Changes in the pharyngeal airway after different orthognathic procedures for correction of class III dysplasia

Posterior airway compromise following orthognathic surgery in skeletal class III patient - A systematic review and meta-analysis

Obstructive Sleep Apnea (OSA) has been proven to have short- and long-term adverse effects on patients. OSA is associated with severe co-morbidities. Clinical studies have evaluated the volumetric changes in the posterior airway space following Orthognathic surgeries. The following study aims to assess the long-term airway compromise following different procedures for correcting skeletal Cl-III relationships. The research followed the PRISMA protocol guidelines and included a comprehensive electronic search of the National Institutes of Health (NIH), PubMed, and Embase databases, utilizing specific inclusion and exclusion criteria. All studies included airway measurements taken at three different time points, ensuring long-term follow-up of at least six months. Two authors evaluated quality blindly. We compared the types of surgical procedures alongside the volumetric airway measurements taken before and after the operation. Meta-analysis was performed using a random effect model if heterogeneity was detected. Otherwise, a common effect model was conducted under a 95 % confidence level. Sixteen publications met the inclusion criteria for qualitative assessment, and nine were eligible for quantitative evaluation. All included studies were rated within low to moderate risk of bias. Posterior airway volume changes in class III patients between the mandible-only and bimaxillary procedures immediately after the surgery were significantly different; p < 0.05. However, this difference between those groups was not found in long-term follow-up, and airway volumes were comparable. In conclusion, the meta-analysis results confirm that bimaxillary and mandible-only surgery similarly decrease the posterior airway space volumes in long-term follow-up.

MSCT 3D Analysis of Nasopharyngeal Airway After Le Fort I Maxillary Setback Surgeries

In recent years, maxillary Le Fort I osteotomy setback has been widely applied in correcting maxilla prognathism. In the meantime, airway considerations have attracted more and more attention. The aim of this research was to observe the alteration of nasopharyngeal airway indexes after maxilla setback and offer evidence for the effectiveness and safety of maxillary Le Fort I setback surgeries. As for a retrospective cross-sectional study, 40 patients diagnosed with maxilla prognathism and undergoing maxillary setback surgeries were enrolled. They were grouped by the type of maxillary setback operations as group A (integral maxillary setback, n=19) and group B (segmental maxillary setback, n=21). Multislice computed tomography data were collected 1 week before (T0) and more than 3 months (T1) after surgery. 3D reconstruction and evaluation of the pharyngeal airway were conducted to analyze nasopharyngeal airway index variation before and after surgery and the difference between group A and group B. Preoperative and postoperative nasopharyngeal airway volume showed no statistical significance in group A (P=0.872) and group B (P=0.169) as well as other indexes of the nasopharynx. The comparison of postoperative airway changes between group A and group B also showed no significant difference. Both integral and segmental maxillary Le Fort I osteotomy setbacks have slight impact on nasopharyngeal airway dimensions and are safe within a specific setback range.

Frontal Sinus Fractures: An Evaluation of Patient Demographics, Mechanisms of Injury, Classification, and Management Strategies in Patients Referred to a Trauma Center, From 2014 to 2019

This retrospective study aimed to present demographic data, mechanisms of injury, anatomical locations, and management strategies in patients with frontal sinus fractures. The study included 91 patients with frontal sinus fractures attending the Rajaee Hospital of Shiraz between 2014 and 2019. The data recorded for each patient included age, sex, injury mechanism, fracture classification, associated craniofacial fractures, nasofrontal duct injury, cerebrospinal fluid leak, and treatment approach. The mean age of patients was 31.0±14.0 years, with male predominance (95.6%). Car crashes represented the most frequent mechanism of frontal sinus fracture, involving 31 subjects (34%). Isolated anterior and posterior table fractures were seen in 32 (35.2%) and 5 (5.5%) patients. Fifty-four patients (59.3%) presented both tables' involvement. Frontal sinus injuries occurred frequently (74.7%) with other facial fractures. Nasofrontal duct injury was found in 7 patients (7.7%), and 13 (14.3%) exhibited cerebrospinal fluid leakage. Fifty patients (55%) were treated with observation alone; 16 (17.5%) underwent sinus preservation, 12 (13.2%) experienced sinus obliteration, and 13 (14.3%) endured cranialization. Fisher's exact test revealed no significant association between the classification of fracture and the mechanism of injury ( P =0.591). However, a significant association was observed between the fracture classification and the treatment applied ( P =0.023). Frontal sinus fractures were most often caused by car crashes in young adults. Combined anterior and posterior table fractures were more commonly found than isolated anterior or posterior table involvement. Most frontal sinus fractures were treated conservatively without DDS surgical operation.

