Dynamic Navigation In Cases Of Critical Anatomy

Case Report

A 75-year-old male patient had endured a gap for five years, following removal of his lower left second molar, due to an acute apical infection. He was finding mastication increasingly difficult and sought advice about the treatment options available.

Planning for optimum implant positioning

As there was no tooth distal to the space, conventional fixed bridgework was not possible. The treatment options were either a unilateral single saddle lower partial denture or restoration of the space with two dental implants. The patient chose to have dental implant treatment as he did not wish to have any form of removable prosthesis.

What makes Navident dynamic navigation stand out is it precisely guides the surgeon to prepare and place the implant in a pre-determined position (Figure 1). This allows me to achieve greater accuracy and certainty than I have previously been able to, using conventional protocols. Whilst there is no physical guide, a simple scanning template (NaviStent) is used to hold the fiducial in place whilst taking the CT scan, and secure the jaw reference (JawTag) for the navigated osteotomy.

In this case, the Navistent was fabricated, the fiducial marker attached and a CBCT scan taken two weeks prior to surgery (Figure 2). The treatment plan was created immediately after the scan (Figure 3), with the patient present. He was able to see the proposed treatment displayed by the Navident software and appreciated that great care was being taken to achieve the optimum implant positioning, with minimal risk of potential complications (Figure 4). The patient was extremely impressed with, and reassured by, the state-of-the-art technology.

Confidence from continuous feedback Treatment was carried out under local anaesthesia. Prior to preparation of the implant sites, the simple Navident protocol for calibration and verification of the drill axis and drill tip was carried out. A crestal incision was made, with a minimal flap reflected. The software shows the drill position on the scan in real time, as it enters the jaw. This allows adjustments to be made, if necessary, whilst the site is being drilled. Two DENTSPLY ANKYLOS® CX 3.5mm diameter dental implants were placed sub-crestally in the lower left first and second molar sites, with implant lengths of 11mm and 9.5mm respectively.

Avoiding damage to the inferior alveolar nerve was a crucial factor in the treatment planning of this case. Access was difficult, due to the limited opening of the patient’s mouth. The issue was compounded by the plan to place an implant as distal as the second molar. These challenges were overcome using Navident’s continuous internal visual feedback, which gave me the confidence to use the optimum length of implant, whilst staying within a safe distance from the inferior alveolar nerve and avoiding post-surgical complications, such as paraesthesia.

Navident provided guidance for accurate implant location, even with restricted visibility and the drill being impeded by opposing teeth. Tactile feedback can often be reduced when using a physical drill guide. Dynamic navigation removes this obstacle. I was able to achieve the best buccal and lingual position of the implants, and their relation to each other and to adjacent teeth (Figure 5). This would allow for optimal shape, position and occlusal function of the final restorations.

ANKYLOS® Balance posterior sulcus formers were fitted and the incision was closed with simple interrupted sutures. There was no need for bone augmentation. Two to three months after surgery, the implants will be restored with ATLANTIS® custom-made CAD/CAM titanium abutments and screw-retained linked zirconia crowns.

The clinical outcome was excellent. The planned placement was restoratively driven and the implants were well positioned, with good primary stability. Having used the Navident dynamic navigation system for more than a year, I would not want to go back to preparing and placing dental implants without its 3D visual guidance. The patient was comfortable and reassured, with no post-operative pain, swelling, bruising or paraesthesia. He was delighted and, if he needed any implant treatment in the future, would insist on dynamic navigation.

About Dr David Burgess BDS DPDS MScConSed

David Burgess has been principal of Carbis Bay Dental Care in Cornwall since 1988 and has placed over 2,000 implants. Throughout his career, David has striven to combine clinical perfection with the ultimate in patient care. He has been a willing pioneer of new technology, particularly in the field of digital dentistry. David was the first UK clinician to introduce the Navident dynamic navigation system into his implant treatment workflow, with the objective of achieving a higher degree of precision and greater patient comfort.

David Burgess is also a member of the Dynamic Navigation Society as a Master Clinical Trainer, providing courses for implantologists who wish to experience how dynamic navigation can help to simplify their digital workflow. More information can be found on http://dns.claronav.com