Mechanisms of oxygenation responses to proning and recruitment in COVID-19 pneumonia

Purpose This study aimed at investigating the mechanisms underlying the oxygenation response to proning and recruitment maneuvers in coronavirus disease 2019 (COVID-19) pneumonia. Methods Twenty-five patients with COVID-19 pneumonia, at variable times since admission (from 1 to 3 weeks), underwent computed tomography (CT) lung scans, gas-exchange and lung-mechanics measurement in supine and prone positions at 5 cmH(2)O and during recruiting maneuver (supine, 35 cmH(2)O). Within the non-aerated tissue, we differentiated the atelectatic and consolidated tissue (recruitable and non-recruitable at 35 cmH(2)O of airway pressure). Positive/negative response to proning/recruitment was defined as increase/decrease of PaO2/FiO(2). Apparent perfusion ratio was computed as venous admixture/non aerated tissue fraction. Results The average values of venous admixture and PaO2/FiO(2) ratio were similar in supine-5 and prone-5. However, the PaO2/FiO(2) changes (increasing in 65% of the patients and decreasing in 35%, from supine to prone) correlated with the balance between resolution of dorsal atelectasis and formation of ventral atelectasis (p = 0.002). Dorsal consolidated tissue determined this balance, being inversely related with dorsal recruitment (p = 0.012). From supine-5 to supine-35, the apparent perfusion ratio increased from 1.38 +/- 0.71 to 2.15 +/- 1.15 (p = 0.004) while PaO2/FiO(2) ratio increased in 52% and decreased in 48% of patients. Non-responders had consolidated tissue fraction of 0.27 +/- 0.1 vs. 0.18 +/- 0.1 in the responding cohort (p = 0.04). Consolidated tissue, PaCO2 and respiratory system elastance were higher in patients assessed late (all p < 0.05), suggesting, all together, "fibrotic-like" changes of the lung over time. Conclusion The amount of consolidated tissue was higher in patients assessed during the third week and determined the oxygenation responses following pronation and recruitment maneuvers

Postsurgical Orthodontic Treatment Planning: a Case Report with 20 Years Follow-up

Background: Traditionally, maxillofacial deformities are corrected surgically after an initial orthodontic treatment phase. However in, this article, the authors emphasize the postsurgical therapeutic protocol which is extremely important for determining the final and permanent retention of the corrected occlusion.Methods: A 55 year old female with severe skeletal Class II malocclusion is presented. Combined surgical and orthodontic correction of the malocclusion was used.Results: The step-by-step procedure the authors followed for the postsurgical therapy is described. The goals of the postoperative therapy were to restore and rehabilitate neuromuscular function, obtain occlusal stabilization, grind teeth selectively, and final occlusion retention. The importance of a surgical occlusal splint for rehabilitating stomatognathic neuromuscular function postoperatively was demonstrated. Furthermore, the orthodontic-prosthodontic treatment ensured occlusion stability after the surgical correction. The long-term results confirmed the efficacy of the treatment protocol presented here from both functional and aesthetical perspectives.Conclusions: Postsurgical orthodontic treatment is an important step in the surgical and orthodontic therapy of maxillofacial deformities

Effects on the Facial Growth of Rapid Palatal Expansion in Growing Patients Affected by Juvenile Idiopathic Arthritis with Monolateral Involvement of the Temporomandibular Joints: A Case-Control Study on Posteroanterior and Lateral Cephalograms

