Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.
Presented by – Dr. Dwij Kothari
Darshan Dental College and Hospital
Contents
 Introduction
 Classification of mandibular defects
 Factors affecting treatment of mandibulectomy
patients
 ...
 Resection guidance restoration
 Guidance prosthesis
 Speech aids and speech therapy
 Tongue prosthesis
 Prosthetic r...
 Prosthetic rehabilitation of edentulous patient
 Management of discontinuity defect
 Factors determining prosthetic pr...
Introduction
 Mandible is a single bone that creates:
 Peripheral boundaries of the floor of the mouth
 Facial form
 Speech
 Swall...
 Rehabilitation of mandibulectomy patients should
therefore consider both form and function.
 Surgical resection of tumor often includes a partial
mandibulectomy resection, a partial glossectomy , a
partial resecti...
Classification of mandibular defects
According to Laney(1979)
Based on etiology
1. Acquired: - Marginal
- Segmental :- a) ...
2. Congenital
- Incomplete formation
- Incomplete ossification
i.e. hypoplasias, mandibulofacial dysostosis,etc
3. Develop...
Based on amount of resection (Laney)
 Continuity defect
(marginal resection)
- Inferior border and its continuity
preserv...
According to Cantor and Curtis (1971)
Class 1 : Radical alveolectomy with preservation of
mandibular continuity
Tissues resected :
 Portion of alveolar process and body
of mandible
 Lingual and buccal sulcus mucosa
 Portion of base...
FEATURES:-
1. Least debilitating.
2. Sometimes resection of part of mylohyoid muscle and resultant scarring
can raise the ...
Class 2 : Lateral resection of mandible distal to cuspid
Tissues resected:
 Condyle, ramus and body of mandible
distal to cuspid
 Mylohyoid, hypoglossal
 Pterygoid, masseter, e...
FEATURES:-
1. Speech, swallowing, saliva control, manipulation of food impaired.
2. Facial disfigurement apparent.
3. Disa...
Class 3 - Lateral resection of the mandible to the midline
Tissues resected :
 All those described in class 2 in addition to the anterior portion of the
mandible, geniohyoid, genio...
FEATURES:-
1. Restricted tongue mobility due to loss of tip of tongue and
genioglossus muscle.
2. Speech, swallowing, sali...
Class 4: Lateral bone graft surgical reconstruction
 Lateral bone and split
thickness skin or pedicle graft
can be performed on patients
who have had:
- radical alveolectomi...
 3 Types of bone grafts are possible:-
1. Mandibular augmentation procedures.
2. Bone graft that connect a residual condy...
Class 5 :Anterior bone graft surgical reconstruction
 Tissues resected :
 anterior portion of the mandible
 large bilateral portions of mylohyoid,
geniohyoid
 genioglossus...
 The mucosa retained in the labial and buccal regions is sutured to the
residual stump of the tongue and a Kirschner wire...
Predisposing factors
 Dentures – Chronic irritation – epidermoid carcinoma
– squamous cell carcinoma
 Alcohol – squamous cell carcinoma in th...
Factors affecting treatment of
mandibulectomy patients
1. Location and extent of mandibular defects
Radical alveolectomy
- Least debilitating.
- Main problems – loss of vertical...
Discontinuity defects
RULE OF THUMB:-The further anterior the defect, the more
disfiguring and functionally debilitating
i...
- Most debilitating and difficult to treat.
- Greatest facial disfigurement.
- Surgical reconstruction necessary or at lea...
2. Presence of remaining natural teeth/pre-existing
implants
Patients after mandibulectomy present with few or no
remainin...
Greater the number of teeth, better the prognosis
- Teeth present on both sides of the midline permit greater
prosthesis s...
Ideal for rehabilitation
 A maxillary complete denture will function well for
mandibulectomy patient against a reconstructed mandibular
dentition
...
3. Degree of post mandibulectomy rotation and deviation
- Loss of mandibular continuity causes deviation of the
remaining ...
Rotation:- Due to
- Pull of the suprahyoid muscles on the residual mandibular
fragment causing inferior displacement and r...
 Prosthodontic prognosis in such patients can be improved by
early post resection physical therapy to reposition the
mand...
4. Available mouth opening
- Trismus –due to surgical trauma
- Scar tissue formation will further reduce mouth opening.
- ...
5. Functional limitation of the tongue
- Frequently the surgical wound is closed by suturing the
remaining tissues of the ...
- Lingual vestibuloplasty and skin or mucosal grafting can be
used to improve tongue mobility
- Evaluation of tongue mobil...
 Loss of sensory innervation will compromise tongue function
and prognosis of prosthodontic rehabilitation.
If lingual ne...
6. Compromise of vestibular extensions
 Vestibular depth is critical for stability and peripheral seal.
 It is also crit...
7. Skin grafting
 Skin grafts are used for surgical reconstruction either as lining for
the surface of resected soft tiss...
8. Radiation therapy
 Careful treatment planning is required for patients with
radiation therapy.
 Irradiated tissue is ...
9. Altered anatomic relationships following restoration
of mandibular continuity
 Reconstruction of anterior defects
- Mo...
- Inability to control food bolus due to lack of motor function of
lips and muscles of the lower face.
- Excessive display...
 Reconstruction of posterior defects
- More predictable from prosthodontic point of view as compared
to anterior defects....
Angled dental implants- the prosthesis they support must be
cantilevered lingually to permit tooth contact.
