Relative rather than absolute macroglossia in patients with Down syndrome: implications for treatment of obstructive sleep apnea.

BACKGROUND: Children with Down syndrome are described as having macroglossia as well as midface hypoplasia. We reviewed anatomic parameters on MRI to determine whether adolescents with Down syndrome have true macroglossia or relatively large tongues compared to the small size of their oral cavity. This has implications for the treatment of obstructive sleep apnea, which occurs at a relatively high rate among patients with Down syndrome.
OBJECTIVE: To determine whether adolescents with Down syndrome have relative rather than true macroglossia.
MATERIALS AND METHODS: On sagittal and axial MR images, parameters for tongue size (area in sagittal midline), the bony craniofacial confines of the retroglossal pharynx (distance between the mandibular rami and distance between the posterior aspect of the mental mandible and the anterior aspect of the spine), and the size of the tongue relative to the craniofacial bony parameters [tongue area/(transverse diameter x anterior-to-posterior diameter)] were compared between 16 patients with Down syndrome and 16 age- and gender-matched controls.
RESULTS: The tongue area was significantly smaller in patients with Down syndrome (2,432 mm2) than in the control patients (2,767 mm2; P=0.02). The craniofacial bony parameters were also smaller in patients with Down syndrome than in the controls (left-right 69.8 vs. 80.1 mm, P<0.001; anterior-posterior 64.2 vs. 74.9 mm, P<0.001). However, the size of the tongue relative to the craniofacial parameters was larger in the patients with Down syndrome (0.54) than in the controls (0.46; P<0.001).
CONCLUSION: Children with Down syndrome do not have true macroglossia but have relatively large tongues compared to the bony confines of the oral cavity.