Ramus Frame Implant Revisited

Introduction

A common problem with long-term edentulism is advanced osseous atrophy, especially in the mandible. Removable complete dentures are likely to be unstable and lack sufficient retention for adequate function.^1–4 The mandibular bone can be very thin and unable to accept endosseous implants for prosthetic support^1–4 (Figures 1 and 2). As the mandible resorbs, the osseous ridge crest moves medially and apically. The facial and lingual cortices approach each other. The symphysis may become prominent, and the genial tubercles can be at or above the ridge crest. Vertical dimension of occlusion can decrease, producing facial and functional detriments. In jaw overclosure, the position of the mandible can move closer to the maxilla and can lead to angular cheilitis, aesthetic compromises and decreased function.⁵

Figures 1–6

Figure 1. The atrophic mandible may not adequately support or retain a mandibular complete denture, so retention and support can be provided by a ramus frame implant. Figure 2. Panoramic radiograph of the atrophic mandible demonstrates inadequate bone for screw-type dental implants but adequate bone at the symphysis and the ramus for placement of a ramus frame implant. Figure 3. Initial incision bisecting attached gingiva with releasing incisions. Figure 4. Anterior osteotomy prepared with highspeed surgical drill. Figure 5. The anterior osteotomy is completed. Figure 6. Anterior foot analog is tried-in and the osteotomy is adjusted to accept the analog.

[Image Omitted. See PDF.]

With the mandibular osseous crest now lingual to proper tooth position, prosthetic fabrication needs to be designed and engineered for esthetic and masticatory function. The remaining bone volume and location may be inadequate to accept cylindrical endosseous implants.⁶ Supportive cylindrical dental implants may not be placed in appropriate positions for proper prosthetic design. Neurovascular transposition or vertical augmentation of the atrophic ridge can be done, but these have a significant potential for serious complications and costs.

When the maxilla is restored with a removable complete denture, the opposing atrophic mandible will have diminished functional loading and decreased off axial loading that would complicate prosthetic rehabilitation.^1–4 A maxilla with a fixed prosthesis or natural tooth dentition may place a significant dynamic loading on a mandibular complete denture, and that would require a fixed retentive modality.

The...