Evaluation of Intraoral Full-Arch Scan versus Conventional Preliminary Impression.

An accurate impression is vital during prosthodontic rehabilitation. Digital scanning has become an alternative to conventional impressions. This study compares conventional preliminary impression techniques with digital scanning, evaluating the efficiency, treatment comfort, and trueness. Impressions of 28 patients were taken using conventional and digital techniques. The efficiency of both impression techniques was evaluated by measuring the mean working time. A visual analog scale questionnaire (1-10) was used to appreciate the participants' perceptions of discomfort. Morphometric measurements, which were carried out to determine the differences between the casts, were made on the buccolingual cross sections of teeth 11 and 31 and the distolingual and mesiobuccal cusp tips of each first molar. The total treatment time was 75.5 min for conventional and 12 min for digital impressions. The patients scored a mean discomfort assessment of 6.66 for conventional and 9.03 for digital scanning. No significant differences existed between the examined areas (p < 0.05, Wilcoxon and Mann-Whitney tests) of the digital casts obtained by both techniques. The intraoral scan can be considered as an alternative to conventional preliminary impressions for performing study model analysis during orthodontic treatment planning. The digital impression is more comfortable and accepted by the patients than the conventional impression and has a shorter working time.

Genetic and Morphological Variation in Hypodontia of Maxillary Lateral Incisors.

(1) Background: Hypodontia has a multifactorial aetiology, in which genetic factors are a major component. Associated with this congenital absence, the formed teeth may show differences in size and shape, which may vary with the specific genetic variants and with the location of the missing teeth. The aims of the present study were to investigate a specific variant of MSX1, derive morphometric tooth measurements in a sample of patients with isolated maxillary lateral incisor agenesis and matched controls, and model the findings. (2) Methods: Genotyping of the MSX1 rs8670 genetic variant and morphometric measurements with a 2D image analysis method were performed for 26 hypodontia patients and 26 matched controls. (3) Results: The risk of upper lateral incisor agenesis was 6.9 times higher when the T allele was present. The morphometric parameters showed significant differences between hypodontia patients and controls and between the unilateral and bilateral agenesis cases. The most affected crown dimension in the hypodontia patients was the bucco-lingual dimension. In crown shape there was significant variation the Carabelli trait in upper first molars. (4) Conclusions: The MSX1 rs8670 variant was associated with variations in morphological outcomes. The new findings for compensatory interactions between the maxillary incisors indicate that epigenetic and environmental factors interact with this genetic variant. A single-level directional complex interactive network model incorporates the variations seen in this study.

Clinical bracket failure rates between different bonding techniques: a systematic review and meta-analysis.

BACKGROUND: Bracket failure increases the treatment time of orthodontic therapy and burdens patients with unnecessary costs, increased chair time, and possible new appointments. OBJECTIVE: To compare the bond failures of different orthodontic materials based on the results of available clinical studies. SEARCH METHODS: A systematic search of clinical trials was performed in the Cochrane, Embase, and Pubmed databases with no limitations. The list of investigated techniques contained conventional acid-etch primer (CM-AEP), self-etch primer (SEP), self-cure resin (SCR), and simple or resin-modified glass ionomer (RM-GIC) materials and procedures. SELECTION CRITERIA: Clinical studies reporting the failure rate of bonded brackets after using direct adhesive techniques on buccal sites of healthy teeth were included. DATA COLLECTION AND ANALYSIS: Bracket failure rates from eligible studies were extracted by two authors independently. Risk ratios (RRs) were pooled using the random-effects model with DerSimonian-Laird estimation. RESULTS: Thirty-four publications, involving 1221 patients, were included. Our meta-analysis revealed no significant difference in the risk of bracket failures between SEP and CM-AEP. After 6, 12, and 18 months of bonding, the values of RR were 1.04 [95% confidence interval (CI), 0.67-1.61], 1.37 (95% CI, 0.98-1.92), and 0.93 (95% CI, 0.72-1.20), respectively. At 18 months, bracket failure was 4.9 and 5.2% for SEP and CM-AEP, respectively. Heterogeneity was good or moderate (I2 < 42.2%). The results of RM-GIC at 12 months indicated a 57% lower risk of bracket failure using SCR as compared with RM-GIC (RR: 0.38; 95% CI, 0.24-0.61). At 18 months, bracket failures for SCR and RM-GIC were 15.8 and 36.6%, respectively (RR: 0.44; 95% CI, 0.37-0.52, I2 = 78.9%), demonstrating three to six times higher failure rate than in the case of etching primer applications. LIMITATIONS: A major limitation of the present work is that the included clinical trials, with no exceptions, showed variable levels of risk of bias. Another possible problem affecting the outcome is the difference between the clustering effects of the split mouth and the parallel group bracket allocation methods. CONCLUSIONS AND IMPLICATIONS: The results revealed no significant difference between SEP and CM-AEP up to 18 months after application. RM-GIC had much worse failure rates than acid-etching methods; additionally, the superiority of SCR over RM-GIC was evident, indicating strong clinical relevance. REGISTRATION: Prospero with CRD42020163362.

