The surface topography of the articular surfaces of the guinea-pig mandibular joint

Abstract

The fibrous articular surfaces of the mandibular joints of 35 guinea pigs with an age range of 0–8 yr were irregular when examined in the non-loaded state. Discrete, occasionally complex, surface irregularities, perhaps the expression of superficial underlying cells, were observed on all the surfaces examined by reflected light (RLM), reflected light interference (RLIM) and scanning electron microscopy (SEM). Discrete surface irregularities were identified by RLIM as elevations with a mean maximum diameter of 13.6 μm and a mean minimum diameter of 10.8 μm. The frequency of these elevations decreased with increasing specimen age. Early ageing of the tissues appeared to be associated with the loss of interfibrillar matrix and the exposure of superficial fibre bundles. Fibrillated areas appeared grossly disordered and devoid of the raised irregularities. Surface structure varied with the preparative technique used before SEM. Dehydration through ethanol to propylene oxide and vacuum drying was the least disruptive of the four techniques assessed.