How well does Invisalign ClinCheck predict actual results: A prospective study.

INTRODUCTION: This study aimed to compare achieved movements with predicted movements after 28-week use of Invisalign Lite aligners. SETTINGS AND SAMPLE POPULATION: The digital impressions of 21 subjects treated with Invisalign Lite at a private practice and in the dental clinic (Milan, Italy) were taken and analysed. Subjects were Caucasian with a mean age of 20.1 years. METHODS: Patients were analysed at two time points: at T0, before starting therapy, and at T1, after 28 weeks of treatment with Invisalign clear aligners, with a 2-week change interval. The changes that occurred between T0 and T1 were compared to the predicted changes between T0 and Ts (setup/ClinCheck). Tooth movement performance was estimated through variables calculated as the difference between obtained and planned movements. RESULTS: In both maxillary and mandibular arches, the teeth that exhibited the least accurate expression of torque were the central incisors. Tip was not accurate on maxillary central incisors and canines, mandibular central incisors, lateral incisors, first premolars, second premolars and first molars. Rotations were under-expressed on maxillary lateral incisors, canines and second premolars and on mandibular central incisors, canines, first premolars, second premolars and first molars. The overall angular changes showed a tendency to underperformance. Transverse linear changes were accurate with a significant overperformance on maxillary and mandibular first molars. CONCLUSIONS: Torque correction of maxillary central incisors, as well as rotational correction of most of the teeth, showed significant differences between what was planned and what was obtained.

Palatal changes after treatment of functional posterior cross-bite using elastodontic appliances: a 3D imaging study using deviation analysis and surface-to-surface matching technique.

BACKGROUND: The present study aimed to evaluate the changes in palate dimension and morphology after treatment of functional posterior crossbite (FPXB) with elastodontic devices (EAs). METHODS: The treatment group (TG) consisted of 25 subjects (mean age 7.3 ± 0.9 years) who received treatment with EA for one year. The control group (CG) comprised 14 untreated subjects (mean age 6.8 ± 0.7 years). INCLUSION CRITERIA: intra-oral scan registered before (T0) and after treatment (T1), FPXB with a mandibular shift towards the crossbite site of ≥ 2 mm, class I molar relationship. EXCLUSION CRITERIA: missing teeth, anterior crossbite, temporomandibular disorders, previous orthodontic treatment, carious lesions, mobility of deciduous posterior teeth, craniofacial deformities. Digital models were analyzed to assess the inter-canine (ICW) and inter-molar widths (IMW) and the corresponding emi-lateral measurements (eICW and eIMW) using the median palatine plane as reference. According to a specific 3D imaging technology, the morphology and symmetry of the palate was investigated by analysing the 3D deviation between the two specular models of the palate. RESULTS: At T0, both groups showed a significantly narrower dimension of eICW and eIMW at the crossbite side compared to the non-crossbite side (p < 0.05). Also, the 3D deviation analysis demonstrates a limited matching percentage of the original/mirrored models in both TG (81.12%) and CG (79.36%), confirming the asymmetry of the palate. The area of mis-matching was located at the alveolar bone level. At T1, subjects in the TG showed a significant increment of ICW and IMW (p < 0.05), a reduction of the differences of eICW and eIMW between both sides (p < 0.05) and an increment of the percentage matching (TG = 92.32%) (p < 0.05), suggesting a significant recovery of the palatal asymmetry. No significant changes were found between T0 and T1 in the CG (p > 0.05). CONCLUSIONS: EAs could be successfully used to correct FPXB in mixed dentition and could restore the harmonious development of the palate in children.

Oral and throat microbiological changes after orthodontic debonding.

