The influence of senescence on craniofacial and cervical morphology in humans

Abstract

This study discusses the morphologic evolution of the cranio-facial and cervical bone structures throughout life. A cephalometric study was made on lateral radiographs. The population studied included 84 males and 102 females. Ages ranged from 21 to 101. The cranial structures, superior facial structure, mandible and cervical vertebral column were successively examined. The anteroposterior diameter of the calvarium does not seem to undergo any modification during life. On the other hand, a highly significant increase of the thickness of this structure can be noted. The upper facial structure presents some modification, namely a significant increase of its posterior height. The palatine processus seems to change direction and pivot downwards and forwards. The maxillary sinus does not undergo any changes. The mandible, which is stable in its major axes, shows more malleable sectors which are more especially situated at the level of its body. The study of the cervical vertebral column reveals a loss of overall height, and an increase in the lordosis. The most numerous and most evident morphologic modifications were observed around the age of fifty in both males and females. The fact that these transformations are always commoned and greater in the latter reveals the plausible influence of the menopause. It appears that bone structures of membranous origin are the site of significant modifications compared with structures of endochondral origin, which benefit from a greater stability.

The influence of age, sex, population group, and dentition on the mandibular angle as measured on a South African sample

“…Although senescence has a general effect on the skeleton and specifically on the morphology of the mandible (Doual et al 1997), the size of the mandibular angle in our adult sample did not change with age per se. This is in agreement with the findings of some other researchers (e.g., Keen, 1945;Israel, 1973) although there is no general consensus in the literature on this matter.…”

“…Most of the previous metrical studies on the mandibular angle have been done on radiographs (Israel, 1973;Doual et al, 1997;Ohm and Silness, 1999;Xie and Ainamo, 2004;Merrot et al, 2005). Ruff (1980) demonstrated that increases in the gonial angle with age are underestimated on lateral radiographs if bigonial breadth also increases.…”

Regional shape change in adult facial bone curvature with age

“…Increases in craniofacial dimensions such as facial height, mandibular length, bizygomatic and bigonial breadth, and head circumference, length, and breadth have been detected with advancing age (e.g., Pfitzner, 1899;Hellman, 1927;Hrdlička, 1936; Hooten and Dupertuis, 1951;Thompson and Kendrick, 1964;Forsberg, 1979;Ruff, 1980;Behrents, 1985;Forsberg et al, 1991;Bartlett et al, 1992;Bishara et al, 1994;West and McNamara, 1999;Akgü l and Toygar, 2002). Cranial (Humphrey, 1858;Todd, 1924; Israel, 1973a, b;Behrents, 1985;Doual et al, 1997) and mandibular cortical bone thickness (Israel, 1969;Lestrel et al, 1980) have also been found to increase with age. Furthermore, contourrelated studies of the orbits and maxilla suggest these regions undergo age-related differential enlargement (Zadoo and Pessa, 2000;Pessa and Chen, 2002;Shaw and Kahn, 2007).…”

Neuromuscular dentistry: Occlusal diseases and posture

“…42 In these studies age was not considered as a confounding factor, but the fact is that with age lordosis increases. 54 It was hypothesized that jaw posture may influence muscles and cause postural adaptations at spine level. Unilateral cross-bite has been investigated as a risk factor for asymmetric jaw growth and unbalanced muscle activity.…”