1. Prosthodontic management
of Mandibular Defects

2. Contents
• Introduction
• Challenge
• Classification of mandibular defects
• Complications
• Factors affecting treatment of mandibulectomy
patients
• Relating surgical and prosthetic considerations in
mandibulectomy patients
• Treatment plan
• Management of mandibular deviation
• Implant supported prosthesis
• Conclusion
• References

3. Introduction

4. • Mandible is a single bone that creates
• Peripheral boundaries of the floor of
mouth
• Facial form (Lower third of face)
• Speech
• Swallowing
• Mastication
• Respiration
• Disruption of the mandible has the
potential to disrupt any of these

5. Rehabilitation of mandibulectomy
patients should therefore consider both
form and function .
Thomas
Taylor

6. Surgical resection of tumor often
includes a partial mandibular
resection, a partial glossectomy, a
partial resection of the floor of the
mouth, and a radical neck dissection.
The extent of surgery and the effects of
radiation therapy and chemotherapy
determine the amount of
rehabilitation needed by a given
patient.

7. Oral reconstruction of the patient who
has a partially resected mandible is
one the most challenging procedures
confronting the maxillofacial

8. Classification of mandibular
defects

9. Mandibular Defects
Developmental Acquired
(Mandibular
prognathism/ Pathology
Trauma
retrognathism) (tumors)
(Fractures)
Surgical Mandibulectomy
Gunning splints

10. Acc to etiology - Laney(1979)
1. Acquired:
- Marginal
- Segmental
a) Anterior body
b) Lateral to
midline
- Body only
- Ramus
- Body with
disarticulation

11. 2. Congenital
- Incomplete formation
- Incomplete ossification
e.g.) hypoplasia,
mandibulofacial
dysostosis,etc
3. Developmental
as a result of postnatal insults
e.g.) trauma during birth,
surgery, etc

12. Acc to amount of resection -
Laney• Continuity defect
(marginal resection)
- Inferior border and its
continuity preserved
- No deviation
- Less facial disfigurement
- Occlusion rarely changed
- Can be :- anterior defect
posterior defect
• Discontinuity defect
(segmental resection)
- Complete segment of mandible from
alveolar crest to inferior border
removed
- Mandible deviates to resected side
- Marked facial disfigurement
- Occlusion altered
- Can be :- lateral discontinuity defect
midline discontinuity

13. Acc to Cantor and Curtis (1971)
Class 1
Radical alveolectomy with preservation of mandibular
continuity

14. TISSUES RESECTED
- Portion of alveolar process and body of
mandible
- Lingual and buccal sulcus mucosa
- Portion of base of tongue and
mylohyoid muscle
- Lingual and inferior alveolar nerves
- Sublingual and Sub maxillary
salivary glands
- Sometimes anterior part of digastric
muscle
FEATURES
1. Least debilitating.
2. Can raise the floor of the mouth causing reduction in
tongue mobility.
3. Ability to shape and control the tongue may be lost
due to loss of some intrinsic muscles.

15. Class 2 :
Lateral resection of mandible distal to
cuspid

16. TISSUE RESECTED
- condyle, ramus and body of mandible distal to cuspid
- mylohyoid, hypoglossal,ant belly of digastric,
internal
pterygoid,masseter,external pterygoid,
pharangoglossal
& palatoglossal muscles, most of intrinsic
muscles of
tongue.
- hypoglossal , lingual and inferior alv nerves
- adjacent buccal and lingual mucosa
FEATURES
1 Speech, swallowing, saliva control, manipulation of food impaired.
2. Facial disfigurement apparent
3. Disarticulation and loss of muscles of mastication will hampered
mandibular movements
4. Taste ,sensory and motor losses more extensive as compared to
class 1

17. Class 3
Lateral resection of the mandible to
midline

18. TISSUE RESECTED
all those described in class 2 in addition to the
anterior portion of the mandible,
geniohyoid,
genioglossus, remaining portion of
mylohyoid
muscle with lingual and buccal mucosa.
FEATURES
1. Restricted tongue mobility due to loss of tip of tongue and
genioglossus muscle
2. Speech, swallowing,saliva control and manipulation of food
severely restricted.
3. Facial disfigurement is worse due to loss of anterior part of
mandible
4. Disarticulation and reduction in amount of basal bone
reduce prosthodontic prognosis.

