Maxillofacial Prosthetics - Restoration of Soft Palate Defects

A properly designed and extended obturator prosthesis for a soft palate defect should provide the patient with perfect speech if a segment of the velopharyngeal musculature remains.  This program describes and illustrates in detail the methods used in fabricating these prostheses for soft palate defects.

Maxillofacial Prosthetics – Restoration of Soft Palate Defects — Course Transcript

• 1. 20. Restoration of Soft Palate Defects John Beumer III, DDS, MS*The material in this program of instruction is protected by copyright ©. Nopart of this program of instruction may be reproduced, recorded, ortransmitted by any means, electronic,digital, photographic, mechanical etc.or by any information storage or retrieval system, without prior permission.
• 2. Etiology of Soft Palate Defectsv Resection of tumors of the soft palatev Cleftsv Chemo-radiation
• 3. Prosthetic Restoration of Soft Palate Defects
• 4. RPD FrameworksImpressions:Irreversible hydrocolloid with a stock trayExtend tray and impression into the defect • Attempt to record as much of the defect as is reasonable with this impression. • This will greatly facilitate the fabrication of the altered cast tray extension.
• 5. RPD Frameworks RPD Designs Unique features: a) Forces of gravity b) Long lever arms c) Retentive loop must extend into the defectThe effect of the obturator extension will bemost significant for patients with KennedyClass I or Class II partial dentures.Indirect retention is key to counteracting thelong lever arms and the forces of gravity.
• 6. Altered cast impression trays Characteristics: Made of tray resin for easy adjustability during molding of the obturator. There should be 2-3 mm of space between the tray extension and adjacent tissues at maximum contracture of the residual velopharyngeal musculature. Disclosing wax is useful in checking tray extension.
• 7. Border Molding the Obturator The defect is functionally molded with a low fusing dental compound and refined with a thermoplastic wax.Maneuvers used to trim the bulb • Flexure of the neck combined with rotation of the head • Speech – primarily plosive sounds • Swallowing
• 8. Border Molding the ObturatorDry swallowing results in a more forcefulcontraction of the velopharyngeal musculatureand should not be used to refine the bulb. Otherwise the bulb will be underextended.
• 9. Border Molding the ObturatorThe obturator must enable the patient to develop sufficient oralpressure for the oral components of speech and resonance. However, balance between oral and nasal resonance must be achieved if normal speech is to be achieved. Adequate nasal airway is necessary for nasal phonemes,
• 10. Border Molding the Obturator Begin by adding compound to the anterior portion of the defect before progressing to the lateral and posterior areas. The activated pharyngeal musculature will displace the excess compound superiorly and inferiorly.Compound that extends above or below the area of the velopharyngealmechanism should be trimmed away. The oral side of the obturator must beconcave and the nasal side should be convex.
• 11. Border Molding the ObturatorThe range of movement represents the potential spacebetween the obturator and the adjacent tissues at rest. Ifthese tissues are immobile or if the obturator extends abovethe area of movement, the prosthesis has the potential tocompromise the patency of the nasal airway . In such circumstances speech cannot be restored to normal. At best a balance between hypernasality and hyponasality is achieved.
• 12. Compound cutback The compound is cut back 1-2 mm prior to adding the thermoplastic wax. Iowa wax is added to the surface of the compound The wax is tempered and placed intraorallyThe pattern is moldedfunctionally by having thepatient speak and swallowas previously.
• 13. Corrected Impression Border molding is completed by having theA patient wear the wax- compound obturator for at least two hours in order to ensure that the impression is not overextended. Note that in (A) the velopharyngeal musculature is in full contracture while in (B) it isB
• 14. Completed impressionsCharacteristics of a good impression 10-15 mm
• 15. Soft Palate Obturators Completed impressions Characteristics of a good impression 10-15 mm Wax pattern in passive contact with the velopharyngeal complex during functional contraction. No compound is exposed. Concave tongue surface Convex nasal surface Wax pattern does not extend beyond the zone of function. In most patients the height of the pharyngeal extension does not exceed 10-15mm
• 16. Correcting impressions Note the exposure of compound in this impression. This area of the impression is overextended and must be remolded.This region was cut backand remolded with Completed impressionthermoplastic wax.
