Digital workflows have become integral in orthodontic diagnosis and therapy, reducing risk factors and chair time with one-visit protocols. This study assessed the transfer accuracy of fully digital planned insertion guides for orthodontic mini-implants (OMIs) compared with freehanded insertion. Cone-beam computed tomography (CBCT) datasets and intraoral surface scans of 32 cadaver maxillae were used to place 64 miniscrews in the anterior palate. Three groups were formed, two using printed insertion guides (A and B) and one with freehand insertion (C). Group A used commercially available customized surgical templates and Group B in-house planned and fabricated insertion guides. Postoperative CBCT datasets were superimposed with the planning model, and accuracy measurements were performed using orthodontic software. Statistical differences were found for transverse angular deviations (4.81° in A vs. 12.66° in B and 5.02° in C, p = 0.003) and sagittal angular deviations (2.26° in A vs. 2.20° in B and 5.34° in C, p = 0.007). However, accurate insertion depth was not achieved in either guide group; Group A insertion was too shallow (−0.17 mm), whereas Group B insertion was deeper (+0.65 mm) than planned. Outsourcing the planning and fabrication of computer-aided design and computer-aided manufacturing insertion guides may be beneficial for certain indications; particularly, in this study, commercial templates demonstrated superior accuracy than our in-house–fabricated insertion guides.

Objectives: The objective of the present study was to analyze the relapse rate and the magnitude of relapse after mandibular distraction osteogenesis (MDO) using cephalometric measurements. Materials and methods: The sample comprised 63 patients (49 women, 14 men) with moderate to severe mandibular retrognathia, mean age of 22.6 years, who underwent MDO between 2010 and 2021. Data were collected from CBCTs recorded preoperatively (T0), after the active distraction phase (T1), and 12 months after the distraction phase (T2). Two-dimensional cephalometry analyses were performed. Results: The mean cephalometric advancement was at T1 for mandibular body length (MBL) 10.30 mm, for mandibular unit length (MUL) 8.00 mm, and for SN-Pog 4.84°. At T2, MUL decreased by 0.26 mm (p = 0.14), and MBL by 0.22 mm (p = 0.39). A positive correlation between the magnitude of distraction and the magnitude of relapse was identified (MBL p = 0.045; MUL p = 0.002). Conclusions: MDO is a reliable method of advancing the mandible in retrognathic adult patients.

ZusammenfassungDer kieferorthopädische Lückenschluss ist eine wichtige Alternative zur prothetischen Restauration mit Implantaten. Diese Zahnbewegung im Oberkiefer kann durch eine stark nach kaudal ausladende Kieferhöhle mit steil ansteigendem vertikalem Kieferhöhlenboden und weit in den Sinus reichende Zahnwurzeln erschwert werden. Die vorgestellten Fallberichte 2 und 3 zeigen eine Methode zur Erleichterung eines translatorischen Lückenschlusses durch die Kieferhöhle mithilfe eines interdisziplinären chirurgischen Ansatzes (Sinuslift mit Augmentation) bei sehr tief reichendem Sinus maxillaris.Die radiologische und klinische Bewertung dieser beiden kieferorthopädischen Fälle zeigte eine erfolgreiche translatorische kieferorthopädische Zahnbewegung durch eine stark vergrößerte Kieferhöhle, die durch Knochenaugmentation unter Verwendung eines synthetischen Knochenersatzmaterials unterstützt wurde. Es gab keine signifikanten Anzeichen einer Wurzelresorption.

Orthodontic gap closure is an important alternative to prosthetic restorations with implants. This tooth movement in the upper jaw can be complicated by a strongly caudaly projecting maxillary sinus with a steeply rising vertical maxillary sinus floor and tooth roots reaching far into the sinus. Case reports 2 and 3 demonstrate a new method to facilitate bodily gap closure through the maxillary sinus with the help of an interdisciplinary surgical approach (sinus lift and bone augmentation). Radiologic and clinical evaluation of these two orthodontic cases showed successfully translational orthodontic tooth movement through an enlarged sinus supported by bone augmentation using a synthetic augmentation material. There were no significant signs of root resorption.

There are many different philosophies, concerning orthodontic treatment of cleft lip and palate. There is no international consensus regarding cleft management today. However, the basic considerations in treating these very common congenital malformations are very similar, as they automatically result from the deficiencies of soft tissues, bones and teeth. A not inconsiderable aspect is the handling of deviations from the natural symmetry, which primarily exist in unilateral clefts, which generally occur more frequently than the bilateral malformations.

Herein, we demonstrated the synthesis of multifunctional alkyne building blocks from commercially available acrylate monomers exploiting the carbon and oxa Michael addition reaction. These compounds were obtained in decent yields and show similar or even higher photoreactivity than the initial acrylates. Importantly, selected thiol-yne formulations can be processed by stereolithography and significantly outperform the corresponding acrylate in terms of modulus and toughness. The high compatibility of such cured materials with osteosarcoma cells makes these photopolymers interesting for hard tissue engineering.

Wann weist ein Patient ein erhöhtes Rezidiv-Risiko auf und ist dauerhafte festsitzende Retention vertretbar?

