Quiz 2, 3, 8

Question 1

What line separates the enamel from the cementum of the tooth?

Answer 1

The anatomic line separating enamel from cementum on the tooth is the cementoenamel junction.

Question 2

How could a portion of the anatomic crown be a part of the clinical root?

Answer 2

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

Question 3

How many roots are present in a trifurcated and in a bifurcated tooth?

Answer 3

A trifurcated tooth has three roots; a bifurcated tooth has two roots.

Question 4

Are maxillary teeth upper or lower jaw teeth?

Answer 4

Maxillary teeth are located in the upper jaw. Mandibular teeth are located in the lower jaw.

Question 5

Which tooth tissue composes the bulk of the tooth?

Answer 5

Dentin composes the bulk of the tooth because it makes up the majority of the crown and root portions.

Question 6

Which tooth tissue is the hardest?

Answer 6

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.

Question 7

Which tooth tissue is the softest?

Answer 7

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.

Question 8

Which tooth tissues have their own nourishment system?

Answer 8

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.

Question 9

Which tooth tissue is most like bone?

Answer 9

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.

Question 10

What is the main nourishment system of the tooth?

Answer 10

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.

Question 11

Name the different parts of the pulp cavity

Answer 11

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.

Question 12

Is the pulp horn a part of the pulp chamber or the pulp canal?

Answer 12

The pulp horn is the cusp of the pulp chamber.

Question 13

What does the pulp tissue comprise?

Answer 13

The pulp tissue is composed of blood vessels (arteries and veins), lymph vessels, connective tissue, nerve tissue, and odon

Question 14

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

Answer 14

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

Question 15

What is the difference between the alveolus and the alveolar process?

Answer 15

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.

Question 16

Which is seen in the mouth first, the clinical or anatomic crown?

Answer 16

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.

Question 17

What is the percentage of inorganic material in enamel? In dentin? In cementum?

Answer 17

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.

Question 18

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?

Answer 18

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.

Question 19

What are the basic functions of the teeth? What determines which functions each tooth has?

Answer 19

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.

Question 20

What are the longest teeth in human dentition? Why are they considered the longest? How do the maxillary and mandibular compare?

Answer 20

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.

Question 21

Why is the term bicuspid inaccurate compared with premolar?

Answer 21

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.

Question 22

What is the function of the molars, and how do the cusps perform this function?

Answer 22

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.

Question 23

How many premolars and how many molars are there in permanent dentition?

Answer 23

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.

Question 24

How many surfaces are on a posterior tooth? Name them.

Answer 24

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).

Question 25

Which proximal surface is farther away from the midline, and which is closest to the midline?

Answer 25

The mesial surface of a tooth is toward the midline and the distal surface is farther away from the midline of the mouth.

Question 26

If the anterior teeth do not have a fifth surface, what do they have that replaces the fifth surface?

Answer 26

Anterior teeth do not have an occlusal surface; instead, they have an incisal ridge that is the biting edge.

Question 27

What is a line angle? Name the six line angles for the anterior teeth and the eight for the posterior teeth.

Answer 27

A line angle forms the junction to separate two surfaces of a tooth. The proximal surface is listed first and the incisal/occlusal surface listed last. The anterior teeth have six line angles: distolabial, mesiolabial, distolingual, mesiolabial, labioincisal, and linguoincisal. Posterior teeth have eight line angles: distobuccal, mesiobuccal, distolingual, mesiolingual, disto-occlusal, mesio-occlusal, bucco-occlusal, and linguo-occlusal.

Question 28

What is a point angle?

Answer 28

A point angle is the point where three tooth surfaces meet. They are named first by the interproximal surface, then facial/lingual, and the incisal/occlusal surface is listed last.

Question 29

The developmental grooves separate the lobes of a tooth. How many lobes does an anterior tooth have?

Answer 29

Anterior teeth have four lobes separated by two developmental grooves on their labial surface. These developmental grooves separate the three labial lobes of the teeth. The fourth lobe is the lingual lobe on the lingual surface.

Question 30

What separates the cingulum on an anterior tooth from the labial lobes?

Answer 30

The cingulum is formed by the fourth developmental lobe on anterior teeth. The lingual fossa separates the fourth lobe from the labial lobes. This lingual fossa may be a singular fossa or two fossae interrupted by a tubercle.

Question 31

What is the small elevation of enamel on some portion of the crown of a tooth?

Answer 31

A small elevation of enamel on some portion of the crown of a tooth is called a tubercle.

Question 32

What is the small pinpoint depression that occurs along a developmental groove?

Answer 32

A small pinpoint depression along a developmental groove is called a pit.

Question 33

Explain the difference between a tubercle and a cusp.

Answer 33

A tubercle is a small elevation of enamel on any portion of a crown of a tooth. A cusp is a mound on tooth's crown that makes up a large portion of the tooth's occlusal surface.

