Turkish Journal of Orthodontics最新文献

Objective: To compare the effects of low-frequency vibration (LFV), photobiomodulation (PBM), and their combination (HOT) on the rate of mandibular incisor alignment during clear aligner therapy.

Methods: This retrospective study included 89 patients treated with a single clear aligner system for mild-to-moderate mandibular anterior crowding. Patients were assigned to four groups: control (n=19), LFV (n=26), PBM (n=21), and HOT (n=23). LFV [30 Hz, 0.25 N (≈25 g)] and PBM (850 nm, 16×5 mm LEDs, ≈9.5 J/cm²) devices were used daily for 20 minutes in relevant groups. The primary outcome was the change in Little's Irregularity Index at baseline (T0), 28 days (T1), 48 days (T2), and 62 days (T3). Statistical analyses included one-way ANOVA, repeated measures ANOVA, and Pearson's correlation.

Results: The HOT group showed significantly greater crowding reduction compared to all other groups (p<0.05). LFV and PBM alone were not significantly different from the control. Within-group analysis revealed significant reductions in all groups over time, with the HOT group showing consistent improvements at each interval. Correlation analyses revealed no significant associations between device usage or aligner wear time and crowding reduction.

Conclusion: Combining LFV and PBM during clear aligner therapy produced greater short-term acceleration of mandibular incisor alignment than either modality alone. Further randomized controlled trials are warranted to confirm long-term efficacy and safety.

Objective: The aim of our study was to evaluate root resorption on maxillary teeth neighboring osteotomy sites in response to segmental LeFort I osteotomy over time.

Methods: Eighteen subjects, aged 18 to 65 years with pre-surgery (T0), post-surgery (T1), and long-term follow-up (T2) CBCT records were included. Sixteen control subjects, aged 17.67 to 62.33 years, with pre-treatment (T0), progress (T1), and long-term progress orthodontic (T2) CBCT records were also used. Maxillary central incisor, canine, and first molar roots were segmented. The volume, surface area, and root length changes were analyzed using repeated measures ANOVA and mean differences across follow-up periods. Significance was set at p<0.05.

Results: The surgical group had an overall increase in the amount of root resorption in all time comparisons and variables with significance (p<0.05) in length, volume, and surface area. When comparing mean differences between the control and surgical groups, no significant differences were observed except for a few variables.

Conclusion: LeFort I segmental osteotomy in conjunction with orthodontic treatment, induces root resorption. However, except for a few variables, the differences compared to orthodontic treatment alone are not statistically significant. Moreover, these findings are clinically insignificant.

Objective: Temporary anchorage devices (TADs) enhance the efficiency of fixed functional appliances (FFAs) by providing stable anchorage, improving skeletal and dental corrections, optimizing vertical control, and enhancing treatment outcomes for Class II and III malocclusions. TADs also help prevent the proclination of the lower incisors and the distalization of the molars, which are commonly observed with FFAs lacking skeletal anchorage. This study aims to analyze the displacement and stress distribution patterns generated in craniofacial structures and dentition using conjoined implants and intermaxillary elastics for growth modification in growing Class II patients.

Methods: Finite element analysis was conducted using cone-beam computed tomography data from an 11-year-old patient with Class II Division 1 malocclusion. Mini-implants and miniplates were designed and assembled in SolidWorks, meshed using HyperMesh, and analyzed in Abaqus 6.14 to evaluate stress and displacement patterns under a 450 g orthopedic force applied via Class II elastics.

Results: In the mandible, the highest principal and von Mises stresses were observed on the posterior surface of the ramus, whereas in the maxilla, stress concentrations were noted lateral to the nasal aperture. Additional stress concentrations were identified in the region posterior to the glenoid fossa. The mandible was displaced anteroinferiorly as a whole, while the maxilla exhibited posterosuperior displacement. Dental movements included maxillary expansion with intrusion of the anterior teeth, and anterior displacement of the mandibular dentition, primarily resulting from bodily movement.

Conclusion: The use of Class II elastics in combination with Temporary Anchorage Devices (TADs) produces greater stress and displacement in skeletal structures compared to the dentition. As a result, this treatment approach is more likely to produce substantial skeletal changes than dental alterations.

Objective: Orthodontic camouflage effectively addresses mild to moderate skeletal Class III malocclusion by repositioning the mandible and anterior teeth. However, recent findings suggest potential temporomandibular joint (TMJ) impact of the intermaxillary elastics frequently used in this treatment. This study aims to comprehensively assess changes in the TMJ and dentoskeletal relationship following Class III camouflage treatment, using a combination of CBCT and MRI.

