Journal of Orofacial Orthopedics-Fortschritte Der Kieferorthopadie最新文献

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.

Background: Supernumerary teeth are an alteration of dental developmental and result in the formation of teeth above the usual number. Epidemiologic studies suggested that patients with dentofacial anomalies and their family members may present an increased risk of developing cancer, including female breast cancer and gynecologic cancers. These observations indicate that genetic alterations that result in dental anomalies may be related to cancer development. Thus, the aim of the present study was to evaluate the association between supernumerary teeth and a family history of female breast cancer and gynecologic cancers.

Methods: The diagnosis of supernumerary teeth was based on clinical and radiographic examinations. For data collection, a questionnaire asking for information regarding ethnicity, age, gender, and self-reported family history of cancer up to the second generation was used. Statistical analysis was performed using the Χ² test and Fisher's exact test with an established α of 5%.

Results: A total of 344 patients were included; 47 of them had one or more non-syndromic supernumerary teeth (not associated with any syndrome or cleft lip and palate) and 297 were control patients. Age, ethnicity, and gender distribution were not statistically different between the group with supernumerary teeth and the control group (p > 0.05). The supernumerary teeth were most commonly observed in the incisors area. Breast cancer (n = 17) was the most commonly self-reported type of cancer, followed by uterine cervical (n = 10), endometrial (n = 2), and ovarian (n = 1) cancers. Endometrial cancer was significantly associated with the diagnosis of supernumerary teeth (p = 0.017).

Conclusion: This study suggests that patients with supernumerary teeth possess a higher risk of having family members with endometrial cancer.

Purpose: This systematic review aimed to assess the effects of orthopedic functional appliances for anterior open bite (AOB) in primary or mixed dentition children.

Methods: A search for randomized controlled trials (RCT) was conducted in November 2020 in electronic databases with no data or language restrictions. Primary outcomes were skeletal cephalometric variables and adverse events. We used the Cochrane risk-of-bias tool to assess methodological quality and the GRADE approach to assess the certainty of the evidence.

Results: We identified five RCTs (220 participants). Very low certainty evidence showed an improvement in overbite (mean difference [MD] 3.60; 95% confidence interval [CI] 2.63-4.57) and in the angulation of the upper incisors to the palatal plane (MD 3.70; 95% CI 0.85-6.55) with Frankel's functional regulator, compared to no treatment. There was no difference in the measured cephalometric variables when comparing removable palatal crib to fixed palatal crib, bonded spurs, and chin cup. When comparing removable versus magnetic bite blocks, a beneficial effect was observed in overbite, overjet, skeletal anteroposterior angular measurements, and skeletal vertical linear measures in the magnetic group. No adverse events were reported.

Conclusion: There was insufficient evidence to infer the effects of these treatments for AOB, and high-quality RCTs are needed to increase the estimated effects.

Prospero register: CRD42020175634, prospectively registered (05 July 2020).

Purpose: The present study aims to compare the M‑mode ultrasound findings of different skeletal malocclusions and to evaluate whether sonographic parameters can be used for the diagnosis of malocclusions.

Methods: Tongue movements of 36 adolescents aged between 10.37 and 17.29 years (mean 14.25 ± 1.78 years) were assessed using simultaneous two-dimensional real-time B‑mode and M‑mode sonography. The swallowing patterns of the subjects were visualized recording the motion of the tongue surface in the ultrasound images utilizing a fixed scan line through the middle of the tongue. M‑mode scans of tongue motion during empty deglutition were recorded. The parameters range, duration, and speed were computed for the entirety of the swallowing process using M‑mode examination. Findings were evaluated and statistically analyzed.

Results: No clear intraindividual repeatability in the M‑mode imaging of the subjects' swallowing process could be observed. Considering the setup used in the study, it was not always possible to distinguish individual swallowing stages in the M‑mode images with regard to the chosen reference points. The average duration, range of motion, and speed of swallowing were found to be 2.43 s, 24.06 mm, and 10.34 mm/s, respectively. The findings showed both intra- and intersubject variability during empty swallowing.

