Very fast, high-resolution aggregation 3D detection CAM to quickly and accurately find facial fracture areas.

BACKGROUND AND OBJECTIVE: The incidence of facial fractures is on the rise globally, yet limited studies are addressing the diverse forms of facial fractures present in 3D images. In particular, due to the nature of the facial fracture, the direction in which the bone fractures vary, and there is no clear outline, it is difficult to determine the exact location of the fracture in 2D images. Thus, 3D image analysis is required to find the exact fracture area, but it needs heavy computational complexity and expensive pixel-wise labeling for supervised learning. In this study, we tackle the problem of reducing the computational burden and increasing the accuracy of fracture localization by using a weakly-supervised object localization without pixel-wise labeling in a 3D image space. METHODS: We propose a Very Fast, High-Resolution Aggregation 3D Detection CAM (VFHA-CAM) model, which can detect various facial fractures. To better detect tiny fractures, our model uses high-resolution feature maps and employs Ablation CAM to find an exact fracture location without pixel-wise labeling, where we use a rough fracture image detected with 3D box-wise labeling. To this end, we extract important features and use only essential features to reduce the computational complexity in 3D image space. RESULTS: Experimental findings demonstrate that VFHA-CAM surpasses state-of-the-art 2D detection methods by up to 20% in sensitivity/person and specificity/person, achieving sensitivity/person and specificity/person scores of 87% and 85%, respectively. In addition, Our VFHA-CAM reduces location analysis time to 76 s without performance degradation compared to a simple Ablation CAM method that takes more than 20 min. CONCLUSION: This study introduces a novel weakly-supervised object localization approach for bone fracture detection in 3D facial images. The proposed method employs a 3D detection model, which helps detect various forms of facial bone fractures accurately. The CAM algorithm adopted for fracture area segmentation within a 3D fracture detection box is key in quickly informing medical staff of the exact location of a facial bone fracture in a weakly-supervised object localization. In addition, we provide 3D visualization so that even non-experts unfamiliar with 3D CT images can identify the fracture status and location.

INDIVIDUAL ANATOMICAL VARIABILITY OF THE ANTEROPOSTERIOR LATERAL DIMENSIONS OF THE FACIAL SKULL IN MATURE ADULTS.

Despite the significance of anatomical variability in various specialties, there is currently limited research dedicated to this topic. Most studies focus on the brain, with only a small number examining the human skull, primarily in relation to anatomical variability in childhood. AIM: Therefore, the aim of our work is to determine the individual anatomical variability of the lateral dimensions of the facial section of the adult human skull. MATERIALS AND METHODS: The study included 115 skulls of mature individuals, comprising 35 dry bone specimens from the anatomy museum collection and 80 results from human head CT scans without bone tissue pathologies. To detail the craniometric characteristics of the lateral surface of the facial section of the skull, polygons (polygons) were constructed with dividing of the facial section of the skull is into the orbital-frontal, nasal, and maxillary. The facial profilegram of the skull was formed as a set of predetermined dimensions between facial profile points, presenting a continuous line passing through points gl-n-rhi-ns-pr-id-pg, reflecting the shape, dimensions, and position of the cranial profile of mature adults regardless of sex or cranial type. RESULTS: It was established that the longitudinal anteroposterior dimensions of the facial skull exhibit a certain range of variability in mature individuals depending on gender. For instance, the distance between the points gl-po (glabella-porion) reaches its maximum values in individuals with a brachycranial skull shape, ranging from 107 mm to 130 mm in men and from 104 mm to 128 mm in women. In individuals with a mesocranial skull shape, this parameter gradually decreases to 109-126 mm in men and 107-124 mm in women. A similar decrease is observed in those with a dolichocranial skull shape, where the range is 109-121 mm in men and 109-120 mm in women. The distance between n-po (nasion-porion) in brachycranial and mesocranial individuals remains within 96-123 mm and 102-123 mm, regardless of gender, indicating that this parameter is relatively stable. However, in dolichocranial individuals, this distance decreases to 104-115 mm. CONCLUSIONS: Individual anatomical variability of the anteroposterior lateral dimensions of the facial skeleton in mature individuals has been determined. A more in-depth analysis of the existing range of individual variability in the profile configuration of the facial skull was conducted using sagittal polygons. It was found that the polygons gl-po-n, n-po-rhi, and rhi-po-ns relate to the structure of the bony profile of the orbital-temporal and nasal regions of the facial skull, reflecting the upper, combined orbital-nasal section of the head.