Inadequate spa...
Immediate vs delayed reconstruction
 Factors determining whether to reconstruct at the
time of tumor resection (immediate...
 Extensive soft tissue loss – require additional procedure
for soft tissue augmentation, thus precluding
immediate graft....
 The size, extent and prognosis of tumors requiring
resection are important factors.
 Relatively small defect – immediat...
 Medically compromised patients – observe the response
to primary surgery before subjecting to second
procedure
 Locatio...
Relating surgical considerations to
prosthodontic treatment
 Marginal mandibulectomy:-
Soft tissues are mainly used to reconstruct marginal
mandibulectomies.
They may be: - Skin gra...
 Discontinuity mandibulectomy:-
- Previously soft tissue local flaps (mainly the residual tongue
sutured to the border of...
Mandibular malposition after bony reconstruction
 May be due to:
1. Minimal proximal mandible on the surgical
side to att...
4. The bone grafts used i.e the fibula and the iliac crest graft
have some inherent problems:
- Lacks height compared to t...
Prosthetic Rehabilitation of
mandibulectomy patients
Mandibular Guidance
 Loss of continuity of the mandible destroys the balance and
symmetry of mandibular function
 Leadin...
Intermaxillary Fixation
 One approach to reducing the deviation associated with
resection of the mandible
- use arch bars...
Resection guidance restorations
 If intermaxillary fixation is not employed –
2weeks postsurgically, the patient should b...
 If extensive resection and a considerable period of
time has elapsed, guidance procedures are much more
difficult and a ...
Guidance prosthesis
 Robinson and Rubright described Mandibular
guidance prosthesis
 It consists of a RPD framework with...
 If the completed guidance ramp is to be
formulated in acrylic resin,
autopolymerizing material is added to the
prosthesi...
 Palatally based guidance restoration
 This is a guidance ramp and an index to a maxillary
prosthesis.
 Indicated for p...
 The full palatal coverage prosthesis is constructed
following conventional prosthodontic guidelines.
 A mix of autopoly...
 The patient should be able to close into the index with
appropriate manual manipulation of the mandible.
 When the pati...
Speech aids and speech therapy
 Cantor et al 1969, noted speech improvement by lowering
palatal vault prosthetically into...
 Scott 1970, investigated the potential benefit of intensive
speech therapy for mandibulectomy patients and
concluded tha...
Tongue prosthesis
 The loss of tongue impairs functions of stomatognathic
system.
 Moore 1972, suggested that tongue pro...
Prosthetic Rehabilitation of
Dentulous Patients
Lateral Discontinuity Defects
(Class 2 And 3)
 Often resected in the region of 2nd premolar and 1st
molar. If there are n...
 The forces of occlusion are unilateral and consequently
the axis of rotation (fulcrum line) of the partial
denture devia...
 Major connector – depends on the
height of floor of the mouth.
 Minor connector – minimize the
stress on abutment teeth...
 If anterior and posterior teeth from resected side
missing and posterior teeth on unresected side are
missing, prosthesi...
 Maxillomandibular records – made with soft wax and
minimum occlusal pressure applied.
 Acrylic resin teeth
 When less ...
 Class 3 resection – defect to the midline or
farther toward the intact side, leaving half
or less of the mandible remain...
Defects With Mandibular Continuity
Anterior Defects (Class 5)
 Patients with anterior inner table resections and
patients...
 Indirect retention – long
mesial rests on the 2nd Molars
 Minor connector – relieve
distal aspect and proximal
plates
...
 Esthetics, occlusion and speech – verify at try-in stage
 Prosthesis is delivered with periodic monitoring.
Defects with Mandibular Continuity
Lateral Defects (Class 1, 4)
 Inferior border of the mandible is intact, and normal
mo...
 Anterior marginal resections some times include part
of the anterior tongue and floor of the mouth.
 The remaining teet...
 Extremely long lever arms & compromised edentulous
bearing surfaces contribute to excessive movement of
prosthesis durin...
 The occlusion should be refined to achieve contact in
centric occlusion only and patient should be
instructed to mastica...
Prosthetic Rehabilitation of
Edentulous Patients
Management Of Discontinuity Defects
 Complete dentures in these patients are primarily for
esthetics.
 They improve lip ...
Factors Determining The Prosthetic
Prognosis For Complete Dentures
 The prognosis is more favourable if the resection is
...
 Post surgical lip posture and control, does have
important prosthodontics implications.
 Due to radiation therapy, ther...
Impression
 Primary impression – irreversible hydrocolloid
impression material
 Final impression – border moulding with ...
Centric Registration
 In maxilla, wax rim used – widened on unresected side
in order to account for deviation of the mand...
Occlusal schemes and Lateral registrations
 Swoop 1969, suggested “non anatomic teeth” for
patients with abnormal jaw rel...
 Special attention should be paid of developing
appropriate contours of the rim in contact with the
inside of the upper a...
 It is advisable to place the maxillary anterior teeth
lingual to, and mandibular anterior teeth labial to,
their accusto...
 Generally, in mandible the posterior teeth on the
unresected side will be buccal to the crest of
edentulous alveolus, es...
 Contour and support for the corner of the mouth and
the lop on the resected side are best accomplished by
thickening the...
 After tooth arrangements have been finalized, the occlusal
contact of the mandibular teeth is checked with the
maxillary...
Anterior Border Defects
 The prognosis is usually favorable especially if a
vestibuloplasty has been completed.
