Assessment of Tooth Shade Measurement Precision and Consistency with Digital Photography Calibration System.

Objectives: To ascertain the degree of precision and repeatability inherent in the "capture to edit" digital imaging system, namely the ColorChecker Passport Photo (X-Rite, MI, USA), and to juxtapose its performance against spectrophotometric assessments utilizing the Vita Easyshade® (Vita Zahnfabrik, H Rauter GmbH & Co. KG., Bad Sackingen, Germany) for the same set of teeth. Materials and methods: Eighty participants aged 19-25 were included in the study; all of them were Croatian students at the School of Dental Medicine, University of Zagreb. Color measurements of the maxillary right central incisors were performed in controlled, standardized laboratory conditions. The measurements were performed on calibrated digital photographs by an experienced clinician three times in a row, and L, a, and b of CIELAB color space values were recorded. The same procedure was performed using the Vita Easyshade 5.0 spectrophotometer (Vita Zahnfabrik, Bad Säckingen, Germany) in "Tooth single" mode. Results: The Cronbach's alpha was used as a repeatability measurement, thus revealing high consistency for both methods (α=0.94-1). Correlations were moderate (Pearson r=0.44-0.66 p<0.05). Testing confirmed that digital photography is inaccurate as spectrophotometry (p<0.05). An analysis of errors of means and their standard deviations revealed consistent discrepancies with minor deviations. Conclusion: The "capture to edit" method showed high consistency (Cronbach's α=0.94-0.96), and it exhibits comparability in terms of variability, reliability, and repeatability when compared to spectrophotometric measurement (VitaShade 5, VitaZahnfabrik). Disparities between the methods are evident and anticipated, yet they do not follow a consistently linear pattern. The combination of repeatability and consistency renders the "capture to edit" method a valuable tool for enhanced color mapping, thus facilitating comparisons between digital images.

Comparison of Tooth Size Measurements in Orthodontics Using Conventional and 3D Digital Study Models.

(1) Background: The objective of this study was to assess which digitization method produces the biggest deviation in the 3D images of tooth size from plaster models made using alginate impressions, which are considered the gold standard in orthodontics. (2) Methods: The sample used in this study included 30 subjects (10 males and 20 females). Measurements were made on four types of models: (1) digital models obtained through intraoral scanning and digitized models of plaster cast made from (2) alginate impressions, (3) silicone impressions, and (4) conventional plaster models. Mesio-distal (MD) and buccal/labial-lingual/palatal (BL) dimensions were measured on the reference teeth of the right side of the jaw (central incisor, canine, first premolar, and first molar). Comparisons of tooth size between the methods were conducted using a repeated measurement analysis of variance and the Friedman test, while the intraclass correlation coefficient was used to determine agreement between the different methods. (3) Results: The results showed a similar level of agreement between the conventional and digital models in both jaws and the anterior, middle, and posterior segments. Better agreement was found for the MD measurements (r = 0.337-0.798; p ≤ 0.05) compared to the BL measurements (r = 0.016-0.542), with a smaller mean difference for MD (0.001-0.50 mm) compared to BL (0.02-1.48 mm) and a smaller measurement error for MD (0.20-0.39) compared to BL (0.38-0.89). There was more frequently a better level of agreement between 3D images than measurements made using a digital caliper on the plaster models with 3D images. (4) Conclusions: The differences in measurements between the digital models and conventional plaster models were small and clinically acceptable.

Parental influence is the most important predictor of child's orthodontic treatment demand in a preadolescent age.

