Journal of Oral Implantology April 2013 - (Page 215)

LITERATURE REVIEW Zygomatic Implants/Fixture: A Systematic Review Ashu Sharma, MDS* G. R. Rahul, MDS Patients with moderate to severe atrophy challenge the surgeon to discover alternative ways to use existing bone or resort to augmenting the patient with autogenous or alloplastic bone materials. Many procedures have been suggested for these atrophied maxillae before implant placement, which include Le Fort I maxillary downfracture, onlay bone grafts and maxillary sinus graft procedures. A zygomatic implant can be an effective device for rehabilitation of the severely resorbed maxilla. If zygomatic implants are used, onlay bone grafting or sinus augmentation would likely not be necessary. The purpose of this article is to review the developments that have taken place in zygomatic implant treatment over years, including anatomic information for installing the zygomatic implants, implant placement techniques, stabilization, and prosthodontic procedures. Key Words: zygomatic bone, zygomatic implants, severely resorbed maxilla, zygomatic fixtures, maxillary sinus INTRODUCTION E ndosseous implants have become a very common mode of treatment for partially and completely edentulous patients, thanks to the process of osseointegration of endosseous implants with the surrounding bone. Unfortunately, restrictions have appeared in the use of oral implants. One of them is the lack of sufficient bone volume, especially in the posterior maxilla. This insufficient bone volume can be due to bone resorption as well as to pneumatization of the sinus or to a combination of both.1 According to some clinical reports, the minimal bone height for a standard implant in the posterior region should be at least 10 mm to ensure acceptable success rate.2 With the introduction of wide implants, 5 and 6 mm in diameter,3,4 the contact surface between implant and bone is increased and assumes a cortical anchorage with an initial stability in type IV bone even if the bone height is no greater than 6 mm. Implants of wide diameter limit the biomechanical complications in Department of Prosthodontics, Bangalore Institute of Dental Sciences and Research Center, Bangalore, Karnataka, India. * Corresponding DOI: 10.1563/AAID-JOI-D-11-00055 the treatment of the posterior maxillae. Pterygomaxillary implants have also been proposed for posterior anchorage in totally edentulous patients.5 Many alternative procedures have then been studied to treat atrophic maxilla, such as the use of composite grafts,6 Le Fort I osteotomy,7 iliac crest grafts,8,9 and maxillary sinus grafts.10 Distraction osteogenesis is a quite new procedure for bone augmentation. However, no publication concerning bone lengthening in the posterior severely resorbed maxilla could be found related to this new procedure.1 From experience based on animal research and human experiments, Branemark et al,11 knowing that the introduction of an implant in the sinus would not necessarily jeopardize sinus health, considered using the zygoma bone as an anchorage for prosthetic rehabilitation in hemimaxillectomy patients as well as for other defects. As these reconstructions12 were successful and long-term stability of these implants was established, in 1997 Branemark developed a specific implant called the zygomaticus fixture to provide fixed solutions even when the conditions for implant insertion were poor in the posterior maxilla. This new technologic development offers alternatives to bone grafting or sinus-lifting procedures, which involve rather invasive surgery.1 Journal of Oral Implantology 215

Table of Contents for the Digital Edition of Journal of Oral Implantology April 2013

Evidence-Based Practice or Practice-Based Evidence?
Evaluation of Optimal Taper of Immediately Loaded Wide-Diameter Implants: A Finite Element Analysis
A Prospective, Randomized Controlled Preclinical Trial to Evaluate Different Formulations of Biphasic Calcium Phosphate in Combination With a Hydroxyapatite Collagen Membrane to Reconstruct Deficient Alveolar Ridges
Retention of Implant-Supported Overdenture With Bar/Clip and Stud Attachment Designs
The Clinical and Histologic Outcome of Dental Implant in Large Ridge Defect Regenerated With Alloplast: A Randomized Controlled Preclinical Trial
Fluoride-Treated Bio-Resorbable Synthetic Hydroxyapatite Promotes Proliferation and Differentiation of Human Osteoblastic MG-63 Cells
Resonance Frequency Analysis of 208 Straumann Dental Implants During the Healing Period
A Simplified Technique for Solving the Transfer Problem of Implant-Supported Fixed Partial Dentures for Patients With Microstomia
Esthetic Evaluation of Single-Tooth Morse Taper Connection Implants Placed in Fresh Extraction Sockets or Healed Sites
A Technique for Improving the Retention of Dentures Retained by Ramus Frame Implants
Treatment of Congenitally Missing Maxillary Lateral Incisors: An Interdisciplinary Approach
Use of Titanium Mesh in Lieu of a Fixation Screw to Stabilize an Autogenous Block Graft: A Case Report
A Novel Approach to Preserve the Buccal Wall in Immediate Implant Cases: A Clinical Report
Implant Failure Associated With Actinomycosis in a Medically Compromised Patient
Replacement of Mandibular Posterior Teeth With Implants in a Postmandibular Resection Case: A Case Report
Zygomatic Implants/Fixture: A Systematic Review
An Overview of Immediate Root Analogue Zirconia Implants
Letter to the Editor
Reviews of Current Literature

Journal of Oral Implantology April 2013