The morphology of alveolar bone of the mandibular second and third molars in skeletal Class III patients.

OBJECTIVES: To investigate the alveolar bone morphology of the mandibular second and third molars in skeletal Class III patients from a buccolingual direction. METHODS: Sixty skeletal Class III patients were recruited. The alveolar bone width, buccal cortical bone thickness and lingual cortical bone thickness were measured in five planes from mesial to distal and at five depths from gingival to root. The effects of the gender of the patients, the second molar lingual inclination and the third molar on alveolar bone width and cortical bone thickness were evaluated. To explore the effect of third molar extraction on alveolar bone morphology, the measurements before and after third molar extraction were compared. RESULTS: The impacted third molar had significantly greater alveolar bone width and thicker buccal cortical bone at the cervical third of the molar, while the erupted third molar had greater alveolar bone width at the apical third. Three weeks after third molar extraction, these advantages would weaken owing to the reconstruction of the alveolar bone. Patients with lingually inclined molar were observed to own thicker lingual cortical bone. Males tended to have greater alveolar bone width, but no significant differences were shown in this study. CONCLUSIONS: The growth of the third molar and the second molar lingual inclination affect the alveolar bone morphology of the mandibular second and third molars significantly, but gender has trivial effects on the morphology. The alveolar bone morphology of the mandibular second and third molars would change 3 weeks after third molar extraction.

Differences in the effects of orthodontic treatment on airway-craniocervical functional environment in adult and adolescent patients with skeletal class II high-angle: a retrospective pilot study.

INTRODUCTION: This retrospective cohort study aimed to compare the change in upper airway and craniocervical posture after orthodontic treatment between adolescent and adult patients with Class II high-angle malocclusion. METHODS: A total of 12 adolescent (mean ± standard deviation age = 13.0 ± 2.0 years) and 12 adult patients with Class II high-angle malocclusion (mean ± standard deviation age = 23.7 ± 6.4 years) were selected in this study. The lateral cephalograms and cone beam computed tomography images of adolescent and adult patients were taken before and after treatment, which can be employed to evaluate the variables of craniofacial morphology, upper airway, and craniocervical posture through paired t tests, respectively. An independent sample t test was performed to observe the differences between two groups after orthodontic intervention. For adults and adolescents, the correlation between craniofacial morphology, upper airway, and craniocervical posture was determined through Pearson correlation analysis. RESULTS: In all subjects, the improvements in vertical and sagittal facial morphology after treatment were observed. Anterior and inferior movements of the hyoid bone, an increase of upper airway dimension, posterior tipping of the head and a reduction of cervical inclination in the lower and middle segments post-treatment were identified in adolescence (P < 0.05). Adults displayed anterior movements of the hyoid bone, whereas no significant difference was observed in upper airway dimension and craniocervical posture (P < 0.05). Notable differences were identified in the change of hyoid position and airway volume between two groups (P > 0.05). Mandibular plane inclination, growth pattern, occlusal plane inclination, and chin position were all significantly correlated with craniocervical posture in adolescent patients. Besides, the mandibular growth pattern and chin position in adult patients were significantly correlated with craniocervical posture (P < 0.05). CONCLUSIONS: Orthodontic treatment is capable of enhancing the facial profile of patients with skeletal class II high-angle while improving their upper airway morphology and craniocervical posture, where adolescents and adults differ substantially in that the former exhibit a more favorable alteration in the airway-craniocervical functional environment.

Remote Activation of M2 Macrophage Polarization via Magneto-Mechanical Stimulation To Promote Osteointegration.

Osteoimmunomodulation has been considered to play a key role in osteointegration of orthopedic biomaterials. However, regulation of the macrophage phenotype in vivo with a spatiotemporal controllable way still remains a challenge. In this study, we designed a novel magnetic-responsive mineralized collagen coating to exert remotely controlled magneto-mechanical stimulation on macrophages using an external magnetic field. The magneto-mechanical stimulation exhibited immunomodulatory capability to activate M2 macrophage polarization via triggering the integrin-related cascade pathway and suppressing the phosphorylation of JNK in the MAPK pathway. The optimized inflammatory microenvironment subsequently promoted the osteogenic differentiation of bone marrow-derived mesenchymal stem cells and the osteointegration in vivo. This work, therefore, provides a remote spatiotemporal controllable strategy to promote the osteointegration of orthopedic biomaterials via regulation of the osteoimmune microenvironment.

Regulation of Macrophage Polarization by Mineralized Collagen Coating to Accelerate the Osteogenic Differentiation of Mesenchymal Stem Cells.

