Pycnodysostosis: review and case report

AIM

Aim of the present study was to present a case report of a patient suffering from pycnodysostosis and assess how it may manifest and affect the dental/ orthodontic treatment.

METHODS

An 11-year-old patient who was diagnosed with pycnodysostosis at the age of 18 months, attended the orthodontics department requiring treatment for extensive carious lesions, periodontal disease and severe crowding.

RESULTS

After an accurate radiographic, clinical and orthodontic assessment of the patient taking into consideration the severity of the condition and the patient's necessities, we have formulated a treatment plan, which was accepted by both the patient and parents. We took into consideration the risks and benefits of the options available and the requests of the patient.

CONCLUSION

We have decided to opt for the extraction of teeth to relieve the crowding as this was impeding good oral hygiene and hence increasing the risk of caries and periodontal disease. Such patients must be placed under an oral hygiene prevention scheme, a treatment plan must be accurately designed and the patient must be constantly motivated.

Aesthetic restoration of upper lip after removal of post-trauma foreign body (orthodontic bracket)

AIM

Approach to dental trauma should always be based on a careful examination of the traumatised area, including both hard and soft tissues, to ascertain the presence of a foreign body and to assess the best treatment and follow-up. In this work a case of an orthodontic bracket migrated to the upper lip and retained there for 10 years, following a trauma is discussed.

CASE REPORT

The patient complained symptomatic swelling of the upper lip; palpation and x-rays showed the presence of a foreign body, identified as an orthodontic bracket. Medical history revealed that patient had a dental trauma 10 years prior. The foreign body was localised and removed. At the two week follow-up visit after surgical incision of the lip, signs and symptoms (i.e. the swollen lip) were resolved. This case emphasises the importance of accurate management of the traumatic event, through proper diagnosis and therapy of both hard and soft tissues, even if the examination if the patient is performed years after the dental trauma.

Cancer cell reprogramming: stem cell differentiation stage factors and an agent based model to optimize cancer treatment

The recent tumor research has lead scientists to recognize the central role played by cancer stem cells in sustaining malignancy and chemo-resistance. A model of cancer presented by one of us describes the mechanisms that give rise to the different kinds of cancer stem-like cells and the role of these cells in cancer diseases. The model implies a shift in the conceptualization of the disease from reductionism to complexity theory. By exploiting the link between the agent-based simulation technique and the theory of complexity, the medical view is here translated into a corresponding computational model. Two main categories of agents characterize the model, 1) cancer stem-like cells and 2) stem cell differentiation stage factors. Cancer cells agents are then distinguished based on the differentiation stage associated with the malignancy. Differentiation factors interact with cancer cells and then, with varying degrees of fitness, induce differentiation or cause apoptosis. The model inputs are then fitted to experimental data and numerical simulations carried out. By performing virtual experiments on the model's choice variables a decision-maker (physician) can obtains insights on the progression of the disease and on the effects of a choice of administration frequency and or dose. The model also paves the way to future research, whose perspectives are discussed.

Use of endosseous one-piece yttrium-stabilized zirconia dental implants in premolar region: a two-year clinical preliminary report

AIM

The aim of this work was to clinically and radiographically evaluate survival and success rate of zirconia dental implants positioned in premolar area during a follow-up period of at least 12 months up to 24 months.

METHODS

Sixteen patients were treated with 26 zirconia implants. All implants received immediate temporary restorations and 6 months after surgery were definitively restored. Twelve to 14 months after implant insertion, a clinical-radiographical evaluation was performed in order to estimate peri-implant tissues health and peri-implant marginal bone loss.

RESULTS

The survival rate was 96.16%. The success rate was 91.6%.

CONCLUSION

Because of the limited number of implants, conclusions may not be considered significant even if results are encouraging. Further scientific information regarding clinical use of zirconia dental implants are needed, as well as prospective long-term clinical studies in order to understand if zirconia implants may represent a valid alternative to titanium implants.

