Journal of Interdisciplinary Dentistry

: 2020  |  Volume : 10  |  Issue : 3  |  Page : 117--121

Management of a velopharyngeal defect with hollow speech bulb prosthesis

Snehal Jaiswal, Mohit Kheur, Tabrez Lakha 
 Department of Prosthodontics, MA Rangoonwala College of Dental Sciences and Research Centre, Pune, Maharashtra, India

Correspondence Address:
Dr. Snehal Jaiswal
Tower 32, Flat 21-07, Amanora Township, Hadapsar, Pune, Maharashtra


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.

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;10:117-121

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 2021 Sep 18 ];10:117-121
Available from:

Full Text

 Clinical Relevance to Interdisciplinary Dentistry

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


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

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}{Figure 2}

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}


Diagnostic impression of the maxillary and mandibular arch was made using irreversible hydrocolloid (Zhermack Tropicalgin Alginate Powder) in perforated stock traysPrimary dental casts were fabricated using die stone (Kalabhai Ultrarock Die Stone – Extrahard die stone)A special tray was fabricated using self-cure acrylic resin (DPI RR Cold Cure Repair Material Powder) with a wire extending into the pharyngeal areaThe tray was checked for discomfort in the patient's mouth and the posterior extent was trimmed accordinglyBorder 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]aSilicone 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]bA cast was poured in die stone (Kalabhai Ultrarock Die Stone – Extrahard die stone) [Figure 3]cRetentive 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]bA 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]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 acrylicThe appliance was then delivered to the patient with necessary chairside adjustments and the patient was instructed to wear the temporary prosthesis for about 2 weeksAfter 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 materialThe 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)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).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]bThe 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 resinChairside adjustments were done and the final prosthesis was delivered to the patientPretreatment 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]The patient was advised and referred to a speech therapist for further treatment.{Figure 3}{Figure 4}{Figure 5}{Figure 6}{Figure 7}{Figure 8}


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.


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

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.


1Kahlon SS, Kahlon M, Gupta S, Dhingra PS. The soft palate friendly speech bulb for velopharyngeal insufficiency. J Clin Diagn Res 2016;10:ZD01-ZD02.
2Beumer J, Curtis A, Marunick MT. Maxillofacial Rehabilitation: Prosthodontic and Surgical Considerations. St Louis: Ishiyaku Euro-America; 1996. p. 285-329.
3Agrawal 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.
4Aboloyoun AI, Ghorab S, Farooq MU. Palatal lifting prosthesis and velopharyngeal insufficiency: Preliminary report. Acta Med Acad 2013;42:55-60.
5Shetty NB, Shetty S, E N, D'Souza R, Shetty O. Management of velopharyngeal defects: A review. J Clin Diagn Res 2014;8:283-7.
6The glossary of prosthodontic terms. J Prosthet Dent 2005;94:10-92.
7Kumar R, Raghavan R, Jishnu S, Monisha VS, Raj JS, Sathish S. Prosthetic consideration in management of cleft lip and palate patients. Science 2016;5:27-30.
8Bohle G 3rd, Rieger J, Huryn J, Verbel D, Hwang F, Zlotolow I. Efficacy of speech aid prostheses for acquired defects of the soft palate and velopharyngeal inadequacy—clinical assessments and cephalometric analysis: A Memorial Sloan-Kettering Study. Head Neck 2005;27:195-207.
9Shipley KG, McAfee JG. Assessment in Speech Language Pathology: A Resource Manual. 4th ed.. Kentucky: Delmar Cengage Learning; 2008.
10Kumar P, Jain V, Thakar A. Speech rehabilitation of maxillectomy patients with hollow bulb obturator. Indian J Palliat Care 2012;18:207-12.
11Brown KE. Fabrication of a hollow-bulb obturator. J Prosthet Dent 1969;21:97-103.
12Parel SM, LaFuente H. Single-visit hollow obturators for edentulous patients. J Prosthet Dent 1978;40:426-9.
13Matalon V, LaFuente H. A simplified method of making a hollow obturator. J Prosthet Dent 1976;36:580-82.
14Nidiffer TJ, Shipmon TH. The hollow bulb obturator for acquired palatal openings. J Prosthet Dent 1957;7:126-34.
15Habib BH, Driscoll CF. Fabrication of a closed hollow obturator. J Prosthet Dent 2004;91:383-5.
16Srinivasan J, BabuRajan K, Suresh V. Fabrication of interim hollow bulb obturator using lost salt technique: A case report. Journal of Scientific Dentistry 2011;1:37-40.
17Tuna SH, Pekkan G, Gumus HO, Aktas A. Prosthetic rehabilitation of velopharyngeal insufficiency: Pharyngeal obturator prostheses with different retention mechanisms. Eur J Dent 2010;4:81-7.
18Wu YL, Schaaf NG. Comparison of weight reduction in different designs of solid and hollow obturator prostheses. J Prosthet Dent 1989;62:214-7.
19Beumer J, Curtis TA, Firtell DN. Maxillofacial Rehabilitation. Prosthodontic and Surgical Considerations. St. Louis: The C.V. Mosby Co.; 1979.
20Shimodaira K, Yoshida H, Yusa H, Kanazawa T. Palatal augmentation prosthesis with alternative palatal vaults for speech and swallowing: A clinical report. J Prosthet Dent 1998;80:1-3.
21Rajan NS, Muthiah L, D'souza J, George BT. Evaluation of speech intelligibility of a cleft palate patient with speech prosthesis before and after palatographical analysis and prosthesis modification. J Biosci Med 2017;5:60.
22Kummer AW. Speech and resonance disorders related to cleft palate and velopharyngeal dysfunction: a guide to evaluation and treatment. Perspectives on School-Based Issues 2014;15:57-74.
23Tachimura T, Nohara K, Fujita Y, Wada T. Change in levator veli palatini muscle activity for patients with cleft palate in association with placement of a speech-aid prosthesis. Cleft Palate Craniofac J 2002;39:503-8.
24Bzoch KR. Introduction to the study of communicative disorders in cleft palate and related craniofacial anomalies. Communicative disorders related to cleft lip and palate. 5th ed. Austin: Pro-Ed; 2004:3-66.
25Reisberg DJ. Dental and prosthodontic care for patients with cleft or craniofacial conditions. Cleft Palate Craniofac J 2000;37:534-7.