The analysis aims at assessing the current trends in orthognathic surgery. The retrospective study covered a group of 124 patients with skeletal malocclusion treated by one team of maxillofacial surgeons at the University Hospital in Zielona Góra, Poland. Various variables were analysed, including demographic characteristics of the group, type of deformity, type of osteotomy used, order in which osteotomy was performed and duration of types of surgery. The mean age of the patients was 28 (ranging from 17 to 48, SD = 7). The group included a slightly bigger number of females (59.7%), with the dominant skeletal Class III (64.5%), and asymmetries were found in 21.8% of cases. Types of osteotomy performed during surgeries were divided as follows: LeFort I, segmental LeFort I, BSSO, BSSO with genioplasty, LeFort I with BSSO, LeFort I with BSSO and genioplasty, segmental LeFort I with BSSO, isolated genioplasty. Bimaxillary surgeries with and without genioplasty constituted the largest group of orthognathic surgeries (49.1%), and a slightly smaller percentage were one jaw surgeries (46.7%). A statistically significant correlation was found between the type of surgery and the skeletal class. In patients with skeletal Class III, bimaxillary surgeries were performed significantly more often than in patients with skeletal Class II (57.5% vs. 20.0%; p = 0.0002). The most common type of osteotomy in all surgeries was bilateral osteotomy of the mandible modo Obwegeser–Epker in combination with Le Fort I maxillary osteotomy (42.7%). The order of osteotomies in bimaxillary surgeries was mandible first in 61.3% of cases. The longest surgery was bimaxillary osteotomy with genioplasty (mean = 265 min), and the shortest surgery was isolated genioplasty (mean = 96 min). The results of the analysis show a significant differentiation between the needs of orthognathic surgery and the types of corrective osteotomy applied to the facial skeleton.

The aim of this study was to compare the reduced stresses according to Huber’s hypothesis and the displacement pattern in the region of the facial skeleton using a tooth- or bone-borne appliance in surgically assisted rapid maxillary expansion (SARME). In the current literature, the lack of updated reports about biomechanical effects in bone-borne appliances used in SARME is noticeable. Finite element analysis (FEA) was used for this study. Six facial skeleton models were created, five with various variants of osteotomy and one without osteotomy. Two different appliances for maxillary expansion were used for each model. The three-dimensional (3D) model of the facial skeleton was created on the basis of spiral computed tomography (CT) scans of a 32-year-old patient with maxillary constriction. The finite element model was built using ANSYS 15.0 software, in which the computations were carried out. Stress distributions and displacement values along the 3D axes were found for each osteotomy variant with the expansion of the tooth- and the bone-borne devices at a level of 0.5 mm. The investigation showed that in the case of a full osteotomy of the maxilla, as described by Bell and Epker in 1976, the method of fixing the appliance for maxillary expansion had no impact on the distribution of the reduced stresses according to Huber’s hypothesis in the facial skeleton. In the case of the bone-borne appliance, the load on the teeth, which may lead to periodontal and orthodontic complications, was eliminated. In the case of a full osteotomy of the maxilla, displacements in the buccolingual direction for all the variables of the bone-borne appliance were slightly bigger than for the tooth-borne appliance.

The analysis aimed at studying stresses reduced according to Huber’s hypothesis and displacement patterns at selected sites of the facial skeleton using a tooth-borne appliance in surgically assisted rapid maxillary expansion. Five different variants of osteotomy of the midface and a variant without surgical intervention were compared to determine the best model for making an incision in the maxilla. The finite element analysis (FEA) was used for the study. Five osteotomy variants and a variant without osteotomy were modelled using a tooth-borne appliance on a facial skeleton model of a 23-year-old woman with skeletal malocclusion. The finite element mesh was constructed based on the geometry imported into the ANSYS 15.0 (Swanson Analysis System of USA) software, in which calculations were performed using the finite element analysis. Stress distributions and displacement patterns along the X, Y and Z axes are presented for each osteotomy variant with the expansion of the tooth-borne appliance at a level of 0.5 mm. As a result of the analysis it was found that osteotomy of the palatal suture in conjunction with Le Fort I osteotomy has the biggest impact on the course of maxillary expansion. If no osteotomy is performed, an increase in stresses reduced according to Huber occurs in the entire facial skeleton with a simultaneous absence of maxillary expansion.

W ostatnich latach ugruntowała się pozycja leczenia interdyscyplinarnego oraz chirurgii ortognatycznej w leczeniu problemów szkieletowych czaszki twarzowej i towarzyszących im wad zgryzu. Rozwój technik chirurgicznych, metod planowania wspieranych technologią 3D, obserwacje kliniczne oraz analizy efektów leczenia doprowadziły do zmiany