 The man...
Review of literature
 They supported this concept by quoting Fish (1933) who gave
this concept, and stressed on the importance of polished
sur...
 In this method short and narrow artificial teeth which will
not interfere with the denture space were selected.
 They w...
 A functional impression of the defect side is made using
modelling compound for muscle trimming and is
completed with an...
Cantor and Curtis(1971): Swallowing technique
in edentulous patient
 A preliminary alginate impression of the mandibular
...
 Modeling compound “stops” are placed under the column
tray for stability and to provide space for the impression
materia...
 The lower part of the oral cavity is filled with an alginate
impression material that has been mixed with approximately
...
 The mandible is then closed until the maxillary ridge rests
are properly seated, and the custom tray is securely in plac...
Swatantra agarwal, Praveen G, Samarth Kumar
agarwal and Sankalp sharma (2011), suggested Twin
Occlusion in which they did ...
Maxillary arch representing
kennedy’s class I
Bite record
OPG reveals resection of mandible of left side
Intercuspation obtained by twin
occlusion on nonresected side
Mounted cast on articulator with
arrangement of teeth
Occlusal view of definitive prosthesis
placed in maxilla
Summary & Conclusion
 Management of mandibular defects is one of the most
challenging aspects of maxillo-facial prosthetics. These
defects aff...
 On his part the prosthodontists should be able to
efficiently plane and execute treatment because the scope
of patients ...
References
 John Beumer, Maxillofacial rehabilitation prosthodontic and surgical
reconstruction, 1st edition 1979
 Taylo...
 Cantor R and Curtis TA Prosthetic management of edentulous
mandibulectomy patients - Part 1. J Prosthet Dent, 1971; 25:4...
 Desjardins RP Occlusal considerations in partial mandibulectomy
patients . J Prosthet Dent, 1979; 41:308-311.
 Kelly EK...
 Scannell JB Practical considerations in dental treatment of patients
with head and neck cancer. J Prosthet Dent, 1965; 1...
Management of aquired mandibular defect / mandible defect management
Management of aquired mandibular defect / mandible defect management
Management of aquired mandibular defect / mandible defect management
Management of aquired mandibular defect / mandible defect management
Management of aquired mandibular defect / mandible defect management
Upcoming SlideShare
Loading in …5
×

Management of aquired mandibular defect / mandible defect management

6,370 views

Published on

MANAGEMENT OF AQUIRED MANDIBULAR DEFECT
Dr. Dwij Kothari
Darshan Dental College and Hospital, Udaipur

Published in: Education
  • Login to see the comments

Management of aquired mandibular defect / mandible defect management

  1. 1. Presented by – Dr. Dwij Kothari Darshan Dental College and Hospital
  2. 2. Contents  Introduction  Classification of mandibular defects  Factors affecting treatment of mandibulectomy patients  Immediate vs Delayed reconstruction  Relating surgical considerations in mandibulectomy patients  Prosthetic rehabilitation of mandibulectomy patients  Mandibular guidance  Intermaxillary fixation
  3. 3.  Resection guidance restoration  Guidance prosthesis  Speech aids and speech therapy  Tongue prosthesis  Prosthetic rehabilitation of dentulous patient  Lateral discontinuity defect (class 2 & 3)  Defects with mandibular continuity anterior defect (class 5)  Defects with mandibular continuity lateral defect (class 1 & 4)
  4. 4.  Prosthetic rehabilitation of edentulous patient  Management of discontinuity defect  Factors determining prosthetic program for CD  Impression  Centric registration  Occlusal schemes and lateral registration  Anterior border defects  Review of literature  Summery and conclusion  References
  5. 5. Introduction
  6. 6.  Mandible is a single bone that creates:  Peripheral boundaries of the floor of the mouth  Facial form  Speech  Swallowing  Mastication  Respiration  Disruption of the mandible has the potential to disrupt any of these.
  7. 7.  Rehabilitation of mandibulectomy patients should therefore consider both form and function.
  8. 8.  Surgical resection of tumor often includes a partial mandibulectomy resection, a partial glossectomy , a partial resection of the floor of the mouth and a radical neck dissection.  The extent of surgery and effect of radiation therapy and chemotherapy determine the amount of rehabilitation needed to a patient.
  9. 9. Classification of mandibular defects According to Laney(1979) Based on etiology 1. Acquired: - Marginal - Segmental :- a) Lateral to midline - Body only - Ramus- Body with disarticulation b) Anterior body - Subtotal - Total
  10. 10. 2. Congenital - Incomplete formation - Incomplete ossification i.e. hypoplasias, mandibulofacial dysostosis,etc 3. Developmental as a result of postnatal insults i.e. trauma during birth, surgery,etc
  11. 11. Based on 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 - from alveolar crest to inferior border removed - Mandible deviates to resected side - Marked facial disfigurement - Occlusion altered - Can be :- lateral discontinuity defect midline discontinuity defect
  12. 12. According to Cantor and Curtis (1971) Class 1 : Radical alveolectomy with preservation of mandibular continuity
  13. 13. 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 Submaxillary salivary glands  Sometimes anterior part of digastric muscle
  14. 14. FEATURES:- 1. Least debilitating. 2. Sometimes resection of part of mylohyoid muscle and resultant scarring can raise the floor of the mouth causing reduction in tongue mobility. 3. Ability to shape and control the tongue form may be lost due to loss of some intrinsic muscles. 4. Resection of lingual and inf. alveolar nerves results in a loss of sensation in the mucosa of cheek, alveolar process, lower lip and loss of taste on anterior 2/3rd of the tongue.
