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Crowding and Spacing. Lecture 7 Ingrid Reed DDS, MS Department of Orthodontics & Dentofacial Orthopedics. Spacing. Primary Generalized – a good thing Primate spaces Maxillary –mesial of canine Mandibular – distal of canine Mixed dentition Permanent dentition. Primary Dentition.
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Crowding and Spacing Lecture 7 Ingrid Reed DDS, MS Department of Orthodontics & Dentofacial Orthopedics
Spacing • Primary • Generalized – a good thing • Primate spaces • Maxillary –mesial of canine • Mandibular – distal of canine • Mixed dentition • Permanent dentition
Causes of spacing • Normal developmental stage • Mesiodens • Tooth size to arch perimeter discrepancy • Missing teeth (especially maxillary lateral incisors) • Microdontia or peg laterals • Excessively protruded teeth • Large frenum • Habits- thumb sucking
Primary picsdigger.com
Mesiodens Primary Permanent 4.bp.blogspot.com dentistry4kids.net
Early mixed dentition • Normal eruption pattern of incisors is in a smooth arc • Erupting canines should close small spaces • 2 mm or less • > 2 mm or if not enough space for laterals may want to close with 2 x 4 • Must know what movements you are making since could cause resorption of the lateral roots against the unerupted canines
initial KW 6-15-05 Initial
Excessive anterior space >2 mm • Assess teeth present • Radiograph – check mesiodens, missing teeth • Occlusal radiograph – determine patency of the suture • Large frenum • Protruded incisors • Bolton tooth size discrepancy - small maxillary lateral and/or central incisors
6/11/09 age 11y 3 mo 2 years later
Treatment of generalized spacing Teeth are too small for arches • Increase tooth mass – crowns, implants • Decrease arch perimeter • Consolidate spaces • Tip teeth lingually • Distribute space distal to the canines
Crowding • Tooth – jaw size discrepancy • Too large a tooth mass to align in smooth arc in supporting bone • Protrusion of teeth must be included in analysis of crowding • Curve of Spee • Take into consideration using Leeway space to correct molar relationship
Age related crowding • Primary dentition • Rare to have crowding • Correction not proved to correct permanent crowding • Lack of space • Predictor of severe crowding of permanent dentition
Mixed dentition • Small amount (1-2 mm) of mandibular anterior crowding • Common because of incisor liability • Does Leeway space take care of it? • Look at radiographs – are 2nd premolars smaller 2nd primary molar • Must hold space (LLA) close to the time the 2nd primary molars exfoliate • Can’t use that space to correct molar relationship