Journal of Orofacial Orthopedics-Fortschritte Der Kieferorthopadie最新文献

Objectives: To measure and compare the canine retraction (CR) and molar mesial migration (MMM) rates using micro-osteoperforation (MOP) and low-level laser therapy (LLLT).

Materials and methods: This randomized split-mouth study included 20 patients. Following premolar extractions and levelling, the maxillary arch was divided into the right and left halves: group A received MOPs (performed once at T0), and group B underwent LLLT using a gallium-aluminum-arsenide diode laser (810 nm, 100 mW, continuous mode), applied biweekly for 3 months around the canine region. Segmental CR was performed with NiTi coil springs (150 g) using mini-implant anchorage. Digital scans at T0 (baseline), T1 (45 days), and T2 (90 days) were analyzed using three-dimensional (3D) software. Retraction rate was calculated as distance moved per time (mm/day).

Results: The CR rate was significantly higher in the MOP group (0.03297 ± 0.0092 mm/day) than in the LLLT group (0.01865 ± 0.0070 mm/day, p = 0.000). The MOP group showed a decline from T1 (0-45 days; 0.03297 ± 0.0092 mm/day) to T2 (45-90 days; 0.02245 ± 0.0071 mm/day). MMM was higher in the LLLT group (0.00239 ± 0.0007 mm/day) than in the MOP group (0.00189 ± 0.0006 mm/day) but had a negligible impact on total space closure. The rate of retraction in the MOP group was 1.77 times faster, making it the primary contributor to space closure.

Conclusion: MOP significantly accelerated orthodontic tooth movement compared to LLLT across all time intervals with minimal MMM and few adverse effects on the molars.

Purpose: This study aimed to evaluate the performance of large language models (LLMs), specifically GPT-4o and Gemini 2 Flash, in identifying external apical root resorption (EARR) on panoramic radiographs of orthodontic patients using a standardized prompt.

Methods: This comparative observational diagnostic study included 52 cropped tooth images obtained from panoramic radiographs of healthy individuals after orthodontic treatment. From each image, the regions corresponding to the permanent maxillary and mandibular incisors were manually cropped to include the apex, surrounding alveolar bone, and crown. An expert in endodontics evaluated each cropped image for the presence and severity of EARR using the Malmgren scale. The same images were submitted to both LLMs (GPT-4o and Gemini 2 Flash) using an identical multimodal prompt (image and text instructions). The models' responses were compared to the expert ratings using Cohen's kappa (κ), accuracy, F1-score, mean absolute error (MAE), and confusion matrices. The Wilcoxon signed-rank test was used to compare the MAE between the models. Confidence intervals (95%) were calculated via bootstrapping.

Results: According to the expert evaluation, EARR was identified across all Malmgren grades: 11 teeth (21.2%) showed no resorption, 11 (21.2%) irregular apical contour, 11 (21.2%) small apical resorption, 11 (21.2%) resorption up to one-third of the root length, and 8 (15.4%) exceeding one-third resorption. GPT-4o showed fair agreement with the expert for the binary classification (κ= 0.371), whereas Gemini exhibited a negative κ (-0.152), indicating performance below chance. GPT-4o achieved 36.5% accuracy and a MAE of 1.269 in severity classification, compared to 13.5% accuracy and a MAE of 1.750 for Gemini. Both models performed poorly in detecting moderate to severe EARR. The Wilcoxon test showed no significant difference between the models (p > 0.05).

Conclusion: GPT-4o achieved numerically better results than Gemini, with lower error rates and slightly higher agreement with the expert. Nevertheless, both models showed limited accuracy and agreement, particularly in detecting moderate to severe resorption, and neither can be considered suitable for clinical application at this stage.

Purpose: The objective of the present systematic review (SR) was to compare available retainers to determine which one has the highest probability of maintaining a stable post-orthodontic outcome.

Methods: Electronic platforms were searched up to 20 January 2024 to identify randomized controlled trials (RCTs) comparing the efficacy of different retainers in stabilizing post-orthodontic tooth position (PROSPERO no. CRD42023399604). The Cochrane checklist was used for risk of bias assessment. Network meta-analyses (NMA) were conducted for the Little irregularity index (LII), intercanine width (ICW), and intermolar width (IMW) to identify metric ranking markers (highest probability of being the best [PBB], surface under the cumulative ranking curves [SUCRA], and mean ranking [MR]) for the different retention protocols.

Results: Eighteen RCTs were included in the SR, and 15 in the NMA. Seven studies were at high risk of bias, 7 at moderate, and 4 at low risk of bias. The retainers were categorized into 14 groups for analyzing LII, 13 for ICW, and 8 for IMW. The NMA on LII indicated that computer-aided design/computer-aided manufacturing (CAD/CAM) multistrand stainless steel (SS), followed by laboratory round multistrand SS and rectangular flex SS retainers had the highest PBB in maintaining a low LII. The NMA on ICW suggested that CAD/CAM multistrand SS followed by CAD/CAM NiTi and spring hard SS retainers have the highest PBB in maintaining ICW. Very limited evidence showed a low PBB for removable retainers related to LII and ICW. No difference between groups was observed for IMW.