As already known, orthodontic treatment presents a factor of plaque retention, promoting an increase of bacterial growth in the oral cavity. Nevertheless, after orthodontic debonding an alteration of the previous microbiological status may occur. The present study was designed to assess variations among six bacterial species in the oral cavity and the status of oral health after orthodontic debonding. At the end of the fixed orthodontic treatment, 30 patients were divided into three groups based on the type of retention: I - 10 patients were treated with upper and lower fixed retention devices, II - 10 with upper and lower removable retention devices, and III - 10 with lower fixed and upper removable retention devices. To assess the alterations of oral microbiota after orthodontic debonding, two salivary swabs were collected for each individual: the first immediately after debonding (T0) and the other one 6 weeks later (T1). Six species, the ones most correlated with the development of caries and periodontal disease, were selected for microbiological analysis with Real-time PCR: Streptococcus mutans, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, and Fusobacterium nucleatum. Furthermore, in order to correlate the microbiological outcomes with the clinical condition, oral health indexes at T0 and T1 were assessed for all patients. Six weeks after debonding, the salivary levels of the bacteria investigated tend to decrease and the values of the oral health indexes tend to improve with all types of treatment considered (p<.05). Salivary bacteria levels and oral health are similarly influenced by fixed and/or removable orthodontic retentions.

The step further smile virtual planning: milled versus prototyped mock-ups for the evaluation of the designed smile characteristics.

BACKGROUND: Mock-up based approach allows the preview of the aesthetic rehabilitation, however, it is crucial that the mock-up does not differ from the expected aesthetic outcomes. With CAD-CAM technologies, it is possible to directly create mock-ups from virtual planned smile project, with greater accuracy and efficiency compared to the conventional moulded mock-ups. In this study, we investigated the trueness of mock-ups obtained with milling and 3D printing technology and a full digital work-flow system. METHODS: Ten adults subjects were included and digital smile design/digital wax-up were performed to enhance the aesthetic of maxillary anterior region. Ten milled mock-ups and 10 prototyped mock-ups were obtained from the original .stl file and a digital analysis of trueness was carried out by superimposing the scanned-milled mock-ups and the scanned-prototyped mock-ups to the digital wax-up, according to the surface-to-surface matching technique. Specific linear measurements were performed to investigate and compare the dimensional characteristics of the physical manufactures, the 3D project and the scanned mock-ups. All data were statistically analyzed. A clinical test was also performed to assess the fitting of the final manufacture. RESULTS: The prototyped mock-ups showed a significant increment of the transversal measurements (p < 0.001) while the milled mock-ups showed a significant increment of all vertical and transversal measurements (p < 0.001). The prototyped mock-ups showed good fitting after clinical tests while none of the milled mock-ups showed good adaptation (no fitting or significant clinical compensation required). Deviation analysis from the original 3D project reported a greater matching percentage for the scanned-milled mock-ups (80,31% ± 2.50) compared to the scanned-prototyped mock-ups (69,17% ± 2.64) (p < 0.001). This was in contrast with the findings from linear measurements as well as from the clinical test and may have been affected by a reductive algorithmic computation after digitization of physical mock-ups. CONCLUSION: Both prototype and milled mock-ups showed a slight dimensional increment comparing to the original 3D project, with milled-mock-ups showing less fitting after clinical tests. Caution must be taken when assessing the trueness of scanned manufacture since an intrinsic error in the system can underestimate the dimensions of the real object.

Transverse and torque dental changes after passive self-ligating fixed therapy: A two-year follow-up study.

INTRODUCTION: Self-ligating appliances are purposed to expand the arches, but evidence on stability of the result is lacking. We measured the width of maxillary and mandibular arches and torque changes after treatment with the use of passive self-ligating appliances and assessed stability at the 2-year follow-up. METHODS: Maxillary and mandibular 3-dimensional (3D) models from 32 subjects (mean initial age 14.9 ± 0.9 years), consecutively treated with the use of self-ligating appliances, were obtained before, immediately after, and 2 years after treatment. Dental arches were examined with the use of 3D software to evaluate differences in transverse arch dimensions and torque values. RESULTS: An incremental increase of arch widths was recorded, especially regarding maxillary and mandibular premolars. The increase in the transverse diameters was associated with a significant positive torque gain. No significant changes in arch perimeter and depth were recorded. In the retention period, slight significant changes in transverse diameters were recorded, and a transverse diameter constriction detected. Torque values remained almost unchanged in the follow-up period. CONCLUSIONS: Transverse arch dimensions, along with torque values, increased significantly after treatment with the use of a passive self-ligating appliance. In the 2 years following treatment, a tendency to transverse diameter restriction, especially for the maxillary and mandibular premolars, was observed.

