New perspectives in the differential diagnosis of jaw lesions: Machine learning and inflammatory biomarkers.

This study aimed to assess the diagnostic performance of a machine learning approach that utilized radiomic features extracted from Cone Beam Computer Tomography (CBCT) images and inflammatory biomarkers for distinguishing between Dentigerous Cysts (DCs), Odontogenic Keratocysts (OKCs), and Unicystic Ameloblastomas (UAs). This retrospective study involves 103 patients who underwent jaw lesion surgery in the Maxillofacial Surgery Unit of Federico II University Of Naples between January 2018 and January 2023. Nonparametric Wilcoxon-Mann-Whitney and Kruskal Wallis tests were used for continuous variables. Linear and non-logistic regression models (LRM and NLRM) were employed, along with machine learning techniques such as decision tree (DT), k-nearest neighbor (KNN), and support vector machine (SVM), to predict the outcomes. When individual inflammatory biomarkers were considered alone, their ability to differentiate between OKCs, UAs, and DCs was below 50 % accuracy. However, a linear regression model combining four inflammatory biomarkers achieved an accuracy of 95 % and an AUC of 0.96. The accuracy of single radiomics predictors was lower than that of inflammatory biomarkers, with an AUC of 0.83. The Fine Tree model, utilizing NLR, SII, and one radiomic feature, achieved an accuracy of 94.3 % (AUC = 0.95) on the training and testing sets, and a validation set accuracy of 100 %. The Fine Tree model demonstrated the capability to discriminate between OKCs, UAs, and DCs. However, the LRM utilizing four inflammatory biomarkers proved to be the most effective algorithm for distinguishing between OKCs, UAs, and DCs.

Fresh Frozen Homologous Rib Cartilage: A Narrative Review of a New Trend in Rhinoplasty.

Background: Revision rhinoplasty is a technically demanding surgical procedure that can put every surgeon in trouble. The main issue of these cases is often an altered osteocartilaginous framework following over-resection during the first intervention. Moreover, the available septal or auricular cartilage for grafting is usually not enough. This review aims to examine contemporary advances in applications of fresh frozen cartilage in rhinoplasty. Methods: A structured review of the current literature (up to December 2023) was performed on four bibliographic databases: PubMed, EMBASE, Cochrane and Medline. The search terms were combinations of "Rhinoplasty" and "Cartilage Graft", "Allograft" or "Fresh Frozen Cartilage". The citations of selected studies and review articles were also evaluated if present. Results: The research resulted in 152 articles, and only ten met the inclusion criteria: nine clinical articles and one in vitro study. One of the ten eligible articles was excluded. Conclusions: Fresh frozen rib cartilage proved to be a viable alternative to autologous rib grafts and irradiated homologous rib graft. Despite the higher costs, FFRG can provide a sufficient amount of tissue for grafting avoiding donor site complications and reducing the operative time and proved to have more chondrocytes and to be less prone to resorption compared to irradiated rib.

Epidemiological analysis of patients with isolated blowout fractures of orbital floor: Correlation between demographic characteristics and fracture area.

Isolated orbital floor fractures are more frequent due to low bone thickness (2 mm). The aim of this study was to conduct a retrospective epidemiological analysis on these fractures, investigating demographic variables and fractures' features and their statistical correlation. A total of 120 patients with isolated orbital floor fracture, admitted at the Maxillofacial Surgery Unit of University of Naples Federico II, from 2010 to 2022 were enrolled in the study. Patients were evaluated for age, sex, smoke, comorbidities, post-traumatic clinical manifestation,s and defect side and size. Statistical analysis was conducted using the Pearson regression coefficient (r). The fractures were more frequent in men (male:female 2.2:1) because of road accidents (30% of cases). The average age was 48 years. Enophthalmos, diplopia and ocular motility anomalies were observed in 31%, 23% and 21% of cases, respectively. Statistical analysis revealed that age was related to fracture area; in particular, older patients showed larger fractures (p < 0.001). Interpersonal violence and traffic accidents were related to younger age (p < 0.001). Data analysis revealed that isolated orbital floor fractures are more frequent in young men (<40 years) because of road accidents or interpersonal violence. There is a statistical correlation between fracture area and patient age; in particular, older age corresponds to larger defects.

