BIO 357 Lecture Notes - Lecture 16: Periodontal Fiber, Fish Scale, Cementum
Document Summary
Once a tooth comes out of the gum, no more enamel will be added to it. Cementum- unorganized bone that holds the tooth in place. Occlusal surface- the chewing surface on teeth. The labial surface faces out, towards the lips. The lingual surface faces the tongue and the inside of the mouth. Cusps on upper teeth are called cones. Cusps on lower teeth are called conids. Luph- cusps fuse to form a ridge or a crest. All of the teeth look the same. Heterodont- the teeth throughout the mouth are different. There are four different kinds of teeth. The cusp of the last premolar on the top and the first molar on the bottom are good for shearing/cutting. Number of roots that the teeth have. Incisors and canines only have 1 root. Lower molars have 2 roots (primitive condition) Tribosphenic molars- triangularly configured cusps to cut/shear food into small pieces. Living marsupials and insectivores retain basic tribosphenic molars.
