Prosthodontic rehabilitation of mandibulectomy

Prosthodontic Rehabilitation Of Mandibulectomy Patients

Vinay Pavan Kumar K2nd year P G student

Dept of ProsthodonticsAECS Maaruti College of Dental Sciences

Classification of defects

Treatment

Surgical

Prosthodontic

Partially edentulous

Completely edentulous

Rehabilitation of mandibulectomy

patients

Diagnostic considerations

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

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

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

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

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

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.

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.

Goals of Mandibular Reconstruction

Restore form and function

• Restore bony contour of native mandible

• Restoration of mastication

Deglutition Articulation Maintainance of the airway

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

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

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

Presence of remaining teeth

Determines the prognosis of rehabilitative therapy

Presence of teeth – better retention, stability and support

Mandibular incisors – abutments – indirect retention

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

Treatment for mandibular rotation and deviation

Restoration of continuity by osseous grafting

Physical therapy – stretching exercises, reposition training

Mandibular resection guidance prosthesis

- mandibular guide flange

- maxillary guidance ramp

Maxillary palatally positioned guidance ramp

When deviation is less severe

Not indicated in edentulous patients – lateral forces on complete dentures cannot be taken up

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

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

Compromise of vestibular extensions

Implant rehabilitation

Grafted bone limited- length, diameter and number of implants less than ideal

Bone plates and screws to be removed

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

Surgical reconstruction

Alloplastic implants

Vascularized free tissue grafts Fibular Free Flap Scapular Free Flap Iliac Crest Free Flap Radial Forearm Free Flap Double Flap Reconstruction

Prosthodontic rehabilitation of partially edentulous patients

Lateral discontinuity defects Lateral defects with anterior teeth present Arc of closure – angular

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

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

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

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

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

Lateral defects

Posterior dentition remains on only one side of the arch

Conventional partial denture

Implant retained

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

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

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

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

Processing, delivery and follow up

Patients monitored closely during post insertion period

Use of prosthesis for mastication deferred for a week

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

Avinash C K A et al, Prosthetic management of partially resected dentulous mandible, Indian J Dent Adv 2011; 3 (1): 750-753

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

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.