  15. 15. Class 2 : Lateral resection of mandible distal to cuspid
  16. 16. Tissues resected:  Condyle, ramus and body of mandible distal to cuspid  Mylohyoid, hypoglossal  Pterygoid, masseter, external pterygoid,  Palatoglossal muscles, most of intrinsic muscles of tongue.  Hypoglossal , lingual and inferior alveolar nerves.  Sublingual & Submaxillary salivary glands.  Mucoperiosteum & adjacent buccal & lingual sulcus mucosa
  17. 17. FEATURES:- 1. Speech, swallowing, saliva control, manipulation of food impaired. 2. Facial disfigurement apparent. 3. Disarticulation and loss of muscles of mastication will hamper mandibular movements. 4. Taste, sensory and motor losses are more extensive as compared to class 1.
  18. 18. Class 3 - Lateral resection of the mandible to the midline
  19. 19. Tissues 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.
  20. 20. FEATURES:- 1. Restricted tongue mobility due to loss of tip of tongue and genioglossus muscle. 2. Speech, swallowing, saliva control and manipulation of food is 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. 5. Scarring of orbicularis oris can interfere with expression of emotion
  21. 21. Class 4: Lateral bone graft surgical reconstruction
  22. 22.  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. -midline resections with or without disarticulation.
  23. 23.  3 Types of bone grafts are possible:- 1. Mandibular augmentation procedures. 2. Bone graft that connect a residual condyle with the large mandibular fragment. 3. Lateral bone grafts that extend from the mandibular fragment into the defect area to establish a pseudo TMJ.
  24. 24. Class 5 :Anterior bone graft surgical reconstruction
  25. 25.  Tissues resected :  anterior portion of the mandible  large bilateral portions of mylohyoid, geniohyoid  genioglossus and anterior digastric muscles  bilateral lingual and inferior alveolar nerves  bilateral submaxillary and submandibular salivary glands  mucosa of lower lip  anterior floor of the mouth  ventral surface of the tongue
  26. 26.  The mucosa retained in the labial and buccal regions is sutured to the residual stump of the tongue and a Kirschner wire is often positioned to maintain the mandibular fragments .  Bone graft and split thickness skin graft or pedicle graft procedures can be used to restore anterior facial contour and bilateral mandibular function.
  27. 27. Predisposing factors
  28. 28.  Dentures – Chronic irritation – epidermoid carcinoma – squamous cell carcinoma  Alcohol – squamous cell carcinoma in the floor of the mouth – related to direct tissue contact or indirectly with live cirrhosis and altered nutritional status  Tobacco - cigarette , cigar, pipe , chewing tobacco  Leukoplakia – white patch - can not be scraped off – reversed by removing local irritants  Oral lichen planus – recticular, plaque, and erosive forms
  29. 29. Factors affecting treatment of mandibulectomy patients
  30. 30. 1. Location and extent of mandibular defects Radical alveolectomy - Least debilitating. - Main problems – loss of vertical ridge height and vestibular depth – decreased stability for soft tissue-supported prosthesis as well as the loss of load bearing tissues available for support. - Vertical discrepancy most important when prosthesis supported by dental implants are considered.
  31. 31. Discontinuity defects RULE OF THUMB:-The further anterior the defect, the more disfiguring and functionally debilitating it is likely to be. Osbon DB. Early treatment of soft tissue injuries of the face. J Oral Surg 1969;27:480–7.
  32. 32. - Most debilitating and difficult to treat. - Greatest facial disfigurement. - Surgical reconstruction necessary or at least segmental stabilization before prosthodontic treatment can be initiated. - Mandibulectomy defects of the molar region of the mandibular body are more well suited for surgical reconstruction compared to anterior defects. - If muscle attachments are intact – Good prognosis Near normal appearance and function is achievable. Defects of the symphyseal region
  33. 33. 2. Presence of remaining natural teeth/pre-existing implants Patients after mandibulectomy present with few or no remaining natural teeth. 2 reasons: 1. Patients at greatest risk for squamous cell carcinoma - heavy users of tobacco products and alcohol. 2. Teeth are usually extracted prior to radiotherapy to prevent complications such as osteoradionecrosis.
  34. 34. Greater the number of teeth, better the prognosis - Teeth present on both sides of the midline permit greater prosthesis support since the problem of straight line design can be avoided. - Maximum number of abutment teeth should be incorporated in the design of the prosthesis to maximize stability and dissipate functional forces.
  35. 35. Ideal for rehabilitation
  36. 36.  A maxillary complete denture will function well for mandibulectomy patient against a reconstructed mandibular dentition Exceptions:  Collapse of residual proximal mandibular stump; coronoid process against the posterior maxillary alveolus - prohibiting adequate denture flange extension.  When a guide flange prosthesis is planned to correct mandibular deviation - pressure from the guide flange will tend to dislodge the maxillary denture.
  37. 37. 3. Degree of post mandibulectomy rotation and deviation - Loss of mandibular continuity causes deviation of the remaining mandibular segment towards the defect and rotation of mandibular occlusal plane inferiorly. Deviation: Primarily due to loss of tissue involved in surgical resection.
