Removal partial denture considerations in maxillofacial

prosthetics. (Part -1)

theoptimalsmile.wix.com

Index

1. Maxilofacial prosthetics

Definition

Classification

2. Timing of dental and maxillofacial prosthetic care for acquired defects

Post operative and intraoperative care

Interim care

Potential complications

Defect and oral hygiene

Definitive care

Index

3. Intraoral prostheses design considerations.

4. Surgical preservation for prostheses benefit

Maxillary defects

Mandibular defects

Mandibular reconstruction-bone grafts

Maxillofacial Prosthetics

• “the art and science of anatomic, functional, or cosmetic reconstruction by means of nonliving substitutes of those regions in the maxilla, mandible, and face that are missing or defective because of surgical intervention, trauma, pathology, or developmental or congenital malformations”

Classification

• Acquired • Congenital• Developmental• Acquired defect – trauma or disease-RX

Soft/hardpalate defect-squamous cell carcinoma.• Congenital defect – craniofacial defects - birth.• Developmental defect – genetic predisposition-

growth and development.

Classification

Type of prostheisis under consideration-

• Extra-oral (cranial or facial replacement)• Intra-oral (oral cavity)• Interim (short periods)• Definitive (more permanent)• Treatment prosthesis (splint or stent)

• Major distinguishing feature-tooth supported or tooth and tissue supported.

• Maxillofacial patient can experience unique alterations in normal oral/craniofacial environment which are the results of surgical resections.

• (maxillofacial trauma,congenital defects,developmental anomalies or neuromuscular disease.)

• Not only tooth and tissue support considerations-design.

Timing of dental and maxillofacial prosthetic care for acquired

defects

• Preoperative and intrao-perative care

• Interim care

• Definitive care

Preoperative and intraoperative care

• Planning of prosthetic treatment for acquired oral defects-before surgery.

• Pt-head and neck surgery-dental needs.

• Dental objectives-preoperative and intraoperative care stage-potential dental postoperative complications-subsequent prosthetic Rx.

Preoperative and intraoperative care

• Preoperative consultation-pt clinician relationship-surgery.

• Benefit from a prosthesis standpoint view-strategically important teeth-interim or definitive prosthesis use-discussed surigical team-rx plan –preservation.

Preoperative and intraoperative care

• Immediate postoperative period-challenging.

• Large carious lesion-endodontic therapy.

• Acute periodontal disease – treated-post pain.

• Nonrestorable tooth-interim care-removed-before/at time of surgical resection.

Preoperative and intraoperative care

• Impressions –max and mand arches-immediate or interim prostheses.

• To assess need for both immediate and delayed modification of teeth or adjacent structures to optimize prosthetic care.

• Planning-definitive prosthesis.

Interim care

• Major empahasis-surgical mangement need of pt.

• When discontinuity defects in mandible results-interim prosthetic care-not indicated.

• Typical maxillary acquired defect results in oral communication with the nose/max sinus.

Interim care

• Creates physiological and functional deficiencies in mastication,degluttition and speech.

• Such defects-psychological.

• Major deficiency addressed by prosthetic management-interim care time-degluttition and speech.

Interim care

• An initial focus on improvement in swallowing and speech with the interim prosthesis can help boost the rehabilitation process significantly.

• Objective of interim obturator prosthesis-separate-oral and nasal cavities-obturating communication.

• Such obturator prostheis commonly refers – obturation of hard palatal defects-same for soft palate.

Interim care

• To artificially block free transfer of speech sounds and food/liquids b/w oral and nasal cavities.

• Prosthesis-surgery.

• Surgical obturator prostheis-control-surgical access closure and split thickness skin graft-postsurgical period.

Interim care

• Such prostheis-stabilized-wiring-teeth-alveolar bone.

• Teeth-wires in prostheis-undercuts

• Immediate placement of prostheis-pts acceptance of surgical defect.

Interim care

• Preferable-stabilize surgical dressing-suturing sponge bolster-split thickness graft.

• Following primary healing-interim prostheis placed.

Interim care

• Interim prostheis-wire retained resin prosthesis-no teeth-modified-addition of teeth.

Interim care

• Total maxillectomy-prosthesis support stability and retention –not satisfactory-extension of defect.

• Teeth present-impact of defect lessened.

• Few unilateral teeth-stability-prosthesis is less.

Potential complications

• Duration for interim phase-3-4 months.• Primary objective-surgical-observation phase.

