State the types of bone density
Misch classified bone density into following types (1988)
D1. Dense cortical bone- which is almost never observed in maxilla and approximately 8% of time in mandible , where twice as often in anterior mandible than the posterior mandible.
D2. Dense to thick porous cortical bone on the crest and coarse trabecular bone within. It is the most common density observed in mandible and is less often in maxilla, where it is more likely to occur in partially edentulous patient's anterior and premolar region.
D3. Very common in maxilla followed by posterior mandible and then anterior mandible
D4. The softest bone, is most often found in the posterior maxillae, especially in molar region or after a sinus graft augmentation. Anterior maxilla has D4 bone less than 10% of time and mandible less than 3%