MDS PREP
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
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.
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
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
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
A mandibular primate space is usually found in the primary dentition between
1. first and second molars
2. central and lateral incisors
3. lateral incisor and canine
4. canine and first molar
Dental Anatomy
Answer: 4
A mandibular primate space is usually found in the primary dentition between canine and first molar
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.
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.