TREATMENT OF FRACTURES OF THE ATROPHIC MANDIBLE IN THE ELDERLY

Three-Dimensional Printing Bioceramic Scaffolds Using Direct-Ink-Writing for Craniomaxillofacial Bone Regeneration

Defects characterized as large osseous voids in bone, in certain circumstances, are difficult to treat, requiring extensive treatments which lead to an increased financial burden, pain, and prolonged hospital stays. Grafts exist to aid in bone tissue regeneration (BTR), among which ceramic-based grafts have become increasingly popular due to their biocompatibility and resorbability. BTR using bioceramic materials such as β-tricalcium phosphate has seen tremendous progress and has been extensively used in the fabrication of biomimetic scaffolds through the three-dimensional printing (3DP) workflow. 3DP has hence revolutionized BTR by offering unparalleled potential for the creation of complex, patient, and anatomic location-specific structures. More importantly, it has enabled the production of biomimetic scaffolds with porous structures that mimic the natural extracellular matrix while allowing for cell growth-a critical factor in determining the overall success of the BTR modality. While the concept of 3DP bioceramic bone tissue scaffolds for human applications is nascent, numerous studies have highlighted its potential in restoring both form and function of critically sized defects in a wide variety of translational models. In this review, we summarize these recent advancements and present a review of the engineering principles and methodologies that are vital for using 3DP technology for craniomaxillofacial reconstructive applications. Moreover, we highlight future advances in the field of dynamic 3D printed constructs via shape-memory effect, and comment on pharmacological manipulation and bioactive molecules required to treat a wider range of boney defects.

Treatment of atrophic mandibular fractures with the pencilboneplate: report of 2 cases

The incidence of fractures of the atrophic edentulous mandible is still low, even with the increasing life expectancy. The reduced blood supply of the sclerotic bone, the diminished contact area between bone fragments and the patient's systemic condition makes the treatment of those fractures a challenge for any professional. Treatment of atrophic mandibular fractures by means of miniplate osteosynthesis has not been the preferred method of fixation by many authors. Yet, many surgeons have applied this type of fixation for the atrophied jaw sections. This paper reports 2 cases of fractured atrophic mandibles treated with the pencilboneplate, a monocortical 2.0 mm titanium, 8 or 10-hole hardware with reinforcement on its middle portion, highlighting important considerations of its use. The pencilboneplate appears to be a valuable option for the treatment of atrophic mandibular fractures, especially by an intra-oral approach, and warrants further biomechanical and clinical studies.

Fixation of atrophic edentulous mandible fractures by bone plating at the inferior border

PURPOSE

No consensus has been reached regarding the best treatment for repair of fractures of the severely atrophic mandible (<10 mm vertical height). The most complete Cochrane review of the published data could not substantiate a single best practice recommendation for treating these fractures. The present study reports the results of such treatment by placing miniplates at the inferior border of the mandible of 23 fractures of the mandibular body in 16 patients.

MATERIALS AND METHODS

This was a consecutive case series during a 30-year period performed by a single surgeon at several practice locations using the technique of extraoral plating at the inferior border. All patients were prospectively monitored clinically and radiographically for achievement of bony union and for complications of sensory disturbances of the lower lip, delayed healing, and hardware removal. The mean observation time was 23.1 months (range 1 to 60), with only 2 cases observed for less than 6 months.

RESULTS

All the patients achieved clinical union of their fractures. Two cases of fibrous union did not reach ossification until 5 months after surgery. The hardware removal rate was 13.6%, and the infection/prolonged inflammation rate was 13.6%. There was 1 case of malunion. Those patients who had dentures were able to return to denture wearing postoperatively.

CONCLUSIONS

Miniplate fixation of fractures of the severely atrophic mandible at the inferior border is safe and effective.

Macroplate fixation of fractures of the edentulous atrophic mandible: immediate function and masticatory rehabilitation

The present study aimed at evaluating the treatment outcome of fractures of the edentulous atrophic mandible by means of an extraoral approach using open reduction and internal fixation with macroplates. Eighteen patients with 21 fractures of the atrophic mandible, who had been treated between 1997 and 2006, were retrospectively analysed. Mandible height was categorised according to the Luhr classification and the patients' general health (The American Society of Anesthesiologists (ASA) classification). Three types of titanium macroplates were used. Demographic data, treatment outcomes and the pre- and postoperative ability to wear mandible dentures were evaluated. The study population consisted of five men and 13 women with a median age of 78 years. The mean follow-up duration was 28 months. The most common cause of fractures was accidental falls (50%); the mandible was affected in 77.8%. Three fractures occurred in class I (bone height 15-20 mm), seven in class II (10-15 mm), and 11 in class III atrophy (<10 mm). According to the ASA classification, the collective showed a mean value of 3. An overall complication rate of 16.7% was noted, consisting of two minor and one major complication that required a second intervention. Five patients needed removal of the osteosynthesis material for prosthetic reasons. Only 50% of the patients were able to wear their dentures before surgery, and all but one were able to wear their prosthesis postoperatively. Treatment of atrophic mandible fractures with macroplates by means of an extraoral approach showed good results and a low complication rate. This procedure allows elderly patients to instantly load the mandible in the means of prosthetic and masticatory rehabilitation, preventing the necessity for second interventions.

A Biomechanical Comparison of 2 Techniques for Reconstructing Atrophic Edentulous Mandible Fractures

OBJECTIVES

The purpose of this investigation was to evaluate and compare the biomechanical behavior of 2 techniques for the reconstruction of atrophic edentulous mandible fractures.

MATERIALS AND METHODS

Thirty polyurethane atrophic edentulous mandible replicas (Sawbones, Vashon Island, WA) were used in this investigation (10 controls, 10 replicas of 2 different fixation techniques). The first reconstruction technique was a traditional titanium locking reconstruction plate affixed to the lateral border (buccal surface) of the mandible. The second reconstruction technique used the same type of plate, but placed it on the inferior border of the mandible. Both constructs were subjected to vertical loading at the symphysis and torsional loading at the body regions of the mandible replicas by an Instron 1331 (Instron, Canton, MA) servohydraulic mechanical testing unit. Mechanical deformation data within a 0-900 N range were recorded. Maximum load, displacement at maximum load, and stiffness were determined. Means and standard deviations were derived and compared for statistical significance using a Fisher's Protected Least Significant Differences Test with a confidence level of 95% (P < .05). Second- and third-order polynomial best-fit curves were also created for each group to further evaluate the mechanical behavior.

RESULTS

For symphysis loading, statistically significant differences were noted between the control group and both of the plating techniques for displacement at maximum load. However, no differences were noted between the experimental groups for displacement at maximum load, stiffness, or maximum load. For body loading, statistically significant differences were noted between the control group and the inferior border plating group for displacement at maximum load. However, no differences were noted between the experimental groups for displacement at maximum load, stiffness, or maximum load.

CONCLUSION

During this bench top investigation, there were no significant differences noted in mechanical behavior between the 2 specific experimental groups for any of the conditions measured. When placed in the context of functional parameters, both of the plating techniques met or exceeded the requirements for loading.