Depth of reading within the gingival sulcus of seven intraoral scanners: an in vitro study.

AIM: The present in vitro study aimed to evaluate the depth of reading of intraoral scanners (IOSs) within the gingival sulcus. MATERIALS AND METHODS: A knife-edge preparation for a full crown was performed on a Frasaco model. The gingival sulcus of the scanned model was modified using a dedicated software program (Model Creator, exocad DentalCAD 2.4 Plovdiv) by setting the apical width (AW), coronal width (CW), and gingival sulcus depth (D). Two dental models with different gingival sulcus depths (1 or 2 mm) were printed using the digital light processing (DLP) technique. Each model was scanned 10 times. Seven different IOSs were used: Emerald, Trios 3, Carestream 3600, Dental Wings DWIO, CondorScan, True Definition Scanner (TDS), and Cerec Omnicam. Measurements of D values were performed using 3Shape 3D viewer software. The normality of the data distribution was evaluated using the Shapiro-Wilk test (P < 0.05). The nonparametric Levene's test was used to check for homoscedasticity. The data were statistically analyzed using the Kruskal-Wallis test (α = 0.05) and the Nemenyi test. RESULTS: All IOSs were able to read within the 1-mm-deep gingival sulcus, albeit with some statistically significant differences (P < 0.001). TDS and Trios 3 were able to read within the 2-mm-deep gingival sulcus (P < 0.001). CONCLUSIONS: The depth of reading of different IOSs can vary significantly. In the model with a 2-mm gingival sulcus, even in the absence of oral fluids, the depth of reading was incomplete, suggesting that deep preparations into the gingival sulcus are difficult to detect with IOSs.

Submental intubation in complex maxillofacial trauma: Pilot balloon protection.

AIMS: This study aims to describe our refined technique of submental intubation to avoid the recorded intraoperative complications related to tube passage and pilot balloon rupture. CASE SERIES: This is a retrospective case series of 21 patients with complex maxillofacial trauma who underwent submental intubation from January 2019 to January 2023. All the patients underwent to the same procedure with a new technique of pilot balloon protection: the pilot balloon was not deflated because, once the connector was removed, only the tube was curved and passed through the incision extraorally while the cuff remained inflated. The wire of the pilot balloon was passed behind the last tooth so as not to interfere with the maxillary-mandibular fixation, remaining extraorally under the anesthetist's view. DISCUSSION: Only 2 patients (9.5%) reported complications related to submental intubation: in particular a patient (4.8%) reported oral floor infection, and in another patient (4.8%) an unesthetic skin scar was observed. No patients reported intraoperative complications related to the procedure. CONCLUSION: The technique of pilot balloon protection that we have proposed seems to be effective in reducing the intraoperative complications related to the passage of the pilot balloon, such as rupture, damage or early extubation.

Surgical management and side effects of parotid gland surgery for benign lesions: a retrospective analysis of our experience from 2012 to 2021.

Surgery is the treatment of choice for tumours in the parotid gland. We evaluated complications following parotid surgery. We conducted a retrospective study on 554 patients undergoing parotid surgery for benign parotid tumours from 2012 to 2021. We analysed complication rates between extracapsular dissection (ECD) and superficial parotidectomy (SP). We found 19 capsular ruptures in patients undergoing ECD (5.34%) and five among those undergoing SP (2.52%) [p < 0,05]; 16 cases of temporary facial paralysis among those undergoing ECD (4.49%) and 35 in patients undergoing SP (17.67%) [p < 0,05]; and eight instances of permanent facial nerve paralysis in patients undergoing ECD (2.25%) [p > 0,05] and 13 in patients undergoing SP (6.56%). Among the mid-term complications described were: 22 salivary fistulas among patients operated with ECD (6.18%) [p > 0,05] and 17 in patients with SP (8.58%) 17 sialoceles in those who underwent ECD (4.77%) and seven with SP (3.53%) [p > 0,05]. Regarding late complications, we found: surgical wound dehiscence, pathological scarring (keloid), Frey's syndrome, and recurrence, which affected 45 patients with ECD (12.64%) and 21 with SP for dehiscence (10.6%) [p < 0,05]; 28 keloids in patients with ECD (7.86%) and 15 in patients with SP (7.57%) [p > 0,05]; 12 cases of Frey's syndrome in patients with ECD (3.37%) and 36 with SP (18.18%) [p < 0,05]; and finally 22 recurrences in patients who underwent ECD (6.18%) and 13 in patients who underwent SP (6.56%) [p > 0,05], including 30 in the 273 patients with pleomorphic adenoma and five in the 214 patients with Warthin's tumour. We can conclude that the onset of the different complications after parotid gland surgery are related to the surgery performed. Our data confirm that there is a tight relationship between type of surgery performed and type of complication.

