Fig. 4

Photomicrographs from the control group showing fibrous connective tissue in the defect area without bone marrow formation (yellow rectangle), old bone region (white rectangle) (a, H & E stain 4×), and extensive fibrocartilage (b, H & E stain 40×). Photomicrographs from the hydroxyapatite group, showing trabecular bone formation (c, H & E stain 10×) and woven bone (d, H & E stain 40×). Photomicrographs from the coral group showing trabecular-pattern bone formation in grafted area (black rectangle) and grafted area with old bone and marrow (white rectangle) (e, H & E stain 4×). Note the trabecular bone and chondroplasia zone in the coral group (f, H & E stain 4×)