Complete Dentures in Prosthetic Dentistry II

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Questions and Answers

Which structure is bounded externally by the cheek and internally by the residual ridge?

Labial vestibule

Sublingual salivary gland area

Buccal vestibule (correct)

Lingual pouch

What is the function of the palatoglossus muscle?

Forming the labial vestibule

Creating the lingual pouch

Influencing the masseter muscle area

Causing sore throat if over-extended (correct)

What should not be covered by the denture base?

Lingual frenulum

Sublingual salivary gland area (correct)

Labial frenulum

Masseter muscle influencing area

Where is the vibrating line of the soft palate located?

Between hamular notch and pterygoid hamulous Signup and view all the answers

What is the function of mandibular labial flange?

Extending in mandibular labial vestibule Signup and view all the answers

Where is lingual pouch bounded posteriorly?

By palatoglossus muscle Signup and view all the answers

Where should the upper denture extend between?

Hamular notch and pterygoid hamulous Signup and view all the answers

What structure connects mucosa of lower lip to mucosa of alveolar process at midline?

Mandibular labial frenulum Signup and view all the answers

Which of the following is an indication for complete dentures?

Extensive bone loss and periodontal disease Signup and view all the answers

What is the nasolabial sulcus?

A crease extending from the ala of the nose to the corner of the mouth Signup and view all the answers

What does the vermilion border refer to?

The transitional epithelium between lip mucous membrane and skin Signup and view all the answers

What is mentolabial sulcus?

A fold running between the lower lip and chin Signup and view all the answers

Which area needs to be relieved in the denture to avoid excessive pressure and ensure proper fit?

Maxillary incisive papilla Signup and view all the answers

What is the role of the alveolar ridge in the upper jaw?

Primary stress-bearing area Signup and view all the answers

What is the function of rugae in the anterior third of the hard palate?

Role in speech Signup and view all the answers

Which structure needs to be included in the impression for good bearing surface in the upper jaw?

Maxillary tuberosity Signup and view all the answers

What is the function of modiolus near the mouth angle?

Preventing sunken cheeks Signup and view all the answers

Which landmark is important for proper extension of upper dentures?

Posterior palatal seal Signup and view all the answers

Which material can be used to fabricate metallic impression trays?

Stainless steel Signup and view all the answers

What is the recommended border extension of an impression tray in relation to the vestibular depth?

2mm short of the vestibular depth Signup and view all the answers

Which muscle should not be interfered with by the border extension of an impression tray?

Buccinator muscle Signup and view all the answers

What is the purpose of angulating the handle of an impression tray?

To exclude the lips Signup and view all the answers

What is the function of non-metallic impression trays?

Carrying and controlling impression material Signup and view all the answers

What should the entire border of an impression tray be?

Smooth and rounded Signup and view all the answers

Which type of tray is more accurate and comfortable for the patient?

Custom trays Signup and view all the answers

What material can custom trays be made of?

Light cure acrylic resin only Signup and view all the answers

What determines the material choice for custom trays?

Various factors including fabrication time, material properties, and hazardous effects Signup and view all the answers

What do spacer and stop trays use to provide extra space for impression material with higher viscosity?

Wax spacer Signup and view all the answers

What are the criteria for special tray construction?

Not impinging on movable structures, extending borders beyond the vestibular sulcus, and ensuring sufficient rigidity and thickness Signup and view all the answers

What serves to carry impression material to the mouth and support it during polymerization?

Stock trays Signup and view all the answers

What is the function of the spacer in the custom tray?

To properly position the tray during border molding procedure Signup and view all the answers

What is the purpose of applying a separating medium on the cast?

To prevent acrylic resin from sticking to the cast Signup and view all the answers

What is the primary function of a handle on a custom tray?

Supporting the lip while making an impression Signup and view all the answers

Why should disposable trays be recommended to prevent cross-contamination?

To ensure patient safety and hygiene Signup and view all the answers

What is the purpose of stops in a custom tray?

To ensure proper contact with the ridge in specific areas Signup and view all the answers

What is the function of finger rests on a mandibular tray?

Stabilize tray in mouth and equal distribution of pressure Signup and view all the answers

What is the purpose of relief wax in custom trays?

To provide relief in specific marked areas on the cast Signup and view all the answers

What should be done before using trays on patients?