  38. 38. Rotation:- Due to - Pull of the suprahyoid muscles on the residual mandibular 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  Loss of ability to bring lips together for saliva control & to initiate swallowing process
  39. 39.  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. 2.Mandibular resection guidance prosthesis
  40. 40. 4. Available mouth opening - Trismus –due to surgical trauma - Scar tissue formation will further reduce mouth opening. - Physical therapy (Stretching exercise) should be started immediately. - Simple test to check mouth opening: Insert a stock mandibular impression tray in the mouth. If this cannot be accomplished, rehabilitation is unlikely to occur. - Surgery can be done to release scar tissue. However, not very beneficial as it returns to the same in a short period of time.
  41. 41. 5. Functional limitation of the 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. This compromises: - Speech - Swallowing - Mastication - Control of food bolus - Ability to control removable prosthesis
  42. 42. - Lingual vestibuloplasty and skin or mucosal grafting can be used to improve tongue mobility - Evaluation of tongue mobility - Patients in whom anterior resection has been done, ability to lick the lips when the artificial prosthesis is placed in the mouth may be difficult or impossible. - In such cases consideration is given to lowering the anterior occlusal plane or arranging the teeth slightly lingually.
  43. 43.  Loss of sensory innervation will compromise tongue function and prognosis of prosthodontic rehabilitation. If lingual nerve is sacrificed - tongue on the defect side will permanently remain without any feeling. Loss of sensory capability:- Affects speech Mastication Prosthesis control on defect side Loss of sensory innervation of the buccal mucosa(long buccal nerve) and lower lip(mental nerve) will reduce patient’s ability to control food and saliva.
  44. 44. 6. 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.
  45. 45. 7. 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 from prosthesis. 3. Protects underlying bone and connective tissue well due to rapid turnover of keratin producing cells. Disadvantages 1. No sensory innervation. 2. Full thickness grafts may incorporate hair follicles. 3. Skin is not very compatible with titanium surface of implants.
  46. 46. 8. 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.
  47. 47. 9. Altered anatomic relationships following restoration of mandibular continuity  Reconstruction of anterior defects - Most difficult situation for grafting - Frequently results in a graft that is deficient anteriorly. - Results in a severe Class II like situation. The prosthodontic difficulties seen in rehabilitating such a patient are:- - Inability to provide proper lower lip support for esthetics. - Speech problems associated with mandibular dentition placed too far lingually to allow normal articulation.
  48. 48. - Inability to control food bolus due to lack of motor function of lips and muscles of the lower face. - Excessive display of mandibular teeth due to patient’s inability to maintain normal lower lip posture. - Difficulty gaining adequate space for prosthesis placement without encroaching on function of tongue. - Misalignment of remaining unresected mandibular fragments and resultant relationship between maxillary and mandibular teeth.
  49. 49.  Reconstruction of posterior defects - More predictable from prosthodontic point of view as compared to anterior defects. - The mediolateral position of the graft is frequently seen lateral to the original position of the mandibular body. - Thus the prosthesis must be built in cross bite to maintain the denture teeth over the supporting base of the bone graft.
  50. 50. Angled dental implants- the prosthesis they support must be cantilevered lingually to permit tooth contact. Inadequate space after surgical reconstruction- limits prosthesis or implant placement. Excessive space after surgical reconstruction- problem to control forces on remaining teeth or implants
  51. 51. Immediate vs delayed reconstruction  Factors determining whether to reconstruct at the time of tumor resection (immediate) or as a secondary procedure (delayed).  Amount and character of remaining soft tissue  Anatomic location of the defect  Size of bone defect  General health of patient  Prognosis for tumor control  Experience of the surgeon
  52. 52.  Extensive soft tissue loss – require additional procedure for soft tissue augmentation, thus precluding immediate graft.  If immediate reconstruction is desired but soft tissue appear inadequate for proper watertight oral closure – a forehead flap may be useful  Flaps should be – broadly based, as thick as possible.
  53. 53.  The size, extent and prognosis of tumors requiring resection are important factors.  Relatively small defect – immediate reconsturction  Spectrum malignant tumors requiring extensive hard and soft tissue resection with a radical neck dissection – immediate implant followed by delayed graft.  Since tumor recurrences occur frequently within 1st year
  54. 54.  Medically compromised patients – observe the response to primary surgery before subjecting to second procedure  Location of resection is another important factor  Defects at symphysis require immediate stabilization, or remaining mandibular fragments will colapse medially and superiorly because of muscle pull and scar contracture  Immediate stabilization is less important in lateral mandibular defects.
  55. 55. Relating surgical considerations to prosthodontic treatment
  56. 56.  Marginal mandibulectomy:- Soft tissues are mainly used to reconstruct marginal mandibulectomies. They may be: - Skin graft - Local flap - Pedicle flap - Microvascular free flaps (MVFF)  Skin grafts serve as excellent prosthesis-bearing surfaces.  However when soft tissue bulk is required or recipient bed is previously irradiated - Microvascular free flaps are the treatment of choice.
  57. 57.  Discontinuity mandibulectomy:- - 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. - Microvascularized bone is mainly obtained from: 1.Fibula- most common 2.Iliac crest - Soft tissue MVFF are obtained from: 1.Forearm 2.Rectus muscle
  58. 58. Mandibular malposition after bony reconstruction  May 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.
  59. 59. 4. The bone grafts used i.e the fibula and the iliac crest graft have some inherent problems: - Lacks height compared to the residual mandible -Pyramidal in shape being narrower at the occlusal surface -Fibula is grafted to restore inferior border of the mandible, which is necessary to restore facial form. This tends to place fibula buccally in the plane of the cheek. -Since bone is placed buccally in the cheek, implants distal to the premolar area cause constant soft tissue and infection problems.
