The aim of this study was to investigate the change in clindamycin phosphate antibacterial properties against Gram-positive bacteria using the platelet-rich fibrin as a carrier matrix, and evaluate the changes in the antibiotic within the matrix. The antibacterial properties of CLP and its combination with PRF were tested in a microdilution test against reference cultures and clinical isolates of Staphylococcus aureus (S. aureus) or Staphylococcus epidermidis (S. epidermidis). Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM) analysis was done to evaluate the changes in the PRF_CLP matrix. Release kinetics of CLP was defined with ultra-performance liquid chromatography (UPLC). According to FTIR data, the use of PRF as a carrier for CLP ensured the structural changes in the CLP toward a more active form of clindamycin. A significant decrease in minimal bactericidal concentration values (from 1000 µg/mL to 62 µg/mL) against reference cultures and clinical isolates of S. aureus and S. epidermidis was observed for the CLP and PRF samples if compared to pure CLP solution. In vitro cell viability tests showed that PRF and PRF with CLP have higher cell viability than 70% after 24 h and 48 h time points. This article indicates that CLP in combination with PRF showed higher antibacterial activity against S. aureus and S. epidermidis compared to pure CLP solution. This modified PRF could be used as a novel method to increase drug delivery and efficacy, and to reduce the risk of postoperative infection.

Despite the remarkable progress in virtual surgical planning in the last few decades, which has made orthognathic surgery results more precise and predictable, there remains an unforeseeable risk of developing mandibular lower border defects after bilateral sagittal split osteotomy (BSSO). These defects can cause visible and palpable irregularities of the lower border of the mandible, thereby worsening the surgical result. The study aimed to evaluate the benefit of injectable platelet-rich fibrin (i-PRF) for contour defect modelling in orthognathic surgery in comparison to conventional orthognathic surgery. i-PRF was used to fill the osteotomy gap in BSSO aiming to stimulate bone tissue formation and reduce the risk of mandibular lower border defect formation. Additionally, the correlation between the concentration of the most important growth factors and interleukins in i-PRF and clinical outcomes of different patients was investigated. Also, the antibacterial activity of i-PRF was tested. Cone-beam computed tomography analysis demonstrated a statistically significant increase of bone volume in the BSSO vertical osteotomy gap when i-PRF was applied during surgery. The findings of the study support the use of an autologous biomaterial for BSSO, utilizing a simple preparation technique and application, while also contributing to a deeper understanding of i-PRF content and properties. Study protocol published in ISRCTN10296235 registry https://doi.org/10.1186/ISRCTN10296235.

Bilateral sagittal split osteotomy (BSSO) is a corrective surgical technique for various mandibular deformities. Due to the complexity of this procedure, few postoperative complications may occur. Mandibular inferior border defect, which can occur postoperatively, may worsen aesthetic outcomes. Bone tissue healing is a challenging process that is based on an interplay of growth factors (GFs), cytokines, chemokines, and other signalling molecules. The abundant content of cells and bioactive molecules in the Platelet-rich fibrin (PRF) enables its potential to be used in orthognathic surgery for bone healing stimulation. This study aimed to evaluate injectable PRF (i-PRF) efficiency for contour defect modeling in orthognathic surgery in comparison to conventional orthognathic surgery.In this study, 21 patients were included. All included patients were randomly assigned to test or control groups. Test group patients underwent BSSO surgery with i-PRF application in the vertical osteotomy site of the mandible. Control group patients did not receive i-PRF during the BSSO surgery. i-PRF was prepared according to the Choukroun protocol. Cone-beam computed tomography (CBCT) was done shortly after the surgery and one year after to evaluate volumetric changes in the vertical osteotomy site in the mandible. Besides, the concentration of growth factors (EGF, VEGF, TGFb1, PDGF) and interleukins (IL8) in i-PRF samples from test group patients were determined using Enzyme-Linked Immunosorbent Assay (ELISA).The CBCT superimposition revealed improved bone formation in the BSSO vertical osteotomy site in the mandible when i-PRF was used to fill the osteotomy gap. Net bone volume change at the vertical osteotomy site remained significantly different between groups (p < 0.05). The application of i-PRF increased volume of newly formed bone in test group patients. Differences between concentration of EGF, VEGF, TGFb1, PDGF and IL8 in i-PRF from test group patients were not associated with bone volume changes.Our results demonstrated that i-PRF can increase bone tissue formation in the osteotomy region and is a simple and beneficial tool to improve surgical outcomes.This project has received funding from the European Union's Horizon 2020 research and innovation programme under the grant agreement No 857287.

