Study reveals early mandibular catch-up growth in infants with Robin sequence

Robin sequence is characterized by micrognathia, glossoptosis, and often cleft palate, leading to airway obstruction and feeding challenges. Treatment strategies vary widely, ranging from conservative interventions like prone positioning and specialized feeding therapy to surgical approaches such as mandibular distraction. However, whether early treatment influences long-term jaw growth remains debated, partly due to limited longitudinal data in infancy and the difficulty of obtaining repeated radiologic imaging in young patients. Additionally, past assessments largely relied on manual or subjective measurements that could not fully characterize facial profile development over time. Due to these challenges, there is a need to conduct objective, longitudinal studies to clarify early mandibular growth patterns and evaluate treatment outcomes.

Researchers from Tuebingen University Hospital conducted a prospective cohort study published (DOI: 10.1007/s12519-024-00797-z) on April 5, 2024 in the World Journal of Pediatrics. The team collected repeated 3D facial images from infants with isolated Robin sequence treated using a conservative functional therapy protocol, and compared them to healthy infants over the first year of life. The study focused on two objective measures derived from soft-tissue images that indicate jaw size and positioning, capturing how facial relationships changed with age.

A total of 19 infants with Robin sequence and 32 healthy controls were enrolled. Using standardized 3D imaging, the researchers measured two key craniofacial parameters: the digital jaw index (JI), reflecting relative upper-to-lower jaw size, and the A'-Nasion'-B' (ANB') soft-tissue angle, indicating the spatial relationship between the maxilla and mandible. Both parameters were tracked repeatedly across the first year of life. Data analysis showed that while infants with Robin sequence initially exhibited markedly larger jaw disproportions compared to healthy infants, both groups demonstrated steady decreases in JI and ANB' over time. Importantly, the interaction between diagnosis and age for the ANB' parameter indicated that infants with Robin sequence exhibited measurable mandibular catch-up growth during early development. This suggests that functional conservative therapy—which promotes forward tongue posture, improved orofacial muscle activity, and oral feeding stimulation—may stimulate adaptive mandibular changes. The findings provide objective, longitudinal evidence supporting functional treatment strategies as a promising non-surgical option in early Robin sequence care.

The researchers emphasize that their non-invasive imaging-based approach represents an important advancement in the early evaluation of craniofacial development. They highlight that using soft-tissue-based digital measurements avoids the ethical concerns associated with repeated radiation exposure in infants. The team notes that their findings reinforce the concept that functional therapy may promote natural mandibular adaptation and should be considered in early care planning for Robin sequence.

These results offer valuable clinical guidance for healthcare teams treating infants with Robin sequence. By demonstrating measurable catch-up growth in the mandible during the first year of life under conservative therapy, the study supports non-surgical approaches as effective first-line options. The imaging protocol and measurement techniques developed here also create a standardized framework for future comparative studies across treatment centers and surgical programs. In the future, similar longitudinal imaging could be used to tailor treatment decisions, evaluate therapy effectiveness, and potentially reduce the need for invasive interventions in selected infants.