Facial divergence and mandibular crowding in treated subjects.
OBJECTIVE
To understand the relationships between facial divergence, vertical growth, and postretention mandibular crowding.


METHODS
Seventy-five white extraction patients were evaluated immediately posttreatment (15.4 years) and again 16.6 years later. Hyperdivergent subjects, subjects with open bite or severe deep bites were not evaluated. Changes in incisor irregularity and tooth-size arch-length discrepancies (TSALD) were evaluated and correlated with measures of divergence and skeletal growth.


RESULTS
Incisor irregularity increased 0.9 mm and TSALD increased 0.7 mm after treatment; 68% of the subjects had less than 3.5 mm incisor irregularity at postretention. Male patients showed significantly more growth than female patients did. Female patients, who were significantly more hyperdivergent than male patients, showed weak to moderately weak associations between posttreatment facial divergence and crowding. Female posttreatment changes in anterior face height, lower incisor eruption, and changes in arch depth were also related to crowding; male patients showed moderate relationships between posttreatment changes in arch width and crowding.


CONCLUSIONS
Greater vertical growth, incisor eruption, and especially facial divergence are related to greater posttreatment mandibular crowding.
Department of Orthodontics, Center for Advanced Dental Education, Saint Louis University, St Louis, MO, USA.
Avrum I
AI
Goldberg
R G
RG
Behrents
Donald R
DR
Oliver
Peter H
PH
Buschang
D000293:Adolescent; D000328:Adult; D002508:Cephalometry; D003724:Dental Arch / Q000254:growth & development*; D005260:Female; D006801:Humans; D008297:Male; D008310:Malocclusion / Q000628:therapy*; D008334:Mandible / Q000254:growth & development*; D008445:Maxillofacial Development / Q000502:physiology*; D003765:Models, Dental; D009971:Orthodontics, Corrective / Q000379:methods*; D012737:Sex Factors; D018709:Statistics, Nonparametric; D014716:Vertical Dimension