Journal of Orofacial Orthopedics-Fortschritte Der Kieferorthopadie最新文献

Purpose: The aim of this study was to show a possible correlation between the mean wear time of Hawley retainers and long-term mandibular arch stability as assessed via wear time analysis with microsensors.

Methods: This longitudinal retrospective study comprised 47 subjects (mean age 16.30 ± 1.06 years) having been treated with a nonextraction protocol and presenting moderate crowding at pretreatment. For retention, all patients were instructed to use a mandibular Hawley retainer for 12 months, and wear time was documented every 3 months during a posttreatment period of 6 months using TheraMon software. These individuals were divided into two groups. Those who adhered to a wear time equal to or more than 12 h/day (group 1A; N = 17) and those who complied for less than 12 h/day (group 2A; N = 30) were compared with respect to changes of the mandibular arch during the first 6 months of retention. Furthermore, a subgroup of 28 patients who completed a 12-month follow-up period were again divided into two groups: the individuals in group 1B (N = 12) adhered to a wear time equal to or more than 8 h/day, while those in group 2B (N = 16) complied for less than 8 h/day. Little's Irregularity Index, intercanine and intermolar widths, arch length, overjet, and overbite were measured on mandibular models taken at pretreatment (T0) and posttreatment (T1), as well as 6 months (T2) and 12 months (T3) after debonding. Pearson correlation test, independent samples t‑test, and Mann-Whitney U test were used for statistical evaluation.

Results: From T1 to T2, group 1A and group 2A showed a significant relapse in intermolar width with a difference in the median value of 0.38 mm (p = 0.019). At the complete 12-month follow-up, the increase in Little's irregularity score was significantly greater in group 2B (2.54 ± 1.29 mm) than in group 1B (1.32 ± 1.03 mm; p = 0.012). The established wear time measurements showed significant negative correlations with the Little's irregularity score and overjet changes between T1 and T3 (p < 0.05).

Conclusions: The results emphasized that the use of a retainer should not fall below a level of at least 8 h/day.

Objectives: This study aimed to assess the efficacy of a mobile phone application (app) to improve oral hygiene of patients undergoing fixed orthodontic treatment.

Materials and methods: This randomized controlled clinical trial was conducted with a total of 60 patients undergoing fixed orthodontic treatment in two groups: intervention and control (n = 30 each). A previously designed mobile app (Labkhand) was used by patients in the intervention group. Orthodontic plaque index (OPI) and modified gingival index (MGI) were recorded in the two groups at baseline (first session or T0), and after 1 (T1) and 3 (T2) months. The number of debonded/broken brackets was also recorded, and pain score of the patients was assessed at nine time points. Data were analyzed using the χ² test, paired t‑test, and repeated measures analysis of variance (ANOVA; α = 0.05).

Results: The two groups demonstrated no significant difference in OPI and MGI at T0 (P > 0.05). OPI and MGI at T1 and T2 were significantly lower in the intervention group than in the control group (P < 0.05). The number of patients with broken brackets in the intervention group was significantly lower than that in the control group (P = 0.017). The two groups reported no significant difference in pain score (P > 0.05).

Conclusion: The Labkhand mobile app successfully improved oral hygiene indices of patients undergoing fixed orthodontic treatment, and decreased the frequency of broken brackets after 1 and 3 months of use.

Aim: Hormones play a crucial role in growth development; however, the impact of testosterone suppression (TS) on craniofacial growth during puberty remains inconclusive. This study aimed to evaluate the impact of TS during puberty on cephalometric measurements and histological characteristics of facial growth centers.

Materials and methods: Thirty-six heterogenic Wistar male rats were randomly allocated into experimental orchiectomy (ORX) and control (sham) groups. At an age of 23 days (prepubertal stage), orchiectomy and placebo surgery were performed. Cephalometric measurements were performed via lateral cephalograms during and after puberty. The animals were euthanized at an age of 45 days (pubertal stage) and 73 days (postpubertal stage). Histological slices of the growth centers (condyle, premaxilla, and median palatine suture) were stained with hematoxylin and eosin, and sirius red. Student's t or Mann-Whitney U tests were used to compare linear and angular cephalometric measurements across groups (α error = 5%).

Results: Linear and angular measurements were statistically different in ORX animals (cranial bones, maxilla, and mandible) at 45 days and 73 days. Condylar histology showed a decrease in prechondroblast differentiation and a delay of mineralization in ORX animals. Vascularization of the medium palatine suture was lower in the ORX group at 45 days. Type I and III collagen fiber synthesis was lower in the ORX groups. In the premaxillary suture, collagen fibers were better organized in the sham groups.

Conclusions: Our results suggest that testosterone suppression affects craniofacial growth during puberty.

Objective: Due to increasing numbers of adult patients presenting to orthodontic practices, an increase in incidental findings on diagnostic X‑rays, which are the cornerstone of orthodontic diagnostics, is expected. This raises the clinically relevant question of whether an age effect exists regarding prevalence, localisation and severity of incidental findings on orthodontic diagnostic X‑rays.

Materials and methods: The clinical, primarily retrospective study examined pathological incidental findings from 600 orthopantomograms (OPT) and lateral cephalogram (LC) images in two groups of orthodontic patients (group I: 150 children/adolescents, age 11.89 ± 2.47 years; group II: 150 adults, age 27.03 ± 10.42 years). Prevalence, localisation and severity of the findings were recorded based on a classification sheet. The assessment was done by three experienced examiners following a systematic approach along the nine locations: mandible, maxilla, dentition, paranasal sinuses, temporomandibular joint, cranial base, orbit, cervical spine, soft tissues.