Bifurcation of the mandibular canal according to sex, age, and facial skeletal pattern: a morphological and morphometric study of cone beam computed tomography.

PURPOSE: To assess the presence of mandibular canal bifurcation (BMC) and classify these variations by correlating findings with sex, age and facial skeletal pattern, measurements were made, including height, width, and distance from bifurcation to anatomical cortical bones. METHODS: BMC was identified in cone beam CT exams of 301 patients and classified according to its origin, location, direction, configuration and ending. The height and width of the MC before and after the bifurcation; height and width of the BMC; and distance from BMC to alveolar (C1), buccal (C2), lingual (C3) and basal (C4) bone cortices were measured. All data were correlated with sex, age, and facial skeletal pattern (class I, II, III). The significance level was 5%. RESULTS: 67 BMC (22.26%) were identified in 55 patients (18.28%). Bifurcations were more prevalent in females (p = 0.57), aged 18-39 years (p = 0.40), class I (p = 0.77). Single bifurcations, located in the posterior region of the mandible, originating in the MC, with a superior direction and ending in the retromolar foramen were more prevalent (p > 0.05). Mean cortical measurements were higher in male individuals, with significant differences only at C1 (p = 0.03). The mean height and width of BMC were 2.24 (± 0.62) and 1.75 (± 0.45) mm. There was no association between BMC classification and the variables studied (p > 0.05). CONCLUSION: Approximately 1/5 of the population studied had BMC. There were no associations of BMC presence or characteristics with sex, age, and facial skeletal pattern. The distance from bifurcation to alveolar (superior) cortical bone is greater in male individuals.

[Trauma of the midface : Symptoms, diagnostics and treatment]. / Trauma des Mittelgesichts : Symptomatik, Diagnostik und Therapie.

Midface fractures present a clinical challenge in otorhinolaryngology due to their often complex injury pattern and nonspecific symptoms. Precise diagnostics, including differentiated imaging procedures, are required. Interdisciplinary consultation between otorhinolaryngology, maxillofacial surgery, neurosurgery, and ophthalmology is often necessary. When selecting radiographic modalities, radiation hygiene should be taken into account. Sonography provides a radiation-free imaging alternative for fractures of the nasal framework and anterior wall of the frontal sinus. The goal of treatment is to achieve stable and symmetrical reconstruction. Depending on the injury pattern, different osteosynthesis materials, individual access routes, and various surgical procedures can be used. In clinical practice, the management of midface fractures requires a multidisciplinary, flexible, and pragmatic approach based on the fracture pattern and clinical experience.

Deep Learning-Based Facial and Skeletal Transformations for Surgical Planning.

The increasing application of virtual surgical planning (VSP) in orthognathic surgery implies a critical need for accurate prediction of facial and skeletal shapes. The craniofacial relationship in patients with dentofacial deformities is still not understood, and transformations between facial and skeletal shapes remain a challenging task due to intricate anatomical structures and nonlinear relationships between the facial soft tissue and bones. In this study, a novel bidirectional 3-dimensional (3D) deep learning framework, named P2P-ConvGC, was developed and validated based on a large-scale data set for accurate subject-specific transformations between facial and skeletal shapes. Specifically, the 2-stage point-sampling strategy was used to generate multiple nonoverlapping point subsets to represent high-resolution facial and skeletal shapes. Facial and skeletal point subsets were separately input into the prediction system to predict the corresponding skeletal and facial point subsets via the skeletal prediction subnetwork and facial prediction subnetwork. For quantitative evaluation, the accuracy was calculated with shape errors and landmark errors between the predicted skeleton or face with corresponding ground truths. The shape error was calculated by comparing the predicted point sets with the ground truths, with P2P-ConvGC outperforming existing state-of-the-art algorithms including P2P-Net, P2P-ASNL, and P2P-Conv. The total landmark errors (Euclidean distances of craniomaxillofacial landmarks) of P2P-ConvGC in the upper skull, mandible, and facial soft tissues were 1.964 ± 0.904 mm, 2.398 ± 1.174 mm, and 2.226 ± 0.774 mm, respectively. Furthermore, the clinical feasibility of the bidirectional model was validated using a clinical cohort. The result demonstrated its prediction ability with average surface deviation errors of 0.895 ± 0.175 mm for facial prediction and 0.906 ± 0.082 mm for skeletal prediction. To conclude, our proposed model achieved good performance on the subject-specific prediction of facial and skeletal shapes and showed clinical application potential in postoperative facial prediction and VSP for orthognathic surgery.