The aim was to explore the predictive value of objective treatment need, impaired quality of life, and parental influence on orthodontic treatment demand in preadolescents and adolescents. A secondary goal was to validate 16-item Child Perceptions Questionnaire for the 11-14 year age group (CPQ11-14): item-impact and stepwise-regression short-forms. A convenience sample of 287 participants (55% female) was used for validation. Internal consistency, test-retest reliability, and convergent validity were evaluated. Predictors of treatment demand were explored in 197 orthodontic patients: 93 preadolescents (51% females), 104 adolescents (55% females). Hierarchical linear regression and multilevel logistic regression models were used to explore the predictive power of age, gender, objective treatment need, impaired quality of life and parental influence on treatment demand. CPQ11-14 regression short-form had acceptable psychometric properties. Significant linear predictors of treatment demand were impaired emotional well-being (EW) (ß = 0.335, p = 0.002), parental influence (ß = 0.221, p = 0.002), and malocclusion severity (ß = 0.152, p = 0.025). In logistic regression, parental influence was revealed as the most important predictor of treatment demand in preadolescents, OR = 7.7 (95% confidence interval CI 2.4-25.1; p = 0.001); objective treatment need in adolescents, OR = 4.5 (95% CI 1.5-12.9; p = 0.006). The increase of impairment in EW by one scalar point increased treatment demand by 1.4 (95% CI 1.1-1.9; p = 0.017) in preadolescents; 1.3 (95% CI 1.0-1.7; p = 0.021) in adolescents. Greater parental agreement and motivation for treatment could result in higher preadolescents' cooperation. Orthodontic treatment in adolescents might be more effective with the patient-oriented approach.

Child Perceptions Questionnaire in Croatia: Two Domains for Measuring Oral Health.

OBJECTIVE: To perform cross-cultural adaptation and to test psychometric properties of the 8-item CPQ in 11-14 year-olds: stepwise-regression (RSF:8) and item-impact (ISF:8) short-forms. MATERIALS AND METHODS: The sample included 237 orthodontic patients aged 11-14 at two University Dental Clinics in Croatia. Structural and construct validity, reliability and responsiveness were assessed. Intraoral examination included an assessment of dental caries and malocclusion severity. RESULTS: Two domains instead of originally suggested four are more appropriate for the assessment of oral health-related quality of life (OHRQoL) in both ISF:8 and RSF:8 (60.05% and 52.24% variance; α=0.56-0.85). Oral symptoms and functional limitations from the original instrument were grouped in one dimension that defines oral function, while emotional and social well-being was grouped in a dimension of psychosocial well-being. Instruments are able to detect differences between subjects with low and high caries and malocclusion severity. They were stable when there were no changes in oral conditions, while it was possible to detect differences induced by correction of malocclusion following orthodontic treatment (p<0.05). CONCLUSION: A 8-item CPQ demonstrated good psychometric properties but points to the fact that two domains instead of four are more appropriate for the assessment of OHRQoL in 11-14 year-olds.

Correlation between the DAI and ICON Indices used for Assessment of Orthodontic Treatment need in Croatian Schoolchildren.

INTRODUCTION: The aims were: evaluation of the correlation between the Dental Aesthetic Index (DAI) and Index of Complexity, Outcome and Need (ICON); the assessment of orthodontic treatment need for schoolchildren in a population with two indices, separately for schoolchildren with mixed and permanent dentition; the estimation of the population share that could not receive orthodontic treatment because of the presence of caries and/or gingivitis. METHODS: A total of 2652 Zagreb school children (7 - 19 years old, 52.4% of them were females) completed a questionnaire regarding previous orthodontic treatment and the type of appliance used. Their oral cavity was also inspected. The DAI and ICON indices were used for the assessment of malocclusion prevalence. RESULTS: The subjects with mixed dentition had a greater need for orthodontic treatment, when compared to subjects with permanent dentition, when using the DAI index (p<0.001). When using the ICON index, 11.7% of subjects with mixed dentition had very severe malocclusion, as opposed to 5.8% of subjects with permanent dentition. The DAI and ICON scores correlated positively linearly (r=0.521; p<0.001). A higher prevalence of both gingivitis and caries was recorded more often in boys; caries more often in the group with the mixed dentition, and gingivitis in the group with permanent dentition (p<0.05). CONCLUSION: The DAI and ICON indices have moderate agreement in assessment of malocclusion severity scores. One third of all schoolchildren with various degrees of both ICON and DAI indices have gingivitis, and half of them have caries.

Comparison of Shear Bond Strength of Orthodontic Brackets Using Direct and Indirect Bonding Methods in Vitro and in Vivo.