• 17. The impression is boxed in the usual manner
• 18. ProcessingAltered cast The obturator portion of the cast is filled with wax before flasking.
• 19. ProcessingClear heat cure acrylic resin is preferred.
• 20. Delivery Extensions are verified with: a) Pressure indicating paste b) Disclosing wax
• 21. Soft Palate Obturators Completed Obturator • Oral side is concave • Nasal side is convex • All surfaces are highly polished
• 22. Soft Palate Obturators DeliveryAt rest, there is space around During contraction thethe obturator. This allows for obturator comes in contactthe production of nasal sounds with the velopharyngealand permits nasal breathing. musculature and enables the production of normal oral sounds and swallowing.
• 23. Obturator reduction and compensatory movement Some clinicians have reported increasedlateral wall movement following reduction ofthe obturator prosthesis to the point insome patients where the prosthesis couldbe removed altogether (Weis CE, 1971).These results have been questioned and have not beenreproduced by others. We have observed changes inobturator size and shape during years of use but not tothe point where it was possible to remove the applianceand maintain velopharyngeal closure.
• 24. Obturator reduction and compensatory movement 1988 1995l Both obturators were made for the same patient, but 7 years apart. Note that the lateral wall extension of the prosthesis on the left (arrows) is greater than that on the right.
• 25. The oral surfaces of the obturator prosthesis must be concave This obturator prosthesis was made for a patient with a partially repaired cleft lip and palate. Note the concave oral surface. Flat or convex oral surfaces may cause gagging or difficulty during swallowing
• 26. Oral surface must be concaveThe oral surface of the initial prosthesis was convex and activated thegag reflex. The remade prosthesis eliminated this problem.Convex surfaces precipitate gagging and mayinterfere with the oral phase of swallowing.
• 27. Implant retained soft palate obturators In edentulous patients, the effectiveness of an obturator restoring V-P function is dramatically improved.Why? Retention Precision of placement of the obturator prosthesis
• 28. Patient is status post partial palatectomy. In addition, about two thirds ofthe soft palate had been removed. The defect was not lined with skin andprovided no retentive undercuts. Note the torus tubarius (arrow). A lateral cephalometric x- ray indicated sufficient bone for placement of several implants in the premaxilla. Only four of the six were uncovered.Denture adhesive was used toretain the complete denture andobturator
• 29. Four implants of the six were uncovered and a bar fabricated. The maxillary molar was retained and used for posterior support. Note that most of the palatal shelf has been retained. An implant support tissue bar wasAn impression tray withretentive clips is fabricated inpreparation for an altered castimpression of the defect.
• 30. The retention provided by the barenables the making of accuratealtered cast impressions. Thevelopharyngeal area was bordermolded with dental compound andcorrected with a thermoplastic wax.
• 31. The completed altered cast impression
• 32. v Face bow and centric records were made and transferred to the articulator is the usual fashion. vThe completed complete denture and obturator vThe completed prosthesis in position. It made a dramatic impact on the patient’s psychologic outlook. Retention was excellent and speech, mastication, and swallowing were restored.
• 33. Tissue bar designs – Four ImplantsImplant assisted designs are recommended to minimize the risk of implant overload.
• 34. UCLA Design v Anterior – Posterior spread should be maximized v The anterior two implants should be 12-20 mm apart A-P spreadERA attachments are positioned adjacent to the distal implants.This attachment permits the overlay prosthesis to be compressedinto the mucoperiosteum in the extension areas still present. As aresult, the denture bearing tissues absorb the occlusal forces.
