Characterizing mandibular growth using three-dimensional imaging techniques and anatomic landmarks

Abstract

Objective To provide quantitative data on the multi-planar growth of the mandible, this study derived accurate linear and angular mandible measurements using landmarks on three dimensional (3D) mandible models. This novel method was used to quantify 3D mandibular growth and characterize the emergence of sexual dimorphism. Design Cross-sectional and longitudinal imaging data were obtained from a retrospective computed tomography (CT) database for 51 typically developing individuals between the ages of one and nineteen years. The software Analyze was used to generate 104 3DCT mandible models. Eleven landmarks placed on the models defined six linear measurements (lateral condyle, gonion, and endomolare width, ramus and mental depth, and mandible length) and three angular measurements (gonion, gnathion, and lingual). A fourth degree polynomial fit quantified growth trends, its derivative quantified growth rates, and a composite growth model determined growth types (neural/cranial and somatic/skeletal). Sex differences were assessed in four age cohorts, each spanning five years, to determine the ontogenetic pattern producing sexual dimorphism of the adult mandible. Results Mandibular growth trends and growth rates were non-uniform. In general, structures in the horizontal plane displayed predominantly neural/cranial growth types, whereas structures in the vertical plane had somatic/skeletal growth types. Significant prepubertal sex differences in the inferior aspect of the mandible dissipated when growth in males began to outpace that of females at eight to ten years of age, but sexual dimorphism re-emerged during and after puberty. Conclusions This 3D analysis of mandibular growth provides preliminary normative developmental data for clinical assessment and craniofacial growth studies.

Online Statistical Inference for Large-Scale Binary Images

“…The dark red regions show positive growth (bone deposition) and dark blue regions show negative growth (bone resorption). The findings are consistent with previous studies based on 2D surface deformation [5] and landmarks [10]. …”

Sensitivity and Specificity of Cephalometric Measures for the Diagnosis of Sagittal Skeletal Malocclusion

“…In our study, ANB angle was greater (5.75°) for the diagnosis of class II than what was previously reported (3.6°), suggesting a more posterior mandible position in younger children [23]. It has been reported that during puberty, the mandible experiences a pubertal growth spurt that can modify facial and sagittal skeletal relationship [11,16,32,33].…”

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

“…Our study sample was homogeneous and more exhaustive than most previous studies, both in terms of the number of individuals included and of the age period studied (Hutchinson et al, ; Kelly et al, ; Smartt et al, ). Furthermore, the subdivision of the total study sample in subsamples according to the number of teeth apparent on the 3D models helped us to better correlate the highlighted morphological development of the mandible with the deciduous dentition development.…”

“…To present more reliable results, other authors proposed to characterize the mandible growth pattern with the definition of anatomical landmarks from which distances were computed (Hutchinson, L'Abbé, & Oettlé, ; Kelly et al, ). With these approaches, only the modification of the mandible dimensions was investigated.…”