Methods: This clinical trial enrolled skeletal Class III malocclusion patients meeting eligibility criteria. Non-extraction camouflage treatment was administered, employing the straight wire technique with conventional Class III intermaxillary elastics. CBCT and MRI were conducted at baseline (T0) and after achieving normal occlusion (T1). Condylar position in three dimensions and dentoskeletal relationship were assessed from CBCT images using Dolphin^® imaging software, while TMJ disc position and length were measured from MR images using MicroDicom software. Statistical analyses were performed with IBM^® SPSS^® software.

Results: The dataset comprised nine subjects, with a mean age of 24.3±7.0 years. CBCT analyses indicated significant changes in dentoskeletal relationship, especially those of the mandible (increased ANB 2.32±0.51°, increased SN-MP 2.61±1.05°, decreased profile angle 5.40±1.07°), but nonsignificant changes in condylar position post-treatment (0.11±0.15 mm). Similarly, MRI measurements demonstrated non-significant changes in both position (0.91±1.61°) and length (0.07±0.37 mm) of the articular disc post-treatment.

Conclusion: Class III camouflage treatment using conventional intermaxillary elastics significantly improves the dentoskeletal relationship without significant adverse effects on the condyle and articular disc of the TMJ.

Objective: This study aimed to explore variations in enamel thickness to provide guidelines for optimal interproximal enamel reduction in an untreated population using cone-beam computed tomography (CBCT).

Methods: CBCT scans of 100 orthodontic patients (51 Caucasian, 49 patients of Somalian descent; aged (12-18) were analyzed retrospectively. Enamel thickness was measured at the mesial and distal contact points of teeth from the second molar to the central incisor in both the maxillary and mandibular arches. Linear mixed models were employed to assess the effects of ethnicity, gender, anterior-posterior region, and mesial-distal proximal surfaces on enamel thickness. Fixed effects were estimated using the Kenward-Roger method, and a random intercept with an unstructured covariance matrix was included to account for within-subject variability. Ethnicity-specific residual variances were also modeled. Statistical significance was set at p<0.05.

Results: Enamel thickness varied significantly between Caucasians and Somalians in both the maxilla and mandible (p<0.001), with greater thickness observed in Caucasians. Gender-related differences were minimal; however, in the maxilla, distal surfaces of posterior teeth had greater enamel thickness in females compared to males (p=0.0478). Enamel thickness was consistently greater on distal surfaces of posterior teeth (p<0.001), while no significant differences were observed between mesial and distal surfaces in anterior teeth (p>0.05).

Conclusion: Posterior teeth, particularly distal proximal surfaces of premolars and molars hold a great potential for enamel reduction, offering clinicians the most optimal site in orthodontic interventions.

Diabetes mellitus is a chronic condition characterized by insufficient insulin production or utilization. Affecting approximately 8.5% of adults globally, diabetes is categorized primarily into Type 1, Type 2, and gestational diabetes. Diabetes markedly impacts bone health, particularly affecting the growth and development of the mandible. Key alterations include impaired bone metabolism leading to diminished bone density and strength. Additionally, diabetes impairs bone healing processes, often exacerbated by deficiencies in vitamin D, thus increasing fracture risks. Understanding the interplay between diabetes and mandibular growth is essential for effective dental treatment planning and patient management. Importantly, the condition also alters essential growth factors and local blood supply to the mandibular region, compromising overall growth. Impaired bone healing and formation also affects orthodontic treatment in diabetic patients. Future research should prioritize longitudinal studies examining diabetes's long-term impact on mandibular development, exploring genetic predispositions and biomechanical properties. Understanding these mechanisms will facilitate more effective clinical strategies to mitigate the adverse effects of diabetes on bone health and optimize patient outcomes.

The aim of this systematic review was to evaluate the clinical outcomes of skeletal anchorage, compared to conventional anchorage, in the treatment of skeletal Class III malocclusion in growing patients. A systematic review was conducted following PRISMA guidelines. A specific search strategy was developed for PubMed, Web of Science, Embase, and Cochrane searching for randomized controlled trials and non-randomized clinical trials. Eleven interventions were assessed, three employing conventional anchorage (group A) and eight skeletal anchorage (group B). Nine pre-treatment (T0) and post-treatment (T1) mean cephalometric outcomes were statistically polled (SNA, SNB, ANB, Wits, Overjet, Overbite, SNMP, IMPA, U1PP). In total, 196 studies were identified, 17 studies were included in the qualitative and quantitative analysis. In the skeletal anchorage group, a greater increase in both ANB (+2.511°) and Wits (+4.691 mm) were observed and the increase in SNMP resulted well-controlled (+0.758°). The conventional anchorage group showed higher dentoalveolar side effects: increase in U1PP (+5.624°), decrease in IMPA (-0.866°) and increase in overjet (+5.255 mm). Treatments exploiting skeletal anchorage determined a better correction of skeletal Class III, thanks to a combination of greater advancement of the maxilla and more enhanced retrusion of the mandible. In all treatment protocols exploiting dental anchorage, the increase in the inclination of the central incisor resulted significantly greater. Further longitudinal studies are required to evaluate the long-term effects of skeletal anchorage in growing patients.

