It is not known whether cells derived from stem cells retain their differentiation and morpho-functional properties after long-term cryopreservation. This information is of importance to evaluate their potential for long-term storage with a view to subsequent use in therapy. Here, we describe the morpho-functional properties of dental pulp stem cells (SBP-DPSCs), and of their differentiated osteoblasts, recovered after long-term cryopreservation. After storage for 2 years, we found that stem cells are still capable of differentiation, and that their differentiated cytotypes proliferate and produce woven bone tissue. In addition, cells still express all their respective surface antigens, confirming cellular integrity. In particular, SBP-DPSCs differentiated into pre-osteoblasts, showing diffuse positivity for ALP, BAP, RUNX-2, and calcein. Recovered osteoblasts expressed bone-specific markers and were easily recognizable ultrastructurally, with no alterations observed at this level. In addition, after in vivo transplantation, woven bone converted into a 3D lamellar bone type. Therefore, dental pulp stem cells and their osteoblast-derived cells can be long-term cryopreserved and may prove to be attractive for clinical applications.

To harvest bone for autologous grafting is a daily problem encountered by craniofacial and oral surgeons. Stem cells derived from human dental pulp are able to differentiate in osteoblasts and are a potential source of autologous bone produced in vitro. The authors describe their preliminary results in this new field with its potential application in craniomaxillofacial surgery. Dental pulp was gently extracted from 34 human permanent teeth (all third molars) of patients 19 to 37 years of age. After they were digested, the cells were selected using a cytometer for c-kit, STRO-1, CD34, CD45, and then for CD44 and RUNX-2. This study, made on a considerable number of cases, provided evidence that dental pulp is extremely rich in stem cells, which were c-kit+/CD34+/STRO-1+/CD45-, capable of differentiation toward several stromal-derived differentiated cells and mainly osteoblasts. These findings, supported by the large number of cases, are of great interest for tissue regeneration, tissue-based clinical therapies, and transplantation.

This article includes a comprehensive and up-to-date review on the cysts of the oral cavity. Several classifications of odontogenic (OC) and non-odontogenic (non-OC) oral cysts and the surrounding regions have been proposed. We suggest a new critical classification based on an established relationship between anatomical area, histological origin and clinical behavior (frequency, rate of recurrence, malignant potential). Moreover, the differential cytokeratin (CKs) expression of the various cysts is reported as epithelium-specific markers of differential diagnosis. Finally, issues related to differential diagnosis and therapeutic approaches of the cysts included in the two groups are described.

Fibrous histiocytoma is a benign soft tissue tumour arising as a fibrous mass everywhere in the human body. The involvement of the oral cavity is rare. We report two cases of benign fibrous histiocytoma that localized in the oral cavity. The clinical and histological features of the lesion are reported. Finally, a literature revision of this pathology at the level of the oral cavity is reported.

The surgical removal of impacted lower third molar is an ordinary intervention. The treatment of choice in this pathology is an intraoral or, seldom, extraoral surgical approach. Various surgical procedures have been described to remove ectopic mandibular teeth. The more common technique is an intraoral approach (so named "conservative"), even when the tooth is located in an ectopic area. However, the "intraoral approach" is often related with the difficulty of view, the bleeding of the surgical site, and with the possible lesions of inferior alveolar or lingual nerve. From the other side, a nonconservative surgical approach like "extraoral pathway" may be associated with no aesthetic cutaneous postoperative scar tissue. The aim of those 2 study cases is to highlight the management of infected ectopic third molars located close to the lower border of the mandibular body, underlining the anatomical land markers of the submandibular area. The authors have applied the extraoral pathway using an incision of small size. From our analysis, the treatment of those typical can be managed by using a "mini-skin-incision" (so termed as mini-submandibular approach) respecting the cosmetic expectations of the patients.