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The achievement of aesthetic, functional occlusion should not mark the end of the orthodontic intervention. To prevent relapse, retention needs advance planning, and may vary in duration. This review aims to present and comment on the available means of retention. The ever-popular, passive Hawley-like removable appliances are credible in maintaining the desired occlusion. Modifications are the removable appliance Wrap Around, having the labial archwire extending to the premolars; the translucent retainer, Astics, a unique aesthetic Hawley-type device; and the reinforced removable retainer, which features a metallic grid reinforcing the acrylic base. Vacuum-formed retainers are easy to fabricate and are readily prescribed. By contrast, fixed retainers are made of orthodontic wire and composite resin bonded on the lingual or palatal surfaces of the anterior teeth. Patient-related variables need evaluation to select the appropriate retainer, while patients ought to realize the importance of retention and comply with offered guidance. Overall, the orthodontist is responsible for keeping the patient informed on the properties and the duration of retention, even before starting active orthodontic treatment.

Mandibular protrusion and its treatment is challenging for the orthodontist. The aim of the present research was to identify macroscopic changes in the mandible, based on three-dimensional Cone Beam Computed Tomography analysis. Seventy-two male Wistar rats were divided into two equal groups, experimental (group A) and control (group B). Each consisted of three equal subgroups of 12 rats (A1, A2, A3, B1, B2, B3). Full-cast orthodontic intraoral devices were attached to the maxillary incisors of the experimental animals, and effected functional posterior mandibular displacement. Throughout the experimental period, all animals were fed with mashed food. Animals were sacrificed at 30 days (A1, B1), 60 days (A2, B2) and 90 days (A3, B3). At the 60th day of the experiment, the orthodontic devices were removed from the remaining experimental subgroup A3. Measurements revealed significant differences in the anteroposterior dimensions between experimental and control subgroups. However, the observed changes in the vertical dimensions, Condylion/Go’–Menton and the Intercondylar distance proved insignificant. Posterior mandibular displacement of the mandible in growing rats affects the morphology of the mandible and culminates in the development of a smaller mandible at a grown age.

Treating extreme mandibular growth is challenging. The mandible is pushed backwards to address itsprotrusion. Nevertheless, conclusions after such displacement in animals have been contradictory. The aim of the present review is to present measurable alterations of the mandible and the condyle following retractionin healthy rats or rabbits. PubMed, Scopus and Web of Science were accessed for relevant studies up to October 2020. Eligibility was determined by the PICOS process, while the risk of bias was estimated with SYRCLE’s risk of bias tool. Retraction resulted in a more distal molar occlusion and the condyle rested more posteriorly. Mandibular anteroposterior bilateral growth restriction was achieved, the condylar process measured smaller and its angulation increased. The condylar neck thickened, its posterior surface flattened, the coronoid process was measured longer, and enlarged retromolar density was registered. Differences in the ramus height and the intercondylar distance were insignificant. Changes persisted for the period of study and subsequently the mandible resumed its inherited growth pattern. The timing of mandibular shaping and TMJ outcomes might depend on the properties of the applied force. Stability is of concern and well-structured, long-term studies are expected to resolve the issue and further clarify the results of posterior mandibular displacement.

Background: Biotechnology shows a promising future in bridging the gap between biomedical basic sciences and clinical craniofacial practice. The purpose of the present review is to investigate the applications of biotechnology in the craniofacial complex. Methods: This critical review was conducted by using the following keywords in the search strategy: “biotechnology”, “bioengineering”, “craniofacial”, “stem cells”, “scaffolds”, “biomarkers”, and ”tissue regeneration”. The databases used for the electronic search were the Cochrane Library, Medline (PubMed), and Scopus. The search was conducted for studies published before June 2022. Results: The applications of biotechnology are numerous and provide clinicians with the great benefit of understanding the etiology of dentofacial deformities, as well as treating the defected areas. Research has been focused on craniofacial tissue regeneration with the use of stem cells and scaffolds, as well as in bioinformatics with the investigation of growth factors and biomarkers capable of providing evidence for craniofacial growth and development. This review presents the biotechnological opportunities in the fields related to the craniofacial complex and attempts to answer a series of questions that may be of interest to the reader. Conclusions: Biotechnology seems to offer a bright future ahead, improving and modernizing the clinical management of cranio-dento-facial diseases. Extensive research is needed as human studies on this subject are few and have controversial results.

Skeletal Class II malocclusion is the most common skeletal anomaly in orthodontics. Growth in the body of the deficient mandible is induced by periosteal apposition and endochondral ossification in the condyle. Functional appliances have been used in the correction of Class II malocclusions by inducing mandibular growth. Despite their utilization though, their effect still remains controversial. The aim of the present study is to review the existing literature regarding the effects of mandibular protrusion in mandibular growth of growing rats. A protocol was followed according to the guidelines of the Cohrane Handbook for Systematic Reviews. Databases were searched using a specific algorithm. From the ten studies finally analyzed, we conclude that the use of a functional appliance in growing rats induces cell proliferation and bone formation in their condyles, resulting in mandibular growth.

The present study aimed to investigate any biochemical and histological changes of the rat condyle and mandible in animals that had sustained mandibular growth restriction. Seventy-two male Wistar rats were divided into two equal groups, experimental and control. Each group consisted of three equal subgroups. The animals were sacrificed 30, 60, and 90 days after the start of the experiment. Blood samples were collected from the eye, and the osteoprotegerin (OPG), Receptor Activator of Nuclear Factor Kappa B Ligand (RANKL), and Macrophage Colony-Stimulating factor (MCSF)concentrations were measured by using enzyme-linked immunosorbent assay (ELISA) kits. A histological analysis was performed on the mandibular condyles. The blood serum values of OPG, RANKL, and MCSF did not exhibit any statistically significant difference between groups or subgroups. However, significant histological changes became evident after a histomorphometric condylar examination was performed. The Bone Surface/Total Surface ratio appeared reduced in the anterior and posterior regions of the condyle. In addition, the Posterior Condylar Cartilage Thickness was measured and determined to be significantly diminished. The present intervention that employed orthodontic/orthopedic devices did not prove to have any significant effect on the circulating proteins under study. Posterior displacement of the mandible may culminate only in local histological alterations in condylar cartilage thickness and its osseous microarchitecture.

The purpose of this article is to present a computer designed and 3D-printed metal device, which was used for the surgical exposure and orthodontic treatment of maxillary palatally impacted canines. In two cases which presented a palatally impacted canine, a Cone-Beam Computed Tomography (CBCT) was acquired and an intraoral scanning was performed, to determine the exact location of the canine. Based on a digital model, a device leaning on the teeth and mucosa was designed to serve as a guiding tool for the oral surgeon to expose the crown of the canine and help the orthodontist to provide proper traction. The device was then 3D-printed in biocompatible dental alloy and placed in the patients’ mouth. After the surgical exposure of the canine’s crown in both cases, a gold chain apparatus was bonded on and it was mounted on the metal projection of the device through an elastic chain. Within 3 months of traction, the crown of the canines appeared in the patients’ palate to the exact location that was predicted and guided. A 3D-designed and manufactured metal device, with information acquired by CBCT and intraoral scanning, can be used for the exposure and traction of palatally impacted canines.