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Crowding in mixed dentition. By: Dr. Richa Khanna. introduction. Crowding in mixed dentition is a common finding especially in mandibular anterior region The most important reason for lower incisor crowding in mixed dentition is ‘ Incisal liability’.
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Crowding in mixed dentition By: Dr. RichaKhanna
introduction Crowding in mixed dentition is a common finding especially in mandibular anterior region The most important reason for lower incisor crowding in mixed dentition is ‘Incisal liability’
Factors that help to resolve this crowding: • INTERDENTAL SPACING • Help in lateral shift of deciduous canines when permanent incisors erupt • If spacing is absent this shift is not possible, and cances of self-alignment decrease
2. INTERCANINE ARCH WIDTH • Increase in intercanine width help yo resolve this crowding • The increase is about 6mm in maxilla and 4mm in mandible. 3. INCLINATION OF PERMANENT INCISORS- also help to relieve crowding 4. Ratio of size of permanent and primary teeth.
Management • OBSERVATION – for space requirement less than 2 mm. • DISKING OF PRIMARY TEETH – for space requirement between 3-4 mm - Can be done by strips or fine burs - Teeth may correct spontaneously or may need lingual arch with auxillary springs
3. EXTRACTION OF PRIMARY TEETH • Extractions are needed when space requirements are ecxessive. • The most common procedure in this context is SERIAL EXTRACTIONS
SERIAL EXTRACTIONS - coined by Kjellgren • Popularised by Nance: known as ‘Father of serial extraction’ • Also known as ‘GUIDANCE OF ERUPTION’ DEFINED AS: Correctly timed, planned removal of certain deciduous and permanent teeth in mixed dentition stages with dentoalveolar disproportion.
Indications: • Class I with anterior crowding(space disc. > 10mm) • Lingual eruption of lateral incisors • Midline shift potential due to unilateral canine loss • Crowded arches with extreme proclination • Abnormal primary canine root resorption • Lack of developmental spacing • Anamolies such as ankylosis, ectopic eruption
Contraindications: • Mid to moderate crowding • Congenital absence of teeth • When removal of first permanent molars due to caries is needed • Accompanying deep or open bites without correction • Severe class II/III of dental or skeletal origin • Cleft lip/palate cases
INVESTIGATIONS/EXAMINATION NEEDED • Clinical examination • Study models • X rays • M-d analysis • Photographs- facial
procedure • Dewel: CD4 • Tweed : D4C • Nance: CD4
Disadvantages: • May need follow up fixed appliance therapy • Patient compliance is a factor • Not an option in case of impacted permanent canines.