Efficacy of Rapid Maximillary Expansion with or without Previous Adenotonsillectomy for Pediatric Obstructive Sleep Apnea Syndrome Based on Polysomnographic Data: A Systematic Review and Meta-Analysis  
[PERSON]  
1 Department of Health, Life and Environmental Science, University of L'Aquila, Piazza [PERSON], 67100 L'Aquila, Italy; [EMAIL_ADDRESS] (V.Q. ); [EMAIL_ADDRESS] (R.J.M. ); [EMAIL_ADDRESS] (S.G.); [EMAIL_ADDRESS] (G.M.) 2 Academy of Orofacial Myofunctional Therapy (AOMT), 910 Via De La Paz, Ste. 106, Pacific Palisades, CA 90272, USA; [EMAIL_ADDRESS]  
[PERSON]  
1 Department of Health, Life and Environmental Science, University of L'Aquila, Piazza [PERSON], 67100 L'Aquila, Italy; [EMAIL_ADDRESS] (V.Q. ); [EMAIL_ADDRESS] (R.J.M. ); [EMAIL_ADDRESS] (S.G.); [EMAIL_ADDRESS] (G.M.) 2 Academy of Orofacial Myofunctional Therapy (AOMT), 910 Via De La Paz, Ste. 106, Pacific Palisades, CA 90272, USA; [EMAIL_ADDRESS]  
[PERSON]  
1 Department of Health, Life and Environmental Science, University of L'Aquila, Piazza Salvatore Tommasi, 67100 L'Aquila, Italy; [EMAIL_ADDRESS] (V.Q. ); [EMAIL_ADDRESS] (R.J.M. ); [EMAIL_ADDRESS] (S.G.); [EMAIL_ADDRESS] (G.M.) [PERSON]  
1 Department of Health, Life and Environmental Science, University of L'Aquila, Piazza Salvatore Tommasi, 67100 L'Aquila, Italy; [EMAIL_ADDRESS] (V.Q. ); [EMAIL_ADDRESS] (R.J.M. ); [EMAIL_ADDRESS] (S.G.); [EMAIL_ADDRESS] (G.M.) 2 Academy of Orofacial Myofunctional Therapy (AOMT), 910 Via De La Paz, Ste. It is common in children with a prevalence ranging between 1.2 and 5.8% of the general pediatric population (<18 years old) [2]. Although the etiopathogenesis of this disorder in adults is known, many characteristics of this syndrome in children are debated. OSAS and is known to be highly connected to the size of the upper airways and adenoid tissue [5] OSAS can and have different levels of severity that could give rise to long term effects on children including alterations in behavior and neurocognitive deficits affecting attention, learning and memory as well as executive and motor functions [1; 3]. According to the American Academy of Sleep Medicine (AASM) both appeas and hypopneas are observed in this syndrome. Apnea is known as the interruption of airflow for 10 s or more, while hypopnea is a reduction of >30% in air flow for a period lasting at least 10 s associated with a >3% decrease in oxygen saturation or arousals [6]. According to the AASM the diagnosis is based on both nocturnal and daytime symptoms and a well-documented full-night polysomnography [7]. For an OSAS diagnosis a threshold of 15 events per hour of recording is applied. The apnea-hypopnea index (AHI) that calculates the sum of the apneas and hypopneas per hour of sleep defines the severity of OSAS. It can be classified as a mild OSAS (AHI = 1 to 4.9), moderate OSAS (AHI = 5 to 9.9) or severe OSAS (AHI > 10) [6; 7; 8]. While obesity is considered to be a major cause of OSAS in adults, adenotonsillar hypertrophy (ATH) which may increase airways resistance, is thought to be the prime cause of childhood OSAS [4; 8; 9], as it contributes to the narrowing of the retro-palatal area that already has the smallest cross-sectional area and therefore is the prevalent site of obstruction [5; 9; 10; 11]. In literature it is seen that ATH leads not only to problems related to mouth breathing, snoring, chronic sinusitis, nasal congestion, hyponasal speech, but also to emotional disorders and poor neurological development [7]. When fat is present in the area of the pharyngeal soft tissue it decreases the caliber of the lumen and it also increases the collapse of the structures [5; 9; 11]. Additionally, the increased occurrence of fat in the thoracic and abdominal walls importantly reduces the respiratory function in these patients [5]. In fact, obese and overweight children compared to normal-weight children present a higher risk of developing OSAS [5; 10; 12].