title: The hidden X suture: a technical note on a novel suture technique for alveolar ridge preservation.
abstract: OBJECTIVE
  The present study investigated the impact of 2 different suture techniques, the conventional crossed mattress suture (X suture) and the novel hidden X suture, for alveolar ridge preservation (ARP) with an open healing approach.
  
  
  METHODS
  This study was a prospective randomized controlled clinical trial. Fourteen patients requiring extraction of the maxillary or mandibular posterior teeth were enrolled and allocated into 2 groups. After extraction, demineralized bovine bone matrix mixed with 10% collagen (DBBM-C) was grafted and the socket was covered by porcine collagen membrane in a double-layer fashion. No attempt to obtain primary closure was made. The hidden X suture and conventional X suture techniques were performed in the test and control groups, respectively. Cone-beam computed tomographic (CBCT) images were taken immediately after the graft procedure and before implant surgery 4 months later. Additionally, the change in the mucogingival junction (MGJ) position was measured and was compared after extraction, after suturing, and 4 months after the operation.
  
  
  RESULTS
  All sites healed without any complications. Clinical evaluations showed that the MGJ line shifted to the lingual side immediately after the application of the X suture by 1.56±0.90 mm in the control group, while the application of the hidden X suture rather pushed the MGJ line slightly to the buccal side by 0.25±0.66 mm. It was demonstrated that the amount of keratinized tissue (KT) preserved on the buccal side was significantly greater in the hidden X suture group 4 months after the procedure (P<0.05). Radiographic analysis showed that the hidden X suture had a significant effect in preserving horizontal width and minimizing vertical reduction in comparison to X suture (P<0.05).
  
  
  CONCLUSIONS
  Our study provided clinical and radiographic verification of the efficacy of the hidden X suture in preserving the width of KT and the dimensions of the alveolar ridge after ARP.
authors.affiliation: Department of Periodontology, Dankook University College of Dentistry, Cheonan, Korea .
authors.forename: Jung-Chul
authors.identifier: 0000-0002-2041-8047
authors.initials: JC
authors.lastname: Park
authors.affiliation: Department of Periodontology, Seoul National University School of Dentistry, Seoul, Korea .
authors.forename: Ki-Tae
authors.identifier: 0000-0002-9809-2630
authors.initials: KT
authors.lastname: Koo
authors.affiliation: Department of Periodontology, Kyung Hee University School of Dentistry, Seoul, Korea .
authors.forename: Hyun-Chang
authors.identifier: 0000-0001-7695-1708
authors.initials: HC
authors.lastname: Lim
keywords: Alveolar process; Bone regeneration; Bone resorption; Suture techniques; Tooth extraction