Conclusion: There is moderate-to-low quality evidence that CAD/CAM and laboratory-bent multistrand SS followed by rectangular flex SS retainers might be the most effective retention protocol for maintaining a low LII over a short-to-mid-term follow-up, whereas CAD/CAM multistrand SS, CAD/CAM NiTi, and spring-hard wire retainers might be most effective in maintaining ICW. Intermolar width tends to decrease, but this does not seem to be influenced by the type of retention.

Purpose: This study aimed to evaluate the effect of the use of chewable probiotic tablets on interleukin-10 (IL-10) and tumor necrosis factor‑α (TNF-α) levels in gingival crevicular fluid (GCF) in patients undergoing treatment with fixed orthodontic appliances.

Methods: This prospective case-control study involved 60 patients undergoing treatment with fixed orthodontic appliances. Participants were divided into two groups. The test group was administered probiotic chewable tablets (Motiflor AS, Abfen Farma, Ankara, Turkey) once daily for 15 days, and the control group received routine orthodontic treatment without probiotics. GCF samples were collected from each participant at two time points: at the beginning of the treatment (T0) and on the 21st day (T1). Samples were obtained separately from all four canines using collection strips. The levels of IL-10 and TNF‑α in GCF were analyzed using the enzyme-linked immunosorbent assay (ELISA) method. Statistical tests were performed to assess the normality of the distribution of quantitative variables. All analyses were performed using GraphPad Prism (version 9.1.1, GraphPad Software, San Diego, CA, USA). Data normality was assessed using the Kolmogorov-Smirnov test. Friedman's test for repeated measures was employed, followed by Dunn's post hoc test.

Results: The variability that was observed for the IL-10 cytokine levels in the control group was significantly higher than that for the test group (p < 0.05). IL-10 levels in the test group increased while the TNF‑α levels decreased. T1/T0 ratio for TNF‑α was found to be lower in the test group compared to the control group (p = 0.002).

Conclusion: The results suggest that probiotic tablets may play a role in modulating IL-10 and TNF‑α levels during orthodontic tooth movement. However, the current study was limited to the first 21 days of mechanical force application to the teeth, and it is recommended to investigate the long-term effects or other factors affecting cytokine changes in future studies.

Purpose: External apical root resorption is an undesirable outcome of orthodontic treatment. Patients with already existing root resorption who require orthodontic treatment should be carefully evaluated. The objective of this study was to evaluate the effect of apical root resorption and different orthodontic forces on stress and displacement in the tooth and periodontium using a three-dimensional (3D) finite element analysis method.

Methods: Two 3D models of an upper central incisor were constructed based on tomographic images. Two models (original tooth length and an apical resorption of 3 mm) and four types of force application (intrusion, extrusion, tipping, and translation) resulted in eight variations from the two original study factors (apical resorption and orthodontic movement). The mechanical properties, mesh, boundary conditions, and loading were added to the specific finite element analysis software (Ansys, Houston, PA, USA). Orthodontic forces (0.6 N) were applied to the brackets to simulate orthodontic movements.

Results: Quantitative analysis showed that the highest von Mises tension values were found in the models subjected to translational movement, regardless of the root condition. The values obtained for the displacement of the studied structures did not differ significantly. In a qualitative analysis comparing teeth with and without apical resorption, teeth with apical resorption showed higher stress concentrations in the cortical bone and periodontal ligament.

Conclusion: Apical resorption did not significantly influence maximum displacement of the involved structures but influenced stress in the periodontal tissues. The translational movement resulted in the highest stress values in the tooth and periodontal tissues.

Purpose: To evaluate the skeletal, dentoalveolar and soft tissue changes in patients treated with the Forsus fatigue resistance device (FRD) appliance in combination with a full slot labially pretorqued mandibular archwire in class II patients and compare it with applying a conventional plain mandibular archwire.

Methods: The total sample of 31 individuals was divided into three groups: group 1 (G1) with 11 patients (Forsus appliance therapy combined with an 8° labially pretorqued full slot 0.021″ × 0.028″ stainless steel archwire in mandible), G2 with 10 patients (Forsus appliance therapy combined with a plain 0.021″ × 0.025″ stainless steel archwire in mandible), and an untreated control group (GC) with 10 patients. Lateral cephalograms before placement of the Forsus appliance and at end of class II correction with an average time of 6 ± 2 months were analyzed.

Results: The paired students t test revealed that class I molar relation, overjet and overbite correction were achieved in the G1 and G2 individuals. Both G1 individuals (IMPA: 7.18°; L1-NB: 1.64 mm, 7.73°) and G2 individuals (IMPA: 8.40°; L1-NB: 2.00 mm, 7.70°) exhibited lower incisor proclination. However, there was no statistically significant difference in the lower incisor position in the two treatment groups. N to point A and SNA values decreased in G1, while the Wits value decreased in G2. The post hoc test showed significant changes in incisor inclination, molar position, and overjet between the treated groups and the GC.