Minimally Invasive Harvesting Technique for Costal Cartilage Graft: Donor Site, Morbidity and Aesthetic Outcomes.

Cartilage grafts are well-known as being reliable in reconstructive surgery for craniofacial pathologies. The aim of this study is to describe a new technique which requires an incision smaller than 1.5 cm but is still effective for harvesting cartilage graft. Thirty-six patients who underwent costal cartilage harvesting for septorhinoplasty have been included in this study, admitted from January 2018 to December 2021. Out of 36 patients, 34 have not reported any major complications, and two cases were followed up for pneumothorax. There were no infections and no chest wall deformities. All patients reported minimal pain at the donor site. The Vancouver Scar Scale was used to evaluate the entity of the postoperative scarring phenomena. This scale total ranges from 0 (representing normal skin) to a maximum score of 13 (representing worst scar imaginable). The results were 1.53 SD ± 0.64 (on average) 1 week after the surgical procedure and 1.28 SD ± 0.45 (on average) at the 6 months follow-up. This minimally invasive method provided a valid and effective surgical technique for cartilage graft. Despite the limitations of the case series, it seems that this procedure might be comparable to other and well-established traditional procedures and could be even preferred when the minimal invasiveness is mandatory.

Support Tools in the Differential Diagnosis of Salivary Gland Tumors through Inflammatory Biomarkers and Radiomics Metrics: A Preliminary Study.

BACKGROUND: The purpose of this study was to investigate how the systemic inflammation response index (SIRI), systemic immune-inflammation index (SII), neutrophil/lymphocyte ratio (NLR) and platelet/lymphocyte ratio (PLR), and radiomic metrics (quantitative descriptors of image content) extracted from MRI sequences by machine learning increase the efficacy of proper presurgical differentiation between benign and malignant salivary gland tumors. METHODS: A retrospective study of 117 patients with salivary gland tumors was conducted between January 2015 and November 2022. Univariate analyses with nonparametric tests and multivariate analyses with machine learning approaches were used. RESULTS: Inflammatory biomarkers showed statistically significant differences (p < 0.05) in the Kruskal-Wallis test based on median values in discriminating Warthin tumors from pleomorphic adenoma and malignancies. The accuracy of NLR, PLR, SII, and SIRI was 0.88, 0.74, 0.76, and 0.83, respectively. Analysis of radiomic metrics to discriminate Warthin tumors from pleomorphic adenoma and malignancies showed statistically significant differences (p < 0.05) in nine radiomic features. The best multivariate analysis result was obtained from an SVM model with 86% accuracy, 68% sensitivity, and 91% specificity for six features. CONCLUSIONS: Inflammatory biomarkers and radiomic features can comparably support a pre-surgical differential diagnosis.

Are YouTube Videos a Useful and Reliable Source of Information for Patients with Temporomandibular Joint Disorders?

