Quiz 2, 3, 8 Flashcards
(72 cards)
What line separates the enamel from the cementum of the tooth?
The anatomic line separating enamel from cementum on the tooth is the cementoenamel junction.
How could a portion of the anatomic crown be a part of the clinical root?
The clinical crown is the portion of the tooth visible in the mouth; the clinical root is the portion of tooth not visible in the mouth and covered by bone and gingival tissue. The anatomic crown is the portion of tooth covered by enamel; the anatomic root is the portion of the tooth covered with cementum. If a portion of the anatomic crown of the tooth is covered by gingival tissue, it would be part of the clinical root.
If a tooth is not completely erupted, that part of the anatomic crown that is still under the gum is considered the clinical root. The clinical root is any part of the tooth as yet unerupted under the gum, no matter what part of the tooth it is
Gum recession
How many roots are present in a trifurcated and in a bifurcated tooth?
A trifurcated tooth has three roots; a bifurcated tooth has two roots.
Are maxillary teeth upper or lower jaw teeth?
Maxillary teeth are located in the upper jaw. Mandibular teeth are located in the lower jaw.
Which tooth tissue composes the bulk of the tooth?
Dentin composes the bulk of the tooth because it makes up the majority of the crown and root portions.
Which tooth tissue is the hardest?
Enamel is the most dense and hardest tissue in the human body. It is composed of 96% inorganic matter and 4% organic matter and water.
Which tooth tissue is the softest?
Pulp is the soft tissue of the teeth; it is composed of blood and lymph vessels, nerve and connective tissues, and odontoblasts. Enamel, cementum, and dentin are all hard tissues of the teeth. Of these three hard tissues, enamel is the hardest and most dense, and cementum is the least dense of the hard tissues.
Which tooth tissues have their own nourishment system?
Cementum is separated from the tooth’s self-nourishment system; instead, the nutrition for cementum is derived from the outside of the tooth through blood vessels that come directly from the bone. Pulp has its own nourishment, blood vessels and nerves. The dentin is laid down on the inside of the tooth. Its odontoblasts are nourished by the pulpal tissues. Once enamel is formed and laid down it has no nourishment system.
Which tooth tissue is most like bone?
Cementum has a strong physiologic resemblance to bone, although it is denser than bone. It is composed of 45%- 50% inorganic and 50%-55% organic matter.
What is the main nourishment system of the tooth?
The pulp supplies the nourishment system for the tooth (except for the cementum). Pulp tissue contains blood vessels which bring nourishment and white blood vessels to fight infection.
Name the different parts of the pulp cavity
The pulp cavity consists of the pulp chamber, pulp horns, and pulp canal. The pulp chamber rests in the crown of the tooth; the cusps of the chambers are the pulp horns. The pulp canal is contained within the root portion of the tooth.
Is the pulp horn a part of the pulp chamber or the pulp canal?
The pulp horn is the cusp of the pulp chamber.
What does the pulp tissue comprise?
The pulp tissue is composed of blood vessels (arteries and veins), lymph vessels, connective tissue, nerve tissue, and odon
The root-to-crown ratio is determined by dividing the length of ____ by the length of ____. How does this affect a tooth’s resistance to displacement
The root-to-crown ratio is determined by dividing the length of the root by the length of the crown. Almost all teeth have longer roots than crowns, so the root-to-crown ratio is almost always 1 or higher than 1. The higher the root-to-crown ratio number, the more resistant the tooth will be to displacement
What is the difference between the alveolus and the alveolar process?
The alveolar process is the portion of alveolar bone that supports the teeth. The alveolus is the bony socket within the alveolar process where the tooth fits.
Which is seen in the mouth first, the clinical or anatomic crown?
The clinical crown is that portion of the tooth crown that is visibly seen in the mouth first. It not covered by soft gingival tissues. The clinical crown will become larger as the tooth erupts into the mouth and can include the part of the root if that part of the root is not covered by gingival tissue. The anatomic crown is that portion of the tooth that is covered by enamel; it cannot be changed.
What is the percentage of inorganic material in enamel? In dentin? In cementum?
Enamel is composed of 96% inorganic matter and 4% organic matter and water. Dentin is made of 70% inorganic matter and 30% organic matter and water. Cementum is composed of 45% to 50% inorganic and 50% to 55% organic matter.
Enamel is harder than dentin, and dentin is harder than cementum. How does this correlate to the percentages of inorganic versus organic materials present in these tissues?
Enamel has more inorganic matter than dentin; dentin has more inorganic matter than cementum. The more inorganic matter component in a tooth tissue, the harder that tooth tissue will be.
What are the basic functions of the teeth? What determines which functions each tooth has?
The basic functions of teeth are to begin processing food by cutting, holding, and grinding. The individual tooth function varies by specific tooth shape and location in the mouth. The incisors cut food and shovel it back into the mouth, the canines hold and tear food, the premolars help hold and grind food, and the molars crush and grind food.
What are the longest teeth in human dentition? Why are they considered the longest? How do the maxillary and mandibular compare?
The canines are the longest teeth in the human dentition. They are the most stable teeth because they have the longest roots of all teeth. The maxillary canines have the highest root-to-crown ratio of all the teeth and the least susceptible to forces of displacement.
Why is the term bicuspid inaccurate compared with premolar?
The term bicuspid is sometimes used to refer to premolar teeth. The term bicuspid implies that the tooth has only two cusps; this is inaccurate because some premolars have three cusps on their occlusal surfaces.
What is the function of the molars, and how do the cusps perform this function?
The molars function to chew and grind up food. The cusps of the maxillary molars interlock with the mandibular molars. This interlocking mechanism creates a crushing and grinding function.
How many premolars and how many molars are there in permanent dentition?
There are 8 premolars in the permanent dentition, 4 maxillary and 4 mandibular, 2 on each side of the mouth. There are 12 molars in the permanent dentition: 6 maxillary and 6 mandibular, 3 on each side of the mouth.
How many surfaces are on a posterior tooth? Name them.
There are five surfaces on posterior teeth: lingual (toward the tongue), buccal (toward the cheek), mesial (toward the midline), distal (away from the midline), and occlusal (the chewing surface).