Updating Standards of Facial Growth in Romanian Children and Adolescents Using the Anthropometric Method-A Pilot Study.

The anthropometric method is an important tri-dimensional and non-invasive assessment instrument for accurate diagnosis in paedodontics, orthodontics, and other medical fields. Our aim was to propose a technique that is accessible for clinicians and to determine the reference values for Romanian children and adolescents for the facial parameters selected. We proposed three basic instruments: a plastic compass, a ruler, and a digital caliper. Eighty-five children and adolescents (62% girls and 38% boys), aged between 3.5 and 14.5 years, were included in the study. We selected eight transversal, 12 vertical, and three sagittal measurements. Facial indices, according to Farkas L.G., were directly determined. The correlations between facial and general growth parameters, using Pearson correlation coefficient, for the entire sample were significant, direct, and strong for the following: Zy-Zy, Go-Go, N-Gn, N-Sn, Sto-Gn, Tr-Gn, Tr-Sn, Tr-Tr (r = 0.526-0.925, p < 0.001), and insignificant for Sn-Sto (r = 0.099-0.124, p > 0.354). The highest correlation coefficient is exhibited by Tr-Gn (r = 0.893 with height and r = 0.925 with weight). When performing a gender related comparison, we noticed that the vertical and transversal linear parameters and some facial indices are increased in boys (p < 0.05), depending on the age group. The simplified anthropometric technique represents an accessible method to every clinician, bringing important information related to dentofacial growth, diagnosis, and treatment planning in dentistry.

Observational Study Regarding Possible Side Effects of Miniscrew-Assisted Rapid Palatal Expander (MARPE) with or without the Use of Corticopuncture Therapy.

The use of maxillary expanders has the effect of distancing the maxillary bones at the level of the median palatal suture. During maxillary expansion, the main resistance forces occur at the zygomatico-maxillary sutures, and not in the median palatal suture, which is the basic principle on which this method is based. In this observational study, we evaluated possible complications at the skeletal and dentoalveolar level after palatal split using miniscrew-assisted rapid palatal expansion (MARPE) associated or not with corticopuncture (CP) therapy. The study included 27 patients with maxillary transverse deficiency and unilateral or bilateral cross-bite. Skeletal and dentoalveolar changes were evaluated using cone beam computed tomography (CBCT) images acquired before and after expansion. The mid-palatal suture was separated in 88.88% of cases, buccal bone height of the alveolar crest had decreased at first molar both at oral and palatal level by approximately 2.07 mm in 40.7% of cases whilst the remaining 59.3% showed insignificant bone loss, with canines exhibiting buccal tipping of 4.10° in 62.5% of cases. Changes of the occlusal planes were observed in 10 cases (37%). Maxillary canines tended to show symmetric buccal inclinations relative to the maxillary basal bone. Six patients; 22.22% showed hypertrophy/hyperplasia of the palatal mucosa associated with ulcerations, erythema, itching, and discomfort in the area. Swelling at the mid-palatal suture after split was observed in all cases and was caused by the resultant force. No cases of necrosis of the palatal mucosa were observed. Although occlusal modifications occur after palatal split, especially in unilateral cross-bite cases, these changes can be treated with the help of fixed orthodontic appliances.

Study of rs12532, rs8670 Polymorphism of Msh Homeobox 1 (MSX1), rs61754301, rs4904155 Polymorphism of Paired Box Gene 9 (PAX9), and rs2240308 Polymorphism of Axis Inhibitor Protein 2 (AXIN2) Genes in Nonsyndromic Hypodontia.

