Cholesteatoma Severely Impacts the Integrity and Bone Material Quality of the Incus.

Cholesteatoma can lead to progressive destruction of the auditory ossicles along with conductive hearing loss but precise data on the microstructural, cellular, and compositional aspects of affected ossicles are not available. Here, we obtained incus specimens from patients who had cholesteatoma with conductive hearing loss. Incudes were evaluated by micro-computed tomography, histomorphometry on undecalcified sections, quantitative backscattered electron imaging, and nanoindentation.

Prevention of Hypomineralization In Auditory Ossicles of Vitamin D Receptor (Vdr) Deficient Mice.

Intact mineralization of the auditory ossicles - the smallest bones in the body - is essential for sound transmission in the middle ear, while ossicular hypomineralization is associated with conductive hearing loss. Here, we performed a high-resolution analysis of the ossicles in vitamin D receptor deficient mice ( ), which are characterized by hypocalcemia and skeletal mineralization defects, and investigated whether local hypomineralization can be prevented by feeding a calcium-rich rescue diet ( ). In mice fed a regular diet ( ), quantitative backscattered electron imaging (qBEI) revealed an increased void volume (porosity, p<0.

Conductive Hearing Loss in the Hyp Mouse Model of X-Linked Hypophosphatemia Is Accompanied by Hypomineralization of the Auditory Ossicles.

X-linked hypophosphatemia (XLH) is a hereditary musculoskeletal disorder caused by loss-of-function mutations in the PHEX gene. In XLH, increased circulating fibroblast growth factor 23 (FGF23) levels cause renal phosphate wasting and low concentrations of 1,25-dihydroxyvitamin D, leading to an early clinical manifestation of rickets. Importantly, hearing loss is commonly observed in XLH patients.