Mario Capogreco

Effect of c-Met Expression on Survival in Head and Neck Squamous Cell Carcinoma

The proto-oncogene c-Met has been suggested to be associated with progression of squamous cell carcinoma of the head and neck. The aims of the present study were to assess the prevalence of c-Met expression in oral squamous cell carcinoma (OSCC) and to verify whether c-Met can be considered a marker of prognosis in these patients. In a retrospective study, a cohort of 84 OSCC patients was investigated for c-Met expression and its cellular localization by immunohistochemistry. After grouping for c-Met expression, OSCC patients were statistically analyzed for the variables age, gender, histological grading, tumor node metastasis, staging and overall survival rate. Univariate and multivariate statistics were used for data analysis. Sixty-nine cases (82.2%) of OSCC showed immunopositivity, with a mainly membranous expression and scattered areas also showing a cytoplasmic localization, whereas 15 cases (17.8%) did not show c-Met. No statistical association was found between c-Met expression and any variables considered at baseline, apart from the higher number of c-Met positivity in females (p = 0.026). Among positive tumors, well-differentiated areas showed low or absent cytoplasmic expression, while low-differentiated areas showed both membranous and cytoplasmic positivity. In terms of prognostic significance, c-Met expression was found to have an independent association with a poorer overall survival rate (p = 0.036). On the basis of these results, it is possible to suggest c-Met as an early marker of poor prognosis, a hallmark of aggressive biological behavior in OSCC, suggested to be useful in identifying cases of OSCC before the relapse.

Genetics of syndromic and nonsyndromic cleft lip and palate.

Cleft of the lip with or without cleft palate (CL/P) represents one of the commonest congenital malformations in Western countries. Based on their association with specific malformative patterns or their presence as isolated defects, CL/P can be classified as syndromic and nonsyndromic, respectively. Both forms of CL/P are characterized by a strong genetic component. Syndromic forms are in many cases due to chromosomal aberrations or monogenic diseases. Among these, the Van der Woude syndrome, caused by mutation of the IRF6 gene, represents the commonest form of syndromic CL/P, accounting for about 2% of all cases. On the other hand, nonsyndromic CL/P is a multifactorial disease derived by the interaction between genetic and environmental factors. In recent years, great efforts have been made to identify the genes involved in the susceptibility to nonsyndromic CL/P and to disclose their relationship with specific environmental risk factors, to get information about the pathogenic mechanism leading to the malformation. In this article, we will review the most recent findings about the genes involved in the pathogenesis of syndromic and nonsyndromic CL/P, to provide information about the opportunity in the future to use specific genetic testing for the identification of at-risk mothers and the prevention of the disease based on a personalized approach.

Bcl-2 as prognostic factor in head and neck squamous cell carcinoma.

A series of 66 cases of oral squamous cell carcinoma (OSCC) was retrospectively analyzed by immunohisto-chemistry for bcl-2 expression to verify its predictive value for clinical outcome in patients with OSCC. After grouping for bcl-2 expression, OSCCs were statistically analyzed for the variables age, gender, histological grading (G), TNM, staging, recurrence, and overall survival rate. Univariate and multivariate (Cox regression) analyses were performed. Thirty-six OSCC (54.5%) showed expression for bcl-2, whereas 30 (44.5%) were negative. No statistical association was found between bcl-2 expression and any variables considered at baseline. Overall disease-specific survival rate at 72 months was 51%, independently from the extent of the tumor. In terms of prognostic significance, the bcl-2-positive group showed more than 60% survival at 72 months whereas the bcl-2-negative group showed none. An independent association of bcl-2 expression was found with an improved overall survival rate (p = 0.048), although grading and staging were established to be the best baseline markers of prognosis. On the basis of these results, it is possible to suggest bcl-2 as an early marker of prognosis: lack of bcl-2 expression could constitute a hallmark of aggressive biological behavior in OSCC.

Immediate Occlusal Loading of One-Piece Zirconia Implants: Five-Year Radiographic and Clinical Evaluation.

