Lateral cephalometric parameters among Arab skeletal classes II and III patients and applying machine learning models.

Background: The World Health Organization considers malocclusion one of the most essential oral health problems. This disease influences various aspects of patients' health and well-being. Therefore, making it easier and more accurate to understand and diagnose patients with skeletal malocclusions is necessary.

The Complexity of Skeletal Transverse Dimension: From Diagnosis, Management, and Treatment Strategies to the Application of Collaborative Cross (CC) Mouse Model.

This study investigates the significance of skeletal transverse dimension (STD) in orthodontic therapy and its impact on occlusal relationships. The primary goal is to enhance understanding and promote the integration of transverse skeletal diagnostics into routine orthodontic assessments. To achieve this aim, the study employs a comprehensive approach, utilizing model analysis, clinical assessments, radiographic measurements, and occlusograms.

Impact of Mechanical Strain and Nicotinamide on RUNX2-Deficient Osteoblast Mimicking Cleidocranial Dysplasia.

Cleidocranial dysplasia (CCD) is a rare genetic defect caused by a heterozygous mutation of runt-related transcription factor 2 (RUNX2), which is important for osteoblast and skeletal development. RUNX2-deficiency causes extra- and intra-oral malformations that often require orthodontic treatment. Nicotinamide (NAM) affects bone remodelling processes.

Anterior Open Bite Malocclusion: From Clinical Treatment Strategies towards the Dissection of the Genetic Bases of the Disease Using Human and Collaborative Cross Mice Cohorts.

Anterior open bite malocclusion is a complex dental condition characterized by a lack of contact or overlap between the upper and lower front teeth. It can lead to difficulties with speech, chewing, and biting. Its etiology is multifactorial, involving a combination of genetic, environmental, and developmental factors.

Validation of a mathematical-geometrical model to calculate the length of an individual anterior arch.

Purpose: For resolving anterior dental crowding or spacing, it is of key interest in personalised orthodontic diagnostics and treatment planning to predict the extent of space gained or lost in the anterior dental arch by changing incisor inclination or position. To facilitate the determination of anterior arch length (AL) and to predict its alterations following tooth movements, a mathematical-geometrical model, based on a third-degree parabola, was established. The aim of this study was to validate this model and assess its diagnostic precision.

Association between craniofacial patterns and third molar agenesis in orthodontic patients.

Purpose: Third molar agenesis (TMA) is the most common craniofacial anomaly and has been associated with craniofacial patterns in different populations. Therefore, the aim of this retrospective cross-sectional study was to assess a possible association between craniofacial patterns and TMA in German orthodontic patients.

Methods: Patients undergoing orthodontic treatment with dental records including anamnesis, pretreatment lateral cephalograms and orthopantomograms were evaluated.

Comparative treatment outcomes after bilateral extractions of maxillary second molars or first premolars in patients with class II malocclusion: a retrospective study.

Background: This retrospective cohort study aimed to compare treatment results between bilateral extraction of upper second molars (M2) and first premolars (P1) in terms of treatment timing, cephalometry, upper third molar alignment and relapse in the long-term.

Methods: Fifty-three consecutively treated Caucasian patients with a brachyfacial pattern, skeletal class I and dental class II requiring extraction in the maxilla due to crowding were retrospectively divided into group I (M2 extracted; N = 31) and II (P1 extracted; N = 22). Fixed appliances were inserted after extraction and after distalisation of the first molars in group I.

Association between genetic variants in key vitamin-D-pathway genes and external apical root resorption linked to orthodontic treatment.

This study evaluated the association between single-nucleotide polymorphisms (SNPs) in vitamin-D-related genes and the amount of external apical root resorption linked to orthodontic treatment. One hundred and forty-three individuals were assessed. The amount of external apical root resorption of upper central incisors (EARR ) and lower first molars (EARR ) were evaluated in radiographs.