Conclusion: With the help of the metrics that could be calculated based on the M‑mode images, it was not possible to differentiate the swallowing acts of different skeletal malocclusion types. It remains unclear whether M‑mode imaging can accurately visualize the swallowing pattern. Therefore, further progress in technology and multidisciplinary work is needed in order to establish diagnostic references regarding swallowing.

Aim: This study evaluated artificial bone models against a human bone substitute to assess the primary stability of orthodontic mini-implants (OMIs) at varying implant sites with different morphologies and qualities.

Materials and methods: A total of 1200 OMI placements of four types were inserted into four artificial bone models of different density (D1, D2, D3, D4) and into a human bone substitute (HB). The implants varied in diameter (2.0 and 2.3 mm) and length (9 and 11 mm). Each specimen had four implant sites: no defect, one-wall defect, three-wall defect, and circular defect. The implant stability quotient (ISQ) values were measured using resonance frequency analysis (RFA) and insertion placement torque values (IPT) were assessed for primary stability. Correlation analysis was performed to evaluate the different models.

Results: The highest IPT value was registered for the 2.0 mm × 11 mm implant inserted into D1 with no defect (37.53 ± 3.02 Ncm). The lowest ISQ value was measured for the 2.3 mm × 9 mm OMI inserted into D3 with a circular defect (12.33 ± 5.88) and the highest for the 2.3 mm × 9 mm implant inserted into HB with no defect (63.23 ± 2.57). A strong correlation (r = 0.64) for IPT values and a very strong correlation (r = 0.8) for ISQ values was found between D2 and HB.

Conclusion: Bone defects and bone quality affected the primary stability of implants in terms of ISQ and IPT values. Results for bone model D2 correlated very well with the HB substitution material.

Short root defects are prone to cause various periodontal diseases and lead to tooth loss in some serious cases. Studies about the mechanisms governing the development of the root are needed for a better understanding of the pathogenesis of short root defects. The protein family with sequence similarity 20 group C (FAM20C) is a Golgi casein kinase that has been well studied in the development of tooth crown formation. However, whether FAM20C plays a role in the development of tooth root is still unknown. Thus, we generated Sox2-Cre;Fam20c^fl/fl (cKO) mice, in which Fam20c was ablated in both the dental epithelium and dental mesenchyme, and found that the cKO mice showed severe short root defects mainly by inhibiting the development of dental mesenchyme in the root region. In this investigation, we found morphological changes and differentiation defects, with reduced expression of dentin sialophosphoprotein (DSPP) in odontoblasts of the root region in cKO mice. Furthermore, the proliferation rate of apical papillary cells was reduced in the root of cKO mice. In addition, the levels of bone morphogenetic protein 4 (BMP4) and phospho-Smad1/5/8, and that of Osterix and Krüppel-like factor 4 (KLF4), two downstream target molecules of the BMP signaling pathway, were significantly reduced in the root of cKO mice. These results indicate that FAM20C plays an essential role in the development of the root by regulating the BMP signaling pathway.

Objectives: New opportunities have arisen to manufacture three-dimensional computer-aided design/computer-aided manufacturing (3D CAD/CAM) retainers from titanium blocks by digital cutting technology. These novel technologies need to fulfill requirements regarding digital planning and position accuracy. The aim of the present study was to investigate the digital construction, the CAD/CAM production and the intraoral positioning accuracy of custom-manufactured novel 3D CAD/CAM titanium retainers.

Materials and methods: A total of 37 prime4me® RETAIN3R (Dentaurum, Ispringen, Germany) retainers were inserted to stabilize the upper anterior front teeth. Following insertion, an intraoral scan was used to record the position. The intraoral position was compared to the virtual setup using 3D superimposition software. Measurement points were evaluated in all three dimensions (horizontal, sagittal and vertical planes). Data were analyzed using Kruskal-Wallis test followed by Dunn's multiple comparison test.

Results: A total of 185 measurements were performed. The horizontal plane and the sagittal plane demonstrated a high level of positioning accuracy between the planned and the intraoral position. Statistically significant deviations between the preceding virtual setup and the intraoral situation were observed in the vertical dimension. Within the retainer, the intraoral positioning accuracy decreased for the measurement points in the direction of the distal retainer segment.

Conclusion: Based on the results, the present study shows a high level of congruence between the 3D virtually planning and the final intraoral position of the fabricated novel 3D CAD/CAM titanium retainers.

