Development And Eruption Of Teeth Question And Answers

Development And Eruption Of Teeth

Question 1. What is a chronology of deciduous dentition?
Answer:

Chronology of deciduous dentition.

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1. Calcification of primary teeth:

• It begins in utero from 13-16 weeks post-fertilization.
• By 18-20 weeks, all the primary teeth have begun to calcify.
• The first indication of tooth formation occurs as early as the sixth week of prenatal life when the jaws have assumed their initial shape.

2. Crown formation:

• Primary tooth crown formation takes only some 2 completion.

3. Eruption/emergence of primary teeth:

• The emergence of primary dentition takes place between the sixth and thirtieth months of postnatal life.
• It is an important time for the development of oral motor behavior and the acquiring masticator skills.
• After the crown and part of the root are formed, the tooth penetrates the alveolar gingiva and emerges into the mouth.
• The process of eruption is completed when most of the crown has emerged and when it has made contact with its antagonist or antagonists in the opposing jaw.
• The root formation is not complete at this stage.

4. Sequence of the emergence of primary teeth:

• The sequence of eruption of the primary teeth in the individual jaw is.
  1. Central incisor (A)
  2. Lateral incisor (B)
  3. First molar
  4. Canine
  5. Second molar (E)
• The mandibular central incisors emerge first through the alveolar gingiva, followed by the other anterior teeth by about 13-16 months except for canines.
• Then the first primary molars emerge by about 16 months of age and make contact with opposing teeth several months later before the canines have fully erupted.
• The maxillary molar erupts earlier than the mandibular molar.
• The primary maxillary canines erupt at about 19 months while mandibular canines at 20 months.
• Lastly, the primary second mandibular molar erupts at a mean age of 27 months, and the primary maxillary second molar at 29 months.

5. Root completion:

• After the crown of the tooth is formed development of the root portion begins.
• At the cervical border of the enamel, the cementum starts to form as a root covering the dentin.
• Root formation is an active factor in moving the crown toward its final position in the month.
• The formation of root dentin and cementum continues after the tooth is in use.
• The root is completed with a complete covering of momentum.

Question 2. The sequence of the eruption of deciduous teeth.
Answer:

The order of eruption of deciduous teeth is as follows:

A B D C E

• Lower central incisor
• Upper central incisor
• Lower lateral incisor
• Upper lateral incisor
• First molars
• Canines
• Second molars.

The first tooth starts erupting at 62 months and the last tooth by 3 years.

Question 3. The sequence of the eruption of permanent teeth.
Answer:

• The order of eruption of upper permanent teeth.

6 1 2 4 5 3 7 8

• The order of eruption of lower permanent teeth

6 1 2 3 4 5 7 8

• The order of permanent teeth is as follows.
• First molars
• Lower central and lateral incisors
• Upper centrals
• Upper laterals
• Lower canines
• First premolars
• Second premolars
• Upper canines
• Second molars
• Third molars.

Question 4. Define eruption and shedding.
Answer:

• Eruption was used to denote the tooth’s emergence through the gingiva.
• Then, it becomes more completely defined to mean continuous tooth movement from the dental bud to occlusal contact.

Shedding:

• The physiologic process resulting in the elimination of the deciduous dentition is called shedding or exfoliation.

Question 5. Dental anomalies.
Answer:

• Dental anomalies results when disturbances in the form, color, arrangement, and structure of the teeth might have occurred.

Teeth affected:

• Third molars, maxillary lateral incisors, mandibular second premolars.

Results:

• Restorative problems in peg-shaped laterals
• Spaces problems – in mandibular second premolars with two lingual cusps.
• Quantitative defects of enamel thickness in enamel hypoplasia.
• Qualitative defects in hypo calcification.
• Cleft lip and palate.
• Screwdriver-shaped central incisor and mulberry molars – in congenital syphilis.

Question 6. Chronology of permanent dentition
Answer: