Rehabilitation of a partial glossectomy patient: Palatal augmentation prosthesis.

Tongue-palate contact is necessary for the production of normal speech, and the proper location of the tongue on the palate during certain sounds is important. Partial glossectomy leads to difficulty in tongue-palate articulation during speech, and it becomes difficult for a patient to reach the palate with the tongue to form certain sounds. In-depth knowledge of the production of different sounds can be used as a diagnostic aid in determining the thickness of the palatal augmentation prosthesis fabricated to rehabilitate such patients. A functional wax technique is used to make a functional impression of tongue-palate contact during the speech.

INTRODUCTION

The posterior lateral border of the tongue is one of the most common sites for oral carcinomas. The treatment of choice for such lesions is surgical therapy in combination with radiotherapy and chemotherapy.[1] Posttreatment, patients are left with different levels of impairment of mastication, deglutition, and speech depending on the extent of surgical resection and partial or complete glossectomy with or without mandibulectomy. Tumor location in the anterior tongue has the biggest impact on articulation quality, whereas tumor in the tongue base has the biggest impact on swallowing.[2] It is a very challenging situation for a maxillofacial prosthodontist to rehabilitate such patients. Palatal augmentation prosthesis (PAP) has been used successfully to allow reshaping the hard and/or soft palate to improve tongue/palate contact during speech and swallowing.[3] This could be a removable partial denture or complete denture prosthesis.

The thickness of the PAP will have a substantial effect on the phonetics and swallowing pattern of the patient. In-depth knowledge of production of different sounds can be used as a diagnostic aid in understanding the compensatory articulation used by glossectomy patients and in determining the thickness of the PAP.

CASE REPORT

A 61-year-old male reported to the Department of Prosthodontics with chief complaints of difficulty in swallowing and impaired speech due to partial resection of the tongue. Three years back, the patient was diagnosed with squamous cell carcinoma involving the right lateral border of the tongue and just crossing midline in the anterior two-third of the tongue. The patient underwent anterior two-third glossectomy and neck dissection.

The patient had diabetes for the last 5 years and was under medication. Extraoral examination indicated that there was little collapse of soft tissue on the right cheek and the right side of the neck. The patient had adequate mouth opening (50 mm) as seen in Figure 1. Intraoral examination depicted that the lingual sulcus was completely obliterated on the resected side. The patient was dentulous in both the jaws with few teeth missing [Figures 2 and 3]. The right-sided floor of the mouth is concave and essentially without function [Figure 4]. The floor of the mouth was reconstructed using a split-thickness skin flap from his thigh. The patient was wearing PAP for the last 1½ years which had a broken clasp. The prosthesis had helped the patient in speech and swallowing to some extent. The prosthesis did not have the required stability and retention. It was flat on the oral surface as seen in Figure 5 and it lacked the contours required for phonetics.

Figure 1

Maximum mouth opening

Figure 2

Maxillary arch

Figure 3

Mandibular arch

Figure 4

Right side deficiency

Figure 5

Old prosthesis with a flat oral surface

The floor of the mouth had altered posture and restricted movements. Whenever there is residual function in the remaining floor of the mouth, PAP is considered.[3] The treatment plan thus included fabrication of PAP with oral surface being contoured by functional palatal impression technique using functional wax on the oral surface and reproducing the same in the final prosthesis.[4]

Primary impressions were made in addition silicone material in a stock tray, and primary casts were made. A self-cure hollow prosthesis was fabricated to work as a base on which molten Korecta wax would be applied to make functional records [Figure 6]. The clasps’ design was also changed to make it more retentive and stiffer as compared with the previous prosthesis in which there was a long clasp arm, which resulted in increased flexibility making it prone to fracture. This prosthesis was checked for comfort and retention before the records were made. The tongue-palate contacts were evaluated according to the clarity of speech during specific sounds.

Figure 6

Hollow self-cure prosthesis

The wax was painted using a brush on the oral side of the hollow prosthesis, and the patient was instructed to functionally manipulate the wax by the floor of the mouth by repeating the linguovelar sounds /k/, /kh/, /g/, and /gh/ for the posterior palatal tracing. For the anterior palatal tracing, the linguoalveolar sounds /t/ and /d/ were used. This sounds enabled the tongue to articulate with the different positions on the palate. Additional wax was added to the anterior palatal region resulted in a significant improvement for the fricative and affricative (hard) linguopalatal sounds /s/, /sh/, /z/, /zh/, /ch/, and /jh/ as shown in Figure 7.[45] For tracing the swallowing patterns, the patient was asked to swallow saliva multiple times. Phonetics was checked again, and finally, a proper balance was achieved between speech and swallowing tracings.[6] It should be checked that both functions are performed without any restriction. The prosthesis was finally processed with the heat cure acrylic resin. Laboratory putty index was made before flasking to make sure that the patterns recorded were not distorted by any heat or pressure generated [Figures 8–10]. A smooth palate without rugae was preferred by the patient for easier removal of food during eating [Figure 11].[4] The rainbow passage especially designed for Indian population was used to assess the speech intelligibility without the prosthesis,[7] with the previous prosthesis and with the new prosthesis.

