In the name of GOD

Treatment of occlusal relationship problems

in preadolescent children

Presented by:

Dr Somayeh Heidari

Orthodontist

Reference:

Contemporary Orthodontics

Chapter 12

William R. Proffit, Henry W. Fields, David M.Sarver. 2007. Mosby

Special considerations in early treatment

The goals of treatment must be clearly outlined and understood

Problems of too long treatment:

patient can be “burned out”

the chance of damage to the teeth

Fewer options are available, and patient cooperation is more critical

There are important biomechanical differences between complete and partial

appliances

Typical fixed appliance for mixed dentition treatment:

2 × 4

2 × 6

( 2 molar bands, 4 or 6 bonded anterior teeth)

2 × 4 or 2 × 6 :

longer archwire span

more springy and less strong wire

light forces ( easier intrusion of teeth)

appropriate moments

more prone to breakage, distortion and displacement

Anchorage control is both more difficult and more critical

Extraoral support ( Headgear or Facemask) and maxillary and mandibular

lingual arches can be used

Implant supported anchorage usually is not practical:

unerupted teeth

reduced density of the bone

Beware of unerupted teeth

Space closure must be managed with particular care

Teeth without attachments may tend to be displaced and squeezed out of the arch

Interarch mechanics must be used sparingly if at all

Interarch forces are not recommended under must circumstances with

one exception: Cross elastics (in treatment of unilateral cross bite)

Final results are dictated largely by the untreated arch

Retention often is needed between mixed dentition treatment and eruption

of the permanent teeth

wires can interfere with eruption of permanent teeth

need to patient cooperation

increase the chance of patient burn-out

Occlusal relationship problems

Crossbite

Crossbites of dental origin

usually affect only some of the teeth

less sever than skeletal crossbites

occlusal interferences often are present (increased chance of shift on closure)

Treatment in the mixed dentition is recommended because:

Eliminates functional shift

wear of erupted permanent teeth

possibly dentoalveolar asymmetry

Increase arch circumference

Relapse is unlikely in the absence of a skeletal problem

Simplifies future treatment

Posterior Crossbite

treatment differs depending on its underlying cause

dental crossbites are treated by moving the teeth with light forces

heavy force and rapid expansion are not indicated in the primary or early

mixed dentition significant risk of nose distortion

Basic approaches to the treatment of moderate posterior crossbite in children:

equilibration to eliminate mandibular shift

expansion of a constricted maxillary arch

repositioning of individual teeth to deal with intra-arch asymmetries

A shift into posterior crossbite:

in a few cases

in primary or early mixed dentition

due solely to interference caused by the primary canines

diagnosed by careful positioning of the mandible

require only limited equilibration of the primary canines

A greater maxillary constriction:

allow the maxillary teeth to fit inside the mandibular teeth without shift on closure

reduced arch circumference

crossbite correction will provide more space

small constriction creates dental interferences that force the mandible to shift

Whether or not a mandibular shift is present, a crossbite due to a narrow

maxilla should be corrected when it is noted, in the primary or mixed dentition,

unless the permanent first molars are expected to erupt in less than 6 months.

It is possible to treat posterior crossbite with a split-plate type of removable

appliance, there are two problems:

this relies on patient compliance for success

the appliance can be displaced easily

The preferred appliance for modest expansion of the maxillary arch in a

preadolescent child is an adjustable lingual arch.

Both the W-arch and the quad helix are reliable and easy to use.

W-arch

fixed appliance

constructed of 36 mil steel wire soldered to molar bands

activated simply by opening the apices of the W

easily adjusted to provide more anterior than posterior expansion, or vice

versa

delivers proper force when opened 4-5 mm wider than passive width

should be adjusted before being inserted

it is not uncommon for the teeth and maxilla to move more on one side

Quad helix

more flexible version of W-arch

the bulk of the anterior helices can effectively serve as a reminder to stop habit

combination of a posterior crossbite and a sucking habit is the best indication

greater range of action than the W-arch but the forces are equivalent

Both appliances:

leave an imprint on the tongue, that will disappear when the appliance is removed

some opening of the midpalatal suture can be expected in a young child

expansion should continue at the rate of 2 mm per month ( 1 mm on each side)

until the crossbite is slightly overcorrected

intraoral appliance adjustment may lead to unexpected changes

require 2 to 3 months active treatment and 3 months of retention

True unilateral crossbite:

ideal treatment is to move selected teeth on the constricted side

to a limited extent, this can be achieved by using different length arms, but some

bilateral expansion must be expected

an alternative is to use a mandibular lingual arch to stabilize the lower teeth

and attach cross-elastics to the maxillary teeth

this is more complicated and requires cooperation, but is more unilateral in its

effect

a third alternative is to use a removable appliance that sectioned asymmetrically

this appliance has the same restrictions as all removable appliances

If teeth in both arches contributed to the problem:

Cross-elastics between banded or bonded attachments in both arches

the force has a vertical vector which will extrude the posterior teeth and

reduce the overbite caution in child with increased lower face height

or limited overbite

crossbite should be overcorrected, and attachments left in place immediately

after active treatment

when the occlusion is stable after several weeks without elastic force, the

attachments can be removed.

the most common problem is lack of cooperation from the child.

Anterior Crossbites

most children with anterior crossbite, especially if more than one or two teeth

are in crossbite, have a skeletal problem

the most common etiologic factor for nonskeletal

anterior crossbite is lack of space for the permanent incisors

if the developing crossbite is discovered before eruption is complete and

overbite has not been established, the adjacent primary teeth can be extracted

to provide the necessary space.

only occasionally the anterior crossbite treatment is indicated in the primary

dentition

dental anterior crossbites typically develop as the permanent incisors erupt

those diagnosed after overbite is established require appliance therapy

the first concern is adequate space bilateral disking

extraction of the adjacent primary teeth

opening space

if teeth are tipped when bodily movement is required, stability of the result is

questionable.

in a young child, the best method for tipping anterior teeth out of crossbite is a

removable appliance

finger springs for facial movement of maxillary incisors

one 22 mil double helical cantilever spring

multiple clasps for retention

labial bow is usually contraindicated

active labial bow for lingual movement of lower incisors (less frequently)

Biteplate to reduce the overbite:

usually is unnecessary in children unless the overbite is exceptionally deep

it would be needed only in a child with a clenching or grinding habit

using a biteplate risks the chance that the teeth not in contact with the

appliance or opposing arch will erupt excessively

Removable appliance without biteplate

2 months

Teeth in the opposite arch are moving in the same direction

Biteplate is indicated and can be added to the appliance

This removable appliance :

requires nearly full time wear

if the springs are activated 1.5 to 2 mm, the teeth will move 1 mm in a month

the offending teeth should be slightly overcorrected

the teeth should retained until overbite is adequate to retention

one or two months of retention with a passive appliance

The most common problems:

lack of patient cooperation

poor design leading to lack of retention

improper activation

The simplest fixed appliance for correction of anterior crossbite:

a maxillary lingual arch with finger spring ( whip spring )

indicated for a child with compliance problems

the springs usually are soldered on the opposite side of the arch

it will increase their length

most effective if the length is approximately 15 mm

3 mm activation , will produce optimum rate of movement: 1 mm per month

the greatest problems are distortion, breakage and poor oral hygiene

2 × 4 appliance:

the best choice for an older patient with crowding, rotations and more permanent

teeth in crossbite in mixed dentition

forces and moments produced on the anterior teeth by a rectangular archwire

the torque and the coil springs tip the incisors facially

multiple incisors can be readily corrected in a short time

the roots of lateral incisors should not repositioned into the canine path of

eruption

Anterior Open Bite

Deep Bite

before treatment, it is necessary to establish its cause:

reduced lower face height

lack of eruption of posterior teeth

over eruption of the anterior teeth

Removable biteplate appliance:

for children who have less than normal eruption of the posterior teeth (usually

associated with reduced face height)

an anterior biteplate is incorporated into removable appliance

mandibular incisors occlude with the plastic plane, this prevent the posterior

teeth from occluding

treatment may take several months

appliance must be worn full time during active treatment

biteplate must continue to be worn at night as a retainer

If the maxillary or mandibular anterior teeth have erupted excessively:

more challenging approach

the task is to stop the eruption (relatively intrude) or actually intrude the incisors

this type of tooth movement requires light continuous forces and careful

management of the anchorage (posterior teeth)

intrusion as a part of early treatment is seldom indicated

Thanks for your attention