19. Class 4
Lateral bone graft & surgical
reconstruction

20. • Lateral bone and split thickness skin or
pedicle graft can be performed on patients
who have had:
- radical alveolectomies
- resection of mandible distal
to cuspid
with or without
disarticulation.
• Three types of bone grafts are possible
1. Mandibular augmentation procedures.
2. Bone graft that connect a residual
condyle with the larger mandibular
fragment.

21. Class 5
Anterior bone graft &surgical
reconstruction

22. TISSUE RESECTED
- anterior portion of the mandible
- large bilateral portions of mylohyoid,
geniohyoid
genioglossus and anterior digastric muscles
- bilateral lingual and inferior alv nerves
- bilateral submaxillary and sublingual salivary
glands
- mucosa of lower lip
- anterior floor of mouth
- ventral surface of tongue
The mucosa retained in the labial and buccal regions is sutured
to the
residual stump of the tongue and a krischner wire is often
positioned to
maintain the mandibular fragments .

23. Class 6
It is similar to a class V patient, but
the continuity of the mandible has
not been restored surgically. Because
each lateral fragment moves
independently, the prognosis for a
removable prosthesis is poor and
fabrication is not recommended

24. Complicatio
ns

25. With only one half or two thirds of the
mandible remaining, stability, support
and retention of the mandibular denture
are compromised.
Due to radiation therapy either prior to or
after surgery, the oral mucosa is
atrophic and fragile, predisposing to
soft tissue irritation and ulceration.
The reduction in saliva output, and the
thick mucinous nature of the saliva that
remains after therapeutic levels
radiation, impairs retention and

26. The angular pathway of mandibular
closure induces lateral forces upon the
dentures, which dislodge them.
The deviation of the mandible creates
abnormal jaw relationships. The
abnormal profile and position of the
mandible in relation to the maxilla
may prevent ideal placement of the
denture teeth over their supporting
structures.
The impairment of motor and/or
sensory control of the tongue, lip,
and cheek impairs the ability of the

27. Factors affecting
treatment of
mandibulectomy patients

28. Location & Extent of Mandibular
Defect
Marginal alveolectomy
-Least debilitating
-Main problems – loss of vertical ridge
height and vestibular depth
-Vertical discrepancy is most important
when prosthesis supported by dental
implants is considered.

29. Marginal defects have better prognosis
than discontinuity defects.
The farther anterior the defect, the more
disfiguring and functionally
debilitating it is likely to be.
Reason: Loss of key muscle
attachments(genioglossus and
geniohyoid) located in anterior
mandible that control tongue
function and mobility.

30. • Defects of the symphyseal region are
most debilitating and difficult to
treat.
• Greatest facial disfigurement.
• Surgical reconstruction necessary or
at least segmental stabilization
before prosthodontic treatment can be
initiated.

31. Mandibulectomy defects in the molar
region
-well suited for surgical reconstruction
compared to anterior defects.
-If muscle attachments are intact – Good
prognosis
-Near normal appearance and function is
achievable.

32. 2. Presence of remaining natural
teeth/pre-existing implants
Patients after mandibulectomy present with few or
no
remaining natural teeth.
-Pts with greatest risk of sq cell carcinoma are
heavy
users of tobacco and alcohol and lack good oral
hygiene.
-Strong relationship between tobacco & periodontal
disease
-Teeth are usually extracted prior to radiotherapy to
prevent complications such as osteoradionecrosis.
Greater the number of teeth ,better the prognosis.

33. Remaining natural teeth in
linear relationship are unlikely
to provide adequate abutments
for prosthesis than teeth arranged
in two dimensions

34. A maxillary complete denture will
function well for a mandibulectomy
patient against a reconstructed
mandibular dentitionExceptions Collapse of residual proximal
mandibular stump against the posterior
maxillary alveolus prohibiting adequate
denture flange extension.
When a guide flange prosthesis is planned
for treatment of mandibular deviation .
Pressure from Guide flange can dislodge the

35. 3.Degree of post mandibulectomy
rotation and deviation
Mandible deviates towards the defect and rotation
of mandibular occlusal plane inferiorly.

36. • During mandibular closure, mandible
rotates around occlusal contacts on
un-resected side, and remaining teeth
on resected side drop further out of
occlusion. This movement is called
FRONTAL PLANE ROTATION.

37. • Deviation: Due to
• Primarily due to loss of tissue involved in
surgical resection.
Rotation: Due to
- Pull of the suprahyoid muscles on the residual
fragment
causing inferior displacement and rotation
around the
fulcrum of the remaining condyle.
- Gravity. Loss of anchorage of elevator muscles.
Sequelae
• Facial disfigurement
• Loss of occlusal contact

38. • Prosthodontic prognosis in such patients can
be improved by early post resection physical
therapy to reposition the mandibular
fragment to a more normal position and to
minimize scar formation that will make
deviation more severe.
• Should be carried out as early as possible.
• After 6-8 weeks post operatively it will not
be as beneficial.
• Can be in the form of
1.Physical therapy carried out by the
patient himself

39. 5.Available mouth
opening
Trismus –due to surgical trauma
Physical therapy should be started
immediately.
Scar tissue formation will further reduce
mouth
opening.
Simple test to check mouth opening: Insert a
stock
mandibular impression tray in the mouth.If
this cannot

40. 6.Functional limitation of
tongue
- Frequently the surgical wound is closed by
suturing
the remaining tissues of the floor of the mouth
or
tongue to the remaining buccal tissues.

41. This compromises: - Speech
- Swallowing
- Mastication
- Control of food bolus
- Ability to control removable
prosthesis
- Lingual vestibuloplasty and skin or mucosal
grafting can
be used to improve tongue mobility
Evaluation of tongue mobility
- In patients whom anterior resection has been done,
ability to lick the lips when the artificial prosthesis

42. In such cases consideration is given to lowering the
anterior
occlusal plane or arranging the teeth slightly
lingually.
• Speech therapy
• Loss of innervation will compromise tongue function and
prognosis of prosthodontic rehabilitation.
If lingual nerve is sacrificed during resection, the tongue on
the
defect side will permanently remain without any feeling.
Loss of sensory capability:- Affects speech
Mastication
Prosthesis control
Loss of sensory innervation of the buccal mucosa(long

43. 7.Compromise of vestibular
extensions
 Vestibular depth is critical for stability and
peripheral
seal
It is also critical when mandibular continuity is
restored with bone grafting and implants are
considered.

44. 8.Skin grafting
• Skin grafts are used for surgical reconstruction
either as lining for the surface of resected soft tissue
or as part of skin and connective tissue grafts such
as pedicle flaps, free flaps etc.
Advantages
1. Effective load bearing tissue.
2. Can withstand pressure and chafing from
prosthesis.
3. Protects underlying bone and connective tissue
well due to
rapid turnover of keratin producing cells.
Disadvantages
1. No sensory innervations.

45. 9.Radiation therapy
• Careful treatment planning is
required for patients with radiation
therapy
• Irradiated tissue is fragile ,sensitive
to manipulation, dessicated,slow to
heal, prone to infection and at risk of
osteoradionecrosis

46. 10. Altered anatomic relationships
following
restoration of mandibular continuity
 Reconstruction of anterior defects
Most difficult situation for grafting and frequently
results in a
graft that is deficient anteriorly.
- Results in a severe Class 2 like situation.
The prosthodontic difficulties seen in rehabilitating such
a patient
are:-
- Inability to provide proper lip support.
- Speech problems associated with mandibular
dentition
placed too far lingually.
- Inability to control food bolus due to lack of
motor

47. - Excessive display of mandibular teeth due to patients
inability
to maintain normal lip posture.
- Difficulty gaining adequate space for prosthesis
placement
without encroaching on function of tongue.
- Misalignment of remaining un resected mandibular
fragments
and resultant relationship between maxillary and
mandibular
teeth.
 Reconstruction of posterior defects
- More predictable from prosthodontic point of view as
compared
to anterior defects.
- The mediolateral positon of the graft is frequently seen

48. 11. Previous experience with
removable prosthesis
Indicator of how successful
rehabilitation will be, particularly
edentulous patients

49. Relating surgical considerations to
prosthodontic treatment
Marginal mandibulectomy
Soft tissues are mainly used to reconstruct
marginal
mandibulectomies
They may be: - Skin graft
- Local flap
- Pedicle flap
- Micro vascular free flaps (MVFF)
Skin grafts are ideal for prosthetic reconstruction.
However when soft tissue bulk is required or
recipient bed is
previously irradiated micro vascular free flaps are

