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Interceptive Orthodontics

Professor Dr. Sun Sun WinProfessor & Head

Children’s Dentistry & Orthodontics Department University of Dental Medicine,Yangon



Interceptive Orthodontics

• Certain malocclusion need correction at an earlier stage

in order to facilitate normal development of the

occlusion or to reduce the severity of malocclusion.

• This kind of early intervention is called interceptive

orthodontics.

( Not all malocclusions can be prevented )



Common malocclusions which need early intervention are

1. Early loss of primary teeth.

2. Retained primary teeth.

3. Anterior cross-bite (with displacement).4. Posterior cross-bite with displacement

5. Median Diastema

6. Harmful Para-functional habits

7. Supernumerary teeth



1. Early loss of primary teeth.

Unilateral loss centreline shift.

- Delayed eruption of permanent tooth.

- Centre line shift.

- Localised crowding.

- Including loss of space due to inter - proximal caries



Management

To prevent early loss of primary teeth.

• Use of fissure sealants.

• Restore carious teeth.

• Dietary advice.

• Use of fluoride



2. Retained Primary teeth

- cross-bite

- median diastema

- displacement of the permanent teeth.

- rotation

Treatment remove the retained primary teeth.



3. Anterior Crossbite

One or more upper incisors occlude lingual to the

corresponding lower incisors.

Causes

Class III skeletal pattern

Crowding

Retained primary teeth

Presence of supernumerary teeth.

Trauma.



Management

- Remove etiological factors.

- Differentiate skeletal problems from others.

(a) Tongue blade correction.

(b) Lower inclined bite plane.

(c) Removable appliance with either cantilever spring or

screw.



(a) Tongue blade correction.

- tongue blade correction. ( e.g.: anterior cross-bite 1 )

- maxillary incisor is still erupting, with no major overtbite

and adequate space for 1



The patient is instructed to insert the tongue blade at an

angle between the teeth and bite firmly, maintaining

the pressure for 5 sec, then interrupt and repeat for 25

times.



• 3 times a day.

• if the tongue blade exercise is not

successful after 2 wks (or)

• if tooth eruption is too advanced, a bite

plane is more satisfactory.



(b). Lower inclined bite plane.

• have sufficient inclination to produce a definite

forward sliding

• motion of the maxillary incisor on closure.

• should not impinge on soft tissue of the

mandibular teeth.



- the appliance is cemented with a temporary cement.

- the posterior teeth will be slightly out of occlusion.

- is used for no longer than two weeks.



(C) Removable appliance with either cantilever

spring or screw

• single tooth – single or double cantilever spring.

• of more teeth are in cross bite – crossed

cantilever or a screw.



• E.g. : instructions to the technician on applianceconstruction.

• Appliance design for a case with incisor cross-bite

on a child in a mixed dentition.

• Adam’s clasps on6 6

+D D

orE E

• Double cantilever spring ( Z spring) on 1

• Posterior bite plane half molar capping withadequate thickness.





4. Posterior crossbite with displacement

- A unilateral posterior crossbite with displacement is

easily corrected during the mixed dentition,

- But one without an associated displacement is

probably skeletal in origin and correction should

not be attempted.



Possible causes

• Narrow maxilla

• Deviated path of eruption of maxillary first

permanent molar.

Clinical features

• Cross-bite involving one or more posterior teeth

• Lateral displacement of the mandible.



Design of the appliance

- Adams Clasps on 6D / D6

- Mid line expansion screw

- Half molar capping sufficiently thick to relieve

occlusal interference.



5. Median Diastema

Median Diastema spacing between

1 1

Common Causes

a. Physiological diastema

b. Retained primary teeth

c. Supernumerary teeth

d. Missing Lateral incisore. Fibrous frenum

f. microdontia 2 2





(a). Physiological diastema

• The diastema which develops between two

permanent central incisor is transient abnormality.

• Permanent incisors erupt into a more forward and

proclined position than their predecessors.



- Normally this space closes spontaneously as the lateralincisors erupt, but may persist even after the lateral

incisors have erupted, particularly if the primary canines

have been lost and upper incisor become flared to the

labial.

( ugly duckling stage of development ).- No need of early correction and close spontaneously



(b). Retained primary teeth

• Remove the primary tooth and observe spontaneous

space closure.

• If the space is not closing, close the diastema using

an appliance.

(c). Supernumerary teeth

• Management of Supernumerary teeth



(d). Missing Lateral incisor

Space closure between 1 1

Replacement (prosthesis) for missing lateral incisor.

(e). Fibrous frenum

Due to high frenum attachment ( Presence of

fibrous frenum extending from the incisive papilla to the

inner surface of the upper lip



(X-ray – inverted V shaped notch between central incisor

where the fibrous tissue of the frenum is attached.

Frenectomy after eruption of 3 3 and space

closure,

(f). Microdontia

Peg shaped lateral incisor 2 2

Space closure, crown build-up of 2 2 up to

normal form and size.



Choice of the appliance

• Choice of the appliance depend on the width of the

diastema and the inclination of the incisor teeth.

• If the space is less than 2 mm or teeth are distally inclined

simple tipping movement with a removable

appliance can move the teeth into a normal

alignment.



6. Harmful Parafunctional habits

(a). Thumb sucking

(b). Finger sucking

(c). Nail biting

(d). Dummy sucking

(e) Lip sucking

(f). Prolonged bottle feeding

(g). Tongue thrust and mouth breathing habits



- The presence of an oral habit in the 3 to 6 year old

child is an important finding during clinical

examination.

- 6 year - is not usually present> 6 year – effect on eruption of permanent teeth

and occlusion.

Thus – should be eliminated before the permanent

incisors erupt.



Thumb and Finger Habits

-Highly specified cause – and – effect relationship.-Types of dental changes vary with intensity,

duration and frequency of the habit as well as the

manner in which position of the digit in the mouth.

- 4 to 6 hrs of force per day are probably the minimum

necessary to cause the movement.-A child who sucks continuously ( > 6 hrs ) can

cause significant dental changes.



Features of malocclusion

1. proclination of upper incisor2.retroclination of lower incisor

3.retardation of eruption of upper and lower teeth

4.asymmetric anterior open bite depending on the

side where the finger is held

5. adaptive tongue thrust

6. maxillary constriction – posterior cross bite.



Management

-Persuade the child to stop the habit

-Identify the child who is willing to stop the habit but

unable to do so at night

-Fit habit breaking appliance

-Correct adaptive tongue thrust using a tongue guard.





Dummy sucking ( Pacifier Habits )

-similar to changes created by thumb habits

-but ended before 5 years of age

-easy to stop this habits

-then start sucking a digit

-elimination of the subsequent finger habit maybecome necessary



Lip Habits ( Lip sucking )

-most lip habits do not cause

dental problems

-can maintain an existing malocclusion

-result is

a proclination of the maxillary incisorsa retroclination of the mandibular incisors

an increased overjet



• Nail Biting

-no evidence it can cause malocclusion

or dental change

-other than minor enamel fracture

-some reported incisor rotation



Tongue Thrust and Mouth Breathing Habits

-tongue thrust is characteristic of the infantile

swallowing

-no simple cause – and – effect relationship

-may be able to sustain and open bite but not create one

( Proffit and Mason, 1975 )

-should be considered a finding and not a problem to be

treated



Mouth Breathers

-because of mandibular posture or incompetent lips or

a suspected nasal airway obstruction

-a weak relationship between mouth breathing and

malocclusion characterized by a long lower face and

maxillary constriction



End