PURPOSE To evaluate radiographic and clinical outcomes of immediate occlusally loaded one-piece zirconia implants after 5 years of follow-up. MATERIALS AND METHODS This longitudinal clinical investigation included patients older than 18 years, in need of implant-supported single-unit dental rehabilitations. One-piece zirconia in healed and postextraction sites and immediately restored with provisional crowns in light occlusal contact. Definitive zirconia-ceramic restorations were delivered 3 to 4 months after surgery. Primary estimated outcomes were implant survival and success. Periapical radiographs were taken at implant insertion (T0), after 1 year (T1), and after 5 years (T2) to assess marginal bone loss (MBL). Probing depth (PD), modified Bleeding Index (mBI), modified Plaque Index (mPI), and gingival recession (REC) were also measured repeatedly for implants and reference teeth. Changes in parameters over time were assessed using the Wilcoxon signed rank test. In addition, multilevel mixed effects linear and logistic regression models were fitted to take into account within-subject correlations and baseline values. RESULTS Thirty-two implants were inserted in postextraction and healed sites (n = 16 of each) in 17 patients. One immediate implant was lost after 3 months, and one patient with one implant dropped out after T1. Therefore, the cumulative survival rates were 96.9% at T1 and 96.8% at T2 (4.3 to 6 years). No significant differences were observed in mean MBL between immediate and delayed implants at either T1 or T2. Moreover, different baseline parameters (sex, arch, implant location, smoking habits, grafting) did not show any influence on MBL at either time. In general, for all clinical parameters (PD, mBI, mPI, REC), implants seemed to perform similar to if not better than natural teeth. CONCLUSION Radiographic and clinical evaluations after 5 years showed satisfactory amounts of MBL and acceptable soft tissue health.

Association of Visual Defects and Occlusal Molar Class in Children

Purpose The purpose of this cross-sectional study is to evaluate the presence of any correlations between dysfunctions related to visual impairments and dental occlusion. Methods The test group included 34 subjects (21 males and 13 females; mean age 11 ± 2 years) randomly selected with the following inclusion criteria: absence of any diagnosis for problems at visual level except those related to refractive defects, visual acuity of at least 1.0, absence of any syndrome or malformation in the craniofacial area, good general health, and absence of any systemic disease able to influence the vision or the craniofacial growth. They underwent visual clinical tests to evaluate the presence of fusional vergence defects and amplitude. Each patient underwent an orthodontic clinical exam and the occlusal molar relationship of each subject was recorded and considered as occlusal variable. A statistical analysis with Chi-Squared test was performed in order to analyze the associations between the visual defects and the occlusal variable. Results A statistically significant association between the molar occlusal relationship and the occurrence of exodeviations was observed. The percentage of subjects presenting fusional amplitudes with convergence lower of the cut-off value was statistically significantly higher in the group of occlusal molar second class. Conclusions The results obtained show that there is an association between occlusal second molar class and fusional vergence defects.

Presentation of a keratocystic odontogenic tumor with agenesis: a case report

IntroductionWe analyzed the etiopathogenetic, clinical, radiographic, and histopathologic aspects of keratocystic odontogenic tumors, particularly in association with dental anomalies of number, with the aim of providing useful information for their correct diagnosis, treatment, and prognosis within a multidisciplinary approach.Case presentationA 14-year-old Caucasian girl presented for observation of bilateral agenesis of the upper incisors, which was diagnosed by orthopantomography. Approximately one year after starting orthodontic treatment, the patient went to the emergency department because of a phlegmonous tumefaction of the lateroposterior upper left maxillary region. Diagnostic orthopantomography and axial computed tomography scan results of the facial skeleton revealed a large lesion occupying the left maxillary sinus, rhizolysis of dental elements 26 and 27, and dislocation of dental element 28. The lesion and infected sinus mucosa were removed through surgical antral-cystectomy with the Caldwell-Luc approach. Histological examination of the lesion confirmed the suspected diagnosis of keratocystic odontogenic tumor. The 12-month follow-up orthopantomography and computed tomography scan results showed good trabecular bone formation in the lesion area. The 24-month follow-up results showed optimal healing in the area of the lesion, positive pulp vitality tests for teeth 26 and 27, and good periodontal tissue healing, as verified through periodontal probing.ConclusionsCombined with our observations from a careful review of the literature, the results of the case study suggest that keratocystic odontogenic tumor and dental agenesis probably do not develop through a common genetic cause. More likely, they are caused by related environmental factors. Management of this case required the multidisciplinary collaboration of different specializations and careful planning to devise a correct therapeutic protocol and reach a favorable prognosis.

