Week 7 Mani- Self correcting anomalies

Question 1

What are self correcting anomalies found in pre-dental period?

Answer 1

• Infantile swallowing
• Retrognathic md
• Anterior open bite

Question 2

How does pts mandible often appear from birth to eruption of 1st deciduous teeth?

Answer 2

Retrognathic mandible

• Md lateral sulcus lies posterior to mx lateral sulcus
• Upper gum pad protrudes

Question 3

What are causes of retrognathic mandible prior to eruption of teeth?

Answer 3

• Growth magnitude and duration greater for anterior maxilla than anterior md
• Upper anterior gum pad (intercuspid width) > lower anterior gum pad
• Mandibular undergoes largest amount of growth post-natally rather than prenatally.

Question 4

How is retrognathic md prior to eruption of teeth self corrected?

Answer 4

Within 6-7 months by downward and forward growth of md

Question 5

What are self correcting anomalies in primary dentition?

Answer 5

• Anterior deep bite
• Spacing
• Flush terminal plane
• Edge to edge bite

Question 6

What are self correcting anomalies in mixed dentition?

Answer 6

• Anterior deep bite
• Md anterior crowding
• Ugly duckling stage
• End on relationship

Question 7

Why is anterior deep bite present in primary dentition?

Answer 7

• Incisors are more upright (more vertical inclination- interincisal angle around 150°)
• Infra-occlusion of partially erupted molars

Question 8

EXAM NOTE

Answer 8

pic may be given and we could be asked what tx is required → may just be observation

Question 9

When do you correct anterior deep bite?

Answer 9

Wait until both upper and lower incisors have erupted completely. Approx 10 years.

Question 10

Why is midline diastema present in ugly duckling stage?

Answer 10

Permanent canine force exerts pressure on lateral incisor which then exerts pressure on central, leading to midline diastema

Question 11

9-10 year old- large front teeth, midline diastema. How to treat?

Answer 11

Ugly duckling stage. No need for ortho treatment. Condition will correct by itself.

Question 12

3 types of spacing

Answer 12

• Physiologic (generalised spacing- less likely to get crowding)
• Leeway (contributes to future class I molar relationship in permanent dentition)
• Primate

Question 13

Can retrognathic md during pre dental period be used as a reliable diagnostic criteria for predicting subsequent arch relationship?

Answer 13

No. But if A-P dimension of gum pads is greater, the possibility of child developing malocclusion is greater

Question 14

What does anterior open bite and retrognathic md help with in pre dentate children?

Answer 14

Helps in suckling

Question 15

How does anterior open bite in pre-dental child present?

Answer 15

Upper and lower gums pads are approximated

• Contacts only at molar region
• Space exist in anterior region

Question 16

How is anterior open bite in pre dental child self corrected?

Answer 16

At 6-7 months by eruption of primary incisors

Question 17

What is infantile swallowing?

Answer 17

Different from mature swallowing

1. Nipple drawn into mouth
2. Tongue protrudes between nipple and lower lip
3. Milk is directed to pharynx
4. Milk passes between faucial pillars and lateral channels of pharynx
5. Excess milk dribbles down chin

Question 18

What are features of infantile swallowing outlined by moyer?

Answer 18

• Jaws are apart- tongue placed between upper and lower gum pads
• Md stabilization by contraction of muscles of facial nerve and interposed tongue
• Swallow is guided and controlled

Question 19

How is infantile swallowing self corrected?

Answer 19

• Gradually disappears with eruption of teeth and as infant beings to eat solid food (approx 1st year)
• When tongue is contained within dental arch, it indicates onset mature swallowing

Question 20

Why does tongue go between anterior region of gum pads during infantile swallowing?

Answer 20

To swallow, anterior open bite needs to be closed. This is achieved by placing tongue between gum pads during swallowing

Question 21

What is adults vs primary interincisal angle?

Answer 21

• Adult: 123°
• Primary: 150°

Question 22

What is anterior deep bite in primary dentition corrected by?

Answer 22

• Complete eruption of primary molars (inc VDO)
• Attrition of incisal edges
• Forward and downward growth of md

Question 23

What are physiological spaces in primary dentition mx and md?

Answer 23

• Mx: 4mm
• Md: 3mm

Question 24

What do spaces indicate and what are they good for?

Answer 24

• Spaces are important for normal development
• Spaces can be used for adjustment of permanent successors which are always larger
• Absence of spaces indicates crowding may occur in permanent dentition

Question 25

How are spaces in primary dentition self corrected?

Answer 25

* Eruption of larger permanent successors * Eruption of 1st permanent molar (early mesial shift)

Question 26

What are the 3 primary molar relationships?

Answer 26

A. Flush terminal plane B. Distal step terminal plane C. Mesial step terminal plane

Question 27

How are primary molar relationships self corrected?

Answer 27

Mesial eruptive force of first permanent molar * Early mesial shift: using primate spaces * Late mesial shift: using leeway spaces

Question 28

How do the 3 different primary terminal planes predict permanent molar relationship?

Answer 28

* Flush terminal plane → class I (56%), class II (44%) * Mesial step → If \<2mm, class I likely. If \>2mm, class III likely * Distal step → class II likely

Question 29

How does edge to edge bite happen in primary dentition?

Answer 29

By downward growth of md, over jet decreased gradually

Question 30

How is edge to edge bite in primary dentition self corrected?

Answer 30

* Eruption of permanent incisors * Having more labial inclination (interincisal inclination 123°)

Question 31

Why is anterior deep bite present in mixed dentition (6-12/13yrs)

Answer 31

Due to large permanent successor incisors

Question 32

How is anterior deep bite self corrected in mixed dentition?

Answer 32

Complete eruption of primary molars increase vertical dimension

Question 33

Why is mandibular anterior crowding present in mixed dentition?

Answer 33

* Disproportion between tooth size and arch length * Caused by exchange of larger permanent md incisors in narrow lower arch

Question 34

How is md anterior crowding self corrected in mixed dentition?

Answer 34

* Increased intercanine width by jaw expansion * Tongue pressure can cause forward migration of lower incisors

Question 35

How does minor vs moderate crowding resolve?

Answer 35

* Minor: resolves spontaneously by development * Moderate: use of leeway space (preventing mesial movement of permanent molar)

Question 36

What is ugly duckling stage?

Answer 36

* Seen at 8-11 years of age and indicates unaesthetic appearance of child * Centrals appear huge (let them know it is relative appearance) * Difference in dimension of primary and permanent teeth (permanent centrals and laterals, primary canines and molars)

Question 37

How is ugly duckling stage self corrected?

Answer 37

Complete eruption of permanent maxillary canine

Question 38

What is end on end relationship in mixed dentition?

Answer 38

* B cusp tip of permanent mx 1st molar coincide with B cusp of permanent md 1st molar. * Obtained in mixed dentition period following flush terminal relation in deciduous dentition

Question 39

What is end on end relationship in mixed dentition self corrected by?

Answer 39

* Eruptive force in M direction of permanent md molars * Late mesial shift in non-spaced dentition

Question 40

What is the likely permanent relationship that will come from end to end relationship in mixed dentition?

Answer 40

* 75% shift toward class I relationship * 25% shift into class II relationship

Question 41

What are self correcting anomalies in permanent dentition?

Answer 41

Increased overjet and overbite