  60. 60. Prosthetic Rehabilitation of mandibulectomy patients
  61. 61. Mandibular Guidance  Loss of continuity of the mandible destroys the balance and symmetry of mandibular function  Leading to altered mandibular movements and deviation of the residual fragment towards the surgical side.  Methods to reduce mandibular deviation  Intermaxillary fixation  Use of mandibular based guidance restorations  Use of palatally based guidance restorations
  62. 62. Intermaxillary Fixation  One approach to reducing the deviation associated with resection of the mandible - use arch bars and elastics or wire in dentulous patients. - “gunning splint” in edentulous patients.
  63. 63. Resection guidance restorations  If intermaxillary fixation is not employed – 2weeks postsurgically, the patient should be placed on an exercise program. Following maximum opening, grasping the chin and moving the mandible away from the surgical side.  These movements tend to loosen scar contracture reduce trismus, and improve maxillomandibular relationships.
  64. 64.  If extensive resection and a considerable period of time has elapsed, guidance procedures are much more difficult and a compromised occlusal relationship may result.  For guidance prosthesis mandibular teeth must be present.  Once an acceptable occlusal relationship is established, the guidance prosthesis may be discarded or used occasionally to reinforce proprioceptive mechanism.
  65. 65. Guidance prosthesis  Robinson and Rubright described Mandibular guidance prosthesis  It consists of a RPD framework with a metal flange extending 7 to 10 mm laterally and superiorly on the buccal aspect of the bicuspids and molars on the nondefect side.  This flange engages the maxillary teeth during mandibular closure.
  66. 66.  If the completed guidance ramp is to be formulated in acrylic resin, autopolymerizing material is added to the prosthesis which is seated in the mouth.  As the resin reaches dough stage, the mandible is manipulated into the desired interocclusal relationship.  The resin should be manipulated to extend 7 to 10 mm superiorly. The prosthesis is removed from the mouth and the resin is allowed to polymerize.
  67. 67.  Palatally based guidance restoration  This is a guidance ramp and an index to a maxillary prosthesis.  Indicated for patients who has severe deviation which prevents manipulation of mandible into any form of acceptable contact.  These maxillary prosthesis are usually constructed of acrylic resin with either cast or wrought wire retainers.
  68. 68.  The full palatal coverage prosthesis is constructed following conventional prosthodontic guidelines.  A mix of autopolymerizing acrylic resin is prepared and added to the palatal prosthesis along the lateral and anterior borders on the nondefect side.  The prosthesis is replaced in the mouth and the mandible is manipulated to the desired position, thus establishing an index in the palate.
  69. 69.  The patient should be able to close into the index with appropriate manual manipulation of the mandible.  When the patient returns, the mandible will usually exhibit more movement laterally toward the non surgical side, requiring adjustment of the palatal ramp. • If and when an acceptable intercuspal position is achieved, a cast mandibular guidance prosthesis may be necessary to maintain mandibular position.
  70. 70. Speech aids and speech therapy  Cantor et al 1969, noted speech improvement by lowering palatal vault prosthetically into the space of Donders to accommodate for restricted tongue movements.  The palate was lowered by means of a retainer for the dentulous patients and by a palatal acrylic resin extension onto the upper denture for edentulous patients. • Misarticulation of speech sounds by mandibular resections.
  71. 71.  Scott 1970, investigated the potential benefit of intensive speech therapy for mandibulectomy patients and concluded that:  Placement of a prosthesis, although improves the quality of specific sounds, does not improve discourse and  Intensive speech therapy improved speech significantly for patients both with and without prosthesis. • Speech therapy is most effective means of improving articulation in mandibulectomy.
  72. 72. Tongue prosthesis  The loss of tongue impairs functions of stomatognathic system.  Moore 1972, suggested that tongue prosthesis provides articulation along with movements of the mandible and cheeks.  Loss of tongue leads to difficulty in controlling saliva and liquids.  Pooling of the fluids in the altered floor of the mouth stimulates cough reflex and/or leading to aspiration.
  73. 73. Prosthetic Rehabilitation of Dentulous Patients
  74. 74. Lateral Discontinuity Defects (Class 2 And 3)  Often resected in the region of 2nd premolar and 1st molar. If there are no other missing teeth in the arch, a prosthesis is usually not indicated.  Framework design should be similar to a Kennedy class 2 design, with extension into the vestibular areas of the resection.
  75. 75.  The forces of occlusion are unilateral and consequently the axis of rotation (fulcrum line) of the partial denture deviates from the norm.
  76. 76.  Major connector – depends on the height of floor of the mouth.  Minor connector – minimize the stress on abutment teeth.  Occlusal rests – near the defect  Retention – use of various types of clasp assemblies on distal abutments.
  77. 77.  If anterior and posterior teeth from resected side missing and posterior teeth on unresected side are missing, prosthesis have 3 denture base regions.  Rests – on as many teeth as possible  Minor connectors – enhance stability and wroght wire retainers are acceptable alternative to bar clasps.  Altered cast impression – used to get max. soft tissue coverage.
  78. 78.  Maxillomandibular records – made with soft wax and minimum occlusal pressure applied.  Acrylic resin teeth  When less than ideal occlusal relationships must be accepted, it may be necessary to establish an occlusal ramp lingual to maxillay teeth on the unresected site.
  79. 79.  Class 3 resection – defect to the midline or farther toward the intact side, leaving half or less of the mandible remaining.  Design of framework – similar to type 2 resection  In this resection – greater chance of prosthesis dislodgement caused by lack of support under anterior extension.
  80. 80. Defects With Mandibular Continuity Anterior Defects (Class 5)  Patients with anterior inner table resections and patients with anterior composite resections in whom mandibular continuity has been reestablished by reconstructive surgery.  These patients display unusual soft tissue configurations and compromised bony support.  Prosthesis for these patients enhance esthetics, speech and control of saliva.
  81. 81.  Indirect retention – long mesial rests on the 2nd Molars  Minor connector – relieve distal aspect and proximal plates  Edentulous areas are recorded with an altered cast impression  Thermoplastic waxes are used to record movable tissue beds.
  82. 82.  Esthetics, occlusion and speech – verify at try-in stage  Prosthesis is delivered with periodic monitoring.
  83. 83. Defects with Mandibular Continuity Lateral Defects (Class 1, 4)  Inferior border of the mandible is intact, and normal movements can be expected.  Compromised denture bearing area – because of closure of the defect using adjacent lining mucosa or presence of split thickness skin graft.  If defect is unilateral and posterior – kennedy class 2 framework design  If marginal resection in anterior area – kennedy class 4 framework design
  84. 84.  Anterior marginal resections some times include part of the anterior tongue and floor of the mouth.  The remaining teeth often collapse lingually and necessitate labial bar as major connector.  Buccal, lingual and labial functional contours – helps in stabilization of the prosthesis.
  85. 85.  Extremely long lever arms & compromised edentulous bearing surfaces contribute to excessive movement of prosthesis during function.  The ‘ribbon rest’ closely parallels the axis of rotation. The anterior and posterior proximal plates move freely during function.  The buccal retainer on the molar and the labial retainer on the cuspid are placed at the height of contour.
  86. 86.  The occlusion should be refined to achieve contact in centric occlusion only and patient should be instructed to masticate on the side of the residual mandibular dentition.
  87. 87. Prosthetic Rehabilitation of Edentulous Patients
  88. 88. Management Of Discontinuity Defects  Complete dentures in these patients are primarily for esthetics.  They improve lip and cheek contour and replace missing teeth.
  89. 89. Factors Determining The Prosthetic Prognosis For Complete Dentures  The prognosis is more favourable if the resection is limited to the cuspid region anteriorly.  If the motor and/or sensory control of the tongue has been significantly compromised by the resection, the prosthetic prognosis becomes extremely guarded.  Severe deviation of the mandible causes instability of the dentures.
  90. 90.  Post surgical lip posture and control, does have important prosthodontics implications.  Due to radiation therapy, there will be reduction in salivary flow which leads to increased risk of mucosal irritation and compromised peripheral seal.
  91. 91. Impression  Primary impression – irreversible hydrocolloid impression material  Final impression – border moulding with modeling plastic and an elastic impression material  Some clinicians advocate making a functional impression of the polished surfaces of mandibular prosthesis
  92. 92. Centric Registration  In maxilla, wax rim used – widened on unresected side in order to account for deviation of the mandible  Determine VDO and VDR  Centric occlusion registration – obtained with wax or plaster  The clinician should manipulate the mandible and place it in the most advantageous position within the reach of the patient.
  93. 93. Occlusal schemes and Lateral registrations  Swoop 1969, suggested “non anatomic teeth” for patients with abnormal jaw relationships and angular path of closure.  “Neutral Zone” identification facilitates positioning of the mandibular teeth.  The wax rim is fabricated according to the neutral zone.
  94. 94.  Special attention should be paid of developing appropriate contours of the rim in contact with the inside of the upper and lower lip.  After the wax rims have been altered and registations obtained, the maxillary and mandibular casts are mounted on a suitable articulator.
  95. 95.  It is advisable to place the maxillary anterior teeth lingual to, and mandibular anterior teeth labial to, their accustomed position.  Lip tooth relationship can be improved if the vertical overlap is increased so that the amount of tooth displayed and the smile line are consistent with a more labial or normal position of the maxillary teeth.
  96. 96.  Generally, in mandible the posterior teeth on the unresected side will be buccal to the crest of edentulous alveolus, especially in the bicuspid region.  The posterior mandibular teeth on the surgical side usually are placed lingual to the crest of the edentulous ridge.
  97. 97.  Contour and support for the corner of the mouth and the lop on the resected side are best accomplished by thickening the denture flange below the crest of the ridge.  After arranging all teeth in the maxillary prosthesis, ramps of 10mm wide and 3-4mm horizontal overlap with the lower teeth should be provided.
  98. 98.  After tooth arrangements have been finalized, the occlusal contact of the mandibular teeth is checked with the maxillary ramp.  The patient should be able to establish contact with ramps without guidance.  After trial prosthesis have been perfected, they are processed following customary procedures.  The use of prosthesis for mastication should be deferred for at least a week. As the patient uses the prosthesis, some adjustment of the ramps usually necessary.
  99. 99. Anterior Border Defects  The prognosis is usually favorable especially if a vestibuloplasty has been completed.  The mandibular movements and maxillomandibular relationships are usually within the normal limits for these patients.  Careful placement of the mandibular anterior teeth and flange contour in this area is suggested.
