These altered developmental trajectories appear to be driven by a range of influences including defects in cartilage growth, neuromuscular function and fetal constraint.
Defects in the growth of the mandible sit at the core of PRS and the natural history of PRS can be classified into two major streams: primary defects of mandibular outgrowth and elongation and issues that are external to the mandibular skeleton but that secondarily impact on its growth. The diagnosis of PRS depends on readily recognizable clinical features but the phenotypic similarity of many PRS individuals conceals considerable etiological heterogeneity. These feeding and respiratory complications frequently continue well into childhood, affecting not only growth and development but also impacting on long term educational attainment. The respiratory issues require careful management and in severe cases may require extended stays in neonatal intensive care units and surgical intervention such as lengthening the lower jaw or tracheotomy to relieve airway obstruction. Pierre Robin sequence (PRS) is a craniofacial anomaly comprising mandibular hypoplasia, cleft secondary palate and glossoptosis leading to life-threatening obstructive apnea and feeding difficulties during the neonatal period. Pierre Robin in 1923 is credited as being the first to describe Robin sequence: a small jaw, leading to a tongue that falls back in the throat and upper.