interceptive orthodontics

INTERCEPTIVE ORTHODONTICS


• Definitions:

Any procedure that eliminates or reduces the severity of malocclusion in the developing dentition.(Popovich and Thompson 1979, Hiles 1985.)

All simple measures that eliminate the developing mal occlusion. (Ackerman and Proffit 1980)


The aetiology of malocclusion could be:

1- Skeletal discrepancy

2- Soft tissue

3- local factors

4- Crowding and spacing

5- Displacements


Local factors: DELAYED ERUPTION OF UPPER PERMANENT CENTRAL INCISOR.• Definition: 1 is considered to be delayed if the

contra-lateral tooth was fully erupted or if teeth later in the usual eruption sequence were present.

• Interceptive treatment: removal of supernumerary with or without tooth exposure.

• Treatment timing: as soon as the supernumerary tooth is detected.


Local factors:RETAINED DECIDUOUS

TEETH.

• Definition: the deciduous tooth is considered to be over retained if it made enamel contact with its successor.

• Interceptive treatment: extraction.


Local factors: INFRAOCCLUSION• Definition: the tooth loses its vertical position

relative to the adjacent teeth and assumes a position below the occlusal plane

• Frequent site: lower 2nd and 1st primary molars.• Interceptive treatment: nothing unless the

permanent successor was absent or the infraoccluded tooth is likely to disappear .


Local factors: UNILATERAL RETAINED DECIDUOUS CANINE.• Definition: premature loss of one deciduous

canine as a result of early root resorption by a crowded lateral incisor.

• Interceptive treatment: extraction of the primary canine on the opposite side of the arch to preserve the midline.


Local factors: DOUBLE TEETH

• Definitions:

Gemination: the attempt of a single tooth bud to form two distinct morphological entities.

Fusion: the result of joining two adjacent tooth buds.


Local factors: DOUBLE TEETH• In the deciduous dentition double teeth are usually

associated with absent permanent successor, or ectopic or delayed eruption of the permanent successor if it was present. Treatment therefore involve the extraction of the malformed tooth.

• In the permanent dentition treatment options are: Mask, Split and Extract


Local factors: ECTOPIC ERUPTION OF THE PERMANENT FIRST MOLAR.

• Definition: the molar erupts at an angle mesial to its normal path of eruption.

• Types : reversible and irreversible

• Treatment: extraction of E or distalisation of permanent molar


Local factors: Hypodontia

• Definition: Absent teeth.

• Common teeth: lower 2nd premolar & upper lateral incisor.

• Treatment: space closure or space maintenance for future prosthesis.


Local factors:DIASTEMA

• Definition: space between the two upper central incisors.

• Treatment if indicated: removal of pathology (supernumerary, odontome, fraenum?….)


Local factors: ECTOPIC UPPER CANINE

• Definition: the canine erupts out of its normal eruption path.

• Diagnosis: If the 3 was not palpable in the buccal sulcus after the age of 10 years.

• Treatment: Extraction of the deciduous canine.


Local factors:ECTOPIC UPPPER CANINERate of eruption of the permanent canine after

the extraction of the deciduous canine depends on the amount by which the permanent canine overlap the lateral incisor:

overlap < 1\2 of lateral root: success rate 91% overlap > 1\2 of lateral root: success rate 64% (Ericson & Kurol 1988)


Local factors: THUMB SUCKING

• Effect: no malocclusion 14.6%

anterior open bite 48.1%

posterior cross bite 07.2%

ant OB +post X-bite 30.1%

(Da Silva et al. 1991)


Local factors: THUMB SUCKING• At what age should treatment be started?-Da Silva et al (1991)“from the 5th year of age”-Proffit (1993) “before the eruption of permanent incisors”-Houston (1993) “ by 7-8 years of age “-Mills (1982) “before permanent dentition”-Larsson (1987) “before pubertal growth spurt”


Local factors: THUMB SUCKING

• Treatment:

1- Adult approach.

2- Deterrent appliance.


Local factors: TRANSPOSITION• Definition: unusual type of ectopic eruption were

two permanent teeth have interchanged their location in the dental arch.

• Frequent sites: upper canine and first premolar lower canine and lateral incisor.• Interceptive treatment: extract transposed tooth. align before canine eruption• Treatment timing: before eruption of canine.


Crowding:• Treatment:1-Space management.2-Molar distalisation.3-Serial extraction.4-Premolar extraction.5-First molar extraction.6-lower incisor extraction.7-Second molar extraction.


Crowding: SPACE MANAGEMENT.

• Definition: utilization of Lee Way space to relieve anterior crowding.

• Indications:1- Cl I molar relation ship.

2- E,s are still present in the.

crowded side(s).

3- Mild crowding.


Crowding:SPACE MANAGEMENT• Methods:1-Space maintainer extract E,s

Or

2- Slice the mesial surface of the

deciduous canine and molars

before the eruption of permanent

canine and premolars.


Crowding:SERIAL EXTRACTION

• Definition: ”.. The early recognition or anticipation of a deformity that will occur unless teeth are removed at a strategic interval to relieve in intensity the developing malocclusion.”


Crowding:SERIAL EXTRACTION• Indications: - The incisors are substantially crowded.- Age 8-9 years.- Normal arch relation ship.- Reduced or normal overbite.- All permanent teeth are present.- The first molars should have a good prognosis.- The first premolars should be closer to eruption than

canines.


Crowding:SERIAL EXTRACTION

• Disadvantages:

1- Increasing the overbite.

2- Lingual tipping of lower incisors

3-Retarding future development in arches.

4-Lack of aesthetic fullness of the lips.

5-Rotated incisors do not align spontaneously.


Crowding:SERIAL EXTRACTION• Methods:1-When the lateral are erupting in a crowded

position, all deciduous canines are removed.2-When the roots of the first deciduous

molars are half resorbed. They are removed.3-As soon as the first premolars erupt they are

removed.

FIRST MOLAR EXTRACTION

As an interceptive orthodontic measure


• Indications:-At least one permanent first molar have poor

prognosis.-Crowding in the relevant quadrant.-The development of second molar roots did not

reach more than half way.-No other missing teeth in the same quadrant.-Normal arch relation ship.-The overbite is not deep.-The second premolar is contained within the E roots


• Advantages:– No need for future prosthesis– Reduce incisor crowding– Eliminate buccal segment crowding– Less chance for third molar impaction.


• Disadvantages:– The uncertainty of the final contact point

between the second molar and second premolar.


0

20

40

60

80

100

Thunold Thilander

good

poor

• Contact point:• Good result could be

expected in patients:– Having buccal segment

crowding.

– having third molars.

– First molars were extracted early.


• Compensatory extraction:

– Extraction of upper first molar does not necessitate the compensatory extraction of lower first molar

– Extraction of lower first molar necessitates the compensatory extraction of upper first molar

interceptive orthodontics

Health & Medicine

interceptive treatment

permanent canine

eruption of canine

permanent teeth

irreversible treatment

deciduous tooth

deciduous teeth

primary canine