Evaluation of the presence of the premaxillary-maxillary suture in growing patients: A retrospective CBCT study.

Background: The premaxillary-maxillary suture (PMS) is related to midface development, but its exact closure period remains undefined. Some authors consider the premaxilla as an independent bone with potential for orthopaedic stimulation, while others see it as a phylogenetic vestige.

Objective: To determine the prevalence of the premaxillary-maxillary suture (PMS) in cone beam computed tomography (CBCT) images of patients aged 6 to 16years, according to age and sex, treated at the Dental Clinic of the Pontificia Universidad Católica de Chile's Oral Imaging Service between 2015 and 2023.

Material and methods: CBCT images from 511 subjects were analysed. The presence or absence of the PMS was evaluated in the oblique axial slice. Descriptive statistics of the sample were performed, followed by logistic regression models to assess the relationship between the presence of the PMS and age and sex variables, with a significance level of 5%.

Results: Of the total sample (511 subjects), only 190 cases presented a visible PMS in CBCT images (37.18%), with 104 females and 86 males. When analysing the relationship with sex, no statistically significant association was found (P=0.090, OR=0.72). However, a statistically significant association with age was observed (P<0.001, OR=0.75).

Conclusion: The prevalence of the PMS in this study was 37.18%, significantly associated with age. The probability of observing the PMS in CBCT images decreases by 25% for each additional year of age. This suggests that PMS is more likely to be observed at younger ages and may be a factor to consider for anterior maxillary advancement in patients with maxillary retrusion. Further studies are needed to evaluate the degree of suture fusion to determine if it can be effectively stimulated by orthopaedic appliances.