Micrognathia and glossoptosis may cause severe respiratory and feeding diff
iculties in newborns with Pierre Robin syndrome, The growth of the mandible
is alleged to more or less "catch up" during the first year of life. We co
uld not objectify such a catch-up growth using the noninvasive and harmless
measurement of the jaw index, The jaw index is defined as alveolar overjet
x maxillary arch/mandibular arch. The alveolar overjet is the frontodorsal
distance between the most anterior points of the upper and lower alveolar
arches, whereas the maxillary arch is measured from the left tragus to the
right tragus via the subnasal point, and the mandibular arch is measured fr
om the left to the right tragus via the pogonion point. The growth of the m
andible in 7 Pierre Robin patients was found to be proportionately similar
to that observed in healthy control subjects age 0 months (N = 100), 6 mont
hs (N = 42), and 1 year (N = 32).