A histometrical analysis of age changes in the human lingual artery

The lingual arteries from 450 Japanese autopsies, ranging in age from 3 months to 106 years, were carefully selected for examination of the ageing process. Histopathologically, a focal intimal thickening, considered to be an intimal cushion rather than an atheromatous lesion, was observed in cases as young as 6-month-old infants. The most frequent intimal change was diffuse fibrous thickening, present throughout the life span. Luminal obstruction caused by extensive atheromatous plaques was never seen. The internal elastic lamina regressed with increasing age. Histometrically, the radius of the artery increased not only during the developmental period but also after maturation, with a modified exponential curve. The thickness of the media also increased with a modified exponential curve until the third decade, when it became fairly constant. The thickness of the intima increased exponentially throughout the life span. The value of the relative luminal radius, considered to be an index value for arterial senescence, remained constant until the seventh decade and then showed a distinct decrease. This luminal narrowing, resulting primarily from intimal thickening, was compensated for by outward growth of the media and remodelling of the internal elastic lamina with increasing age until the seventh decade. The changes in the dimensions of both media and intima, and the histopathological alterations in the lingual arterial wall with progressing age, suggest that disturbances of homeostasis in the media play an important role in age-related progression of arteriosclerotic change.