AIM: Aim of article was to compare the shear bond strength of indirectly and directly bonded orthodontic brackets. MATERIALS AND METHODS: The experimental in vitro study included 60 maxillary and mandibular premolars. Teeth were mounted on cold-cure acrylic blocks for each tooth separately and divided into two groups: directly bonded brackets (30 teeth) and indirectly bonded brackets (30 teeth). Brackets (Discovery, Roth 0.022", Dentaurum, Ispringen, Germany) were bonded using Transbond XT (3M Unitek, Monrovia, CA, USA) in direct method, while in indirect technique, a combination of Transbond XT and Sondhi Rapid Set (3M Unitek, Monrovia, CA, USA) was used. The shear bond strength and adhesive remnant index (ARI) were evaluated. The in vivo study included 30 subjects - 15 with indirectly bonded brackets and 15 with directly bonded brackets. Survival rate was assessed during the period of 6 months. RESULTS: No statistically significant difference in the shear bond strength was found in direct (7.48±1.61 MPa) and indirect labial bonding methods (7.8.2±1.61 MPa). Both methods produced very similar amount of adhesive remnant on tooth surface (median = 1; interquartile range 1-2). There were no significant differences in bracket survival rate between methods. CONCLUSION: Regarding the shear bond strength, adhesive remnant on tooth surface, and survival rate, both indirect and direct methods of orthodontic bracket bonding seem to be equally valuable methods in clinical practice.

Fluctuating Dental Arch Asymmetry in Different Malocclusion Groups.

OBJECTIVE: To compare the degree of dental arch fluctuating asymmetry (FA) among patients with Class I, II, and III malocclusions. SUBJECTS AND METHODS: The sample comprised randomly selected plaster casts of 131 patients: 39 Class I (19 males and 20 females), 57 Class II (23 males and 34 females), and 35 Class III (20 males and 15 females). Dental models were scanned and digitized using ATOS II SO. The measurements of the teeth and dental arches were taken using the ATOS viewer version 6.A.2 software. Six arch widths and five arch depths were measured. The FA was assessed as a composite index of total weighted asymmetry (TWA). The analysis of variance was used to determine whether there were any statistically significant differences between the groups. RESULTS: Composite TWA measures of fluctuating asymmetry for dental arch variables were the highest in Class III, and lowest in Class I malocclusion. Males displayed a higher degree of asymmetry than females. The asymmetry degree was higher in the mandibular dental arches than in the maxillary dental arches in all malocclusion groups. CONCLUSION: The TWA values were low but they differed significantly between the groups of malocclusion. Class III malocclusion displayed higher FA values than Class I and Class II malocclusion. Higher FA of dental arches in Angle's Class III can be considered an indicator of increased developmental instability in this malocclusion due to high levels of genetic and environmental stress during the period of early development.

Dental and General Trauma in Team Handball.

Handball has developed into a much faster and high-impact sport over the past few years because of rule changes. Fast sports with close body contact are especially prone to orofacial trauma. Handball belongs to a category of sports with medium risk for dental trauma. Even so, there is only little literature on this subject. The aim of this study was to examine the prevalence and the type of injuries, especially the occurrence of orofacial trauma, habits of wearing mouthguards, as well as degree of familiarity with the tooth rescue box. For this purpose, 77.1% (n=542/703) of all top athletes and coaches from the two highest Swiss leagues (National League A and National League B), namely 507 professional players and 35 coaches, were personally interviewed using a standardized questionnaire. 19.7% (n=100/507) of the players experienced dental trauma in their handball careers, with 40.8% (n=51/125) crown fractures being the most frequent by far. In spite of the relatively high risk of lip or dental trauma, only 5.7% (n=29/507) of the players wear mouthguards. The results of this study show that dental trauma is common among Swiss handball players. In spite of the high risk of dental trauma, the mouthguard as prevention is not adequately known, and correct procedure following dental trauma is rarely known at all.

History of Orthodontic Treatment, Treatment Needs and Influencing Factors in Adolescents in Croatia.