Common interim prosthetic complications :-

• Tissue trauma and associated discomfort.• Inadequate retention of max prostheisis.• Incomlete obturation with leakage of air,food and

liquid around obturator portion-prostheis.• Tissue effects of chemotherapy and radiation

therapy.

Potential complications

Common interim prosthetic complications :-

• Tissue trauma and associated discomfort.

• Inadequate retention.

• Incomplete obturation (leakage of air,food and liquid).

• Tissue effects of chemotherapy&radiation therapy.

Discomfort related to use of interim prosthesis-

• Surgical wound healing dynamics.• Defect conditions.• Mucosal effects of adjunctive Rx/prosthetic fit.• Common areas of surgical wound pain include

junctions of lip/cheek mucosa-maxillectomy pts.

• Lateral scar band-skin grafts heals-discomfort.• Alveolar bone cuts not rounded-perforate-oral

mucosa-discomfort.• Most common in mandibular resection-lower

and labial contour.

Potential complications

• Prosthesis movt-dependent on quality of supporting structures.

• When teeth present-retention-clasps.

• For edentulous pts-denture adhesives.

Potential complications

• When max resection leaves cheek unsupported by bone-prosthesis-support-wound maturation.

• During immediate postoperative healing stage-surgical defect-change in dimension-fit and seal.

• Adjustments-temporary resilient denture lining materials.

• Pts instructed not to swallow large quantities-head horizontal-swallowing-water tight seal.

Potential complications

• Midline soft palate resection-difficult-retain prostheis-water tight seal.

• When combination Rx (chemotherapy,physiotherapy) – post surgical phase.

• Major intraoral complication-mucositis.

• Long term effects of radiation therapy-radiation induced xerostomia and capillary bed changes-within mandible-dentition-osteoradionecrosis.

• During interim prosthesis stage-xerostomic effects.

Defect and oral hygiene

• Surgical pack removal-defect site mature with time.

• Initial loss of incompletely consolidated skin graft,mucous secretions mixed with blood and residual food debris –common.

• Pts instructed to clean defect of food debris and mucous secretions routinely.

Defect and oral hygiene

• Defect hygiene-timelier healing-improve-fit of prosthesis.

• Common defect hygiene practices-rinsing of defect-bulb syringe,sponge handled cleaning aid.

• Teeth-oral hygiene.

• Xerostomia-fluoride.

Definitive care

• Initiated-completion of active Rx phase-defect tissue matured sufficiently-to tolerate aggressive manipulation and obturation.

• Primary emphasis-prosthetic management.

• Design of prostheis differ-interim prosthesis.

Definitive care

• For some pts definitive prostheis delayed-general health concerns,questionable tumor prognosis and improper hygiene.

• For control of maxillofacial prostheses-large skilled performance of pt required.(oral and defect structures important for success.)

Definitive care

• Understanding of impact of post surgical characteristics and soft tissue reconstruction on MFPmanagement :-

• Opportunity for max prosthetic benefit-necessitates surgical site characterestics that are separate from classic tumor approaches.

• Ability of pt to biomechanically control large removable prostheis following surgery-hindered-surgical closure/reconstruction options.

Intraoral prostheses design considerations

• For maxilofacial reconstruction with RPD-well supported stable,retentive prosthesis-min movt-preserving-max amt-supporting tissue.

• Max coverage-edentulous ridge-remaining teeth.

• Normal resistance-functional load-P.attachment-natural dentition.

• Partial edentulous-support,stability-teeth.

Intraoral prostheses design considerations

• Several post teeth-support-teeth and mucosa.

• No teeth-support-mucosa-residual ridges.

• Tumor-loss-tooth & supporting structures-support-combination-teeth/ridge.

• For both partial & complete tissue supported-functional load support-mucosa-unsuited.

Surgical preservation for prosthesis benefit

Maxillary defects –

• Surgical outcomes that impact prosthetic success-amt of max structures removed/that impacts the surgical integrity and quality of the defect.

• For hard/soft palate-restoration of physical separation of oral and nasal cavities-mastication ,deglutition,speech & facial contour.

Surgical preservation for prosthesis benefit

• Typical prostheis-obturator prostheisis,speech aid prosthesis.

• Obturator prosthesis-that restore palatopharyngeal function for defects of the soft palate.

• Speech prostheis-palatopharyngeal function.-soft palate.

Surgical preservation for prosthesis benefit

• Tooth preservation-greatest impact-stabilizing effect.

• Classical midline max defect-preservation of premax accomplished-inclusion of ant premaxilla-individual decision-tumor control and resection technique.

