Question 1

Which tooth's crown in the primary dentition does not resemble any other crown of either dentition?

Accepted Answer

The crown of the maxillary first molar does not resemble any other crown of either dentition.The maxillary second molar most closely resembles the form of the permanent maxillary first molar but is smaller in all dimensions.The crowns of both the primary maxillary and mandibular canines resemble that of their permanent counterparts,although some dimensions are different.

Question 2

Which of the following primary teeth has a relatively longer and sharper cusp than of its permanent successor when first erupted?

Accepted Answer

The crown of the primary maxillary canine has a relatively longer and sharper cusp than that of its permanent successor when first erupted.The crown of the primary mandibular canine resembles that of the primary maxillary canine,although some dimensions are different.Both primary lateral incisors do not have a cusp similar to that of their permanent counterparts but instead have only a cingulum like the canines.

Question 3

Approximately how many years do the primary molars need to function during either the primary or mixed dentition period?

Accepted Answer

There are eight primary molars,with two types,a first molar and second molar.One of each type is located in each quadrant of both dental arches.Both have the similar arch position,function,and general shape as the permanent counterpart,and they function as such for approximately 9 years.

Question 4

Which of the following features is found on a primary molar's crown as compared to the crown of a permanent molar?

Accepted Answer

In comparison to permanent molars,the crowns of primary molars are also more constricted,or narrower,at the cementoenamel junction,making them appear bulbous in comparison to the thinness of the tooth neck.The occlusal table is also narrower than the permanent counterpart.A prominent cervical ridge is present on both the labial and lingual surfaces of anterior teeth and on buccal surfaces of the molars,even more so than any similar structure on the even larger permanent molars.The contacts are broad and flat.

Question 5

How does the primary mandibular canine compare to its permanent counterpart?

Accepted Answer

The crown of the primary mandibular canine resembles that of the primary maxillary canine,although some dimensions are different.This tooth is much smaller labiolingually.The distal cusp slope is much longer than the mesial cusp slope,as is the case on its permanent counterpart.The lingual surface is smoother than the primary maxillary canine and is marked by a shallow lingual fossa.

Question 6

Which of the following features is found on a primary molar's pulp cavity as compared to the pulp cavity of a permanent molar?

Accepted Answer

The pulp cavity on primary teeth shows that both the pulp chambers and pulp horns are relatively large in proportion to those of the permanent teeth,especially the mesial pulp horns of the molars.The pulp horns are also closer to the outer surface,with the pulp chambers being shallow.

Question 7

Which of the following primary molars usually has a cusp of Carabelli present on its occlusal surface?

Accepted Answer

The primary maxillary second molar most closely resembles the form of the permanent maxillary first molar but is smaller in all dimensions.Thus,it usually has a cusp of Carabelli,the minor fifth cusp,as does its permanent counterpart.

Question 8

How many erupted primary teeth does a 3-year-old child usually have?

Accepted Answer

The primary dentition takes between 2 and 3 years to complete,beginning with the initial mineralization of the primary mandibular central incisors and ending with root formation in the primary maxillary second molar.

Question 9

Which of the following features can always be noted on the primary maxillary central incisors?

Accepted Answer

Unlike their permanent successors,the primary maxillary central incisors have no mamelons,leaving the labial surface smooth.In addition,these teeth rarely have developmental depressions or imbrication lines,and no pits are evident on the lingual surface.However,the cingulum and marginal ridges on the lingual surface all are more prominent than on the permanent successor,and the lingual fossa is deeper.Both proximal surfaces of the maxillary central incisor appear similar.

Question 10

Which of the following statements is correct concerning when a child's first dental appointment should occur?

Accepted Answer

A child's first dental appointment should occur within 6 months of the eruption of the first primary tooth and no later than 12 months of age.The intent of this recommendation is to provide information to the child's supervising adults,which will help to establish positive preventive behaviors,prevent serious dental problems,and allay concerns.

Question 11

Which of the following features is found on a primary molar's roots as compared to the roots of a permanent molar?

Accepted Answer

Roots of primary teeth are narrower mesiodistally and longer than the crown length.Each crown-to-root ratio of primary teeth is smaller than those ratios of their permanent dentition counterparts.Molar roots flare more as they approach the apex and the apical foramina may be larger,with the accessory canals often larger and more numerous.

Question 12

Child patients within the mixed dentition period and their supervising adults may not notice the presence of the newly erupted permanent _____ of either arch because,when it erupts,it appears just like a larger primary second molar that is adjacent to it.

Accepted Answer

Child patients within the mixed dentition period and their supervising adults may not notice the presence of the newly erupted permanent first molar of either arch because,when it erupts,it appears just like a larger primary second molar that is adjacent to it.These child patients and their supervising adults must be reminded that,to last a lifetime,these new posterior permanent teeth require home care oral hygiene and possibly enamel sealants applied to the occlusal surface.

Question 13

The crown of the primary mandibular central incisor looks more like the primary _____ than its permanent successor.

Accepted Answer

The crown of the primary mandibular central incisor looks more like the primary mandibular lateral incisor than its permanent successor or any other primary maxillary incisor.

Question 14

When does mineralization of the primary dentition begin during prenatal development?

Accepted Answer

Mineralization of the primary teeth begins in utero at 13 to 16 weeks.By 18 to 20 weeks during prenatal development,all of the primary teeth have started to mineralize.

Question 15

How long does the primary dentition generally function in esthetics,mastication,and speech for a child?

Accepted Answer

The primary dentition generally functions in esthetics,mastication,and speech for a child for only 5 to 12 years.

Question 16

Which of the following is a correct statement about primate spaces found during the primary dentition period?

Accepted Answer

Certain interproximal spaces between the primary teeth are considered normal in most child patients,because space is necessary for the proper alignment of the future permanent dentition.These spaces still may concern the supervising adults,who may need reassurance.These spaces are considered primate spaces,mainly involving spaces between the primary maxillary lateral incisor and canine,and also between the primary mandibular canine and first molar.

Question 17

Which of the following primary molars has an H-shaped groove pattern on its occlusal surface?

Accepted Answer

The primary maxillary first molar has an H-shaped groove pattern and three fossae: central,mesial triangular,and distal triangular.The central groove connects the central pit with the mesial pit and distal pit,at each end of the occlusal table.

Question 18

Which of the following complications are associated with extraction of primary molars?

Accepted Answer

The greater root spread of primary molars,along with their narrow shape and lack of root trunk,makes primary molars susceptible to fracture during extraction procedures.

Question 19

Which of the following must be suspected in a primary or mixed dentition if there is severe periodontal inflammation and destruction with evidence of little dental biofilm?

Accepted Answer

If severe periodontal inflammation and destruction in the primary or mixed dentition are found with evidence of little dental biofilm,either locally or generally,early aggressive periodontitis must be suspected (previously considered juvenile periodontitis).Early intervention with this severe yet uncommon periodontal disease can prevent further periodontal destruction.

Question 20

Which of the following features is noted concerning the hard dental tissue of a primary molar as compared to that of a permanent molar?

Accepted Answer

Overall,the dentin of the primary dentition is thinner than that of the permanent counterparts.However,the dentin thickness between the pulp chambers and the enamel is increased,especially in the primary mandibular second molar.The enamel is also relatively thin in comparison to permanent counterparts,but it has consistent thickness overlying the dentin of the crown.

Quiz 18: Primary Dentition