Vertical Discrepancies

Question 1

what is the definition of an overbite

Answer 1

vertical overlap of the incisors

Question 2

what is WNL of overbite

Answer 2

0-4mm

Question 3

what is ideal overbite

Answer 3

1-2mm

Question 4

what is overbite important for

Answer 4

masticatory incision and anterior guidance

Question 5

what percentage of the population has an extremely open overbite and what is the measurement

Answer 5

greater than -4mm
- 0.1%

Question 6

what percentage of the population has a severely open overbite and what is the measurement

Answer 6

-3 to -4mm
0.5%

Question 7

what percentage of the population has a moderateley open overbite and what is the measurement

Answer 7

• 0 to -2mm
• 2.7%

Question 8

what percentage of the population has an ideal overbite and what is the measurement

Answer 8

0 -2mm
- 47.5%

Question 9

what percentage of the population has a moderately deep overbite and what is the measurement

Answer 9

3-4mm
-33.1%

Question 10

what percentage of the population has a severely deep overbite and what is the measurement

Answer 10

• 5-7mm
  14.2%

Question 11

what percentage of the population has an extremely deep overbite and what is the measurement

Answer 11

greater than 7
1.7%

Question 12

what is the most common cause of a dental open bite

Answer 12

digit habit/tongue thrust

Question 13

what is the treatment for dental open bite in primary/mixed dentition

Answer 13

usually self corrects once habit is corrected

Question 14

what are the features of open bite in permanent dentition

Answer 14

• max incisors flared
• narrow, high palate and mandibular incisors tipped lingually with digit habit
• mandibular incisors flared labially with tongue thrust

Question 15

what is the prevalance of posterior/lateral open bite

Answer 15

rare

Question 16

what can a posterior/lateral open bite be due to

Answer 16

• tongue habit
• crowding
• ankylosis (usually primary second molars)
• primary failure of eruption

Question 17

what is the dx and tx for primary failure of eruption in posteiror/lateral open bite

Answer 17

• difficult to diagnose- diagnosis of exclusion
• no good treatment option
• ortho treatment makes it worse

Question 18

what is the role of the dentist in the management of open bites

Answer 18

• early dx/referall to orthodontist
• determine if it is skeletal or dental issue
• encourage the patient to stop the habit ASA: habit appliances
• educate the patient and parent of long term ramificiations/tx options: surgery/trauma/extractions/comprehensive ortho. open bite will worsen with time

Question 19

describe deep bites

Answer 19

• excessive overlap of the anterior teeth- greater than 2mm
• can be skeletal or dental
• may worsen with time
• incisor wear is common
• palatal tissue may be impinged on
• class II molar classification common

Question 20

why treat deep bites

Answer 20

• prevent trauma
• facilitates restorative dental treatment
• esthetics

Question 21

what trauma can occur with deep bites

Answer 21

• lower incisor attrition: can happen at an early age like teens
• palatal tissue (impinging bite =100%)

Question 22

what esthetic issue can be avoided in deep bites

Answer 22

extrusion of upper incisors may cause gummy smile

Question 23

the dentist should dx early and refer to ortho especially with:

Answer 23

early loss of primary teeth or severe class II