AIM: The aim of this study was to assess the orthodontic treatment needs of adolescents in Zagreb, Croatia, in relation to their orthodontic treatment history, caries experience and socio-demographic parameters. METHODS: The study sample comprised 1,289 adolescents from 12 randomly selected public schools in Zagreb, Croatia. The subjects were 15-18 years old (mean age 16.3±1.4), and 51% of them were girls. The Dental Aesthetic Index (DAI), the sum of the numbers of decayed, missing and filled teeth (DMFT index), and a questionnaire (covering socio-demographic issues, oral health-related attitudes and behaviours) were employed in this study. The data was analyzed by means of Chi-square test, analysis of variance, and multiple logistic regression models. RESULTS: The DMFT score was higher in adolescents with no orthodontic history (5.2±3.7) than in those who were under orthodontic treatment at the time of the research (4.5±3.2; p=0.043). More than 60% of the adolescents have never undergone any orthodontic treatment, around 24% previously undergone treatment and 15% were under treatment at the time of the research. Overall, 85% of the adolescents' orthodontic appliances were removable, and the girls were more often under orthodontic treatment. One fifth of the studied population had severe or very severe malocclusion. Adolescents with previous orthodontic treatment were more often interested in better teeth alignment, changes in their teeth positioning and continuing orthodontic treatment. Multiple logistic regression model demonstrated that previously treated adolescents, in comparison with their untreated peers, were on average older (p=0.002), were less satisfied with the appearance of their teeth (p=0.001), they had higher malocclusion severity (p=0.046), and fewer dental caries (p<0.001), changed toothbrushes more often (p=0.012), and their mothers attained higher education (p<0.001). CONCLUSIONS: Although many adolescents received orthodontic treatment, the severity of their malocclusion was still somewhat high, and they were more often dissatisfied with their treatment outcome. Mothers' educational level was found to be the most important socio-demographic predictor for children's involvement in orthodontic treatment. The caries experience increased in comparison with the Croatian national survey data from 1999.

Temporomandibular disorders and orthodontic treatment need in orthodontically untreated children and adolescents.

The aim of this study was to explore the association between signs and symptoms of temporomandibular disorders (TMD) and orthodontic treatment need in orthodontically untreated children and adolescents. One thousand five hundred and ninety-seven subjects aged 11-19 years, without previous orthodontic history, from sixteen randomly selected public schools in Zagreb, Croatia, were examined. Malocclusion characteristics were assessed by using the criteria proposed by Bjork et al., the Dental Aesthetic Index, and the Aesthetic Component of Index of Orthodontic Treatment Need. Data on TMD signs/symptoms and parafunctional behaviour were obtained by means of questionnaire and clinical examination, respectively. Multiple logistic regression models were used for analysis. Twenty-two percent of children and young adolescents had one or more signs of TMD, ranging from 17% in age of 11 years up to 24% in age of 19. There was poor correlation between presence of TMD and orthodontic treatment need. Multiple logistic regression models showed that Class III, crowding and spacing were related to mandibular deflection on opening. Ectopic eruption was related to TMJ clicking, and severely tipped teeth with reduced mouth opening. Headaches presented a positive relationship with reverse overjet and severe rotations, and tooth wear with crowding, spacing and lateral openbite. Age, female gender and parafunctional habits were related to several TMD signs. Although logistic regression models were statistically significant (p < 0.05) malocclusions, parafunctional behaviours, age and gender accounted for less than 20% of the variability in TMD signs/symptoms. TMD signs and symptoms seemed to be poorly related to malocclusions or treatment needs.

Factors influencing intensive care nurses' knowledge and attitudes regarding ventilator-associated pneumonia and oral care practice in intubated patients in Croatia.

Adequate oral care in intubated patients may reduce occurrence of ventilator-associated pneumonia. The purpose of this study was to explore knowledge, attitudes, and oral care practice in Croatian intensive care units and influencing factors. Nurses' knowledge is insufficient; however, most of them reported positive attitude toward the importance of oral care. Performed oral hygiene measures are mostly inappropriate. There is a need to improve the knowledge of ventilator-associated pneumonia and oral care.

The unmet orthodontic treatment need of adolescents and influencing factors for not seeking orthodontic therapy.