Background: Juvenile idiopathic arthritis (JIA) affecting temporomandibular joints (TMJ) in growing patients results in maxillofacial deformities, especially if only one condyle has been affected by the rheumatic disease. Mandibular hypoplasia is the most common issue and it may be associated with maxillary hypoplasia. The aim of this retrospective case-control study is to evaluate the effects of rapid maxillary expansion (RME) in these patients. Methods: 25 growing patients affected by maxillary hypoplasia, currently in a quiescent phase of JIA for at least one year and monolateral involvement of the TMJs, were treated with RME. Data gathered from posteroanterior and lateral cephalograms before and after 1 year from RME were compared to those of 25 non-JIA controls. Results: Nasal cavity width, maxillary width and upper and lower intermolar width statistically increased. Maxillary and mandibular symmetry indexes presented a statistically significant increase, so did the skeletal class. No signs or symptoms of TMJ activity of JIA occurred according to Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) criteria. No difference was found when comparing JIA and non-JIA patients apart from the better improvement of several mandibular symmetry indexes in the affected TMJ side of JIA patients. This event is allegedly due to a worse baseline asymmetry in JIA patients that underwent a bigger relative improvement after treatment. Conclusions: Results suggest that solving maxillary hypoplasia and, therefore, premature contacts are likely to have allowed mandibular repositioning and condylar growth. RME is a safe and effective solution that can substantially improve maxillary and mandibular symmetry in growing patients affected by JIA with TMJ involvement

Early Treatment with a Slow Maxillary Ni–Ti Leaf Springs Expander

The aim of this brief report is to analyse the available literature on the clinical outcomes of a particular appliance for slow maxillary expansion that consists of one or more nickel–titanium springs. Materials and methods: The main medical databases (Scopus, Web of Sciences, Pubmed and Google Scholar) were scanned up to January 2020 using “slow maxillary expan*”, “slow palatal expan*”, “leaf expander” and “NiTi Palatal Expander” as keywords. Skeletal changes in the maxilla after expansion with the Leaf Expander (L.E.) or similar appliances were taken into consideration while reviewing relevant manuscripts. The review focuses on the comparison between the L.E. and conventional expanders (i.e., Haas and Hyrax) regarding the increase in both the distance between the palatal cusps of the upper first molars and the distance between the palatal cusps of the upper second deciduous molars, as well as the increment of nasal structures and pain connected to expansion procedures. Results: Bibliographic research retrieved 32 articles that were considered eligible for the present study. The limited number of articles currently available in international medical databases is allegedly partly due to the fact that these expanders are currently produced by only one patent holder company, which affects its diffusion. Conclusion: Despite the reduced number of published articles, due to the recent introduction of the L.E. device, most of the authors have found that the effects of the L.E. device are clinically and radiographically comparable to those achievable with the rapid palatal expander

Safety and Effects of the Rapid Maxillary Expander on Temporomandibular Joint in Subjects Affected by Juvenile Idiopathic Arthritis: A Retrospective Study

Background: In Juvenile Idiopathic Arthritis (JIA) temporo-mandibular joints are often affected causing skeletal and dental malocclusions. The most frequent condition is mandibular hypoplasia, that may be associated with maxillary hypoplasia. The aim of this retrospective case control study is to investigate the effects and the safety of rapid maxillary expansion (RME) in growing patients affected by JIA. It was evaluated whether RME could be performed without complications on TMJs of JIA patients using DC/TMD protocol, and naso-maxillary transversal parameters were compared with the ones obtained on healthy patients. Methods: Twenty-five patients affected by JIA that ceased to manifest TMJ (Temporo-Mandibular Joint) symptoms in the previous year were treated with RME to solve the maxillary transverse hypoplasia. Postero-anterior cephalometric tracings were collected before and after treatment; linear measurements were obtained to study maxillary and nasal cavity modifications. Data were compared to those of a similar group of twenty-five healthy patients. Paired t-test and Independent t-test were used to evaluate changes before and after treatment in each group and to perform a comparison between the groups. Results: All patients demonstrated a statistically significant increase in nasal cavity width, maxillary width and upper and lower intermolar width. No patients presented a worsening of their TMJs condition. Intragroup comparisons revealed significant changes of cephalometric measurements, but no difference was found when comparing JIA and healthy patients. Conclusions: Growing patients with JIA that ceased to show signs of active TMJ involvement for at least one year could be safely treated with RME, expecting similar benefits to those of healthy patients. Dentists and rheumatologists should be informed of safety and potential benefits of palatal expansion in JIA patients in order to improve the outcome of orthodontic treatment and reduce the indication for more invasive procedures (i.e., Surgical Assisted Rapid Maxillary Expansion)