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Table of Contents
Year : 2020  |  Volume : 10  |  Issue : 3  |  Page : 117-121

Management of a velopharyngeal defect with hollow speech bulb prosthesis

Department of Prosthodontics, MA Rangoonwala College of Dental Sciences and Research Centre, Pune, Maharashtra, India

Date of Submission11-Apr-2018
Date of Acceptance09-Jul-2020
Date of Web Publication21-Dec-2020

Correspondence Address:
Dr. Snehal Jaiswal
Tower 32, Flat 21-07, Amanora Township, Hadapsar, Pune, Maharashtra
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/jid.jid_32_18

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Velopharyngeal (VP) insufficiency is an anatomic defect of the soft palate which renders the palatopharyngeal sphincter incomplete. In cases where a surgically repaired soft palate is too short to contact the pharyngeal walls during function, speech aid prosthesis or speech bulbs are optimum choices of treatment. This case report elaborates the correction of hypernasality of speech associated with VP insufficiency, by means of speech bulb prosthesis. This speech bulb is a combination of cast partial denture with extension into the defect area to hold heat cure acrylic material. This retentive component was embedded in heat cure acrylic resin material to aid in retention. This improved the hypernasality, speech, comfort, retention, and overall patient acceptance.

Keywords: Hollow obturator, speech bulb prosthesis, velopharyngeal defect, velopharyngeal insufficiency

How to cite this article:
Jaiswal S, Kheur M, Lakha T. Management of a velopharyngeal defect with hollow speech bulb prosthesis. J Interdiscip Dentistry 2020;10:117-21

How to cite this URL:
Jaiswal S, Kheur M, Lakha T. Management of a velopharyngeal defect with hollow speech bulb prosthesis. J Interdiscip Dentistry [serial online] 2020 [cited 2023 Jun 10];10:117-21. Available from: https://www.jidonline.com/text.asp?2020/10/3/117/304152

   Clinical Relevance to Interdisciplinary Dentistry Top

  • The case report demonstrates the management of the patients with a velopharyngeal defect
  • Hollow speech bulb prosthesis helps in reducing the hypernasality of the speech
  • The procedure will help clinicians to manage velopharyngeal defect patients with a retentive and effective speech bulb prosthesis incorporated in a cast metal framework.

   Introduction Top

Velopharyngeal (VP) insufficiency is an anatomic defect of the soft palate leading to an incomplete closure of palatopharyngeal sphincter. VP insufficiencies may be classified on the basis of physiology and/or structural integrity as palatal insufficiency and palatal incompetency.[1] Palatal insufficiency refers to clinical situations with an inadequate length of hard and/or soft palate, which affects VP closure, but where the movement of remaining tissues is within the normal physiological limits. Palatal incompetence refers to clinical situations with essentially normal VP structures, but the intact mechanism is unable to affect VP closure.[2] Palatopharyngeal insufficiency leads to the presence of hypernasality, inappropriate nasal escape, and reduced air pressure during the production of oral speech sounds (weak pressure consonants).[3] Diagnosis is done after thorough case history recording, physical and perceptual speech assessment along with instrumental measures which include nasoendoscopy and radiographic multiplanar videofluoroscopy.[4] However, in spite of remarkable advances in the surgical management of oral and facial defects, not all palatopharyngeal defects can be completely repaired by surgery alone. The treatment options include prosthetic and surgical management, along with supplemental speech therapy. In maxillofacial prosthetics, the clinician has a responsibility of re-establishing VP integrity to provide a potential for acceptable speech.[5] A speech-aid prosthesis, also known as a pharyngeal obturator or speech bulb, is a removable maxillofacial prostheses that is usually required to restore an acquired or congenital defect of the soft palate with central component extending into the pharynx, in order to separate the oropharynx and nasopharynx during phonation and deglutition, thereby completing the palatopharyngeal sphincter.[6] Prosthetic therapy aids the patient in developing normal speech, promoting deglutition, mastication, and leads to separation of the oral and nasal cavities. The results can be instrumental in enhancing not only the esthetics but also psychological and social acceptance of these patients.[7] The speech prosthesis may be the best choice in several situations where the surgery is not the treatment of choice due to systemic, anatomic, or functional limitations or if the patient is not willing to undergo any surgical procedure.[8] Conventional treatment of speech bulb prosthesis, fabricated with either self-curing resin or heat-curing resin, has been associated with drawbacks such as inadequate marginal adaptation, soft palate discomfort, and ulcerations.[1] This article highlights a method of prosthetic management and rehabilitation of VP defect patients.

