Age-dependent development of the interincisive suture: a CT-based study on prevalence and dimensions

The interincisive suture (sutura interincisiva) connects the left and right premaxilla at the midline of the anterior palate and plays a role in craniofacial development. Despite its anatomical and developmental importance, postnatal changes in this suture remain understudied. Here, we investigated the age-dependent growth and closure of the interincisive suture using CT scans from 384 patients aged 0-94 years. Suture presence, length, and width were assessed in five-year age groups. Results show a progressive closure of the suture with age, with complete obliteration in most individuals over 35. Rates of open interincisive sutures in older patients are up to 25%. Sex differences emerged, with females showing a higher rate of suture closure in early years but a higher rate of open sutures in old age. A strong negative correlation was observed between age and both suture width (r = -0.545, p < 0.001) and length (r = -0.530, p < 0.001). The findings highlight similarities with, but also distinctions from, other midfacial sutures such as the midpalate suture and the incisive suture. Clinical implications include timing considerations for orthodontic interventions and improved understanding of midfacial growth patterns.