title: Effect of low-level laser therapy (GaAlAs) on bone regeneration in midpalatal anterior suture after surgically assisted rapid maxillary expansion.
abstract: OBJECTIVE
  The aim of this study was to evaluate the effects of laser therapy on bone regeneration in the midpalatal anterior suture (MPAS) after surgically assisted rapid maxillary expansion (SARME).
  
  
  METHODS
  Thirteen patients aged between 18 and 33 years old with maxillary transverse deficiency (> or =7.0 mm) were evaluated. All patients underwent subtotal Le Fort I osteotomy with separation of the pterygomaxillary suture with the use of Hyrax expander, and were divided into 2 groups: control group (n = 6) and laser group (n = 7). A GaAlAs laser (P = 100 mW, lambda = 830 nm, Ø = 0.06 cm(2)) was used. The laser was applied in 8 treatment sessions with intervals of 48 hours. Each treatment session consisted of laser applications, per point (E = 8.4J, ED = 140J/cm(2)), at 3 points on the MPAS, and total dose of E = 25.2 J, ED = 420 J/cm(2). Digital radiographs were taken before the surgical procedure and at 1-, 2-, 3-, 4-, and 7-month follow-up visits. Optical density analysis of the regenerated bone was performed using Adobe Photoshop 8.0 software.
  
  
  RESULTS
  Bone regeneration associated with the use of laser after SARME showed a statistically significant difference. A higher mineralization rate was found in the laser group (26.3%, P < .001) than the control group.
  
  
  CONCLUSIONS
  Low-level laser irradiation (GaAlAs) accelerates bone regeneration in MPAS after SARME. However, the optical density measurements after 7 months of follow-up were lower in comparison with the preoperative measurements.
authors.affiliation: Division of Plastic Surgery, Federal University of São Paulo, São Paulo, Brazil.
authors.forename: Pierangelo
authors.initials: P
authors.lastname: Angeletti
authors.forename: Max Domingues
authors.initials: MD
authors.lastname: Pereira
authors.forename: Heitor Carvalho
authors.initials: HC
authors.lastname: Gomes
authors.forename: Claudia Toyama
authors.initials: CT
authors.lastname: Hino
authors.forename: Lydia Masako
authors.initials: LM
authors.lastname: Ferreira
mesh_terms: D000293:Adolescent; D000328:Adult; D015519:Bone Density / Q000528:radiation effects; D001861:Bone Regeneration / Q000528:radiation effects*; D016022:Case-Control Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D054023:Lasers, Semiconductor / Q000627:therapeutic use; D028022:Low-Level Light Therapy / Q000295:instrumentation / Q000379:methods*; D008297:Male; D008437:Maxilla / Q000000981:diagnostic imaging / Q000528:radiation effects / Q000601:surgery*; D019340:Osteotomy, Le Fort; D010155:Palatal Expansion Technique; D021362:Palate, Hard / Q000000981:diagnostic imaging / Q000528:radiation effects / Q000601:surgery*; D011859:Radiography; D015203:Reproducibility of Results; D018709:Statistics, Nonparametric; D016896:Treatment Outcome; D055815:Young Adult