Real-Time Dynamic Navigation System for the Precise Quad-Zygomatic Implant Placement in a Patient with a Severely Atrophic Maxilla

Summary

Here, we present a protocol to achieve precise quad-zygomatic implant placement in patients with severely atrophic maxilla using a real-time dynamic navigation system.

Abstract

Zygomatic implants (ZIs) are an ideal way to address cases of a severely atrophic edentulous maxilla and maxilla defects because they replace extensive bone augmentation and shorten the treatment cycle. However, there are risks associated with the placement of ZIs, such as penetration of the orbital cavity or infra-temporal fossa. Furthermore, the placement of multiple ZIs makes this surgery risky and more difficult to perform. Potential intraoperative complications are extremely dangerous and may cause irreparable losses. Here, we describe a practical, feasible, and reproducible protocol for a real-time surgical navigation system for precisely placing quad-zygomatic implants in the severely atrophic maxilla of patients with residual bone that does not meet the requirements of conventional implants. Hundreds of patients have received ZIs at our department based on this protocol. The clinical outcomes have been satisfactory, the intraoperative and postoperative complications have been low, and the accuracy indicated by infusion of the designed image and postoperative three-dimensional image has been high. This method should be utilized during the entire surgical procedure to ensure ZI placement safety.

Introduction

In the 1990s, Branemark introduced an alternative technique for bone grafting, the zygomatic implant (ZI), which has also been called the zygomaticus fixture¹. It was initially used for the treatment of trauma victims and patients with tumor resection where there was a defect in the maxillary structure. After maxillectomy, many patients retained anchorage only in the body of the zygoma or in the frontal extension of the zygomatic bone^1,2,3.

More recently, the ZI technique has been widely used in edentulous and dentate patien....

Protocol

All of the clinical protocols were approved by the Medical Ethics Review Committee of the Shanghai Ninth People's Hospital, Shanghai Jiao Tong University, School of Medicine (SH9H-2020-T29-3).

1. Patient selection

1. The patient inclusion criteria were as follows (Table 1).
   1. Ensure that the patient presents a completely edentulous maxilla or partially edentulous maxilla with few extremely loose teeth (Figure 1A-G).
   2. Ensure that the patient has severe atrophy of the maxilla and insufficient bone volume for conventional implant p....

Results

The enrolled patient was a 60-year-old woman without any systematic diseases (Figure 1A-D, F). After CBCT scanning, the alveolar ridge in the anterior maxilla was less than 2.9 mm, while the residual bone height in the posterior maxilla region was less than 2.4 mm (Figure 1E, G and Table 1). The width and thickness of the zygomatic bone were approximately 22.4-23.6 mm and 6.1-8.0 mm (

Discussion

Reconstructive rehabilitation of the atrophic maxilla using grafts is difficult because it requires good surgical technique, coverage of high-quality soft tissue over the graft, a significant amount of patient cooperation, and patients with health favorable for the finial restoration^17,18. The placement of dental implants for reconstruction in patients with maxillary atrophy represents a significant clinical challenge. The pattern of facial bone resorption is ass.......

Materials

Name	Company	Catalog Number	Comments
Bistoury scalpel	Hufriedy Group	10-130-05
Branemark system zygoma TiUnite RP 35mm	Nobel Biocare AB	34724	TiUnite implant with overlength to place from the maxilla to the zygoma
Branemark system zygoma TiUnite RP 40mm	Nobel Biocare AB	34735	TiUnite implant with overlength to place from the maxilla to the zygoma
Branemark system zygoma TiUnite RP 42.5mm	Nobel Biocare AB	34736	TiUnite implant with overlength to place from the maxilla to the zygoma
Branemark system zygoma TiUnite RP 45mm	Nobel Biocare AB	34737	TiUnite implant with overlength to place from the maxilla to the zygoma
Branemark system zygoma TiUnite RP 47.5mm	Nobel Biocare AB	34738	TiUnite implant with overlength to place from the maxilla to the zygoma
Branemark system zygoma TiUnite RP 50mm	Nobel Biocare AB	34739	TiUnite implant with overlength to place from the maxilla to the zygoma
Branemark system zygoma TiUnite RP 52.5mm	Nobel Biocare AB	34740	TiUnite implant with overlength to place from the maxilla to the zygoma
CBCT	Planmeca Oy,Helsinki, Finland	Pro Max 3D Max
connection to handpiece	Nobel Biocare AB	29081	the accessories to connect the intrument
Drill guard	Nobel Biocare AB	29162	the accessories to protect the lips and soft tissue during the surgery
Drill guard short	Nobel Biocare AB	29162	the accessories to protect the lips and soft tissue during the surgery
Handpiece zygoma 20:1	Nobel Biocare AB	32615	the basic instrument for implant drill
Instrument adapter array size L	BRAINLAB AG	41801
Instrument adapter array size M	BRAINLAB AG	41798
Instrument calibration matrix	BRAINLAB AG	41874	a special tool for drill to calibration
I-plan automatic image fusion software STL data import/export for I-plan VectorVision2®, (I-plan CMF software)	BRAINLAB AG	inapplicability	the software for navigation surgery planning
Multi-unit abutment 3mm	Nobel Biocare AB	32330	the connection accessory between the implant and the titanium base
Multi-unit abutment 5mm	Nobel Biocare AB	32331	the connection accessory between the implant and the titanium base
Periosteal elevator	Hufriedy Group	PPR3/9A	the instrument for open flap surgery
Pilot drill	Nobel Biocare AB	32630	the drill for the surgery
Pilot drill short	Nobel Biocare AB	32632	the drill for the surgery measuring the depth of the implant holes
Pointer with blunt tip for cranial/ENT	BRAINLAB AG	53106
Reference headband star	BRAINLAB AG	41877
Round bur	Nobel Biocare AB	DIA 578-0	the drill for the surgery
Screwdriver manual	Nobel Biocare AB	29149
Skull reference array	BRAINLAB AG	52122	a special made metal reference for navigation camera to receive the signal
Skull reference base	BRAINLAB AG	52129
Suture vicryl 4-0	Johnson &Johnson, Ethicon	VCP310H
Temporary copping multi-unit titanium (with prosthetic screw)	Nobel Biocare AB	29046	the temporary titanium base to fix the teeth
Titanium mini-screw	CIBEI	MB105-2.0*9	the mini-screw for navigation registration
Twist drill	Nobel Biocare AB	32628	the drill for the surgery
Twist drill short	Nobel Biocare AB	32629	the drill for the surgery
Zygoma depth indicator angled	Nobel Biocare AB	29162
Zygoma depth indicator straight	Nobel Biocare AB	29162	the measurement scale for
Zygoma handle	Nobel Biocare AB	29162	the instrument for zygomatic implant placement