Journal of Orofacial Orthopedics-Fortschritte Der Kieferorthopadie最新文献

Purpose: Orthodontic aligners have introduced new approaches in orthodontics, but their effects on the stomatognathic system remain debated. This longitudinal study evaluated the maximum molar bite force and strength of orofacial tissues during orthodontic treatment with aligners.

Materials and methods: Twenty individuals (16 women and 4 men) participated, with an average age of 30.8 ± 10.9 years, all having natural permanent dentition except for the third molars and no temporomandibular dysfunction. All participants were indicated for treatment with aligners and monitored over four timepoints: pretreatment, 1 month, 3 months, and 6 months after the start of treatment. The variables measured included molar bite force (right and left) using a digital dynamometer and strength of orofacial tissues (lips, tongue, and buccinator muscles) using the Iowa Oral Performance Instrument. Statistical analysis was performed using repeated measures (analysis of variance, ANOVA) and Tukey's post hoc test (P < 0.05).

Results: The maximum molar bite force significantly decreased after the start of treatment, with a trend of continuous reduction over 6 months (p = 0.04), although there were no significant differences between the timepoints and no significant changes in the left maximum molar bite force. The pressure exerted by the tongue and lips increased after the first month of aligner use, stabilizing afterwards, while buccinator muscle pressure progressively increased, showing significantly higher values compared to the pretreatment timepoint (right: 1 month, P = 0.002; 3 months, P = 0.0003; 6 months, P < 0.0001; left: 1 month, P = 0.007; 3 months, P = 0.0001; 6 months, P < 0.0002).

Conclusions: Orthodontic aligners significantly alter the function of the stomatognathic system, reducing bite force and increasing buccinator muscle pressure.

Purpose: In advanced stages of spinal muscular atrophy (SMA), established motor scores are unable to distinguish between the different degrees of remaining motor function. Bulbar muscles are affected at a later stage. The aim of the present study was to test whether oral function tests are able to better discriminate motor function than established scores and to replicate known associations between disease-related altered craniofacial anatomy and oral dysfunction in SMA.

Methods: A total of 43 adult individuals with SMA (mean age 39.7 ± 12; 25 men, 18 women) were included in this prospective, cross-sectional study. Oral function was measured using a piezoelectric sensor system and an Iowa Oral Performance Instrument (IOPI) device. Data from oral function tests and established motor scores were analyzed with regard to a possible floor or ceiling effect. It was tested to what extent SMA patients with different malocclusions presented with variable scores.

Results: Patients differed in ambulatory and treatment status (15 ambulatory vs. 28 nonambulatory; 35 treated vs. 8 nontreated) and orthodontic findings (22 with a class II molar relationship and increased overjet, 35 with posterior crossbite). In contrast to the oral function tests, some of the established motor scores showed a clear floor effect. Statistically significant associations were identified between reduced oral function values and an enlarged overjet, a class II molar relationship, and a posterior crossbite. This should be taken into account in neuromuscular evaluations.

Conclusion: In severely affected patients, oral function tests appear to be superior to established motor scores and fill a diagnostic gap in research and clinical practice.

Purpose: Regarding the therapy for positional plagiocephaly, a distinction is made between physiotherapeutic-osteopathic treatment and treatment using individual head orthoses. This retrospective study aimed to compare the outcome of these treatment modalities for correcting positional plagiocephaly in infants.

Methods: From an initial pool of 148 patients, two groups were matched based on age, sex, and Argenta classification. Therapy was either helmet therapy in combination with physiotherapeutic-osteopathic therapy (experimental group/95 patients) or physical therapy alone (control group/28 patients). The helmet was worn 23 h per day and adjusted if necessary. A photo-optical scan was performed pretherapeutically (T0) and posttherapeutically (T1). Besides other parameters, cephalic index (CI) and 30° diagonal difference (DD) were assessed and evaluated statistically. The mean age was 5.4 ± 1.1 months in the experimental group and 5.1 ± 1.0 months in the control group. The sex ratio in the experimental group was 61 males (64.2%) to 34 females (35.8%), and in the control group, it was 19 males (67.9%) to 9 females (32.1%).