Ortognātiskā ķirurģija ir smagu dentofaciālu deformāciju ķirurģiska ārstēšanas metode. Pēc apakšžokļa bilaterālas sagitālas plaknes osteotomijas (BSSO) operācijas var veidoties apakšžokļa kontūras defekts, kas kā žokļu kaulu pakāpe ir vizuāli un caur mīkstiem audiem pal-patori konstatējama un pasliktina operācijas estētisko rezultātu. Šādas komplikācijas biežums ir 12–36 % sagitālas plaknes osteotomijas (SSO) operācijās (Agbaje et al., 2013; Raffaini et al., 2020). Ar trombocītiem bagātinātais fibrīns (PRF) ir biomateriāls, kuru pēdējās desmitgadēs arvien plašāk izmanto mutes, sejas un žokļu ķirurģijā, kā arī brūču dzīšanai un mīksto un cieto audu veidošanās stimulēšanai citās medicīnas nozarēs (Miron et al., 2025). Mutes, sejas un žok-ļu ķirurģijā materiāls ir pierādījis savu iedarbību dažādu patoloģisku stāvokļu ārstēšanā (Temmerman et al., 2018; Tabrizi, Arabion, et al., 2018; Shawky & Seifeldin, 2016; Cho et al., 2020; Tabrizi, Arabion, et al., 2018). Līdz ar to tam ir potenciāls tikt izmantotam arī apakšžokļa kontūras defekta modelēšanai ortognātiskā ķirurģijā. Pētījuma mērķis ir novērtēt PRF efektivitāti apakšžokļa kontūras defekta modelēšanai BSSO operācijās salīdzinājumā ar BSSO operāciju, kas veikta bez PRF pielietošanas. Pētījumā tika iekļauti pacienti, kuriem bija diagnosticētas lie-lās žokļu izmēra anomālijas (pēc Starptautiskās statistiskās slimību un veselības problēmu klasi-fikācijas (SSK-10; K07.0) un kuru ārstēšanai bija plānota ortognātiskā operācija. Pirms operāci-jas visiem pacientiem tika noteikts D vitamīna līmenis. Pacienti ar D vitamīna līmeni ≥ 30 ng/ml tika iekļauti pētījumā un randomizēti sadalīti pētāmā un kontroles grupā. Pētāmās grupas pacien-tiem 24–48 stundas pirms operācijas tika paņemti asins paraugi injicējamā PRF (i-PRF) pagata-vošanai. Pēc i-PRF pagatavošanas tie tika sasaldēti un uzglabāti −80 °C temperatūrā turpmākai mikrobioloģiskai un imunoloģiskai testēšanai. Operācijas laikā pētāmās grupas pacientiem tika pagatavots i-PRF, ar kuru tika aizpildīta apakšžokļa BSSO vertikālās osteotomijas sprauga. Kontroles grupas pacientiem vertikālās osteotomijas rajons netika aizpildīts ar i-PRF vai kādu citu kaulaudus aizvietojošo materiālu. 7–12 dienas un 12 mēnešus pēc operācijas pacientiem tika veikts konusa staru datortomogrāfijas (KSDT) izmeklējums kaula dzīšanas izvērtēšanai. Kopumā pētījumā piedalījās 35 pacienti. 18 no tiem bija vīrieši, 17 bija sievietes. Pacientu ve-cums bija 17–47 gadi.. Veicot statistisko datu analīzi, tika konstatēta statistiski nozīmīga atšķirī-ba neto kaula tilpumā starp pētāmo un kontroles grupu BSSO vertikālās osteotomijas rajonā (p < 0,05). Pētāmās grupas pacientiem, kuriem BSSO operācijā tika pielietots i-PRF, jaunveidotā kaula tilpums bija lielāks. BSSO operācija tika veikta abās žokļa pusēs, un apakšžokļa kontūra pēc SSO tika vērtēta katrā pusē atsevišķi. Tika izvērtēti 35 pacienti ar 70 veiktajām SSO. Pētā-mās grupas pacientiem 13 jeb 31 % SSO rajonos tika konstatēts apakšžokļa apakšējās malas defekts, savukārt 29 jeb 69 % SSO rajonos apakšžokļa apakšējās malas defekti netika konstatēti. Kontroles grupas pacientiem apakšžokļa apakšējās malas defekti tika kontstatēti 9 jeb 32 % SSO rajonos, taču 19 jeb 68 % SSO rajonos apakšžokļa apakšējās malas kontūra tika novērtēta kā līdzena. 