TGF-beta1 and VEGF after fresh frozen bone allograft insertion in oral-maxillo-facial surgery

Bone regeneration technique using allografts is widely used in oral surgery to repair alveolar defects and to increase alveolar volume for endosseous implant insertions. Bone allografts promote the reabsorption and neo-synthesis of bone tissue, which are regulated by numerous cytokines, proteins and growth factors. In this study, six patients with insufficient alveolar volume for endosseous implant insertions, were treated with bone regeneration technique using Fresh Frozen Bone (FFB) allografts collected from the femoral head or the hip. Samples of bone graft collected during graft insertion surgery and biopsies collected six months later during implantology were fixed, decalcified and analyzed histomorphologically and morphometrically by haematoxylin-eosin staining. In addition, TGF-beta1 and VEGF were analyzed by immunohistochemistry. The histological analysis of FFBs showed wide areas of calcified bone organized in osteons intermingled with areas of non-calcified matrix containing osteoblasts. However, the regenerated alveolar bone, collected six months after the graft insertion surgery, showed wide areas of non-calcified matrix. TGF-beta1 and VEGF were less expressed in FFB than in regenerated alveolar bone.

Displacement of a dental implant into the maxillary sinus: case series

Dental implants placed in the maxilla risk failure because of the low density of the maxillary bone and the shortness of the maxillary ridge. Moreover, inadequate implant preparation, drilling or installation can easily lead to complications related to the maxillary sinuses. Displacement of dental implants into the maxillary sinus can cause serious complications, but there are few reports of such cases. The aim of this paper is to present three cases of a migrated dental implants into the maxillary sinus: in the first two cases the dental implant was found close to the medial wall of the maxillary sinus and was removed through a surgical approach, whereas in the third case the dental implant was spontaneously expelled from the nasal cavities through the mucociliary clearance. The most frequent adverse effect is the local infection of tissue around the implant. For this reason, implants placed close to the maxillary sinus offer a route for infection from the oral cavity to the sinus. While in some cases implant migration causes sinusitis in other, the patients remain asymptomatic; anyway, the treatment depends on the symptoms of maxillary sinusitis. In the third case the dental implant was spontaneously expelled from the nasal graves. Our report illustrates that a powerful mechanism of mucociliary action can cause relatively heavy objects within the maxillary sinus to migrate naturally to the sinus ostia against gravitational force and then to be expelled from the nasal cavities.

The eps8 family of proteins links growth factor stimulation to actin reorganization generating functional redundancy in the Ras/Rac pathway

Sos-1, a guanine nucleotide exchange factor (GEF), eps8 and Abi1, two signaling proteins, and the lipid kinase phosphoinositide 3-kinase (PI3-K), assemble in a multimolecular complex required for Rac activation leading to actin cytoskeletal remodeling. Consistently, eps8 -/- fibroblasts fail to form membrane ruffles in response to growth factor stimulation. Surprisingly, eps8 null mice are healthy, fertile, and display no overt phenotype, suggesting the existence of functional redundancy within this pathway. Here, we describe the identification and characterization of a family of eps8-related proteins, comprising three novel gene products, named eps8L1, eps8L2, and eps8L3. Eps8Ls display collinear topology and 27-42% identity to eps8. Similarly to eps8, eps8Ls interact with Abi1 and Sos-1; however, only eps8L1 and eps8L2 activate the Rac-GEF activity of Sos-1, and bind to actin in vivo. Consistently, eps8L1 and eps8L2, but not eps8L3, localize to PDGF-induced, F-actin-rich ruffles and restore receptor tyrosine kinase (RTK)-mediated actin remodeling when expressed in eps8 -/- fibroblasts. Thus, the eps8Ls define a novel family of proteins responsible for functional redundancy in the RTK-activated signaling pathway leading to actin remodeling. Finally, the patterns of expression of eps8 and eps8L2 in mice are remarkably overlapping, thus providing a likely explanation for the lack of overt phenotype in eps8 null mice.