Mechanobiology of orthodontic tooth movement: An update.

The purpose of this review is to provide an update on the changes at the cellular and tissue level occurring during orthodontic force application. For the understanding of this process, knowledge of the mechanobiology of the periodontal ligament and the alveolar bone are essential. The periodontal ligament and alveolar bone make up a functional unit that undergoes robust changes during orthodontic tooth movement.

Age effect on orthodontic tooth movement rate and the composition of gingival crevicular fluid : A literature review.

Purpose: To evaluate and form a comprehensive understanding of the effect of patient age on bone remodeling and consequently on the rate of orthodontic tooth movement (OTM).

Methods: A systematic search in PubMed and Embase from 1990 to December 2017 was performed and completed by a hand search. Prospective clinical trials which investigated the rate of OTM and/or studies assessing age-related changes in the composition of gingival crevicular fluid (GCF) in older compared to younger study groups were included.

Update on 13 Syndromes Affecting Craniofacial and Dental Structures.

Care of individuals with syndromes affecting craniofacial and dental structures are mostly treated by an interdisciplinary team from early childhood on. In addition to medical and dental specialists that have a vivid interest in these syndromes and for whom these syndromes are of evident interest, experts of scientific background-like molecular and developmental geneticists, but also computational biologists and bioinformaticians-, become more frequently involved in the refined diagnostic and etiological processes of these patients. Early diagnosis is often crucial for the effective treatment of functional and developmental aspects.

Orthodontic Forces Induce the Cytoprotective Enzyme Heme Oxygenase-1 in Rats.

Orthodontic forces disturb the microenvironment of the periodontal ligament (PDL), and induce craniofacial bone remodeling which is necessary for tooth movement. Unfortunately, orthodontic tooth movement is often hampered by ischemic injury and cell death within the PDL (hyalinization) and root resorption. Large inter-individual differences in hyalinization and root resorption have been observed, and may be explained by differential protection against hyalinization.

Age-related changes of dental pulp tissue after experimental tooth movement in rats.

It is generally accepted that the effect of orthodontic tooth movement on the dental pulp in adolescents is reversible and that it has no long-lasting effect on pulpal physiology. However, it is not clear yet if the same conclusion is also valid for adult subjects. Thus, in two groups of rats, aged 6 and 40 weeks respectively, 3 molars at one side of the maxilla were moved together in a mesial direction with a standardized orthodontic appliance delivering a force of 10 cN.

Delayed cutaneous wound closure in HO-2 deficient mice despite normal HO-1 expression.

Impaired wound healing can lead to scarring, and aesthetical and functional problems. The cytoprotective haem oxygenase (HO) enzymes degrade haem into iron, biliverdin and carbon monoxide. HO-1 deficient mice suffer from chronic inflammatory stress and delayed cutaneous wound healing, while corneal wound healing in HO-2 deficient mice is impaired with exorbitant inflammation and absence of HO-1 expression.

The oxytalan fibre network in the periodontium and its possible mechanical function.

The biomechanical character of the periodontal ligament (PDL) is crucial in its response to functional and orthodontic forces. Collagen has been the primary subject of investigations in this field. Several studies, however, indicate that oxytalan fibres, which belong to the elastic fibre family, also contribute to the biomechanical character and behaviour of the PDL.

Inflammatory responses in two commonly used rat models for experimental tooth movement: comparison with ligature-induced periodontitis.

Objective: To compare two often used rat models for experimental tooth movement, namely the elastic band, and the coil spring model. They were compared with a silk-ligature-induced periodontitis model.

Design: Thirty six, 6-weeks-old rats were used.

Dentoalveolar development in beagle dogs after palatal repair with a dermal substitute.

Introduction: Our aim was to compare the dentoalveolar development in beagle dogs after palatal repair according to the Von Langenbeck technique with and without implantation of a dermal substitute.

Methods: Nineteen beagles (age, 12 weeks) were assigned to 2 experimental groups and an untreated control group. Palatal surgery was performed with the Von Langenbeck technique in the 2 experimental groups.

Osteoclast differentiation and recruitment during early stages of experimental tooth movement in rats.

Osteoclasts are derived from macrophage-lineage precursors. ED1 is an antibody that can recognize this lineage of cells. Matrix metalloproteinase 9 (MMP9) is essential for the migration of osteoclasts and their precursors during osteoclastogenesis.

Medication effects on the rate of orthodontic tooth movement: a systematic literature review.

Introduction: Recently, several reviews have been published on the effects of medications on bone physiology and the clinical side effects in orthodontics. However, the effects of medications on the rate of orthodontic tooth movement have not been evaluated.

Methods: A systematic literature review on the effects of medications and dietary supplements on the rate of experimental tooth movement was performed by using PubMed (1953-Oct 2007), Web of Science, and Biosis, complemented by a hand search.

Age-related changes of periodontal ligament surface areas during force application.

Objective: To investigate the age-dependent morphology of the periodontal ligament (PDL) tissue and changes in its surface area (SA) during force application provided with a standardized orthodontic setup for a period of 12 weeks in young and adult rats.

Methods: Two groups of 30 rats, age 6 weeks and 9 to 12 months, were used. Orthodontic appliances were placed to move the maxillary molars mesially with the contralateral sides used as controls.