   Case Report Top

A 35-year-old male patient reported to the department of prosthodontics, with the chief complaint of difficulty in speech and swallowing. He presented with a nasal twang due to a VP defect [Figure 1]. The patient had a history of squamous cell carcinoma of the uvula for which he underwent surgical excision and chemotherapy 2 years before. He was using a cast metal framework not extending into the defect area [Figure 2]. On examination, the patient had a defect extending beyond the hard palate involving complete hard and soft palate. An altered speech was noted due to hypernasality. The patient had oral submucous fibrosis with a reduced mouth opening (21 mm) along with mild attrition of posterior teeth.
Figure 1: (a and b) Intraoral view of velopharyngeal defect

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Figure 2: The patient's old prosthesis

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A diagnosis of unrepaired soft palate with hypernasal speech was established with the help of speech intelligibility test.[9] The speech intelligibility was assessed based on a seven-point scale, by the speech pathologist [Table 1].[9],[10] Prior to the clinical procedure, the detailed treatment plan was conveyed to the patient and an informed consent was obtained.
Table 1: Seven point scale to measure speech intelligibility

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  1. Diagnostic impression of the maxillary and mandibular arch was made using irreversible hydrocolloid (Zhermack Tropicalgin Alginate Powder) in perforated stock trays
  2. Primary dental casts were fabricated using die stone (Kalabhai Ultrarock Die Stone – Extrahard die stone)
  3. A special tray was fabricated using self-cure acrylic resin (DPI RR Cold Cure Repair Material Powder) with a wire extending into the pharyngeal area
  4. The tray was checked for discomfort in the patient's mouth and the posterior extent was trimmed accordingly
  5. Border extension of the defect area was recorded using low-fusing impression compound (DPI Pinnacle tracing sticks) by asking the patient to make head movements (touch the chin to the chest, lateral head movements, and touch the ear to the shoulder) [Figure 3]a
  6. Silicone adhesive (Universal Tray Adhesive, Zhermack, Italy) was applied on the low-fusing impression compound and was allowed to dry as per the manufacturer's recommendation. The final impression of the defect was recorded with light body silicone impression material (Zhermack Zetaplus C Silicone Impression Material), followed by a pickup impression with putty silicone impression material (Zhermack Zetaplus C Silicone Impression Material) to record the dentulous area [Figure 3]b
  7. A cast was poured in die stone (Kalabhai Ultrarock Die Stone – Extrahard die stone) [Figure 3]c
  8. Retentive components of the removable appliance were fabricated on molars in the form of Adam's clasps and C clasps on premolars with 0.7 mm stainless steel wire [Figure 4]a and [Figure 4]b
  9. A conventional removable appliance was fabricated using self-cure acrylic resin extending till the defect area. This appliance was meant to be worn for 2 weeks in order to get the patient to be accustomed to the feel of a prosthesis in the mouth. The prosthesis covering the defect area was made hollow with lost salt technique [Figure 4]c[11],[12],[13],[14],[15]
  10. A retentive wire component was made of 0.7 mm stainless steel wire and contoured to the posterior pharyngeal area. This was partially embedded in the cured hard acrylic
  11. The appliance was then delivered to the patient with necessary chairside adjustments and the patient was instructed to wear the temporary prosthesis for about 2 weeks
  12. After 2 weeks, the mouth preparation for a cast partial denture framework with full palatal coverage was done. The framework had extensions made into the soft palate area to retain the final heat cure acrylic material
  13. The defect area was molded using low-fusing impression compound (DPI Pinnacle tracing sticks). Silicone adhesive (Universal Tray Adhesive, Zhermack, Italy) was applied on the low-fusing impression compound and was allowed to dry as per the manufacturer's recommendation, followed by the final impression using light body silicone impression material (Zhermack Zetaplus C silicone Impression Material)
  14. A single step final impression of the defect area and the complete maxillary arch was made with the putty and light body impression material [Figure 4] and [Figure 5](a).
  15. A cast was poured with die stone (Kalabhai Ultrarock Die Stone – Extrahard die stone) [Figure 5]b. A cast metal (Co-Cr) framework was fabricated with metal extension to help embed the heat cure acrylic material covering the defect area [Figure 6]a and [Figure 6]b
  16. The defect area was then waxed up; reverse flasking was then performed. The master cast was then invested; a second pour was performed to fill the hollow wax up. This was followed by dewaxing and packing of heat cure acrylic resin. The defect area formed in the heat cure acrylic material [Figure 7] (a) and (b)]. The prosthesis was tried in the patient's mouth for any further adjustments [Figure 8]. The defect area was then filled with table salt and was covered with self-cure acrylic resin. A hole was made in the defect bulb and a syringe filled with water was used to dissolve the salt and make it hollow.[16] The small hole was then sealed with cold cure acrylic resin
  17. Chairside adjustments were done and the final prosthesis was delivered to the patient
  18. Pretreatment and posttreatment speech intelligibility tests were carried out. The posttreatment speech showed improvement in the sounds of “s” as well as reduced hypernasality. The speech intelligibility also increased post treatment showing improvement from a score of four to two[9]
  19. The patient was advised and referred to a speech therapist for further treatment.
Figure 3: (a) Low-fusing impression compound (DPI Pinnacle tracing sticks) molded in the defect area. (b) Pickup impression of the dentulous area (Zhermack Zetaplus C Silicone Impression Material). (c) Primary cast