21 pacientam i-PRF paraugos, izmantojot ELISA, tika noteikti augšanas faktori un citokīni – transformējošais augšanas faktors (TGF-1), epidermālais augšanas faktors (EGF), asinsvadu endotēlija augšanas faktors (VEGF), trombocītu atvasinātais augšanas faktors (PDGF-BB) un interleikīns 8 (IL-8). Visaugstākā koncentrācijā tika noteikts TGF-1 (37643,8–4854,6 pg/ml). Ievērojami augsta koncentrācija bija arī PDGF-BB (255,3–6049,8 pg/ml). EGF koncentrācija bija 323,8–865,5 pg/ml, bet VEGF – 166,6–697,2 pg/ml. Savukārt IL-8 tika kon-statēts ļoti zemās koncentrācijās – 16,8–57,9 pg/ml. Tika atrasta arī statistiski nozīmīga vidēji cieša pozitīva korelācija (rs = 0,501, p < 0,001) starp PDGF-BB un EGF koncentrācijām un vidēji cieša negatīva korelācija (rs = −0,426, p < 0,01) starp TGF-1 un VEGF koncentrācijām. Starp PDGF-BB un TGF-1, IL-8 un EGF, IL-8 un VEGF tika konstatēta...

Orthognathic surgery is a surgical treatment method for severe dentofacial deformities. Follow-ing mandibular bilateral sagittal split osteotomy (BSSO), contour defects of the lower mandibu-lar border may develop. These defects manifest as visible and palpable irregularities through the soft tissue due to changes in bony architecture, thereby worsening the aesthetic outcome of the surgery. The reported incidence of this complication in sagittal split osteotomy (SSO) proce-dures ranges from 12% to 36% (Agbaje et al., 2013; Raffaini et al., 2020). Platelet-rich fibrin (PRF) is a biomaterial that has gained wide application in oral and maxillofacial surgery over the last decade, as well as in other medical fields, for wound healing and stimulation of soft and hard tissue regeneration (Miron et al., 2025). In oral and maxillofacial surgery, PRF has demonstrated its effectiveness in the treatment of various pathological conditions (Temmerman et al., 2018; Tabrizi, Arabion, et al., 2018; Shawky & Seifeldin, 2016; Cho et al., 2020; Tabrizi, Pourdanesh, et al., 2018) and, therefore, it also has a potential application in the modeling of mandibular contour defects. The aim of this study was to evaluate the effectiveness of PRF in mandibular lower border contour defect modeling during BSSO in comparison to BSSO performed without PRF application. The study included patients diagnosed with major jaw size anomalies (according to the International Statistical Classification of Diseases and Related Health Problems (ICD-10) – K07.0) for whom orthognathic surgery was planned. Prior to surgery, serum vita-min D levels were determined in all patients. Individuals with vitamin D levels ≥ 30 ng/mL we-re enrolled in the study and randomly allocated to the experimental and control groups. In the study group, venous blood samples were taken 24–48 hours before surgery to prepare the PRF. These samples were frozen and stored at −80 °C for further microbiological and immunological testing. During surgery, injectable PRF (i-PRF) was prepared and applied into the osteotomy site at the inferior mandibular border. In the control group the osteotomy site was not filled with any material. To evaluate bone healing, cone-beam computed tomography (CBCT) was per-formed postoperatively at two time points: after 7–12 days and after 12 months. In total, 35 pa-tients were included in the study: 18 were male and 17 were female. The patients’ ages ranged from 17 to 47 years. Statistical analysis revealed a statistically