ANATOMICAL LANDMARKS IN MANDIBULAR IMPRESSION ANTOMICAL LANDMARK a

ANATOMICAL LANDMARKS IN MANDIBULAR IMPRESSION.

ANTOMICAL LANDMARK “ a recognizable anatomic structure used as a point of reference. ” GPT-8 In both maxilla and mandible anatomic landmarks has been divided in-supporting structures -peripheral or limiting structure

LIMITING STRUCTURES Labial frenum Labial vestibule Buccal frenum Buccal vestibule Lingual frenum Alveolingual sulcus Retromolar pads

RELIEF AREA Mylohyoid ridge Mental formen Genial tubercles Torus mandibularis

MANDIBULAR SUPPORTING AREAS

RESIDUAL ALVEOLAR RIDGE - covered by keratinized layer and firmly attached to the periosteum - cancellous in nature, does not have a good cortical plate covering it Significance -hence it is a secondary relief area, usually relieved during

SLOPES OF RESIDUAL ALVEOLAR RIDGE - has thin plate of cortical bone Significance - because walls are steep and at an angle to occlusal forces, it is not suited for primary stress bearing, hence it is secondary stress bearing.

BUCCAL SHELF AREA Buccal shelf area - bounded by anteriorly – buccal frenum posteriorly – retromolar pad medially – crest of alveolar ridge laterally – external oblique ridg

SIGNIFICANCE ● ● buccal shelf area may be very wide and is at right angles to the vertical occlusal forces. For this reason it offers excellent resistance to such forces. hence considered as primary stress bearing area

RELIEF AREAS OF MANDIBLE

MYLOHYOID RIDGE bony ridge found on lingual side of the mandible - mylohyoid muscle is attached to this ridg - soft tissue usually hides the sharpness of the ridge, which can be found by palpation

SIGNIFICANCE - level, inclination and prominence vary widely between patients - thin, sharp mylohyoid ridge can result in soft tissue irritation when denture is placed over it. Surgical correction may be required - height of the lingual flange is determined by the mylohyoid ridge.

MENTAL FORAMEN ● ● This is of concern when the ridge is extremely resorbed Foramen is found near or on the ridge crest in premolar region significance In such cases it should be relieved

TORUS MANDIBULARIS rounded prominences found in some individuals ● located in the region of premolars, midway between soft tissues of the floor of the mouth and crest of the ridge significance -covered by a thin layer of mucous membrane which may be irritated by ●

GENIAL TUBERCLE ● ● These are pair of bony tubercles found anteriorly on the lingual side of the mandible. Due to resorbtion , it may become increasingly prominent making denture usage difficult