Redefining precision and efficiency in orthognathic surgery through virtual surgical planning and 3D printing: a narrative review

Orthognathic surgery, essential for addressing jaw and facial skeletal irregularities, has historically relied on traditional surgical planning (TSP) involving a series of time-consuming steps including two-dimensional radiographs. The advent of virtual surgical planning (VSP) and 3D printing technologies has revolutionized this field, bringing unprecedented precision and customization to surgical processes. VSP facilitates 3D visualization of the surgical site, allowing for real-time adjustments and improving preoperative stress for patients by reducing planning time. 3D printing dovetails with VSP, offering the creation of anatomical models and surgical guides, enhancing the predictability of surgical outcomes despite higher initial setup and material costs. The integration of VSP and 3D printing promises innovative and effective solutions in orthognathic surgery, surpassing the limitations of traditional methods. Patient-reported outcomes show a positive post-surgery impact on the quality of life, underlining the significant role of these technologies in enhancing self-esteem and reducing anxiety. Economic analyses depict a promising long-term fiscal advantage with these modern technologies, notwithstanding the higher initial costs. The review emphasizes the need for large-scale randomized controlled trials to address existing research gaps and calls for a deeper exploration into the long-term impacts and ethical considerations of these technologies. In conclusion, while standing on the cusp of a technological renaissance in orthognathic surgery, it is incumbent upon the medical fraternity to foster a collaborative approach, balancing innovation with scrutiny to enhance patient care. The narrative review encourages the leveraging of VSP and 3D printing technologies for more efficient and patient-centric orthognathic surgery, urging the community to navigate uncharted territories in pursuit of precision and efficiency in the surgical landscape.

Retrospective Analysis of the Airway Space Changes in Dentofacial Deformity after Two-Jaw Orthognathic Surgery Using Cone Beam Computed Tomography

Orthognathic surgery is used to modify anomalies in maxillomandibular position; this process can significantly affect the anatomy of the airway and cause functional changes. This study aims to define the impact of mandibular maxillary movement on the airway of subjects with dentofacial deformity. A retrospective study was conducted on subjects with Angle class II (CII group) and Angle class III (CIII group) dentofacial deformities. The subjects were treated via bimaxillary surgery; for all of them, planning was performed with software and 3D printing. Cone beam computed tomography (CBCT) was obtained 21 days before surgery and 6 months after surgery and was used for planning and follow-up with the same conditions and equipment. Was used the superimposition technique to obtain the maximum and minimum airway areas and total airway volume. The data were analyzed with the Shapiro-Wilk test and Student's t-test, while Spearman's test was used to correlate the variables, considering a value of p < 0.05. Thus, 76 subjects aged 18 to 55 years (32.38 ± 10.91) were included: 46 subjects were in CII group, treated with a maxillo-mandibular advancement, and 30 subjects were in the CIII group, treated with a maxillary advancement and a mandibular setback. In the CII group, a maxillary advancement of +2.45 mm (±0.88) and a mandibular advancement of +4.25 mm (±1.25) were observed, with a significant increase in all the airway records. In the CIII group, a maxillary advancement of +3.42 mm (±1.25) and a mandibular setback of -3.62 mm (±1.18) were noted, with no significant changes in the variables measured for the airway (p > 0.05). It may be concluded that maxillo-mandibular advancement is an effective procedure to augment the airway area and volume in the CII group. On the other hand, in subjects with mandibular prognathism and Angle class III operated with the maxillary advancement and mandibular setback lower than 4 mm, it is possible to not reduce the areas and volume in the airway.

Subregional pharyngeal changes after orthognathic surgery in skeletal Class III patients analyzed by convolutional neural networks-based segmentation

OBJECTIVES

To evaluate the accuracy of fully automatic segmentation of pharyngeal volume of interests (VOIs) before and after orthognathic surgery in skeletal Class III patients using a convolutional neural network (CNN) model and to investigate the clinical applicability of artificial intelligence for quantitative evaluation of treatment changes in pharyngeal VOIs.

METHODS

310 cone-beam computed tomography (CBCT) images were divided into a training set (n=150), validation set (n=40), and test set (n=120). The test datasets comprised matched pairs of pre- and posttreatment images of 60 skeletal Class III patients (mean age 23.1±5.0 years; ANB<-2⁰) who underwent bimaxillary orthognathic surgery with orthodontic treatment. A 3D U-Net CNNs model was applied for fully automatic segmentation and measurement of subregional pharyngeal volumes of pretreatment (T0) and posttreatment (T1) scans. The model's accuracy was compared to semi-automatic segmentation outcomes by humans using the dice similarity coefficient (DSC) and volume similarity (VS). The correlation between surgical skeletal changes and model accuracy was obtained.

RESULTS

The proposed model achieved high performance of subregional pharyngeal segmentation on both T0 and T1 images, representing a significant T1-T0 difference of DSC only in the nasopharynx. Region-specific differences among pharyngeal VOIs, which were observed at T0, disappeared on the T1 images. The decreased DSC of nasopharyngeal segmentation after treatment was weakly correlated with the amount of maxillary advancement. There was no correlation between the mandibular setback amount and model accuracy.

CONCLUSIONS

The proposed model offers fast and accurate subregional pharyngeal segmentation on both pretreatment and posttreatment CBCT images in skeletal Class III patients.

CLINICAL SIGNIFICANCE

We elucidated the clinical applicability of the CNNs model to quantitatively evaluate subregional pharyngeal changes after surgical-orthodontic treatment, which offers a basis for developing a fully integrated multiclass CNNs model to predict pharyngeal responses after dentoskeletal treatments.