ZusammenfassungBezüglich der kieferorthopädischen Behandlung von Lippen-, Kiefer- und Gaumenspalten gibt es viele verschiedenen Philosophien. Derzeit existiert kein international einheitliches Konzept. Die grundlegenden Überlegungen, die Behandlung dieser sehr häufigen angeborenen Fehlbildungen betreffend, sind jedoch sehr ähnlich, da sie sich automatisch aus den Defiziten von Weichteilen, Knochen und Zähnen ergeben. Ein nicht unwesentlicher Aspekt ist dabei der Umgang mit Abweichungen von der natürlichen Symmetrie, die in erster Linie bei einseitigen Spalten zu finden sind, die generell häufiger vorkommen als die doppelseitigen Fehlbildungen.

This study deals with the investigation of photocurable thiol-yne resins covering several important aspects for the production of medical devices by UV-based manufacturing processes. In this context, the performance of different low-toxic photoinitiators (PIs) and stabilizers are evaluated in thiol-yne formulations based on di(but-1-yn-4-yl) carbonate and various multifunctional thiol monomers. Photodifferential scanning calorimetry measurements reveal that the conversion of all resin formulations is mostly independent on the type and concentration of the applied photoinitiator; however, significant differences in their curing speed are observed. It turns out that the migration of an alkyne derivatized photoinitiator is significantly reduced while providing almost similar photoactivity as its nonfunctionalized reference. Moreover, it is found that lauryl gallate and butylated hydroxytoluene lead to significant stabilization without affecting the overall photoreactivity. Notably, the thermomechanical properties of the investigated photopolymers are only slightly affected by water absorption. Using ester free thiols, water absorption can be reduced and hydrolytically stable polymers are realized. These results highlight the versatility of the present thiol-yne system for the production of medical materials by photopolymerization.

•A nonsurgical successful therapy of an epulis (reactive hyperplastic lesion of the gingiva) is presented.•Report of a photodynamic therapy following conservative periodontal pre-treatment.•This form of treatment of an epulis by photodynamic therapy has the potential being a nonsurgical alternative to conventional surgical excision.

The decision for an extraction treatment in Class I borderline cases is sometimes difficult and is influenced by many factors.In this review article different aspects of extraction treatment are presented. The most frequent reasons will be discussed, as well as the occurrence of root resorptions, success of treatment, dental arch changes, influence of extraction on the duration of orthodontic treatment, condylar position and effects on profile and soft tissue - changes. Moreover the relation between extraction treatment and third molar impaction rate, stability and the tendency of incisor relapse is explained.

Die Entscheidung zur Extraktionstherapie bei Klasse-I-Grenzfällen ist oft sehr schwierig zu treffen bzw. wird von verschiedenen Faktoren beeinflusst. In dieser Arbeit werden mittels Literaturrecherche unterschiedliche Aspekte zur Extraktionstherapie dargestellt. Dabei werden die häufigsten Extraktionsgründe und Extraktionsmuster, das Auftreten von Wurzelresorptionen, Behandlungserfolge, Zahnbogenveränderungen sowie der Einfluss einer Extraktionstherapie auf die Dauer der Behandlung, der Kondylenposition, mögliche Profil- und Weichteilveränderungen diskutiert. Auch der Zusammenhang zwischen Extraktionstherapie und der Impaktierung von Weisheitszähnen, der Stabilität und des Auftretens eines Frontzahnrezidivs wird erläutert.

The goal of this study was to assess the extent to which median mandibular distraction via a cemented and screw-retained full-coverage splint appliance employing a hinged expansion screw causes inclination changes in the lower first molars and widens the dental arch.

In cases of bilateral clefts of lip and palate there is often a vertical and transversal deficit of the cleft segments. Ideally these problems can be solved orthodontically. In severe cases there is a need of surgical support. Distraction osteogenesis allows the correction of transversal, horizontal, and vertical deficits. A case of a 13-year-old girl with a bilateral cleft of lip and palate is presented. The patient had a severe deficit of the distal cleft segments concerning the vertical and transversal dimension. Osteotomy of the segments was performed and a vertical distraction followed by a transpalatal distraction procedure was used to correct the discrepancies.

Restoration, such as a bridge or an implant, which unfortunately is also dependent on bone

OBJECTIVES:To evaluate changes in the palatal vault after rapid maxillary expansion (RME) with bonded splint appliances. SETTING AND SAMPLE POPULATION:The sample comprised 24 children (12 boys and 12 girls) with mixed dentition (mean age 8.3 years; range 6.4-10.4 years). MATERIALS AND METHODS:Following expansion, the splint appliance was used as a retainer for 6 months and then removed. Study casts were taken before RME (T0) and when the appliance was removed (T1). Then, 3D laser scans were taken to build complete 3D jaw models. Frontal cross sections were constructed at 53-63, 55-65 and 16-26, exported as coordinates, and finite element calculated to quantify their area, width and height. Maxillary length was also determined. RESULTS:Paired t-tests indicated statistically significant increases in the average palatal width (T1-T0=6.53-6.79 mm) and cross-sectional area (T1-T0=20.39-21.39 mm2) after RME (p<0.001). However, small but statistically significant reductions were observed in palatal height (T1-T0=-0.49 mm, only at 55-65; p<0.001) and length (T1-T0=-0.54 mm; p<0.01). Linear regression analysis showed statistically significant (p<0.001) direct correlations between the widths and respective cross-sectional areas. Age did not influence any measurement. The reliability of the measurements was examined with an intraclass correlation coefficient (ICC). We found an ICC>0.99 (p<0.001) for all tested parameters. CONCLUSIONS:Rapid maxillary expansion distinctly increased mean palatal widths and cross-sectional areas. However, palatal height (55-65) and maxillary length decreased to a small extent.