Anterior teeth root inclination prediction derived from digital models : a comparative study of plaster study casts and CBCT images

To assess the accuracy of digital models generated using commercially available software to predict anterior teeth root inclination characteristics and compare the results to relevant data obtained from CBCT images. Following sample size calculation and after application of inclusion and exclusion criteria, pre-treatment maxillary and mandibular plaster models and the corresponding CBCT scans of 31 patients attending a private orthodontic clinic were selected. The subjects were 10 males and 21 females with age range 12 to 40 years. Plaster models were scanned using the high resolution mode of an Ortho Insight 3D scanner and CBCT scans were taken using a Kodak 9500 Cone Beam 3D System machine. The teeth on the digital scans were segmented and virtual roots were predicted and constructed by the Ortho Insight 3D software. The long axes of the predicted roots and the actual roots, as segmented from the CBCT images, were computed using best-fit lines. The inter-axis angle was used to assess error in root inclination prediction by the software. Mann-Whitney and Kruskal-Wallis tests were used. Intra-examiner error was evaluated using the Bland-Altman method. The maximum disparity in angle between images derived from digital models and CBCT data was almost 40 degrees (upper left canine). The upper and lower canines produced the worst results, followed by the lower lateral incisors. The upper central incisors showed the best results, although the maximum angle of difference exceeded 20 degrees (with the median around 8 degrees). Root morphology imaging prediction is not a primary function of this software and this study confirmed its limitation as a sole tool in routine clinical applications. At present these predictions cannot be considered accurate or reliable unless correlated clinically with a radiographic image

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; p0.05) 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 socioeconomic 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

In vivo aging-induced surface roughness alterations of Invisalign® and 3D-printed aligners

Objective: To assess the surface roughness of in-house 3D-printed orthodontic aligners compared to Invisalign® appliances, both retrieved as well as in the 'as-received' control status. Design: An in vitro study following intra-oral material aging. Setting and participants: Twelve clinically used Invisalign® appliances and the same number of 3D-printed aligners were obtained from a respective number of patients, without involvement of attachments. A similar number of 'as-received' aligners of each material were used as control (CON) groups. Method: Four groups of materials were examined: A = Invisalign® CON; B = Invisalign® used; C = 3D-printed CON; and D = 3D-printed used. Optical profilometry was employed to examine the following surface roughness parameters: amplitude parameters Sa, Sq and Sz and functional parameters Sc and Sv. Descriptive statistics and quantile regression modeling were conducted, and the level of statistical significance was set at α = 0.05. Results: Intra-oral exposure of 3D-printed aligners was significantly associated with increase in all tested parameters (P < 0.001 at all occasions). Significant differences were detected in the retrieved 3D-printed aligners compared to Invisalign® retrieved, with the exception of Sz. The respective effect sizes (median differences) were as follows: Sa: 169 nm, 95% confidence interval [CI] = 89-248, P < 0.001; Sq: 315 nm, 95% CI = 152-477, P < 0.001; Sc: 233 nm3/nm2, 95% CI = 131-335, P < 0.001; and Sv: 43 nm3/nm2, 95% CI = 17-68, P = 0.002. Conclusion: Within the limitations of this report, we concluded that surface roughness differences existed between 3D-printed aligners and Invisalign® in the retrieved status, as well as between the control and retrieved 3D-printed groups. Keywords: 3D-printed; Invisalign®; aligners; optical profilometry; roughness; surface characterisatio

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 fi ve 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 defl ection 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 signifi cant (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

Thermogenic capacity of human white-fat: the actual picture

Presented at the 9th Greek Conference of Biochemistry and Physiology of Exercise, Thessaloniki, Greece, 18–20 October 2019Cold exposure and exercise may increase thermogenic capacity of white adipose tissue (WAT), which could subsequently enhance energy expenditure and body weight loss. We aimed to identify possible alterations in uncoupling protein 1 (UCP1)—the main biomarker of thermogenic activation—in human WAT due to both cold exposure and exercise, as well as the link between environmental temperature and thermogenic capacity of human WAT. MATERIAL &amp; METHOD: We conducted four human experimental studies and two systematic reviews and meta-analyses—PROSPERO registration CRD42019120116, CRD42019120213. RESULTS: UCP1 mRNA was higher in winter than in summer [t(30) = 2.232, p = 0.03] in human WAT and our meta-analysis showed a main effect of cold exposure on human UCP1 mRNA [standard mean difference (Std-md) = 1.81, confidence interval (CI) = 0.50–3.13, p = 0.007]. However, UCP1 mRNA/protein expressions displayed no associations with %fat mass or BMI (p &gt; 0.05, Cohen’s f2 &lt; 0.20). Both a 2-hour cooling and a non-cooling protocol preceding the positron emission tomography/computed tomography (PET/CT) measurements revealed no association between environmental temperature and standardised uptake value (SUVmax) of human WAT, as well as no mean differences in SUVmax-WAT-activity between winter and summer. An 8-week exercise program had no effect on UCP1 of human WAT or on body composition. Our meta-analysis also revealed: (a) no effect of chronic exercise on human UCP1 mRNA, (b) a main effect of chronic exercise on UCP1 protein concentrations (Std-md = 0.59, CI = 0.03–1.16, p = 0.04) and UCP1 mRNA (Std-md = 1.76, CI = 0.48–3.04, p = 0.007) in WAT of normal diet animals, c) a main effect of chronic exercise on UCP1 mRNA (Std-md = 2.94, CI = 0.24–5.65, p = 0.03) and UCP1 protein concentrations (Std-md = 2.06, CI = 0.07–4.05, p = 0.04) of high-fat diet animals. CONCLUSIONS: Cold exposure represents a main stimulus for increased thermogenic capacity in human white adipocytes; however, this may have no impact on body weight loss. Chronic exercise may represent no major stimulus for UCP1 induced in human white adipocytes, while in animals it increases UCP1 gene independently of their diet. Therefore, evidence from animal studies regarding UCP1 gene activation in white adipocytes may not be applicable in humans. Finally, the identification of human WAT thermogenic capacity via PET/CT examination may be optimal with both a cooling and a non-cooling protocol.Published onlin