3. Classification of mandibular defects
Cantor and Curtis
Class I -Radical
alveolectomy with
preservation of
mandibular continuity
Class II - Lateral
resection of the
mandible distal to the
cuspid area
Firtell DN, Curtis TA, Removable partial denture design for the mandibular
resection patient, J Prosthet Dent 1982; 48(4):437- 443
4. Class III - Lateral
resection of the mandible
to the midline
Class IV - Lateral bone
graft and surgical
reconstruction
Firtell DN, Curtis TA, Removable partial denture design for the mandibular
resection patient, J Prosthet Dent 1982; 48(4):437- 443
5. Class V - Anterior bone
graft and surgical
reconstruction
Class VI - Anterior
mandibular resection
without surgical
reconstruction
Firtell DN, Curtis TA, Removable partial denture design for the mandibular
resection patient, J Prosthet Dent 1982; 48(4):437- 443
6. HCL (Boyd and colleagues classification)
H - lateral defects of any length up to midline
including condyle
C - defects involve central segment containing 4
incisors and 2 canines
L - lateral defects excluding the condyle
3 lower case letters describe soft tissue
component
o – no skin or mucosa
s – skin
m – mucosa
sm – skin and mucosa
Maurer et al, Scope and limitations of methods of mandibular reconstruction: a
long-term follow-up, Brit J Oral Maxillofacial Surgery 2010;28:100–104
7. Maurer et al, Scope and limitations of methods of mandibular reconstruction: a
long-term follow-up, Brit J Oral Maxillofacial Surgery 2010;28:100–104
8. Urken et al Classification
Based on functional considerations caused by
detachment of different muscle groups and
difficulties with cosmetic restoration
C – condyle
R – ramus
B – body
S – total symphysis
SH – hemi-symphysis
Mehta RP, Deschler DG, Mandibular Reconstruction in 2004: An Analysis of
Different Techniques, Current Opinion in Otolaryngology & Head and Neck
Surgery, 2004;12:288-293.
9. Mehta RP, Deschler DG, Mandibular Reconstruction in 2004: An Analysis of
Different Techniques, Current Opinion in Otolaryngology & Head and Neck
Surgery, 2004;12:288-293.
10. Goals of Mandibular Reconstruction
Restore form and function
• Restore bony contour of native mandible
• Restoration of mastication
Deglutition
Articulation
Maintainance of the airway
11. Diagnostic considerations
Location and extent of the mandibular defect
Presence of remaining teeth
Degree of post mandibulectomy rotation and deviation
Available mouth opening
Functional limitation of the tongue
12. Location and extent of the mandibular
defect
Loss of mandibular continuity/ without loss
Radical alveolectomy
- Loss of vertical ridge height and vestibular depth
- Reduction in stability
13. Location of defect
Farther anterior the defect the more the disfiguring
(facial appearance)and functional disability
Anterior defects – symphyseal region – debilitating
functionally – muscle attachments
Molar region defects – near normal mandibular function
14. Presence of remaining teeth
Determines the prognosis of rehabilitative therapy
Presence of teeth – better retention, stability and
support
Mandibular incisors – abutments – indirect retention
15. Degree of post mandibulectomy rotation
and deviation
Loss of mandibular continuity – deviation towards the
defect
Vertical rotation of residual segment inferiorly
- suprahyoid muscles
- gravity
Facial disfigurement, loss of occlusal contact, lack of saliva
control
16. Treatment for mandibular rotation and
deviation
Restoration of continuity by osseous grafting
Physical therapy – stretching exercises,
reposition training
18. Maxillary palatally positioned
guidance ramp
When deviation is less severe
Not indicated in edentulous patients – lateral
forces on complete dentures cannot be taken
up
19. Available mouth opening
Trismus and scar/ fibrosis – post-
operatively
Insert a stock mandibular impression tray
in the mouth
Post surgical trismus - Stretching
exercises, moist heat and analgesics
20. Functional limitation of the tongue
Wound closure limit tongue mobility
Speech, swallowing, mastication and control of food
bolus and ability to control a removable prostheses
Posterior resection of tongue more debilitating than
anterior tongue resection
22. Implant rehabilitation
Grafted bone limited- length, diameter and
number of implants less than ideal
Bone plates and screws to be removed
23. Surgical Reconstruction
The amount of remaining soft tissue
The size, extent and prognosis of the tumor
requiring resection
The age and general health of the patient
Location of the resection
25. Prosthodontic rehabilitation of partially
edentulous patients
Lateral discontinuity defects
Lateral defects with anterior teeth present
Arc of closure – angular
26. Altered cast impressions
Establish lingual extension of unresected side-
enhance stability and retention
Coverage of buccal shelf on unresected side –
maximize support
Extend impression into soft tissue on resected
side
Mould the cheek and tongue from side to side
27. Clinical procedures
Centric occlusion jaw relation record
Records with soft wax and minimum pressure
Force of contracture increases on unresected side –
resected side moves downward out of occlusion
If severe trismus present – VD to be reduced to
facilitate insertion of bolus b/w teeth
28. Defects with mandibular continuity
Anterior defects
Patients with anterior inner table resections
Anterior composite resections - mandibular
continuity is re-established by reconstructive
surgery
patients have posterior teeth and extensive
anterior edentulous area – Kennedy class IV
partial denture
Posterior occlusion rarely altered
29. Anterior defects
Surgically restored anterior discontinuity defects –
occlusal abnormalities because of graft contracture ,
inaccurate positioning of the residual mandibular
segments.
Prostheses – enhance esthetics, support for lower lip
and cheek, improved articulation of speech, control of
saliva
30. Implant retained prosthesis
At least 10 mm of vertical bone
Implants can be placed in residual bone or
free grafts
Implants placed in the grafts 6- 9 months
later
Removable overlay prosthesis preferred
for restoring the defects
31. Lateral defects
Posterior dentition
remains on only one
side of the arch
Conventional partial
denture
Implant retained
32. Factors compromising function with
complete dentures
Compromised retention, stability and support
Reduced saliva output – radiation / excision
Angular pathway of mandibular closure-
dislodge the denture
Abnormal jaw relationships
Neuromuscular imbalance
33. Impressions
Preliminary impression - Maximum tissue coverage
Retention – close adaptation of the prosthesis with the
bearing surface , extending lingual periphery maximally
in the unresected side.
Polished surface accurately recorded – tongue retains
the denture
Primary support area – buccal shelf on unresected side
Functional impression of polished surfaces of
mandibular prosthesis
34. Centric registrations
Maxilla – wax rim widened on unresected
side to account for the deviation of the
mandible
Vertical dimension at rest difficult to
determine
Evaluation of phonetics and closest speaking
space – best method for VD
35. Occlusal schemes
Non anatomic posterior teeth
Neutral zone
Mandibular posterior teeth – unresected side – buccal to
crest of edentulous alveolus
Resected side – lingual to crest of edentulous ridge
Contour and support – lip and corner of the mouth –
thickening the denture flange below the crest of the ridge
Mastication – non defect side
36. Processing, delivery and follow up
Patients monitored closely during post
insertion period
Use of prosthesis for mastication deferred
for a week
37. Implant retained and supported
overlay denture
Osseointegrated implants – fabrication of well
retained and stable overlay prosthesis
Minimum of 2 implants placed
15 mm apart to accommodate retention bar
apparatus
38. Avinash C K A et al, Prosthetic management of partially resected dentulous
mandible, Indian J Dent Adv 2011; 3 (1): 750-753
39. References
Beumer J, Curtis TA, Marunick MT, Maxillofacial
rehabilitation Prosthodontic and surgical
considerations,1st edition, lshiyaku Euro America
publications, St Louis, 1996, Pp 113- 224
Taylor TT, Clinical maxillofacial prosthetics, 1st edition,
Quintessence Publications, Illinois, 2000,
Pp 155- 188
Cantor R, Curtis TA, Prosthetic management of
edentulous mandibulectomy patients -part II, Clinical
procedures, J Prosthet Dent 1971;25:546-55
40. Firtell DN, Curtis TA, Removable partial denture design
for the mandibular resection patient, J Prosthet Dent
1982; 48(4):437- 443
Maurer et al, Scope and limitations of methods of
mandibular reconstruction: a long-term follow-up, Brit J
Oral Maxillofacial Surgery 2010;28:100–104
Mehta RP, Deschler DG, Mandibular reconstruction in
2004: An analysis of different techniques, Current
Opinion in Otolaryngology & Head and Neck Surgery,
2004;12:288-293.
