Sleep disordered breathing in children with achondroplasia. Part 2. Relationship with craniofacial and airway morphology.

We evaluated the craniofacial and airway morphology in children with achondroplasia complicated by snoring and apnea during sleep (AP group) in comparison with children with snoring and apnea during sleep without chromosomal aberrations (adenoid group) and healthy children without sleep disordered breathing or malalignment (healthy group). Lateral cephalograms in 10 children each (four males and six females) in the three groups were analyzed. When the AP and healthy groups were compared, the AP group showed significantly lower values for facial depth, nasal floor length, point A, point pog, and saddle angle (p<0.01) and significantly higher values for mandibular plane angle and gonial angle (p<0.01) regarding craniofacial morphology and significantly lower values for D-AD1, D-AD2, and upper pharynx (p<0.01) regarding airway morphology. When the AP and adenoid groups were compared, the AP group showed significantly lower values for facial depth, nasal floor length, point A, point pog, and saddle angle (p<0.01) and significantly higher values for mandibular plane angle and gonial angle (p<0.01) regarding craniofacial morphology and significantly lower values for D-AD1, D-AD2, and upper pharynx (p<0.05) regarding airway morphology. Thus, the craniofacial/airway morphology in the AP group was characterized by upper airway stenosis, a retruded position of the chin, and an increased mandibular plane angle due to partial early ossification of cranial bones, and an increased lower facial height due to an increased mandibular angle, which may tend to induce sleep snoring and apnea.

Survey of the present status of sleep-disordered breathing in children with achondroplasia Part I. A questionnaire survey.

An achondroplasia is known to be the inherited disease causing a growth impairment of limb bones. Recently, as a symptom of achondroplasia, a sleep-disordered breathing has been reported. Considering the scientific evidence that the sleep-disordered breathing in children such as that due to tonsillar hypertrophy inhibits somatotropin secretion and causes growth retardation, sleep-disordered breathing in children with achondroplasia may aggravate growth/developmental retardation in addition to the bone growth impairment. However, the present status of the development of sleep-disordered breathing in children with achondroplasia has been unknown. Therefore, in order to clarify the present status of sleep-disordered breathing in children with achondroplasia (AP group), we carried out a questionnaire survey of the breathing state during sleep, growth/development history and the oral state at preschool age and school age in the AP group, and compared the results with previously reported data in healthy children (control group). 1. Among the questionnaire items, the incidences of snoring, apnea, mouth breathing, anterior cross bite, and open bite at preschool age were significantly higher in the AP group than in the control group (P < 0.01) At school age, the AP group showed significantly higher incidences of mouth breathing and cross/open bite (P < 0.01) and snoring and apnea (P < 0.05) than the control group. 2. Height and weight at birth and at the ages of 1.5 and 3 years, excluding birth weight, were significantly lower in the AP group than in the control group (P < 0.01). 3. The chronological age at the initiation of eruption of the deciduous or permanent teeth did not significantly differ between the two groups. Thus, the AP group showed higher incidences of sleep-disordered breathing and malocclusion than the control group, and development of sleep-disordered breathing at preschool age.