• 35. Soft palate defects secondary to tumor resectionsAlterations at surgical resection toenhance the prosthetic prognosisv Ifthe resection extend posteriorly to include the middle third of the soft palate (the area occupied by the levator), the resection should be extended to include the remaining posterior third.v The residual portion of soft palate should not be tethered to a flap. Otherwise, access to the residual velopharyngeal musculature may be impaired.
• 36. a b a: Squamous carcinoma of tonsil. b: Low grade mucoepidermoid of the soft palate. In both patients significant portions of soft palate were removed.
• 37. Alterations at surgeryThe residual soft palate is tethered to the lateralpharyngeal wall. The prognosis for the obturatorprosthesis is guarded because: vThe movement of the residual V-P mechanism is impaired. vAccess to the defect is difficult.
• 38. Alterations at surgery to improve the prosthetic prognosis Examples of inappropriate attempts to reconstruct the soft palate
• 39. Surgical modifications (cont’d) Soft palate resectionThe posterior one third of the soft palate was retained in boththese patients. This strip of mucosa is nonfunctional and preventsproper extension of an obturator prosthesis into the residualvelopharyngeal mechanism that is still functional.Result: Speech will be hypernasal.
• 40. Alterations at surgery to improve the prosthetic prognosisa bKey factor – Access to the residual V-P musculature a: Soft palate defect. Lateral wall of pharynx has been resurfaced with lateral forearm flap. b: Obturator prosthesis extends around and behind the residual soft palate to engage still functional right pharyngeal wall and residual portion of soft palate. V-P function was restored to normal
• 41. Ideal Soft Palate DefectsThe soft palate is not tethered to a flap or the lateralpharyngeal wall. Therefore: Its movement will not be impeded during V-P function. Access to the area of V-P movement is not impaired Result: Normal speech and swallowing can be predictably restored.
• 42. Tonsillar defects that extend onto the soft palate Use of free vascularized flapsShould the flap be tied to the residual soft palate? v If more than half of the levator palatini is resected (ie, if the resection crosses the midline) the flap should not be connected to the residual portion of the soft palate. Such a defect is best restored with an obturator prosthesis v If less than the above is resected the flap can be connected to the soft palate with a reasonable expectation that the residual levator will be able to pull the flap into such a position so as to achieve velopharyngeal closure.
• 43. Surgical reconstruction of the soft palateThis resection falls short of the uvula. The soft palate defectwas effectively reconstructed with a free flap.If the resection extends across the midline the defect shouldbe restored with an obturator prosthesis.
• 44. This resection extended beyond midline. The flap used to reconstruct the defect was tied to the residual soft palate., The mass of the residual levator veli palatini is insufficient to elevate the soft palate superiorly and posteriorly to achieve velopharyngeal closure.Effective obturation is difficult because of limitedaccess to the residual velopharyngeal complex.
• 45. 1 week postoperative Surgical Modifications v This flap was not tied to the soft palate. Easy access to the velopharyngeal defect makes obturation4 months postoperative easy and predictable.
• 46. Surgical Modifications vAll of the below represent ill conceived attempts to reconstruct the soft palate. Result: Patients with V-P insufficiency but which cannot be effectively obturated prosthetically.
• 47. Myocutaneous flaps A PMC flap was used to restore this tonsillar defect.The soft palate was nottethered to the flap.Therefore access to theresidual V-P area isensured and V-Pfunction is easilyrestored with anobturator (arrow).
• 48. Surgical Obturators – Soft Palate Tumors The cast is altered. The surgeon plans to remove the entire soft palate and the right posterior alveolar ridge and hard palate.Adenoid cystic carcinomaof the junction of hardand soft palate
• 49. Surgical Obturators – Soft Palate Tumors Note the reduction in the soft palate area (arrows). The cast should be adjusted in order to develop the soft palate extension along the palatal plane.
• 50. Surgical Obturators Soft Palate Tumors Following resection the obturator portion is relined with a temporary denture reliner.
