INTRODUCTION: The primary aim of this study was to assess the amount and long-term stability of orthodontically created bone in patients with agenesis of maxillary lateral incisors after canine distalization. The secondary aim was to explore the impact of patient age on the process of alveolar bone resorption. METHODS: A group of patients with agenesis of the maxillary permanent lateral incisor was examined at 4 time points: the beginning of orthodontic treatment (T1, n = 80), the end of treatment (T2, n = 80), 2-5 years after treatment (T3, n = 79), and 12-15 years after treatment (T4, n = 32). The width of the edentulous alveolar bone was measured from study casts at the level of the bone ridge (point A) and 5 mm apically from the alveolar ridge (point B). Alveolar ridge height was also recorded using panoramic radiographs at all time points. Paired t tests, 2-sample t tests, Friedman test with Bonferroni correction, Spearman`s correlation, and linear regression tests were used to analyze the data. RESULTS: The alveolar ridge width was reduced by an average of 0.44 mm at point A and 0.47 mm at point B during the 12-15 years after treatment (T2-T4) and by 0.21 mm and 0.19 mm during the last 10 years (T3-T4). The alveolar ridge height was reduced by 0.59 mm between T2 and T4 and by 0.05 mm between T3 and T4. All reductions in ridge width and height were statistically significant (P <0.05). However, no significant correlation was observed between patient age and changes in alveolar bone parameters (P >0.05). CONCLUSIONS: Although the reductions in alveolar ridge dimensions were statistically significant, the orthodontically created bone after canine distalization remained stable 12-15 years after treatment in both the horizontal and vertical dimensions. Patient age did not significantly influence alveolar bone changes.

• MeSH
• anodoncie * terapie   diagnostické zobrazování   MeSH
• čelist bezzubá MeSH
• dítě MeSH
• dospělí MeSH
• lidé MeSH
• maxila * MeSH
• mladiství MeSH
• mladý dospělý MeSH
• následné studie MeSH
• osteogeneze fyziologie   MeSH
• posun zubů * metody   MeSH
• processus alveolaris * diagnostické zobrazování   patologie   abnormality   MeSH
• rentgendiagnostika panoramatická MeSH
• resorpce alveolární kosti diagnostické zobrazování   MeSH
• řezáky * abnormality   diagnostické zobrazování   MeSH
• věkové faktory MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

During development, tooth germs undergo various morphological changes resulting from interactions between the oral epithelium and ectomesenchyme. These processes are influenced by the extracellular matrix, the composition of which, along with cell adhesion and signaling, is regulated by metalloproteinases. Notably, these include matrix metalloproteinases (MMPs), a disintegrin and metalloproteinases (ADAMs), and a disintegrin and metalloproteinases with thrombospondin motifs (ADAMTSs). Our analysis of previously published scRNAseq datasets highlight that these metalloproteinases show dynamic expression patterns during tooth development, with expression in a wide range of cell types, suggesting multiple roles in tooth morphogenesis. To investigate this, Marimastat, a broad-spectrum inhibitor of MMPs, ADAMs, and ADAMTSs, was applied to ex vivo cultures of mouse molar tooth germs. The treated samples exhibited significant changes in tooth germ size and morphology, including an overall reduction in size and an inversion of the typical bell shape. The cervical loop failed to extend, and the central area of the inner enamel epithelium protruded. Marimastat treatment also disrupted proliferation, cell polarization, and organization compared with control tooth germs. In addition, a decrease in laminin expression was observed, leading to a disruption in continuity of the basement membrane at the epithelial-mesenchymal junction. Elevated hypoxia-inducible factor 1-alpha gene (Hif-1α) expression correlated with a disruption to blood vessel development around the tooth germs. These results reveal the crucial role of metalloproteinases in tooth growth, shape, cervical loop elongation, and the regulation of blood vessel formation during prenatal tooth development.NEW & NOTEWORTHY Inhibition of metalloproteinases during tooth development had a wide-ranging impact on molar growth affecting proliferation, cell migration, and vascularization, highlighting the diverse role of these proteins in controlling development.

