{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,15]],"date-time":"2026-10-15T02:10:11Z","timestamp":1792030211910,"version":"4.4.0"},"reference-count":61,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2021,4,1]],"date-time":"2021-04-01T00:00:00Z","timestamp":1617235200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Medicina"],"abstract":"<jats:p>Obstructive sleep apnea (OSA) syndrome is a multi-factorial disorder. Recently identified pathophysiological contributing factors include airway collapsibility, poor pharyngeal muscle responsiveness, a low arousal threshold, and a high loop gain. Understanding the pathophysiology is of pivotal importance to select the most effective treatment option. It is well documented that conventional treatments (continuous positive airway pressure (CPAP), upper airway surgery, and dental appliance) may not always be successful in the presence of non-anatomical traits, especially in mild to moderate OSA. Orofacial myofunctional therapy (OMT) consists of isotonic and isometric exercises targeted to oral and oropharyngeal structures, with the aim of increasing muscle tone, endurance, and coordinated movements of pharyngeal and peripharyngeal muscles. Recent studies have demonstrated the efficacy of OMT in reducing snoring, apnea\u2013hypopnea index, and daytime sleepiness, and improving oxygen saturations and sleep quality. Myofunctional therapy helps to reposition the tongue, improve nasal breathing, and increase muscle tone in pediatric and adult OSA patients. Studies have shown that OMT prevents residual OSA in children after adenotonsillectomy and helps adherence in CPAP-treated OSA patients. Randomized multi-institutional studies will be necessary in the future to determine the effectiveness of OMT in a single or combined modality targeted approach in the treatment of OSA. In this narrative review, we present up-to-date literature data, focusing on the role of OSA pathophysiology concepts concerning pharyngeal anatomical collapsibility and muscle responsiveness, underlying the response to OMT in OSA patients.<\/jats:p>","DOI":"10.3390\/medicina57040323","type":"journal-article","created":{"date-parts":[[2021,4,1]],"date-time":"2021-04-01T07:23:17Z","timestamp":1617261797000},"page":"323","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":82,"title":["Orofacial Myofunctional Therapy in Obstructive Sleep Apnea Syndrome: A Pathophysiological Perspective"],"prefix":"10.3390","volume":"57","author":[{"given":"Venkata","family":"Koka","sequence":"first","affiliation":[{"name":"Department of Sleep Medicine, Hospital Antoine Beclere, 92140 Clamart, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9802-7716","authenticated-orcid":false,"given":"Andrea","family":"De Vito","sequence":"additional","affiliation":[{"name":"Ear Nose Throat (ENT) Unit, Head &amp; Neck Department, Santa Maria delle Croci Hospital, Romagna Health Service, 48121 Ravenna, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gabriel","family":"Roisman","sequence":"additional","affiliation":[{"name":"Department of Sleep Medicine, Hospital Antoine Beclere, 92140 Clamart, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Michel","family":"Petitjean","sequence":"additional","affiliation":[{"name":"Department of Sleep Medicine, Hospital Antoine Beclere, 92140 Clamart, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Giulio Romano","family":"Filograna Pignatelli","sequence":"additional","affiliation":[{"name":"Ear Nose Throat (ENT) Unit, Head &amp; Neck Department, Santa Maria delle Croci Hospital, Romagna Health Service, 48121 Ravenna, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Davide","family":"Padovani","sequence":"additional","affiliation":[{"name":"Ear Nose Throat (ENT) Unit, Head &amp; Neck Department, Santa Maria delle Croci Hospital, Romagna Health Service, 48121 Ravenna, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Winfried","family":"Randerath","sequence":"additional","affiliation":[{"name":"Clinic of Pneumology and Allergology, Center for Sleep Medicine and Respiratory Care, Institute for Pneumology at the University Witten\/Herdecke, 42699 Solingen, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2021,4,1]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1006","DOI":"10.1093\/aje\/kws342","article-title":"Increased prevalence of sleep-disordered breathing in adults","volume":"177","author":"Peppard","year":"2013","journal-title":"Am. J. Epidemiol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1147","DOI":"10.1001\/archinternmed.2009.138","article-title":"Nocturnal Arrhythmias across a spectrum of obstructive and central sleep-disordered breathing in older men: Outcomes of sleep disorders in older men (MrOS sleep) study","volume":"169","author":"Mehra","year":"2009","journal-title":"Arch. Intern. Med."