Counseling is considered a first-line conservative therapy with respect to temporomandibular joint disorders (TMJD). Nowadays, 50 to 80% of patients acquire health information from the internet before turning to professionals. The purpose of this study has been to investigate the quality of information about TMJD that patients can obtain from YouTube. A YouTube.com search was conducted using the terms "temporomandibular joint disorder"; "limited movement of the mandible"; and "mandibular joint pain". The videos identified were assessed independently by two panels of three professional and lay reviewers with HONcode, modified DISCERN (MD) and the global quality scale (GQS). A total of 106 videos were included. The professional reviewers reported a mean HONcode score of 4.148 ± 1.314 and a mean MD score of 2.519 ± 1.267, testifying to a modest general quality of the videos. The mean GQS score was 2.987 ± 1.012 for the professional and 3.469 ± 0.891 for the lay reviewers (p < 0.001). The correlations between the ratings were significant between the reviewers within the same group but not between the two groups. The presence of animations significantly influenced the GQS score expressed by the lay reviewers (p = 0.011) but not that of the professionals (p = 0.640). The quality of the information on TMJD on YouTube is generally of poor quality. Healthcare systems and professionals should be prepared to correct misinformation and build trusting relationships with patients which are based on quality counseling. Similarly, academic institutions should produce quality content that leads patients with TMJD toward a correct diagnostic-therapeutic process.

Incidence of Orbital Side Effects in Zygomaticomaxillary Complex and Isolated Orbital Walls Fractures: A Retrospective Study in South Italy and a Brief Review of the Literature.

Zygomaticomaxillary complex and isolated orbital walls fractures are one of the most common fractures of the midface, often presenting orbital symptoms and complications. Our study was born with the aim of understanding the trend in the incidence of orbital presurgical symptoms, specifically diplopia, enophthalmos and exophthalmos, in the Campania Region in southern Italy. We conducted a retrospective, monocentric observational study at the Maxillofacial Surgery Unit of the Federico II University Hospital of Naples, enrolling 402 patients who reported a fracture of the zygomaticomaxillary complex and orbital floor region from 15 June 2021 to 15 June 2022. Patients were evaluated by age, gender, etiology, type of fracture, preoperative orbital side effects and symptoms. Pre-surgical side effects were studied, and 16% of patients (n = 66) developed diplopia. Diplopia was most common in patients previously operated on for orbital wall fractures (100%), and least common in patients who reported trauma after interpersonal violence (15%) and road traffic accidents (11%). Exophthalmos appeared only in 1% (six cases); whereas it did not appear in 99% (396 cases). Enophthalmos was present in 4% (sixteen cases), most commonly in interpersonal violence cases (two cases). The frequency of orbital complications in patients with zygomaticomaxillary complex and isolated orbital walls fractures suggests how diplopia remains the most common pre-surgical orbital side effect.

Facial soft tissue thickness measurement method and relationship with BMI, age and sex.

INTRODUCTION: Facial aesthetics results from the harmony of various components of the craniofacial region, a structure whose physiognomy and topography are determined by a set of hard and soft tissues. Few works in the literature have investigated the relationship between the variables of sex, age, BMI and soft tissue thickness and have considered how these variables may influence operative outcomes. The purpose of this study is to increase the pre-operative knowledge of the thickness of the soft tissues of the face through an analysis of their measurement conducted on cone beam computed tomography (CBCT) and to investigate the impact that the variables of gender, age and BMI have on their determination. MATERIALS AND METHODS: For this study 82 patients were recruited between January 2020 and January 2021 in the Department of Maxillofacial Surgery of the University of Naples "Federico II". A descriptive analysis of the sample was carried out on the selected sample, calculating averages and standard deviations for the individual variables analyzed. RESULTS: BMI has a predominant role on some craniometric points while age and sex have a more marginal role. Our analysis shows that some points are affected by only one variable, BMI (G' N' PR' ID' SM' GN' PG' MIO' ACP' GO' ZY' SC' IC' ECMS' and MMB'); some points are affected by both BMI and gender (MP' and MR'); while only two (RHI' and MSO') are influenced by all the three variables. CONCLUSION: A priori knowledge through CBCT of the thickness of the soft tissues of the face and a comparison with the data we propose could provide the surgeon with advance notice of the characteristics of the tissues which she/he will encounter.

Malpositioned Implant in the Esthetic Area: The Peri-Implant Plastic Surgery and Angulated Welded Abutment Approach.

