Morphometric characterization of the very young child mandibular growth pattern: What happen before and after the deciduous dentition development?

Abstract

Objectives: Numerous tools have been developed to characterize the morphometry of 3D models. The aim of this study was to apply these techniques to better understand the morphometric growth pattern of healthy children's mandibles. Material and Methods:The study sample was composed of 480 very young children aged from 36 gestational weeks to 7 years old. The sample was divided into three subsamples according to the development stages of their deciduous dentition. Several biometric data were collected on 3D mandibular models.Results: There was homothetic growth during the first years of life. Once all deciduous teeth were fully erupted, the mandibular corpus warped more independently of the ramus, and the inter-individual variability was more pronounced. Throughout the growth period, several subgroups could be identified, highlighting the morphological growth pattern of the mandible. Conclusions:A particular morphogenesis of the mandible during the growth period was observed, which was correlated with deciduous dentition development. In younger individuals, this morphological pattern was mainly characterized by the progressive closure of the chin symphysis and ramus growth. The tongue movements in the oral space, depending on whether the child was bottle-or breast-fed, may explain this result. As the children grew older, the mandible widened to create sufficient space for the developing teeth buds. During the eruption of deciduous dentition, the mandible took on various morphologies, which was likely based on the child's sex and diet. Therefore, we assume that this mandibular morphogenesis is induced by the functional strains affecting the mandible during deciduous teeth development. K E Y W O R D Sdeciduous dentition development,

Developmental features and predicting airway failure risk in critically ill children with mandibular hypoplasia using 3D computational tomographic analysis

“…Healthy control participants were age, sex, height, and weight-matched to those with mandibular hypoplasia. The morphological growth pattern of the mandible is strongly related to the dentition development stages 11 ; hence, subgroup analyses were conducted according to the stage of dentition (≤ 5 and > 5 year-old group) 12 .…”

“…To investigate the risk factors for a difficult airway, the area under the receiver-operating characteristic (ROC) curve of ∆ parameter was generated. As age and sex could play an important role in mandibular development 11 , logistic regression, adjusted for age and sex, was used to assess the association between upper airway measurements and difficult airway status. A P < 0.05 was considered statistically significant.…”

The Hypoplasic Mandible: What Makes it Different From the Healthy Child?

“…To complete the study sample, a paired sample of sex-and age-matched healthy children was also analyzed. These data were collected from the database of a previous paper focusing on the mandibular growth pattern in healthy children (Remy et al, 2019). These patients did not show any traumatic injury or pathology affecting their mandibular morphology or growth.…”

“…Based on a previously published protocol (Remy et al, 2018;Remy et al, 2019), 10 landmarks were collected to spot structures on 3D mandibular models with Avizo software 7.1.0 (see Table 1).…”

“…However, these methods only highlight differences in the 2D mandibular dimensions. Yet, considering the homothetic growth of the mandible during the first years of life (Remy et al, 2019), it can be assumed that mandibular hypoplasia affects the mandible shape in its 3 dimensions: both mandibular body length, ramus height, and arch width could be size reduced. Recent studies have investigated these differences with the analysis of 3D mandibular models, by comparing linear and angular measurements between pathological and healthy patients (Chung et al, 2012;Cohen et al, 2017;Kim et al, 2018).…”