Three-Dimensional Planning of Alveolar Ridge Distraction by Means of Distraction Implants

Novel multi-axial alveolar distractor - Part I: Design, manufacture, and mechanical/functional tests

PURPOSE

This study developed a novel multi-axial alveolar distractor and evaluated its safety and effectiveness by performing various mechanical tests and finite element (FE) analysis.

MATERIALS AND METHODS

A ball-and-socket joint with a high degree of freedom was proposed as the design concept to make the distractor produce a cone trajectory motion range of up to 60° with respect to the transport screw (central axis). This device was manufactured with Ti6Al4V alloy. Mechanical functional tests included four-point bending resistance testing of the base bone plate, pull-out testing of the multi-axial alveolar distractor, welding strength testing between the base bone plate and ball-and-socket joint mechanism, and torque strength testing of the ball-and-socket joint. These tests were performed to ensure the effectiveness and safety of the multi-axial alveolar distractor. The base bone plate FE analysis of four-point bending resistance and pull-out testing of the multi-axial alveolar distractor were performed to confirm the results obtained from the experimental testing.

RESULTS

The bending strength for the four-point bending test and the maximum force for pull-out testing were 530.88 N mm and 716.33 N, respectively. Substantial equivalence FE simulations also found that large deformations for four-point bending and pull-out testing were smaller than those for the commercial alveolar distractor, indicating that our new distractor is as safe and effective as the commercially available device. The maximum debonding torque resistance for ball-and-socket joint mechanism welding strength was 3481.1 N mm, meaning it is unable to fall off during a surgical operation. No damage was found at the welding edge. The maximum average resistance force in the ball-and-socket joint was 30.26 N without rotation, allowing it to resist distraction forces during bone regeneration - an important safety consideration.

CONCLUSION

The alveolar distractor designed using a ball-and-socket joint concept can achieve multi-axial distraction with various angle adjustments in 3D space. Thorough mechanical/functional tests confirm the effectiveness and safety of our new multi-axial alveolar distractor.

Reconstruction and rehabilitation of severe mandibular atrophy using distraction osteogenesis technique: a case report

PURPOSE

The purpose of this article is to describe a rehabilitation technique for patients with severe anterior atrophy using a combination of distraction osteogenesis and implants to support fixed or removable prostheses.

MATERIALS AND METHODS

The surgical technique involves the use of an extraosseous distraction device followed by more than 14 mm of distraction of the mandibular symphysis.

RESULTS

The patient was successfully treated by the application of 4 implants in the region of the mandibular symphysis, stabilized by an Ackerman bar, and a removable prosthesis.

CONCLUSION

Osseous distraction techniques, when possible, are preferable to block bone grafting techniques because they present considerable advantages for patients and surgeons. The combination of distraction and implant placement can rehabilitate patients with severe defects.

Combined orthodontic temporary anchorage devices and surgical management of the alveolar ridge augmentation using distraction osteogenesis

PURPOSE

Distraction osteogenesis is used to increase the vertical and transverse bone volume of the alveolar ridge and requires 3-dimensional vector controls. Temporary anchorage devices (TADs) may be inserted into the transported segment, enabling distraction vector control by exerting orthodontic force. The authors' aim was to describe a combined orthodontic surgical technique involving vertical alveolar distraction using TADs.

MATERIALS AND METHODS

Four patients who presented with extensive anterior alveolar ridge bone loss combined with the incisors and canines underwent treatment according to a combined surgical orthodontic protocol, including presurgical orthodontic preparation and a preimplantation surgical augmentation stage involving vertical distractor insertion. During the active vertical alveolar distraction process, 3 TADs were inserted. Intraoral orthodontic elastics were attached to the main orthodontic archwire exerting multidirectional forces to control the vertical distraction vector. After 4 to 5 months of vector controlling and active bone molding, the TADs were removed.

RESULTS

Anterior alveolar ridge augmentation using distraction osteogenesis was achieved. The application of TADs for better anterior segment curvature enabled dental implant insertion, ideal positioning, and restoration.

CONCLUSIONS

A combined surgical orthodontic management protocol involving vertical alveolar distraction osteogenesis for augmentation purposes using TADs enables improved alveolar ridge volume and architecture for the preimplantation stage.

3D vector control during alveolar ridge augmentation using distraction osteogenesis and temporary anchorage devices: a new technique

This report describes a combined orthodontic surgical technique involving vertical alveolar distraction using temporary anchorage devices (TADs) in cases of massive alveolar ridge bone and teeth loss. A combined surgical orthodontic protocol included presurgical orthodontic preparation and a preimplantation surgical augmentation stage for insertion of a vertical distractor. During the active vertical alveolar distraction process TADs were inserted. Intraoral orthodontic elastics were attached to the main orthodontic archwire exerting multidirectional forces to control the vertical distraction vector. After 3 months of vector controlling and active bone moulding, the TADs were removed. Anterior alveolar ridge augmentation using distraction osteogenesis was achieved. The application of TADs for better anterior segment curvature enabled dental implant insertion, better positioning and restoration. A combined surgical orthodontic management protocol involving vertical alveolar distraction osteogenesis for augmentation purposes is an efficient treatment method to improve alveolar ridge volume for the preimplantation stage.

Osteogenic alveolar distraction: A review of the literature

OBJECTIVE

Alveolar distraction is a relatively novel procedure by which alveolar bone and underlying mucosa are regenerated. The low predictability of other vertical or horizontal bone regeneration methods has increased interest in this promising technique. This article was designed to review published clinical and experimental results on alveolar distraction, including basic research in other disciplines (maxillofacial and orthopedic distraction) related to or with influence on alveolar distraction.

STUDY DESIGN

A review of the international literature was performed to summarize results of clinical and experimental studies on alveolar distraction and on distraction at other anatomical sites that contribute important findings on tissue biology, molecular mechanisms, and other factors that influence and participate in the alveolar distraction process.

RESULTS

Research into alveolar distraction has addressed the latency phase, distraction phase, and consolidation phase, yielding highly variable results. Little experimental research has been carried out on this procedure, and most publications are clinical studies with a short follow-up period. Published studies have reported a high rate of complications, attributable to our current lack of understanding of the process.

CONCLUSIONS

Definitive conclusions on alveolar distraction are hampered by the lack of clinical and experimental studies to date. Greater knowledge of the factors that influence the distraction process will lead to a more predictable and efficacious distraction technique and a better distractor design.