Vertical ridge augmentation using guided bone regeneration technique

The following clinical report is a part of vertical ridge augmentation (VRA) case series using different techniques by Drs Chang I C Teoh and Kevin Ng. In this paper, they addressed a vertical bone defect on an area with high aesthetic demands by employing guided bone regeneration (GBR) technique.

INTRODUCTION

Dental implant has been established to be a predictable treatment option for partially edentulous patients1. However, one of the pre-requisite conditions for successful implant treatment is to have a sufficient bone volume for optimal 3D implant placement2.

Many clinical situations present inadequate bone volume and require bone augmentation in varying degree, with or without simultaneous implant placement. To many clinicians, ridge augmentation of medium to large vertical defects is often considered to be challenging and difficult.

Several techniques3,4 have been described for augmenting vertical ridge defects including guided bone regeneration (GBR) which uses a combination of membrane barriers and different grafting materials; autogenous bone block grafts; autogenous particulate grafts; 3D Split bone block; distraction osteogenesis; 3D CAD/CAM titanium scaffold with different types of biomaterials; or a combination of these.

DISCUSSION

Bone dimensional changes after tooth loss is well documented5,6. The final ridge morphology is often the end result of a combination of predisposing factors subjected to the area affected.

For instance, bone destruction caused by advanced periodontitis, multiple tooth loss, peri-implantitis, trauma, long-term denture wearing, unfavourable loading, or a combination of these factors may result in advanced bone loss and severe ridge defect in either horizontal, vertical, or combination dimension.

There are a number of classifications of bony defect described in the literature. Cologne classification of alveolar ridge defects (CCARD)9 offers a more comprehensive description of the types of ridge defect presented to the clinicians and their management.

In general, vertical ridge augmentation (VRA) is more demanding in soft tissue management because of the need to stabilise the augmentation material as compared to horizontal ridge augmentation (HRA).

The inclusion of autogenous bone materials in VRA is often recommended to improve the outcome. However, the complication rate10 associated with this procedure is considerably higher than HRA.

VRA is challenging primarily due to the difficulty to stabilise the bone graft material without the support of the bony wall, and the angiogenesis has to reach a distance from the native bony bed.

Additionally, an absolute tension-free soft tissue advancement is essential to achieve a primary closure and prevention of wound dehiscence during the entire period of healing11.

The following clinical report is a part of vertical ridge augmentation (VRA) case series using different techniques. Guided bone regeneration (GBR) was employed in this case.

CASE PRESENTATION

This is a case of a 30-year-old Afro-Caribbean female who used to work as a school teacher. She was generally in good health upon consultation with no significant health issues.

In 2017, she experienced mobility on her tooth 21. Her dental history revealed that her teeth 21 and 22 suffered from a traumatic injury when she was a teenager.

Tooth 21 was avulsed but was reimplanted successfully at the time of injury by her dentist. The dentist also restored the fractured tooth 22 with a partial veneer restoration. Both teeth were uneventful after the treatment.

However, tooth 21 started to become increasingly mobile over the last few years. Periapical radiograph showed that the tooth has advanced bone loss with poor prognosis (Fig. 1).

Patient would like to have a fixed implant treatment option to replace the failing tooth. After careful discussion, a treatment plan was formulated.

To meet the highly-aesthetic demands of the anterior region, a stage approach was employed to rehabilitate the area:

Stage 1: Removal of tooth 21 and temporary replacement with metal acrylic adhesive bridge. Reassessment after three months of healing.

Stage 2: VRA with GBR technique using titanium reinforced cytoplast d-PTFE membrane plus Emdogain (Enamel Matrix Derivatives) treatment.

Stage 3: Implant placement eight months after VRA. Soft tissue augmentation plus provisional and final crown on implant.

Clinical presentation after tooth 21 extraction:

  • Medium to high lip line
  • Thin biotype
  • Medium vertical bone defect
  • Papilla loss on the mesial of tooth 22
  • Reduced interproximal bone peak mesial to tooth 22
  • Class I incisal relationship
  • Tooth 22 is restored with a partial porcelain veneer
  • Ridge defect – Cologne classification: V.2.i – vertical defect of 4-8mm, inside the ridge contour

About the authors

Dr Chang I C Teoh spent over 10 years of his career in England as an implantologist. He has particular interest in ridge regeneration and immediate-loading implants and is now in a private practice in Hong Kong.

Dr Kevin Ng is a visiting professor at GongZhou Medical University, China, and runs a private practice in Hongkong.

Continue reading here. Published in Dental Asia May June 2021 issue.