Results: After alignment of the groups, the range of correction of DD in the control group (-0.4 mm ± 2.3 mm) was lower than that in the experimental group (-4.8 mm ± 2.8 mm) which was statistically significant (p = 0.001). The control group presented an average CI reduction from T0 to T1 of 0.1% ± 2.1%, while the experimental group showed a significantly higher reduction of CI of 3.6% ± 3.6% (p < 0.001). Treatment time in the helmet therapy group averaged 2.2 ± 0.6 months, and in the control group, it averaged 1.6 ± 0.5 months (p < 0.001).

Conclusions: In the matched groups, the reduction in CI and DD was significantly greater in the experimental group compared to the control group. Treatment with an individual head orthosis for positional plagiocephaly appears to be more effective than physical treatment alone.

Background and aim: The three-dimensional effects of fixed rapid maxillary expansion (RME) on palatal morphology for the treatment of maxillary constriction have been extensively studied. Morphological changes caused by treatment with removable plate appliances have not been investigated. Therefore, the aim of this retrospective cohort study was to analyse changes and follow-up stability in palatal width, height and surface area after transverse expansion with removable plate appliances in patients of different age groups.

Patients and methods: The course of treatment of n = 90 children and adolescents, documented through dental casts, was quantified using various analyses. The patient cohort (PC) was divided into three groups according to chronological age for analysis: PG 1 < 10 years of age (n = 30, early treatment), PG 2 10 to < 13 years of age (n = 30, main treatment) and PG 3 ≥ 13 years of age (n = 30, late treatment). Data were collected before treatment (T1), after transverse expansion of the palate (T2) and after completion of or retention after orthodontic treatment (T3).

Results: The average treatment interval (T1-T2) was 16.8 months. The average observation period (T2-T3) was 20.2 months. Maxillary expansion with the plate appliances occurred evenly regardless of patient age, with the greatest effects in the posterior molar region. The expansion remained stable until T3 regardless of further measures. The therapeutically induced increases in width, height and area were not significantly different between the groups despite lower initial values in the younger patients.

Conclusions: Compared to treatment with fixed RME appliances, where the effects differ due to age-related sutural changes, the morphological changes with plate appliances are comparable in patients of different chronological age. Early, main and late treatment were equally effective. This may be because the changes after treatment with plate appliances occur mainly through dentoalveolar effects, while effects on the sutures play, if any, only a minor role.

Purpose: This retrospective observational study aimed to evaluate the stability of dentoskeletal changes in skeletal class II division 1 with removable and fixed functional orthopedic appliances followed by fixed orthodontic appliances over a follow-up period of 3 years.

Methods: We included lateral cephalograms of 42 individuals who had undergone orthodontic treatment with functional jaw orthopedic appliances followed by fixed orthodontic appliances and 7 individuals who did not receive any treatment. Measurements were obtained at the start of treatment (T0) and at the end of treatment (T1) and at 3 years follow-up (T3). Participants were divided into three equal groups based on the used appliance: cast-splint Herbst (CSH), twin-block (TWB), and twin-force bite corrector (TFBC). Cephalometric assessments were performed using NemoCeph software (Nemotec, Madrid, Spain).

Results: The total follow-up period of all individuals included in the study was 39.12 ± 7.64 months after the end of the fixed orthodontic treatment. The groups differed significantly in changes in the cephalometric parameters Co-Gn, Co-Go, Co‑A, Wits appraisal, overbite, overjet, and lower lip‑E line parameters during the follow-up period. The parameters Co-Gn, Co-Go, and Co‑A in the control group increased significantly more than in the treatment groups. While the increase in overjet and overbite was significantly higher in the treatment groups compared to the control group, the regression in the lower lip‑E line was observed to decrease (except for the TFBC group).

Conclusion: Orthodontic treatment performed by applying fixed appliances after the first phase of functional jaw orthopedics can be considered stable for a 3-year follow-up period. Soft tissue changes were more common than those in the area of the skeletal structures. The observed skeletal effect of the TFBC appliance was less than that of the other two treatment devices.

Purpose: This study aimed to compare cone beam computed tomography (CBCT) and microcomputed tomography (μCT) data to evaluate the micromorphological structure of healing bone in defects created on rabbit mandibles at different stages.

