Knowledge, attitudes, and interest in orthodontic treatment: a cross-sectional study in adults with stage III-IV periodontitis and secondary malocclusions.

BACKGROUND: An increasing number of patients with advanced stages of periodontitis are seeking for treatment options. The study aimed to determine interest in orthodontic treatment (OT) and its association with oral health status and knowledge about the disease in adult subjects with stage III-IV periodontitis. METHODS: 96 subjects ≥ 30 years, with stage III-IV periodontitis agreed to fill in a questionnaire and undergo a comprehensive periodontal-orthodontic examination. The questionnaire included 44 questions: demographic, dental, health related habits, self-perceived overall and oral health, knowledge of periodontitis, and attitude toward OT. The statistical analysis was performed using a paired-sample T-test, Receiver Operating Characteristic (ROC) and binary logistic regression analysis (LRA). RESULTS: Stage IV periodontitis was observed in 32.3% of subjects and Class II malocclusion was most prevalent (53.1%). More than half of subjects were interested in OT. Oral health, knowledge about periodontitis and age were significant predictors for interest in OT. CONCLUSIONS: Knowledge spread about OT possibilities in advanced stages of periodontitis is very important both for the dental community and older subjects to save natural dentition.

Heritability of cephalometric variables of airway morphology in twins with completed active growth.

BACKGROUND: The interplay between genetic and environmental impacts on dental and facial morphology has been widely analyzed, but little is known about their relative contributions to airway morphology. The aim of this study was to evaluate the genetic and environmental influences on the cephalometric variables of airway morphology in a group of postpubertal twins with completed craniofacial growth. MATERIALS AND METHODS: The materials comprised lateral head cephalograms of 94 pairs of twins (50 monozygotic, 44 dizygotic) with completed craniofacial growth. Zygosity was determined using 15 specific DNA markers. The computerized cephalometric analysis included 22 craniofacial, hyoideal, pharyngeal structural linear and angular variables. Genetic analysis and heritability estimation were performed using maximum likelihood genetic structural equation modeling (GSEM). Principal component analysis (PCA) was used to assess the correlations between cephalometric measurement variables. RESULTS: Upper airway dimensions showed moderate to high genetic determination (SPPW-SPP and U-MPW: a2 = 0.64 and 0.5, respectively). Lower airway parameters showed only common and specific environmental determination (PPW-TPP a2 = 0.24, e2 = 0.38; LPW-V c2 = 0.2, e2 = 0.63; PCV-AH c2 = 0.47, e2 = 0.28). The relationship between the maxilla and the hyoid bone (for variables PNS-AH, ANS-AH d2 = 0.9, 0.92, respectively) showed very strong additive genetic determination. The size of the soft palate was affected by additive and dominant genes. Its length (SPL) was strongly influenced by dominant genes, while its width (SPW) showed a moderate additive genetic influence. Owing to correlations in the behavior of variables, the data could be expressed in 5 principal components that jointly explained 36.8% of the total variance. CONCLUSIONS: The dimensions of the upper airway are strongly determined by genes, while the parameters of the lower airway depend mainly on environmental factors. TRIAL REGISTRATION: The protocol has been approved by the Kaunas Regional Ethical Committee (No. BE - 2-41., May 13, 2020).

Malocclusions, pathologic tooth migration, and the need for orthodontic treatment in subjects with stage III-IV periodontitis. A cross-sectional study.

