Sources: American Heart Association. Heart Disease and Stroke Statistics - 2009 Update; CDC, Heart Disease and Stroke Prevention Addressing the Nation's Leading Killers, At A Glance, 2011. Heart disease and stroke are the first and fourth leading causes of death in the United States.
Your teeth are composed of four dental tissues. Three of themâenamel, dentin and cementumâare hard tissues. The fourth tissueâpulp, or the center of the tooth that contains nerves, blood vessels and connective tissueâis a soft, or non-calcified, tissue.
Human tooth - Anatomy. 1  Dental anatomy is a field of anatomy dedicated to the study of tooth structure. 2  The anatomic crown of a tooth is the area covered in enamel above the cementoenamel junction (CEJ) or neck of the tooth. 3  Humans usually have 20 primary (deciduous, baby or milk) teeth and 32 permanent (adult) teeth.