Contribution of Body Habitus and Craniofacial Characteristics to Segmental Closing Pressures of the Passive Pharynx in Patients with Sleep-Disordered Breathing

Abstract

Obesity and craniofacial abnormalities may contribute to the pathogenesis of obstructive sleep apnea. The purpose of this study was to evaluate the influence of body habitus and craniofacial characteristics on types of pharyngeal closure. The types of pharyngeal closure were determined by endoscopic evaluations of closing pressures of the passive pharynx in 54 paralyzed and anesthetized patients with sleep-disordered breathing (SDB). Assessment of craniofacial characteristics of the SDB patients and 24 normal subjects were made by lateral cephalometry. As compared with normal subjects, SDB patients demonstrated receded mandibles and long lower faces with downward mandible development. SDB patients with positive closing pressures at both the velopharynx and oropharynx (VP + OP group) demonstrated smaller maxillas and mandibles than those with positive closing pressures at the velopharynx only (VP-only group). Obesity was more prominent in the VP-only group than in the VP + OP group. Our results suggest that obesity and craniofacial abnormalities contribute synergistically to increases in collapsibility of the passive pharyngeal airway in patients with SDB. Furthermore, the relative contribution of obesity and craniofacial anomaly appears to determine the type of pharyngeal closure in SDB.

Síndrome da apnéia e hipopnéia obstrutiva do sono: análise cefalométrica

“…Lower and anterior position of hyoid bone in obese patients seems to be related to increased fat deposition on the tongue, which increases its volume. 26 OSAHS patients presenting maxilla and mandible within normal limits, that is, 96mm and 125mm, respectively, may reveal a retropositioned mandible as well as caudal hyoid bone 27 . Cakirer et al 28 , using two anthropometric measurements -the cranial index (the ratio between the highest cranial width and the highest cranial length, that is, highest width x 100/highest length) and the facial index (the ratio between the nasogenian height and the bizygomatic width, that is, the nasogenian height X 100/bizigomatic length), could determine the patient's facial type.…”

Pharyngeal Airway Space in Subjects with Class II and Class III Facial Deformities

“…Among patients without OSA, there is a relative concordance between the size of the skeletal airway enclosure (maxillomandibular complex and spinal column) and the soft tissue airway (Watanabe et al, 2002). In patients with OSA, a narrow airway can result from excessive soft tissue on a normal skeleton or from normal amounts of soft tissue on a deficient skeleton (White, 2005).…”

Avaliação da faringe de pacientes portadores de apneia obstrutiva do sono, por meio da tomografia computadorizada multislice obtida em vigília e durante o sono

“…O peso excessivo também é característica física predominante em indivíduos com SAOS (22) . Pesquisadores têm encontrado importante correlação entre obesidade e distúrbios do sono, o que leva a considerar que o grau de obesidade está relacionado com a gravidade da SAOS (19,(28)(29)(30) .…”

“…A região RL se estende da ponta da úvula à base da epiglote (11) . Muitos estudos têm sido realizados na tentativa de demonstrar que o tamanho e a morfologia das estruturas que compõem as vias aéreas superiores e as dimensões das estruturas a ela adjacentes influenciam o calibre da via aérea superior dos pacientes com SAOS (5,6,(11)(12)(13)18,29,(32)(33)(34)(35)(36)(37)(38)(39)(40)(41) .…”

“…A SAOS está relacionada, também, ao estreitamento e à obstrução das VAS destes pacientes durante o sono, dados por um aumento do volume tecidual que circunda a via aérea e/ou ao aumento da complacência faríngea e colapso durante a inspiração (9,11,17,29,48) . O maior entendimento desta entidade, contudo, tem levado à multiplicação do número de procedimentos e protocolos para tratamento, sejam eles clínicos ou cirúrgicos, sempre na tentativa de reduzir a massa de tecidos moles adjacentes à via aérea ou de diminuir a suscetibilidade ao colapso da faringe (49) .…”