Evaluation of Facial Aging in Different Age and Gender Groups With Computed Tomography-Based Calvarium and Face Measurements.

BACKGROUND: The human face is a complex area formed by the combination of many different components and varies among individuals according to gender, age, and ethnicity. OBJECTIVE: The aim of this study was to evaluate age-related changes in the facial and calvarial bones in a large sample of both genders. METHODS: The retrospective study included nontraumatic brain computed tomography scans of 280 Turkish adults. Participants were divided into 7-decade groups with the age ranging from 20 to 89 years. Measurements of the face and calvaria were recorded, and calvarial volume was calculated. The relationship of these parameters with age and gender was examined. RESULTS: Statistically significant differences were observed in all the facial and calvarial measurements, except the transverse diameter of the head, with increasing age in both genders. Regardless of age, no significant differences were found in facial and calvarial measurements between genders. In addition, there was a significant decrease in the calvarial volume in both genders after the seventh decade of life. CONCLUSION: The structure of the face and calvarium continues to change and differentiate throughout life. Taking these changes into account during surgical and facial rejuvenation procedures can help predict outcomes and avoid the use of incorrect techniques.

A novel approach to craniofacial analysis using automated 3D landmarking of the skull.

Automatic dense 3D surface registration is a powerful technique for comprehensive 3D shape analysis that has found a successful application in human craniofacial morphology research, particularly within the mandibular and cranial vault regions. However, a notable gap exists when exploring the frontal aspect of the human skull, largely due to the intricate and unique nature of its cranial anatomy. To better examine this region, this study introduces a simplified single-surface craniofacial bone mask comprising of 6707 quasi-landmarks, which can aid in the classification and quantification of variation over human facial bone surfaces. Automatic craniofacial bone phenotyping was conducted on a dataset of 31 skull scans obtained through cone-beam computed tomography (CBCT) imaging. The MeshMonk framework facilitated the non-rigid alignment of the constructed craniofacial bone mask with each individual target mesh. To gauge the accuracy and reliability of this automated process, 20 anatomical facial landmarks were manually placed three times by three independent observers on the same set of images. Intra- and inter-observer error assessments were performed using root mean square (RMS) distances, revealing consistently low scores. Subsequently, the corresponding automatic landmarks were computed and juxtaposed with the manually placed landmarks. The average Euclidean distance between these two landmark sets was 1.5 mm, while centroid sizes exhibited noteworthy similarity. Intraclass coefficients (ICC) demonstrated a high level of concordance (> 0.988), with automatic landmarking showing significantly lower errors and variation. These results underscore the utility of this newly developed single-surface craniofacial bone mask, in conjunction with the MeshMonk framework, as a highly accurate and reliable method for automated phenotyping of the facial region of human skulls from CBCT and CT imagery. This craniofacial template bone mask expansion of the MeshMonk toolbox not only enhances our capacity to study craniofacial bone variation but also holds significant potential for shedding light on the genetic, developmental, and evolutionary underpinnings of the overall human craniofacial structure.

Skeletal changes after midface surgery in patients with craniofacial deformities: a three-dimensional quantification method.

