crossbite/transverse problems

Question 1

Anterior Crossbite
* Prevalence:
* Manifested in?

Answer 1

• Prevalence: 2.2% to 11.9%
• Manifested in the mixed dentition

Question 2

what arises with no tx of crossbites
* Esthetics?
* Damage to the teeth?
* Gingiva?
* alveolar bone loss?
* mobiility?

Answer 2

• Esthetic problem
• Damage to the teeth in crossbite through attrition
• Gingival recession
• Loss of alveolar bone on lower incisors
• Excess mobility of lower incisors affected by the crossbite

Question 3

what occ classes can crossbites be?

Answer 3

any of the three

Question 4

how can we differentiate crossbite etiologies

Answer 4

cephalometrics
dental assesment
functional assesment
profile analysis

Question 5

SNA and SNB angles

Answer 5

SNA: indicates max relation in sag plane
SNB: indicates man relation in sag plane

Question 6

ANB measurement

Answer 6

if + maxilla is protruded, if - mandible is protrouded (ant cross bite)

Question 7

dental assessment of crossbite

Answer 7

• Class III molar relationship
• (-) overjet or end-to-end relationship with retroclined mandibular incisors (compensated class III malocclusion)
• If negative overjet, proceed to functional assessment

Question 8

functional assessment

Answer 8

Determine whether a centric relation/centric occlusion (CR/CO) discrepancy exists

Question 9

what if a pt presents with severe ant crossbite and there is a shift in CR creating end to end?

Answer 9

indicates the max I are retroclined(psedpclass 3)

Question 10

Functional assessment
* At CR, pt may have?
* At CO, patient may have?

Answer 10

• At CR, patient may have a Class I skeletal pattern, normal facial profile and Class I molar relationship
• At CO, patient may have a Class III skeletal and dental pattern

Question 11

DENTAL ASSESSMENT
(Molar relationship & overjet) flow chart

Answer 11

Question 12

skeletal vs dental ant crossbite ceph results

Answer 12

Question 13

skeletal vs dental ant crossbite dental results

Answer 13

skeletal:
* Severe proclination of upper incisors
* Severe retroclination of lower incisors
* Class III molar relationship MAY or MAY NOT be present in Class III skeletal

Dental:
* Normal inclination/position or severe retroclination/retrusion of upper incisors
* Severe proclination/protrusion of lower incisors
* Class I or II molar relationship
* Presence of anterior functional shift MAY or MAY NOT be present in Class III dental*

Question 14

skeletal vs dental ant crossbite profiles

Answer 14

Skeletal: concave or striaght, may not be present in class3
dental: straight/convex

Question 15

Early Treatment of dental
anterior crossbite

• The most common etiologic factor?
• Focus the treatment plan on?
• Management options:
• Extractions?
• Disking?
• Opening space?
• Determine whether?

Answer 15

• The most common etiologic factor for nonskeletal anterior crossbites is lack of space for the permanent incisors
• Focus the treatment plan on management of the total space situation, not just the crossbite
• Management
• Extraction of adjacent primary teeth to provide necessary space
• Disking of teeth
• Opening space for tooth movement
• Determine whether tipping will provide appropriate correction

Question 16

Early Treatment of dental anterior crossbite fixed appliances

Answer 16

• Fixed inclined planes
• Reverse crown: A large permanent anterior tooth crown is reverse-cemented to create a gliding plane for max anteriors
• Maxillary lingual holding arch with springs: Lingual eruption of maxillary lateral incisors in a crowded arch

Question 17

what removable applaince could be used for ant crossbites

Answer 17

removable with jackscrew to engage teeth

Question 18

2x4 appliance

Answer 18

used to correct ant crossbites: 2 molars with brackets and all four anteriors with brackets for tipping

Question 19

referal for earlt tx of ant crossbites

Answer 19

• Must refer to orthodontist
• Objective is to reduce the amount of dental compensation to skeletal;
  discrepancy that are often associated with a more severe malocclusion in
  late adolescence

Question 20

facemask use for ant crossbites

Answer 20

use of elastics and facemask to protrude maxilla for early ant crossbite tx

Question 21

posterior crossbite prevalence

of Hispanic population
in African-American population
among Caucasians

Answer 21

• 7.3% of Hispanic population
• 9.6% in African-American population
• 9.1% among Caucasians

Question 22

most common cause of post crossbite

Answer 22

Transverse maxillary deficiency: narrow
maxilla relative to the rest of the face

Question 23

posterior crossbites of dental cause?

Answer 23

possible to have normal palatal width but with L inclined posterior maxillary teeth

Question 24

Hidden Posterior Crossbite
* Compensatory changes in dentoalveolar process

Answer 24

• Tipping of maxillary teeth to the buccal
• Tipping of mandibular teeth to the lingual
• Uprighting teeth creates a dental crosbite

Question 25

Unilateral Posterior Crossbite * May be a? * Key sign:

Answer 25

* May be a bilateral crossbite with a functional lateral jaw shift as the teeth from centric relation to centric occlusion * Key sign: deviation of the mandibular dental midline, relative to the maxillary dental and skeletal midlines, toward the side of the crossbite when the teeth are in maximum intercuspation

Question 26

posterior crossbites due to functional shift sequelae: 1. Compensatory changes where? 2. Modifications of? 3. Development of? 4. teeth?

Answer 26

1. Compensatory changes in the TMJ? 2. Modifications of soft tissue growth? 3. Development of skeletal asymmetries? NO STRONG EVIDENCE 4. Attrition of teeth

Question 27

Do Posterior Crossbites due to functional shifts have self correction?

Answer 27

do not self correct, must be tx

Question 28

Posterior Crossbites management * skeletal or dental? * sides? * shift? * If dental, which teeth are? * when should this be tx? * Should the problems be corrected? * Can the problem be corrected or masked by treatment?

Answer 28

* Is the crossbite skeletal or dental? * Is the crossbite unilateral or bilateral * Is there a functional shift? * If dental, which teeth are tipped and in which jaws? * Should the treatment be initiated at this time or deferred to a later date? * Should the problems be corrected? * Can the problem be corrected or masked by treatment?

Question 29

management of simple unilateral posterior crossbite

Answer 29

Fixed or removable appliances to move teeth * W-arch, quadhelix (up to age 9 or 10) * Jackscrew: relatively heavy force that separates the partially interlocked suture

Question 30

# types of palatal expansion anchorage and rates of expansion

Answer 30

Question 31

# early mixed dentition tx of post crossbite, rate of tx?

Answer 31

use slow expansion

Question 32

# suture expansion ages/how to assess

Answer 32

* Suture can be separated in females up to age 16, and in males up to age 18 * An occlusal radiograph is used to assess the midpalatal suture patency

Question 33

Buccal Crossbites (scissor bite) * tooth positions * A complete buccal crossbite (Brodie bite)?

Answer 33

* Buccal displacement of a maxillary posterior tooth, with or without contact between the lingual surface of the maxillary lingual cusp and the buccal surface of the mandibular antagonist's buccal cusp. * A complete buccal crossbite (Brodie bite): a combination of excessive maxillary width and a narrow mandibular alveolar process, although the width of the mandibular base is usually normal

Question 34

Scissor bite tx options

Answer 34

**most difficult to tx * Elastics * Mandibular appliance to upright posterior teeth * Lip bumper