  100. 100. Review of literature
  101. 101.  They supported this concept by quoting Fish (1933) who gave this concept, and stressed on the importance of polished surface for the retention and stability of the denture. Shifman and Lepley(1982): Neutral zone or ‘denture space’ concept for marginal mandibulectomy patients.
  102. 102.  In this method short and narrow artificial teeth which will not interfere with the denture space were selected.  They were arranged on the diagnostic cast; occlusion and esthetics were verified clinically. This was done in self-cure acrylic resin and space was present underneath the occlusion for impression material. This prosthesis was retained by simple Adams or embrasure claps.
  103. 103.  A functional impression of the defect side is made using modelling compound for muscle trimming and is completed with an impression wax.  The released prosthesis is than cured and finished in the usual manner.
  104. 104. Cantor and Curtis(1971): Swallowing technique in edentulous patient  A preliminary alginate impression of the mandibular fragment is made in a modified stock tray.  A narrow area, supported by bone and free of any muscular activity, is drawn on the diagnostic cast and a perforated acrylic resin custom tray is constructed that conforms to this area.  Two lateral columns that extend toward the maxillary ridge are formed on the tray.
  105. 105.  Modeling compound “stops” are placed under the column tray for stability and to provide space for the impression material.  Modeling compound is then added to the lateral columns extending them superiorly until firm bilateral contact is made with the maxilllary residual alveolar ridge.  The vertical height of the columns should exceed the postsurgical physiologic rest position by at least 2 to 3 mm.
  106. 106.  The lower part of the oral cavity is filled with an alginate impression material that has been mixed with approximately one third more water than is recommended by the manufacture.  The column tray is placed through the hydrocollooid material until it is seated firmly on the alveolar mucosa.
  107. 107.  The mandible is then closed until the maxillary ridge rests are properly seated, and the custom tray is securely in place with the tongue resting between the columns on the tray.  At this point, the patient begins to swallow, and between each swallowing cycle, he puckers his lips.  The patient continues these two motions until the alginate material has set.
  108. 108. Swatantra agarwal, Praveen G, Samarth Kumar agarwal and Sankalp sharma (2011), suggested Twin Occlusion in which they did functional rehabilitation of hemimandibulectomy patient, who had undergone resection without reconstruction.
  109. 109. Maxillary arch representing kennedy’s class I Bite record
  110. 110. OPG reveals resection of mandible of left side Intercuspation obtained by twin occlusion on nonresected side
  111. 111. Mounted cast on articulator with arrangement of teeth Occlusal view of definitive prosthesis placed in maxilla
  112. 112. Summary & Conclusion
  113. 113.  Management of mandibular defects is one of the most challenging aspects of maxillo-facial prosthetics. These defects affect not only function but also appearance and thus the prosthodontists has to fulfill the dual responsibility of restoring function and appearance.  With the advent of advanced surgical and bone grafting techniques, satisfactory prosthodontic prognosis can be achieved for such patients. However there are still some inherent problems in these procedures which have not been completely overcome.
  114. 114.  On his part the prosthodontists should be able to efficiently plane and execute treatment because the scope of patients with mandibular defects may vary form the completely edentulous patient to the patient with few teeth remaining or patients requiring implant supported prosthesis.
  115. 115. References  John Beumer, Maxillofacial rehabilitation prosthodontic and surgical reconstruction, 1st edition 1979  Taylor TD, Clinical maxillofacial prosthetics, 1st edition 2000.  William R Laney, Maxillofacial prosthetics, postgraduate dental hand book series, Vol 4.  Kenneth L Stewart, Clinical removable partial prosthodontics, 2nd edition.  Osbon DB. Early treatment of soft tissue injuries of the face. J Oral Surg 1969;27:480–7.
  116. 116.  Cantor R and Curtis TA Prosthetic management of edentulous mandibulectomy patients - Part 1. J Prosthet Dent, 1971; 25:447-455.  Cantor R and Curtis TA Prosthetic management of edentulous mandibulectomy patients - Part 2- J Prosthet Dent, 1971;25:547-555.  Cantor R and Curtis TA Prosthetic management of edentulous mandibulectomy patients - Part 3- J Prosthet Dent, 1971;25:671-678.  Shifman A and Lepley JB Prosthodontic management of postsurgical soft tissue deformities associated with marginal mandibulectomies. J Prosthet Dent, 1982; 48:178-183.  Swoope CC Prosthetic management of resected edentulous mandibles. J Prosthet Dent, 1969; 21:197-201.
  117. 117.  Desjardins RP Occlusal considerations in partial mandibulectomy patients . J Prosthet Dent, 1979; 41:308-311.  Kelly EK Partial denture design applicable to the maxillofacial patient. J Prosthet Dent, 1965; 15:168-173.  Ackerman AJ The prosthodontic management of oral and facial defects J Prosthet Dent, 1955; 5:413-432.  Aramany MA and Myers EN Intermaxillary fixation following mandibular resection. J Prosthet Dent, 1977; 37:437-443.  Maxillofacial rehabilitation prosthodontic and surgical considerations, John Beumer, Thomas A. Curtis & David N. Firtell; 1st edition 1979
  118. 118.  Scannell JB Practical considerations in dental treatment of patients with head and neck cancer. J Prosthet Dent, 1965; 15:764-778.  Schaff NG Oral reconstruction for edentulous patients after partial mandibulectomies. J Prosthet Dent, 1976; 36:292-297.

×