PURPOSE: To describe the treatment of malpositioned implants in the esthetic area using the angulated welded abutment (AWA) approach together with peri-implant soft tissue surgery. MATERIALS AND METHODS: A clinical case with extreme buccal angulation of two implants in the anterior maxilla was used to illustrate the AWA technique. After implant impression-taking, digital analysis was used to determine the ideal prosthetic angulation of the abutment and the ideal position of its screw hole in relation to the gingival margin of the adjacent teeth. The AWA was designed in two combinable components that were meant to be welded together. Before the welding process, an angulated screw was included in the abutment. Since the angulated screw was inside the abutment, the screwdriver hole could be designed as narrow as possible and put in an ideal position. After periodontal and peri-implant surgery were carried out, the AWA was applied to the implants. RESULTS: The AWA allowed correction of the prosthetic axis. Moreover, relocation of the screw hole allowed the gingival tissue to creep over the abutment. In this way, a new esthetic restoration can be placed after the mucogingival surgery. CONCLUSION: The excessive misangulation of the implants was efficiently recovered. Further studies are needed to evaluate long-term clinical success, and standardization of this technique is required for routine clinical use. Int J Prosthodont 2023;36:228-232. doi: 10.11607/ijp.759.

Effect of Fluorographene Addition on Mechanical and Adhesive Properties of a New Core Build-Up Composite.

This study aims to develop a restorative material having such mechanical and adhesive properties that it can be used both as a reconstruction material and as a luting cement. The experimental core build-up composite (CBC) was derived from a self-adhesive cement by the modification of its chemical formula, requiring the use of dedicated dentin and ceramic primers. The adhesive properties to zirconia and dentin were analyzed with a micro-Shear Bond Strength test (mSBS). The mechanical properties were analyzed by a flexural strength test. The results were compared with those obtained for other commercially available cements and core build-up materials, both before and after addition of 2 wt.% fluorographene. The CBC obtained average values in the mSBS of 49.7 ± 4.74 MPa for zirconia and 32.2 ± 4.9 MPa for dentin, as well as values of 110.9 ± 9.3 MPa for flexural strength and 6170.8 ± 703.2 MPa for Young's modulus. The addition of fluorographene, while increasing the Young's modulus of the core build-up composite by 10%, did not improve the adhesive capabilities of the primers and cement on either zirconia or dentin. The CBC showed adhesive and mechanical properties adequate both for a restoration material and a luting cement. The addition of 2 wt.% fluorographene was shown to interfere with the polymerization reaction of the material, suggesting the need for further studies.

Three Different Types of Fat Grafting for Facial Systemic Sclerosis: A Case Series.

Systemic sclerosis (SSc) is a heterogeneous, chronic connective tissue disease, characterized by skin fibrosis as well as vascular and visceral lesions. It can involve the lungs, heart, kidneys, gastrointestinal tract, and bones. The orofacial manifestations of SSc can cause functional, aesthetic, and social distress, resulting in significant psychological implications for the patients. In recent decades, fat grafting improved the aesthetic outcomes in terms of volume deficiency, contour asymmetry, and skin elasticity of the face thanks to the regenerative action of the stem cells contained within it. We describe five cases of a patient with SSc treated with fat grafting used to correct volume loss and facial elasticity of the lips and perioral region on the middle and lower third of the face. All the patients received regular postoperative checks at weeks 1 and 2. A multiple choice questionnaire was administered to assess the degree of tolerability of the procedure. The reliability of the questionnaire was evaluated by calculating the Cronbach alpha using the MedCalc Statistical Software version 20.113. The aim of our study is to describe three different types of fat grafting used to correct volume loss and restore facial elasticity of the lips and perioral region on the middle and lower third of the face.

Radiomics Metrics Combined with Clinical Data in the Surgical Management of Early-Stage (cT1-T2 N0) Tongue Squamous Cell Carcinomas: A Preliminary Study.

