INFLUENCES OF NASAL RESPIRATORY OBSTRUCTION ON CRANIOFACIAL GROWTH INYOUNG MACACA-FUSCATA MONKEYS

This study was conducted to investigate the influences of artificial n asal respiratory obstruction on craniofacial growth in young Macaca fu scata monkeys. Eleven monkeys were used; seven monkeys served as the e xperimental animals and the remaining four as the control animals. Fur ther, the experimental animals were divided into light and heavy obstr uction groups. Nasal respiratory obstruction was created by injecting dental impression material into the nasopharyngeal region. Nasal respi ratory function was evaluated in terms of nasal airway resistance. Cra niofacial structure in the experimental monkeys was compared with the control animals by means of cephalometric analysis, Nasopharyngeal res piratory obstruction was associated with downward and backward rotatio n of the mandible, upward and backward growth of the condyle, divergen t gonial angle, anterior open bite, and spaced dental arch in the lowe r anterior region, These changes were significantly greater in the exp erimental monkeys with heavy respiratory obstruction, The current find ings support the hypothesis that nasal obstruction existing before and during pubertal growth may result in permanent craniofacial deformiti es pertinent to skeletal open bite.