Four subtypes have been described: #Anatomic obstruction within the proximal cartilaginous eustachian tube. #Dilatory<unk> : Functional, dynamic (muscle failure), or anatomical obstruction of the Eustachian tube #Baro-challenge induced<unk> :<unk>  which generally features a normal otoscopy and normal tympanometry #Patulous<unk>
Eustachian tube dysfunction
Patulous Eustachian tube
Velopharyngeal insufficiency
Laryngotracheal stenosis
Laryngomalacia
Nasal septum deviation
Adventitial cystic disease
Laryngo-onycho-cutaneous syndrome