BACKGROUND: Literature is scarce on malocclusion prevalence and orthodontic treatment need (OTN) in subjects with stage III-IV periodontitis. Study aims were to assess prevalence of primary and secondary malocclusions in subjects with stage III-IV periodontitis and OTN based on pathologic tooth migration (PTM) and occlusal trauma of anterior teeth (AT). SUBJECTS AND METHODS: One hundred and twenty-one subjects with stage III-IV periodontitis were examined. A comprehensive periodontal-orthodontic examination was performed. Exclusion criteria: age <30 years, removable prosthetics, uncontrolled diabetes, pregnancy/lactation, and oncologic disease. RESULTS: Class II malocclusion was found in 49.6% (Class II div 1-20.7%, Class II div 2-9.9%, subdivision Class II-19.0%), Class I-31.4%, Class III-10.7%, no malocclusion-8.3% of subjects. PTM was observed in 74.4% of maxillary and 60.3% of mandibular AT. Spacing and extrusion were the main types of PTM of AT. Odds ratio for PTM of maxillary AT was 9.3 in cases with >30% of sites with clinical attachment loss ≥5 mm (P = 0.001). Spacing of maxillary AT was influenced by periodontitis, Class III malocclusion, and lost teeth. Tongue habit had impact on spacing of mandibular AT. Dental Health Component of Index of Orthodontic Treatment Need yielded that OTN was found in >50% and OTN due PTM, occlusal trauma and impaired function in 66.1% of subjects. CONCLUSIONS: The most prevalent malocclusion was Class II. Spacing and extrusion were prevalent types of PTM of AT. OTN was found in more than half of the subjects. The study highlights the need for preventive measures for PTM in subjects with stage III-IV periodontitis.

Impact of temperature changes to the adhesion strength of molar tubes: an in vitro study.

BACKGROUND: The main purpose of this was to determine study adhesion strength of molar tubes bonding with a composite adhesive after exposure to a sudden change in temperature (thermal cycles). METHODS: The study sample consisted of 40 recently extracted human first permanent molars, which were randomly divided into two groups of 20: group 1 was the experimental group (affected by thermal cycles), and group 2 was the control group. Molar tubes were bonded with a light-cure tube adhesive. The experimental group teeth were dipped 2,000 times in saline at 5 °C and at 55 °C. The control group were immersed in 37 °C saline. Molar tubes for both groups were removed with an adapted Mecmesim Multitesters 2.5-I, and the data were recorded with EMPEROR software. ANOVA was used to calculate and compare the results. RESULTS: In the experimental group of the teeth, the maximum force was obtained at 94.2 N and the lowest force was 19.69 N. In the control group of the teeth, the maximum force was obtained at 159.1 N and the lowest force was 28.1 N. In the experimental group, the mean debonding force (59.12 N) was statically significantly smaller than in the control group (79.88 N), p = 0.0345. The forces in the control group were by 1.35 times greater than those in the experimental group. CONCLUSIONS: The forces of the adhesion of molar tubes to the tooth surface were reduced after exposure to a sudden change in temperature (thermal cycles). The results were significantly different between the experimental group and the control group.

Facial asymmetry and chewing sides in twins.

OBJECTIVE: To resolve how the preferred chewing side (PCS) affects facial asymmetry in twins, whether there are differences between monozygotic (MZ) and dizygotic (DZ) twins, and whether the twins with PCS have more asymmetric faces compared to symmetrically chewing twins. MATERIAL AND METHODS: The study included 106 Lithuanian twin pairs of the same sex, 59 MZ and 47 DZ pairs. The data were analysed from facial 3D images and manually added landmarks. 3D images were analysed by Rapidform2006 software and statistical analyses were done by using the R software environment version 4.1.0. RESULTS: The contralateral effect of PCS and larger chin side was dominant among right and non-right side chewing twins. Being female increased the whole face symmetry. CONCLUSION: The volume of the chin becomes larger on the side opposite to the twins' habitual chewing side. As the results are quite similar in both twin types, functional factors are more prominent than heredity.

Reliability and Validity of a Lithuanian Version of the Oral Health Impact Profile-A Study in Patients with Stage III-IV Periodontitis.

Background and Objectives: The study aimed to translate the original English version of Oral Health Impact Profile (OHIP) into Lithuanian and to assess reliability and validity of the translated instrument (OHIP-Lt) in patients with advanced stages of periodontitis. Materials and Methods: Subjects (N = 67) with stage III-IV periodontitis aged 30-63 years were surveyed by questionnaire and examined clinically. Psychometric analysis included explanatory (EFA) and confirmatory (CFA) factor analyses and psychometric tests. Results: Cronbach's alpha of the translated OHIP was 0.96. EFA revealed four dimensions which Cronbach's alpha ranged from 0.75 to 0.96. Construct validity of the four-factor model derived from the OHIP-Lt was supported by findings of CFA (RMSEA = 0.077). The total OHIP-Lt and its subscale scores increased as the patients' self-rated oral health status changed from healthy to unhealthy. Discriminative validity of the OHIP-Lt was confirmed by its higher scores among patients who had an increased spacing between the maxillary anterior teeth and increased clinical attachment level (CAL ≥ 5 mm) compared to those who did not. Conclusions: The translated Lithuanian version of OHIP-Lt was identified as four-dimension inventory. Good reliability and validity of the OHIP-Lt provide the evidence for its further use in study on advanced periodontal disease burden among Lithuanian patients.

