Comparison of soft tissue injury by Piezosurgery® and rotating instruments based on the example of the inferior alveolar nerve of the pig

In der Mund-, Kiefer-, Gesichtschirurgie wurden in den letzten Jahren zunehmend alternative Methoden zur Knochenbearbeitung eingesetzt. Die Ultraschallosteotomie, bei welcher der Knochen durch Applikation hochfrequente elektromechanische Schwingungen geschnitten wird, ist ein solches Verfahren. Ziel dieser Studie war es, das Ultraschallosteotomieinstrument Piezosurgery (Mectron Medical Technology, Italien) mit der konventionellen Kugelfräse im Hinblick auf Weichgewebsschädigung des Nervus alveolaris inferior, nach Osteotomie eines Knochenfensters im Schweinekiefer, zu vergleichen. Bezüglich der Weichgewebsschädigung war in beiden Gruppen kein Unterschied ersichtlich.In recent years alternative methods have been used in maxillofacial surgery to deal with bony tissue. Ultrasonic osteotomy, where high frequency electromechanical oscillation is applied to cut the bone, is one of these methods. The aim of this study was a comparison of Piezosurgery (Mectron Medical Technology, Italy), an ultrasonic osteotomy instrument, and conventional rotary instruments with regard to soft tissue damage to the inferior alveolar nerve after osteotomic fenestration of a pigs mandible. Both groups showed no difference regarding soft tissue injury

Relationship between back posture and early orthodontic treatment in children

Background The purpose of this study was to analyze the relationship between body posture and sagittal dental overjet in children before and after early orthodontic treatment with removable functional orthodontic appliances. Methods Angle Class II patients (mean age 8.2 +/- 1.2 years; 29 males and 25 females) with a distinctly enlarged overjet (> 9 mm) were retrospectively examined regarding body posture parameters before and after early orthodontic treatment. In addition, changes in overjet were investigated with the aid of plaster models. Forms of transverse dysgnathism (crossbite, lateral malocclusions) and open bite cases were excluded. Body posture parameters kyphosis, lordosis, surface rotation, pelvic tilt, pelvic torsion and trunk imbalance were analyzed by means of rasterstereographical photogrammetry to determine, if the orthodontic overjet correction is associated with specific changes in posture patterns. Results In nearly all patients an overjet correction and an improvement regarding all body posture and back parameters could be noted after early orthodontic treatment. Overjet reduction (- 3.9 mm +/- 2.1 mm) and pelvic torsion (- 1.28 degrees +/- 0,44 degrees) were significantly (p 0.05). Conclusion Overjet reduction during early orthodontic treatment may be associated with a detectable effect on pelvic torsion

Relationship between back posture and early orthodontic treatment in children

Background!#!The purpose of this study was to analyze the relationship between body posture and sagittal dental overjet in children before and after early orthodontic treatment with removable functional orthodontic appliances.!##!Methods!#!Angle Class II patients (mean age 8.2 ± 1.2 years; 29 males and 25 females) with a distinctly enlarged overjet (> 9 mm) were retrospectively examined regarding body posture parameters before and after early orthodontic treatment. In addition, changes in overjet were investigated with the aid of plaster models. Forms of transverse dysgnathism (crossbite, lateral malocclusions) and open bite cases were excluded. Body posture parameters kyphosis, lordosis, surface rotation, pelvic tilt, pelvic torsion and trunk imbalance were analyzed by means of rasterstereographical photogrammetry to determine, if the orthodontic overjet correction is associated with specific changes in posture patterns.!##!Results!#!In nearly all patients an overjet correction and an improvement regarding all body posture and back parameters could be noted after early orthodontic treatment. Overjet reduction (- 3.9 mm ± 2.1 mm) and pelvic torsion (- 1.28° ± 0,44°) were significantly (p < 0.05) and moderately correlated (R = 0.338) with no significant associations found for the other posture and back parameters (p > 0.05).!##!Conclusion!#!Overjet reduction during early orthodontic treatment may be associated with a detectable effect on pelvic torsion

Conformity, reliability and validity of digital dental models created by clinical intraoral scanning and extraoral plaster model digitization workflows

