title: Flap extension attained by vertical and periosteal-releasing incisions: a prospective cohort study.
abstract: OBJECTIVE
  To evaluate the effect of vertical and periosteal-releasing incisions (PRI) on the extension of the buccal flap in a trapezoidal flap design.
  
  
  METHODS
  Thirty patients scheduled for implant surgery accompanied by bone augmentation were recruited. The amount of flap extension pulled with a minimal tension of 5 g using a dynamometer was measured before and after the first and the second vertical incisions (VI) and PRI. The results were compared based on gender, surgical site and operator's experience.
  
  
  RESULTS
  The first VI extended flap length by 1.1 ± 0.6 mm, 113.4% more compared with the original flap length. The second VI increased flap length by 1.9 ± 1 mm (124.2%), and the PRI significantly extended flap length by 5.5 ± 1.5 mm (171.3%) (P<0.001). The length of the first and the second VI and the amount of flap extension by each incision were compared, and there were no statistically significant differences between gender, surgical site (maxilla vs. mandible) and operator's experience (faculty vs. residents).
  
  
  CONCLUSIONS
  Vertical and PRI in a trapezoidal flap design can be successfully utilized to attain tension-free primary closure during implant or periodontal surgeries. However, the PRI appears to be the only determinant key factor that can significantly extend the length of the flaps, while host- and operator-related factors might not have any significant effect on such flap extension.
authors.affiliation: Department of Periodontology, Research Institute for Periodontal Regeneration, College of Dentistry, Yonsei University, Seodaemun-gu, Seoul, Korea.
authors.forename: Jung-Chul
authors.initials: JC
authors.lastname: Park
authors.forename: Chang-Sung
authors.initials: CS
authors.lastname: Kim
authors.forename: Seong-Ho
authors.initials: SH
authors.lastname: Choi
authors.forename: Kyoo-Sung
authors.initials: KS
authors.lastname: Cho
authors.forename: Jung-Kiu
authors.initials: JK
authors.lastname: Chai
authors.forename: Ui-Won
authors.initials: UW
authors.lastname: Jung
mesh_terms: D000540:Alveolar Ridge Augmentation / Q000379:methods*; D003758:Dental Implantation, Endosseous; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010521:Periosteum / Q000601:surgery*; D011446:Prospective Studies; D013524:Surgical Flaps