Relationships of Dental Caries and Malocclusion with Oral Health-Related Quality of Life in Lithuanian Adolescents Aged 15 to 18 Years: A Cross-Sectional Study.

There is a lack of evidence of the moderating effects of caries lesions and malocclusions on oral health-related quality of life (OHRQoL) among older adolescents. This study aimed to evaluate the relationship of dental caries and malocclusion with OHRQoL among Lithuanian adolescents aged 15 to 18 years. A survey in a representative sample of adolescents included a clinical examination to assess dental health status using the DMFT (Decayed, Missing, and Filled Permanent Teeth) index, and malocclusion using the Index of Complexity, Outcome, and Need (ICON). The Child Perceptions Questionnaire (CPQ) was used to evaluate respondents' OHRQoL. Negative binomial regression was fitted to associate the clinical variables with the CPQ scores. A total of 600 adolescents were examined. The overall mean DMFT score was 2.7. A need for orthodontic treatment was detected among 27.7% of adolescents. Subjects with caries lesions (DMFT > 3) had higher CPQ scores in the domains of functional limitations and social wellbeing (relative risks were 1.35 (95% confidence interval: 1.09-1.67) and 1.30 (1.03-1.64), respectively), while subjects with a need for orthodontic treatment (ICON > 43) had higher CPQ scores in the domains of emotional wellbeing and social wellbeing (relative risks were 1.81 (1.40-2.22), and 1.69 (1.34-2.14), respectively). It was concluded that both dental caries and malocclusion have negative relationships with OHRQoL in adolescents above 15 years, but their effects occur differently in each OHRQoL domain.

Family Affluence Based Inequality in Oral Health-Related Quality of Life in a Population of Lithuanian Adolescents.

BACKGROUND: The social inequalities in oral health have had increasing attention in recent years. The present study aimed to explore the impact of family affluence on Oral Health-Related Quality of Life (OHRQoL) among Lithuanian adolescents aged 11-18 years. METHODS: The cross-sectional, population-based study included a representative sample of 881 adolescents aged 11-18 years (mean = 15.55; SD = 1.51) randomly selected from 20 schools in Lithuania. The schoolchildren completed questionnaires to evaluate their OHRQoL using a Lithuanian version of the Child Perceptions Questionnaire (CPQ). The adolescents' family affluence was indirectly assessed by inquiring whether they possessed various modern life items. In dental examination, the severity of malocclusion was predetermined by the Index of Complexity, Outcome, and Need (ICON). The relationship among variables was examined employing the negative binomial regression and the path analysis. RESULTS: The sum score of CPQ as a whole and the sum scores of all four domains were significantly associated with family affluence, indicating higher OHRQoL among adolescents from more affluent families. The severity of malocclusion had a significant association with emotional and social well-being domains of OHRQoL only. CONCLUSION: This study evidences the family affluence based inequality in OHRQoL among Lithuanian adolescents.

Impact of Fluorosis on the Tensile Bond Strength of Metal Brackets and the Prevalence of Enamel Microcracks.

The objective of this in vitro study was to determine the effects of dental fluorosis on the tensile bond strength of metal brackets bonded to human teeth and to evaluate the changes in the tooth enamel surface after debonding. The study sample consisted of 68 recently extracted human upper premolars, which were divided into 2 groups: the fluorosis group (34 fluorosed teeth) and the control group (34 healthy teeth). Identical premolar metal brackets were bonded on the buccal surfaces of the teeth. Both groups were submitted to a tension test using a universal testing machine. The number and length of the enamel microcracks in the buccal surface of each tooth were determined before bracket bonding and after debonding using a stereomicroscope. The percentage adhesive remnant index (PARI) was calculated after debonding. The results showed that the tensile bond strength (TBS) of brackets bonded to fluorosed teeth was 21.08% lower than that of brackets bonded to healthy teeth (p < 0.0001). The length of the enamel microcracks on fluorosed teeth increased by 47.4% after debonding, whereas the control group showed an increase of only 12.6%. The PARI showed lower values for fluorosed teeth in comparison to the control group (p = 0.047). In conclusion, dental fluorosis has a negative impact on tensile bond strength and the length of microcracks formed after bracket debonding.

