This document discusses definitive obturators for edentulous patients who have undergone maxillectomy surgery. It covers prognostic factors, impression techniques, records, occlusion, and delivery considerations. Key points include outlining the degree of movement, available support surfaces, and means of retention as important prognostic factors. Impressions should capture undercuts and extensions into the defect. Records are made using customized trays with minimal blockout. Neutrocentric occlusion is preferred. Delivery involves checking for tissue displacement and perfecting the occlusion.

1. Definitive Obturators: Edentulous Patients
John Beumer III, DDS,MS
Distinguished professor emeritus
UCLA School of Dentistry
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2. Definitive Obturators: Edentulous
Patients
v Objectives
v Prognostic factors
v Impression methods
v Maxillo-mandibular records
v Occlusion
v Delivery

3. Definitive Obuturators - Edentulous
Maxillectomy Patients
Objectives:
u Restore the partition between the oral and
nasal cavities so as to enable normal speech
and swallowing
u Restore palatal contours
u Replace needed dentition and restore the
occlusion
u Provide retention, stability, support for the
complete denture obturator prosthesis

4. Prognostic factors – Edentulous Patients
Degree of movement. The more movement during
function the poorer the prosthodontic prognosis. The
degree of movement is dependent upon:
l Amount and contour of the remaining palate
l Availability of undercuts in the defect
l Availability of support areas within and peripheral to the
defect

5. Prognostic factors – Edentulous Patients
Axis of rotation for this defect is located along the medial
palatal margin of the defect. The portion of the obturator at
right angles and most distant from this axis will exhibit the
greatest degree of motion.

6. Prognostic factors – Edentulous Patients
Degree of Movement
In a posterior defect, when more of the premaxillary
segment is retained, the axis of rotation moves posteriorly.

7. Prognostic factors – Edentulous Patients
Degree of Movement
In anterior defects, the axis of rotation of the prosthesis
is located along posterior margin of the defect. The
anterior extension of the prosthesis will exhibit the
greatest potential for movement.

8. Prognostic factors – Edentulous Patients
Degree of Movement
• With smaller defects, and particularly when a tuberosity
segment is retained, considerably less movement of the
prosthesis will be observed.
• Main issue in this patient will be retention

9. Prognostic factors – Edentulous Patients
Denture bearing surfaces available for Support
l Residual palatal shelf
l Alveolar ridge contours
l Oral side of the soft palate
l Access to a skin lined lateral third of the
orbital floor
l Skin lined base of the skull
l Presence of a remaining tuberosity on
the defect side
The more support available
the better the prognosis

10. Prognostic factors – Edentulous Patients
Means of Retention
Defect side
Lateral wall of the defect
Undercut just superior to the
skin graft mucosal junction
Nasal side of the soft palate
Nasal aperture
Normal side
Denture adhesive
Osseointegrated implants
The better the retention the better the prognosis.

11. Prognostic factors – Edentulous Patients
Stability is affected by:
l Alveolar ridge contours
l Lateral wall of the defect
(if skin lined)
l Medial wall of the defect
(if lined with palatal mucosa)
l Use of osseointegrated implants
The better the stability the better the prognosis.

12. Prognostic factors – Edentulous Patients
Static vs dynamic defects
v If the posterior margin of the defect
does not extend beyond the
junction of the hard and soft palate,
the defect will be relatively static -
Static defect i.e. it will not change dramatically
its shape during speech or
swallowing or movement of the
mandible.
v The prognosis for restoration of
static defects is better than the
prognosis for restoration of
dynamic defects
Dynamic defect

13. Prognostic factors
Residual palatal structures
l How much palatal shelf remains? The more the
better the prognosis.
l Is the residual palatal shelf parallel to the
occlusal plane. The more parallel to the plane
the better the prognosis.
Good prognosis l Is there a residual tuberosity on the defect side?
Presence of a tuberosity improves the
prognosis.
l What is the height and contour of the residual
alveolar process? Good alveolar ridge contours
improves the prognosis.
Poor prognosis
Poor prognosis Good prognosis

14. Prognostic factors
Quality of the defect
v Stability-Is the lateral wall of the defect
lined with skin? Is the resected portion of
the palatal bone covered with palatal
mucosa or a skin graft?
v Support-Is the lateral third of the orbital
floor lined with skin? Can the obturator
be extended superiorly to engage this
area? Can the base of the skull be
effectively engaged?
v Retention-How divergent is the lateral wall
of the defect? Is there a significant
undercut just superior to the skin graft
mucosal junction?
The more “yes”
All these
answers the better
defects are the prognosis
favorable.

15. Prognostic factors
Quality of the defect
All four patients shown presented with poor quality defects.
None are lined with skin, resulting in unfavorable contours and
poor quality lining epithelium.

