Long (zygomatic) Implants as a last resort

Long implants:

The last resort

Luc vrielinck, Oral and MF Surgeon, Genk, Belgium

[email protected]

What are long implants?

Volume of

Zygoma bone:

2 x 2 x 2 cm

Overview

• Indications

• Techniques for long implants

• Clinical examples

Indications for long implants

• Terminal bone atrophy

• Failures of previous reconstructive procedures

• Defects (congenital, acquired, posttraumatic)

Long implants = end of the line in treatment modalities

What is terminal bone atrophy?

• Classification of bone atrophy

• How do we diagnose terminal bone

atrophy?

• Overview af treatment modalities with

advancing atrophy

The Misch Classification of bone resorption

A B B-w C-w C-h D

↓ Width ↓ Height

From: Dental Implant Prosthetic, Carl Misch

Misch classification

• Relates degree of bone atrophy to time

elapsed since extractions

• Allows a comparison of comparable cases

in the literature

• Resorption can be „modulated‟ by a

number of factors resulting in accelerated

resorption




atrophy?


advancing atrophy

Measuring = knowing: the bone table

H: 13.81 mm

W: 7.27 mm

Example : Bone table

Bone Table

• Principle:

– For each implant location

– Measure height and width

– Take into account eventual alveolectomy

– Compare measured values against minimum

required bone volume

– E.g. Height 10 mm; Width 6 mm

16 15 14 13 12 11

21 22 23 24 25 26

Bone table for the Upper Jaw

16 15 14 13 12 11 21 22 23 24 25 26

Hgt - 3.1 2.0 3.1 3.3 3.6 5.7 5.2 5.9 4.8 3.4 1.7

Th - 2.0 1.8 3.4 3.5 3.6 4.3 4.3 4.9 3.76 3.1 1.9




atrophy?


advancing atrophy

Typical treatment strategies with

increasing bone atrophy

Div A Div B Div C Div D

A B B-w C-w C-h D

Standard implants

All-on-4

Sinus lift

Short

Zygoma

Standard implants

Tilted implants

Sinus lifting

Short implants

Standard + Long implants

2RP-4 RP 2Z

Standard + Long implants

19/06/2010: Preïmplantaat

Quad zygoma

Quad zygoma

Overview

• Indications



Techniques for long implants

• Intrasinusal (Brånemark)

• Stella

• Extramaxillary

• Quad zygoma

• Pterygoid implants

• Skullbase implants

Intrasinusal zygoma


• Intrasinusal (Bränemark)

• Stella

• Extramaxillary

• Quad zygoma



Anterior slot technique



• Stella

• Extramaxillary

• Quad zygoma



Extramaxillary



• Stella

• Extramaxillary

• Quad zygoma



Quad zygoma



• Stella

• Extramaxillary

• Quad zygoma



Pterygoid / Sphenoid



• Stella

• Extramaxillary

• Quad zygoma



Skull base

To guide or not to guide?

• Mental navigation

• Drill guide surgery

• Navigation technique

Mental Navigation

• Surgery is simulated on 3D software

• Performed freehand by the surgeon using

surgical skill and 3D knowledge of the

surgeon

Drill guide

• Types:

– SurgiGuide™ (Materialise)

– NobelGuide™ (NobelBiocare)

• Sometimes give a false impression of

safety

• Blind surgery if performed flapless

Surgery performed with a drill Guide

Postoperative imaging

Here we have an obvious problem !Apparent correct position of

both implants

Preoperative and postoperative matching

Frontal view Occlusal view

Distal displacement of the tip of the right

Zygomatic implant

Orange= planned position; Yellow = placed position

Top view Left lateral view

Orange= planned position; Yellow = placed position

Cranial displacement of the tip of the left

implant with pterygoid anchorage

>15 mm

>10 mm

Navigation technique

• Is more interactive than drill guide surgery

• Peroperative finding sometimes

≠radiological findings

• Seems to be the most flexible approach

To Guide or not to Guide?

• Usefulness of a conventional drill guide in

zygoma implants seems rather limited due

to very large exit points deviations

• Navigation technique seems to be very

promising

• Mental navigation depends on the

surgeons skills and ability to visualise in

3D

Overview

• Indications





• Stella

• Extramaxillary

• Quad zygoma

• Zygoma and pterygoid


Techniques

Intrasinusal

4 standard implants frontal, 2 zygoma dorsal

Intrasinusal

4 standard implants frontal, 2 zygoma dorsal

Simplant SurgiGuide™ Safe System™ prototype (2001)

Intrasinusal

Intrasinusal

Stella

Typical position for a “Stella”

Extramaxillary

Buccal coverage with a Titanium mesh

Pterygoid implant

Extramaxillary Zygoma implant

Extramaxillary

Extramaxillary

Quad Zygoma

Div D Div D Div D

Quad Zygoma

16 13 11 21 23 26

Hgt 6.00 10.08 7.78 8.53 9.79 -

Th 1.82 3.77 5.37 2.52 2.81 -

Quad Zygoma

Quad Zygoma

Bone supported zygoma drill guide

Quad Zygoma

4x Extra maxillary Zygoma implants

Quad Zygoma

Coverage with Isotis™

Quad Zygoma

Postoperative view

Quad Zygoma

Pterygoid implants

Skull base implants

1997

Skull base implants

1999

Skull base implants

2000

Finally all implants get lost …

Skull base implants

Skull base implants

12/09/2005: Follow up

Skull base implants

18/05/2010: Follow up 8 jaar

Skull base implants

18/05/2010: Follow up 8 jaar

Look at the extreme vertical height of the prosthesis

Skull base implants

Where to find additional information?

• Zygoma Course 10 and 11/12 in Brussels

• www.linkedIn.com

http://www.linkedin.com/

Two day Zygoma course in

Brussels on 10 and 11/12/2010

Where to find additional information?

• www.linkedIn.com Zygoma implant group

http://www.linkedin.com/

Conclusion

• Long implants can offer a solution for

totally „hopeless‟ cases

• The technique requires advanced surgical

skills and top notch prosthetic therapy

• The preoperative and postoperative

trajectory must be closely monitored in

order to evaluate the long term results of

this technique

Long (zygomatic) Implants as a last resort

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