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1","DOI":"10.3949\/ccjm.86.s1.01","article-title":"Obstructive sleep apnea: A wake-up for better outcomes","volume":"86","year":"2019","journal-title":"Clevel. Clin. J. Med."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"237","DOI":"10.5271\/sjweh.537","article-title":"Sleep-disordered breathing and occupational accidents","volume":"26","author":"Ulfberg","year":"2000","journal-title":"Scand. J. Work Environ. Health"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"996","DOI":"10.1164\/rccm.201303-0448OC","article-title":"Defining phenotypic causes of obstructive sleep apnea. Identification of novel therapeutic targets","volume":"188","author":"Eckert","year":"2013","journal-title":"Am. J. Respir. Crit. Care Med."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"47","DOI":"10.1152\/physrev.00043.2008","article-title":"Pathophysiology of sleep apnea","volume":"90","author":"Dempsey","year":"2010","journal-title":"Physiol. Rev."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"579","DOI":"10.1007\/s11325-017-1613-3","article-title":"Phenotyping the pathophysiology of obstructive sleep apnea using polygraphy\/polysomnography: A review of the literature","volume":"22","author":"Bosi","year":"2018","journal-title":"Sleep Breath"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"3","DOI":"10.1016\/j.smrv.2014.10.003","article-title":"The role of high loop gain induced by intermittent hypoxia in the pathophysiology of obstructive sleep apnoea","volume":"22","author":"Deacon","year":"2015","journal-title":"Sleep Med. Rev."},{"key":"ref_9","first-page":"25","article-title":"Continuous positive airway pressure compliance in patients with obstructive sleep apnea","volume":"15","author":"Afsharpaiman","year":"2016","journal-title":"Tanaffos"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"4763","DOI":"10.1113\/jphysiol.2014.279240","article-title":"Healthy humans with a narrow upper airway maintain patency during quiet breathing by dilating the airway during inspiration","volume":"592","author":"Cheng","year":"2014","journal-title":"J. Physiol."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"797","DOI":"10.1002\/lary.24479","article-title":"Drug-induced sleep endoscopy in sleep-disordered breathing: Report on 1249 cases","volume":"124","author":"Vroegop","year":"2014","journal-title":"Laryngoscope"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"537","DOI":"10.5665\/sleep.4566","article-title":"Tongue stiffness is lower in patients with obstructive sleep apnea during wakefulness compared with matched control subjects","volume":"38","author":"Brown","year":"2015","journal-title":"Sleep"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"231","DOI":"10.1089\/met.2013.0093","article-title":"Neck circumference is a predictor of metabolic syndrome and obstructive sleep apnea in short-sleeping obese men and women. NIDDK Sleep Extension Study","volume":"12","author":"Cizza","year":"2014","journal-title":"Metab. Syndr. Relat. Disord."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1639","DOI":"10.5665\/sleep.4072","article-title":"Tongue fat and its relationship to obstructive sleep apnea","volume":"37","author":"Kim","year":"2014","journal-title":"Sleep"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"185","DOI":"10.1513\/pats.200708-137MG","article-title":"Obesity and obstructive sleep apnea: Pathogenic mechanisms and therapeutic approaches","volume":"5","author":"Schwartz","year":"2008","journal-title":"Proc. Am. Thorac. Soc."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"348","DOI":"10.1183\/09031936.00119210","article-title":"Identification of craniofacial risk factors for obstructive sleep apnoea using three-dimensional MRI","volume":"38","author":"Chi","year":"2011","journal-title":"Eur. Respir. J."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"241","DOI":"10.1164\/rccm.200807-1076OC","article-title":"Relationship between overnight rostral fluid shift and Obstructive Sleep Apnea in nonobese men","volume":"179","author":"Ridolfi","year":"2009","journal-title":"Am. J. Respir. Crit. Care Med."