Background: In dentistry, digitization of dental arches with intraoral scanners could one day replace impressions and plaster model digitization processes, if accuracy is clinically sufficient. This study aimed to assess the reliability, validity and conformity of an intraoral scanning procedure (Lythos (c), Ormco) and of two extraoral digitization workflows via alginate impression and plaster model scanning with the D810 (c) (3shape) or the Atos II Triple Scan (c) (GOM) under clinical conditions. Methods: In 20 subjects three consecutive intraoral scans, three alginate and one reference polyether impression were taken of both the upper and lower dental arch, respectively. The digital models created from the corresponding plaster models and the intraoral scans were superimposed with the polyether reference standard by both a global and a local best-fit algorithm. Reliability, validity and conformity of the three digital workflows were assessed via intraclass (ICC) and Lin's concordance correlation coefficients (CCC) as well as analyses according to Bland-Altman. Results: The digital models created from the intraoral scanning procedure were less in agreement with the polyether reference (validity) than those from the extraoral procedures with reduced conformity and reliability. Local numerical deviations from the reference standard were approximately twice as high compared to the extraoral procedures, which showed high conformity and were equivalent and clinically acceptable in terms of reliability and validity. Conclusions: Although the intraoral scanning method with Lythos (c) seems to have drawbacks in terms of reliability, validity and conformity to the indirect alginate methods, all procedures proved to be clinically equivalent for diagnostic purposes

Three-dimensional quantitative assessment of palatal bone height for insertion of orthodontic implants - a retrospective CBCT study

Abstract Background Orthodontic implants have found widespread use as means of maximum skeletal anchorage in fixed orthodontic treatment, their optimal insertion location in the hard palate, however, is still controversial. The aim of this study was therefore to assess mean bone height across the hard palate and possible age- and sex related differences to identify the most favourable location according to maximum bone height, optimizing primary stability and survival of inserted orthodontic implants. Methods In this retrospective cross-sectional study, maxillary pretreatment CBCT scans of 180 healthy orthodontic patients (95♀, 85♂, age 8–40 years) were analysed with regard to vertical palatal bone height in the midpalatal area at 88 validated points distanced 2 mm from each other forming a grid of 0–14 mm posterior to the incisive foramen and 10 mm lateral of the midpalatal suture. Differences in bone height regarding sex and topographical location were assessed by three-way ANOVA. Results In general, the midpalatal suture as well as the anterior-lateral palatal region showed distinctly higher mean palatal bone height with its maximum 4 mm posterior of the incisive foramen, whereas bone height was limited at the posterior region of the midpalatal suture. Women generally had significantly decreased palatal bone height compared to men at all measurement points. Higher age was associated with a decrease of bone height in the anterior and posterior lateral palatal region and the median palatal raphe with significant age differences. Conclusions The midpalatal suture as well as the anterior lateral palate seem to be most suitable for the insertion of orthodontic implants. Palatal bone height, however, was found to be sex- and age-specific, thus sex- and age-related differences should be taken into account, particularly regarding implant length. The ideal insertion site in the palate with sufficient bone height for orthodontic implants is 0-8 mm (men) or 0-6 mm (women) posterior to the incisive foramen and 10 mm lateral to the midpalatal suture. Trial registraion This study has been registered and approved by the Ethics Committee of the University of Witten/Herdecke, Germany (12/2016)

Fluoride release from two types of fluoride-containing orthodontic adhesives: Conventional versus resin-modified glass ionomer cements-An in vitro study.

IntroductionDevelopment of white spot lesions (WSLs) during orthodontic treatment is a common risk factor. Fixation of the orthodontic appliances with glass ionomer cements could reduce the prevalence of WSL's due to their fluoride release capacities. The purpose of this study was to evaluate differences of fluoride release properties from resin-modified and conventional glass ionomer cements (GICs).MethodsThe resin-modified GICs Fuji ORTHO LC (GC Orthodontics), Meron Plus QM (VOCO), as well as the conventional GICs Fuji ORTHO (GC Orthodontics), Meron (VOCO) and Ketac Cem Easymix (3M ESPE) were tested in this study. The different types of GICs were applied to hydroxyapatite discs according to the manufacturer's instructions and stored in a solution of TISAB III (Total Ionic Strength Adjustment Buffer III) and fluoride-free water at 37°C. Fluoride measurements were made after 5 minutes, 2 hours, 24 hours, 14 days, 28 days, 2 months, 3 months and 6 months. One factor analysis of variance (ANOVA) was used for the overall comparison of the cumulative fluoride release (from measurement times of 5 minutes to 6 months) between the different materials with the overall level of significance set to 0.05. Tukey's post hoc test was used for post hoc pairwise comparisons in the cumulative fluoride release between the different materials.ResultsThe cumulative fluoride release (mean ± sd) in descending order was: Fuji ORTHO LC (221.7 ± 10.29 ppm), Fuji ORTHO (191.5 ± 15.03 ppm), Meron Plus QM (173.0 ± 5.89 ppm), Meron (161.3 ± 7.84 ppm) and Ketac Cem Easymix (154.6 ± 6.09 ppm) within 6 months. Analysis of variance detected a significant difference in the cumulative fluoride release between at least two of the materials (rounded p-value ConclusionFluoride ions were released cumulatively over the entire test period for all products. When comparing the two products from the same company (Fuji ORTHO LC vs. Fuji ORTHO from GC Orthodontics Europe GmbH and Meron Plus QM vs. Meron from VOCO GmbH, Mannheim, Germany), it can be said that the resin-modified GICs have a higher release than conventional GICs. The highest individual fluoride release of all GICs was at 24 hours. A general statement, whether resin-modified or conventional GICs have a higher release of fluoride cannot be made