Purpose: The aim of this retrospective multicenter study is to evaluate the influence of surgical manipulation of the upper occlusal plane (UOP) and orthodontic decompensation on the outcome of class III orthognathic surgery.

Methods: Incisor inclinations, occlusal plane inclination as well as skeletal and soft tissue changes were assessed in lateral cephalograms of 85 class III patients who had previously undergone orthognathic surgery. Fourteen linear and eight angular measurements were performed on each radiograph at the beginning of treatment (T0), before surgery (T1) and at the end of treatment (T2) using imaging software. After measurement of variables, Mann-Whitney U‑test, repeated-measures analysis of variance (ANOVA) with Bonferroni multiple comparison test, and Spearman's correlation analysis were performed.

Results: A statistically significant improvement was observed in both sagittal skeletal and soft tissue measurements (p < 0.05). Surgical change in UOP was significantly correlated with changes in overbite, upper lip strain and soft tissue B‑point change in the sagittal direction (p < 0.05). Overjet change was significantly correlated with changes in the soft tissue and all sagittal skeletal parameters except for SNA. Changes in the incisor inclinations was significantly correlated with changes in the sagittal skeletal parameters and lower facial height. Significant differences were also observed between the groups with induced clockwise or counterclockwise rotation of the mandible in terms of IMPA (long axis of LI to mandibular plane), overbite, upper lip strain and position of soft tissue B‑point (p < 0.05).

Conclusion: Sufficient dental decompensation is crucial for controlling the sagittal as well as the vertical relationship during surgery. Counterclockwise rotation provides an increase in sagittal projection of the mandibular body at the soft tissue B‑point.

Purpose: This study aimed to evaluate the effects of lower premolar extraction on posttreatment stability one year following fixed orthodontic treatment with passive self-ligating brackets (Damon system, Ormco, Orange, CA, USA).

Methods: All patients were treated with fixed orthodontic appliances using passive self-ligating brackets (Damon). For retention, removable Hawley retainers were used. Two groups of patients were included in the study. Each group consisted of 23 patients: group Ex consisted of 10 male and 13 female patients (13.4 ± 1.6 years old) with extraction of lower first premolars and group NonEx consisted of 11 male and 12 female patients (13.4 ± 3.9 years old) without dental extractions. The patients' dental models and photographs were assessed at T0 (pretreatment), T1 (the end of active orthodontic treatment: 3.3 ± 1.0 years in the Ex and 2.3 ± 0.8 years in the NonEx group) and at T2 (1 year posttreatment). All lower casts were scanned and the following dental parameters were recorded and compared between the two groups: intercanine width (ICW), anterior arch width (AAW), intermolar width (IMW), Little's irregularity index (LII) and gingival recessions.

Results: An increase in ICW (group Ex: 1.20 ± 2.51 mm and group NonEx: 0.84 ± 1.48 mm) by the end of active treatment (T1; P < 0.05), as well as a relapse regarding the ICW (group Ex: -0.1 ± 0.47 mm and group NonEx: -67% ± 0.38 mm) one year post-treatment (T2) were recorded in the samples. Relapse in the non-extraction group was statistically and clinically significant, whereas ICW values remained relatively stable in the extraction group during the posttreatment period (T1-T2). The irregularity index decreased during treatment (group Ex: -8.79 ± 6.36 mm and group NonEx: -5.24 ± 2.99 mm) and relapsed in both groups (group Ex: 0.57 ± 90 mm and group NonEx: 0.27 ± 0.53). The rate of relapse in LII was correlated to the relapse rate of ICW. A reduction of IMW was recorded in the Ex group (-1.89 ± 1.82 mm) during active treatment (P < 0.05), which remained stable 1 year posttreatment. AAW increased in both groups (group Ex: 2.77 ± 1.77 mm and group NonEx: 1.77 ± 2.04 mm) throughout active treatment and remained stable at T2.

Conclusion: Intergroup comparison revealed that ICW remained stable 1 year posttreatment in the Ex group, whereas high relapse of ICW was recorded in the NonEx group. Furthermore, risk of a relapse of LII appears to be higher in cases with a relapse of the ICW.