50. Discontinuity defects
Previously soft tissue local flaps(mainly the residual
tongue sutured to the border of the defect) and
pedicle flaps (pectoralis muscle) were used.
MVFF have revolutionized the treatment of
discontinuity defects.
Micro vascularized bone is mainly obtained from:
1.Fibula- most common
2.Iliac crest
Soft tissue MVFF are obtained from
1.Forearm
2.Rectus muscle

51. Mandibular mal position after bony
reconstructionMay be due to:
1. Minimal proximal mandible on the surgical side to attach the
bone graft.
2. Mandibular segments are not stabilized and maintained in
their
pre-operative relation to each other during grafting
procedures.
3. Delayed reconstruction may not be able to overcome scar
tissue
formation completely.
4. The bone grafts used i.e the fibula and the iliac crest graft
have
some inherent problem.
(Lacks height compared to the residual mandible)

52. PROSTHODONTIC
REHABLITATION

53. All basic principles of complete
denture construction must be
considered and modified because
of the unusual anatomic and
functional situation.

54. TREATMENT PLAN
 Exercise regimen
 Reconstruction
 Definitive Guidance Prosthesis.

55. Treatment options
• Conventional complete denture
• Cast partial denture /sectional
denture prosthesis.
• Implant retained and supported
overlay denture

56. Impressions
Maximum extension and tissue
coverage should be recorded with the
preliminary impression
Irreversible hydrocolloid is used with
an altered/sectional stock tray.
Conventional border molding and
Master impression is used to achieve
better peripheral seal.

57. Primary impression

58. Shifman and Lepley(1982)
Neutral zone or denture space concept
for marginal mandibulectomy
patients.
They supported this by quoting
Fish(1933) and Brill(1965)

59. Secondary impression
with border molding

60. Processed bases
• Necessary due to loss of supporting bone ,unusual
intra-oral contours, gross mal position of occlusal
contacts.
• Allow the determination of the relationship of the
final prosthesis periphery and the buccal or
lingual tooth position.
• Recording maxillo-mandibular relationship with
processed bases allow the clinician to evaluate
retention and stability proir to adding wax rims
or dentition.

61. • Significant loss of alveolar bone as well as rotation
and deviation of the mandible postoperatively make it
necessary for the record bases to be as stable as
possible during maxillo mandibular records.
• Extension beyond the periphery of the prosthesis may
be
required to support the lip. To add stability to the
prosthesis, occlusal contact may need to be
significantly buccal or
lingual to normal anatomic landmarks that usually
denote the occlusal table.
• Pts who have implant retained prosthesis should have
retentive elements incorporated in the processed

62. Jaw relation
• Centric relation does not exist in
partially mandibulectomy patients
with discontinuity defects because
there is only one condyle to guide the
mandible.
• Interestingly they do have
proprioception for a repeatable area
but not a repeatable point contact
when asked to open wide and close the

63. Record bases are constructed in the
usual way with the following
exceptions:
In the maxilla, the wax rim used to
record the centric occlusion
registration record is widened on the
un resected side towards the palatal
side in order to account for deviation
of the mandible.

64. • Vertical dimension of occlusion
is difficult to determine due to
mandibular deviation and
impaired motor and sensory
function.
Traditional methods are
contraindicated hence VDO is
recorded with mandible closing
as much as possible.
VDO determination should rely on
lip competence, facial appearance

65. Centric occlusion registration is done
with wax, plaster or any other
recording media.
The patient is instructed to move the
mandible as far as possible toward
the untreated side. Then patient was
asked to close with his own muscular
force when the mandible was
manually guided. This records a
functional maxillo mandibular
relationship which the patient can
attain.