To determine the skeletal changes after midface surgery in patients with syndromic craniosynostosis who underwent Le Fort III (LFIII), monobloc (MB), or facial bipartition (FB). This was a retrospective study including 75 patients: 33 treated by LFIII, 29 by MB, and 13 by FB. Twenty-five had a diagnosis of Apert, 39 Crouzon, and 11 craniofrontonasal syndrome. A three-dimensional mesh was created from the preoperative scan and registered to the postoperative scan to visualise the advancement. LFIII at age 7-12 years effectuated a higher mean advancement in the maxillary (15.5 mm) and zygomatic (7.6 mm) regions when compared to ≥13 years (10.2 mm and 5.5 mm). After MB, mean advancement of the fronto-orbital region was higher at <7 years (16.4 mm), and similarly lower at ages 7-12 (13.8 mm) and ≥13 (12.5 mm). The mean preoperative inter-dacryon distance (34.4 ± 4.4 mm) was reduced by 8.7 ± 4.2 mm after FB without distraction (n = 10). More advancement was seen when midface surgery was performed at a younger age, due to more severe cases and a desire for overcorrection. The highest mean advancement was observed in the fronto-orbital region. Antero-inferior rotational movement was seen after all three techniques.

Do patients with different craniofacial patterns have differences in upper airway volume? A systematic review with network meta-analysis.

BACKGROUND: Craniofacial skeletal discrepancies have been associated with upper airway dimensions. OBJECTIVE: To identify differences in upper airway volume across different sagittal and vertical skeletal patterns. SEARCH METHODS: Unrestricted literature searches in eight databases/registers for human studies until May 2023. SELECTION CRITERIA: Cross-sectional studies measuring upper airway volumes using three-dimensional imaging in healthy patients of different sagittal (Class I, Class II, and Class III) or vertical (normodivergent, hypodivergent, and hyperdivergent) craniofacial morphology. DATA COLLECTION AND ANALYSIS: Duplicate independent study selection, data extraction, and risk of bias assessment. Random-effects frequentist network meta-analysis was performed followed by subgroup-analyses and assessment of the quality of clinical recommendations (confidence in effect estimates) with the CINeMA (Confidence in Network Meta-Analysis) approach. RESULTS: Seventy publications pertaining to 66 unique studies were included with 56 studies (5734 patients) contributing to meta-analyses. Statistically significant differences were found for total  pharyngeal airway volume, with Class II having decreased airway volume (-2256.06 mm3; 95% Confidence Interval [CI] -3201.61 to -1310.51 mm3) and Class III increased airway volume (1098.93 mm3; 95% CI 25.41 to 2172.45 mm3) compared to Class I. Significant airway volume reductions for Class II were localized mostly at the oropharynx, followed by the palatopharynx, and the glossopharynx. Significant airway volume increases for Class III were localized mostly at the oropharynx, followed by the intraoral cavity, and hypopharynx. Statistically significant differences according to vertical skeletal configuration were seen only for the oropharynx, where hyperdivergent patients had reduced volumes compared to normodivergent patients (-1716.77 mm3; 95% CI -3296.42 to -137.12 mm3). Airway differences for Class II and Class III configurations (compared to Class I) were more pronounced in adults than in children and the confidence for all estimates was very low according to CINeMA. CONCLUSIONS: Considerable differences in upper airway volume were found between sagittal and vertical skeletal configurations. However, results should be interpreted with caution due to the high risk of bias, owing to the retrospective study design, inconsistencies in anatomic compartment boundaries used, samples of mixed children-adult patients, and incomplete reporting. CLINICAL TRIAL REGISTRATION: PROSPERO (CRD42022366928).

Facial Anthropometric Analysis of Gender-Related Characteristics in Computed Tomography.