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"21","DOI":"10.2147\/NSS.S124657","article-title":"Obstructive sleep apnea: Current perspectives","volume":"10","author":"Osman","year":"2018","journal-title":"Nat. Sci. Sleep"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1051","DOI":"10.1164\/ajrccm.157.4.9706067","article-title":"The hypotonic upper airway in obstructive sleep apnea: Role of structures and neuromuscular activity","volume":"157","author":"Schwartz","year":"1998","journal-title":"Am. J. Respir. Crit. Care Med."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"789","DOI":"10.1152\/jappl.1988.64.2.789","article-title":"Upper airway pressure-flow relationships in obstructive sleep apnea","volume":"64","author":"Smith","year":"1988","journal-title":"J. Appl. Physiol."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1618","DOI":"10.1152\/japplphysiol.00045.2008","article-title":"Contribution of male sex, age, and obesity to mechanical instability of the upper airway during sleep","volume":"104","author":"Kirkness","year":"2008","journal-title":"J. Appl. Physiol."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"1300","DOI":"10.1164\/ajrccm\/143.6.1300","article-title":"Upper airway collapsibility in snorers and in patients with obstructive hypopnea and apnea","volume":"43","author":"Gleadhill","year":"1991","journal-title":"Am. Rev. Respir. Dis."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"325","DOI":"10.1152\/japplphysiol.00531.2013","article-title":"State-dependent and reflex drives to the upper airway: Basic physiology with clinical implications","volume":"116","author":"Horner","year":"2014","journal-title":"J. Appl. Physiol."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"597","DOI":"10.1016\/0140-6736(91)91651-A","article-title":"Muscle fiber type and habitual snoring","volume":"337","author":"Smirne","year":"1991","journal-title":"Lancet"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"1644","DOI":"10.1152\/japplphysiol.00653.2011","article-title":"Sensorimotor function of the upper-airway muscles and respiratory sensory processing in untreated obstructive sleep apnea","volume":"111","author":"Eckert","year":"2011","journal-title":"J. Appl. Physiol."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"1318","DOI":"10.1002\/lary.5541011211","article-title":"Histopathologic changes in snoring and obstructive sleep apnea syndrome","volume":"10","author":"Woodson","year":"1991","journal-title":"Laryngoscope"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1","DOI":"10.3389\/fneur.2012.00095","article-title":"Functional role of neural injury in obstructive sleep apnea","volume":"3","author":"Saboisky","year":"2012","journal-title":"Front. Neurol."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"1069","DOI":"10.5665\/sleep.2812","article-title":"Respiratory Movement of Upper Airway Tissue in Obstructive Sleep Apnea","volume":"36","author":"Brown","year":"2013","journal-title":"Sleep"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"zsx056","DOI":"10.1093\/sleep\/zsx056","article-title":"Therapeutic CPAP Level Predicts Upper Airway Collapsibility in Patients with Obstructive Sleep Apnea","volume":"40","author":"Landry","year":"2017","journal-title":"Sleep"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"1531","DOI":"10.5664\/jcsm.8600","article-title":"Discriminating the severity of pharyngeal collapsibility in men using anthropometric and polysomnographic indices","volume":"15","author":"Genta","year":"2020","journal-title":"J. Clin. Sleep Med."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"1293","DOI":"10.1164\/rccm.201404-0718OC","article-title":"Clinical predictors of the respiratory arousal threshold in patients with obstructive sleep apnea","volume":"190","author":"Edwards","year":"2014","journal-title":"Am. J. Respir. Crit. Care Med."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"505","DOI":"10.1042\/CS20100588","article-title":"Eszopiclone increases the respiratory arousal threshold and lowers the apnoea\/hypopnoea index in obstructive sleep apnoea patients with a low arousal threshold","volume":"120","author":"Eckert","year":"2011","journal-title":"Clin. Sci."