Michael Wolf

Background: Digital approaches have fundamentally transformed orthodontics. This study compares an automated, rule-based algorithm with manual landmark placement, evaluating the results of manual versus semi-automated orthodontic quality indices. Methodology: This retrospective method-comparison study evaluated 100 digital models from 50 orthodontic patients using the Onyxceph3™ diagnostic software. Primary automated landmark placement was assessed for four predefined dental landmark types across 14 tooth groups and was then compared with expert-based manual landmark placement, which was used as the reference standard. Deviations were quantified using Euclidean distances and signed coordinate differences along the X-, Y- and Z-axes. Secondly, we evaluated semi-automated versus manual orthodontic quality assessment using the ABO eCRE and PAR index. Results: Cusps and incisal landmarks show low levels of error when using automatic placement compared with manual placement, with a threshold of ≤1 mm. Vestibular marginal gingival landmarks show the highest deviation. Across tooth groups, mean deviations ranged from 0.54 mm for second molars (95% CI 0.49–0.59) to 0.83 mm for canines (95% CI 0.80–0.85). There was no relevant global directional bias in the X-, Y- and Z-axes. Secondary analysis revealed mean differences of 1.90 points and 3.98 points for ABO eCRE, and −0.08 points and 0.74 for PAR in initial and final models, respectively. Conclusion: The automatic placement of landmarks generally showed acceptable deviations, with the exception of vestibular marginal gingival landmarks. However, the automatic detection of landmarks and orthodontic indices should always be reviewed by a clinician.

Background: Periodontal remodeling is a continuous, adaptive process essential for maintaining the structural and functional integrity of periodontal tissues. While external factors such as bacterial biofilm, excessive forces, and poor oral hygiene are recognized triggers of periodontal pathologies, they do not fully explain their persistent prevalence. Objective: This opinion paper emphasizes the impact of systemic diseases on periodontal homeostasis and considers periodontal disease as a manifestation of systemic dysfunction rather than solely a bacterial local disease. Methods: This paper is conceptually designed as a narrative review and synthesizes the molecular and cellular mechanisms through which systemic diseases converge to disrupt periodontal remodeling. Results: Emerging evidence underscores the critical role of systemic diseases, including chronic kidney disease, cardiovascular disease, liver dysfunction, and hematologic malignancies, in addition to studied uncontrolled diabetes mellitus, in destabilizing periodontal homeostasis. These systemic conditions are all associated with excess systemic inflammation that impairs regenerative capacity, mineralization, vascularity, and immune responses, fostering a subclinical environment prone to periodontal tissue pathologies with clinical impact. This opinion paper is conceptually designed as a narrative review and synthesizes the molecular and cellular mechanisms through which systemic diseases converge to disrupt periodontal remodeling, including periodontal pathologies as a consequence of systemic dysfunction rather than a purely bacterially induced local disease. Conclusion: Clinically, this understanding demands intensified dental surveillance to uncover modifiers of susceptibility and interdisciplinary care for systemically compromised patients. Future research should identify early biomarkers of systemic impact and inform strategies that integrate oral and systemic health to reduce the periodontal disease burden.

Background: Precise orthodontic pre-surgical decompensation is a critical prerequisite for optimal outcomes in orthognathic surgery. However, the relative effectiveness of completely customized lingual appliances (CCLAs) versus prefabricated vestibular multibracket appliances (PVMAs) remains insufficiently established. This study compared the decompensation efficiency, treatment quality, and overall clinical performance of these two appliances. Methodology: The study included 60 consecutive patients who underwent orthodontic-orthognathic surgery: 30 with CCLA and 30 with PVMA. To ensure quality, the digital ABO CRE for each scanned model was evaluated using OnyxCeph3™ diagnostic software, and the efficiency of each appliance was recorded in the respective patient files. Both groups underwent the same evaluation protocol involving initial, intermediate (pre-surgery) and final casts. An additional set-up model was included for the CCLA group only. Results: Both groups exhibited comparable baseline scores (mean difference 5.83; 95% CI 1.69 to 9.98). CCLAs demonstrated lower ABO scores than the PVMA group after the decompensation phase (mean difference − 9.23; 95% CI -13.38 to -5.09) and in the final assessment (mean difference − 9.30; 95% CI − 13.44 to -5.16). The largest differences between groups were observed for the alignment criteria in both jaws at the intermediate and final assessments, as well as for all intermaxillary criteria. Treatment efficiency particularly during the decompensation phase, was significantly improved in the CCLA group. Conclusion: CCLAs demonstrated superior efficiency and higher treatment quality compared with PVMAs in patients undergoing combined orthodontic–orthognathic therapy. The use of CCLAs in combination with orthognathic surgery appears to represent a high-quality treatment approach for correcting pronounced skeletal discrepancies and may serve as a reliable alternative to PVMA in appropriately selected patients.