16. Prognostic factors
Neuromuscular control
The successful patient is able to
control the complete denture-
obturator prosthesis, the mandibular
denture and the bolus simultaneously.
Few patients are able to manage these multiple tasks and
will require the placement of osseointegrated implants.

17. Impressions
Preliminary Impressions
Key areas to record
v Residual palatal structures
v Lateral wall of the defect
v Oral side of the soft palate
It is useful to inject impression material into key areas of the
defect with a disposable syringe prior to seating the loaded tray.

18. Impressions
Master impressions
l Custom tray fabrication
• Block out undesirable undercuts
• Medial
• Anterior and posterior
• Flow a thin layer of wax over the
lateral wall of the defect
• Extend tray one cm onto the soft
palate on the defect side
• Extend tray up the full height of the
lateral wall and onto the
posterior wall of the defect
Do not block out the lateral wall undercut.

19. Master impressions
Retention
Ø Posterior-lateral wall of the defect superior
to the skin graft mucosal junction
Ø Nasal side of the soft palate
Support
Ø Residual palatal structures
Ø Base of the skull
Ø Lateral portion of the floor of the orbit
Stability
Ø Residual palatal structures
Ø Lateral wall of the defect

20. Master impressions-Extension into the defect
Extension up the full
height of the lateral
wall of the defect
facilitates retention.
Extension up the
medial wall of the
defect is limited by
the amount of
palatal mucosa
and the need for
normal nasal air
flow.

21. Master impressions
Rentention-Secondary areas
l Nasal side of the soft palate
Nasal aperture

22. Master impressions
Above the level of the soft palate
Master impression trays
Note the extension onto the soft palate on
the defect side
The tray extends up the full height of the
lateral wall of the defect
Note the minimal medial wall extension

23. Master impressions
l Border molding- Low fusing compounds are
recommended because they provide more working time.
Take care to avoid displacement of the tissues Begin
by molding the unresected side. The extension up the
medial wall is minimal. Excessive height in this area
interferes with nasal air flow and offers no advantage in
the anterior portion of the defect (oval).
Proceed to the defect side.
Mold the anterior two thirds of
the lateral wall of the defect
extending the impression up its
full height. Contours below the
skin graft mucosal junction
(line) are dictated by lip
contours, contours above by
cheek contours.

24. Border molding
Develop the contours of the posterior one third of the defect. Take particular
care in developing the extensions associated with the skin graft mucosal
junction. Avoid overextension posteriorly by bringing the mandible forward
and laterally during border molding. If the lateral portion of the orbital floor
or base of the skull is lined with skin attempt to extend the impression into
these areas.
Note the prominent undercut just above the skin graft mucosal
junction in the posterior lateral portion of the defect.

25. Master impressions
Border molding
In this patient the defect extended posteriorly all the way to
pharyngeal wall. Note the imprint made by the medial side
of the mandible in the lateral wall of the impression (arrows).

26. Border molding
l Combined hard – soft palate defect

27. Master impressions
Cut back- Prior to completing the impression,
approximately .5 mm of compound is removed
from the surface.
Before making the master impression the
tissues in the defect must be thoroughly
cleaned so that mucous accumulations
and mucous crusts are removed.

28. Master impressions
Wash materials
l Polysulfide
l Recommended
l Thermoplastic waxes
l Generally not indicated for edentulous patients
because of lack of occlusal stops
l They are, however, useful in making reline
impressions in edentulous patients (because
presence of occlusal stops)

29. Master impressions
Polysulfide is preferred. Its viscosity and flow
make it ideal for large maxillary defects.
Before inserting the coated border molded tray,
it is advisable to inject polysulfide material onto
the lateral wall of the defect (arrows) and into
appropriate undercuts.
If the undercut is severe it is useful to inject medium
body rubber base into the undercut and coat the
rest of the tray with light body.

30. Master impressions
Defects extending into the
velopharyneal area*
l These areas may be modified with a
thermoplastic wax
Soft palate at rest
Soft palate elevated
*In most patients these areas
need to be refined at delivery.

31. Master impressions
Boxing the master impression and pouring the cast
l The master impression is boxed in the usual manner

32. Centric Relation Records
Record bases and wax rims
v Minimal blockout should be used for the lateral
wall of the defect. If excessive block out is
employed the record base will be very unstable
making it difficult to make accurate records.

33. Centric Relation Records
Record bases and wax rims
Minimal blockout should
be used for the lateral
wall of the defect. If
excessive block out is
employed the record
base will be very
unstable making it
difficult to make accurate
records.

34. Conventional Record bases
l Used when there is reasonable stability and support, either from
the defect or from the residual palatal structures.
Both these patients
had sufficient stability
and support to use
conventional record
bases.
Making accurate and reproducible
records is very difficult in these
patients. The clinician must maintain
control of both record bases
simultaneously while making the
centric relation record.