BACKGROUND: In recent years, facial feminization surgery (FFS) has gained increasing popularity because of increases in transgender individuals and the acceptance of diversity in gender identity. However, there is still a scarcity of anthropometric research to guide evidence-based practices for FFS in Taiwan. AIM AND OBJECTIVES: The purpose of this study was to provide a reference for surgeons to achieve optimal outcomes for patients undergoing FFS. The anthropometric analysis could help surgeons meet patients' specific requirements and improve patients' alignment with their gender identity. MATERIALS AND METHODS: The study group consisted of 100 patients (50 males and 50 females) who had undergone cranial computed tomography at Chang Gung Memorial Hospital in Taiwan because of the indication of blunt injuries to the head and face with suspected skull and facial fractures. The computed tomography images were imported into the OsiriX image software to conduct an anthropometric evaluation. The parameters used in the measurements included 2 aspects: bone and soft tissue anthropometric analysis. RESULTS: Anthropometric data were obtained from 50 males (age 32.6 ± 11.4 years) and 50 females (age 33.7 ± 10.3 years). The results for bone measurements showed that both the forehead bossing length and nasal bone width in the male group were significantly greater. The frontal angle in both bone and soft tissue in the male group was significantly smaller. The chin height and bigonial width in both bone and soft tissue in the male group were significantly greater. Although the average gonial angle was greater in the female group, the difference was not significant. For the measurements of lip projection, the results showed that there was no significant difference. Although this group of Asian males had more acute nasolabial angles, the difference was not statistically significant. However, the average nasofrontal angle among females was significantly more obtuse than among males. CONCLUSION: The results revealed that Asian males tend to have more prominent superior orbital rims, wider nasal bones, and wider and taller mandibles compared with Asian females. Despite showing some trends, the gonial angle and lip projections did not reveal any significant differences, which is likely because of a large amount of variation.

CLINICOROENTGENOLOGICAL PECULIARITIES OF THE CONGENITAL AND ACQUIRED CRANIOFACIAL ANOMALIES.

The aim of the research was to study the relationship between the X-ray changes in the bones of the skull, the structure of the upper respiratory tract and concomitant general somatic diseases in patients with congenital and acquired craniomaxillofacial anomalies. The study included 52 patients aged 1 to 3 and 3 to 7 years, with congenital and acquired lower micrognathia in 19 (36.53±5.3)% and upper micrognathia in 33 (63.46±5.3)%. There were used clinical methods (questioning, examination, palpation), instrumental methods (multispiral computer tomography, X-ray cephalometric analysis of the bones of the facial skeleton, oropharynx, and bony pharynx). The obtained results of the clinical and radiographic examination made it possible to assert that among the patients with congenital defects of the jaws, not only changes in the facial skeleton dominate, mostly in the form of upper micrognathia and, to a lesser extent, lower micrognathia, but also the presence of somatic developmental defects in the form of disorders of the nervous system, pathologies of ENT-organs and ophthalmic defects. The identified malformations caused the violations of a number of important functions: breathing, swallowing, chewing, and speech formation. This connection was followed in particular in patients with syndromic craniosynostosis, namely, underdevelopment of the skull base combined with upper micrognathia and retroposition of the maxillary complex in the skull. The frequency and spectrum of concomitant somatic pathology depended on the nature of dentofacial anomalies. All patients with upper micrognathia had craniostenosis with the deformations of the brain skull and eye sockets. Among the patients with lower micrognathia, all those examined were found to have disorders of the development of the ENT-organs.

Facial fractures: The "bottom-up" approach.

Given the demands of a busy high-volume trauma center, trauma radiologists are expected to evaluate an enormous number of images covering a multitude of facial bones in a short period of time in severely traumatized patients. Therefore, a comprehensive checklist, search pattern, and practical approach become indispensable for evaluation. Moreover, fracture complex classification conveys abundant information in a succinct shorthand fashion, which can be a large asset in a busy high-volume trauma center: reliably helping clinicians communicate urgent findings, make early treatment decisions, and effectively plan surgical approaches. Traditionally, radiologists' approach the CT axial dataset in top-down fashion: navigating their descent craniocaudal. However, a bottom-up approach may be advantageous, especially when it comes to facial fracture complex classification. Four key anatomic landmarks of the face, when evaluated sequentially in bottom-up fashion, are favorable to rapid single-sweep facial fracture characterization: the mandible, the pterygoid plates, the zygoma, and the bony orbits. That is, when done in succession: 1. Clearing the mandible rules out a panfacial smash fracture. 2. Clearing the pterygoid plates effectively rules out a Le Fort I, II, and III fracture. 3. Clearing the zygoma effectively rules out a zygomaticomaxillary complex (ZMC) type fracture. 4. Clearing the bony orbits effectively rules out a naso-orbital-ethmoid (NOE) fracture. Following this process of exclusion and elimination; as one ascends through the face, fracture characterization becomes more manageable and straightforward. Besides identifying all of the fractures and using the appropriate classification system, the radiologist also needs to recognize key clinically relevant soft tissue injuries that may be associated with facial fractures and thus should address these in the report.

