Age-related new bone formation following the use of cancellous bone-block allografts for reconstruction of atrophic alveolar ridges

Volumetric Changes of a Customized Allogeneic Bone Block Measured by Two Image Matching Tools: Introduction of a Novel Assessment Technique for Graft Resorption

Objective

The purpose of this case report was to present a method for the assessment of volumetric changes of bone blocks during healing and demonstrate its practicability by analysing the resorption of a pre-shaped allogeneic bone block used for the reconstruction of a complex maxillary defect.

Materials and methods

CBCT-scans of a 19-year-old male treated with an allogeneic bone block were recorded pre-OP, post-OP, and following six months of healing. Graft shrinkage was assessed via two image matching tools, namely coDiagnostiX® and Slicer. A biopsy specimen was harvested along the implant canal at the time of implantation.

Results

The osseous defect was successfully restored and advanced graft remodelling was found upon re-entry as confirmed by the histomorphometric and histologic analysis. The initial volumes of the graft determined via coDiagnostiX® and Slicer were 0.373 mL and 0.370 mL., respectively, while graft resorption after six months of healing was 0.011 mL (3.00%) and 0.016 mL (4.33%).

Conclusions

The avoidance of bone harvesting and reduction of invasiveness display an important issue in dentoalveolar restorations. However, before grafting materials can be considered a safe alternative, understanding their clinical performance, especially resorption stability, is pivotal. The present case report demonstrates a limited resorption of the allogeneic bone block and further emphasizes the practicability of determining bone resorption by the here introduced method. As our investigation comprises solely one subject, the results should be considered with care and substantiated by further studies.

The Effect of Age on Fracture Healing Time in Metacarpal Fractures

Background: Older patients are treated for fracture with increasing frequency. Although studies on animals suggest that older mice and rats heal fractures more slowly, the clinical implications remain unclear. A better understanding of differences in healing with age can help customize fracture treatment. Our purpose was to retrospectively evaluate metacarpal fractures for healing time looking specifically at age-related differences. Methods: A retrospective review of patients treated for metacarpal fractures was conducted. Patients with incomplete charts or inadequate follow-up were excluded. One hundred ninety-eight charts were analyzed. Demographic and other patient factors were documented. Fracture characteristics and treatment type were documented. Fracture healing was determined clinically. Plain radiographs and examination were used in decision making. Results: Age was not associated with fracture healing time as a continuous variable (P = .09). Patients above 75 years were not associated with increased healing time (P = .58). Fracture characteristics were related to healing time: minimally displaced and comminuted fractures healed faster than oblique fractures, spiral fractures, or transverse fractures (P = .048). Patients undergoing surgery healed faster than those without surgery (P = .046). Renal failure negatively affected fracture healing time (P = .03). Diabetes, hypothyroidism, and gender were not associated with healing time. Complications were not associated with age or other patient or fracture-related factors. Conclusions: Age does not affect clinical fracture healing time in adult. Therefore, older patients do not require disparate treatment. Other fracture-related factors and considerations such as functional demand and support systems might influence treatment decisions in fracture care.

Assessment of clinical outcomes and histomorphometric findings in alveolar ridge augmentation procedures with allogeneic bone block grafts: A systematic review and meta-analysis

BACKGROUND

This systematic literature review aimed to evaluate the efficacy of allogeneic bone blocks for ridge augmentation by assessing block survival rates and subsequent implant survival, including post-surgical complications and histomorphometric analysis.

MATERIAL AND METHODS

An electronic and manual search among references, was conducted up to April 2019 by two independent authors. Inclusion criteria were: human clinical trials in which the outcomes of allogeneic bone block grafts were evaluated by means of their survival rates and subsequent implant success rates.

RESULTS

Seven articles fulfilled the inclusion criteria and were analyzed. A total of 323 allogeneic block grafts were monitored for a minimum of 12 months follow-up after surgery, of which thirteen (4.02%) failed. Regarding the cumulative implant survival rate, the weighted mean was 97.36%, computed from 501 implants. Histologic and histomorphometric analysis showed that allogeneic block grafts presented some clinical and microstructural differences in comparison with autologous block grafts.

CONCLUSIONS

Atrophic alveolar crest reconstruction with allogeneic bone block grafts would appear a feasible alternative to autologous bone block grafts, obtaining a low block graft failure rate, similar implant survival rate and fewer postoperative complications. Further investigations generating long term data are needed to confirm these findings.