35. Record bases
l Processed are considered:
l When stability and support are deficient
l In large defects with little palatal shelf and poor
alveolar ridge contours
This patient had a large defect and little palatal shelf
remained. A processed record base was used to make
centric relation records. The teeth were added later with
autopolymerizing acrylic resin.

36. Vertical dimension of occlusion (VDO)
l Usual methods for determining the proper VDO are used
l VDO should only be reduced when patient exhibits severe
trismus in order to permit easy access of the bolus
Occlusal vertical dimension

37. Centric relation records
v Begins with a face bow record and mounting the maxillary cast
v Articulators modified to accept large maxillary casts are used
v Records are made in the customary fashion using record bases
and wax rims

38. Articulators
a b
a: Articulator capable of receiving large
maxillary cast.
b: Articulator modified to accept large
maxillary casts.

39. Occlusal schemes
Neutrocentric is preferred
l All teeth on the plane of occlusion. The maxillary lateral
incisors may be lifted up off the plane to enhance esthetics.
Lip plumpers may be added in
selected patients with facial
nerve weakness
In this patient, a radical neck was performed on the side opposite the
maxillectomy and the marginal mandibular nerve was resected- hence
the lip plumper was added to the mandibular denture.

40. Try-in of Trial Denture and Obturator
Verify:
Ø Centric relation record
Ø Vertical dimension of occlusion
Ø Esthetic display

41. Processing
l Heat cured methyl methacrylate
l Obturator portion should be hollow to reduce weight
l Silicones are avoided because of their susceptibility to
deterioration in the presence of candida albicans
Important characteristics and landmarks:
a) Imprint of skin graft mucosal junction
b) Imprint of the medial side of the ramus of the
mandible
c) Extension onto the residual soft palate (1 cm)
d) Extension up the lateral wall of the defect

42. Delivery Steps
v Pressure indicating paste - Used to delineate areas
of tissue displacement on the unresected side
v Disclosing wax – Used for checking peripheral
extensions and monitoring tissue displacement in
the defect
v Clinical remount – Used to perfect the occlusion

43. Identifying Areas of Tissue Displacement
Pressure indicating paste
l Used primarily on the oral mucosa and on the
unresected side
l Spray silicone releasing agent onto the PIP in patients
with radiation induced xerostomia

44. Identifying areas of tissue displacement
Disclosing wax
v Used in skin lined defects for patients who are xerostomic
(PIP tends to stick to skin lined surfaces in such patients)
The wax is placed into
a disposable syringe,
immersed in a water
bath to soften the wax
and then applied to the
surface of the
obturator. The
restoration needs to
remain in place for 1-2
minutes before
removal and
inspection.

45. Checking peripheral extensions
v Imprint of the ramus
v Peripheral extensions on the unresected side
Periphery wax applied Pattern after removal Note displacement of
tissues anteriorly
Tissue displacement in the
posterior lateral area
A good pattern

46. Clinical Remount
l Perfect the occlusion with a new centric relation
record
We favor the neutrocentric scheme of
occlusion using no anatomic posterior
denture teeth and with no vertical overlap of
the anterior teeth.

47. Completed obturator with ideal contours
Lateral wall extension Vertical extension- posterior
vertically for retention medial portion of the defect to
minimize leakage (oval) Maximum
and stability
extensions for
stability
Proper adaptation to the
residual palatal shelf for
Engagement of the support Imprint of the
lateral third of the medial side of
orbital floor for the ramus
support (oval)
Proper extension (5-10mm)
onto the oral side of the soft
palate to prevent leakage
(arrows)

48. Completed obturator with ideal contours
Lateral wall
extension
vertically for
retention
and stability
Coverage of skin lined skull
base enhances support

49. Delivery and Followup
Note the dramatic changes in soft
tissue contour following insertion of the
complete denture and obturator. This
patient was also fitted with an orbital
prosthesis.

50. Edentulous patients with partial palatectomy defects
l Retention may be difficult to achieve because
of limited access to the defect
In this patient, the obturator portion was processed in silicone in
order engage bony undercuts and to facilitate retention. This
silicone liner must be replaced yearly however.

51. Edentulous patients with partial palatectomy defects
Defects extending into the middle third the of soft palate
l Challenge – Retention and leakage of fluids into the nasal
passage during swallowing during palatal elevation.
Soft palate at rest Soft palate elevated
Osseointegrated implants can be
used to provide retention To minimize leakage, the
obturator should extend
onto the nasal side of the
residual soft palate (arrow).

52. Edentulous patients with partial palatectomy defects
Defects extending into the middle third the of soft palate
Challenge – Retention and leakage of fluids into the
nasal passage during swallowing during palatal
elevation.
v Relatively small partial maxillectomy defect. It is difficult
to engage such defects and implants are recommended
to enhance retention.
v Nasal side of soft palate engaged to enhance seal