Treatment of Severe Maxillary Hypoplasia With Combined Orthodontics and Distraction Osteogenesis.

Distraction osteogenesis (DO) is a technique that allows the generation of new bone in a gap between 2 vascularized bone surfaces in response to the application of graduated tensile stress across the bone gap.Distraction osteogenesis has become a routine treatment of choice to correct skeletal deformities and severe bone defects in the craniofacial complex over the past decade. Distraction osteogenesis has been successfully chosen in lengthening the maxilla and the mandible; in the maxilla and recently in the mandible, the jawbones have been distracted and widened transversely to relieve severe anterior dental crowding and transverse discrepancies between the dental arches.Distraction osteogenesis for maxillary advancement started in 1993 and is now widely used, especially in patients with skeletal Class III malocclusion caused by maxillary hypoplasia.The aim of this study was to present the efficiency of combined orthodontic and DO in the severe maxillary hypoplasia.A 35-year-old Italian man presented to our clinical practice with the chief complaint of esthetic and functionally problems because of skeletal Class III malocclusion with anterior crossbite.Considering that the severity of the skeletal discrepancy is remarkable but compensated by the DO potential, the combined orthodontic and DO treatment was considered adequate, like less invasive and equally effective.It was obtained a good alignment with the upper and lower arch dental alveolar maxillary advancement that allowed to correct the sagittal relationships.The patient was satisfied for the treatment results and had considerable improvement in his self-esteem.

Histomorphometric Evaluation of Two Different Bone Substitutes in Sinus Floor Augmentation Procedures.

The aim of this study is to compare the histomorphometric data of deproteinized bovine bone (DBB) and a fully synthetic bone substitute, poly (lactic-co-glycolic) acid/hydroxyapatite (PLGA/HA) applied for sinus floor augmentation technique. Twelve maxillary atrophic ridges of 8 patients requiring major maxillary sinus floor augmentation were studied; the sites were randomly assigned to the study groups and reexamined at 6 months after grafting using cone beam computed tomography scans and biopsy samples harvested during dental implant placement. Total bone volume, residual graft material volume, and new bone volume were assessed. Measurable biopsies were available from 67% of test sites and 100% of control sites. Poly (lactic-co-glycolic) acid/hydroxyapatite grafts showed no trace of graft material, whereas DBB grafts had a mean graft area of 16.60%. Mean percent of newly formed bone tended to be greater for PLGA/HA than for DBB group. Mean total bone volume percent did not differ significantly: PLGA/HA = 44.45% (CI, 16.42-72.48), DBB = 44.11% (CI, 36.61-51.60). Deproteinized bovine bone and PLGA/HA produced similar total bone volumes. Poly (lactic-co-glycolic) acid/hydroxyapatite appeared to be completely replaced by newly formed bone, whereas DBB presented significant amounts of residual graft material. Poly (lactic-co-glycolic) acid/hydroxyapatite necessitates of more clinical trials to be considered suitable for sinus floor augmentation.

Non-surgical periodontal treatment of peri-implant diseases with the adjunctive use of diode laser: preliminary clinical study.