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"408","DOI":"10.1183\/09031936.00062914","article-title":"Quantifying the ventilatory control contribution to sleep apnoea using polysomnography","volume":"45","author":"Terrill","year":"2015","journal-title":"Eur. Respir. J."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"1800674","DOI":"10.1183\/13993003.00674-2018","article-title":"Identifying obstructive sleep apnoea patients responsive to supplemental oxygen therapy","volume":"52","author":"Sands","year":"2018","journal-title":"Eur. Respir. J."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"1413","DOI":"10.1164\/rccm.201601-0099OC","article-title":"Upper-Airway Collapsibility and Loop Gain Predict the Response to Oral Appliance Therapy in Patients with Obstructive Sleep Apnea","volume":"194","author":"Edwards","year":"2016","journal-title":"Am. J. Respir. Crit. Care Med."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1093\/sleep\/zsx094","article-title":"Loop Gain Predicts the Response to upper airway surgery in patients with obstructive sleep apnea","volume":"40","author":"Joosten","year":"2017","journal-title":"Sleep"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"4043","DOI":"10.1113\/JP276206","article-title":"Breath-holding as a means to estimate the loop gain contribution to obstructive sleep apnoea","volume":"596","author":"Messineo","year":"2018","journal-title":"J. Physiol."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"139","DOI":"10.1056\/NEJMoa1308659","article-title":"Upper airway stimulation for obstructive sleep apnea","volume":"370","author":"Strollo","year":"2014","journal-title":"N. Eng. J. Med."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"1701344","DOI":"10.1183\/13993003.01344-2017","article-title":"Role of common hypnotics on the phenotypic causes of OSA: Paradoxical effects of zolpidem","volume":"50","author":"Carberry","year":"2017","journal-title":"Eur. Respir. J."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"1267","DOI":"10.1164\/rccm.201808-1493OC","article-title":"The Combination of Atomoxetine and Oxybutynin Greatly Reduces Obstructive Sleep Apnea Severity. A Randomized, Placebo-controlled, Double-Blind Crossover Trial","volume":"199","author":"Messineo","year":"2019","journal-title":"Am. J. Respir. Crit. Care Med."},{"key":"ref_41","first-page":"857","article-title":"Exercises for the development of muscles of face with view to increasing their functional activity","volume":"59","author":"Rogers","year":"1918","journal-title":"Dental Cosmos"},{"key":"ref_42","first-page":"69","article-title":"Soft tissue changes of the oropharynx in patients with obstructive sleep apnea","volume":"1","author":"Guimaraes","year":"1999","journal-title":"J. Bras Fonoaudiol."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"266","DOI":"10.1136\/bmj.38705.470590.55","article-title":"Didgeridoo playing as alternative treatment for obstructive sleep apnoea syndrome: Randomized controlled trial","volume":"332","author":"Puhan","year":"2006","journal-title":"BMJ"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"zsz168","DOI":"10.1093\/sleep\/zsz168","article-title":"Apraxia in children and adults with obstructive sleep apnea syndrome","volume":"24","author":"Guilleminault","year":"2019","journal-title":"Sleep"},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"962","DOI":"10.1164\/rccm.200806-981OC","article-title":"Effects of oropharyngeal exercises on patients with moderate obstructive sleep apnea syndrome","volume":"179","author":"Guimaraes","year":"2009","journal-title":"Am. J. Respir. Crit. Care Med."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"1193","DOI":"10.1007\/s11325-016-1332-1","article-title":"Oropharyngeal exercises in the treatment of obstructive sleep apnoea: Our experience","volume":"20","author":"Verma","year":"2016","journal-title":"Sleep Breath"},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"718","DOI":"10.1164\/rccm.201903-0692OC","article-title":"Effect of Weight Loss on Upper Airway Anatomy and the Apnea-Hypopnea Index. The Importance of Tongue Fat","volume":"15","author":"Wang","year":"2020","journal-title":"Am. J. Respir. Crit. Care Med."