Reduced Arch Length as a Factor for 4-Implant Immediate Function in the Maxilla: A Technical Note and Report of 39 Patients Followed for 5 Years

Abstract

To determine whether maxillary arch length deficiency treated with a V-4 implant placement method is adequate for immediate functional loading during a 5-year follow-up. Thirty-nine patients were treated with maxillary immediate function from January 3, 2011 to February 28, 2011 and followed for a period of 5years. Arch length after implant placement was measured retrospectively around the arch from the anterior sinus wall to the contralateral anterior sinus wall in a mid-alveolar arc on the occlusal view of the preoperative computed tomogram. Eight patients with an osseous arch length shorter than 45mm were treated with a V-4 pattern. Thirty-one patients with an arch length longer than 45mm were treated with an M-4 placement pattern. The aim was to determine whether immediate function with a shorter arch length could be obtained on the day of surgery using a V-4 placement and whether implant stability would persist during the 5-year follow-up. Any surgical events, including lost implants, were recorded in the charts. Late follow-up was performed by panoramic films. During the 2-month treatment period, 39 patients (8 with V-4 placement and and 31 with M-4 placement) received maxillary treatment. The 8 patients in the V-4 group had an arch length average of 36.0mm available for osseointegration. The 31 patients in the M-4 group had an arch length average of 56.6mm. There were 7 implant losses (and replacements) during the 5-year follow-up, 1 in the V-4 group and 6 in the M-4 group. When the arch length bone available for osseointegration is shorter than 45mm, a V-4 placement strategy might enable successful 4-implant fixed denture support for immediate function.