Peri-implant diseases present in two forms: peri-implant mucositis and peri-implantitis. The prevalence of peri-implant complications is significantly rising. The aim of this study was to compare conventional treatment of inflamed peri-implant tissues with conventional treatment together with diode laser application. Twenty-seven patients (age 36 to 67, 15 women and 12 men, 12 smokers and 15 non-smokers) requiring treatment for mucositis or peri-implantitis were taken into account for this preliminary study. Plaque index (PI), pocket depth (PD), and bleeding on probing (BoP) were recorded at baseline evaluation. Patients in control group (CG) received conventional non-surgical periodontal treatment. Patients in test group received conventional non-surgical periodontal treatment together with diode laser application (810 nm, 30 s, 1 W, 50 Hz, t on = 100 ms, t off = 100 ms, energy density = 24.87 J/cm(2)). Paired t test was used to evaluate the difference in repeated measurements of considered indexes at T 0 and T 1 (1 year) in both groups. A total of 606 sites were taken into account in the test group (TG) and 144 in the CG. PD mean variation in the TG was 2.66 mm ± 1.07, while mean PD variation in the CG was 0.94 ± 1.13 mm. Paired t testing of the variation in PD in CG and TG revealed a statistically significant difference between the two groups (p < 0.0001). A reduction of pathological sites from 89 % (T 0) to 14.35 % (T 1) was achieved in the TG, while reduction obtained in the CG was from 75.69 % (T 0) to 50 % (T 1); BoP scores at time T 1 had fallen below 5 % in the TG and decreased to 59.7 %, in the CG. Within the limitations of this study, diode laser seems to be an additional valuable tool for peri-implant disease treatment.

The distraction osteogenesis in midfacial hypoplasia.

Distraction osteogenesis (DO) can generate new bone in a gap between 2 vascularized bone surfaces in response to application of graduated tensile stress across the bone gap. The authors present the clinical result in a cleft patient with severe maxillary deficiency treated by a rigid external distraction (RED) device. A boy complained of both masticatory and psychological problems because of cleft with severe midfacial retrusion. The treatment aimed to create a well-balanced facial profile, increase maxillary incisal display, create proper overjet and overbite, and align his dentition. By the RED system, the traction is applied to the maxilla through the dentition by an intraoral splint. A complete Le Fort I osteotomy was performed, including pterygomaxillary and septal disjunction, with mobilization. Once osteotomy was completed, the halo portion of the RED device was adjusted for the width of the neurocranium and was rigidly fixed around the head with 2 scalp screws on each side. A well-balanced facial profile and a good alignment of the dentition were obtained. The patients had considerable improvement in his self-esteem. Clinical reports have suggested that maxillary advancements achieved by distraction are more stable than those achieved with orthognathic surgery with a minimal influence on velopharyngeal competence.

Piezosurgery versus conventional osteotomy in orthognathic surgery: a paradigm shift in treatment.

The aim of the study was to compare in a randomized controlled clinical trial the use of the piezoelectric osteotomy as an alternative to the conventional approach in terms of surgery time, intraoperative blood loss, cut quality, nerve injury, and costs.One hundred ten patients who had orthognathic surgery procedures with bimaxillary osteotomy were divided into 2 groups: group A was treated with a piezosurgery device, and group B, with a reciprocating saw and bur.The piezosurgical bone osteotomy permitted individualized cut designs. The surgical time in group A was reduced, with a mean for the mandibular osteotomy (1 side) between 3 minutes 31 seconds and 5 minutes 2 seconds, whereas in group B, the surgical time was between 7 minutes 23 seconds and 10 minutes 22 seconds. The surgical time in group A for the Le Fort I osteotomy was between 5 minutes 17 seconds and 7 minutes 55 seconds in group A and between 8 minutes 38 seconds and 15 minutes 11 seconds in group B. All patients in group A had a low blood loss (<300 mL) versus patients of group B who had a medium to high blood loss (medium loss: 400 mL, high loss: >500 mL). Inferior alveolar nerve sensation was retained in 98.2% of group A versus 92.7% in group B at 6 months postoperative testing.Piezoelectric osteotomy reduced surgical time, blood loss, and inferior alveolar nerve injury in bimaxillary osteotomy. Absence of macrovibrations makes the instrument more manageable and easy to use and allows greater intraoperative control with higher safety in cutting in difficult anatomical regions.

Radiographic evaluation of regenerated bone following poly(lactic-co-glycolic) acid/hydroxyapatite and deproteinized bovine bone graft in sinus lifting.