Editor's Notes
Infr border of mand muscles of mastication r retained.
Condyle ramus postr prtion of body of mand is removed. And fn of attached muscles has been lost. Deviation of mand toward the surgical side is seen
Most of mand resection pts r found in this class
3- or even beyond. In addition to what is removed in class 2. anteriorportion of mandible is also resected
4-pt has a lateral resection and subsequent bone augmenation. Articulation with temporal bone has not been restored but there id less mand deviation
5- pt has mand resection which crosses the midline and articulation with the tnj has been maintained
6-similar to class 5 but the continuit has not been restored surgically
Another classification to to categorise the defects in the mand and adj soft tissue
H - hemimandibular continuity defect
C- central continuity defect
L lateral continuity defect
Mand reconstruction shud allow for deglutition articulation and airway
Resection of alveolar process without loss of continuiyt is less disfiguring when compared to with. Farther anterior the defect more disfiguring it will be. Anterior more debilitating cos of loss of key muscle attachments geniohyoid and genioglossus that ctrl tongue fn and mobility. Defects in molar region more easy to correct when compared to other regions.
Particularly when the elevator muscles on the defect side remain intact
In molar region only a linear graft will be reqd for the reconstruction when compared to the curved type of reconstruction reqd for the antr mandible
Mans incisors cud serve as abutments where the canine tooth has been lost on the defect side
This will help to limit the scar formation at the resection site
These devices can be used when the residual mandible can be easily guided bck into its position either by the clinician or the pt. these can be used only when minimum force is reqd to guide the mand. If more force is reqd use a max casting with buccal bar against which mnad prostheses can slide, the max casting will splint and protect the surfaces of the maxillary teeth againt whicvh the guidance prostheses functions
Are not indicated when dental Im plants are not used to stabilise the denture
Many pts experience limited mouth opening following mandibulectomy sirgery. Excercises such as placing finger on mand and pull it downward. Excercises shud be started within 2 weeks preferably 1 week after surgery
Wound closure mainlt done by suturing the remaining tissues of floor of mouth and tongu to the remining buccal tissues. We can chek the tongue mobility by asking the pt to lick the lips. Postr more debilitaiting than anterior cos of there can be loss of both motor and sensory ineervation in floor of mouth and base of tongue resections
Prosthodontic rehabilitaion is closely dependent on vestibular extensions for proper retention suppotr stability and peripheral seal
Volume of hgrafted bone available for placing the implants is limited. If bones and plates are present and they r in contact with the endosseous implants erosion can occur.
When implant rehabilitaion of the bone grafted mateerial is done, the most common oprob which is seen is the excessive interarch space
Becos of the limited width of the graft bone
Becos after the primary resection may require soft tissue augmentatation
Many small tumors can be immediaely reconstructed, malignant tumor wait for 1 yr.
reconstruction can either be immediate or delayed.
Alloplastic implants are titanium ss co cr. They r particularly useful for immediate separation and stabilisation of the residual fragmants. They can also be used in [pts who r not good candidates for bone grafts
Arc of closure of mandible is more angular that vertical
PROducing forces of occlusion that are entirely unilateral and on the non resected side
After the cast partial framework is verified , an altered cast impression of the edentulous areas is obtained.
In most cases this movement is accepted and no attempt is made to correct it.
In case of lateral discontinuity defects. Complete dentures in thse pts is on;ly for esthetics