Other Physical Abnormalities
Tooth Wear

Attrition -  caused by a gritty diet and subconscious tooth-grinding
Abrasion - caused mainly by vigorous brushing in modern populations, the tooth surface becomes highly polished
Erosion - more of a modern problem due to over-exposure to acid, examples
These all cause the teeth to more susceptable to infection and sometimes fracture.

dead fracture
Courtesy: www.eastman.acl.ac.uk/climages/
Tooth Fractures often lead to tooth death and can lead to loss of the tooth. When the root tissue dies, the tooth will become discolored. (Cawson 1998)

Courtesy: www.eastman.acl.ac.uk/climages/
Severe malocclusion can interfere with an individual processing enough food for survival.

Courtesy: www.mshc.org.au/professional/content_prof.cfm
Congenital syphilis causes Hutchinson's teeth, characterized by incisors with a notched edge, and peg-shape (Cawson 1998)