Modification and psychometric evaluation of the child perceptions questionnaire (CPQ11-14) in assessing oral health related quality of life among Lithuanian children.

BACKGROUND: Oral health related quality of life (OHRQoL) research among children and adolescents in Lithuania is just starting and no measures have been validated to date. Therefore, this study aimed to validate a Lithuanian version of the full (37 items) Child Perceptions Questionnaire (CPQ11-14) within a random sample of children aged 11 to 14. METHODS: A cross-sectional survey among a randomly selected sample of schoolchildren (N = 307) aged 11 to14 was conducted. An anonymous questionnaire included the full CPQ11-14 and items on global life satisfaction, oral health and oral life quality self-rating. The questionnaire was translated into Lithuanian using translation guidelines. In addition, an item on the oral pain was modified identifying the pain location. Standard tests (Cronbach's α, construct validity and discriminant validity), supplemented with both exploratory and confirmatory factor analyses, were employed for psychometric evaluation of the instrument. The questionnaire was also tested by comparison students' and their parents' (N = 255) responses about oral symptoms and functional limitations. RESULTS: The modified Lithuanian version of CPQ11-14 revealed good internal consistency reliability (Cronbach's alpha for the total scale was 0.88). The measure showed significant associations with perceived oral health status and oral well-being, as well as with global life satisfaction (p < 0.01). Discriminant validity of the instrument was approved by comparison of children's groups defined by self-reported caries experience and malocclusion. Factor analysis revealed a complex structure with two or three factors in each of four domains of the CPQ11-14. Excellent or acceptable levels of indices of model fitting with the given data were obtained for oral symptoms, functional limitations and emotional well-being domains, but not for the social well-being domain. A significant association between child and parental responses was found (intraclass correlation coefficient was 0.56 and 0.43, correspondingly in domains of oral symptoms and functional limitations). CONCLUSION: The Lithuanian version of the CPQ11-14 (with a modified item that identifies location of oral pain) appears to be a valid instrument to be used in further studies for measuring OHRQoL among 11 to 14 year old children in Lithuania.

Relations of laterality and chewing sidedness in twins.

OBJECTIVES: To study, whether there are associations between chewing side preference and other lateralities, whether there is a genetic origin for preferred chewing side (PCS), relations to sex, birth order and orthodontic treatment. MATERIALS AND METHODS: The study included 113 twin pairs, 57 pairs monozygotic, 47 pairs same sex dizygotic and 9 pairs of opposite sex. The lateralities of preferred chewing side, footedness and eyedness were assessed by functional tests and handedness was checked by asking. RESULTS: Right-handed, -footed and -eyed as separated groups, and true-right sided (combined), were evenly distributed by preferred chewing side. By contrast, left-handed, -footed, -eyed and non-right sided used more left or both sides when chewing. Birth order affected preferred chewing side among monozygotic: the first-born twin was more likely to have the preferred chewing side on the non-right, whereas second-born twins used right side. Gender, zygosity and orthodontic treatment were not statistically significant factors. LIMITATIONS: Examination of chewing sidedness could have been done in several different ways to provide a definite result. Sample size of opposite sex twins was very small. CONCLUSIONS: Preferred chewing side generally seemed to follow the side where other lateralities occur; however, monozygotic twins seemed to be more receptive to it. True-right sided were more evenly distributed than non-right sided by the preferred chewing side.

Genetic and environmental influences on third molar root mineralization.

