Rehabilitation of anterior maxilla  with limited spaces after traumatic injury

CONTENTS

Introduction

A 42-year-old female patient was referred to my practice after a bicycle accident. Her teeth 12 and 11 were displaced out of the sockets and the crown of 21 was fractured.

Fig. 1 Panorama radiography before treatment shows the exarticulated 12 and 11, and fractured crown in 21 (FDI system) .

Treatment planning

After the accident, the extent and severity of trauma – which may compromise the healing of bone and soft tissues – should not be underestimated. I always wait at least 1 year in the post-traumatic zone before starting the implant therapy.

In this case, the patient received a Maryland bridge for the healing period, and we started the implant treatment 1.5 years after the accident.

Fig. 2 Intraoral views before treatment show the hard and soft tissue loss and the narrow space which is challenging for implant placement

The patient had a medium to high smile line, a deep bite and limited horizontal space due to maxillary tooth crowding with the palatal position of both lateral incisors. With all the esthetic challenges, digital planning with DTX Studio™ was inevitable. 

We transferred the CBCT data to the software and started to work with technicians for intraoral scanning and the digital diagnostic wax-up. This was done in order to investigate if it was possible to achieve a good functional and esthetic result without hard or soft tissue reconstruction, to allow for minimally invasive treatment.

Fig. 3 CBCT data exported to DTX Studio™, intraoral scanning and digital diagnostic wax-up.

Note the shape of soft tissue in the marked area in Fig. 3 C where I was most concerned about. We built the computer-aided manufactured dummy (Fig. 4) based on diagnostic wax-up and did the try-in in the patient.

Fig. 4 CAM dummy based on digital diagnostic wax-up and patient try-in

In the implant position planning, we could immediately see the limited space between the canine and the left central and the volume of the bone which dictated placing the implants quite deep. Such challenges increase the risk of interference between abutment and dentition and make the use of angulated screw channel abutments absolutely necessary.

Fig. 5 The following of the contour from the implant to the abutment, and to the diagnostic wax-up, with the Zr NobelProcera ASC abutment in planning.

On the other hand, when using the Titanium NobelProcera ASC abutment which can be custom-made for implants with limited space, we could see a good match and following of the contour from the implant to the abutment, and to the diagnostic wax-up. That could not be achieved without the angulated screw channel abutment.

“Titanium NobelProcera ASC abutment can be custom-made for implant therapy in challenging esthetic zones with limited space.” Stefan Lundgren

Surgical procedure

After marking the implant location using NobelGuide®, a small horizontal incision palatal to the marked area was made, and only the buccal mucosa was pushed buccally, allowing to use a soft tissue punch for the palatal mucosa, thus giving special attention to keeping the buccal soft tissue as thick and intact as possible. 


The NobelGuide® was then placed and stabilized with the anchor pin, and 2 NobelParallel TiUltra implants with narrow platforms were placed following the manufacturer's instructions.

Fig. 6 Site preparation and implant placement. X-ray shows the implant position and seating of healing abutments.

Prosthetic procedure and treatment outcomes

After implant insertion, we used the Maryland bridge for another 5 weeks before delivering the temporary crowns and starting to modulate the soft tissue – gradually increasing or correcting the diameter of the temporary crown until we can design the final crown. In my experience, waiting at least 3 months between temporary and final crown delivery is crucial for lasting esthetic outcomes.

Fig. 7 Delivery of provisional crown 5 weeks after implant insertion and starting to modulate the soft tissue by adjusting the temporary crown before delivery of final prosthesis.

Fig. 8 NobelProcera® Titanium ASC abutment, and final prostheses.

Fig. 9 See the final prosthesis and soft tissue outcome at delivery of the permanent crowns. The screw access holes are located on the palatal aspect for a cement-free esthetic solution. 

Key to success

As Mark Twain said, “Good decisions come from experience, while experience comes from bad decisions.” Tissue regeneration is one of my main research interests as a surgeon and scientist. I have done numerous reconstructions in cancer, trauma and other compromised patients. But I have also done a lot of unnecessary reconstructions in my early days, when a much less invasive or complex treatment could be possible. When lecturing today, especially for younger clinicians, I advocate digital planning, to identify first the real challenges and limitations of each case – instead of immediately jumping on more complex and technique-dependent treatments. Freehand surgery without digital planning is very similar to driving in the rain without the aid of wipers. DTX gives clinicians the possibility to try different prosthetic components and verify how far they can go before considering any augmentations – which often come with certain risks.

We should, in every case, ask ourselves, “What is needed in this case?” and choose the least invasive solution, in concern of the patient. This also means we still have the more-invasive treatment option if later needed.

About the author

Prof. Stefan Lundgren is a senior professor and former chairman at the Department of Oral Maxillofacial Surgery - Umeå University in Sweden. In addition to being an internationally renowned lecturer, author of more than 70 publications in oral maxillofacial treatments, Prof. Lundgren also performs implant surgery in private practice with a focus on mentorship for the young dentists in the clinic.