• Klíčová slova
• blood vessels, cervical loop, extracellular matrix, metalloproteinases, tooth germ morphogenesis,
• MeSH
• faktor 1 indukovatelný hypoxií - podjednotka alfa metabolismus   genetika   MeSH
• inhibitory matrixových metaloproteinas farmakologie   MeSH
• kyseliny hydroxamové farmakologie   MeSH
• metaloproteasy metabolismus   genetika   MeSH
• moláry embryologie   růst a vývoj   metabolismus   enzymologie   MeSH
• morfogeneze MeSH
• myši inbrední C57BL MeSH
• myši MeSH
• odontogeneze * MeSH
• proliferace buněk * MeSH
• vývojová regulace genové exprese MeSH
• zubní zárodek embryologie   metabolismus   enzymologie   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• faktor 1 indukovatelný hypoxií - podjednotka alfa MeSH
• inhibitory matrixových metaloproteinas MeSH
• kyseliny hydroxamové MeSH
• marimastat MeSH Prohlížeč
• metaloproteasy MeSH

BACKGROUND: Previous studies have claimed that pharyngeal teeth in medaka (Oryzias latipes) are induced independent of retinoic acid (RA) signaling, unlike in zebrafish (Danio rerio). In zebrafish, pharyngeal tooth formation depends on a proper physical contact between the embryonic endodermal pouch anterior to the site of tooth formation, and the adjacent ectodermal cleft, an RA-dependent process. Here, we test the hypothesis that a proper pouch-cleft contact is required for pharyngeal tooth formation in embryonic medaka, as it is in zebrafish. We used 4-[diethylamino]benzaldehyde (DEAB) to pharmacologically inhibit RA production, and thus pouch-cleft contacts, in experiments strictly controlled in time, and analyzed these using high-resolution imaging. RESULTS: Pharyngeal teeth in medaka were present only when the corresponding anterior pouch had reached the ectoderm (i.e., a physical pouch-cleft contact established), similar to the situation in zebrafish. Oral teeth were present even when the treatment started approximately 4 days before normal oral tooth appearance. CONCLUSIONS: RA dependency for pharyngeal tooth formation is not different between zebrafish and medaka. We propose that the differential response to DEAB of oral versus pharyngeal teeth in medaka could be ascribed to the distinct germ layer origin of the epithelia involved in tooth formation in these two regions.

• Klíčová slova
• dentition, ectoderm, endoderm, germ layers, pharyngeal pouches, zebrafish,
• MeSH
• dánio pruhované embryologie   MeSH
• embryo nesavčí účinky léků   MeSH
• farynx embryologie   účinky léků   MeSH
• Oryzias * embryologie   MeSH
• tretinoin * metabolismus   farmakologie   MeSH
• zuby * embryologie   účinky léků   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• tretinoin * MeSH

OBJECTIVE: We propose a method utilizing mixed reality (MR) goggles (HoloLens 2, Microsoft) to facilitate impacted canine alignment, as planning the traction direction and force delivery could benefit from 3D data visualization using mixed reality (MR). METHODS: Cone-beam CT scans featuring isometric resolution and low noise-to-signal ratio were semi-automatically segmented in Inobitec software. The exported 3D mesh (OBJ file) was then optimized for the HoloLens 2. Using the Unreal Engine environment, we developed an application for the HoloLens 2, implementing HoloLens SDK and UX Tools. Adjustable pointers were added for planning attachment placement, traction direction, and point of force application. The visualization was presented to participants of a course on impacted teeth treatment, followed by a 10-question survey addressing potential advantages (5-point scale: 1 = totally agree, 5 = totally disagree). RESULTS: Out of 38 respondents, 44.7% were orthodontists, 34.2% dentists, 15.8% dental students, and 5.3% dental technicians. Most respondents (44.7%) were between 35 and 44 years old, and only 1 (2.6%) respondent was 55-64 years old. Median answers for six questions were 'totally agree' (25th percentile 1, 75th percentile 2) and for four questions 'agree' (25th percentile 1, 75th percentile 2). No correlation was found between age, profession, and responses. CONCLUSION: Our method generated substantial interest among clinicians. The initial responses affirm the potential benefits, supporting the continued exploration of MR-based techniques for the treatment of impacted teeth. However, the recommendation for widespread use awaits validation through clinical trials.