The etiology of hypodontia is complex, in which both genetic and environmental factors can be related. The main objective of our study was to contribute to elucidating the genetic background of nonsyndromic hypodontia (NSH). In this order, we selected 97 NSH subjects (70 females and 27 males) from patients referred to orthodontic treatment, and we matched to each NSH subject a control by age and sex. DNA was obtained from epithelial cells from the oral mucosa. Genotyping of the PAX9 (rs4904155 and rs61754301), MSX1 (rs8670 and rs12532), and AXIN2 (rs2240308) SNPs was performed by using TaqMan SNP Genotyping Assays on a real-time PCR system. Single-nucleotide polymorphisms (SNPs) were studied for the whole NSH group and for frontal and lateral agenesis NSH subjects separately. Our results showed that the variant genotype (p=0.0008, OR = 2.9, 95% CI = 1.58-5.3) and variant T allele (p=0.0002, OR = 2.65, 95% CI = 1.6-4.39) of the MSX1 rs8670 SNP increased the risk of hypodontia in the studied population when the whole NSH group was compared with controls. The variant genotype of the MSX1 rs8670 SNP was the most frequent in frontal agenesis; meanwhile in the lateral agenesis NSH group, the AXIN2 rs2240308 SNP showed a higher frequency of the variant genotype, with a trend towards statistical significance. In conclusion, the results of the present study showed that the variant genotype and variant T allele of the MSX1 rs8670 SNP increased the risk of hypodontia in the studied population. The presence of the variant A allele of AXIN2 rs2240308 is associated with frontal agenesis but not with lateral agenesis.

Assessment of Periodontopathogens in Subgingival Biofilm of Banded and Bonded Molars in Early Phase of Fixed Orthodontic Treatment.

To assess the prevalence and occurrence of eleven periodontopathogens in subgingival biofilm of banded and bonded molars during the first period of fixed orthodontic treatment. Subjects were selected from patients referred to orthodontic treatment and were divided in two groups: group A comprised fifteen patients (14.4±2.45 years of age) who received orthodontic bands on first permanent molars and group B of ten patients (15.7±1.87 years of age) with directly bonded tubes on the labial surface of the same teeth. Subgingival sample collection was performed before bands and tubes application and 4-7 weeks after attachment placement. DNA-strip tehnique was used to assess the presence of eleven putative periodontopathogens at each time point. Fusobacterium nucleatum, Eikenella corrodens and Capnocytophaga spp. were found in a large number of samples, other periodontopathogens were present in a smaller rate. The 4-7 weeks after attachment placement a slight increase of putative species was observed in both groups. The presence of orthodontic tubes and bands influence the accumulation and composition of subgingival microbiota. Higher level of oral hygiene should be achieved before and during orthodontic treatment in order to prevent any side effects on periodontal tissues.

Correlation Among Chronological Age, Dental Age and Cervical Vertebrae Maturity in Romanian Subjects.

Aim: The purpose of this study was to assess the correlation among the chronological age, the dental age and the skeletal maturity in adolescents and young adults. Materials and Methods: The material consisted of panoramic and lateral cephalometric radiographs of 221 subjects, 146 girls (mean age 13.79 ±2.90) and 75 boys (mean age 13.46 ±2.82), inhabitants of Mures County (Central Romania). The chronological age was defined as the time from birth to the day the radiographs were taken. The dental age was evaluated according to Demirjian's method for third molars mineralization stage. Skeletal maturity was evaluated on cephalometric radiographs using the cervical vertebrae maturation (CVM) method. Descriptive statistical and linear regression analysis was performed and a coefficient of correlation was calculated. Results: The mean values obtained for cervical stages for boys and girls were significant (p=0.0171). The third molar mineralization seems to be highly correlated with the gender's chronological age for the whole group and for both genders as well (p<0.0001). The medium age of the cervical maturation showed to be younger in girls than in boys in CS1, CS3, CS5 and CS6 stages. In CS4 stages female subjects are in advance with almost 12 months, these subjects start (CS1) and end (CS6) the cervical maturation at a younger age. Conclusions: The results indicate that significant correlation exist between the chronological age and the dental age when crown development ends and between the chronological age and CVM (CS1 and CS6 stages for girls and CS2 and CS5 stages for boys).

