Perinatal vulnerability: its impact on oral and craniofacial hard tissue development.

Advances in perinatal and neonatal medicine have dramatically improved the survival rates of infants with perinatal vulnerabilities of preterm birth (PTB), low birth weight (LBW) or small for gestational age (SGA), by rescuing these infants from immediate postnatal complications. Despite improved survival from such problems, it has in turn highlighted long-term complications, including psychiatric, neurological, respiratory, cardiovascular and metabolic diseases. In the oral and craniofacial regions, perinatal vulnerability is associated with an increased risk of developmental complications, including bone deformities, malocclusion and tooth malformations. These anomalies are often tangible and can be recognized earlier than extracranial sequelae; thus, they may serve as accessible indicators for predicting extracranial sequelae that remain latent. Oral and craniofacial sequelae are considered consequences of changes in nutritional status and oxygen saturation before and after birth, which are related to epigenetic changes. Additionally, the development of oral and craniofacial tissues is controlled by mechanical forces. The underlying mechanisms have not been fully elucidated, and future studies elucidating these mechanisms will enhance diagnostic and therapeutic strategies, as well as prognostic accuracy, ultimately improving long-term outcomes for infants born with perinatal vulnerabilities.