Conclusion: A Forsus appliance combined with a 0.022″ × 0.028″ labially pretorqued archwire in the mandibular arch showed favorable improvements that were similar to those with a plain 0.021″ × 0.025″ stainless steel archwire with no significant difference in terms of mandibular incisor position (i.e., proclination) and maxillary point A position. However, a Forsus appliance combined with a 0.022″ × 0.028″ labially pretorqued archwire in the mandibular arch showed better distal positioning of maxillary point A , although statistically insignificant.

Purpose: The purpose of this cross-sectional study was to use multiple regression analysis to evaluate the relationship between the mandibular curve of Spee (COS) and the maxillary compensating curve with dentoskeletal morphology in young Chinese adults with normal occlusion.

Methods: This study comprised 62 young adults (31 males, mean age: 24.1 ± 2.2 years; 31 females, mean age: 23.3 ± 3.3 years) with Angle class I normal occlusion. For every subject, intraoral scan models of the maxillary and mandibular arches and lateral cephalograms were acquired. The depth of the COS and compensating curve were assessed on the intraoral scan models. Multiple dental arch dimensional and cephalometric variables were screened by univariate analysis. Subsequently, a multiple linear regression model (forward stepwise selection) was constructed to determine which variables were significantly correlated with the two curve depths.

Results: In the mandible, the COS depth was deepest at the mesiobuccal cusp of the first molar. Overjet, mandibular arch width and mandibular-occlusal plane angle significantly correlated with the COS depth (P < 0.05), accounting for 33.1% of the variation in the mandibular COS. In the maxilla, the deepest point of the compensating curve was at the distobuccal cusp of the first molar. Mandibular arch perimeter and overbite significantly correlated with the maxillary compensating curve (P < 0.05), explaining 23.3% of the variation.

Conclusions: Overjet, overbite, mandibular-occlusal plane angle, mandibular arch width and perimeter should be considered when reconstructing occlusal curves in clinical orthodontic treatment and in prosthetic restoration.

Background: This research aimed to study whether bracket bonding using guided bonding devices (GBDs) is accurate enough for crowded dentitions in vitro.

Methods: Fifteen three-dimensionally (3D) printed resin model sets were included and divided into three groups: mild, moderate, and severe crowding. The resin models were scanned and virtually bonded with brackets. Corresponding GBDs were generated and 3D printed. Subsequently, the brackets were bonded to the resin models on a dental mannequin using the GBDs. The models with bonded brackets were scanned, and comparisons were made between the positions of the actually bonded and the planned ones to evaluate possible deviations.

Results: There was no immediate bonding failure in any group. The bonding duration tended to increase with crowding severity (P > 0.05). Almost all linear and angular deviations in all groups were below 0.5 mm and 2°, respectively, and no statistically significant difference was found among the different crowding degrees (P > 0.05). In all groups, the brackets tended to deviate lingually and had buccal crown torque. Brackets in the groups with mild and severe crowding showed a tendency for mesiobuccal rotation.

Conclusion: GBDs provide high bracket bonding accuracy for dentitions with different crowding degrees and, thus, could hopefully be applied to uncrowded and crowded dentitions alike.

Background and aim: In Germany, the reimbursement of orthodontic treatment costs within the framework of the statutory health insurance (GKV) was restricted on 01 January 2002 by the introduction of the orthodontic indication groups (KIG). The aim of this study was to evaluate the prevalence of findings requiring treatment in a specialist practice over a 20-year period. The results were then compared with data from existing older studies.

Patients and methods: The distribution of treatment-eligible KIG (KIG classifications grades 3-5) among patients with statutory health insurance in an orthodontic practice in North Rhine was determined over a 20-year period (2002-2021) after the introduction of the KIG system. This period was additionally scrutinized in four 5‑year periods according to the operating cycles of the practice. Findings were classified into the highest of 19 possible KIG treatment needs levels. Multiple classifications were not made.

Results: Orthodontic treatment was indicated in a total of 4537 (2393 female, 2144 male) patients according to current statutory health insurance guidelines. The KIG classification "D" (increased overjet) was the most frequent within the observed 20 years with 24.3%. Among 11 KIG classifications, 86.1% of the 6 most frequent and 13.9% of the 5 rarest findings were observed constantly over all periods. Of 19 possible indications, "D4" was the most frequent with 19.6%. Of 4537 patients, 20.7% had KIG grade 3, 63.6% KIG grade 4 and 15.7% KIG grade 5. The prevalence of sagittal deviations "D" and "M" was 35.0%, transverse "B" and "K" 17.9% and vertical "O" and "T" 3.7%. Tooth position anomalies "E" and "P" had a share of 24.6%.

Conclusions: The present study confirms existing findings as well as the nationwide data of the National Association of Statutory Health Insurance Dentists (KZBV) from 2020: The sagittal deviations "D" (increased overjet) and "M" (negative overjet) represented the most frequent findings with KIG D4 as the most common classification. The prevalence and age distribution of KIG grades 3-5 requiring treatment corresponded to nationwide comparative data.