Group 2
Introduction • Residual ridge:– shape of the clinical alveolar ridge after healing of bone and soft
tissues following tooth extraction• The size of the residual ridge is reduced most rapidly in
the first six months, but the bone resorption activity of the residual ridge continues throughout life at a slower rate, resulting in removal of a large amount of jaw structure.
• Residual ridge remodeling affects the function of removable prostheses, which rely greatly on the quantity and the architecture of jaw bones.
Classification of Residual Ridge Morphology
Type A (most favourable)
• Anterior labial and posterior buccal vestibular depth that resists vertical and horizontal movement of the denture base.
• Palatal morpholog resists vertical and horizontal movement of the denture base.
• Sufficient tuberosity definition to resist vertical and horizontal movement of the denture base.
• Hamular notch is well defined to establish the posterior extension of the denture base.
• Absence of tori or exostoses
Type A maxillary residual ridge
Type B
• Loss of posterior buccal vestibule.• Palatal vault morphology resists vertical and
horizontal movement ofthe denture base.• Tuberosity and hamular notch are poorly
defined, compromising delineation of the posterior extension of th
• Maxillary palatal tori and/or lateral exostoses are rounded and do not affect the posterior extension of the denture base.
Type B maxillary residual ridge
Type c• Loss of anterior labial vestibule.• Palatal vault morphology offers minimal resistance to
vertical and horizontal movement of the denture base.• Maxillary palatal tori and/or lateral exostoses with bony
undercuts that do not affect the posterior extension of the denture base.
• Hyperplastic, mobile anterior ridge offers minimum support and stability of the denture base.
• Reduction of the post malar space by the coronoid process during mandibular opening and/or excursive movements.
Type C maxillary residual ridge
Type D
• Loss of anterior labial and posterior buccal vestibules.
• Palatal vault morpholoa does not resist vertical or horizontal movement of the denture base.
• Maxillary palatal tori and/or lateral exostoses“ (rounded or undercut) that intcrferc with the posterior border of the denture.
• Hyperplastic, redundant anterior ridge.• Prominent anterior nasal spine
Type D maxillary residual ridge
List of morphological changes of completely edentulous state regarding aesthetic
• Deepening of nasolabial groove• Loss of labiodental angle• Decrease in horizontal labial angle• Narrowing of lips• Increase in columella-philtral angle• Prognathic appearance