Platelet-Rich Plasma for Bone Healing in Maxillary and Mandibular Fractures

Background and rationale:

Fractures of the maxilla and mandible are common in facial trauma and require rapid, reliable bone healing to restore chewing function and facial appearance. Conventional management with rigid internal fixation is effective, but delayed union and incomplete bone regeneration still occur. Autologous platelet-rich plasma (PRP) contains high concentrations of growth factors, including platelet-derived growth factor (PDGF), transforming growth factor-beta (TGF-beta), and vascular endothelial growth factor (VEGF), which promote osteogenesis and angiogenesis. Because it is prepared from the patient's own blood, PRP is biocompatible, low-cost, and carries minimal risk of immune reaction. Randomized trials have reported higher radiographic bone density and faster healing with PRP in mandibular fractures; however, a recent systematic review and meta-analysis found that available trials are limited almost entirely to the mandible and that pooled estimates are heterogeneous. Evidence on PRP in maxillary trauma is scarce, and no randomized trial has assessed PRP in both maxillary and mandibular fractures within the same cohort using a standardized CBCT-based protocol.

Study design and setting:

Single-centre, parallel-group, two-arm randomized controlled trial at the Maxillofacial Center, CMH Lahore Medical College and Institute of Dentistry, Lahore, Pakistan.

Randomization and masking:

Eligible patients will be allocated in a 1:1 ratio using a computer-generated randomization list, stratified by fracture site (maxilla or mandible). Allocation will be concealed in sequentially numbered, sealed, opaque envelopes opened in the operating theatre. The investigator measuring bone density on CBCT will be blinded to group allocation.

PRP preparation:

Twelve ml of venous blood will be drawn into sodium citrate tubes and processed at room temperature by double centrifugation: 1200 rpm for 20 minutes to separate plasma, then 2000 rpm for 15 minutes to concentrate platelets. The platelet-rich fraction will be retained and platelet-poor plasma discarded. Platelet count and smear will be performed to confirm concentration and morphology. Immediately before use, PRP will be activated with calcium chloride and bovine thrombin to form a platelet gel.

Surgical procedure:

All operations will be performed under general anaesthesia by the same surgical team. The fracture will be exposed through a vestibular incision, reduced manually, and fixed with two titanium miniplates and screws. In the PRP group, activated PRP gel will be applied along the fracture line before closure; the control group will receive identical fixation without PRP. Wounds will be closed with Vicryl sutures. All patients will receive antibiotics and anti-inflammatory medication for one week and intermittent cold packs for 24 hours.

Outcome assessment:

CBCT scans will be obtained at 1 week, 3 months, and 6 months postoperatively. Bone density will be measured in Hounsfield units within a 3 x 2.5 mm rectangular region of interest placed across the fracture line above the upper plate, using Planmeca software.

Sample size:

A sample of 40 patients (20 per group) was calculated with the OpenEpi calculator from the difference in mean bone density between PRP and control groups reported in a previous randomized trial using the same PRP technique and CBCT schedule (Daif, 2013), with a two-sided significance level of 5% and 80% power.

Statistical analysis:

Data will be analysed in SPSS and presented as mean and standard deviation. Bone density between groups at each time point will be compared with the independent-samples t-test, and change over time within each group with repeated-measures ANOVA. Maxillary and mandibular fractures will be analysed separately as a secondary, exploratory comparison. A p-value below 0.05 will be considered statistically significant.

Ethics:

The study will be conducted in accordance with the Declaration of Helsinki. Written informed consent will be obtained from all participants, and confidentiality of patient data will be maintained.

Patients undergo open reduction and internal fixation of the maxillary or mandibular fracture under general anaesthesia with two titanium miniplates and screws. Autologous platelet-rich plasma is prepared from 12 ml of the patient's venous blood by double centrifugation, activated with calcium chloride and bovine thrombin, and applied as a gel along the fracture line before wound closure. Postoperatively, patients receive antibiotics and anti-inflammatory medication for one week.

Biological: Autologous Platelet-Rich Plasma (PRP)

Patients undergo open reduction and internal fixation of the maxillary or mandibular fracture under general anaesthesia with two titanium miniplates and screws, identical to the experimental arm, without application of platelet-rich plasma. Postoperatively, patients receive antibiotics and anti-inflammatory medication for one week.

Procedure: Open Reduction and Internal Fixation With Titanium Miniplates

Twelve ml of venous blood is collected into sodium citrate tubes and processed at room temperature by double centrifugation (1200 rpm for 20 minutes, then 2000 rpm for 15 minutes). The platelet-rich fraction is retained and platelet-poor plasma discarded; platelet count and smear are checked. Immediately before use, PRP is activated with calcium chloride and bovine thrombin to form a gel, which is applied once along the fracture line after fixation and before wound closure.

Under general anaesthesia, the fracture is exposed through a vestibular incision, manually reduced, and fixed with two titanium miniplates and screws. The wound is closed with Vicryl sutures. All procedures are performed by the same surgical team.

Time frame: 6 months after surgery

Mean bone density in Hounsfield units (HU) measured on cone-beam computed tomography (CBCT) within a 3 x 2.5 mm rectangular region of interest placed across the fracture line above the upper miniplate, using Planmeca software. Measurements are made by an assessor blinded to group allocation. Higher values indicate greater bone mineralization.

Time frame: 1 week and 3 months after surgery

Mean bone density in Hounsfield units measured on CBCT within a 3 x 2.5 mm region of interest across the fracture line above the upper miniplate, using the same method as the primary outcome.

Time frame: 3 months and 6 months after surgery

Mean bone density in Hounsfield units on CBCT at the fracture site, analysed separately for maxillary and mandibular fractures within each group, to compare the effect of platelet-rich plasma between the two fracture sites.

Impact of Autologous Platelet-Rich Plasma on Promoting Bone Regeneration in Maxillary and Mandibular Fractures: A Randomized Controlled Trial