Objective:To evaluate the changes of different parts of upper airway after alternating rapid palatal expansion and constriction via three dimensional measurement, compared with the protocol of ra-pid palatal expansion alone.Methods: In the study, 36 patients with retrognathic maxilla were selected and randomized to either group A or group B.The patients in group A were treated with rapid palatal expansion alone.The patients in group B were treated with alternating rapid palatal expansion and constriction.Three dimensional analyses were performed on all pre-and post-treatment cone-beam computed tomography (CBCT) images with the software Dolphin.Results: Two subjects in group B were lost to follow up during the treatment.The gender distributions, ages and all measuring items before treatment had no significant difference between group A and group B (P>0.05).Nasal floor width, nasal lateral width, nasal volume, and nasopharynx volume increased significantly in each group after rapid palatal expansion alone or rapid palatal expansion and constriction (P<0.05).The variations of oropharyngeal volume and hypopharyngeal volume had no significant difference (P>0.05).No significant difference was observed in the nasal floor width and nasal lateral width increment among the anterior, median and posterior parts in each group either (P>0.05).No significant difference in all the measuring items was observed between the two groups (P>0.05).Conclusion:Alternating rapid palatal expansion and constriction could increase the volume of nasal and naopharynx cavities by the similar way of rapid palatal expansion alone, and had no obvious effect on oropharynx and hypopharynx cavities.

Objective:This study was based on digital orthodontic diagnosis work flow for indirect bonding transfer tray model design and three-dimensional (3D) printing, and the aim of this paper was to inspect the dimensional accuracyof 3D printed brackets, which is the foundation of the follow up work and hoped that will illuminate the clinical application of the digital orthodontics work flow.Methods: The samples which consisted of 14 cases of patients with malocclusion from Department of Orthodontics Peking University were selected, including 8 cases with tooth extraction and 6 cases without tooth extraction.All the 14 patients were taken intra-oral scan (Trios 3Shape,Denmark)and cone-beam computed tomography (CBCT, NewTom 3G volumetric scanner, Aperio Service,Italy)shooting after periodontal treatment.STL data and DICOM data were obtained from intraoral scans and CBCT images.Data segmentation, registration, fusion, automatic tooth arrangement, virtual positioning of orthodontic appliance and conversion the coordinates of malocclusion model were all done with self-programming software.The data of 3D printing model with brackets on it were output finally and printed out with EDEN260V (Objet Geometries, Israel) to make indirect bonding transfer tray.Digital vernier caliper was used to measure the length and width of upper and lower left brackets and buccal tubes on those 3D models after removal of surrounding supporting material by ultrasonic vibration and water-spray.Intra-examiner reliability was assessed by using intra-class correlation coefficients (ICC), and one-sample T test was used to compare the measurements with the standard dimensional data of the brackets.Results: There were significant differences which range in 0.04-0.17 mm between the 13 items out of the 19 measurement items.Except for the length of the lower left premolars''brackets, mean values of the other items were greater than the test value.Conclusion: Although the measurement results in the width of brackets and the width and length of the buccal tubes obtained experimentally were slightly larger than the test value,this may not reduce the accuracy of indirect bonding procedure in clinic necessarily.Whether the differences which range in 0.04-0.17 mm would actually affect the retention and positioning of brackets needs to be confirmed by further studies.

Adult ; Humans ; Malocclusion, Angle Class III ; therapy ; Orthodontics ; Orthodontics, Corrective ; methods ; Preoperative Care ; methods

BACKGROUNDThe trachea, bronchus, blood vessel and left atrium plasty can maximumly remove tumor tissus and preserve the functional pulmonary tissues so as to improve patients' quality of life and prolong their survival.

METHODSFrom January 1990 to August 2004, 125 patients with lung cancer underwent trachea, bronchus, bloood vessel and left atrium plasty.

RESULTSThere were 116 patients who underwent bronchoplasty, in which angioplasty was performed concurrently in 26 cases. And reconstruction of superior vena cava was performed in 3 patients, and left atrium plasty in 6 patients. Three patients died after operation.

CONCLUSIONSTrachea, bronchus, blood vessel and left atrium plasty may be a promising direction in thoracic surgery.