Putative golden proportions as predictors of facial esthetics in adolescents.

Introduction: In orthodontics, facial esthetics is assumed to be related to golden proportions apparent in the ideal human face. The aim of the study was to analyze the putative relationship between facial esthetics and golden proportions in white adolescents.

Methods: Seventy-six adult laypeople evaluated sets of photographs of 64 adolescents on a visual analog scale (VAS) from 0 to 100.

Osteoclast differentiation during experimental tooth movement by a short-term force application: an immunohistochemical study in rats.

Objective: The origin of osteoclasts responsible for bone resorption during orthodontic tooth movement is not yet clear. Their precursors may reside within the periodontal ligament (PDL) or could be recruited from the circulation or the bone marrow. The aim of this study was to investigate the spatial and sequential distribution of osteoclast precursors during experimental tooth movement by using three differentiation markers: receptor for macrophage colony stimulating factor (c-Fms), receptor activator of nuclear factor-kappaB (RANK), and calcitonin receptor (CTR).

Effect of duration of force application on blood vessels in young and adult rats.

Introduction: Age effects on orthodontically induced periodontal vascular reactions have not been studied. The aim of the present study was to test the hypothesis that prolonged tooth movement induces age-related increases in periodontal vascularity.

Methods: A standardized orthodontic appliance was placed in 2 groups of 30 rats aged 6 weeks and 9 to 12 months.

Age-dependent external root resorption during tooth movement in rats.

Objective: To investigate the effect of age on root resorption and distribution along different parts of the root during prolonged light force application.

Material And Methods: Orthodontic appliances were placed in two groups of 30 rats (one group 6 weeks old, the other 9-12 months old), with contralateral sides as controls. Groups of animals were killed at 1, 2, 4, 8, and 12 weeks.

Panel perception of change in facial aesthetics following orthodontic treatment in adolescents.

The aim of the study was to evaluate the influence of the characteristics of panel members, the effects of gender and Angle Class of adolescent patients on their change in facial aesthetics following orthodontic treatment, and to assess the optimal panel size for epidemiological studies on changes in facial aesthetics after orthodontic treatment. A panel of 74 adult laymen (35 males and 39 females) and a panel of 87 orthodontists (37 males and 50 females) evaluated sets of three post-treatment standardized photographs (one frontal, one three-quarter smiling, and one lateral) of 64 adolescent orthodontic patients in relation to the pre-treatment sets of the same patient on a five-point scale. The main effects of professional background, age, gender, and geographic region of the panel members on the aesthetic scores, as well as their first order interactions were evaluated by multilevel models.

Facial esthetics in adolescents and its relationship to "ideal" ratios and angles.

Introduction: Many guidelines, norms, and ideal ratios and angles for attractive faces have been proposed in the literature. The aim of this study was to test the hypothesis that facial attractiveness in adolescents is related to ideal angles and ratios, as indicated in the literature.

Methods: Seventy-six laypeople viewed sets of photographs of 64 adolescents and rated them on a visual analog scale (VAS) from 0 to 100.

Tooth movement characteristics in relation to root resorption in young and adult rats.

The aim of this study was to investigate tooth movement characteristics in relation to root resorption in young and adult rats. Two groups of 30 rats each (aged 6 wk and 9-12 months, respectively) were used. Standardized orthodontic appliances were placed to move the maxillary molars mesially.

Implantation of tissue-engineered mucosal substitutes in the dog palate.

Tissue shortage complicates the surgery of cleft palate (CP) anomalies. The healing of defects on the palate impairs growth of the dento-maxillary complex due to scar tissue formation. Implantation of grafts into the wound area might reduce this adverse effect of surgery.

Evaluation of a collagen-glycosaminoglycan dermal substitute in the dog palate.

Tissue shortage complicates surgery of cleft lip and palate. The healing of defects on the palate impairs growth of the dentoalveolar complex because of scar tissue formation. Implantation of a matrix into the wound might overcome this adverse effect.

Cytokeratin expression in palatal and marginal mucosa of cleft palate patients.

Objective: The margin of a palatal cleft is a unique anatomical site since the palatal mucosa is continuous with the nasal or nasopharyngeal mucosa. The aim of this study was to compare the expression patterns of cytokeratins and basal membrane components of the mucosa in the area of the cleft.

Design: Biopsies from the mucosa of the hard palate and from the cleft margin in the soft palate were obtained from five patients during the primary surgical closure of the cleft.

In vitro migration and adhesion of fibroblasts from different phases of palatal wound healing.

Cleft palate patients often show mid-facial growth impairment after surgical closure of the defect. This is a consequence of palatal wound healing, and more specifically of wound contraction and scar tissue formation. Cells of the fibroblast lineage are responsible for these processes and they display different phenotypes in the course of the wound healing process.

The influence of the sagittal split osteotomy on the condylar cartilage structure and the subchondral vascularization of the temporomandibular joint: a preliminary study in goats.

Objective: The concern that a sagittal split osteotomy of the mandibular ramus could compromise the subchondral vascularization and especially the venous outflow in the condylar area, which in turn could influence the structure of the condylar cartilage, prompted this preliminary study on goats.

Study Design: A sagittal split osteotomy was performed in the mandibular ramus at 1 side in each of 6 young adult goats. The contralateral side served as control.