MDS PREP
A tooth makes its appearance in the oral cavity usually when
1. all of the crown is completed
2. all of the root is completed
3. one half of the root is completed
4. one half of the crown is completed
Dental Anatomy
Answer: 3
A tooth makes its appearance in the oral cavity usually when one half of the root is completed
The permanent anterior tooth most often missing congenitally is the
1. maxillary central incisor
2. mandibular central incisors
3. mandibular lateral incisors
4. maxillary lateral incisors
Dental Anatomy
Answer: 4
lateral incisor is most often missing congenitally
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
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
9 months of age, is the usual eruption time for
1. primary mandibular canines
2. primary maxillary canines
3. primary maxillary first molars
4. primary lower lateral incisors
Dental Anatomy
Answer: 4
9 months of age, is the usual eruption time for primary lower lateral incis
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.
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
Interglobular Dentin:
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.
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