Hypercementosis has been previously reported in mice lacking progressive ankylosis protein (Ank KO mice, or Ank, KO - knockout, WT - wildtype) due to decreased levels of the mineralization inhibitor inorganic pyrophosphate. However, the impact of hypercementosis on alveolar bone remodeling and periodontal ligament (PDL) maintenance from orthodontic forces during orthodontic tooth movement (OTM) remains unclear. To investigate the roles of ANK protein on tooth movement, PDL maintenance, alveolar bone remodeling, and tooth root resorption, we performed a split-mouth model of OTM induced by a closed-coil spring stretched between the maxillary first molar and maxillary incisors in Ank KO and WT mice (including both males and females). Micro-computed tomographic analysis revealed a 36.6% reduction in OTM in Ank KO mice compared with WT mice, although OTM-induced thickening of PDL was found to be similar in both groups. While reduced tissue mineral density (TMD) of the alveolar bone was observed in WT mice, TMD in Ank KO mice was maintained. Loss of Ank leads to wider roots with thicker cementum on the untreated, contralateral side, whereas a significant increase in OTM-induced root resorption was observed on the lateral tension side. Histologic analysis of root resorption confirmed these data and showed increased resorption lacunae located prevalently in the OTM tooth root cementum of Ank KO mice. Using a quantitative PCR array of bone-associated markers to interrogate total RNA harvested from PDL tissues along the root surface, we found alterations in gene expression from OTM in both WT and Ank KO mice, which included genes involved in bone remodeling, calciotropic hormones and receptors, cytokines, growth factors, and receptors. Our findings advance the understanding of the role of Ank in regulating mineralization in the periodontium as well as factors involved in root resorption.

Aims: Patients with chronic kidney disease (CKD) show a high risk of cardiovascular diseases, predominantly caused by accelerated vascular calcification. Vascular calcification is a highly regulated process with no current treatment. The vasoconstriction-inhibiting factor (VIF) peptide was recently discovered with vasoregulatory properties, but no information regarding calcification has been described. Methods and results: In the present work, the inhibitory calcification effect of the VIF peptide was analysed in vitro in vascular smooth muscle cells (VSMCs), ex vivo in rat aortic rings, as well as in vivo in rats treated with vitamin D and nicotine (VDN). The VIF peptide inhibits vascular calcification by acting as a calcimimetic for the calcium-sensing receptor, increasing carboxylated matrix Gla protein production and blocking the activation of calcification pathways. The VIF peptide decreased calcium influx, the production of reactive oxygen species, and the activation of multiple kinases in VSMCs. Furthermore, calcium deposition in the aortas of patients with CKD negatively correlates with the VIF peptide concentration. Moreover, we show the cleavage of the VIF peptide from chromogranin-A by ‘proprotein convertase subtilisin/kexin type 2’ and ‘carboxypeptidase E’ enzymes. In addition, ‘cathepsin K’ degrades the VIF peptide. The active site of the native 35 amino acid-sequence long VIF peptide was identified with seven amino acids, constituting a promising drug candidate with promise for clinical translation. Conclusion: The elucidation of the underlying mechanism by which the VIF peptide inhibits vascular calcification, as well as the active sequence and the cleavage and degradation enzymes, forms the basis for developing preventive and therapeutic measures to counteract vascular calcification.

Orthodontic tooth movement (OTM) is a complex process involving bone remodeling, and is regulated by various molecular factors, including microRNAs (miRNAs). These small, non-coding RNAs are critical in post-transcriptional gene regulation and have been implicated in the modulation of osteoclast and osteoblast activity during OTM. This study aimed to explore the expression profiles of salivary exosome-derived miRNAs during OTM to identify potential biomarkers that could provide insights into the biological processes involved in orthodontic tooth movement. Saliva samples were collected from 15 patients at three time points: before treatment (Day 0), 7 days after the treatment’s onset (Day 7), and 40 days after the treatment’s onset (Day 40). The exosomes were isolated, and the miRNAs were extracted and sequenced. A differential expression analysis and gene ontology (GO) enrichment were performed to identify the miRNAs involved in osteoblast and osteoclast differentiation. Out of the 1405 detected miRNAs, 185 were analyzed. Several miRNAs were associated with bone-remodeling processes. The statistically significant finding was the downregulation of hsa-miR-4634 after 40 days of treatment. These findings contribute to the understanding of miRNA regulation in orthodontics and may have broader implications for skeletal disorders, such as osteoporosis.

Leypold T, et al. J Periodontal Implant Sci. 2024 Jul;54:e21. https://doi.org/10.5051/jpis.2303680184

Background/Objectives: Initial sterile inflammation is an essential molecular process in the periodontium during orthodontic tooth movement. A better understanding and possible modulations of these processes are of great interest to develop individual therapies for special patient groups. The prenylated plant polyphenol xanthohumol (XN) could have modulating effects as it has shown anti-inflammatory and angiogenesis-inhibiting effects in various cell lines. This study investigated the anti-inflammatory properties of XN in an in vitro model of compressively stimulated human periodontal ligament stem cells (hPDLSCs), which have a different function in the periodontium than the previously used cementoblasts. Methods: The expression of inflammatory markers at the mRNA and protein levels and the regulation of central kinases were investigated. Results: XN showed a dose-dependent influence on cell viability. Low concentrations between 0.2 and 4 µM showed positive effects, while 8 µM caused a significant decrease in viability after 24 h. Mechanical stimulation induced an upregulation of pro-inflammatory gene (IL-6, COX2) and protein (IL-6) expression. Here, XN significantly reduced stimulation-related IL-6 mRNA and gene expression. Furthermore, the phosphorylation of AKT and ERK was upregulated by mechanical stimulation, and XN re-established phosphorylation at a level similar to the control. Conclusions: We demonstrated a selective anti-inflammatory effect of XN in hPDLSCs. These findings provide the basis for further investigation of XN in the modulation of inflammatory responses in orthodontic therapy and the treatment of periodontal inflammation.