Identification of critical windows in early development of human upper respiratory tract and middle ear disease

Area of Science:

• Developmental anatomy
• Pediatric otology
• Craniofacial growth

Background:

• Otitis media (OM), a common pediatric ear infection, is linked to the development of the cartilaginous Eustachian tube (CET).
• Understanding the growth patterns of the CET and the dilator tubae (DT) muscle is crucial for identifying factors contributing to OM.

Purpose of the Study:

• To reconstruct the morphology of the CET and DT in a developmental series of human crania.
• To investigate the timing and directionality of CET and upper respiratory tract (URT) growth.
• To correlate observed morphological changes with the incidence of pediatric otitis media.

Main Methods:

• Utilized a developmental series of dry crania, divided into seven growth stages based on dental eruption.
• Employed traditional and 3D geometric morphometrics (GM) to analyze bony landmarks.
• Calculated CET and DT morphology using bony endpoints.

Main Results:

• Significant shape differences in CET and DT morphology were observed between newborns, early infants, and older individuals.
• The most substantial growth changes occurred between birth and 6 months.
• Incongruent growth rates between the CET and DT from 6 to 12 months may impair Eustachian tube function, potentially contributing to OM.

Conclusions:

• Disparities in CET and DT growth during infancy may increase susceptibility to otitis media.
• Maturation of both CET and DT morphology after the first year correlates with a decrease in reported ear infections.
• This study provides anatomical insights into the developmental basis of pediatric otitis media.