• Resection of pt with teeth-tooth adjacent to defect-force-prostheis movt.

• Surgical alveolar osteotomy cut-resection-xn site –adjacent tooth-prognosis-supportive tooth.

Surgical preservation for prosthesis benefit

• Midline of hard palate-common-prosthesis pressure.

• To provide best surgical resection-hard palate resected.

• Vertical surface of bone cut-advancement flap-palatal mucosa-resilient mucosal covering-prostheis-fulcrum.

Surgical preservation for prosthesis benefit

• To serve as a guide-decision-surgery-if resection leaves less than 1/3rd of soft palate-entire palate removed.

• Exception-edentulous pt-radical maxillectomy.

• Without teeth to provide retention-pt benefits-prostheis-above posterior soft tissue band-retention.

Surgical preservation for prosthesis benefit

• Preparation of max surgical site-split thickness graft.

• If pterygoid plate,ant temporal bone-support-skin graft.

• Extension into defect-greater-edentulous-than pt-teeth.

• However all pts-lateral-post region-seal defect.

Surgical preservation for prosthesis benefit

• Surgical defects 3cm or less-reconstructed to normal contours-tissue function-surgical management-appropriate.

• Larger defects-difficult-incapable-prostheis.

• Soft palate reconstructions-difficult-functional tissue replacement-compromising-palatal function.

• In light of this unpredicability,the predictable prosthetic management of such defects is most often the Rx of choice.

Mandibular defects

Functions of mastication,deglutition,speech and saliva control are possible through coordinated efforts of separate anatomic regions which include:-

• Oral sphincter.• Alveolingual and buccal sulci.• Alveolar ridges,floor of mouth.• Tongue,tonsillar pillars.• Soft palate,hard palate.• Buccal mucosa.• More regions involved-surgical procedure-greater

demand –surgical reconstruction.

Mandibular defects• When mand involved-complexity-reconstruction-

location and amt of mand -resection.• Primary prosthetic objectives-restore mastication and

cosmesis-replacement-teeth.

• Regardless of prostheis support-prosthetic success-surgical management-soft tissue,bone.

• Diseases-soft tissue structures-resection-control.

• Soft tissue-bone removal-no prosthetic management.

• Exception-tongue resection-augmentation-palatal contours-speech production.

• Primary tumors-ameloblastoma-resection of segments-tumor control.

Mandibular defects• Common mand resection-lateral,ant,hemimandibular.

Debilitating defects:-

• Cosmetic deformity-lower third of face,• Dec masticatory function,• Compromised coordination of tongue and teeth,• Altered speech ability, impaired degluttition.

Mandibular defects• Masticatory rehabilitation-resection-with mand

discontinuity-unpredictable.

• For pts with teeth-altered mand position-functional and cosmetic handicap.

• Reconstruction plate failure.

• Cosmetic deformity improved-reconstruction plates.

• Preserves bilateral nature of mand movt.

• Prosthetic replacement of teeth-cannot-regions superior-recontruction bar-mucosal perforation,bar exposure.

Mandibular reconstruction-Bone grafts

• Ideal prosthetic characteristics of replacement mandible-stable union-proximal&distal segments, restoration of contour to lower 3rd of face,rounded ridge contour-attached mucosa 2-3mm.

• Regardless–prosthesis-bone-vital-functional use.

• For optimal chance of prosthetic function-implants.

Mandibular reconstruction-Bone grafts

• Major determining factor-soft tissue reconstruction.

• Major complication-bulk of soft tissue-lack of tongue mobility.

• Another complication-bone placement and size.

• Fibula–mand replacement.

Mandibular reconstruction-Bone grafts

• Bcos of straight nature of bone it is easy to err in both the horizontal and vertical positioning-midline.

• Post inability to recreate natural ascending curve posteriorly-teeth-restoring occlusion-resected side.

• Mismatch-height-ant junction of graft.

• Implant supported prosthesis-implant hygiene.

• For removable prostheses-irritation-fulcrum like action-movt.

References

Carr A B, Mc Givney G P, Brown D T, McCraken’s Removable partial Prothodontics. 11th ed, st louis: Mosby; 2008.

Stewart K L, Rudd K D, Kuebker W A, Stewart’s Clinical Removable Partial Prosthodontics. 2nd edition 2004.

Miller E L, Grasso J E, Removable Partial Prosthodontics. 2nd ed, Baltimore: Williams & Wilkins.