Objective: To predict the risk of metastatic lymph nodes and the tumor grading related to oral tongue squamous cell carcinoma (OTSCC) through the combination of clinical data with radiomics metrics by computed tomography, and to develop a supportive approach in the management of the lymphatic cervical areas, with particular attention to the early stages (T1−T2). Between March 2016 and February 2020, patients with histologically confirmed OTSCC, treated by partial glossectomy and ipsilateral laterocervical lymphadenectomy and subjected to computed tomography (CT) before surgery, were identified by two centers: 81 patients (49 female and 32 male) with 58 years as the median age (range 19−86 years). Univariate analysis with non-parametric tests and multivariate analysis with machine learning approaches were used. Clinical, hematological parameters and radiological features extracted by CT were considered individually and in combination. All clinical parameters showed statistically significant differences (p < 0.05) for the Kruskal−Wallis test when discriminating both the tumor grading and the metastatic lymph nodes. DOI, PLR, SII, and SIRI showed an accuracy of 0.70 (ROC analysis) when identifying the tumor grading, while an accuracy ≥ 0.78 was shown by DOI, NLR, PLR, SII, and SIRI when discriminating metastatic lymph nodes. In the context of the analysis of radiomics metrics, the original_glszm_HighGrayLevelZoneEmphasis feature was selected for identifying the tumor grading (accuracy of 0.70), while the wavelet_HHH_glrlm_LowGrayLevelRunEmphasis predictor was selected for determining metastatic lymph nodes (accuracy of 0.96). Remarkable findings were also obtained when classifying patients with a machine learning approach. Radiomics features alone can predict tumor grading with an accuracy of 0.76 using a logistic regression model, while an accuracy of 0.82 can be obtained by running a CART algorithm through a combination of three clinical parameters (SIRI, DOI, and PLR) with a radiomics feature (wavelet_LLL_glszm_SizeZoneNonUniformityNormalized). In the context of predicting metastatic lymph nodes, an accuracy of 0.94 was obtained using 15 radiomics features in a logistic regression model, while both CART and CIDT achieved an asymptotic accuracy value of 1.00 using only one radiomics feature. Radiomics features and clinical parameters have an important role in identifying tumor grading and metastatic lymph nodes. Machine learning approaches can be used as an easy-to-use tool to stratify patients with early-stage OTSCC, based on the identification of metastatic and non-metastatic lymph nodes.

In vitro 2D and 3D roughness and spectrophotometric and gloss analyses of ceramic materials after polishing with different prophylactic pastes.

STATEMENT OF PROBLEM: The effect of prophylactic polishing pastes on composite resin materials has been extensively investigated, but little is known about their effect on ceramic materials. PURPOSE: The purpose of this in vitro study was to evaluate the effect of prophylactic polishing pastes on the 2D and 3D roughness, translucency, and gloss of different ceramic materials. MATERIAL AND METHODS: A total of 120 flat specimens (thickness: 2 mm) obtained from computer-aided design and computer-aided manufacturing (CAD-CAM) blocks of leucite glass-ceramic (Empress CAD), lithium disilicate glass-ceramic (e.max CAD), and zirconia (Zenostar MT) were glazed and sintered. Forty specimens from each material were then divided into 4 groups and polished with Cleanic fine, Nupro fine, or Proxyt fine pastes, leaving the control group untreated. The specimens were polished for 2 minutes with a prophylaxis cup mounted on a handpiece, applying a constant load of 3.9 N at 2000 rpm. Surface roughness was measured by using a contact profilometer and a 3D optical profilometer. The translucency parameter and gloss value were calculated by using a spectrophotometer and a glossmeter. One specimen per group was observed by scanning electron microscopy at ×200 magnification. Differences in means were compared by using 2-way ANOVA followed by the Tukey honestly significant difference (HSD) test (α=.05). RESULTS: The 2D roughness of Empress was lower than that of e.max (P<.05) and was increased by using Cleanic fine and Nupro fine pastes (P<.05). The translucency parameter values of Empress and Zenostar decreased with the use of Nupro fine paste (P<.05). Zenostar showed the lowest translucency (P<.05). The effect of prophylactic polishing pastes on gloss was minimal (P>.05). The gloss of Empress was higher than that of Zenostar and e.max (P<.05). The Pearson correlation showed that gloss and surface roughness were correlated (P<.001). CONCLUSIONS: Polishing procedures can alter the surface of a ceramic restoration.

