Reactive osteocartilaginous metaplasia in denture wearers: a rare trauma-related lesion.

Objective: To present a case of reactive osteocartilaginous metaplasia (ROCM) in the anterior edentulous mandibular ridge.

Background: The ROCM secondary to chronic mechanical denture trauma is rare and appears as a focal sometimes painful mass on or near the crest of the edentulous alveolar ridge in long-term denture wearers. The literature review disclosed 24 cases involving more commonly the posterior portion of the mandible.

Unusual odontogenic keratocyst of the maxillary sinus.

An odontogenic keratocyst that eroded into the sinus through the maxillary bone and occupied it, showed replacement of the sinus respiratory epithelium by lesional epithelium, and was associated with fungal rhinosinusitis is presented. A review of the literature disclosed that epithelial replacement has been described in 2 previous case reports, although there is no report on the coexistence of odontogenic keratocyst with fungal rhinosinusitis.

Parathyroid hormone-related peptide (PTHrP), parathyroid hormone/parathyroid hormone-related peptide receptor 1 (PTHR1), and MSX1 protein are expressed in central and peripheral giant cell granulomas of the jaws.

Objective: Parathyroid hormone-related peptide (PTHrP) binds to the parathyroid hormone receptor type 1 (PTHR1), which results in the activation of pathways in osteoblasts that promote osteoclastogenesis through the RANK/RANKL system. RANK/RANKL expression has been shown in central giant cell granuloma of the jaws but PTHrP/PTHR1 has not. MSX1 protein is a classical transcription regulator which promotes cell proliferation and inhibits cell differentiation by inhibiting master genes in tissues such as bone and muscle.