Although numerous biomaterials are used for maxillary sinus-lift surgery, the ideal material for such procedures has not yet been identified. Both heterologous and alloplastic bone substitutes have a solely osteoconductive effect and lack the osteoinductive properties of the bone morphogenetic proteins typical of autologous bone. Our group assessed a new alloplastic graft material, poly(lactic-co-glycolic) acid/hydroxyapatite (PLGA/HA), implanted in a human model of maxillary sinus-lift surgery. For this prospective, random, double-blind trial, we used deproteinized bovine bone (DBB) as the comparison material. Radiographic bone vertical height and density were assessed at approximately 28 weeks after grafting using cone-beam computed tomography. The vertical dimension of the regenerated bone was equivalent between the 2 groups. The density of the bone regenerated using PLGA/HA was significantly lower than that obtained with DBB. Despite clinical assessments demonstrating that PLGA/HA has sufficient characteristics for use in sinus-lift surgery, DBB provided greater bone density and an equivalent vertical dimension of grafted bone. Further studies are needed to supplement the radiologic findings with histologic and micromorphometric examinations.

Prevalence of white-spot lesions before and during orthodontic treatment with fixed appliances.

The aim of the study was to determine the prevalence of white-spot lesions (WSLs) in patients with fixed orthodontic appliances. The cross-sectional study sample consisted of three groups of patients: group I, 59 patients treated orthodontically for 6 months; group II, 64 patients treated for 12 months; group 0 (control), 68 patients examined immediately before appliance placement. All groups were treated with a 0.022-inch slot preadjusted appliance and they wore a functional fixed appliance. The presence of WSLs was evaluated by visual examination using the scoring system proposed by Gorelick. The groups were evaluated for differences in the prevalence of at least one WSL using Fisher's exact test, followed by Bonferroni pairwise comparisons. The prevalence of WSLs by tooth type was evaluated with logistic regression (P < 0.05). Intraobserver agreement was assessed by means of the Cohen ĸ statistical method. There were no significant differences in the prevalence of WSLs between patients treated for 6 and 12 months (P = 0.855); however, there were significantly more WSLs in groups I and II than in group 0 (P = 0.000). No significant differences were found between girls and boys (P = 1.000). The mandibular first molars and maxillary lateral incisors were the most affected teeth, in both the treated and untreated groups. The study revealed significant decalcification at 6 months after orthodontic bonding. Considering how quickly these lesions can develop and become irreversible, early diagnosis is of critical importance.

Analysis of Mandibular Muscle Variations Following Condylar Fractures: A Systematic Review.

This review analyzes muscle activity following mandibular condylar fracture (CF), with a focus on understanding the changes in masticatory muscles and temporomandibular joint (TMJ) functioning. MATERIALS AND METHODS: The review was conducted following the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. A search was performed on online databases using the keywords "masticatory muscles" AND ("mandibular fracture" OR "condylar fracture"). The eligibility criteria included clinical trials involving human intervention and focusing on muscle activity following a condylar fracture. RESULTS: A total of 13 relevant studies were reviewed. Various studies evaluated muscle activity using clinical evaluation, bite force measurement, electromyography (EMG), magnetic sensors and radiological examinations to assess the impact of mandibular fractures on masticatory muscles. CONCLUSIONS: Mandibular condylar fractures can lead to significant changes in muscle activity, affecting mastication and TMJ functioning. EMG and computed tomography (CT) imaging play crucial roles in assessing muscle changes and adaptations following fractures, providing valuable information for treatment planning and post-fracture management. Further research is required to explore long-term outcomes and functional performance after oral motor rehabilitation in patients with facial fractures. Standardized classifications and treatment approaches may help improve the comparability of future studies in this field.

Efficacy of the Cervical Vertebral Maturation Method: A Systematic Review.

