Remodeling of Autogenous Bone Grafts after Osteotome Sinus Floor Elevation Assessed by Limited Cone Beam Computed Tomography
Remodeling of Autogenous Bone Grafts after Osteotome Sinus Floor Elevation Assessed by Limited Cone Beam Computed Tomography
Tetsuya Nishida,1,2 Yuka Takenouchi,1 Kyoko Mori,1,3 Miyuki Ariji,1,3 Kaori Nishida,3,4 and Koichi Ito3
1Department of Periodontology, Nihon University School of Dentistry, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan
2Division of Advanced Dental Treatment, Dental Research Center, Nihon University School of Dentistry, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan
3Ark Dental Clinic, 1-5 Rokubancho, Chiyoda-ku, Tokyo 102-0085, Japan
4Nihon University School of Dentistry, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan
Received 27 April 2013; Accepted 19 June 2013
Academic Editor: Eiichiro Ariji
Copyright © 2013 Tetsuya Nishida et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
This study assessed the radiographic appearance of bone graft domes longitudinally after osteotome sinus floor elevation using cone beam computed tomography (CBCT). This study presents the radiological findings of a 6-month follow-up CBCT study in maxillary osteotome sinus floor elevation. We examined 52 patients with a crestal bone height of less than 8 mm in the posterior maxilla who required sinus augmentation. Implants ( ) were subsequently placed in regenerated bone following osteotome sinus floor elevation; autogenous bone was used as the augmentation material. In all cases, the grafted augmentation material tended to be absorbed, but at least 1 mm of grafted augmentation material was recognized around the implant fixtures on CBCT at the second implant operation. The border between the grafted augmentation material and the existing bone was indistinct. The grafted area apical to the implants undergoes shrinkage and remodeling. It was suggested that sufficient grafted autogenous bone changes into bone to support an implant.
1. Introduction
Alveolar bone resorption of the maxillary posterior edentulous region and increased pneumatization of the sinus cavity can result in insufficient bone support for dental implants. This problem can be overcome by grafting the maxillary sinus floor using a sinus lift procedure [1–12]. A prerequisite for this procedure is separating the intact sinus membrane from the maxillary sinus floor. The periosteal portion of this membrane has few elastic fibers, making the separation a relatively simple and reliable procedure. As a result, the posterior maxilla is one of the most predictably successful areas for bone grafting procedures [13]. Numerous articles describe this procedure detailing bone grafting materials, long-term clinical follow-up of bone consolidation, and implant success [1–12]. Complications following a sinus lift procedure include maxillary sinusitis, oroantral communication, bone graft resorption, mucocele formation, maxillary cyst, and implant failure [14].
Currently, two main approaches to the maxillary sinus floor elevation procedure can be found in the literature. The first approach, lateral antrostomy, is the classical and more commonly performed technique, originally described by Tatum [15]. The lateral antrostomy technique, also referred to as the Caldwell-Luc or lateral window approach, involves creating a window in the lateral wall of the maxillary sinus to permit visualization of the Schneiderian membrane during its elevation in preparation for site grafting. More recently, Summers advocated a second approach, the crestal approach, using osteotomes [16–18]. The osteotome technique takes advantage of the fact that bone is viscoelastic and can be compressed and manipulated. Bone compaction, cortical sinus floor elevation, and ridge expansion can be performed using the technique, which has been evaluated in several clinical studies [19–25].
Recently, a new compact computed tomography (CT) system, known as ortho cubic super-high-resolution CT, was developed. Limited cone beam CT (CBCT) provides three-dimensional (3D) information. A restriction with conventional radiographic methods is the limited two-dimensional (2D) information they provide. For the complete assessment of the grafted dome-shaped bone graft after an osteotomy, a 3D evaluation method is required. The aim of this study was to longitudinally assess the radiographically appearing bone graft domes after osteotomy using CBCT.
2. Material and Methods2.1. Patient Selection
All patients with a crestal bone height of less than 8 mm in the posterior maxilla who required sinus augmentation were chosen from those seen at Nihon University School of Dentistry Dental Hospital, Tokyo, Japan, after evaluating their medical histories and conducting thorough dental examinations between February 2003 and July 2011.
2.2. Sinus Lift Procedure Technique
The osteotome sinus floor elevation (...truncated)