Loss of lamina dura and ground glass appearance indicates:
The periphery of fibrous dysplasia lesions most commonly is ill defined, with a gradual blending of normal trabecular bone into an abnormal trabecular pattern. Occasionally, the boundary between normal bone and the lesion can appear sharp and even corticated, especially in young lesions. The abnormal trabeculae usually are shorter, thinner, irregularly shaped, and more numerous than normal trabeculae. This creates a radiopaque pattern that can vary; it may have a granular appearance (or ground-glass appearance, resembling the small fragments of a shattered windshield), a pattern resembling the surface of an orange (peau d’orange), a wispy arrangement (cotton wool), or an amorphous, dense pattern. A distinctive characteristic is the organization of  the abnormal trabeculae into a swirling pattern similar to a fingerprint. Occasionally, radiolucent regions resembling cysts may occur in mature lesions of fibrous dysplasia. These are bone cavities that are analogous to simple bone cysts and occur more commonly  in mandibular lesions. If the fibrous dysplasia increases the bone density, the periodontal ligament space may appear to be very narrow. Fibrous dysplasia can displace teeth or interfere with normal eruption, complicating orthodontic therapy. In rare cases, some root resorption may occur. Involved teeth may have hypercementosis. Fibrous dysplasia appears to be unique in its ability to displace the inferior alveolar nerve canal in a superior direction.
Reference: White and Pharoah's Oral Radiology Principles and Interpretation 7th edition page no 407
Paget's disease
Fibrous dysplasia
Caffey's disease
Osteomalacia