Title: Chin - Wikipedia
Headings: Chin
Chin
Contents
Evolution
Functional perspectives
Developmental perspectives
Other perspectives
Cleft chin
Double chin
See also
References

Content: Moreover, Daegling (1993) explains the chin as a functional adaptation to resist masticatory stress that causes vertical bending stresses in the coronal plane. Others have argued that the prominent chin is adapted to resisting wishboning forces, dorso-ventral shear forces, and generally a mechanical advantage to resist lateral transverse bending and vertical bending in the coronal plane. On the contrary, others have suggested that the presence of the chin is not related to mastication. The presence of thick bone in the relatively small mandible may indicate better force resistance capacity. However, the question stands of whether the chin is an adaptive or nonadaptive structure. Developmental perspectives
Recent works on the morphological changes of the mandible during development have shown that the human chin, or at least the inverted-T shaped mental region, develops during the prenatal period, but the chin does not become prominent until the early postnatal period. This later modification happens by bone remodeling processes ( bone resorption and bone deposition ). Coquerelle et al. show that the anteriorly positioned cervical column of the spine and forward displacement of the hyoid bone limit the anterior–posterior breadth in the oral cavity for the tongue, laryngeal, and suprahyoid musculatures. Accordingly, this leads the upper parts of the mandible ( alveolar process) to retract posteriorly, following the posterior movement of the upper tooth row, while the lower part of the symphysis remained protruded to create more space, thereby creating the inverted-T shaped mental relief during early ages and the prominent chin later.