Nondestructive, Epi‐Illumination Surface Microscopic Characterization of Surface Discontinuity in Bone: A New Approach Offers a Descriptive Vocabulary and New Insights

Abstract

Perspectives are in the eye of the beholder and are expanded with increased scrutiny (e.g., magnification). The term "porosity' for macroscopically or radiologically identifiable discontinuity in bone is so variably applied as to be incomprehensible in its meanings. A closer examination of surface discontinuity seems appropriate. Histological and atomic level analysis of bone alterations misses the forest for the trees and the former destroys the very subject it attempts to characterize. Surface discontinuity was therefore evaluated at the three-dimensional submacroscopic level. An epifluorescent/illumination microscope was used to characterize surface discontinuity in intact specimens of known pathophysiology and/or derivation. The derived perspectives were then utilized to characterize other surface discontinuity. The smooth boundaries of vascular foramen and internal bifurcation, continuity of the expanded base of nerve structures and surrounding elevated rings of Sharpey fibers are all clearly distinguishable from fronts of resorption in erosive arthritis, serpentine discontinuity associated with infectious processes, specific zones of resorption noted in tuberculosis, and structural bone exposure by taphonomic abrasion. These perspectives allow the bone pathology associated with hematoma to be characterized as accentuated Sharpey fiber insertions; maxillary and sphenoid surface discontinuity, as vascular in origin; and periosteal reaction, as manifest by superficial bifurcating channels and in-growth, similar to healing trephanation. Epi-illumination microscopy bridges macroscopic and histological examination, providing greater understanding of the pathology, at no cost to the integrity of the material studied. It explains a number of observed results, while providing discriminatory descriptions of phenomena for which pathophysiology has not yet been clarified. Anat Rec, 296:580-589,

Apparent sixth sense in theropod evolution: The making of a Cretaceous weathervane

“…The opposing edges of the groove are in the same two-dimensional plane, in contrast to folds which are non-planar. The lateral line correlates were recognized on the basis of pits containing multiple well-defined, circular and elliptical spaces with sub-surface expansions [ 42 ]. Penetrating vascular channels were recognized on the basis of smooth boundaries and internal bifurcation [ 42 ].…”

“…The lateral line correlates were recognized on the basis of pits containing multiple well-defined, circular and elliptical spaces with sub-surface expansions [ 42 ]. Penetrating vascular channels were recognized on the basis of smooth boundaries and internal bifurcation [ 42 ]. The groove and dentary perforations in Jane were compared to those noted in Amia calva and Atractosteus spatula .…”

“…The lateral line in fish, as characterized in Amia calva and Atractosteus spatula , is recognized as a series of grooves [lateral line canals] traversing the surface of the mandible and upper skull [ 42 ]. Within the grooves are pits containing multiple well-defined, circular and elliptical spaces with sub-surface expansions [ 42 ]. These appear to represent a “housing” for the cupula, the jelly-like sheath encapsulating a cluster of sensory and support cells [ 39 ].…”

“…These appear to represent a “housing” for the cupula, the jelly-like sheath encapsulating a cluster of sensory and support cells [ 39 ]. Interest in the role of dentary foramen [ 43 ], speculation as to presence of a dermal sensory system in other Mesozoic reptiles [ 44 , 45 ], characterization of the microscopic appearance of the lateral line in fish [ 42 ], and recognition of a previously undescribed, but similar structure in the dentary of albertosaurines [ 46 ] stimulated this report.…”

In search of consensus: Terminology for entheseal changes (EC)

“…Depressions and other mineralized tissue loss of the surface (Rothschild, 2013). In fibrous entheses, cortical surface discontinuity can also involve the trabecular bone.…”