over correct, multiple appointments, techinuque sensitive
• Esposito 2009 – Short implants have less failure than vertically augmented ridges,
• but you need enough bone to start,
• goes againgst all-on four principles of long distal implant.
• Need wider implants (?5mm) so you need enough space between implants and ridge width

14. Is Grafting worth it?
• Esposito 2014 shows equivalent results with grafting v short implants
(5mm – 8.5mm).
• Shwartz 2015 – 6mm implants
• Lots of articles out there but bias of mixing mandibular and maxillary short
implants (bone type)
• Also lots of pilots and short follow ups.
• Thoma 2015 attempted a systematic review, but too heterogenous group to
compare – Jury still out, but rising evidence for short implants.
• Esposito 2014 – Type of Implants – Smooth have less peri-implantitis,
but more early loss cf rough implants.

15. Graftless options
• Short Implants,
• All-on-four
• Angled implants
• Zygoma implants
• Quad Zygomas
• Pterygo-maxillary implants

16. Graftless – All-on-four
• All-on-four (Chan Den Clin 2015)
• Based on branemark studies.
Originanlly 4-6 vertical implants
• 10 yr survival of originals approx. 80%
for maxilla (90% for mandible)
• Matteson showed possible with 10mm
height 4mm wide ridge
• Krekmanov started using posterior
tilted implants for increased a-p distr
• Angulation of 30-45 degrees allow 10-
12 teeth per arch

17. Graftless – All-on-4 II
• “Shelf All-on Four”
• Jensen 2010.
• Bony reduction to allow implants to be placed
as a “M”
• Interocclusal distance of 22mm
• Angulation of implants 30 degrees

18. Graftless – Tilted implants
• As predictable as upright implants (patzelt 2013, Soto-penazolo 2017)
• Del Fabro 2012
• No difference in loss, bone loss, loosening of prothetic c.f straight implants
• Typically 25-30 degreesin mandible, and 30-45degrees in maxilla
• Implant failure in first year is 1-25%, failure of OI 28%.
• Maxillary failure > Mandible (RR 2.49)
• ? Overload of distal implant, leading to loss

19. Graftless - Zygoma Implants
Traditionally (Branemark) used in combination with for axial implants in premaxilla.
Success rate is clinically 90%

20. Graftless - Zygoma Implants
• Yates 2014 – Survival rate 86%
• Chrcanovic 2013 (Systematic review)
• 4,556 ZIs in 2,161 patients with 103 failures.
• The 12-year CSR was 95.21%.
• Most failures were detected within the 6-month postsurgical period (when placing
abutments).
• Studies (n = 26) that exclusively evaluated immediate loading showed a statistically lower ZI
failure rate than studies (n = 34) evaluating delayed loading protocols (P = .003).
• Studies (n = 5) evaluating ZIs for the rehabilitation of patients after maxillary resections
presented lower survival rates.
• The probability of presenting postoperative complications with ZIs was as follows: sinusitis,
2.4% (95% confidence interval [CI], 1.8-3.0); soft tissue infection, 2.0% (95% CI, 1.2-2.8);
paresthesia, 1.0% (95% CI, 0.5-1.4); and oroantral fistulas, 0.4% (95% CI, 0.1-0.6). However,
these numbers might be underestimated, because many studies failed to mention the
prevalence of these complications.

21. Edentulous Mandible Options
• No Rehabilitation
• Removable Dentures
• Implant supported prosthesis
• Implant retained prosthesis
• Overdentures
• Graft-less v Graft Techniques
Graft options Graftless
• Horizontal defect
• Particulate
• Block
• split
• Vertical Defect
• Sandwhich
• DO
• Onlay
Short Implants
Angulated implants
Nerve lateralisation

22. Mandibular Overdenture
Advantages Disadvantages
Over Denture Fewer implants – decreased cost
Can have more bulk for improved facial aesthetics
Good access for hygiene
Improved stability with upper complete denture
Easier to modify base
Better tolerated than complete dentures
Implant loss similar to other implant therapies in
the mandible (2.5% pror to loading, 5.6% post
loading)
Higher incidence of complications.
High number of repairs
goodachre 2017 in fonseca

23. Overdenture - How many implants?
• 1 – Is it sufficient? Rocking.
• 2 – can be individual or with bar
• 3 – with bar
• 4 – no difference in outcome cf 2 in general.
• These conditions include the presence of a large V-shaped anterior ridge,
reduced flanges due to high muscle attachments, increased occlusal forces
(dentate maxilla present or parafunctional habits present), atrophic ridges
that require implants of less than 3.5 mm in width or less than 8 mm in
length, and patients with an extreme gag reflex.
• In Mandible no difference bar v no bar (cf maxilla)

24. Mandibular Graft Techniques - Horizontal
• Horizontal Defects
• Add to buccal surface usually
• Want 7-8mm posteriorly (to accommodate 5mm implants)
• Anteriorly atleast 4mm for 3mm implants
• Bicuspid zone atleast 6mm for 4mm implants
• Can use block graft or particulate graft
• Cordaro – 23% loss in horizontal block bone grafts at 6 months
• Esposito 2009 – no dfiferencce between autogenous (chin, bioss). Use of
resorbably v non-resorbably screws prp

25. Mandibular Graft Techniques – Vertical 1
• Posterior Mandible
• Vertical Defects most common and challenging
problem for two reasons: 1) IAN presence, 2) the
common pattern of height loss is vertical
• Block grafts
• 42% resorption at 6 months (cordaro 2002)
• (so if you want 4mm, you need an 8mm graft!).
• Particulate graft
• Resorption May be reduced if use titanium mesh to
reduce resorption, but have have to protect from
exposure and infection for 6 weeks.
• Use implant to pack against and maintain height ( Marx
2002)

26. Mandibular Graft Techniques – Vertical 2
• Alternatives: DO, Sandwich technique, Short Implants, Angled implants, Nerve
lateralisation
• DO seems to allow more height gain + less tension? But more technically demanding, and
demanding of patients. Atleast two surgeries – distraction placement, removal and implant.
• Sandwich/inlay technique- Simion 92. less height gained, also problems with exposure with
soft tissue under tension. Can gain up to 5mm with either technique. This also takes two
surgeries for split alone and third for implant. Esposito 2009
• Short implants seem to have less failures short term than grafting.
• Most of these except for DO and short implants seem to have a common
theme problem – soft tissue envelope deficiency or pressure causing
resorption.
• Nerve lateralization – still need to read about this. BSSO v window?
• Has very high rate of parasthetsia – need to read to confirm number

27. Mandibular graftless techniques
• Short implants, mini implants (still need to read ? Only for tissue
supported)
• Short implants have very high success rates comparable with traditional atleast at
short time points Grant 2009 JOMS,
• Traditional all-on-4
• Good success rate 93.2% for mandible
• All-on-4 shelf:
• flatten ridge, but need atleast 10mm over MN
• Implants need to be atleast 20mm apart
• All-on-4 with tilted implants: “ V4 implant”
• For when there is 5-7mm of arch
• Implants are 30 degrees to sagittal plane.

28. Reminder on all-on-4