Impact of PIEZO1-channel on inflammation and osteoclastogenesis mediated via periodontal ligament fibroblasts during mechanical loading.

The identification of mechanosensitive ion channels and their importance in innate immunity provides new starting points to elucidate the molecular mechanisms of orthodontic tooth movement. The mechanosensitive electron channel PIEZO1 (Piezo Type Mechanosensitive Ion Channel Component 1) may play a crucial role in orthodontic tooth movement. To investigate the role of the PIEZO1 channel, periodontal ligament fibroblasts (PDLF) were subsequently treated with a PIEZO1 inhibitor (GsMTx) with simultaneous pressure application or with an activator (JEDI2) without mechanical strain.

Relapse in class II orthognathic surgery: a systematic review.

Objectives: Relapse after orthognathic surgery seems to depend on diverse factors. Proffit et al. postulated in 2007 a "hierarchy of stability" (Head Face Med 6:66, 2007), ranking posttreatment stability after various orthognathic procedures, but no systematically reviewed evidence was provided.

Impact of Melatonin on RAW264.7 Macrophages during Mechanical Strain.

The concentration of melatonin is elevated during the night when patients mainly wear removable orthodontic appliances. Next to periodontal ligament fibroblasts and osteoblasts, macrophages react to mechanical strain with an increased expression of inflammatory mediators. Here, we investigated the impact of melatonin on RAW264.

Individual dental and skeletal age assessment according to Demirjian and Baccetti: Updated norm values for Central-European patients.

Purpose: Chronological age often differs from dental and skeletal age. With orthopantomograms and lateral cephalograms, dental and skeletal development can be determined according to the methods published by Demirjian et al. and Baccetti et al.

Impact of Leptin on the Expression Profile of Macrophages during Mechanical Strain In Vitro.

Childhood obesity is a growing problem in industrial societies and associated with increased leptin levels in serum and salvia. Orthodontic treatment provokes pressure and tension zones within the periodontal ligament, where, in addition to fibroblasts, macrophages are exposed to these mechanical loadings. Given the increasing number of orthodontic patients with these conditions, insights into the effects of elevated leptin levels on the expression profile of macrophages during mechanical strain are of clinical interest.

Single Nucleotide Polymorphisms in Is Associated with Persistent Primary Tooth and Delayed Permanent Tooth Eruption.

Persistent primary tooth (PPT) is a prevalent clinical condition that occurs when a primary tooth is over-retained beyond the established period of its normal exfoliation time, remaining in the oral cavity. Many factors could be involved in the risk of PPT; therefore, the aim of this study was to evaluate if single nucleotide polymorphisms (SNPs) in the gene are associated with PPT. Children undergoing orthodontic treatment were screened.

Dietary salt and myeloid NFAT5 (nuclear factor of activated T cells 5) impact on the number of bone-remodelling cells and frequency of root resorption during orthodontic tooth movement.

Purpose: The aim of the study was to investigate the impact of dietary salt and the osmoprotective transcription factor nuclear factor of activated T cells 5 (NFAT5) in myeloid cells on bone remodelling cells as osteocytes, osteoblasts and osteoclasts and on force-induced dental root resorptions in a mouse model.

Methods: Control mice and mice lacking myeloid NFAT5 (nuclear factor of activated T cells 5) were either kept on low, normal or high salt diets. After one week on the specified diet an elastic band was inserted between the first and second molar to induce orthodontic tooth movement.

Association of third molar agenesis and microdontia with genetic polymorphisms in vitamin-D-related genes.

The present study aimed to evaluate if functional genetic polymorphisms in vitamin-D-related genes are associated with third molar agenesis and third molar microdontia in German orthodontic patients. Pre-orthodontic and follow-up treatment records were evaluated for phenotype definition. Saliva samples were collected for DNA extraction.

Ideal transverse position of mandibular first molars based on CBCT-derived alveolar bone coverage.