significant difference in net bone volume between the study and control groups in the region of the BSSO vertical osteotomy (p < 0.05). The application of injectable platelet-rich fibrin (i-PRF) during the BSSO procedure was associated with an increased volume of newly formed bone in the study group. BSSO was per-formed bilaterally, and the contour of the inferior border of the mandible was evaluated sepa-rately on each side. Thus, 35 patients with a total of 70 SSO sites were assessed. In the study group, defects of the inferior mandibular border were detected in 13 (31%) SSO sites, whereas no defects were observed in 29 (69%) sites. In the control group, inferior mandibular border defects were detected in 9 (32%) SSO sites, while in 19 (68%) SSO sites the inferior mandibu-lar border contour was assessed as smooth. For 21 patients, i-PRF samples were analyzed using the ELISA to determine growth factor concentrations, including transforming growth factor (TGF-β1), epidermal growth factor (EGF), vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF-BB), and interleukin 8 (IL-8). The highest concentrations were observed for TGF-β1 (from 4854.6 to 37,643.8 pg/mL) and PDGF BB (from 2255.3 to 6049.8 pg/mL). EGF and VEGF were detected in concentrations ranging from 323.8 to 865.5 pg/mL and from 166.6 to 697.2 pg/mL, respectively. IL-8 was found in relatively low concentrations—from 16.8 to 57.9 pg/mL. A statistically significant moderate positive correlation was observed between PDGF BB and EGF concentrations (rs = 0.501, p < 0.001), as well as a moderate negative correlation between TGF-β1 and VEGF concentrations (rs = −0,426, p < 0.01). Weak but statistically significant positive correlations (p < 0.05) were identified between PDGF-BB and TGF-β1, IL-8 and EGF, and IL-8 and VEGF, with correlation coefficients of rs = 0.366, rs = 0.336, and rs = 0.311, respectively. Statistical analysis demonstrated no association between growth factor con-centrations and patient age or sex. Furthermore, no statistically significant correlation was found between protein concentrations and changes in net bone volume. No correlation was identified between protein concentrations and donor age, and no differences in protein concentrations we-re observed between male and female donors (p > 0.05). Likewise, no statistically significant correlation was detected between protein concentrations and net bone volume changes (p > 0.05), indicating that the concentrations of the analysed proteins were not associated with mandibular bone regeneration outcomes in the study group. Antibacterial activity was detected in only one i-PRF sample against Staphylococcus aureus (ZOI 24.8 mm), and no antibacterial activity was observed against Klebsiella pneumoniae, Porphyromonas gingivalis and Fusobacterium nucleatum. In conclusion, all i-PRF samples contained high concentrations of biologically active growth factors, with signifi-cant inter-factor correlations, but no correlation with patient sex or age. i-PRF showed low an-timicrobial activity. The use of i-PRF in BSSO procedures, specifically in the vertical osteotomy region, proved to be an effective method for reducing the risk of mandibular lower border de-fects, as it contributed to increased new bone volume. i-PRF contains a wide range of bioactive proteins, predominantly TGF-β1...