Methods: Residual rabbit mandibular alveolar bone tissues from another animal study involving 18 rabbits were utilized. In the prior study, 10 × 4 mm bone cavities were created, left to heal naturally, and the animals were sacrificed after 21, 45, and 90 days. In this study, CBCT and μCT imaging were performed on the excised defect regions. The micromorphometry parameters including bone-volume fraction (BV/TV), bone-surface density (BS/TV), fractal dimension, connectivity density (Conn. Dn.), trabecular thickness (Tb.Th), and trabecular separation (Tb.Sp) were examined by ImageJ (US National Institutes of Health, Bethesda, MD, USA). Paired two-sample t‑tests, Wilcoxon test, and Bland-Altman plots were performed.

Result: Differences in the parameters Conn. Dn., fractal dimension, Tb.Th, and Tb.Sp were observed between CBCT and μCT on day 21. By day 45, no significant differences were noted in BV/TV, BS/TS, Tb.Th, and Tb.Sp. On day 90, all measured parameters showed no statistically significant differences between CBCT and μCT. Bland-Altman analysis showed an agreement for most parameters (BV/TV, BS/TV, fractal dimension, Tb.Th, and Tb.Sp) after 21, 45, and 90 days, with minimal biases emerging over time, while a more notable divergence in Conn. Dn. was observed.

Conclusion: CBCT can be used for micromorphological analyses on days 45 and 90 of bone healing as there were no differences between CBCT and μCT during these periods.

Purpose: To compare maxillary expansion achieved through the use of a rapid palatal expander (RPE) or clear aligner systems (incorporating variable buccal and palatal attachments) during mixed dentition.

Methods: The study employed the ANSYS SpaceClaim (SpaceClaim Corporation, Concord, MA, USA) software for reverse engineering and computer-aided design (CAD) tasks, utilized the ANSYS workbench for model adaptation and mesh generation, and applied the LS-DYNA solver for the resolution of the finite element model. The posterior cap splint RPE, clear aligners with buccal attachments on teeth 55, 65, 16, and 26 (CAB), and clear aligners with palatal attachments on teeth 16 and 26 (CAP) were used in the study. The appliances were modeled based on two distinct scenarios: (1) an expansion of 0.2 mm per activation of the RPE splint or per aligner; (2) a total expansion of 8 mm. The results were evaluated using finite element analysis.

Results: In the first scenario (0.2 mm activation), maximum stresses on the first molars for the RPE, CAB, and CAP models were 47.649, 26.653, and 14.040 MPa, respectively. In the second (8 mm total activation) scenario, they were 1854.022, 665.629, and 559.368 MPa. Across all models, stress levels ranked in descending order at the Z point, PNS, ANS, and A point, with RPE showing the highest overall stress values.

Conclusion: The RPE induced greater stress (indicated by red zones) on the palatal region, particularly on the palatal and buccal surfaces of the buccal segments and on the gingival area of the incisors, compared to the other two appliances. Only the RPE group showed high stress distribution in the region of the midpalatal suture. Stress on the teeth was more pronounced following the RPE compared to aligners.

Introduction: The aim of this in vitro study was to determine the difference between aligner attachments constructed from four different composite resins in terms of adhesive flash amount, removal time, and shear bond strength.

Materials and methods: In all, 80 extracted human premolars were divided into four groups (N = 20) based on the type of composites used for the fabrication of aligner attachments (Group 1: GC Aligner Connect and Group 2: GC Ortho Connect [both from GC Dental Products, Tokyo, Japan]; Group 3: Z350 XT flowable and Group 4: Filtek Z350 XT Universal [both from 3M Unitek, Monrovia, CA, USA]). After bonding, the attachments were scanned with the iTero Element® (Align® Technology, San Jose, CA, USA). The amount of adhesive flash in the overflowing areas was analyzed by comparing the bonded attachments before and after removing the adhesive flash via the software 3D Geomagic Control (3DS Systems, Rock Hill, SC, USA). A color map was used to reveal the percentage of overflowing resin. Flash adhesive removal time per tooth and shear bond strength of the attachments were also analyzed. The significance level was set at p < 0.05.