• 51. Delayed Surgical Obturationv Recommended for lateral defects of the soft palatev Impressions are made after surgeryv At delivery the obturator extension
• 52. Delayed surgical obturationa c b a: Soft palate defect secondary to surgical resection. b: Obturator extension has been developed with a temporary denture reliner that can adjusted and polished. This prosthesis can serve as interim obturator. c: Prosthesis in position.
• 53. Interim obturators.The obturator extension is border molded with atemporary denture reliner (Rim Seal). We favor RimSeal because it is quite moldable and can be polished.
• 54. Posterior Border Defects In these defects the obturator extends up and behind the residual soft palate.Velopharyngeal closure is obtained by engagingthe remnants of the levator veli palatini in lateralpharyngeal walls with the obturator.
• 55. RPD framework. Note that the retention loop for the obturator does not extend into the defect. This is a mistake commonly made by dental labs. It can be corrected following the molding of the obturator extension.v Initial molding is made with modeling compound.
• 56. Border molding is completevThe initial molding isaccomplished with modelingcompound.vThe compound is cut back 1-2mm before addition of thethermoplastic wax.
• 57. v The pattern is refined with a thermoplastic wax (Iowa wax)v The excess (arrows) wax trimmed away and the patient is asked to wear the pattern for another 90 minutes to complete the impression.
• 58. The completed pattern is boxed in the
• 59. A new retention loop that extends into the
• 60. Completed prosthesis • It is delivered in the usual fashion using pressure indicating paste (PIP) and disclosing wax.
• 61. Completed prosthesis in positionv During V-P closure the lateral extension of the obturator engages the lateral pharyngeal walls.v At rest there is space between the obturator and the lateral walls permitting nasal breathing and normal nasal resonanceThe oral side of theobturator is concave.Obturators that aretoo low cause thepatient to gag duringswallowing.
• 62. Lateral border defectsa b c d e f g h a: RPD framework. b, c, d, e and f: Interim obturator seated on master cast and with silicone putty and used to make initial obturator extension. g and h: Final border molding of obturator prosthesis. i: Completed prosthesis in position
• 63. Prognosis for normal V-P function with and obturator prosthesis Access to the defect – Can you engage the active V-P areas? If you cannot engage these areas the prognosis is poor Residual movement of the residual velopharyngeal mechanism. In the absence of movement, speech cannot be restored to normal.
• 64. What is the prognosis for V-P function in this patient?Excellent: v Good access to the active V-P areas v Excellent movement of the V-P complex v Excellent retention available for the prosthesis
• 65. What is the prognosis for V-PExcellent: Good access Excellent movement of the V-P complex Excellent retention for the prosthesis
• 66. Prognosis for V-P function?The patient is S/P resection of the right tonsil and softpalate for a squamous carcinoma. The patient receiveda course of postoperative radiation therapy. The tongue was not affected by the resection. The premaxilla was not in the field of radiation.
• 67. Prognosis for V-P function?Good Excellent movement of the left pharyngeal wall Good access to the left lateral wall of the defect Retention suboptimal for the prosthesis (the patient was irradiated and the posterior palatal seal area had been altered by the resection).Retention can be significantly improved with the use ofosseointegrated implants changing the prognosis to excellent.
• 68. Prognosis for normal speech? Patient is S/P resection of the entire soft palate and the posterior portion of the hard palate for a large pleomorphic adenomaClinical exam Little or no movement of the residual velopharyngeal mechanism Little means of retention Little support and stability
• 69. Prognosis for normal speechChallenge:a) Develop a secure means of retention so as to maximize the efficiency of the obturatorb) Restore speech to normalSolution:a) Placement of osseointegrated implants in the premaxillab) Reduce the lateral extension of the obturator so as to allow for nasal airway and reasonable nasal resonance without making the speech excessively hypernasal
• 70. Prognosis for normal speech Will the speech be restored to normal in this patient with the obturator prosthesis? No!!! Why not?In a patient with little or nomovement of the residualvelopharyngeal mechanism anda properly extended obturator,speech will be slightlyhypernasal during theproduction of oral sounds andslightly hyponasal during theproduction of nasal sounds.