Artificial Intelligence Model Trained with Sparse Data to Detect Facial and Cranial Bone Fractures from Head CT.

The presence of cranial and facial bone fractures is an important finding on non-enhanced head computed tomography (CT) scans from patients who have sustained head trauma. Some prior studies have proposed automatic cranial fracture detections, but studies on facial fractures are lacking. We propose a deep learning system to automatically detect both cranial and facial bone fractures. Our system incorporated models consisting of YOLOv4 for one-stage fracture detection and improved ResUNet (ResUNet++) for the segmentation of cranial and facial bones. The results from the two models mapped together provided the location of the fracture and the name of the fractured bone as the final output. The training data for the detection model were the soft tissue algorithm images from a total of 1,447 head CT studies (a total of 16,985 images), and the training data for the segmentation model included 1,538 selected head CT images. The trained models were tested on a test dataset consisting of 192 head CT studies (a total of 5,890 images). The overall performance achieved a sensitivity of 88.66%, a precision of 94.51%, and an F1 score of 0.9149. Specifically, the cranial and facial regions were evaluated and resulted in a sensitivity of 84.78% and 80.77%, a precision of 92.86% and 87.50%, and F1 scores of 0.8864 and 0.8400, respectively. The average accuracy for the segmentation labels concerning all predicted fracture bounding boxes was 80.90%. Our deep learning system could accurately detect cranial and facial bone fractures and identify the fractured bone region simultaneously.

Comparison of Internal and External Distraction in Frontofacial Monobloc Advancement: A Three-Dimensional Quantification.

BACKGROUND: Crouzon syndrome is characterized by complex craniosynostosis and midfacial hypoplasia. Where frontofacial monobloc advancement (FFMBA) is indicated, the method of distraction used to achieve advancement holds an element of equipoise. This two-center retrospective cohort study quantifies the movements produced by internal or external distraction methods used for FFMBA. Using shape analysis, this study evaluates whether the different distraction forces cause plastic deformity of the frontofacial segment, producing distinct morphologic outcomes. METHODS: Patients with Crouzon syndrome who underwent FFMBA with internal distraction [Hôpital Necker-Enfants Malades (Paris, France)] or external distraction [Great Ormond Street Hospital for Children (London, United Kingdom)] were compared. Digital Imaging and Communications in Medicine files of preoperative and postoperative computed tomographic scans were converted to three-dimensional bone meshes and skeletal movements were assessed using nonrigid iterative closest point registration. Displacements were visualized using color maps and statistical analysis of the vectors was undertaken. RESULTS: Fifty-one patients met the strict inclusion criteria. Twenty-five underwent FFMBA with external distraction and 26 with internal distraction. External distraction provides a preferential midfacial advancement, whereas internal distractors produce a more positive movement at the lateral orbital rim. This confers good orbital protection but does not advance the central midface to the same extent. Vector analysis confirmed this to be statistically significant ( P < 0.01). CONCLUSIONS: Morphologic changes resulting from monobloc surgery differ depending on the distraction technique used. Although the relative merits of internal and external distraction still stand, it may be that external distraction is more suited to addressing the midfacial biconcavity seen in syndromic craniosynostosis. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.

The Virtual Surgical Management of Facial Fibrous Dysplasia.

