The investigators hypothesize that a functional computational model that simulates the mechanical and aerodynamic behavior of the upper airway in children with Pierre Robin Sequence (PRS) and laryngeal lesions (e.g. subglottic stenosis or SGS) can be used as an effective diagnostic and treatment planning tool.

Inclusion Criteria:

1. Micrognathia, Suspected or Diagnosis of PRS, defined (Gorlin) as:

   micrognathia (mandibular hypoplasia), cleft palate and airway obstruction, and/or

   Diagnosis of SGS defined (Bluestone) as:

   • subglottic airway diameter of 4 mm or less in a term neonate;
   • subglottic airway diameter of 3.5 mm or less in a premature neonate;
   • inability to pass an endotracheal tube of expected size for age

2. Informed consent by parent or legal guardian

3. Age < 18 years at enrollment

4. Scheduled for clinically indicated endoscopic upper airway evaluation

5. Ability to comply with study visits and study procedures as judged by the site investigator

Inclusion criterion also included for Specific Aim 2 (Longitudinal):

Subjects must be scheduled for an operative procedure to correct or bypass upper airway obstruction (i.e. mandibular distraction, endoscopic airway surgery, laryngotracheoplasty, cricotracheal resection, or tracheostomy) OR recently (within past 4 weeks) diagnosed as having an anomaly not currently requiring surgical management.

Exclusion Criteria:

1. Acute, intercurrent respiratory infection, defined as an increase from baseline in cough, wheezing, or respiratory rate with onset in the preceding week.
2. Physical findings at screening that would compromise the safety of the participant or the quality of the study (i.e. fever, increased respiratory rate above baseline, significant acute emesis, or alteration in baseline neurologic status).
3. For research CT scans any sedation risk, such as Bronchopulmonary Dysplasia (BPD) with upper airway obstruction, residual oxygen requirement, and an unsecured airway.

Control data will be collected from clinically indicated neck or maxillofacial CT imaging data that include the entire airway with no noted airway obstructions or airway abnormalities.

Children < 18 years of age with a diagnosis of either Pierre Robin Sequence, Micrognathia or Subglottic Stenosis.

Clinically indicated control data will be collected from CT scans of neck and maxillofacial CT scans performed on children < 18 years of age