Trays should be cleaned properly and disinfected Signup and view all the answers

Study Notes

Angle of mouth (commissance): Dentures should be designed to support the natural mouth angle, preventing angular cheilitis caused by continuous wetting from saliva.
Modiolus: The meeting point of facial muscles near the mouth angle, which can be displaced due to teeth loss, causing the appearance of sunken cheeks. Lower denture in the premolar region should have a thin margin to prevent the modiolus from lifting the denture.
Ala of the nose, ala tragus line: An imaginary line from the ala of the nose to the tragus of the ear is important for proper extension of upper dentures.
Intraoral landmarks: The oral cavity consists of a vestibule and oral cavity proper. After teeth extraction, the alveolar bone is resorbed, and the remaining part is called a residual ridge.
Maxillary anatomical landmarks: The alveolar ridge is the primary stress-bearing area in the upper jaw. The crest of the ridge is the highest point, and the maxillary tuberosity is a rounded prominence behind the distal end of the ridge, which should be included in the impression for good bearing surface.
Palatine vault: The palatine vault is formed by the hard palate anteriorly and the soft palate posteriorly. Its shape can be high and U-shaped, or flat and shallow, and it plays an important role in denture support and stability.
Incisive papilla: The incisive papilla is a pad of fibrous connective tissue overlying the nasopalatine canal and is used as a landmark for correct placement of artificial central incisors. Upper dentures should be relieved to avoid pressure on the incisive nerve, which may cause a burning sensation.
Torus palatinus: A raised, bony ridge running down the center of the hard palate, which needs to be relieved for proper denture fit if it's small. If it's too big, it may need to be removed surgically.
Rugae: Irregular shaped ridges in the anterior third of the hard palate that play a role in speech. They should not be disturbed during the impression process to ensure maximum comfort.
Fovea palatinae: Openings of the ducts of minor salivary glands, which are important landmarks for posterior border extension of the upper denture.
Mandibular anatomical landmarks: The alveolar ridge, which is important for proper extension and occlusal plane location of the mandibular denture. The retromolar pad should not be displaced during the impression process. The external oblique ridge and buccal shelf are areas of dense bone that should be covered by the lower denture to provide support and resist masticatory forces.
Impression process: Relief areas, such as the maxillary incisive papilla, median raphe, and torus palatinus, need to be relieved to eliminate excess pressure and ensure proper denture fit.
Border structures: Maxillary dentures have labial frenulum, labial vestibule, and buccal frenulum as border structures.
Stress-bearing areas: The primary stress-bearing areas, such as the crest of the ridge and the palatal flat areas, can resist the vertical forces of occlusion.
Relief areas: Genial tubercles, sharp bony prominences, and the mental foramen require relief areas in the denture to eliminate excessive pressure and promote proper fit.
Denture foundation area: The denture foundation area, which includes the surface of the oral vestibule, determines the amount of force applied to the denture. A larger surface area reduces the force applied, making it easier to support the denture.
According to the method of fabrication, there are stock trays and custom trays or special trays for making dental impressions.
Stock trays are ready-made and come in specific sizes, while custom trays are fabricated based on a particular patient's cast.
Stock trays are reusable after sterilization, while custom trays are unique to the patient and discarded.
Stock trays serve to carry impression material to the mouth and support it during polymerization. They are available in different materials and sizes.
Factors affecting selection of stock trays include the type of mouth, type of impression material, size of the arch, and the form of the arch.
Custom trays are made from a cast recovered from primary impression and used to make a final impression. They are more accurate and comfortable for the patient.
Custom trays can be made of metallic or non-metallic materials, such as cold cure acrylic resin, hot cure acrylic resin, or light cure acrylic resin.
The material choice for custom trays depends on various factors such as fabrication time, material properties, and hazardous effects.
Close-fit trays are directly adapted to the cast, while spacer and stop trays use a wax spacer to provide extra space for impression material with higher viscosity.
Criteria for special tray construction include not impinging on movable structures, extending borders beyond the vestibular sulcus, and ensuring sufficient rigidity and thickness.

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Description

Test your knowledge about complete dentures, a removable dental prosthesis that replaces the entire dentition and associated structures of the maxilla or mandible. Learn about the indications and considerations for complete dentures.