# Cephalometrics in Obstructive Sleep Apnea Patients with Mixed Dentition  
[PERSON]  
1 Department of Therapeutic Dentistry, Yerevan State Medical University, Koryun Str. 2, Yerevan 0002, Armenia; [EMAIL_ADDRESS]  
2 Center for Sleep Disorders, <Somnusus- Neurology Clinic, Yerevan 0087, Armenia; [EMAIL_ADDRESS]  
3 Department of Neurology and Neurosurgery, National Institute of Health, Yerevan 0051, Armenia  
4 Department of Pediatric Dentistry and Orthodontics, Yerevan State Medical University, Koryun Str. 2, Yerevan 0002, Armenia; [EMAIL_ADDRESS]  
5 Department of Prosthodotics, Yerevan State Medical University, Koryun Str. 2, Yerevan 0002, Armenia  
5 Correspondence: [EMAIL_ADDRESS]; Tel.: +37-498-880-889  
[PERSON]  
1 Department of Therapeutic Dentistry, Yerevan State Medical University, Koryun Str. 2, Yerevan 0002, Armenia; [EMAIL_ADDRESS]  
2 Center for Sleep Disorders, <Somnus- Neurology Clinic, Yerevan 0087, Armenia; [EMAIL_ADDRESS]  
3 Department of Neurology and Neurosurgery, National Institute of Health, Yerevan 0051, Armenia  
6 Department of Dentistry and Orthodontics, Yerevan State Medical University, Koryun Str.  
upper airways. This disrupts the normal architecture of sleep and causes intermittent hypoxia, which is associated with excessive daytime sleepiness and an increased incidence of cardiovascular, neuropsychiatric, and endocrinological disorders [12; 13; 14]. The sleep bruxism (SB) problem seems to be significant due to the high prevalence of OSA and SB. According to the American Academy of Sleep Medicine (AASM), bruxism is a repetitive jaw-muscle activity characterized by clenching or grinding of the teeth and/or by bracing or thrusting of the mandible [15]. Factors such as age, sex, higher body mass index (BMI), tonsils, adenoids, alcohol and sedative intake are well known to worsen the severity of OSAS [16; 17; 18; 19; 20]. In addition to the risk factors for pediatric OSA, more scientific articles have been published about the role of body position during sleep in the case of pediatric OSA and effective approaches to avoid those sleep positions that worsen the severity of pediatric OSA [21]. Patients with pediatric OSA are more likely to experience obstructive events in the supine position than in other non-lying positions. The body position also affects not only the frequency but also the duration of sleep apnea. It is generally known that patients with positional pediatric OSA are younger and less obese; implying the possibility that such patients may have a less severe respiratory phenotype than non-positional patients [22; 23]. Taking into consideration the authors' debate about the fact that posterior upper airway obstruction causes abnormal facial growth, it will be useful to have a reliable diagnostic method to assess the treatment need. However, the diagnosis of posterior airway obstruction is complicated because of the observation difficulties connected with localization [24; 25; 26; 27]. Several tools were used for diagnosis, including nasal breathing and airflow resistance testing, apnea-hypopnea index (AHI) calculation, nasoendoscopy, lateral cephalometry, and 3D imaging [28; 29]. Each has positive and negative properties. However, there is no consensus on the gold standard for posterior airway obstruction diagnosis. Most often, nasal airway patency is not clearly studied in dental offices and a referral to an ENT doctor is required to establish it. A simple, economical, affordable, and most commonly used method for diagnosing upper airway obstruction is the lateral cephalogram [30].  
This study aimed to investigate the relationship between cephalometric parameters and the severity of pediatric OSA.