Results: In all, 1458 incidental findings were detected, with 66% of the findings having occurred away from the dentition. There was a significant age effect (p < 0.001) with respect to the prevalence of incidental findings (group II-adults 1026 findings-OPT: 566/LC 460 vs. group I-children/adolescents 432 findings-OPT: 221/LC 211). Regarding localisation, incidental findings in adults commonly occurred in the dentition, paranasal sinuses and mandibular regions. Furthermore, analysis of the LC images revealed significantly more incidental findings in the area of the cranial base and cervical spine in adults (p < 0.001, p = 0.003). Categorisation according to the severity of the incidental findings showed that 33% of the incidental findings needed further diagnostic investigation and possibly treatment by other specialities.

Conclusion: Diagnostic assessment using orthodontic diagnostic X‑rays results in a high prevalence of incidental findings away from the dentition. Particularly in adults, a large number of incidental findings outside the dental/alveolar region may be expected on orthodontic diagnostic X‑rays. Thus, a structured approach during diagnostic assessment is required to minimise the extent to which incidental findings of clinical relevance are overlooked.

Purpose: Masticatory muscles are physically affected by several skeletal features. The muscle performance depends on muscle size, intrinsic strength, fiber direction, moment arm, and neuromuscular control. To date, for the masticatory apparatus, only a two-dimensional cephalometric method for assessing the mechanical advantage, which is a measure for the ratio of the output force to the input force in a system, is available. This study determined the reliability and errors of a three-dimensional (3D) mechanical advantage calculation for the masticatory system.

Methods: Using cone-beam computed tomography images from teenage patients undergoing orthodontic treatments, 36 craniofacial landmarks were identified, and the moment arms for seven muscles and their load moment arms (biomechanical variables) were determined. The 3D mechanical advantage for each muscle was calculated. This procedure was repeated by three examiners. Reliability was verified using the intraclass correlation coefficient (ICC) and the errors by calculating the absolute differences, variance estimator and coefficient of variation (CV).

Results: Landmark coordinates demonstrated excellent intra- and interexaminer reliability (ICC 0.998-1.000; p < 0.0001). Intraexaminer data showed errors < 1.5 mm. Unsatisfactory interexaminer errors ranged from 1.51-5.83 mm. All biomechanical variables presented excellent intraexaminer reliability (ICC 0.919-1.000, p < 0.0001; CV < 7%). Interexaminer results were almost excellent, but with lower values (ICC 0.750-1.000, p < 0.0001; CV < 10%). However, the muscle moment arm and 3D mechanical advantage of the lateral pterygoid muscles had ICCs < 0.500 (p < 0.05) and CV < 30%. Intra- and interexaminer errors were ≤ 0.01 and ≤ 0.05, respectively.

Conclusions: Both landmarks and biomechanical variables showed high reliability and acceptable errors. The proposed method is viable for the 3D mechanical advantage measure.

Objectives: This study aimed to design and implement a mobile phone application (app) aiming to enhance the cooperation and oral hygiene of orthodontic patients.

Methods: An orthodontic app named "Labkhand" was designed by a team of orthodontists and programmers according to the needs and scheduled interventions for patients. The aim of this app was to obviate the orthodontic needs of patients by providing educational content in the form of texts and videos, oral hygiene reminders, appointment reminders, and nutrition reminders. It also enabled instant messaging and chatting between patients and dental personnel. In this study, 61 patients were monitored during their orthodontic treatment procedure. All patients were evaluated using a questionnaire with 7 questions before and after a 6-month treatment period. A total of 31 patients were instructed to use the app, while the other 30 patients received treatment without the app. The collected data were analyzed using paired t‑test and analysis of covariance (ANCOVA) test.

Results: While the control group's questionnaire score remained almost the same (P > 0.05), the mean questionnaire score of patients in the intervention group significantly increased after using the app compared to the baseline scores acquired before using the app (P < 0.001). The greatest improvement was noted in topics related to "reminding of appointments", "general information about orthodontic treatment", and "oral hygiene maintenance and instructions". "Quality of services" and "patient-orthodontist communication" showed the least improvement in patient satisfaction.

Conclusions: The Labkhand orthodontic app has multiple functions and can obviate the needs of orthodontic patients easily and at a low cost.

Objectives: Reduced occlusal function is a main characteristic of orthognathic patients. The present study aimed to investigate the extent of therapy-induced functional improvements in occlusal function using a digital diagnostic method.

Methods: This prospective clinical study included 41 orthognathic patients (24 women and 17 men, median age 27.26 ± 8.2 years) and 10 control patients (5 women and 5 men, median age 29.8 ± 13.5 years) with neutral skeletal and dental configurations. The patients were divided into classes I, II and III based on their cephalometry. Digital occlusal registrations in habitual occlusion in an upright sitting position were taken before (T1) and after (T2) therapy using the T‑Scan Novus (Tekscan, South Boston, MA, USA) application.

Results: Class II and III patients showed a significantly less efficient occlusal pattern than the untreated controls regarding total antagonism (p < 0.001), time of occlusion (p = 0.004), occlusal asymmetry (p = 0.001), anterior antagonism (p < 0.001) and posterior antagonism (p < 0.001). After therapy, the occlusal pattern increased in both therapy groups, where class III patients became indistinguishable from the controls, and class II patients differed only in posterior antagonism (p = 0.035).

Conclusions: The digital occlusal registration method proved to be a useful diagnostic tool and provided new insights into therapeutic effects in orthognathic patients. By precisely adjusting the occlusal function, masticatory performance improved significantly.

Clinical relevance: Severe malocclusion leads to a significantly lower masticatory performance for patients, which can be improved by orthognathic therapy and captured by digital occlusal registration.