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"683","DOI":"10.1378\/chest.14-2953","article-title":"Effects of Oropharyngeal Exercises on Snoring: A Randomized Trial","volume":"148","author":"Ieto","year":"2015","journal-title":"Chest"},{"key":"ref_49","first-page":"271","article-title":"Obstructive sleep apnea: Focus on myofunctional therapy","volume":"610","author":"Trawitzki","year":"2018","journal-title":"Nat. Sci. Sleep"},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"669","DOI":"10.5665\/sleep.4652","article-title":"Myofunctional Therapy to Treat Obstructive Sleep Apnea: A Systematic Review and Meta-analysis","volume":"38","author":"Camacho","year":"2015","journal-title":"Sleep"},{"key":"ref_51","first-page":"17","article-title":"The role of oral myofunctional therapy in managing patients with mild to moderate obstructive sleep apnea","volume":"2","author":"Baz","year":"2012","journal-title":"PAN Arab. J. Rhinol."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"401","DOI":"10.1164\/rccm.200703-375OC","article-title":"Association between metabolic syndrome and sleep-disordered breathing in adolescents","volume":"176","author":"Redline","year":"2007","journal-title":"Am. J. Respir. Crit. Care Med."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"416","DOI":"10.1016\/j.pcad.2008.03.002","article-title":"Cardiovascular complications of obstructive sleep apnea syndrome: Evidence from children","volume":"51","author":"Bhattacharjee","year":"2009","journal-title":"Prog. Cardiovasc. Dis."},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"518","DOI":"10.1016\/j.sleep.2013.01.013","article-title":"Critical role of myofascial reeducation in pediatric sleep-disordered breathing","volume":"14","author":"Guilleminault","year":"2013","journal-title":"Sleep Med."},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"1025","DOI":"10.1007\/s11325-017-1489-2","article-title":"Can myofunctional therapy increase tongue tone and reduce symptoms in children with sleep-disordered breathing?","volume":"211","author":"Villa","year":"2017","journal-title":"Sleep Breath"},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"1359","DOI":"10.1007\/s11325-019-01929-w","article-title":"Changes in craniofacial and airway morphology as well as quality of life after passive myofunctional therapy in children with obstructive sleep apnea: A comparative cohort study","volume":"23","author":"Chuang","year":"2019","journal-title":"Sleep Breath"},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"176","DOI":"10.1111\/joor.13119","article-title":"Efficacy of oral myofunctional therapy in middle-aged to elderly patients with obstructive sleep apnoea treated with continuous positive airway pressure","volume":"48","author":"Suzuki","year":"2021","journal-title":"J. Oral. Rehabil."},{"key":"ref_58","doi-asserted-by":"crossref","first-page":"281","DOI":"10.1007\/s11325-019-01952-x","article-title":"Tongue peak pressure: A tool to aid in the identification of obstruction sites in patients with obstructive sleep apnea\/hypopnea syndrome","volume":"24","author":"Plaza","year":"2020","journal-title":"Sleep Breath"},{"key":"ref_59","doi-asserted-by":"crossref","first-page":"1051","DOI":"10.1007\/s11325-019-01957-6","article-title":"Development and evaluation of myofunctional therapy support program (MTSP) based on self-efficacy theory for patients with obstructive sleep apnea","volume":"24","author":"Kim","year":"2020","journal-title":"Sleep Breath"},{"key":"ref_60","first-page":"e23123","article-title":"Myofunctional Therapy App for Severe Apnea-Hypopnea Sleep Obstructive Syndrome: Pilot Randomized Controlled Trial","volume":"9","author":"Plaza","year":"2020","journal-title":"JMIR Mhealth Uhealth"},{"key":"ref_61","doi-asserted-by":"crossref","first-page":"387","DOI":"10.1007\/s11325-016-1429-6","article-title":"Myofunctional therapy improves adherence to continuous positive airway pressure treatment","volume":"21","author":"Truksinas","year":"2017","journal-title":"Sleep Breath"}],"container-title":["Medicina"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1648-9144\/57\/4\/323\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,13]],"date-time":"2025-10-13T13:25:41Z","timestamp":1760361941000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1648-9144\/57\/4\/323"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,4,1]]},"references-count":61,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2021,4]]}},"alternative-id":["medicina57040323"],"URL":"https:\/\/doi.org\/10.3390\/medicina57040323","relation":{},"ISSN":["1648-9144"],"issn-type":[{"value":"1648-9144","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,4,1]]}}}