PURPOSE: Fibrous dysplasia (FD) is a benign condition, which is characterized by the replacement of normal bone with fibrous tissue and the deposition of woven bone in an irregular manner. Surgical resection, careful corrective osteotomies as debulking, and recontouring procedures are frequently performed, but can be complicated by postoperative regrowth of the lesion. The main aim of this study was to introduce a computer-guided technique for a predetermined technique of bone contouring of craniofacial FD involving the facial bones. METHODS: This case report was conducted on an 18-year-old girl complaining of unilateral craniofacial dysplasia. Upon clinical examination and radiographic examination, a customized computer-generated bone contouring guide was designed using virtual surgical software for accurate contouring of excess bone in the cranial vault and frontal bone. This guide was virtually designed after importing the multislice computerized tomography scans into the virtual surgical planning software. It was generated based on the mirroring option of the unaffected normal side along the median sagittal plane. In the surgery, the guide was seated in place and 5 mm implant drills were inserted through the guide depth holes. Bone removal was made using surgical burs connecting the guiding depth holes. RESULTS: At the end of the follow-up, the patient showed acceptance of her external appearance with no signs of infection or dehiscence. CONCLUSION: This patient-specific cutting guide shows a promising solution for preplanned bone removal in cases with unilateral craniofacial FD.

Evaluation of the stability of treatment with Herbst appliance associated with Hyrax expander and fixed orthodontics through counterpart analysis: A longitudinal follow-up study.

OBJECTIVE: The aim of this study was to evaluate the stability of treatment with a Herbst appliance associated with Hyrax expander (Stage I), followed by fixed appliances (Stage II) and follow-up for an average of 4 years after Stage II, on dentoskeletal facial structures. METHODS: This study involved 50 adolescents with Angle Class II division 1 malocclusion associated with mandibular retrognathism: Treated Group (TG-25) and Control Group (CG-25). Lateral cephalometric radiographs were taken: T1, immediately before Stage I (TG) or at the beginning of the follow-up period (CG); T2, at the end of Stage I (TG) or the follow-up period (CG); T3, at the end of Stage II (TG); and T4, on average, 4 years after Stage II (TG). Enlow's counterpart analysis and some cephalometric measurements were evaluated. Parametric and non-parametric tests were used (P ≤ 0.05). RESULTS: The ramus alignment variables (P < 0.001), SNB (0.040), ANB (<0.001), 1.PP (P = 0.015), 1.MP (P < 0.001), ms/RLp (P < 0.001), mi/RLp (P < 0.001) and S-LS (P = 0.005) showed differences between TG and CG from T1 to T2. Longitudinally, there were differences in ramus alignment, P = 0.003, T1 > T2 < T3 = T4; SNB, P = 0.016, T1 < T2 = T3 = T4; ANB, P < 0.001, T1 > T2 = T3 = T4; 1.MP, P < 0.001, T1 < T2 = T3 = T4; ms/RLp, P = 0.002, T1 = T2 < T3 = T4; mi/RLp, P < 0.001, T1 < T2 = T3 = T4; S-LS, P < 0.001, T1 > T2 = T3 = T4 and S-LI, P = 0.003, T1 = T2 = T3 > T4. CONCLUSION: The nasomaxillary complex (MCF/PM alignment) tended to a retrusive effect to compensate the degree of mandibular retrusion. The protrusive effect of the lower facial third was evident after the Herbst stage and did not remain stable in the follow-up. The dentoalveolar compensation and improvement in facial profile remained stable.

Micro-CT analysis reveals the changes in bone mineral density in zebrafish craniofacial skeleton with age.

Bone has multiple functions in animals, such as supporting the body for mobility. The zebrafish skeleton is composed of craniofacial and axial skeletons. It shares a physiological curvature and consists of a similar number of vertebrae as humans. Bone degeneration and malformations have been widely studied in zebrafish as human disease models. High-resolution imaging and different bone properties such as density and volume can be obtained using micro-computed tomography (micro-CT). This study aimed to understand the possible changes in the structure and bone mineral density (BMD) of the vertebrae and craniofacial skeleton with age (4, 12 and 24 months post fertilisation [mpf]) in zebrafish. Our data showed that the BMD in the vertebrae and specific craniofacial skeleton (mandibular arch, ceratohyal and ethmoid plate) of 12 and 24 mpf fish were higher than that of the 4 mpf fish. In addition, we found the age-dependent increase in BMD was not ubiquitously observed in facial bones, and such differences were not correlated with bone type. In summary, such additional information on the craniofacial skeleton could help in understanding bone development throughout the lifespan of zebrafish.