66. Teeth selection and
arrangement• Artificial denture teeth of zero degree
cuspal angulations are selected and
arranged to achieve monoplane
occlusion and to allow for lateral
freedom of mandibular movements.
• With the lingual inclination of the
residual mandible, and with elevation
of the buccal shelf, placement of
posterior teeth to the buccal of the
residual alveolar ridge centers the
forces of occlusion more favorably

67. • After all the mandibular teeth and
the maxillary teeth have been
arranged, ramps are developed for the
maxillary prosthesis in base plate
wax. These ramps usually 5-10mm
wide and should provide 2-4mm
horizontal overlap with the
mandibular posterior teeth.
• Depending upon severity of deviation,
the ramp on the nonsurgical side
usually extends palatal to the
maxillary alveolar ridge, and the
ramp on the surgical side extends

68. Palatal Augmentation
Prosthesis
• These patients have difficulty in
valving the tongue against the palate
for appropriate speech sounds and to
manipulate food bolus in mastication
and swallowing.
• This is due to loss of tissue bulk and
motor movement of the tongue.

69. • This prostheses involves shaping the
contours of a palatal base plate, either
retained by maxillary dentition or
maxillary complete denture.
• In normal tongue-palate relationship,
the palate CUPS around the tongue at
rest and in function.

70. • Hence contours of palatal augmentation
prostheses should also CUP around the
residual/deviated tongue.
• Repeated movements of tongue will allow
the clinician to add wax to the base plate to
establish occlusal contact.
• Thickness is increased until the tongue
contacts the palate in swallowing.

71. Cast partial denture
• Indicated for patients with marginal
mandibulectomies
• Ideal prosthesis bearing surface is
split thickness graft ; it is thin,
firmly attached to the mandible and
will not move with movement of
tongue , floor of mouth or cheek

72. Pick up impression or functional reline
is needed
Removable framework should follow
routine parameters of design related
to support, stability and retention.

73. Marginal mandibulectomy
patient resurfaced with skin
graft

74. Fabrication of framework

75. Sectional Denture
• Two part denture designed to engage and
utilize opposing proximal undercuts on
mesial and distal abutment teeth, which
will result in positive retention in both
vertical and lateral direction often without
incorporating a conventional clasp.
• Each part of the denture will therefore have
its individual path of insertion and once in
position the part will be maintained in
position by means of a locking bolt to form
a whole unit.
• The technical construction of such an

76. Management of mandibular

77. Methods to minimize
deviation
• Use of skin grafts and flaps for
wound closure
• Inter maxillary fixation at time of
surgery
• Intense physiotherapy to minimize
deviation

78. IMF
• Aramany and Myers advocated the
use of inter maxillary fixation with
arch bars and elastics for 5-7 weeks
immediately after surgery.
• This type of fixation maintains the
residual mandible in the proper
maxillo mandibular position and
permits healing of the defect and the
associated scar formation with the
teeth in occlusion.

79. • If Inter maxillary fixation is
used in immediate post-
operative period,
very little muscle retraining
may be needed.
• The degree of deviation seems
to be inversely proportional to
the length of time the

80. Gunning splints can be
used for IMF in edentulous
patients.

81. VACCUM FORMED PVC
SPLINTS
• Following the removal of inter
maxillary fixation, early progression
to a more definitive appliance can be
facilitated by using an intermediate
Vacuum formed PVC appliance.
• Upper & Lower splints are fused
together in maximum inter cuspation
by interposing a further layer of the
heated polymer.

82. • Jaw movements are thus gently
restrained and guided by the soft
plastic splint making it comfortable
for the patient to wear.
• The appliance may also be worn at
night-time
• This appliance has a relatively short
shelf life and needs to be replaced by a
more definitive acrylic or metal
appliance once the patient adapts to

83. On closure of jaws the lower teeth and
mandible are readily and easily guided
into the lower half of the splint by its
flanges and indentations into the correct

84. MANDIBULAR GUIDANCE
PROSTHESIS
In discontinuity defects mandibular
guidance therapy can be instituted to
retrain the patient’s neuromuscular
system to provide an acceptable
maxillo-mandibular relationship of
the residual portion of the mandible
which permits occlusion of the
remaining natural teeth

85. Classification
1) Palatal based guidance prosthesis
• Maxillary inclined plane prosthesis.
• Positioning prosthesis with palatal
flange
• Widened maxillary occlusal table
2) Mandibular based guidance
prosthesis

86. Maxillary inclined plane
prosthesis.• The prosthesis is retained using inter
proximal ball clasps or adam’s clasps.
• Mandibular closure results in the
progressive sliding of the remaining
mandibular teeth up the incline in a
superior and lateral direction until the
occlusal contact is reached.