The purpose of this study was to estimate unmet orthodontic treatment needs of adolescents in Zagreb, Croatia, compare normative and self-perceived need and investigate factors influencing the reason why untreated subjects with severe malocclusions have not been treated before. One thousand and forty-two non-orthodontically treated subjects in age groups of 12 and 18 years, from sixteen randomly selected public schools in Zagreb, Croatia were examined. The Dental Aesthetic Index, Aesthetic Component of Index of Orthodontic Treatment Need and a questionnaire concerning self-perceived orthodontic treatment need, perception of aesthetics, function, behaviors and socioeconomic status were used. Around one third of untreated adolescent population had an objective need, less than 20 percent had aesthetic need, and self-perceived need was reported in one third of population. Associations and agreements between objective, aesthetic and self-perceived need were weak (r = 0.27-0.48; p < 0.001 and κ in range from 0.05 (p > 0.05) to 0.32 (p < 0.05), respectively). Satisfaction with personal dental appearance and awareness of malocclusion were better related in persons with no treatment need or minor need (r = 0.53-0.59) than in those with major need (r = 0.31-0.40). Multiple logistic regression analyses confirmed that objective, aesthetic and self-perceived needs were better related between themselves than to socio-economic status of subjects, function, activities of daily living and oral health-related behaviors. It appears that self-perceived treatment need has low role in predicting objective need, but relation between satisfaction and awareness of malocclusion could be one of basic factors in process of making decision to go for treatment and maybe could serve in predicting patient's compliance.

Clinical and microbiological parameters in patients with self-ligating and conventional brackets during early phase of orthodontic treatment.

OBJECTIVE: To determine the effect of different bracket designs (conventional brackets and self-ligating brackets) on periodontal clinical parameters and periodontal pathogens in subgingival plaque. MATERIAL AND METHODS: The following inclusion criteria were used: requirement of orthodontic treatment plan starting with alignment and leveling, good general health, healthy periodontium, no antibiotic therapy in the previous 6 months before the beginning of the study, and no smoking. The study sample totaled 38 patients (13 male, 25 female; mean age, 14.6 ± 2.0 years). Patients were divided into two groups with random distribution of brackets. Recording of clinical parameters was done before the placement of the orthodontic appliance (T0) and at 6 weeks (T1), 12 weeks (T2), and 18 weeks (T3) after full bonding of orthodontic appliances. Periodontal pathogens of subgingival microflora were detected at T3 using a commercially available polymerase chain reaction test (micro-Dent test) that contains probes for Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythia, and Treponema denticola. RESULTS: There was a statistically significant higher prevalence of A actinomycetemcomitans in patients with conventional brackets than in patients with self-ligating brackets, but there was no statistically significant difference for other putative periodontal pathogens. The two different types of brackets did not show statistically significant differences in periodontal clinical parameters. CONCLUSION: Bracket design does not seem to have a strong influence on periodontal clinical parameters and periodontal pathogens in subgingival plaque. The correlation between some periodontal pathogens and clinical periodontal parameters was weak.

Discriminant factor analysis of dental arch dimensions with 3-dimensional virtual models.

INTRODUCTION: The form and the size of a dental arch are products of the configuration and the naturally established balance of the jaw, alveolar bone, and muscles. We investigated which arch dimensions mostly discriminate particular dentoalveolar classes and sexes. METHODS: Plaster dental casts were collected from 137 white adolescent subjects (71 girls, 66 boys) aged between 15 and 18 years (mean, 16.0 ± 1.2 years) with Class I (43 subjects: 24 girls, 19 boys), Class II (50 subjects: 28 girls, 22 boys), and Class III (44 subjects: 19 girls, 25 boys) malocclusions. Casts were scanned with the ATOS II SO (small objects) scanner (GOM mbH, Braunschweig, Germany) and measured with ATOS Viewer software (version 6.0.2; GOM mbH). RESULTS: The major discriminating factors of the particular dentoalveolar classes are the mandibular canine width/depth ratio and the maxillary molar width/depth ratio, which explain 82.8% of the total variability (P <0.001). Class III subjects with the widest and shallowest frontal segment of the mandibular arch and the posterior segment of maxillary arch are clearly distinguished from Class II subjects whose abovementioned segments are the deepest and narrowest. Class I subjects are more similar to Class II than to Class III subjects. The most homogenous are Class III subjects, with 61.1% of them correctly classified, followed by Class II (57.8%) and Class I (52.4%). Sex differences are significant in linear measurements, but not in ratios. CONCLUSIONS: Variability of dental arch dimensions and forms is a common characteristic of all dentoalveolar classes. Maxillary arch form is more distinguishing in the posterior segment, and mandibular arch form is more distinguishing in the anterior segment. Class III patients have the most detectable arch form, and Class I the least detectable arch form.