Craniofacial Fibrous Dysplasia of the Skull Assisted by Virtual Surgical Planning.

Craniofacial fibrous dysplasia (FD) involves thickening of the skull and facial bones, causing asymmetry and distortion of overlying soft tissues. Surgical contouring is often performed with rotary bur or osteotome, with the goal of matching contralateral unaffected anatomy. This is made technically challenging by having no direct visualization of contralateral structures, and the desire to control depth of resection to match the contour of the unaffected side. In our report, a 13-year-old male presented for surgical evaluation of craniofacial FD affecting the right parietal/temporal bones. A novel virtual surgical planning approach of premade drilling template with numerous pilot guide holes was used to assist bone debulking. The pilot holes allowed precise burring of the dysplastic bone. The patient achieved excellent calvarial contour symmetry without unintended intracranial extension. We believe that virtual surgical planning and drilling depth guides are effective tools in the reconstruction of craniofacial FD.

Comparing diagnosis of midfacial fractures by radiologists and plastic surgeons.

BACKGROUND: Clinicians who manage facial fractures often rely on radiologist interpretations to help with assessment and management. Among treating physicians, facial fractures are categorized into clinically relevant patterns of injury. On the other hand, while radiologists are unsurpassed at identifying individual breaks in the bone, larger fracture patterns are not always conveyed in radiology reports. PURPOSE: This study aims to assess the frequency with which the terminology describing midfacial fracture patterns is concordant among radiologists and treating clinicians. METHODS: The authors identified patients with different patterns of midfacial injury including Le Fort I, Le Fort II, Le Fort III, naso-orbito-ethmoid (NOE), and zygomaticomaxillary complex (ZMC) fractures. Plastic surgery consult notes and radiological imaging reports were reviewed for concordance in documentation of injury patterns. Identification of individual fractures consistent with the diagnosed fracture pattern was also recorded. RESULTS: Radiologists were noted to be highly successful in describing individual fractures of the facial bones, identifying at least two defining components of a fracture pattern in 96% of Le Fort, 88% of NOE, and 94% of ZMC injuries. However, when injury patterns were considered, only 32% of Le Fort, 28% of ZMC, and 6% of NOE fractures were explicitly identified in radiology reports. CONCLUSIONS: Radiologists are highly skilled in discerning individual fractures in facial trauma cases. However, less reliability was seen in the identification of fracture patterns in midfacial injury, with particular weaknesses in descriptions of NOE and ZMC fractures. This data suggests that greater focus on patterns of midfacial injury would improve the clinical applicability of radiological reports.

Use of augmented reality navigation to optimise the surgical management of craniofacial fibrous dysplasia.

The aim of this study was to apply an augmented reality (AR) navigation technique based on a head- mounted display in the treatment of craniofacial fibrous dysplasia and to explore the feasibility and the value of AR in craniofacial surgery. With preoperative planning and three-dimensional simulation, the normal anatomical contours of the deformed area were recreated by superimposing the unaffected side on to the affected side. We completed the recontouring procedures in real time with the aid of an AR navigation system. The surgical outcome was assessed by superimposing the postoperative computed tomographic images on to the preoperative virtual plan. The preparation and operation times were recorded. With intraoperative AR guidance, facial bone recontouring was performed uneventfully in all cases. The mean (SD) discrepancy between the actual surgical reduction and preoperative planning was 1.036 (0.081) mm (range: 0.913 (0.496) to 1.165 (0.498) mm). The operation time ranged from 50 to 80 minutes, with an average of 66.4 minutes. The preoperative preparation time ranged from 26 to 36 minutes, with a mean of 29.6 minutes. AR navigation-assisted facial bone recontouring is a valuable treatment modality in managing craniomaxillofacial fibrous dysplasia and shows benefits in improving the efficiency and safety of this complicated procedure.