tongue prosthesis

TONGUE PROTHESIS

Clinical significance of the Tongue
1- Tongue size
2- Tongue position
3- Muscular development
& Neuromuscular control

Role of the Tongue in peripheral lingual seal

1- The tip of the tongue controls the bolus of food & places it on the occlusal surface of the teeth. 2- The lingual extensions cover the sublingual glands. 3-Activation of superior constrictor muscle affect the sealing in the distolingual area, while the activation of the mylohyoid muscle affect the sealing in the molar area. Activation of the genioglossus muscle influence the sealing in the sublingual fold space.

Role of The Tongue in Posterior Palatal Seal

During swallowing, the dorsum of the tongue presses against the posterior border of the tray, displacing the palatal tissues superiorly with only minimal downward pressure by the tensor veli palatini, producing an effective posterior palatal seal.

Role of the Tongue in centric jaw relation

1- Contour of the occlusal rim:
a- The occlusion rim must have arch forms that are correctly related to the pattern of the tongue & muscular activities. b- The lateral borders & the tip of the tongue must have freedom to move naturally during speech & deglutition.

2- Occlusal plane determination:

The occlusal plane should be below the lateral borders of the tongue to prevent food from falling into the lingual vestibule.
Role of the Tongue in centric jaw relation
Approaches for occlusal plane determination:Camper’s planeCorner of the mouth & retro-molar padLateral borders of the tongue

Role of the Tongue in arch arrangement & size of posterior teeth

1- The proper position for the teeth is at a point where the pressure of the tongue & cheek balance each other, in this way the denture will occupy the neutral zone in the mouth. 2- The lower posterior teeth must be positioned so that when the tongue is at rest it lies comfortably against them & yet they don’t encroach upon the cheek & not overhang the tongue. 3- The occlusal surface area of the artificial post. teeth should be smaller than that of the natural one in order to reduce the load on the supporting tissues.

Role of the Tongue in contouring the lingual flange

The lingual flange should incline medially & inferiorly.
Role of the Tongue in managing the finished denture
Normal resting tongue position & swallowing pattern is important in retaining & stabilizing both upper & lower dentures.

Removable Prostheses For Glossectomy Defects

Glossectomy Defect
Malignant tumors of the tongue, floor of the mouth &/or the mandible often require extensive resection of the tongue. Glossectomy, an extremely disabling surgical procedure. Affect the neuromuscular coordination of the tongue that plays an important role in 3 functions: mastication, swallowing and speech. The nature of disabilities is dependant upon the volume & site of resected tissues, impact of radiation, motor & sensory control of the remaining tongue.
Normal swallowing alone requires the fine coordination of 12 cranial & 6 cervical nerves, and 60 muscles. This create a great challenge for clinician to replace this sensitive, highly mobile, muscular organ with hard immobile acrylic resin/or such material and restore acceptable oral competency & function.

Prosthodontic Rehabilitation following total & partial Glossectomy

Tongue defects due to tumor removal can result in either…… total or partial glossectomy. Speech or deglutition aid prosthesis to be placed either in the maxillary or mandibular arch

The factors influencing prosthetic prognosis of restoring tongue:

Amount & position of the tongue remaining part(s). The retaining means (teeth, denture or implants) are very important especially in patient with total glossectomy . The procedure combines with the glossectomy (eg. Mandibulectomy, palatectomy, radiation therapy). The condition of surrounding structures. Patient acceptance.


Major objectives of prosthetic rehabilitation for total glossectomy (TG) without surgical reconstruction:
Reduce oral cavity size to improve resonance. Direct food bolus into oro-pharynx. Protect the underlining fragile mucosa if skin flaps not used. Develop surface contact with surrounding structures during speech & swallowing. Improve appearance & psychological adjustment.

Materials used to construct tongue prostheses

In the past: Plastic materials, such as silicon or polyvinyl chloride that used for facial reconstruction (disadvantage: difficult to master), or acrylic materials which have allergic effect on manufacturer or patients.

Recently: Polysiloxane materials, which overcomes many former shortcomings has evolved

Not toxic or allergic. Can well withstand the forces to which it’s subjected. A close texture & natural appearance of the tongue.Also it gives a retention means for the tongue prosthesis to the max. dent. (Especially in patients with tightened scar tissue in the floor of the mouth). Easily cleaned. Easily manipulated (removed by gentle squeezing it from its undercut). Advantages of polydimethylsiloxane-acrylic resin prosthesis:



Cannot replace all the functions of the tongue.The ability to replace the speaking is difficult, although it’s a plastic & moldable one (it may help in limited degree in field the space & improve the resonance of sounds only). Disadvantages of polydimethylsiloxane-acrylic resin prosthesis:

Treatment of choice: Mandibular tongue prostheses

Define as: dome-shape prosthesis fills the palatal vault, as much as normal tongue when mouth closed.
Types: For speech. For swallowing. For both speech & swallowing.
Total Glossectomy


For speech: should have ant. elevation to facilitate articulation of ant. linguo-alveolar sounds, /t/ & /d/. it also should have posterior one to articulate for linguo-palatal sounds, /g/ & /k/. Both improve vowel production.

For swallowing: should be sloped posteriorly to guide food to pharynx.

For both speech & swallowing: both types of TP can fabricate as interchangeable speech & swallowing prostheses attached via the retentive button on the base portion (this used for highly motivated patient).

In mandibular TP, checking for adequate palatal contact of the tongue. And ensuring freedom in lateral and protrusive movements.
Some important notes


In total glossectomy, the mandibular tongue prosthesis is the treatment of choice, but in situation involving: complete edentulous patient and an irradiated, desorbed mandibuler ridge or patient with very week abutment, Maxillary TP / PAP should be considered.



The modified maxillary denture replaces the tissue volume lost by the glossectomy and will assist the patient in swallowing. By wax that modified intraorally until maximum contact is developed with the floor of the mouth during swallowing, then processed in acrylic resin