title: Management of space problems in the primary and mixed dentitions.
abstract: BACKGROUND
  According to the Third National Health and Nutrition Examination Survey, crowding and irregularity remain a consistent problem for children. Management of space problems continues to play an important role in a dental practice. It also represents an area of major interaction between the primary provider and the specialists. This article attempts to update clinicians on the current knowledge of space management.
  Proper management of space in the primary and mixed dentitions can prevent unnecessary loss in arch length. Diagnosing and treating space problems requires an understanding of the etiology of crowding and the development of the dentition to render treatment for the mild, moderate and severe crowding cases. Most crowding problems with less than 4.5 millimeters can be resolved through preservation of the leeway space, regaining space or limited expansion in the late mixed dentition. In cases with 5 to 9 mm of crowding, some can be approached with expansion after thorough diagnosis and treatment planning. Most of these cases will require extraction of permanent teeth to preserve facial esthetics and the integrity of the supporting soft tissue. Serial extraction or guidance of eruption is reserved for treatment of severe tooth-size/arch-size discrepancies. Due to variations in the timing and extraction sequence depending on the diagnosis, serial extraction should be reserved for those who can complete the treatment successfully.
  
  
  CONCLUSIONS
  The recommended timing of referring patients with moderate crowding to specialists for treatment is in the late mixed-dentition stage of development. Patients with severe crowding will require earlier evaluation for serial extraction.
authors.affiliation: West Virginia University, School of Dentistry, Department of Orthodontics, Morgantown 26506, USA.
authors.forename: P
authors.initials: P
authors.lastname: Ngan
authors.forename: R G
authors.initials: RG
authors.lastname: Alkire
authors.forename: H
authors.initials: H
authors.lastname: Fields
mesh_terms: D000293:Adolescent; D002648:Child; D003818:Dentition, Mixed; D006801:Humans; D007180:Incisor / Q000033:anatomy & histology; D008310:Malocclusion / Q000175:diagnosis / Q000209:etiology / Q000628:therapy*; D009811:Odontometry; D010155:Palatal Expansion Technique; D012690:Serial Extraction; D013027:Space Maintenance, Orthodontic / Q000379:methods*; D014081:Tooth Extraction; D014094:Tooth, Deciduous