Assessment and planning of the edentulous patient

Question 1

What is the recommended standard tx for the edentulous patient?
-US?
-UK?
(2)

Answer 1

US:
-two-implant supported overdentures for mandible
UK: complete dentures but this is no longer most appropriate choice

Question 2

Current indications for progressing to implant-retained overdentures on the NHS (2)

Answer 2

Instability despite well-adapted set of dentures
Denture intolerance
-gag reflex (reduce palatal coverage)
-ongoing pain with well-adapted dentures

Question 3

Clinical assessment of the edentulous patient for implants (4)

Answer 3

Denture
-in place
-outside mouth
Mandible
-residual ridge
-mental nerve
Denture vs mandible
Radiographic assessment

Question 4

Assessment of denture intraorally (4)

Answer 4

Ridge adaptation
Margins
Occlusal stability
Overclosure
-acceptable fit?

Question 5

Importance of assessing denture thickness (4)

Answer 5

Min 8.5mm
Thickness for overlying denture
Thickness for locator housing
Thickness for supragingival component of locator abutment

Question 6

Minimum space requirements for
-bar attachment
-ball attachment
-locator attachment
(3)

Answer 6

Bar: 15mm
Ball: 10mm
Locator: 8.5mm

Question 7

Assessment of residual ridge (3)

Answer 7

Buccolingual width
Variation in crestal contour
Mentalis insertions and “exostoses”

Question 8

Buccolingual assessment of ridge width (1)

Answer 8

If narrower than width of implant, may be problematic

Question 9

Variation in crestal contour (2)

Answer 9

May limit available space for denture components

May need to be addressed surgically

Question 10

Potential effect of mentalis insertion on the severely resorbed mandible (1)

Answer 10

Avoid placement too far labial

Question 11

Position of mental foraminae (2)

Answer 11

Influences how far distal implants may be able to be placed

Superficial mental foramen may make incision crestally a risk of nerve injury

Question 12

Mental nerve - local anatomy (3)

Answer 12

Between lower 4 & 5 in general population
Is apical to lower 5 in chinese subpopulations
Anterior limb if IDN curves back before exits mental foramen

Question 13

Positioning of implants for overdentures is different to crown and bridgework (2)

Answer 13

Centre of denture fitting area - if anything, more lingual better
Near-parallel placement - otherwise wear of locators/ limits male units

Question 14

Direct attachment pick-up (2)

Answer 14

Separator painted on fitting surface

Cold cure acrylic painted into reliefs