MDS PREP
Malformation of the coronal portion of the permanent anterior teeth is most frequently encountered in the
1. maxillary central incisor
2. maxillary lateral incisor
3. maxillary canine
4. mandibular lateral incisor
Dental Anatomy
Answer: 2
Maxillary lateral incisor agenesis:
This is the most common congenital absence of a permanent tooth in the maxillary
anterior region, accounting for about 20% of all dental anomalies.
Coronal developmental invagination (DI):This is a common anomaly in the
permanent maxillary lateral incisor, usually appearing as an accentuation of the
lingual pit.It's often bilateral.
Peg-shaped crown:This is a common alteration in the maxillary lateral incisor.
The first teeth to erupt in the dental arches of the human being are the, primary
1. mandibular cuspids
2. maxillary central incisors.
3. mandibular central incisors
4. maxillary first molars
Dental Anatomy
Answer: 3
The first teeth to erupt in the dental arches of the human being are the, primary mandibular central incisors
Primary teeth begin to calcify between the ________ and ________months in
utero.
1) first; second
2) second; fourth
3) fourth; sixth
4) sixth; eighth
The primary teeth begin to form in utero at about six weeks. Hard tissue
formation occurs in all primary teeth by the 18th week in utero. 3. The
permanent teeth begin to develop at approximately four months of age in utero.
Maxillary and mandibular first molars begin to calcify at birth.
How many root canals does a madibular first molar normally have
1. 2
2. 3
3. 4
4. 5
Dental Anatomy
Answer: 2
madibular first molar normally have 3 root canals
How soon after the eruption of permanent tooth is the apex usually fully developed?
1. Immediately
2. 3-6 months
3. 2-3 years
4. 6-9 years
Dental Anatomy
Answer: 3
Afet tooth eruption in permanent teeth the apex is fully developed after 2-3 years
When extracting a primary maxillary incisor in which the root has been partially resorbed because of pres sure from its developing succe daneous tooth, which aspect of the remaining primary root will usually be longest and attached most securely to the gingiva?
1. Facial
2. Mesial
3. Lingual
4. Distal
Dental Anatomy
Answer: 1
In the case of primary teeth, the roots are often resorbed as the permanent teeth develop. The facial aspect of the root tends to be the last area to undergo resorption due to its position and the way the succedaneous tooth exerts pressure. The facial root surface is generally more stable and remains attached to the gingiva longer than the other aspects, making it the longest and most securely attached during extraction.
The smallest and most inaccessible root canal-in the maxillary second molar is the
1. faciolingual
2. mesiobuccal
3. lingual
4. distobuccal
Dental Anatomy
Answer: 4
The smallest and most inaccessible root canal-in the maxillary second molar is the distobuccal
When calcospherites fail to fuse during calcification of dentin matrix then
1 Interglobular dentin is formed
2 Dead tracts are found in formed dentin
3 Irregular dentin results
4 None
Dental Anatomy
Answer: 1
Sometimes, mineralization of dentin begins in small globular areas that fail to coalesce into a homogenous mass. This results in zones of hypomineralization between the globules.
These zones are known as globular dentin or interglobular spaces. Thus, demonstrating defect of mineralization and not of matrix formation, the dentinal tubules pass uninterruptedly through interglobular dentin.