87. Positioning prosthesis with palatal
flange
• Patients who are able to use their pre
surgical inter cuspal position after
mandibular resection often complain
of inability to prevent the mandible
from deviating towards the defect
side during sleep.
• On awakening they have difficulty
reestablishing normal occlusal
contact.

88. • Flage extending from palate inferiorly into
the lingual vestibule between lateral border of
tongue & lingual surface of the mandible can
be formed in the mouth with auto
polymerizing acrylic resin.
• Prevent medial deviation of un resected
mandible even when the mouth is open.
• The flange should contact only the lingual
surfaces of mandibular teeth and it should
not impinge on the lingual mucosa of the
mandible throughout the opening and closing

90. Widened maxillary occlusal
table
• Patients who cannot attain the ideal
medio lateral position of the
remaining segment and an acceptable
occlusal contact of the teeth, in spite
of the use of various guidance
prostheses, a palatal ramp or a
widened maxillary occlusal table
using double row of teeth may be
used.
• Provide a surface against which the

91. Palatal Ramp to widen
maxillary occlusal table

92. Twin occlusion to widen
maxillary occlusal table

93. Mandibular lateral guide flange
prosthesis
• Used in patients who can achieve
proper medio lateral position of the
mandible but cannot hold that
position for adequate mastication.

94. • The guide flange is attached to a cast
mandibular removable partial denture.
• It can be either molded in wax at the try-in
stage and processed in clear acrylic resin
or a heavy wire loop may be used.
• The guide flange is extended into
maxillary muco-buccal fold superiorly &
diagonally on non defect side without

95. Implant supported
prosthesis

96. Advantages of
reconstruction using osseo
integrated implants
• They provide stability and retention for the
prosthesis.
• They allow the use of a fixed or removable
prosthesis.
• It avoids the preparation of remaining teeth
as abutments.
• It avoids the problems of the tissue borne
prosthesis.

97. • For many resection patients, usually
2 -3 properly positioned implants are
needed.
• Implants should not be placed close
to the border of the resected mandible
because the bone in this region may
be necrotic or poorly vascularized,
secondary to the previous surgical
procedure.

98. Implants placed in the fibular
graft 6 months after
reconstruction

99. Unilateral partial denture
retained by ball
attachments on the implants
and one clasp on the
remaining dentition

100. Final prosthesis

101. Conclusion

102. • Prosthodontic success in the
mandibular resection patient is
closely allied with the surgical
reconstruction.
• MVFFs has revolutionized
reconstruction of the mandible and
contiguous oral structures.

103. • Prosthodontic modifications to
routine prosthodontic procedures are
necessary to compensate for deficits
that are not correctable with surgical
reconstruction
• The maintenance of facial form,
prevention of tethering of intraoral
tissues have greatly enhanced the
results obtained by prosthodontic

104. References• Ackerman AJ The prosthodontic management of oral and
facial defects J Prosthet Dent,1955;5:413-432
• Scannel JB Practical considerations in dental treatment of
patients with head and neck cancer J Prosthet
Dent,1965;15:764-778
• Kelly EK Partial denture design applicable to the
maxillofacial patient J Prosthet Dent,1965;15:168-173
• Swoope CC Prosthetic management of resected edentulous
mandibles J Prosthet Dent,1969;21:197-201
• Cantor R and Curtis TA Prosthetic management of edentulous
mandibulectomy patients Part 1 J Prosthet Dent,1971;25:447-
455, Part 2 J Prosthet Dent,1971;25:547-555, Part 3 J
Prosthet Dent,1971;25:671-78.

105. • Armany MA and Meyers EN Intermaxillary fixation following
mandibular resection J Prosthet Dent,1977;37:437-443
• Desjardins RP Occlusal considerations in partial
mandibulectomy patients J Prosthet Dent,1979;41:308-311
• Shifman A and Lepley JB Prosthodontic management of
postsurgical soft tissue deformities associated with marginal
mandibulectomies J Prosthet Dent,1982;48:178-183
• Clinical maxillofacial prosthetics, Thomas D Taylor;1st
edition
• Maxillofacial prosthetics, Varoujan A Chalian
• Maxillofacial prosthetics, postgraduate dental hand book
series,Vol 4 William R Laney
• Removable partial prosthodontics,Alan B Carr;11th
edition
• Clinical removable partial prosthodontics,Kenneth L Stewart;2nd