Mild hypodontia is associated with smaller tooth dimensions and cusp numbers than in controls.

OBJECTIVE: The associations seen clinically between variations in tooth number, size and shape reflect the repetitive genetic interactions occurring between the epithelium and mesenchyme during the initiation and morphogenetic stages of the Complex Adaptive System that is dental development. The aim of this study was to investigate the clinical relationship further by comparing multiple crown parameters, including cusp numbers, between patients with mild hypodontia and controls in a Romanian sample. DESIGN: Digital images of dental casts of the permanent dentition from 28 patients with mild hypodontia and 28 controls were used. Measurements from the vestibular and occlusal surfaces were performed using a 2D image analysis method and cusps, including the Carabelli trait, were counted. Two-way analysis of variance was performed. RESULTS: The dimensions of the mild hypodontia group had smaller values than the controls, with many measurements being significantly different (significance values varied from p=0.049 to p=0.001). The most affected regions were the upper and lower anterior region in both sexes. Mesio-distal, bucco-lingual and occlusal area and perimeter dimensions were affected. Females from the hypodontia group had significantly less tricuspidated lower premolars when compared with the control group. Carabelli cusps were present in the hypodontia group less frequently, the difference being highly significant (p=0.0002) in women. CONCLUSIONS: The hypodontia patients presented with reduced crown dimensions and shape compared with controls. This is the first published study to demonstrate smaller cusp numbers in patients with hypodontia than in controls. The findings are compatible with a model of dental development as a Complex Adaptive System incorporating associations between tooth number, size and shape.

Study of dental and skeletal disorders in mono- and dizygotic twins.

UNLABELLED: The aim of this study was to analyze and to compare the dental and skeletal morphology of mono- and dizygotic twins (MZ and BZ). MATERIAL AND METHODS: 10 sets of monozygotic (mean age: 18.5 years) and 10 sets of dizygotic (mean age: 19.7 years) twins were examined, cast analysis, ortopantomography and lateral cephalometric films were analyzed. RESULTS: The upper frontal teeth dimension and shape is the same in 99.69% of MZ and 93.91% of the DZ twins. In MZ twins we found different values for transversal arch width and upper intercanine distance. The dental malpositions were different in the DZ sets, especially in tranversal and sagital plan. The same differences were seen in the arch forms. The skeletal pattern was also different between the components of DZ twins. The cephalometric values showed slight differences of the interincisal angle both in MZ and DZ twins. CONCLUSIONS: Genetically influenced patterns can be explained by the results of our study.

Examination of Bolton Index comparing the traditional method with a 2-dimensional digital measurement method.

UNLABELLED: Index is one of the most important analyses in orthodontic treatment planning. It shows if there is a correct proportion in size between the maxillary and mandibular teeth. In this study we compared the digital and traditional method. METHODS: 35 dental casts were measured using a Vernier caliper. The mean value was compared with the measurements from the scanned images of the dental casts. RESULTS: The results showed that the digital method provided similar results with those of the traditional one with a mean difference of 0.23 mm. The Pearson correlation coefficients were very high and similar to each other: R = 0.989 and R = 0.988 for the Anterior Bolton Index (ABI) and Overall Bolton Index (OBI), respectively. No statistically significant differences were present from either the ANOVA or the paired t-tests. CONCLUSION: The used digital method is as accurate as the traditional one, it is faster and easier to carry out and it offers all the advantages of image storage and data for subsequent use.

A histological analysis of gingival condition associated with orthodontic treatment.

The aim of this histological study was to analyze the gingival reaction to fixed orthodontic appliances. Gingival specimens were obtained with minimal trauma from 11 patients treated with fixed appliances in different intervals during the orthodontic treatment, including post-treatment periods. Serial sections were stained with Hematoxylin-Eosin. T- and B-cells were identified by specific antibodies, using a double staining technique with Avidin-Biotin method. Histological observations demonstrated and confirmed the presence of gingivitis during orthodontic treatment. According to the usual histological evaluation, the biopsies revealed the presence of hyperplastic chronic inflammatory changes from mild to moderate severity. The lack of rapid increase of CD20+ cells demonstrated that the gingival inflammation did not cause overall tissue destruction.