Question 34

Empty swimming pool

Answer 34

Concave

Question 35

Empty soup bowl

Answer 35

Concave

Question 36

Cave

Answer 36

Concave

Question 37

Ridge of a mountain

Answer 37

Convex

Question 38

Cusp tip

Answer 38

Convex

Question 39

Valley between two hills

Answer 39

Concave

Question 40

A marginal ridge

Answer 40

Convex

Question 41

Lingual fossa of an anterior tooth

Answer 41

Concave

Question 42

Explain the difference between a developmental groove and a pit.

Answer 42

A developmental groove is a shallow groove or line that separates primary parts of a tooth's crown or root. A pit is a pinpoint depression that typically occurs along a developmental groove at its deepest part.

Question 43

The developmental elevated rounded mound of the crown that forms a major division of the occlusal surface is a

Answer 43

A cusp is a mound on tooth's crown that makes up a large portion of the tooth's occlusal surface.

Question 44

A developmental elevated projection on the lingual surface of a newly erupted incisor is a

Answer 44

A cingulum is an elevated projection on the lingual surface of a newly erupted incisor.

Question 45

If a maxillary central incisor has an almost transparent incisal edge and a maxillary lateral incisor has a very white line covering its incisal edge, which incisor is more mineralized at its incisal edge?

Answer 45

The central The more mineralized the enamel is, the more translucent it appears. Age and skin pigmentation also affect the coloring of enamel. White spots are evidence of incomplete mineralization.

Question 46

What type of specialized cells form dentin?

Answer 46

Dentin is formed by specialized cells called odontoblasts.

Question 47

Which type of cementum is part of the system that anchors the tooth to the bone?

Answer 47

Acellular cementum's primary function is to be part of the attachment system of the tooth. Acellular cementum has Sharpey's fibers embedded in it to anchor the tooth in bone.

Question 48

Name the two types of cementum.

Answer 48

The two types of cementum are cellular cementum and acellular cementum.

Question 49

What types of dentin form in response to deep tooth decay?

Answer 49

Tertiary (reparative) dentin forms in response to different forms of trauma to a tooth, like deep decay.

Question 50

What normally fills the interproximal spaces between teeth? If this is missing, what is the void called?

Answer 50

The interproximal spaces between teeth are normally filled with gingival tissue called papillary gingiva. When the interproximal gingival is missing, the void is called the cervical or gingival embrasure

Question 51

Name the embrasures and explain their function. Which embrasure is not always present and why?

Answer 51

Embrasures allow food to be shunted away from contact areas; reduce the trauma of occlusal forces on teeth; provide a round, smooth surface for self-cleaning; and allow food to slightly provide frictional massage to the gingival tissues. Embrasure spaces are named based on their location: facial (buccal or labial), lingual, incisal or occlusal, and gingival. The gingival embrasure, also called the cervical embrasure, is not usually present; it is only present if the interproximal space is not occupied by bone and gingiva.

Question 52

Which teeth have the greater curvature of the cementoenamel junction, anterior or posterior? Mesial or distal?

Answer 52

The crowns of anterior teeth show greater curvature of the cementoenamel junction that do posterior teeth. The mesial curvature on anterior teeth is greater than the distal curvature on that same tooth. On posterior teeth, the mesial curvature is about 1 mm; the distal curvature is nearly nonexistent.

Question 53

What terms are synonymous with the cementoenamel junction?

Answer 53

The cementoenamel junction is also called the cervical line.

Question 54

Explain how the diet a person chooses has an effect on gingival and tooth health

Answer 54

Primitive people, by eating natural raw foods, wore down some of the enamel of their teeth in the process of chewing, which resulted in the gradual obliteration of the pits and fissures. Our diet of soft, overcooked, tacky, and sticky foods has resulted in an inability to wear down enamel; additionally, the stickiness of the food allows it to adhere to the tooth surface even when pits and fissures are not present.

Question 55

What happens if a tooth is restored so that it has an overhanging restoration?

Answer 55

Overhanging restorations occur when a tooth is restored and the restorative material extends too far beyond the tooth. These restorations harbor bacteria, plaque, and food debris and create difficulty with proper oral hygiene practices.

Question 56

What happens if two adjacent teeth have open contact areas?

Answer 56

If two adjacent teeth have open contact areas, food debris in able to impact in the area. This will cause bacteria to accumulate and can lead to inflammation and breakdown of periodontal structures. A very large space is called a diastema and is so large that food does not cause an impact. This diastema is not an open contact. Open contacts are very small.

Question 57

What is the difference between a contact area and a contact point?