A new surgical approach for the treatment of Rhinophyma.

BACKGROUND: Rhinophyma is a rare and benign pathological condition affecting the nose. It can be localized or generalized causing a nasal deformity, mainly of the lower 2/3 of the nose. Clinically, rhinophyma is characterized by the aberrant development of the vascularization of the skin of the nose. The nose becomes particularly sensitive, and even a minimal external trauma can cause bleeding. Different treatment methods have been described during the last few years, but surgery still remains the gold standard. The aim is to obtain a reduction of the abnormal tissue, by debulking and fine contouring followed by hemostasis and a very careful postoperative care. Herein we report one case of Rhinophyma treated with the Microdebrider (Storz®). CASE REPORT: A 70 year old male with a diagnosis of rhinophyma was admitted to the Department of Maxillo-Facial Surgery of "Federico II" University of Naples. The patient underwent a debridment of rhinophyma, combining dermabrasion and decortication, using a Microdebrider (Storz®). After the surgery, the wound was covered with an advanced dressing, a collagen sponge equina (Condress®) applied at the end of the procedure and routinely during the follow up control to promote the healing process. CONCLUSION: After 2 months the patient was completely healed without any complications and without any signs of recurrence, obtaining a good aesthetic and functional result. After 25 months of follow up the result is still stable. KEY WORDS: Rhinophyma, Microdebrider.

Nanostructured Zirconia-Based Ceramics and Composites in Dentistry: A State-of-the-Art Review.

The objective of this paper is to review the current knowledge on the development of nanostructured zirconia-based ceramics and composites suitable for application in dentistry. Isi Web of Science, Science Direct, Scientific.net databases, and Google were searched electronically for the period of 1980 to the present, matching the keywords "nano" with the keywords: "Zirconia, ZrO2, Y-TZP, and dental, dentistry". A total of 74 papers were found, with the majority coming from Asia, indicating a more active scientific interest on the topic in this geographic area, followed by Europe, South America, and North America. The research shows, even though the scientific activity on nanostructured ceramics was intense in the last fifteen years, the development of fully dense zirconia-based nanoceramics is yet at an initial stage, most of all from the point of view of the clinical applications. It has been demonstrated that nanostructured ceramics can show improved properties because of the reduction of the grain size to the nanoscale. This is also true for zirconia-based nanoceramics, where some improvements in mechanical, optical, as well as resistance in low-temperature degradation have been observed. Potential applications of this class of material in the dental field are discussed, summarizing the results of the latest scientific research.

Digital bar prototype technique for full-arch rehabilitation on implants.

BACKGROUND AND OVERVIEW: The aim of the authors in this case report was to describe a new approach to using the digital bar prototype technique for complete digital full-arch implant rehabilitation. Two combinable structures were used during the same visit as prototypes to simultaneously test the implant locations and the prosthetic parameters. Then the structures were joined together to form the final prosthesis. CASE DESCRIPTION: After the implant integration with the immediate provisional restoration, 3 sets of digital impressions were obtained to obtain a master digital model (MDM). A stereolithographic model with implant analogs was printed on the basis of the MDM. A titanium bar with implant connections and a functional resin structure were milled on the basis of the MDM and used as prototypes. To check the accuracy of the implant impression, the titanium prototype was tried in, and clinical and radiographic tests were performed. Then the resin prototype was slid into the positional prototype and fitted to the patient, and the esthetic and occlusal properties were evaluated and refined. Definitive restoration was obtained by luting the 2 prototypes together and finalizing the prosthesis with pink resin. CONCLUSIONS AND PRACTICAL IMPLICATIONS: The prototypes allowed the clinician to simultaneously verify the accuracy of the digital impressions and test the prosthetic parameters in 1 visit. Moreover, they were used to create the final restoration. The digital bar prototype technique also allowed for the reduction of clinical and laboratory time in a full-arch rehabilitation on implants. Nevertheless, obtaining a full-arch impression in an edentulous arch can be challenging, and further studies are necessary to evaluate the long-term success of this technique.