Objective: The aim of this study is to evaluate the effects of maxillary advancement (MxA) and bimaxillary osteotomy (MdS-MxA) on upper pharyngeal airway volume (PAV), apnea-hypopnea index (AHI), hyoid bone (HB) position, and head posture (HP) in young and healthy individuals with skeletal Class III malocclusion.

Methods: This prospective clinical study included three groups: MxA, MdS-MxA, and Class I control group, with 12 subjects each. In the surgical groups, lateral cephalometric radiographs, cone-beam computed tomography images, and AHI measurements were obtained preoperatively and approximately six months postoperatively. Only pre-treatment records were collected for the control group. Depending on data distribution, parametric (Paired Samples t-test and ANOVA) or non-parametric (Wilcoxon Signed-Rank and Kruskal-Wallis) tests were used for intra- and inter-group statistical comparisons, with a significance level set at p<0.05.

Results: The maxillary forward movement for the MxA group was 5.34 mm. It was 5.32 mm in the MdS-MxA group, and the mandibular setback was 4.71 mm. Nearly six months after surgery, significant differences were observed among the groups in the sagittal positions of the jaws, the vertical position of the mandible, the vertical position of the hyoid bone, and PAV sections. No significant differences were found in HP, minimum cross-sectional area or AHI.

Conclusion: PAV increase was observed in both surgical groups. MdS-MxA did not have an effect on obstructive sleep apnea. Postoperative HB displacement was minimal, with a slight inferior shift observed in the MdS-MxA group.

Objective: This study aims to evaluate the effect of low-level laser therapy (LLLT) on leveling mandibular anterior crowding and associated pain levels.

Methods: This double-blinded, parallel, randomized clinical trial included 30 participants who were randomly assigned to the laser group or the control group, with Little's irregularity index of 4-8 mm in the mandibular canine-canine region. Nickel-titanium archwires measuring 0.012 inches were tied with elastomeric ligatures and changed every 14 days throughout the leveling process. The leveling duration was recorded in days, from the bonding application to the end of leveling. Irradiation was performed at an 810-nm wavelength using a gallium-aluminum-arsenide diode laser device with a power output of 100 mW and an energy density of 8 J/cm². Laser applications were performed after archwire ligation (day 0), on days 3, 7, and 14 and every 14 days until leveling was completed. The leveling duration was calculated, and pain levels were evaluated using a visual analogue scale (VAS) after archwire ligation (hour 0), at hours 2 and 6 and on days 1, 3, 7, 14, and 21.

Results: The leveling duration showed no significant differences between the laser and control groups (p=0.170). Group comparison results of the VAS scores at hour 6 (p=0.001) and day 1 (p=0.006) exhibited significantly reduced pain levels in the laser group compared with the control group.

Conclusion: Although LLLT is not effective in reducing the leveling duration, it significantly reduces pain levels at hour 6 and on the 1^st day.

Objective: To compare skeletal ages determined using three different regression methods from measurements made on cervical vertebrae from lateral cephalometric radiographs (LCRs) with the skeletal age determined from hand-wrist radiographs (HWRs).

Methods: LCRs and HWRs of 794 individuals (329 boys, 465 girls) aged 7-18 years were examined. The hand-wrist skeletal age of the participants was determined using the Greulich-Pyle (GP) atlas. Forty-four linear and nine angular morphometric measurements in the C2-C5 vertebrae were made in LCRs. Vertebral skeletal age (VSA) was determined in both sexes using Ridge, the least absolute shrinkage and selection operator (LASSO), and ElasticNet regression methods. The study results were evaluated using R2 (explainability power). Bland-Altman analysis was performed to determine the consistency of chronologic age (CA), GP age, and VSAs.

Results: LASSO regression showed the highest explainability power for VSA, with boys at 0.783 and girls at 0.741. In both sexes, the vertebral depth of concavities had high beta coefficients, and the posterior height of C3 vertebrae (TVup-TVlp) had the highest beta coefficient in boys in LASSO regression. The width of the limits of agreement in both CA and VSA graphs of GP age was wider in boys than in girls. The width of the limits of agreement of CA-VSAs was wider in girls than in boys.

Conclusion: Although high R2 values were obtained, VSA showed no superiority over CA in the assessment of skeletal age, and no significant clinical advantage was observed. For the Turkish population, using GP age may be more accurate for determining skeletal age in orthodontic treatment planning.