Facial profile preferences: differences in the perception of children with and without orthodontic history.

INTRODUCTION: Improved facial esthetics can be fully achievable only if facial preferences of the treated group are known. We hypothesized that facial profile perception and preferences could be influenced by orthodontic treatment. METHODS: Differences in facial profile preferences between children with and without an orthodontic history were investigated in a sample of 1626 children aged 12 to 19 years (mean age, 14.8 ± 2.2 years) from 24 public schools in Zagreb, Croatia, randomly selected by using a cluster sampling procedure. Eight profile distortions for each sex, morphed by a digital imaging technique, were used for estimation. Analysis of variance (ANOVA), Bonferroni, and 2 independent sample t tests were used to compare the preferences of the groups. RESULTS: A straight profile was the most favored in both sexes, regardless of previous orthodontic history. A bimaxillary alveolar protrusive profile with thicker lips was preferred among the female profiles, and a bimaxillary retrusive profile with flat lips and a prominent chin was preferred among the male profiles. Orthodontic history and personal facial profile had little effect, and sex had a slightly greater influence on personal facial profile preferences. CONCLUSIONS: It seems that orthodontic therapy has no clinically relevant influence on facial profile preferences. Depending on the patient's sex, orthodontists should have different criteria for treating borderline patients with bimaxillary dentoalveolar protrusion and mandibular prognathism.

Dental archforms in dentoalveolar Class I, II and III.

OBJECTIVE: To test the hypothesis that no differences exist in dental arch dimensions between dentoalveolar Classes I, II, and III, and between male and female subjects, as measured on virtual three-dimensional (3D) models. MATERIALS AND METHODS: Samples included randomly selected plaster dental casts of 137 white patients (43 Class I, 50 Class II, and 44 Class III) from the Department of Orthodontics, School of Dental Medicine, University of Zagreb, Croatia. Dental models were scanned and digitized using ATOS II SO ("Small Objects") scanning technology (GOM mbH, Braunschweig, Germany). Eight linear and two proportional measurements were calculated for both upper and lower dental arches. RESULTS: In men, a significant difference in the upper dental arch was present in the incisor region, and in the lower dental arch, differences were found in intercanine and intermolar widths (P < .05). Significant differences were noted between male groups in the upper molar depth dimension (P = .022) and in the lower molar and canine depth dimensions (P < .05). Class III males had the greatest lower molar and canine width/depth ratios and the smallest lower canine depth/molar depth ratio. Class III women had wider and shorter mandibular arches when compared with Class I and Class II females. CONCLUSION: The hypothesis was rejected. The dimensions of the dental arches are related to gender and to dentoalveolar class. Class I and II subjects have similar dimensions of maxillary dental arch, but Class II subjects have a transverse deficit in the mandible. In Class III subjects, the maxillary dental arch is insufficient in transverse and sagittal dimensions, and the mandibular arch dominates in the transverse but not in the sagittal dimension.

Perception of orthodontic treatment need in children and adolescents.

SUMMARY: Patients' and parents' perception of malocclusion are important in determining orthodontic treatment demand, motivation, and cooperation. The aim of this study was to investigate differences in perception of treatment need in currently orthodontically treated, previously treated, and untreated subjects. The sample comprised 3196 children and adolescents (1593 males and 1603 females) aged 8-19 years (mean age 13.0 +/- 3.6 years) from 24 randomly selected public schools in Zagreb, Croatia. Objective treatment need was assessed clinically using the Dental Aesthetic Index (DAI). Subjective treatment need was estimated separately by an orthodontic resident, the child/adolescent and his/her parent using the Standardized Continuum of Aesthetic Need (SCAN) procedure. The children/adolescents completed a questionnaire that had five questions with five-point Likert-type scale answers concerning satisfaction with dental appearance, importance of teeth for facial appearance, and malocclusion-related quality of life. Spearman correlation and logistic regression were used for statistical analysis. Associations between objective and subjective orthodontic treatment need were weak but statistically significant (Rho from 0.20 to 0.50; P < 0.05). Malocclusion-related quality of life was poorly associated with treatment need. Satisfaction with tooth appearance showed the most frequent statistically significant correlation (Rho from -0.14 to -0.35; P < 0.05), while importance of aligned teeth for facial appearance and social contacts had the weakest correlation with treatment need. Perception of treatment need was greater in previously treated subjects. Parents' perception had a low predictive value. The findings of this study show that malocclusion has more impact on emotional well-being than on function or social contacts.

