ANATOMY AND PHYSIOLOGY IN RELATIONTO COMPLETE DENTURE CONSTRUCTION

DENTURE BEARING AREAS

DENTURE LIMITING STRUCTURES

1 . Loss of teeth .

2 . Resorption of the alveolar bone .

3 . The mandible become closer to the nose .

4 . Lack of support to the facial muscles .

Changes That Happen After Teeth Loss :

Ridges

Changes That Happen After Teeth Loss :

Changes That Happen After Teeth Loss :

Face :

Anatomical Landmarks In Relation To Complete Denture :

Inter pupillary line

Ala Tragus Line

Modulus

Naso – Labial sulcus

Labiomental sulcus

Extra Oral Landmarks

Inter pupillary line

Ala Tragus Line

Naso – Labial sulcus

Modulus

Labiomental sulcus

Anterior Occlusal Plane Determination

Classes of jaw relations

Becomes deeper with age and with loss of teeth

Posterior Occlusal Plane Determination

Become Flat With The Loss Of Teeth

Denture Bearing areas / UpperIncisive Papilla

Incisive Papilla

1 . The incisive papilla is a thick part of the mucous membrane covering the incisive foramen.

2 . It is located at the anterior end of the median palatine raphae .

3 . The nasopalatine nerves and vessels pass through the incisive foramen to supply the anterior 2 / 3 of the palate.

4 . In some cases due to the excessive bone resorption, the papilla may lie on the crest of the ridge.

5 . The incisive papilla should be relieved to avoid pressure on the incisive nerves and vessels.

Intra Oral Landmarks

Denture Bearing areas / Upper

Raugae Area

Palatine Rugae

1 . It is an irregularly shaped elevations of soft tissue extending laterally from the midline in the anterior part of the hard palate.

2 . It serves as one of stress bearing areas in the palate .

Denture Bearing areas / Upper

Median Palatine Raphae

Median Palatine Raphae

1 . The midline of the hard palate is covered by a thin layer of mucoperiostium , that covers the median palatine suture .  2 . That suture joins the right and the left halves of the hard palate.

3 . It is usually relieved to increase denture stability by preventing its rocking .

Denture Bearing areas / Upper

Fovia Palatina

Fovia Palatina

1 . It helps in the determination of the posterior border of the upper denture.

2 . The posterior border of the upper denture should be 2 mm posterior to the fovea Palatina .

Residual Alveolar Ridge

To Continue ( Bearing Areas)

Residual Alveolar Ridge

1 . It should be firm specially in the lower ridge .

2 . It covers the crest of the lower ridge.

3 . Its mobility may cause pressure symptoms under the lower denture.

4 . Also can affect denture stability .

To Continue ( Bearing Areas)

Buttress Part Of Bone

Buttress Part Of Bone

1 . It is formed of the lower portion of the zygomatic process of the maxilla (the area above the first molar teeth) .

2 . It provides excellent resistance to the vertical forces(Support).

To Continue ( Bearing Areas)

Tubirosity

Tubirosity

1 . It is important for retention and support of the upper denture against lateral movement.

2 . The denture should cover it , because it is one of stress bearing areas in the upper aw .

Immovable Part of Soft Palate

To Continue ( Bearing Areas)

Immovable Part of Soft Palate

1 . The immovable part lies adjacent to the hard palate and the movable part lies more posterior.

2 . The posterior edge of the upper denture should end at the junction of these two parts .

Labial Frenum

Denture Limiting Structures (Upper)

Labial Frenum

It must be relieved in the denture by making a V-shape notch in the labial flange opposite to its position .

Labial Vestibule

Denture Limiting Structures (Upper)

Labial Vestibule

1 . It Is the reflection of the mucosa of the lip to the mucosa of the alveolar process in the labial vestibule.

2 . The denture in this area is in relation to the orbicularis oris and the superior incisive muscles .

3 . These muscles limit the thickness and the length of the labial flange of the denture.

Buccal Frenum

Denture Limiting Structures (Upper)

Buccal Frenum

1 . It is a fold of mucous membrane (tendon of the buccinator muscle) varies in size in number and in position .

2 . A notch is made in the denture flange opposite to its position to facilitate its functional movements.

Buccal Vestibule

Denture Limiting Structures (Upper)

Buccal Vestibule

1 . The denture in this area is related to buccinator muscle.

2 . Buccal flanges must extend in the buccal vestibule .

3 . Due to the horizontal direction of the fibers of this muscle; the contraction of this muscle will not displace the denture.

Denture Limiting Structures (Upper)

Hamular Notch

Hamular Notch

1 . It is one of the important landmarks for determination of the posterior limit of the upper denture .

2 . A straight line from hamular notch on one side to the other on the other side determines the posterior limit of the upper denture

Vibrating Line ( Ah Line)

Denture Limiting Structures (Upper)

Vibrating Line ( Ah Line)

1 . It separate the movable part from the immovable part of the soft palate.

2 . This line is 2mm posterior to the fovea palatine .

3 . This line determines the posterior end of the upper denture.

Retro Molar pad

Denture Bearing and Limiting Structures (Lower)

Retro Molar pad

1 . It is a pear shaped area of mucous membrane at the posterior end of the mandibular ridge and anterior to the pterygo mandibular raphae .

2 . It consists of mucous glands , temporal tendon , fibers of the buccinators and superior constrictor muscle .

3 . Lower denture should cover this area for retention and to cover the buccal shelf of bone (Primary stress bearing area) .

Buccal Shelf Of Bone

Denture Bearing and Limiting Structures (Lower)

Buccal Shelf Of Bone

1 . The area that lies between the crest of the residual ridge and the external oblique ridge.

2 . It is the primary stress bearing area in the lower arch .

3 . It forms good support for the lower denture .

Buccal Vestibule

Denture Bearing and Limiting Structures (Lower)

Buccal Vestibule

1 . The denture in this area is related to the buccinator muscle .

2 . Its contraction does not displace the lower denture so flanges of the lower denture must extend in the buccal vestibule.

Buccal Frenum

Denture Bearing and Limiting Structures (Lower)

1 . It is a fold of mucous membrane in the premolar area, movement of the lip and the cheek move the frenum .

2 . A notch is made in the lower denture to accommodate the frenum.

Buccal Frenum

Labial Vestibule

Labial Frenum

Denture Bearing and Limiting Structures (Lower)

Labial Frenum

Labial Vestibule

Residual Ridge

Denture Bearing and Limiting Structures (Lower)

Residual Ridge

Lingual Pouch

Denture Bearing and Limiting Structures (Lower)

More posteriorly the lingual flanges are related to the lingual pouch with its boundaries which are : Posteriorly : The palatoglosssus muscle . Anteriorly : The Mylohyoid muscle. Medially : The tongue . Laterally : The medial aspect of the mandible.

Lingual Pouch

Sublingual salivarygland area

Denture Bearing and Limiting Structures (Lower)

Sublingual salivarygland area

The lingual flanges of the lower denture should not extend in this area because with excessive resorption of the mandible the gland maybulge superiorly above the body of the mandible.

Lingual Frenum

Denture Bearing and Limiting Structures (Lower)

Lingual Frenum

1 . More anteriorly a fold of mucous membrane attach the mucosa of the tongue to mucosa of the floor of the mouth

2 . It moves with the movement of the tongue so a notch is made to accommodate the frenum.