MDS PREP
The secretory product of odontoblasts is:
1) Topocollagen.
2) Calcium salts.
3) Mantle dentin.
4) Hydroxyapatite
Dental Anatomy
Answer: 3
Dentinogenesis is the formation of dentin by odontoblasts of mesenchymal origin
located at the periphery of the dental pulp
Dentinogenesis is initiated by the inductive influence of the enamel organ
involving molecular signaling pathways, such as Wnt, Runx-2, and TGF-?. In the
molar tooth, dentinogenesis starts at the late bell stage, and occurs in the
crown as well as root regions.
Predentin, the first organic matrix secreted by odontoblasts, is composed by
proteoglycans, glycoproteins, and collagens.
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.
If a 4th root canal is present in a maxillary 1st molar, it will likely be located in which of the following roots?
1) Mesiolingual
2) Mesiobuccal
3) Distolingual
4) Distofacial
Dental Anatomy Answer: 2
Well over 50% of maxillary 1st molars have two canals in the mesiobuccal root. Some authors cite the number as high as 90%.
There are usually 3 roots and 4 canals in a maxillary 1st molar.
The fourth canal, the mesiolingual canal, is also referred to as: the accessory mesiobuccal canal, mesiocentric, mesiopalatal canal or MB2.
It is usually tough to find MB2 through clinical inspection and it is not obvious on a radiograph. A dentist should expect it is present before beginning a root canal on the first maxillary molar.
The average overall length of the permanent maxillary central incisor is
1. 14.5mm
2. 18.0 mm
3. 22.5 mm
4. 30 mm
Dental Anatomy
Answer: 3
The average overall length of the permanent maxillary central incisor is 22.5 mm
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.
Which of the following permanent maxillary molar teeth normally has four root canals?
1. First molar
2. Second molar
3. Third molar
4. None of theabove
Dental Anatomy
Answer: 1
permanent maxillary First molar teeth normally has four root canals
The largest and longest root canal of the maxillary second molar is the
1. lingual
2. mesiobuccal
3. distobuccal
4. distal
Dental Anatomy
Answer: 1
The largest and longest root canal of the maxillary second molar is the lingual
In an average child the mixed dentition period is from
1. 10 years to 25 years
2. 4 yrs to 12 yrs
3. 8 yrs to 17 yrs
4. 6 yrs to 13 years
Dental Anatomy
Answer: 4
In an average child the mixed dentition period is from 6 yrs to 13 y