Undercut
Defintion
( \Un´dur-kUt\ n (1859) )
1: the portion of the surface of an object that is below the height of contour in relationship to the path of placement
2: the contour of a cross-sectional portion of a residual
ridge or dental arch that prevents the insertion of a dental prosthesis
3: any irregularity in the wall of a prepared tooth that prevents the withdrawal or seating of a wax pattern or casting
Undercut Management
Leave It
Outside denture area ...
Reduce distolingual length ...
Utilize It
If less than 180 degree ...
Unilateral ...
Rotational path of insertion ...
Relief
For one of the bilateral undercuts ...
Surgical Correction
Soft tissue corrections….etc
Bone shaping….etc
The use of implant retained fixed dentures
Without flanges ...
Causes
Developmental
Mandibular tori….etc
Soft Tissue Disease
Fibromatosis ...
Soft tissue tumor….etc
Bone Disease
Bone exostosis ...
Bone tumor….etc
Post Extraction Problems
Uncompressed socket …etc
Aging Changes
Interior oblique ridge prominence ...
Genial tubercle prominence ...
Tuberosity with pneumenization of maxillary sinus air cells….etc
Undercut Shape Images
Localized
Generalized
denture fibroma