title: Expansion of Mandibular Knife-Edge Ridge and Simultaneous Implant Placement to Retain Overdentures: One-Year Clinical and Radiographic Results of a Prospective Study.
abstract: OBJECTIVE
  The aim of this study was to evaluate and compare the clinical and radiographic outcomes of two implants placed in expanded mandibular knife-edge ridge and implants placed in unexpanded ridges to retain overdentures.
  
  
  METHODS
  Fifteen completely edentulous patients with knife-edge ridges at canine areas of the mandible received two implants using the ridge expansion technique (study group, SG). Expansion was performed using piezoelectric corticotomy, and self-threading expanders. The control group (CG) comprised patients who received two-implant at canine areas without ridge expansion but were all case matched to SG and served as historical cohort. In both groups, mandibular overdentures were connected to the implants with Locator attachments 3 months after implant placement. Clinical (Plaque index; PI, Gingival index; GI, Probing depth; PD, and implant stability; ISQ) and radiographic (Vertical bone loss; VBL) parameters were recorded at time of overdenture insertion (base line, T0), 6 months (T6), and 12 months (T12) after insertion.
  
  
  RESULTS
  The cumulative success rates were 100% and 96.4% for CG and SG, respectively, without significant difference between groups. All tested parameters increased significantly with advance of time in both groups. There was no significant difference in PI, GI, PD, and ISQ between groups. However, SG recorded significant higher VBL than CG at T6 and T12.
  
  
  CONCLUSIONS
  Expansion of mandibular knife edge ridge and simultaneous placement of implants to retain overdentures is associated with clinic and radiographic outcomes comparable to implants placed in unexpanded ridges after 1 year. However, long term randomized controlled trials with sufficient sample size are still needed to ensure the findings of the present study.
authors.affiliation: Faculty of Dentistry, Associate Professor, Removable Prosthodontics, Department of Removable Prosthodontic, Mansoura University, Eldakahlia, Egypt.
authors.forename: Moustafa Abdou
authors.initials: MA
authors.lastname: ELsyad
authors.affiliation: Associate Professor of Oral Surgery, Faculty of Dentistry, Mansoura University, Egypt.
authors.forename: Nelly Ibrahim
authors.initials: NI
authors.lastname: Hammouda
mesh_terms: D000328:Adult; D000368:Aged; D000540:Alveolar Ridge Augmentation / Q000379:methods*; D003758:Dental Implantation, Endosseous; D019094:Dental Prosthesis, Implant-Supported; D003834:Denture Precision Attachment; D003781:Denture Retention; D003828:Denture, Overlay; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008297:Male; D009066:Mouth, Edentulous / Q000000981:diagnostic imaging / Q000601:surgery*; D011183:Postoperative Complications / Q000000981:diagnostic imaging*; D011446:Prospective Studies; D019252:Radiography, Dental, Digital; D011862:Radiography, Panoramic; D000074269:Resonance Frequency Analysis
keywords: implant; knife-edge ridge; mandibular; overdentures; ridge expansion