OBJECTIVE: The present systematic review was carried out to evaluate both qualitatively and quantitatively the effectiveness of the cervical vertebral maturation (CVM) method in predicting the pubertal growth spurt. METHODS: PubMed, PMC, Scopus, SciELO, Cochrane Central Register of Controlled Trials (CENTRAL), and Web of Science databases were searched. The research included every article published from 1970 to June 2019, featuring the keywords: ("cervical vertebrae" OR ("cervical" AND "vertebrae") AND ("orthodontics" OR "growth and development" OR ("growth" AND "development") OR ("growth"). The Preferred Reporting Items for Reporting Systematic Reviews and Meta Analyses (PRISMA) protocol was adopted, and quality assessments modified from the "Strengthening the Reporting of Observational Studies in Epidemiology" (STROBE) and the "Standards for the Reporting of Diagnostic Accuracy Studies" (STARD) were performed to conduct this systematic review. RESULTS: Initially, 1284 articles were found. All the articles were then examined, and 43 studies met the inclusion criteria. Sixteen articles had low-quality scores, 25 had moderate scores, and 2 had high scores. The results showed a moderate to high statistically significant correlation between the CVM and other maturation methods. CONCLUSION: Overall, the CVM method can be considered an effective method and may be used with other skeletal indices for the radiographic assessment of skeletal maturity, and also to identify the growth peak in growing patients.

Wiskott-Aldrich syndrome: Oral findings and microbiota in children and review of the literature.

OBJECTIVE: Wiskott-Aldrich syndrome (WAS) is a rare X-linked primary immunodeficiency, characterized by micro-thrombocytopenia, recurrent infections, and eczema. This study aims to describe common oral manifestations and evaluate oral microbioma of WAS patients. MATERIAL AND METHODS: In this cohort study, 11 male WAS patients and 16 male healthy controls were evaluated in our Center between 2010 and 2018. Data about clinical history, oral examination, Gingival Index (GI) and Plaque Index (PI) were collected from both groups. Periodontal microbiological flora was evaluated on samples of the gingival sulcus. RESULTS: WAS subjects presented with premature loss of deciduous and permanent teeth, inclusions, eruption disturbance, and significantly worse GI and PI. They also showed a trend toward a higher total bacterial load. Fusobacterium nucleatum, reported to contribute to periodontitis onset, was the most prevalent bacteria, together with Porphyromonas gingivalis and Tannerella forsythia. CONCLUSIONS: Our data suggest that WAS patients are at greater risk of alterations in the oral cavity. The statistically higher incidence of periodontitis and the trend to higher prevalence of potentially pathological bacterial species in our small cohort, that should be confirmed in future in a larger population, underline the importance of dentistry monitoring as part of the multidisciplinary management of WAS patients.

Biological effect of resorbable plates on normal osteoblasts and osteoblasts derived from Pfeiffer syndrome.

Biodegradable fixation devices made of the polymers polylactide, polyglycolide and their copolymers are used routinely during maxillofacial, craniofacial, and orthopedic reconstructive surgical procedures, thanks to their property of biodegradation that avoid the need for implant removal. In particular, they are used in the treatment of craniosynostosis in pediatric patients affected by Pfeiffer syndrome, where the resorption time of 1 year or less does not interfere with the normal growth of the skull. To study the mechanism how polylactide-polyglycolide (PLPG) acid plates can induce osteoblast differentiation and proliferation in normal osteoblasts and in osteoblasts derived from a patient with Pfeiffer syndrome, the expression levels of bone-related genes were analyzed using real-time reverse transcription-polymerase chain reaction. Osteoblasts grown on the PLPG acid plates resulted in significant upregulation of mRNA expression of many genes related to osteodifferentiation during the treatment, indicating that polylactide, polyglycolide biopolymers enhance proliferation, differentiation, and deposition of matrix in osteoblasts. This study also revealed some differences in gene expression between normal osteoblasts and osteoblasts derived from patients with Pfeiffer syndrome, cultivated on PLPG acid plates.

Stannous Fluoride Preventive Effect on Enamel Erosion: An In Vitro Study.