Figure 7

Intraoral functional wax recording

Figure 8

Seating the records on the cast

Figure 10

Protection of the records with putty index

Figure 11

Final prosthesis intraorally

Flasking for acrylization

The prosthesis was delivered to the patient and follow-ups were done after 24 h and 1 week. After 1 week, speech therapy and oral exercises were initiated to improve the efficiency of the prosthesis. The patient was asked to suck the saliva forcibly inside the pharynx to improve the swallowing abilities. He was also asked to do exercises involving muscles of cheeks, lips, and floor of mouth such as blowing and sucking exercises to improve articulation during speech.[8]

DISCUSSION

Tongue coordinates with cheeks to keep the food on occlusal surface of the teeth. It also plays an important role in bolus formation and bolus propulsion into the pharynx. Increased space between the palate and the floor of the mouth in addition to limited or no movement of tongue can also lead to adherence of food to palate and inability to clean the food particles from the palatal vault. This also results in altered speech due to lack of contact of the tongue with the teeth (linguodental), the alveolar ridge (linguoalveolar), the hard palate (linguopalatal), and the soft palate (linguovelar).

Tongue is the principle articulator for speech and learning its position for a given sound is the key to speech learning [Figure 12]. The source of production of sound is the air in the lungs which passes through the vibrators (vocal folds in the larynx) and as it en routes to the exterior, i.e., larynx, pharynx, nasal cavity, and oral cavity, the sound is modified by various structures which act as resonators to reinforce the original sound wave. Furthermore, it involves precise coordination between different articulators that refines the final sound. The articulators move toward each other to create an obstruction that shapes the air in a particular fashion.

Figure 12

Normal position of tongue

Vocal folds, velum and pharynx, velum and tongue, tongue and palate, lips and teeth, and lips themselves are prime articulators. The point of maximum obstruction is called the place of articulation and the way the obstruction forms and releases is the manner of articulation, e.g., stops (plosive) and fricatives. This involves six valves; bilabial, labiodental, linguodental, linguoalveolar [Figure 13], linguopalatal [Figure 14], and linguovelar [Figure 15] as shown in Tables 1 and 2.[8]

Figure 13

Position of tongue in linguoalveolar sounds

Figure 14

Position of tongue in linguopalatal sounds

Figure 15

Position of tongue in linguovelar sounds

Table 1

Manner of production - Hindi consonants[

Place	Manner of production
	Plosives	Fricatives	Affricative	Nasal
Bilabial
Labiodental
Linguodental
Linguoalveolar
Linguopalatal
Linguovelar

Table 2

Manner of production - English consonants[

Place	Plosives	Manner of production
		Fricatives	Affricative	Semi vowel	Nasal
Bilabial	P (pole)B (bowl)			W (watt)	M (sum)
Labial dental	F (fat)v (vat)
Linguodental	T (thigh)h (thy)
Linguoalveolar [Figure 14]	T (toll)d (dole)	S (seal)z (zeal)		L (lot)	N (sun)
Linguopalatal [Figure 15]		Z (azure)	Ch (choke j (joke)
Linguovelar [Figure 16]	K (koal)g (goat)				Ng (sing)

Nonetheless, glossectomy definitely hampers the production of linguodental, linguoalveolar, linguopalatal, and linguovelar sounds [Figure 16]. This basic knowledge was applied to do the functional wax technique. Since the patient had right side defect, the PAP required more addition of wax on that side [Figure 17]. Molten wax was painted in segments to record one group at a time. Linguoalveolar [Figure 18] sounds were used first, linguopalatal [Figure 19] sounds the next, and linguovelar at the end [Figure 20].

Figure 16

After glossectomy

Figure 17

Cross-section image to show palatal augmentation prosthesis

Figure 18

Addition of wax for linguoalveolar sounds

Figure 19

Addition of wax for linguopalatal sounds

Figure 20

Addition of wax for linguovelar sounds

The prosthodontic management of glossectomy patients depends on the size of the defect. The patients with partial tongue resection often include PAP to lower the palatal vault, while the management of total glossectomy usually requires a mandibular tongue prosthesis.[9] The purpose of the prosthodontic rehabilitation in such cases is to reduce the size of the oral cavity for better speech and directing food into the esophagus for efficient swallowing. Undoubtedly, the rehabilitation in such cases is a challenging process for both the prosthodontist and the patient. The functional utility of a static prosthesis is limited as it cannot replace the mobile tongue, which is capable of infinite movements in swallowing and speech.

SUMMARY

Surgeries in cases of oral carcinoma involving the tongue and the floor of the mouth often result in the reduced mobility of the tongue during speech and deglutition. Partial glossectomy patients require prosthetic augmentation with a prosthesis that lowers the palatal vault to restore tongue-palate contact. Phonetics can be used to diagnose the regions deficient in tongue-palate contact and to reevaluate speech after prosthetic rehabilitation.[10] A functional impression is important in the fabrication and proper placement of PAP. Teamwork with a speech pathologist can be helpful during diagnosis and management in such cases.[11] Speech therapy is also necessary for significant rehabilitation of speech. This will result in improved lifestyle and socialization in these patients.

Declaration of patient consent

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

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.