• 71. Prognosis for Normal Speech Patient is S/P resection of the lateral third of the soft palate for a recurrent squamous cell carcinoma. She has received 6600 cGy via opposed lateral facial fields.Clinical exam:a) Residual soft palate and the left pharyngeal wall moves wellb) Retention will be compromised because patient is edentulousc) Stability and support are adequate for the maxillary complete denture
• 72. Prognosis for Normal SpeechChallenge: a) Develop a secure means of retention for the complete denture and obturator b) Restore speech to normalSolution:a) Place osseointegrated implants into the premaxilla (this area was out of the field of radiation).b) Develop the contours and extensions of the obturator in a normal fashion.
• 73. Prognosis for Normal Speechl Will the patient’s speech be restored to normal with the complete denture and obturator prosthesis? Why in this patient and not in the previous. Yes!! patient? a) Excellent movement of the residual V-P mechanism b) Excellent access to the area of residual V-P mechanism
• 74. Prognosis for V-P functionPatient is S/P resection of a squamous carcinoma ofthe tonsil extending onto the soft palate. The right baseof the tongue was included in the resection along withhypoglossal and lingual nerves on that side.
• 75. Prognosis for V-P functionExcellent: •Fair access to the left lateral wall of the defect •Excellent movement of the left lateral pharyngeal wall •Good retention for the prosthesis (post-palatal seal area was not affected by the surgical resection and the patient was not irradiated postoperatively).
• 76. Prognosis for V-P functionThe quality of speech articulation, however was only fairbecause of the loss of the base of the tongue and the lossof motor and sensory innervation of tongue on the resectedside.
• 77. Prognosis for V-P functionA small tongue flap was used to resurface the tonsillar area.The mobility of the tongue was only slightly affected. The softpalate elevates but does not achieve closure. Access to thedefect is difficult. Sufficient dentition is available for retention.
• 78. Prognosis for V-P functionAlthough access is limited appropriate contours of theobturator can be developed that will enable the patient toachieve velopharyngeal closure. Prognosis is good.
• 79. a Junction hard palate – soft palate defects a b c a: Schematic drawing of movement of anterior margin of soft palate during palatal elevation. b: Patient with defect of hard and soft palates, with soft palate at rest. c: Same patient during elevation. Contact should be maintained between soft palate and obturator during elevation to minimize leakage.
• 80. Junction hard palate – soft palate defects To maintain seal, an extension (arrow) must be developed which engages the nasal side of the soft palate when the soft palate elevates.
• 81. Junction hard-soft palate defectsThe soft palate posterior to the defect did not elevate sufficientlyto achieve V-P closure and so the obturator was extendedthrough the defect to engage the lateral pharyngeal wall.Fortunately, the defect was wide enough to permit thisextension.
• 82. Junction hard-soft palate defectsSpeech was restored to normal. Note how the topof the obturator extension has been reduced ascompared to the molded pattern.
• 83. Velopharyngeal insufficiency and incompetence secondary to chemoRTSecondary to muscle wasting and fibrosisThe soft palate is shortened and does not elevate sufficientlywell to achieve velopharyngeal closure. v Treatment options v Soft palate obturator v Palatal lift prosthesis
• 84. Soft palate dysfunction secondary to chemoRTv This patient’s soft palate was foreshortened and heavily scarred secondary to chemoradiation. Elevation of the soft palate was minimal and it did not achieve closure against the posterior pharyngeal wallv Since the patient was edentulous an attempt was made to obturate the defect as opposed to fabricating a palatal lift.v The obturator prosthesis bridges the soft palate and engages the velopharyngeal deficit.v The extension crossing the soft palate slightly elevates the palate before entering the defect area.
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