Results: The median values for the overflowing flash adhesive (surface deviation values) were 0.26, 0.29, 0.35, and 0.26 mm for Groups 1, 2, 3, and 4, respectively, with a significant difference between the groups (3 > 1, 2, 4; p < 0.001, effect size (η²) = 0.215). The percentage of red color deviation in overflowing areas was mostly observed in Group 3 (58.8%), while the green color was mostly noted in Group 4 (25%; p < 0.05). The time for removal of the adhesive flash was significantly higher in Group 1 than in Groups 2, 3, and 4 (p < 0.001, η² = 0.340). The mean bond strength of Group 4 (19.27 ± 6.37 MPa) was higher than those of Groups 1 (11.42 ± 2.54 MPa) and 2 (14.43 ± 4.61 MPa; p < 0.001 and p = 0.015, η² = 0.261).

Conclusion: Z350 XT flowable composite showed a higher overflow value and percentage of color deviation than the attachments made from the other resins. The universal restorative resin Filtek Z350 XT Universal was found to be advantageous in terms of both causing less flash adhesive and demonstrating higher bond strength to the tooth.

Purpose: Studies from the 1970s and 1980s, but also recent investigations on social media suggest that wearing a fixed orthodontic appliance can be a cause of bullying and social exclusion. With the greater uptake of orthodontic treatment in recent decades, it can be assumed that fixed braces are increasingly perceived as normal or even socially desirable. This study investigated how wearing visible fixed braces affects adolescents' social position in their peer networks using cross-sectional survey data.

Methods: A total of 3002 students in the seventh grade (ages 12/13) at 39 secondary schools were asked about their social relationships in school. These directed network data were used to compare different indegrees (friendship, popularity and victimisation) of students with and without fixed braces. Statistical analyses were performed using ordinary least squares multiple regression models with school cohort fixed effects.

Results: In all, 19% of the surveyed students indicated that they wear visible fixed braces. Girls with fixed braces were slightly more likely to be nominated for friendship and popularity and slightly less likely to be nominated for victimisation than girls without fixed braces (p < 0.05). These associations also remained stable when controlling for socioeconomic differences. Among boys, all observed associations were statistically insignificant.

Conclusion: We found no evidence that wearing fixed braces in adolescence is socially sanctioned by peers. Rather, female students with fixed braces even tend to hold a slightly more favourable position in their peer networks than girls without braces do. These analyses exemplify how network-analytic approaches can be successfully applied in interdisciplinary research at the intersection of sociology, epidemiology and medicine.

Purpose: The aim of this investigation was to evaluate the accuracy of various skeletal and dental cephalometric parameters as produced by different commercial providers that make use of artificial intelligence (AI)-assisted automated cephalometric analysis and to compare their quality to a gold standard established by orthodontic experts.

Methods: Twelve experienced orthodontic examiners pinpointed 15 radiographic landmarks on a total of 50 cephalometric X‑rays. The landmarks were used to generate 9 parameters for orthodontic treatment planning. The "humans' gold standard" was defined by calculating the median value of all 12 human assessments for each parameter, which in turn served as reference values for comparisons with results given by four different commercial providers of automated cephalometric analyses (DentaliQ.ortho [CellmatiQ GmbH, Hamburg, Germany], WebCeph [AssembleCircle Corp, Seongnam-si, Korea], AudaxCeph [Audax d.o.o., Ljubljana, Slovenia], CephX [Orca Dental AI, Herzliya, Israel]). Repeated measures analysis of variances (ANOVAs) were calculated and Bland-Altman plots were generated for comparisons.

Results: The results of the repeated measures ANOVAs indicated significant differences between the commercial providers' predictions and the humans' gold standard for all nine investigated parameters. However, the pairwise comparisons also demonstrate that there were major differences among the four commercial providers. While there were no significant mean differences between the values of DentaliQ.ortho and the humans' gold standard, the predictions of AudaxCeph showed significant deviations in seven out of nine parameters. Also, the Bland-Altman plots demonstrate that a reduced precision of AI predictions must be expected especially for values attributed to the inclination of the incisors.

Conclusion: Fully automated cephalometric analyses are promising in terms of timesaving and avoidance of individual human errors. At present, however, they should only be used under supervision of experienced clinicians.