title: Stability of Vertical, Horizontal and Angular Parameters Following Superior Repositioning of Maxilla by Le Fort I Osteotomy: A Cephalometric Study.
abstract: BACKGROUND
  The restoration of normal jaw function, optimal facial aesthetics and long term stability are the goals of any orthognathic surgical procedures. During the last two decades, several cephalometric investigations have been reported on the skeletal changes following maxillary surgical procedures. The stability following LeFort I osteotomy and maxillary superior repositioning of the maxilla has not been studied extensively.
  
  
  OBJECTIVE
  This study was aimed at determining the surgical changes brought about by superior repositioning of the maxilla by Le Fort I osteotomy and evaluate the stability of the surgical procedure one year following surgery.
  
  
  METHODS
  Presurgical and postsurgical and one year post surgical lateral cephalograms of 10 adult patients (age group - 17 to 40 years, with a mean age of 22.2 years) who had been treated successfully by maxillary Le-Fort I osteotomy and impaction were obtained. The lateral cephalograms were grouped into three categories: T1- Presurgical, T2- Postsurgical, T3- One year postsurgical. Comparisons were made between T1-T2 and T2-T3 to assess the changes following surgery and to evaluate the stability, one year following the surgery using 5 horizontal, 5 vertical linear and 2 angular measurement. Statistical analysis was done with SPSS (Version 17). Results were expressed as mean±standard deviation. A paired t-test was used to analyze the paired observations.
  
  
  RESULTS
  The difference between T1 and T2 values of vertical changes showed that they were statistically highly significant whereas from T2 to T3 they were insignificant. The difference between T1 and T2 values of all the horizontal changes showed that they were statistically significant whereas True Vertical Line (TVL) to point Anterior Nasal Spine (ANS) was not statistically significant. The horizontal changes from T2 to T3 were statistically not significant whereas TVL to point Incisal edge of upper incisor (Is) was statistically significant. The angular changes from T1 to T2, T2 to T3 were statistically not significant.
  
  
  CONCLUSIONS
  There was a significant reduction in the facial height and significant anterior movement of maxilla after surgery. Even after one year of surgery, negligible amount of relapse was recorded except at the incisors.
authors.affiliation: Assistant Professor, Department of Dentistry, BGS Global Institute of Medical Sciences , Bengaluru, Karnataka, India .
authors.forename: Pruthvi Raj Hanthur
authors.initials: PR
authors.lastname: Venkategowda
authors.affiliation: Professor, Department of Orthodontics, Bapuji Dental College , Davengere, Karnataka, India .
authors.forename: A T
authors.initials: AT
authors.lastname: Prakash
authors.affiliation: Professor, Department of Orthodontics, Bapuji Dental College , Davengere, Karnataka, India .
authors.forename: E T
authors.initials: ET
authors.lastname: Roy
authors.affiliation: Professor and Head, Department of Orthodontics, Bapuji Dental College , Davengere, Karnataka, India .
authors.forename: K Sadashiva
authors.initials: KS
authors.lastname: Shetty
authors.affiliation: Consultant, Department of Orthodontics, Puri's Skin and Dental Clinic , Delhi, India .
authors.forename: Surbhi
authors.initials: S
authors.lastname: Thakkar
authors.affiliation: Dental Officer, Department of Orthodontics, Corps Dental Unit , Bhopal, Madhya Pradesh, India .
authors.forename: Rajkumar
authors.initials: R
authors.lastname: Maurya
keywords: Bi-maxillary surgery; Long term relapse; Skeletal Class II malocclusion