Fluoride Ion Release Characteristics of Fluoride-Containing Varnishes—An In Vitro Study

Despite the latest advances in orthodontic treatment, white spot lesions remain a common side effect of fixed appliance therapy. An effective treatment for the prevention of white spot lesions is the use of fluoride-containing products. The aim of the present in vitro study was to check the durability of the tested products for their fluoride release into the surrounding solution. Three varnishes (Protecto CaF2 Nano one-step seal, Bifluorid 12 single dose, and Fluor Protector S) were applied to hydroxyapatite discs and kept in diluted Total Ionic Strength Adjustment Buffer III (TISAB III) solution for fluoride ion release measurement. A group of clear hydroxyapatite discs served as the control group. The carrier discs (N = 40) underwent three thermal cycling runs for 20 days. Before the first run and after each run, the fluoride ion concentration in the solution was measured at appointed times (T) T0, T1, T2, and T3. Fluoride ion release was highest at T1 for all products (median values for Protecto CaF2 Nano one-step seal: 0.09 ppm, Bifluorid 12 single dose: 37.67 ppm, and Fluor Protector S: 3.36 ppm) except for the control group, showing its peak at T0 (0.04 ppm). There was a significant difference between the tested fluoride varnishes at all measurement times. Bifluorid 12 achieved significantly higher fluoride release values than the other products (p < 0.05 at all measurement times). A solitary product application of only once or twice per year, as stated by the manufacturers, cannot be supported

Effects of different surgical techniques and displacement distances on the soft tissue profile via orthodontic-orthognathic treatment of class II and class III malocclusions

Background!#!Orthognathic surgery can be carried out using isolated mandibular or maxillary movement and bimaxillary procedures. In cases of moderate skeletal malocclusion, camouflage treatment by premolar extraction is another treatment option. All these surgical procedures can have a different impact on the soft tissue profile.!##!Methods!#!The changes in the soft tissue profile of 187 patients (Class II: 53, Class III: 134) were investigated. The treatment approaches were differentiated as follows: Class II: mandible advancement (MnA), bimaxillary surgery (MxS/MnA), upper extraction (UpEX), or Class III: maxillary advancement (MxA), mandible setback (MnS), bimaxillary surgery (MxA/MnS), and lower extraction (LowEX) as well as the extent of skeletal deviation (moderate Wits appraisal: - 7 mm to 7 mm, pronounced: Wits &amp;lt;- 7 mm, &amp;gt; 7 mm, respectively). This resulted in five groups for Class II treatment and seven groups for Class III treatment.!##!Results!#!In the Class II patients, a statistically significant difference (p ≤ 0.05) between UpEX and moderate MnA was found for facial profile (N'-Prn-Pog'), soft tissue profile (N'-Sn-Pog'), and mentolabial angle (Pog'-B'-Li). In the Class III patients, a statistically significant differences (p ≤ 0.05) occurred between LowEX and moderate MxA for facial profile (N'-Prn-Pog'), soft tissue profile (N'-Sn-Pog'), upper and lower lip distacne to esthetic line (Ls/Li-E-line), and lower lip length (Sto-Gn'). Only isolated significant differences (p &amp;lt; 0.05) were recognized between the moderate surgical Class II and III treatments as well between the pronounced Class III surgeries. No statistical differences were noticed between moderate and pronounced orthognathic surgery.!##!Conclusions!#!When surgery is required, the influence of orthognathic surgical techniques on the profile seems to be less significant. However, it must be carefully considered if orthognathic or camouflage treatment should be done in moderate malocclusions as a moderate mandibular advancement in Class II therapy will straighten the soft tissue profile much more by increasing the facial and soft tissue profile angle and reducing the mentolabial angle than camouflage treatment. In contrast, moderate maxillary advancement in Class III therapy led to a significantly more convex facial and soft tissue profile by decreasing distances of the lips to the E-Line as well as the lower lip length