OBJECTIVE: To assess the genetic and environmental influences on the variability of human third molar (M3) root mineralization stages via a twin study. DESIGN: The study sample consisted of 162 same-sex twins (66 dizygotic and 96 monozygotic, mean age: 17.9 years) with normal growth and development. Panoramic radiographs were evaluated to assess root mineralization stages of the upper and lower third molars, using the method of Demirijian et al. (1973). Zygosity was established using 15 specific DNA markers. RESULTS: Females developed their third molar roots earlier in life than males. Monozygotic twins (MZ) demonstrated higher intra-pair correlations for M3 root development stages than did DZ twins. An ACE model with additive genes, as well as common and specific environmental factors, provided the best explanation of variation in M3 root development. The mineralization of M3 roots showed highly additive genetic determination, varying from 60 to 63%, whereas a common environment contributed from 25 to 27%, and a specific environment only accounted 14% of the total variation, at most. CONCLUSIONS: A considerable proportion of the total variability of the third molar root mineralization rate can be attributed to additive genetic effects, while common and specific environmental effects have a smaller, yet significant, impact.

Smile aesthetics as perceived by dental students: a cross-sectional study.

BACKGROUND: An aesthetic smile has a number of components, and people generally equate a good dental appearance with success in many areas of life. The features that determine smile aesthetics could provide significant insights into post-treatment satisfaction and may predict a patient's objectives when undergoing treatment. The purpose of this study was to evaluate how smile characteristics are perceived by dental students. METHODS: The study was performed in 431 local and international dental students at the Lithuanian University of Health Sciences. The study data were collected using a three-part questionnaire. The first part of the questionnaire included sociodemographic items, i.e., student gender, age, nationality, and years of study; the second consisted of questions about facial aesthetic features; and the third elicited responses to photographs of 17 different smiles retrieved from the Lithuanian University of Health Sciences Clinic of Orthodontics database. The smile aesthetics were evaluated according to their dentolabial, dentogingival, dental, and dental arch characteristics using a 5-point numeric rating scale (1, best; 5, worst). The data were analysed using the Pearson's chi-square and Mann-Whitney U tests. RESULTS: The study included 336 local and 95 international dental students (132 men [30.6%], 299 women [69.4%]). Significantly more women than men focused on a person's teeth when communicating (41.5% vs.32.6%, p < 0.005). Women were more critical than men when evaluating gingival smile, the 'golden proportion', occlusal cant, and dental crowding. The most unfavourable smile characteristics were identified in the dental analysis category, with hypodontia ranked as the worst smile feature (mean numeric rating scale score 4.71). CONCLUSION: Among dental students, the most distracting characteristics of a smile when determining its attractiveness were hypodontia, gingival smile, a reversed curvature of the occlusal plane, and dental crowding.

The Impact of Genetics and Environmental Factors on the Position of the Upper Third Molars.

PURPOSE: The purpose of this study was to estimate the importance of heredity in the position of the upper third molars. MATERIALS AND METHODS: Panoramic radiographs and lateral cephalograms of same-gender twins were analyzed. The determination of zygosity was performed by means of DNA tests with polymerase chain reaction for the amplification of short tandem repeats and 15 specific DNA markers. Data were estimated by the relative influence of additive genetic factors (A), nonadditive genetic factors (D), the common or shared environment (C), and unique environmental factors (E). RESULTS: The study sample consisted of 212 twins: 80 dizygotic and 132 monozygotic twins. The genetic analysis showed that the best-fitting model for the size of the molars and their angulations was AE (additive genetic factors and unique environmental factors), in which the additive genetic factors had up to 84% influence and specific environment had up to 40%. Therefore, the ACE (additive genetic factors, common or shared environment, and unique environmental factors) model showed higher significance for the tooth eruption level. The heritability estimates were up to 59%, specific environment contributed up to 16%, and common environment reached 30%. CONCLUSIONS: Genetic factors play a key role in the position of the upper third molars.

Impact of genetics on third molar agenesis.