The reliability of chronological age determination by means of mandibular third molar development in subjects in Croatia.

The aim of this study was to determine the development of the mandibular third molar and its relation to chronological age. The evaluated material consisted of 979 orthopantomograms of patients of Croatian Caucasian origin aged between 5.7 and 14.6 years. Third molar developmental stages were evaluated according to the stages proposed by Nolla. The frequencies of different stages of mineralization and the mean value of the mineralization of the mandibular third molars with regard to age, gender, and size of the mandible were determined and the coefficient of correlation determined between the age of the subject and the stage of development of the mandibular molars. Statistically significant correlation was determined between mineralization of the mandibular third molar and chronological age of the subjects (boys, mandibular left third molar r = 0.779, right third molar r = 0.793; girls, mandibular left third molar r = 0.746, right third molar r = 0.725). It can be concluded that the accuracy of age estimation based on Nolla's method is applicable for Croatian children.

Type of archwire and level of acidity: effects on the release of metal ions from orthodontic appliances.

OBJECTIVE: To examine the effects of three different parameters-pH value, type of archwire, and length of immersion-on release of metal ions from orthodontic appliances. MATERIALS AND METHODS: Simulated fixed orthodontic appliances that corresponded to one-half of the maxillary arch were immersed in artificial saliva of different pH values (6.75 +/- 0.15 and 3.5 +/- 0.15) during a 28-day period. Three types of archwires were used: stainless steel (SS), nickel-titanium (NiTi), and thermo NiTi. The quantity of metal ions was determined with the use of a high-resolution mass spectrophotometer (HR-ICP/MS). RESULTS: The release of six different metal ions was observed: titanium (Ti), chromium (Cr), nickel (Ni), iron (Fe), copper (Cu), and zinc (Zn). Repeated measures statistical analysis of variance (ANOVA) was used. Results showed that (1) the appliances released measurable quantities of all ions examined; (2) the change in pH had a very strong effect (up to 100-fold) on the release of ions; and (3) the release of ions was dependent on wire composition, but it was not proportional to the content of metal in the wire. The largest number of ions was released during the first week of appliance immersion. CONCLUSION: Levels of released ions are sufficient to cause delayed allergic reactions. This must be taken into account when type of archwire is selected, especially in patients with hypersensitivity or compromised oral hygiene.

Presence of third molar germs in orthodontic patients with class II/2 and class III malocclusions.

The aim of this study was to determine the presence of third molar germs in patients with Class II/2 and Class III malocclusions. The study comprised 146 examinees from Zagreb and Istria. Examinees with Class II/2 malocclusions amounted to 77 and those with Class III 69. With regard to development of dentition the examinees were divided into two groups: Group I subjects with early mixed dentition (23 subjects with Class II/2 and 21 subjects with Class III), and Group II subjects with late mixed dentition (54 subjects with Class II/2 and 48 subjects with Class III). Assessments were made from panoramic radiographs and lateral cephalograms. The Pearson chi2-test and Fisher's exact test was used to determine statistical significance in differences. Assessments showed that third molar germs were present significantly more often in the upper jaw in Class II/2 (58% vs. 44%) and in the lower jaw in Class III (83% vs. 69%). In subjects with Class II/2 all third molar germs were present statistically more often in late mixed dentition, which was also determined for maxillary third molar germs in Class III. The presence of mandibular third molar germs in Class III examinees was almost equal in both periods of mixed dentitions. The study confirmed correlation between the presence of third molar germs and sagital maxillomandibular relationship and encourages investigation of the differences in calcifications of all permanent teeth in such malocclusions.