title: Gingival crevicular fluid alkaline phosphate activity during the retention phase of maxillary expansion in prepubertal subjects: A split-mouth longitudinal study.
abstract: BACKGROUND
  The aim of this study was to monitor the alveolar bone formation at the tension sites of teeth supporting the appliances for rapid maxillary expansion (RME) during the retention phase according to the local gingival crevicular fluid (GCF) alkaline phosphatase (ALP) activity.
  
  
  METHODS
  This split-mouth prospective study included 23 prepubertal subjects (15 girls, 8 boys; mean age, 9.0 ± 1.4 years) who had a constricted maxillary arch and were undergoing RME. Periodontal parameters, including probing depth, were recorded at 3 and 6 months after RME. Furthermore, the GCF ALP activity was measured at the tension sites of the supporting test teeth (TT) and at the antagonist control teeth (CT) sites.
  
  
  RESULTS
  Periodontal parameters were generally similar between the TT and CT sites during the study, with the exception that probing depth underwent a slight increase at the TT sites. At baseline, the GCF ALP activity was similar between the TT and CT sites; however, at both 3 and 6 months, significantly greater enzymatic activity was seen at the TT sites. The overall probing depth changes were not significantly correlated with the corresponding GCF ALP activity changes for either the TT or the CT sites.
  
  
  CONCLUSIONS
  Alveolar bone formation at the tension sites would last up to 6 months of retention after RME. These results warrant more comprehensive studies to assess whether the GCF ALP activity has potential as a diagnostic tool for bone formation during the retention phase of RME.
authors.affiliation: Research fellow, Department of Medical, Surgical and Health Sciences, University of Trieste, Trieste, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Perinetti
authors.affiliation: Research fellow, Department of Orthodontics, Second University of Naples, Naples, Italy.
authors.forename: Fabrizia
authors.initials: F
authors.lastname: D'Apuzzo
authors.affiliation: Assistant professor, Department of Medical, Surgical and Health Sciences, University of Trieste, Trieste, Italy. Electronic address: l.contardo@fmc.units.it.
authors.forename: Luca
authors.initials: L
authors.lastname: Contardo
authors.affiliation: Assistant professor, Department of Orthodontics and Jaw Orthopaedics, Medical Faculty, University of Ljubljana, Ljubljana, Slovenia.
authors.forename: Jasmina
authors.initials: J
authors.lastname: Primozic
authors.affiliation: Research fellow, Department of Medical, Surgical and Health Sciences, University of Trieste, Trieste, Italy.
authors.forename: Katia
authors.initials: K
authors.lastname: Rupel
authors.affiliation: Professor, Department of Orthodontics, Second University of Naples, Naples, Italy.
authors.forename: Letizia
authors.initials: L
authors.lastname: Perillo
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism*; D015415:Biomarkers / Q000378:metabolism; D001846:Bone Development; D002648:Child; D005260:Female; D005883:Gingival Crevicular Fluid / Q000201:enzymology*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D010155:Palatal Expansion Technique; D011446:Prospective Studies
chemical_list: D015415:Biomarkers; D000469:Alkaline Phosphatase