Orofacial findings and orthodontic treatment conditions in patients with down syndrome – a retrospective investigation

Abstract Introduction The most common chromosomal anomaly is Down syndrome/Trisomy 21, which can be associated with varying degrees of intellectual disability and physical malformation. Specific orofacial characteristics regarding orthodontic treatment options and features are described on the basis of a patient collective from the Witten/Herdecke University, Germany. Methods Data of 20 patients (14 boys and 6 girls, mean age: 11.69 ± 3.94 years) who underwent orthodontic treatment between July 2011 and May 2022 were analyzed. Baseline skeletal and dental conditions were assessed, as well as the presence of hypodontia, displacements, and treatment-related root resorptions. The treatment need was evaluated based on the main findings according to the German KIG classification. In addition, treatment success was determined in relation to patient compliance. Results The patient group was characterized predominantly by a class III relationship (ΔANB: −2.07 ± 3.90°; ΔWITS: −3.91 ± 4.33 mm) and a brachyfacial cranial configuration (ΔML-NL: −4.38 ± 7.05°, ΔArGoMe: − 8.45 ± 10.06°). The transversal discrepancy of the dental arch width from maxilla to mandible was −0.91 ± 3.44 mm anteriorly and −4.4 ± 4.12 mm posteriorly. Considering the orthodontic indication groups, the most frequent initial finding and treatment indication represented hypodontia (85%), followed by frontal (75%) and unilateral lateral (35%) crossbite. In 55% of the cases, the teeth had a regular shape, but in 35% a generalized and in 15% an isolated hypoplasia. Only 25% of the patients could be treated with a fixed multiband appliance due to sufficient cooperation. In each of these patients, varying degrees of root resorptions were detected during treatment, and 45% of all treatments had to be terminated prematurely due to a lack of cooperation by patients or parents. Conclusion The extent of dental and skeletal malformations and the high rate of findings requiring treatment in patients with Down syndrome represent a significant indication for orthodontic therapy, which can be well illustrated by the KIG classification. However, this is in contrast to the eventually increased risk of root resorption, with significantly reduced patient cooperation. A compromised treatment outcome and process must be expected. Consequently, the orthodontic treatment must be simple and realistic to achieve fast and therapeutically satisfactory treatment result

Evaluation of symmetry behavior of surgically assisted rapid maxillary expansion with simulation-driven targeted bone weakening

Objectives!#!Surgically assisted rapid maxillary expansion (SARME) is a treatment modality to overcome maxillary constrictions. During the procedure of transverse expansion, unwanted asymmetries can occur. This retrospective study investigates the transverse expansion behavior of the maxilla utilizing a simulation-driven SARME with targeted bone weakening.!##!Materials and methods!#!Cone beam computer tomographies of 21 patients before (T1) and 4 months after treatment (T2) with simulation-driven SARME combined with a transpalatal distractor (TPD) and targeted bone weakening were superimposed. The movements of the left, right, and frontal segments were evaluated at the modified WALA ridge, mid root level, and at the root tip of all upper teeth. Linear and angular measurements were performed to detect dentoalveolar changes.!##!Results!#!Dentoalveolar changes were unavoidable, and buccal tipping of the premolars (6.1° ± 5.0°) was significant (p &amp;lt; 0.05). Transverse expansion in premolar region was higher (6.13 ± 4.63mm) than that in the molar region (4.20 ± 4.64mm). Expansion of left and right segments did not differ significantly (p &amp;gt; 0.05).!##!Conclusion!#!Simulation-driven SARME with targeted bone weakening is effective to achieve symmetrical expansion in the transverse plane.!##!Clinical relevance!#!Simulation-driven targeted bone weakening is a novel method for SARME to achieve symmetric expansion. Dental side effects cannot be prohibited