Canal shaping of different single-file systems in curved root canals

Background/Purpose This study compared maintenance of canal anatomy, occurrence of apical transportation, and working time observed after instrumentation with One Shape New Generation rotary system (Micro-Mega), with those observed after instrumentation with Reciproc (VDW) and WaveOne (Dentsply-Maillefer) reciprocating systems. Materials and methods The mesial canals of 45 mandibular molars (curvature angles between 35° and 45°) were selected. Specimens were randomly divided into three groups, and canal preparations were performed using One Shape, Reciproc, or WaveOne systems (size #25). A digital double radiographic technique was used to determine apical transportation and change in angle of curvature. Also, working time and instrument failures were recorded. Data were statistically analyzed. Results During preparation, no file fractured. No statistically significant differences were found among groups. No system showed a significantly faster preparation time than others (P > 0.05). All instruments maintained the original canal curvature well and were safe to use. Conclusion Both continuous rotary instrument and reciprocating systems did not have any influence on the presence of apical transportation or caused an alteration in angle of canal curvature.

Dental students' knowledge of medication-related osteonecrosis of the jaw

Objectives: The aim of this study was to evaluate and assess knowledge and attitude of dental students about medication-related osteonecrosis of the jaw (MRONJ), to optimize future training programs in this field. Materials and Methods: A cross-sectional study was administrated. Ninety-eight participants agreed to complete an anonymous questionnaire. It was divided into two sections: the first section was about general information such as interviewers gender and date of birth; the second section included questions about bisphosphonates (BPs), others medication associated to osteonecrosis of the jaw (ONJ), risk factors, and prevention of osteonecrosis. Descriptive statistics were computed and the odds ratio was used to compare the odds for the groups. Results: Ninety-nine percent of participants declared to know BPs, but only 26.9% of 4th year and 34.8% of 6th year students knew the correct definition of MRONJ. Almost all of students identified the importance to report, in anamnesis, the use of BPs, as well as to check-up patients before the beginning of treatment; on the other hand, the knowledge about how invasive dental treatment might be carried out in patients under therapy was not adequate. In addition, half of the students did not recognize any active principle or commercial name of BPs. The situation was even worse regarding alternative drugs involved in ONJ. Conclusions: These findings are alarming and the lack of knowledge about MRONJ suggests that greater educational efforts should be performed about this pathology at undergraduate level.

Effect of Airborne Particle Abrasion on Microtensile Bond Strength of Total-Etch Adhesives to Human Dentin

Aim of this study was to investigate a specific airborne particle abrasion pretreatment on dentin and its effects on microtensile bond strengths of four commercial total-etch adhesives. Midcoronal occlusal dentin of extracted human molars was used. Teeth were randomly assigned to 4 groups according to the adhesive system used: OptiBond FL (FL), OptiBond Solo Plus (SO), Prime & Bond (PB), and Riva Bond LC (RB). Specimens from each group were further divided into two subgroups: control specimens were treated with adhesive procedures; abraded specimens were pretreated with airborne particle abrasion using 50 μm Al2O3 before adhesion. After bonding procedures, composite crowns were incrementally built up. Specimens were sectioned perpendicular to adhesive interface to produce multiple beams, which were tested under tension until failure. Data were statistically analysed. Failure mode analysis was performed. Overall comparison showed significant increase in bond strength (p < 0.001) between abraded and no-abraded specimens, independently of brand. Intrabrand comparison showed statistical increase when abraded specimens were tested compared to no-abraded ones, with the exception of PB that did not show such difference. Distribution of failure mode was relatively uniform among all subgroups. Surface treatment by airborne particle abrasion with Al2O3 particles can increase the bond strength of total-etch adhesives.

Orthodontic brackets removal: morphological in vitro evaluation

Debonding procedure is a fundamental stage in the orthodontic treatment (1). Adhesive removal should lead to a complete polished enamel in order to prevent the plaque accumulation and enamel injures (2). Aim of this study is to evaluate in vitro by use of Scanning Electron Microscopy (SEM) the enamel surface after the bracket removal and the enamel polishing with four different techniques. Two groups of teeth, group A (n=12) and group B (n=12) were evaluated. The images were analyzed by the Image J software. After the debonding procedure the two groups were subcategorized in four groups (1A, 1B, 2A, 2B 3A, 3B and 4A, 4B, n.=3). The discriminant between the two main categories was the use of a magnification system (Group A) during the polishing stages. From the qualitative and quantitative images analysis the most conservative technique resulted to be the use of tungsten carbide bur, followed by the final polishing using the soft-polisher tip for composites. In group A, the percentage of the residual adhesive resulted 8% and the damages on the enamel surface showed to be 7%. In group B the percentage of the residual adhesive resulted 35% and the damages on the enamel surface showed to be 15%. This analysis showed how the use of a magnification system aids in significant way during the debonding procedures in the enamel surfaces’ preservation.The authors are grateful to Dr. M. Gianmatteo and to Dr. E. Nazaj, University of L’Aquila, for their help in the sampling and microscopy procedures.