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Figure 4: (a and b) Conventional removable appliance using self-cure acrylic resin (DPI RR Cold Cure Repair Material Powder). (c) Intraoral view of the removable appliance

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Figure 5: (a) Final impression after mouth preparation. (b) Final cast (Kalabhai Ultrarock Die Stone – Extrahard die stone)

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Figure 6: (a) Cast metal framework (Co-Cr). (b) CPD framework intraoral view

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Figure 7: (a and b) CPD framework with hollow speech bulb

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Figure 8: Intraoral view – obturator in the mouth

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   Discussion Top

The three-dimensional muscular wall, VP sphincter is formed by the soft palate, lateral, and posterior pharyngeal walls. Adequate VP closure is required for proper speech and swallowing. Lack of soft tissue in the VP sphincter will lead to VP insufficiency.[17] The primary objectives of prosthodontic therapy are the restoration of mastication, deglutition, and to make speech functionally acceptable. The definitive prosthesis generally used for VP defect patients is an obturator. An obturator should be a single piece.[18] It can either be closed or open type. Some of the disadvantages of an open type obturator include an unpleasant odor due to the accumulation of nasal secretions and difficulty in polishing the internal surfaces of the obturator.[19] Hence, a closed lightweight hollow bulb obturator is preferred as it is easier to maintain.[20] Hollow bulb obturators reduce the weight of the prostheses from 6.55% to 33.06% depending on the size of the defect when compared to solid obturators. The decreased weight also results in increased retention, better patient acceptability, and comfort.[18] Although obturators aid in mastication and deglutition, speech defects still persist to a large extent. Therefore, the routine practice has been to advise an intensive speech therapy for such patients.[21] In patients with cleft palate, the VP dysfunction is responsible for abnormalities in nasal resonance.[22] The speech bulbs, in these cases, act as a stimulus to increase movements of the pharyngeal walls and palate, thereby improving VP closure.[23] However, existing articulation errors are also responsible for reduced speech intelligibility.[24] Correlation between speech intelligibility and speech prosthesis is crucial, and understanding this dimension thoroughly will definitely aid in enhancing speech intelligibility through prosthesis.[21] Palatography techniques can be used to obtain articulatory records between the palate and tongue during various speech sounds. Various studies have shown that the voice quality was best when the speech bulb was positioned on the posterior pharyngeal and lateral pharyngeal wall.[25] In this case, the framework extended from the prosthesis posteriorly and laterally to render enough palatal support, improving function, swallowing, and reduced the hypernasality of speech. This was reaffirmed by asking the patient to say “s” sounds after the insertion of prosthesis.

   Conclusion Top

A definitive prosthesis in the form of a Co-Cr cast partial denture with a hollow bulb in the defect area can be a suitable treatment option for patients with palatopharyngeal defects; in order to restore their speech, swallowing, and masticatory abilities.

   Declaration of patient consent Top

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

   References Top

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Agrawal KK, Singh BP, Chand P, Patel CB. Impact of delayed prosthetic treatment of velopharyngeal insufficiency on quality of life. Indian J Dent Res 2011;22:356-8.  Back to cited text no. 3
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  [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7], [Figure 8]

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