Sagittal split osteotomy fixed with biodegradable, self-reinforced poly-L-lactide screws. A pilot study in sheep

Area of Science:

• Biomaterials Science
• Oral and Maxillofacial Surgery
• Orthopedic Surgery

Background:

• Mandibular fractures and osteotomies require stable fixation for healing.
• Traditional fixation methods may have limitations.
• Biodegradable materials offer potential advantages in bone fixation.

Purpose of the Study:

• To evaluate the efficacy of self-reinforced poly-L-lactide (SR-PLLA) screws for rigid fixation of bilateral mandibular sagittal split osteotomies (SSO).
• To assess the biomechanical strength and histological healing of SR-PLLA fixed SSO in a sheep model.

Main Methods:

• Six sheep underwent bilateral SSO fixed with SR-PLLA screws, without intermaxillary fixation.
• Postoperative follow-up was 16 weeks.
• Evaluations included photography, radiography, biomechanical bending strength tests, histological analysis, and microradiography.

Main Results:

• SR-PLLA screws demonstrated sufficient strength for rigid fixation of SSO.
• The bending force required to fracture the operated mandible exceeded that of an unoperated mandible.
• Histological and microradiographic studies confirmed uneventful osteotomy healing in all subjects.

Conclusions:

• SR-PLLA screws provide effective rigid fixation for mandibular SSO.
• The material supports robust bone healing, comparable to or exceeding native bone strength.
• This technique is a viable option for managing mandibular fractures and osteotomies in humans.