Answer 57

Contact areas of the teeth are the areas on the proximal surfaces of the teeth where one proximal surface touches another. A mesial contact area of a mandibular first molar touches the distal contact area of a mandibular second premolar. A contact point differs from a contact area. A contact point is where the occlusal cusp of one tooth touches the occlusal portion of another tooth in the opposing arch. The contact point is where the cusp of a maxillary tooth touches the mandibular tooth. This is the place where one tooth hits the other when closing the teeth together.

Question 58

Which of the following spaces present the greatest potential for food impaction, periodontal disease, and caries?

Answer 58

Interproximal space distal to the maxillary first molar The interproximal space distal to the maxillary first molar is the most likely to create food impaction. The long vertical contact area between the maxillary first and second molar is much harder to keep clean than the space mesial to the first molar. The large edentulous area does not allow food impaction.

Question 59

The buccal crest of curvature is ______________ the buccal height of contour.

Answer 59

the same as The buccal crest of curvature is the same as the buccal height of contour. The crest of curvature refers to the widest part of the crown of the tooth; it is the same as the height of contour.

Question 60

What is the normal amount of crest of curvature?

Answer 60

The crest of curvature averages 0.5 mm on the facial surfaces and on the lingual surfaces of maxillary posterior teeth. The crest of curvature is slightly less than 0.5 mm on the lingual surfaces of maxillary posterior teeth. The crest of curvature on the lingual side of posterior teeth is located in the middle third of the crown.

Question 61

While examining this patient, you notice an open contact between the two mandibular premolars. What are your concerns?

Answer 61

The first concern is if food could be trapped between these two teeth. This space is too large to trap food. Most food would pass right through and not cause a periodontal problem. A space much smaller than this could be a problem. This space is actually a primate space found naturally in most primates (refer to Chapter 6).

Question 62

Which of the following are true of attached gingiva?

Answer 62

b. The epithelial layer is thick and keratinized, c. The tissue can have a stippled texture, and d. The tissue is fixed and firmly attached to the bone and cementum. The attached gingiva is highly keratinized and covered by stratified squamous epithelium. The attached gingiva often displays a stippled texture. The attached gingiva is immobile and firm. The tissue is fixed and firmly attached to the bone and cementum.

Question 63

Which is most true of cementum?

Answer 63

a. Sharpey's fibers are embedded in it. Sharpey's fibers embed in bone and cementum. Cementum is a hard, bone-like tissue that covers the roots of the teeth. Acellular cementum covers the cervical third of the root and extends over almost the entire root except the apical portion where it is replaced or covered over with cellular cementum. It is more resistant than bone to pressure.

Question 64

Which is true of Sharpey's fibers?

Answer 64

c. They can embed in either bone or cementum, d. The same fiber could embed in bone at one end and in cementum at the other. Sharpey's fibers embed firmly into bone and cementum. It would be extremely rare for it to be in dentin. Some Sharpey's fibers embed in bone or cementum at one end and run horizontally, obliquely, or apically from the tooth to the bone and function to hold the tooth in the bony socket.

Question 65

Rete peg formation

Answer 65

Rete pegs are extensions of stratified squamous epithelium that covers the attached gingiva. These fibers extend deep into the connective tissue and create more surface area for the tissue to attach and receive nutrients. They also create the stippled (dimple) appearance of the attached gingiva.

Question 65

When the tooth is subjected to occlusal stress, it relieves this stress by which of the following mechanisms?

Answer 65

a. The periodontal ligament tenses, b. The fluids in the periodontal ligament absorb some force, and c. The walls of the alveolus spread the force out and divide it over a wider area. As the periodontal ligament (PDL) stretches and tenses in response to pressure, this tension resists and combats these forces. The fluids in the PDL have a shock absorption function to relieve stress on the tooth and PDL fibers. PDL fibers compress and stretch to allow the tooth to move within the body socket. The PDL fibers distribute occlusal forces evenly within the bony socket.

Question 66

Stratified squamous epithelium

Answer 66

The most common of the multiple-layered epithelia; found as skin and mucosa

Question 67

The alveolar bone when seen on the x-ray is called lamina dura.

Answer 67

True. When viewed radiographically, the alveolar bone proper is called the lamina dura.

Question 68

The gingival papilla is located in the interdental space.

Answer 68

True. The gingival papilla (interdental papilla) is the free gingiva located in the triangular interdental spaces.

Question 69

The gingival sulcus is the space between the tooth and the mucogingival fold.

Answer 69

False. The gingival sulcus is the space between the free gingiva and the tooth

Question 70

The attached gingiva extends from the gingival sulcus to the interdental space.

Answer 70

False. The attached gingiva extends from the base of the sulcus and is attached to the bone and the cementum by a dense network of collagenous fibers. It extends in the opposite direction than above.

Question 71

The free gingiva extends from the gingival margins to the base of the gingival sulcus.

Answer 71

True. Free gingiva is the gum tissue that extends from the gingival margin to the base of the gingival sulcus it is also called marginal gingiva.