The aim of this in vitro study was to evaluate the effects of a single dose application of two daily toothpastes on enamel exposed to acid attack. The research was conducted on human molars enamel fragments (n = 72). The two different toothpastes active ingredients were sodium fluoride (NaF) and stannous fluoride (SnF2). They were compared in protecting the surface of the enamel exposed to three acids: citric acid, lactic acid and hydrochloric acid. A spectrophotometer was used to measure the calcium ions and phosphate released in the solutions by the enamel specimens. Afterward, ionic concentrations were analyzed through the t-Student test, in order to estimate the significance level (p < 0.05) of the solubility differences obtained between the treatment and control groups. Finally, sample surfaces were analyzed with scanning electron microscopy and X-ray energy dispersive spectroscopy (SEM/EDX). The two analyzed toothpastes did not reveal any statistically significant variation in the release of calcium and phosphate (p > 0.05). Nevertheless, acid-resistant deposits were detected in samples treated with stannous fluoride and exposed to lactic acid, though the presence of tin ion deposits on samples treated with stannous fluoride was not shown. A single dose of a fluoride-based toothpaste before different acids attack, in simulated oral cavity conditions, did not show a significant preventive effect.

One Step before 3D Printing-Evaluation of Imaging Software Accuracy for 3-Dimensional Analysis of the Mandible: A Comparative Study Using a Surface-to-Surface Matching Technique.

The accuracy of 3D reconstructions of the craniomaxillofacial region using cone beam computed tomography (CBCT) is important for the morphological evaluation of specific anatomical structures. Moreover, an accurate segmentation process is fundamental for the physical reconstruction of the anatomy (3D printing) when a preliminary simulation of the therapy is required. In this regard, the objective of this study is to evaluate the accuracy of four different types of software for the semiautomatic segmentation of the mandibular jaw compared to manual segmentation, used as a gold standard. Twenty cone beam computed tomography (CBCT) with a manual approach (Mimics) and a semi-automatic approach (Invesalius, ITK-Snap, Dolphin 3D, Slicer 3D) were selected for the segmentation of the mandible in the present study. The accuracy of semi-automatic segmentation was evaluated: (1) by comparing the mandibular volumes obtained with semi-automatic 3D rendering and manual segmentation and (2) by deviation analysis between the two mandibular models. An analysis of variance (ANOVA) was used to evaluate differences in mandibular volumetric recordings and for a deviation analysis among the different software types used. Linear regression was also performed between manual and semi-automatic methods. No significant differences were found in the total volumes among the obtained 3D mandibular models (Mimics = 40.85 cm3, ITK-Snap = 40.81 cm3, Invesalius = 40.04 cm3, Dolphin 3D = 42.03 cm3, Slicer 3D = 40.58 cm3). High correlations were found between the semi-automatic segmentation and manual segmentation approach, with R coefficients ranging from 0,960 to 0,992. According to the deviation analysis, the mandibular models obtained with ITK-Snap showed the highest matching percentage (Tolerance A = 88.44%, Tolerance B = 97.30%), while those obtained with Dolphin 3D showed the lowest matching percentage (Tolerance A = 60.01%, Tolerance B = 87.76%) (p < 0.05). Colour-coded maps showed that the area of greatest mismatch between semi-automatic and manual segmentation was the condylar region and the region proximate to the dental roots. Despite the fact that the semi-automatic segmentation of the mandible showed, in general, high reliability and high correlation with the manual segmentation, caution should be taken when evaluating the morphological and dimensional characteristics of the condyles either on CBCT-derived digital models or physical models (3D printing).

Invisalign appliance: aesthetic and efficiency.

BACKGROUND: The patients' request for treatment with clear aligners is constantly increasing. The aligners permit to the clinicians a valid way to solve a lot of orthodontic cases but the patients' compliance and the clinicians' capabilities and knowledge of the technique is fundamental for the outcome. METHODS: Seventy-two digital models of 18 consecutive patients treated with Invisalign and Smart Track aligners for 14 weeks were analyzed. The operator positioned 24 points on each model and were obtained the values of arch depth and perimeter of arch before and after the treatment. The variations of measurement were calculated with t student test. RESULTS: A decrease of arch depth and perimeter was found from t0 to t1 and the most relevant difference was observed in the upper arch depth with a decrease of 1.3 mm and in the upper arch perimeter with a difference of 1.1 mm. CONCLUSIONS: There was always a decrease of the values of arch depth and arch perimeter at the end of the treatment, especially in the upper arch. These changes must be considered by the clinicians to perform a better treatment to obtain the most predictable results and a patient's higher satisfaction.