Collagen is the building component of temporomandibular joint (TMJ) discs and is often affected by inflammation in temporomandibular disorders.The macromechanical properties of collagen are deteriorated by chronic inflammation.However,the mechanism by which inflammation influences disc function remains unknown.The relationship between the ultrastructure and nanomechanical properties of collagen in inflamed discs should be clarified.Seven-week-old female Sprague-Dawley rats were randomly divided into two groups.Chronic TMJ inflammation was induced by intra-articular injection of complete Freund's adjuvant,and samples were harvested after 5 weeks.Picrosirius staining revealed multiple colours under polarized light,which represented alternative collagen bundles in inflamed discs.Using atomic force microscopy scanning,the magnitude of Young's modulus was reduced significantly accompanied with disordered collagen fibril arrangement with porous architecture of inflamed discs.Transmission electron microscopy scanning revealed a non-uniform distribution of collagen fibres,and oversized collagen fibrils were observed in inflamed discs.Fourier transform infrared microspectroscopy revealed a decrease in 1 338 cm-1/amide Ⅱ area ratio of collagen in different regions.The peak positions of amide Ⅰ and amide Ⅱ bands were altered in inflamed discs,indicating collagen unfolding.Our results suggest that sustained inflammation deteriorates collagen structures,resulting in thedeterioration of the ultrastructure and nanomechanical properties of rat TMJ discs.

OBJECTIVE: This study was performed to evaluate the accuracy and reliability of a newly designed method to achieve mandibular dental model superimposition, using voxel-based cone-beam computed tomography (CBCT) registration. METHODS: Fourteen dry cadaveric mandibles and six teeth extracted from patients with severe periodontitis were used to establish 14 orthodontic tooth-movement models. The protocol consisted of two steps: in the first step, voxel-based CBCT mandible superimposition was performed; the reference comprised the external portion of the symphysis, extending to the first molar. The laser-scanned dental model image was then integrated with the CBCT image to achieve mandibular dental model superimposition. The entire process required approximately 10 minutes. Six landmarks were assigned to the teeth to measure tooth displacement, using tooth displacement on the superimposed laser-scanned mandibles as the reference standard. Accuracy was evaluated by comparing differences in tooth displacement based on the method and the reference standard. Two observers performed superimposition to evaluate reliability. RESULTS: For three-dimensional tooth displacements, the differences between the method and the reference standard were not significant in the molar, premolar, or incisor groups (p > 0.05). The intraclass correlation coefficients for the inter- and intra-observer reliabilities of all measurements were > 0.92. CONCLUSIONS Our method of mandibular dental model superimposition based on voxel registration is accurate, reliable, and can be performed within a reasonable period of time in vitro, demonstrating a potential for use in orthodontic patients.

Objective To investigate the effects of maxillary protraction combined with repetitive rapid palatal expansions and constrictions(RPE/C) vs.rapid palatal expansion(RPE) alone using cone-beam computed tomography(CBCT).Methods Twenty four subjects with maxillary retrusion were recruited and block randomized into either the control group(n=12) or the RPE/C(n=12) group.Control group:facemask protraction after RPE.RPE/C group:facemask protraction after RPE/C.3D reconstruction,landmarks identifying,superimposition and cephalometric analysis were performed to compare the pre-treatment and post-treatment CBCT images.Results One subject in the RPE/C group was lost to follow up during the treatment.Maxilla moved forward[(2.5 ± 1.0) mm] after maxillary protraction with RPE/C,which was significantly greater than that in the control group[(1.6±0.8) mm](P＜0.05).The distance of basion to subspinale (Ba-A) increased[(3.1 ± 1.0) mm] in the RPE/C group,which was significantly greater than that in the control group[(2.2 ± 0.9) mm] (P＜0.05).The amount of forward movement of upper first molars was significantly greater in the RPE/C group(P＜0.05).Conclusions Maxillary protraction with RPE/C might positively affect the forward movement of maxilla compared with the RPE alone protocol with the early treatment of maxillary retrusion patients.

