Long implants: The last resort
Luc vrielinck, Oral and MF Surgeon, Genk, Belgium Luc@Vrielinck.be
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 ↓ Width
A
B
↓ Height
B-w
C-w
C-h
D
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
What is terminal bone atrophy? • Classification of bone atrophy • How do we diagnose terminal bone atrophy? • Overview af treatment modalities with 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
21
22
23
24
12
11
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
What is terminal bone atrophy? • Classification of bone atrophy • How do we diagnose terminal bone atrophy? • Overview af treatment modalities with advancing atrophy
Typical treatment strategies with increasing bone atrophy
A
B
B-w
C-w
C-h
D
Zygoma Short Sinus lift All-on-4 Standard implants Div A
Div B
Div C
Div D
Overview • Indications • Techniques for long implants • Clinical examples
Techniques for long implants • • • • • •
Intrasinusal (Brånemark) Stella Extramaxillary Quad zygoma Pterygoid implants Skullbase implants
Intrasinusal zygoma
Techniques for long implants • • • • • •
Intrasinusal (Bränemark) Stella Extramaxillary Quad zygoma Pterygoid implants Skullbase implants
Anterior slot technique
Techniques for long implants • • • • • •
Intrasinusal (Bränemark) Stella Extramaxillary Quad zygoma Pterygoid implants Skullbase implants
Extramaxillary
Techniques for long implants • • • • • •
Intrasinusal (Bränemark) Stella Extramaxillary Quad zygoma Pterygoid implants Skullbase implants
Quad zygoma
Techniques for long implants • • • • • •
Intrasinusal (Bränemark) Stella Extramaxillary Quad zygoma Pterygoid implants Skullbase implants
Pterygoid / Sphenoid
Techniques for long implants • • • • • •
Intrasinusal (Bränemark) Stella Extramaxillary Quad zygoma Pterygoid implants Skullbase implants
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
To guide or not to guide? • Mental navigation • Drill guide surgery • Navigation technique
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
Apparent correct position of both implants
Here we have an obvious problem !
Postoperative imaging
Orange= planned position; Yellow = placed position Frontal view
Occlusal view
Distal displacement of the tip of the right Zygomatic implant Preoperative and postoperative matching
Orange= planned position; Yellow = placed position
Top view
Left lateral view >15 mm
>10 mm
Cranial displacement of the tip of the left implant with pterygoid anchorage
To guide or not to guide? • Mental navigation • Drill guide surgery • Navigation technique
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 • Techniques for long implants • Clinical examples
Techniques for long implants • • • • • •
Intrasinusal (Bränemark) Stella Extramaxillary Quad zygoma Zygoma and pterygoid Skullbase implants
Techniques
Intrasinusal
Intrasinusal
4 standard implants frontal, 2 zygoma dorsal
Intrasinusal
Simplant SurgiGuide™ Safe System™ prototype (2001) 4 standard implants frontal, 2 zygoma dorsal
Intrasinusal
Simplant SurgiGuide™ Safe System™ prototype (2001) 4 standard implants frontal, 2 zygoma dorsal
Intrasinusal
Simplant SurgiGuide™ Safe System™ prototype (2001) 4 standard implants frontal, 2 zygoma dorsal
Intrasinusal
Stella
Stella
Stella
Typical position for a “Stella”
Extramaxillary
Extramaxillary
Extramaxillary
Pterygoid implant Extramaxillary Zygoma implant Buccal coverage with a Titanium mesh
Extramaxillary
Extramaxillary
Quad Zygoma
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
Quad Zygoma
Bone supported zygoma drill guide
Quad Zygoma
4x Extra maxillary Zygoma implants
Quad Zygoma
Coverage with Isotis™
Quad Zygoma
Postoperative view
Pterygoid implants
Pterygoid implants
Pterygoid implants
Pterygoid implants
Pterygoid implants
Pterygoid implants
Pterygoid implants
Pterygoid implants
Skull base implants
Skull base implants
1997
Skull base implants
1999
Skull base implants
Finally all implants get lost ‌ 2000
Skull base implants
Skull base implants
12/09/2005: Follow up
Skull base implants
12/09/2005: Follow up
Skull base implants
12/09/2005: Follow up
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
Skull base implants
18/05/2010: Follow up 8 jaar
Skull base implants
Look at the extreme vertical height of the prosthesis 18/05/2010: Follow up 8 jaar
Where to find additional information? • Zygoma Course 10 and 11/12 in Brussels • 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
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