The purpose of this investigation was to determine the impact of heritability on third molar agenesis in twins. The study sample consisted of 284 same sex twins (172 monozygotic and 112 dizygotic), whose mean ages were 19.7 ± 4.3 and 18.9 ± 4.8 years, respectively. The monozygotic group consisted of 36.3% males and 63.7% females, while the dizygotic group consisted of 50.1% males and 49.9% females. The zygosity of the twins was established using 15 specific DNA markers. The prevalence of third molar agenesis in monozygotic twins was 19.6%, which was higher than in the dizygotic twins group (15.50%) (p = 0.004). In both groups, third molar agenesis was more frequent in the maxilla than in the mandible (p = 0.000). Agenesis of the maxillary third molars was mostly affected by additive genetic factors (62-63%), with the common environment and the specific environment accounting for up to 25% and 13%, respectively. In contrast, agenesis of the lower third molars was associated with a higher additive genetic determination (81-83%), with the specific environment accounting for 17% to 19%. The study's conclusion is that the formation of the third molars follicle is strongly controlled by additive genetic factors.

Relationship Between Orthodontic Treatment Need and Oral Health-Related Quality of Life among 11⁻18-Year-Old Adolescents in Lithuania.

The aim was to examine the relationship between orthodontic treatment need and Oral Health-Related Quality of Life (OHRQoL) among Lithuanian adolescents aged 11⁻18 across gender and age groups. A representative cross-sectional study of 911 adolescents aged 11⁻18 (mean (M) = 15.53; Standard Deviation (SD) = 1.52) was conducted in 26 public schools. The schoolchildren completed the Child Perceptions Questionnaire to evaluate their OHRQoL. The Index of Orthodontic Treatment Need (IOTN) was used to evaluate the severity of malocclusion. The strength of association between variables was evaluated via negative binomial regression estimating the ratio of sum score means (RSSM). A worse OHRQoL score was associated with a higher grade of IOTN; however, only the Emotional and Social wellbeing domains were significantly affected by malocclusion (RSSM = 1.158; 95% Confidence Interval (CI): 1.083⁻1.237 and RSSM = 1.205; 95% CI: 1.114⁻1.304, respectively). The significant association was identified only among females (RSSM = 1.264; 95% CI: 1.176⁻1.359). A significant association was observed in all age groups for Emotional and Social well-being domains but only in the oldest age group for Oral Symptoms and Functional Limitations domains. CONCLUSIONS: Malocclusion has a negative impact on the OHRQoL of young people with emotional and social aspects being the most affected. Girls and older adolescents suffered from malocclusion more than boys and their younger counterparts.

The magnification in the lower third and second molar region in the digital panoramic radiographs.

BACKGROUND: The aim of this study was to determine the accuracy of linear measurements of the lower third and second molar crowns in the digital panoramic radiographs and to compare them with plaster models as the calibration standard. MATERIALS AND METHODS: The digital panoramic radiographs and plaster models of the orthodontic patients were used in the study. Standardized metal calibration gauges (MCGs) were bonded to the buccal surface of the lower molars bilaterally. Measurements in the panoramic radiographs were done using Dolphin Imaging 11.8 Premium program. RESULTS: Forty-one panoramic radiographs and diagnostic plaster models of the orthodontic patients (mean age 18.45 ± 2.35) were analyzed. Eighty-two lower third molars, 82 second molars, and 82 first molars were evaluated. The magnification coefficients (MCC) calculated according to the plaster models ranged from 1.07 to 1.08. The magnification coefficients calculated according to the bonded MCG were about 1.04. The differences between the teeth groups and right-left sides were not statistically significant (P > 0.05). Spearman correlation showed a positive medium correlation between the magnification using the calibration with plaster models and metal gauges (P < 0.05). CONCLUSIONS: The magnification in the lower first, second, and third molars regions showed almost the same values. The calculation of magnification coefficient using bonded metal calipers was more accurate than calculation according to the plaster models, but the differences were not statistically significant. The use of the plaster models for calibration of the magnification coefficient in the good-positioned lower molars' region might be used as an alternative to the bonded MCGs.

Association between Global Life Satisfaction and Self-Rated Oral Health Conditions among Adolescents in Lithuania.