Objective Nasopharynx is an important compartment of the upper airway.It is closely associated with the characteristic craniofacial skeletal pattern related to sleep breathing.The present study aimed to investigate the growth pattern of the nasopharynx during rapid puberty growth period.Methods Thirty non-snoring children (aged 8 to l 1 years old) were selected by means of questionnaires and clinical examination.Periodic yearly follow up using MRI,lateral cephalogram,and polysomnograph (PSG) was done in these children.Fifty-one final mixed longitudinal samples were consisted of 23 children completed three consecutive follow-up,and 5 children completed two consecutive follow-up.The yearly changes of the nasopharynx and craniofacial structures were measured.ANOVA was used to evaluate the yearly growth of the nasopharynx.Correlated analysis was used to explore the potential influencing factors of craniofacial structures.Results The rapid growth period of the nasopharynx located in the age range of 8-10 years old,during which the transverse dimension of the nasopharynx developed rapidly,while the rapid development of the sagittal dimension of the nasopharynx was around 12-13 years old.The growth of the nasopharynx was continuous.The changes in the cross-sectional area of the nasopharynx (⊿ CSA) was positively correlated with the changes in distance between mandible of glossopharyngeus (⊿ M),distance of hyoid to cervical anterior surface (⊿ H-CVP),and anterior pharyngeal distance of glossopharyngeus (⊿ AD) (r =0.363,0.363,0.323,respectively,all P ＜ 0.05).The changes in the volume of the nasopharynx (⊿ V) was positively correlated with the changes in upper facial height (⊿ N-ANS),⊿ M,and ⊿ AD (r =0.336,0.413,0.478,respectively,all P ＜ 0.05).The changes in the sagittal dimension of the nasopharynx (⊿ S) was negatively correlated with angulation in supramental and anatomical horizontal line (⊿ SNB) (r =-0.322,P =0.045).The changes in the transverse dimension of the nasopharynx (⊿ T) was negatively correlated with the changes in adenoid (⊿ A) (r =-0.411,P =0.009).Conclusions The growth and development of the nasopharynx was early and continuous,which could be affected by the development of either maxilla or mandible.

Pyroptosis,an inflammatory caspase-dependent programmed cell death,plays a vital role in maintaining tissue homeostasis and activating inflammatory responses.Orthodontic tooth movement(OTM)is an aseptic force-induced inflammatory bone remodeling process mediated by the activation of periodontal ligament(PDL)progenitor cells.However,whether and how force induces PDL progenitor cell pyroptosis,thereby influencing OTM and alveolar bone remodeling remains unknown.In this study,we found that mechanical force induced the expression of pyroptosis-related markers in rat OTM and alveolar bone remodeling process.Blocking or enhancing pyroptosis level could suppress or promote OTM and alveolar bone remodeling respectively.Using Caspase-1-/-mice,we further demonstrated that the functional role of the force-induced pyroptosis in PDL progenitor cells depended on Caspase-1.Moreover,mechanical force could also induce pyroptosis in human ex-vivo force-treated PDL progenitor cells and in compressive force-loaded PDL progenitor cells in vitro,which influenced osteoclastogenesis.Mechanistically,transient receptor potential subfamily V member 4 signaling was involved in force-induced Caspase-1-dependent pyroptosis in PDL progenitor cells.Overall,this study suggested a novel mechanism contributing to the modulation of osteoclastogenesis and alveolar bone remodeling under mechanical stimuli,indicating a promising approach to accelerate OTM by targeting Caspase-1.

Pyroptosis,an inflammatory caspase-dependent programmed cell death,plays a vital role in maintaining tissue homeostasis and activating inflammatory responses.Orthodontic tooth movement(OTM)is an aseptic force-induced inflammatory bone remodeling process mediated by the activation of periodontal ligament(PDL)progenitor cells.However,whether and how force induces PDL progenitor cell pyroptosis,thereby influencing OTM and alveolar bone remodeling remains unknown.In this study,we found that mechanical force induced the expression of pyroptosis-related markers in rat OTM and alveolar bone remodeling process.Blocking or enhancing pyroptosis level could suppress or promote OTM and alveolar bone remodeling respectively.Using Caspase-1-/-mice,we further demonstrated that the functional role of the force-induced pyroptosis in PDL progenitor cells depended on Caspase-1.Moreover,mechanical force could also induce pyroptosis in human ex-vivo force-treated PDL progenitor cells and in compressive force-loaded PDL progenitor cells in vitro,which influenced osteoclastogenesis.Mechanistically,transient receptor potential subfamily V member 4 signaling was involved in force-induced Caspase-1-dependent pyroptosis in PDL progenitor cells.Overall,this study suggested a novel mechanism contributing to the modulation of osteoclastogenesis and alveolar bone remodeling under mechanical stimuli,indicating a promising approach to accelerate OTM by targeting Caspase-1.