2004 Volume 16 Issue 3 Pages 205-212
Murine brachymorphism (bm) has cartilage with glycosaminoglycans (GAGs) undersulfated. The phenotype is inherited as an autosomal recessive. Anterior transverse crossbite sometimes spontaneously occurs in BALB/c-bm/bm mouse (bm homozygotes) inbred. Temporomandibular joints of BALB/c-bm/bm mouse were histologically and biochemically evaluated.
We used BALB/c mice (control), BALB/c-bm/bm mice with normal occlusion (bm-Norm), and BALB/c-bm/bm mice with crossbite (bm-Mal). Coronal sections of control and bm-Norm groups aged 8 weeks were made and stained with hematoxylin-eosin, with the methods of alcian blue critical electrolyte concentration, and with sensitized high iron diamine methods after treatment of testicular hyaluronidase (bovine testis). After extracting condylar cartilage of control, bm-Norm, and bm-Mal groups aged 3 weeks and 13 weeks, sulfated GAGs were also measured using demethylmethylene blue assay.
Compared with the control group, condylar cartilage of the bm-Norm group was thinner and had an unclear zone of hypertrophic cells. Keratan sulfate and chondroitin sulfate were weakly stained in the bm-Norm group. The concentration of sulfated GAGs in cartilage of condyle in each group aged 13 weeks was lower than that in each group aged 3 weeks. The concentration of sulfated GAGs in cartilage of condyle in the bm-Norm and bm-Mal groups aged 3 weeks was lower than that in the control group. The concentration of sulfated GAGs in cartilage of condyle in the bm-Mal group aged 13 weeks was significantly lower than those in the control group and bm-Norm group. There was no significant difference between the concentration of sulfated GAGs in TMJ of mandibular shift sides and that in TMJ of non-shift sides of the bm-Mal group.
