To explore the clinical effect of simultaneous distraction osteogenesis of the maxilla and affected mandible combined with second-stage orthognathic surgery for the treatment of adult hemifacial microsomia to provide a reference for clinical practice.

Twelve adult patients with hemifacial microsomia who underwent simultaneous distraction osteogenesis and second-stage orthognathic surgery from 2006 to 2013 were enrolled. Distraction osteogenesis of the maxilla and malformed lateral mandible and second-stage orthognathic surgery were performed according to each patient′s specific conditions. The height ratio of the mandibular ramus of the affected side to the contralateral side, the shift distance of the chin point and the inclination angle of the screw plane were measured before and after the operation, and the therapeutic effect was evaluated with clinical photographs.

No patients had obvious complications after the operation, the postoperative aesthetic effect was good, and the relationship between the facial shape and occlusion was significantly improved. The cephalometric measurement showed that the height ratio of the mandibular ramus of the affected side to the contralateral side was increased by 23.83% (t = 11.658, P < 0.001), the deviation distance of the chin was corrected, and the chin point moved back to the midline by 6.63 mm (t = 13.042, P < 0.001) on average, and the inclination angle of the occlusal plane was improved and returned to the horizontal plane by 8.83° (t = 15.358, P < 0.001) on average.

The application of simultaneous distraction osteogenesis of the maxilla and mandible combined with secondary orthognathic surgery for the treatment of adult hemifacial microsomia can obtain satisfactory clinical and aesthetic results and has clinical value.

To establish a three-dimensional coordinate system that can accurately measure the recurrence rate after orthognathic surgery, and evaluate and analyze the degree of recurrence.

Data from patients who underwent orthognathic surgery in a hospital were selected to reconstruct three-dimensional images with spiral CT. The two researchers used the multiplane assisted positioning method to fix the points three times and screened them using intra-andintreclass correlation coefficients (ICC). Reproducible and accurate landmark points were drawn to establish different coordinate systems and calculate the facial asymmetry index (AI) to determine the coordinate system with the best mid-sagittal plane symmetry. This coordinate system and lateral radiographs were used to separately measure the recurrence rate, and evaluate and analyze the three-dimensional recurrence degree of orthognathic surgery.

Ten landmark points that may be repeatedly fixed were obtained, including N (nasion), K (K point), ANS(anterior nasal spine), PNS (posterior nasal spine), Ptm(pterygomaxillary fissure), Gn (gnathion), IZ(IZ point), MZ (MZ point), Ms (mastoideale), Cor (coronion) and and Go (gonion). Three coordinate systems were established, and the most suitable coordinate system was the upper edge point of the left infraorbital foramen. The inner upper edge of the right infraorbital foramen and both sides of the midpoint of the ear points constituted the horizontal plane (HP), which passed through the outermost point of the left zygomatic frontal suture and the outermost point of the right zygomatic frontal suture and was perpendicular to the horizontal plane to constitute the coronal plane (CP). It was perpendicular to the two planes to form a sagittal plane (SP). Two-dimensional and three-dimensional measurements of recurrence were performed on 112 patients, and new three-dimensional recurrence evaluation results were obtained. Less than 40% had low recurrence, 40% to 61% had moderate recurrence, and greater than 61% had high recurrence.

This study established a three-dimensional coordinate system suitable for measuring the recurrence rate after orthognathic surgery, obtained a new three-dimensional recurrence evaluation result, and provided a clinical experimental basis for evaluating the effect of orthognathic surgery and improving stability.

This study aimed to elucidate the mechanisms underlying the impaired bone healing capacity in type 1 diabetes (T1DM) by investigating the role of the Hedgehog (Hh) signaling pathway in the impaired healing of cranial defects caused by T1DM.

This study was approved by the experimental animal ethics committee of our hospital. A cranial defect model was established using Akita transgenic mice with spontaneous type Ⅰ diabetes. The impact of T1DM on osteogenic differentiation and the Hh signaling pathway during cranial defect healing was explored by MicroCT scanning and immunohistochemical (IHC) analysis of osteocalcin (Ocn), Indian Hedgehog (Ihh), Patched1 (Ptch1), and zinc finger protein GLI1 (Gli1). Subsequently, the Hh signaling pathway was activated using smoothened agonist (SAG) (10 mg/kg, gavage), and its potential to improve cranial defect healing in T1DM was assessed by MicroCT and IHC staining. Finally, the ability of SAG (1000 nmol/L) to counteract the inhibitory effects of a high-glucose environment (25 mol/L) on osteogenic differentiation of mouse bone marrow mesenchymal stem cells (BMSCs) was investigated through in vitro experiments. Detection methods included Alkaline Phosphatase and Alizarin Red staining, as well as quantitative real-time PCR (qPCR) analysis of the osteogenesis-related genes Alp, Spp1, Bglap, and Sp7.

Akita mice exhibited early, stable, and significant spontaneous T1DM characteristics. On postoperative day 21, the newly formed bone in the cranial defect area of Akita mice showed significant decreases in the bone volume-to-tissue volume ratio, volumetric bone mineral density, and Ocn expression (P < 0.05), with significant downregulation of Ihh, Ptch1, and Gli1 (P < 0.05). Activation of the Hh signaling pathway by SAG significantly mitigated the negative impact of T1DM on cranial defect healing in Akita mice (P < 0.05). Moreover, after SAG treatment, the inhibitory effects of the high-glucose environment on the alkaline phosphatase activity and in vitro mineralization capacity of BMSCs were significantly alleviated (P < 0.05), and the expression levels of osteogenic differentiation-related genes were significantly upregulated (P < 0.05).

T1DM inhibits cranial defect healing in Akita mice by suppressing the expression of the Hh signaling pathway, whereas activation of the Hh signaling pathway promotes osteogenesis and ameliorates the inhibitory effects of T1DM on bone healing.