Osteogenesis on the interface between the implant and host bone is a synergistic processing of multiple systems involved in immune response, angiogenesis, osteogenesis, etc. However, regulation of the osteoimmune microenvironment on the implant surface to accelerate the osteogenesis through manipulating the polarization of macrophage phenotype is still beginning to be explored. We here demonstrate that macrophage phenotype is able to be regulated by decoration of mineralized collagen (MC) coating on the titanium implant surface via triggering the integrin-related cascade pathway of macrophages. Furthermore, regulation of the macrophage polarization and construction of the osteoimmune microenvironment by MC coating would subsequently accelerate the osteogenic differentiation of the mesenchymal stem cells. This work therefore emphasizes the importance of the osteoimmune microenvironment on osteogenesis and provides a promising strategy to improve the osteointegration of implants.

Automatic detection of oral cancer in smartphone-based images using deep learning for early diagnosis.

SIGNIFICANCE: Oral cancer is a quite common global health issue. Early diagnosis of cancerous and potentially malignant disorders in the oral cavity would significantly increase the survival rate of oral cancer. Previously reported smartphone-based images detection methods for oral cancer mainly focus on demonstrating the effectiveness of their methodology, yet it still lacks systematic study on how to improve the diagnosis accuracy on oral disease using hand-held smartphone photographic images. AIM: We present an effective smartphone-based imaging diagnosis method, powered by a deep learning algorithm, to address the challenges of automatic detection of oral diseases. APPROACH: We conducted a retrospective study. First, a simple yet effective centered rule image-capturing approach was proposed for collecting oral cavity images. Then, based on this method, a medium-sized oral dataset with five categories of diseases was created, and a resampling method was presented to alleviate the effect of image variability from hand-held smartphone cameras. Finally, a recent deep learning network (HRNet) was introduced to evaluate the performance of our method for oral cancer detection. RESULTS: The performance of the proposed method achieved a sensitivity of 83.0%, specificity of 96.6%, precision of 84.3%, and F1 of 83.6% on 455 test images. The proposed "center positioning" method was about 8% higher than that of a simulated "random positioning" method in terms of F1 score, the resampling method had additional 6% of performance improvement, and the introduced HRNet achieved slightly better performance than VGG16, ResNet50, and DenseNet169, with respect to the metrics of sensitivity, specificity, precision, and F1. CONCLUSIONS: Capturing oral images centered on the lesion, resampling the cases in training set, and using the HRNet can effectively improve the performance of deep learning algorithm on oral cancer detection. The smartphone-based imaging with deep learning method has good potential for primary oral cancer diagnosis.

Evaluating the effect of midpalatal corticotomy-assisted rapid maxillary expansion on the upper airway in young adults using computational fluid dynamics.

Midpalatal corticotomy-assisted rapid maxillary expansion (MCRME) is a minimally invasive treatment of maxillary transverse deficiency (MTD) in young adults. However, the effect of MCRME on respiratory function still needs to be determined. In this study, we evaluated the changes in maxillary morphology and the upper airway following MCRME using computational fluid dynamics (CFD). Twenty patients with MTD (8 males, 12 females; mean age 20.55 years) had cone-beam computed tomography (CBCT) images taken before and after MCRME. The CBCT data were used to construct a three-dimensional (3D) upper airway model. The upper airway flow characteristics were simulated using CFD, and measurements were made based on the CBCT images and CFD. The results showed that the widths of the palatal bone and nasal cavity, and the intermolar width were increased significantly after MCRME. The volume of the nasal cavity and nasopharynx increased significantly, while there were no obvious changes in the volumes of the oropharynx and hypopharynx. CFD simulation of the upper airway showed that the pressure drop and maximum velocity of the upper airway decreased significantly after treatment. Our results suggest that in these young adults with MTD, increasing the maxillary width, upper airway volume, and quantity of airflow by MCRME substantially improved upper airway ventilation.

The Treatment Strategy of Cleidocranial Dysplasia: Combined Orthodontic and Orthognathic Treatment.

Cleidocranial dysplasia is a rare autosomal-dominant condition that affects ossification. The main symptoms of this cleidocranial dysplasia patient include craniofacial abnormalities, hypoplasia of clavicles, narrow thorax, retarded exfoliation of deciduous teeth, retarded eruption of permanent teeth, and multiple impacted supernumerary teeth. The aim of this treatment was to correct the craniofacial abnormalities and provide an adequate functional reconstruction of the occlusion. The patient was treated with a multidisciplinary therapeutic protocol including removal of supernumerary teeth, surgical exposure of impacted teeth, orthodontic, and orthognathic surgery. After 6 years' follow-up, the treatment objectives of acceptable occlusion, normal function, and acceptable profile were achieved.