Background: This study aims to explore the extent to which the perceived oral conditions predict adolescent global life satisfaction (GLS); Methods: The sample in a cross-sectional survey consisted of 1510 Lithuanian adolescents (41.7% boys) aged 11-18. The survey was conducted by means of self-report questionnaires that were administrated in school classrooms ensuring confidentiality and anonymity of the participants. The schoolchildren rated their GLS and answered the questions about perceptions of their oral health. The relationship between GLS and oral health variables was estimated using unadjusted and adjusted binary logistic regression and nonparametric correlation analyses; Results: The research showed that the majority of adolescents rated their GLS highly; however, girls, older adolescents and adolescents from less affluent families were less likely to report high scores. GLS was significantly associated with subjective overall oral health assessment. The odds of reporting low GLS were 50% higher for adolescents with good oral health (OR = 1.51; p < 0.001; 95% CI = 1.18-1.93), and two and half time as higher for adolescents with perceived fair/poor oral health (OR = 2.78; p < 0.001; 95% CI = 1.72-4.50) compared to adolescents with subjectively excellent/very good oral health. Nonparametric correlations indicated lower GLS to be significantly associated with higher scores of Child Perceptions Questionnaire (.

A survey of protocols and trends in orthodontic retention.

BACKGROUND: The objectives of this study were to evaluate retention procedures and protocols which are used by the orthodontists in Lithuania and to identify commonly used types of dental retainers. METHODS: One hundred seven questionnaires in total with 28 multiple-choice questions were sent to all members of the Lithuanian Orthodontic Society. The questionnaire was organized into eight sections representing specific information about socio-demographic status of the respondents, selection of a retention system, details of commonly used fixed and removable retainers, the duration of the retention period, supervision of the retainers, instructions for patients, and necessity of common retention guidelines. RESULTS: The overall response rate was 75.7%. All of the respondents prescribed retainers after the orthodontic therapy. More than 40% of the respondents combined fixed and removable retainers in different clinical situations, but the first-choice option after an expansion of the maxillary dental arch was the removable retainer (54.3%); meanwhile, a fixed retainer was used after a correction of any rotations of the mandibular anterior teeth (49.4%). The Hawley retainer was preferred by 90.1% of the respondents for a maxillary dental arch, and 74.1% of them preferred it for a mandibular dental arch. The most preferable fixed retainer was the retainer bonded to all six anterior teeth (in the upper dental arch-by 71.6%; in the lower one-by 80.2%). There was no consensus on the duration of a retention period. Most of the orthodontists checked up retainers three times during the first year (fixed ones-by 42.0%; removable ones-by 30.0%) and once per year after the 1-year retention period (fixed ones-by 44.4%; removable ones-by 40.7%). All orthodontists gave instructions for taking care of an orthodontic retainer. It was observed that the orthodontists with less than 10 years of experience used a protocol based on the skills learned during their postgraduate studies, while orthodontists with more than 10 years of experience used retention procedures based on their orthodontic work practice (p < 0.05). CONCLUSIONS: A combination of fixed and removable retainers was the most often used in an orthodontic retention. Evidence-based guidelines are desired for a common retention protocol.

Effect of Rebonding on the Bond Strength of Orthodontic Tubes: A Comparison of Light Cure Adhesive and Resin-Modified Glass Ionomer Cement In Vitro.

The purpose of this study was to determine the impact of different enamel preparation procedures and compare light cure composite (LCC) and resin-modified glass ionomer (RMGI) on the bond strength of orthodontic metal tubes rebonded to the enamel. Twenty human molars were divided into two groups (n = 10). Tubes were bonded using LCC (Transbond XT) in group 1 and RMGI (Fuji Ortho LC) in group 2. The tubes in each group were bonded following manufacturers' instructions (experiment I) and then debonded using testing machine. Then, the same brackets were sandblasted and rebonded twice. Before the first rebonding, the enamel was cleaned using carbide bur (experiment II) and before second rebonding, it was cleaned using carbide bur and soda blasted (experiment III). Mann-Whitney and Wilcoxon signed-rank tests showed no significant difference between RMGI and LCC bond strengths in case of normal bonding and rebonding, when enamel was cleaned using carbide bur before rebonding. Enamel soda blasting before rebonding significantly increased RMGI tensile bond strength value compared to LLC (p < 0.05). LCC and RMGI (especially RMGI) provide sufficient bond strengths for rebonding of molar tubes, when residual adhesive from previous bonding is removed and enamel soda blasted.