Background: In orthodontic treatment, transverse arch width often needs to be adjusted to correct anomalies such as posterior crossbite. Ideal transverse arch width at the first molars enabling long-term stability and periodontal health, however, requires sufficient posttreatment bony coverage buccally and orally of the tooth roots. Thus, the aim of this retrospective study was to determine the physiological alveolar bone thickness at the buccal and oral roots of the first mandibular molars in the general population using human CBCT scans assessing local and gender-specific differences.

Exploring the Association Between Genetic Polymorphisms in Genes Involved in Craniofacial Development and Isolated Tooth Agenesis.

Tooth agenesis is a common congenital anomaly in humans and is more common in oral cleft patients than in the general population. Many previous studies suggested that oral cleft and tooth agenesis share a similar genetic background. Therefore, this study explored the association between isolated tooth agenesis and genetic polymorphisms in genes that are crucial for craniofacial and tooth development.

Assessing the association between vitamin D receptor and dental age variability.

Objectives: To explore the association between genetic polymorphisms in vitamin D receptor (VDR), vitamin D serum levels, and variability in dental age.

Material And Methods: This cross-sectional study was based on an oral examination, panoramic radiograph analysis, and genotype analysis from biological samples. Dental age was evaluated using two different methods: Demirjian et al.

Effects of mechanical strain on periodontal ligament fibroblasts in presence of Aggregatibacter actinomycetemcomitans lysate.

Purpose: Many adult orthodontic patients suffer from periodontitis, which is caused by oral pathogens such as the gram-negative Aggregatibacter actinomycetemcomitans (Agac). Like orthodontic tooth movement, periodontitis is associated with inflammation and alveolar bone remodelling thereby affecting orthodontic treatment. Interactions of both processes, however, are not sufficiently explored, particularly with regard to oxidative stress.

Myeloid HIF1α Is Involved in the Extent of Orthodontically Induced Tooth Movement.

During orthodontic tooth movement, transcription factor hypoxia-inducible factor 1α (HIF1α) is stabilised in the periodontal ligament. While HIF1α in periodontal ligament fibroblasts can be stabilised by mechanical compression, in macrophages pressure application alone is not sufficient to stabilise HIF1α. The present study was conducted to investigate the role of myeloid HIF1α during orthodontic tooth movement.

Floating norms for individualising the ANB angle and the WITS appraisal in orthodontic cephalometric analysis based on guiding variables.

Purpose: The sagittal skeletal relationship of maxilla and mandible (skeletal class) can generally be determined via lateral cephalograms (ANB angle or Wits appraisal) by comparing measurements to empirical norms based on the respective population mean. However, values differing from these empirical norms also enable a therapeutically desired, normal class I occlusion depending on individual craniofacial pattern, thus requiring floating norms based on guiding variables. As available regression equations consider only few predictor variables and are not up-to-date regarding a contemporary patient collective, the aim of this study was to establish improved and extended regression equations for individualising the ANB angle and Wits appraisal.

Impact of Leptin on Periodontal Ligament Fibroblasts during Mechanical Strain.

Orthodontic treatment to correct dental malocclusions leads to the formation of pressure zones in the periodontal ligament resulting in a sterile inflammatory reaction, which is mediated by periodontal ligament fibroblasts (PDLF). Leptin levels are elevated in obesity and chronic inflammatory responses. In view of the increasing number of orthodontic patients with these conditions, insights into effects on orthodontic treatment are of distinct clinical relevance.

Genetic variants in bone morphogenetic proteins signaling pathway might be involved in palatal rugae phenotype in humans.

This study investigated, if genetic variants in BMP2, BMP4 and SMAD6 are associated with variations in the palatal rugae pattern in humans. Dental casts and genomic DNA from 75 patients were evaluated. Each patient was classified as follows: total amount of rugae; bilateral symmetry in the amount, length and shape of the palatal rugae; presence of secondary or fragmentary palatal rugae; presence of unifications; predominant shape; and predominant direction of the palatal rugae.