What characterizes Pierre Robin sequence along with micrognathia?

Pierre Robin sequence is characterized primarily by the presence of three key features: micrognathia (a small jaw), glossoptosis (a retracted or posteriorly positioned tongue), and often a cleft palate. While micrognathia is one of the defining traits, glossoptosis is crucial because it significantly impacts airway management and feeding in affected individuals.

Glossoptosis leads to the tongue obstructing the airway due to the small jaw, which can cause breathing difficulties, especially in newborns. As such, it is closely associated with the other features of the sequence. Addressing glossoptosis, along with micrognathia, is vital in the management of Pierre Robin sequence, particularly in ensuring that infants can breathe and feed adequately.

Other conditions such as craniosynostosis, maxillary hypoplasia, and cleft palate are related to various craniofacial abnormalities, but they do not distinctly define Pierre Robin sequence in the same way that micrognathia and glossoptosis do. Cleft palate may occur in conjunction with Pierre Robin sequence but is not a necessary feature for the diagnosis. Thus, the presence of glossoptosis alongside micrognathia is what specifically characterizes Pierre Robin sequence.