• Klíčová slova
• AR, HoloLens 2 goggles, VR, impacted canine, mixed virtual reality,
• MeSH
• augmentovaná realita MeSH
• dospělí MeSH
• lidé MeSH
• ověření koncepční studie MeSH
• plánování péče o pacienty * MeSH
• počítačová tomografie s kuželovým svazkem * metody   MeSH
• software MeSH
• špičák diagnostické zobrazování   MeSH
• zaklíněný zub * diagnostické zobrazování   terapie   MeSH
• zobrazování trojrozměrné * metody   MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

PATIENTS: This case report presents a minimally invasive approach to replace a missing mandibular lateral incisor using a dual-injection molding technique with flowable composite resins. Integrated with a comprehensive digital workflow, this method achieves a structurally and esthetically biomimetic, bi-layered prosthetic solution. A 34-year-old woman with congenital absence of a mandibular lateral incisor was successfully rehabilitated using a direct composite resin-bonded fixed partial denture (RBFPD). DISCUSSION: Two specialized three-dimensional (3D)-printed flexible indices stabilized by a custom-designed 3D-printed rigid holder were employed to ensure the meticulous injection molding of flowable composite resins formulated to emulate the inherent chromatic gradations between dentin and enamel. The inherent flexibility of the indices, combined with the holder, facilitated accurate and seamless adaptation to the complex morphological features of the dental arch, thereby mitigating the challenges commonly associated with rigid 3D-printed resin indices. CONCLUSIONS: The bilayered direct composite RBFPD using 3D printed flexible indices prepared with a full digital workflow has several advantages over other dental prosthetic solutions, including noninvasiveness, cost-effectiveness, biomimetic esthetics, repairability, and shortened treatment times. Although the initial results are promising, further longitudinal studies with larger patient cohorts are required to confirm the long-term efficacy of this approach.

• Klíčová slova
• Bi-layered restoration, Digital workflow, Direct composite resin-bonded fixed partial denture, Injection molding technique, Missing lateral incisor,
• MeSH
• 3D tisk * MeSH
• anodoncie rehabilitace   terapie   MeSH
• biomimetika MeSH
• dospělí MeSH
• lidé MeSH
• mandibula * MeSH
• řezáky * MeSH
• složené pryskyřice * MeSH
• zubní náhrady částečné pevné lepené pryskyřicí MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH
• Názvy látek
• složené pryskyřice * MeSH

Hypoxia is relevant to several physiological and pathological processes and this also applies for the tooth. The adaptive response to lowering oxygen concentration is mediated by hypoxia-inducible factors (HIFs). Since HIFs were shown to participate in the promotion of angiogenesis, stem cell survival, odontoblast differentiation and dentin formation, they may play a beneficial role in the tooth reparative processes. Although some data were generated in vitro, little is known about the in vivo context of HIFs in tooth development. In order to contribute to this field, the mouse mandibular first molar was used as a model.The expression and in situ localisation of HIFs were examined at postnatal (P) days P0, P7, P14, using RT-PCR and immunostaining. The expression pattern of a broad spectrum of hypoxia-related genes was monitored by customised PCR Arrays. Metabolic aspects were evaluated by determination of the lactate level and mRNA expression of the mitochondrial marker Nd1.The results show constant high mRNA expression of Hif1a, increasing expression of Hif2a, and very low expression of Hif3a during early postnatal molar development. In the examined period the localisation of HIFs in the nuclei of odontoblasts and the subodontoblastic layer identified their presence during odontoblastic differentiation. Additionally, the lower lactate level and higher expression of mitochondrial Nd1 in advanced development points to decreasing glycolysis during differentiation. Postnatal nuclear localisation of HIFs indicates a hypoxic state in specific areas of dental pulp as oxygen demands depend on physiological events such as crown and root dentin mineralization.

• Klíčová slova
• Dental pulp, Development, Hypoxia-inducible factors, In vivo,
• MeSH
• faktor 1 indukovatelný hypoxií - podjednotka alfa * metabolismus   genetika   MeSH
• metabolické sítě a dráhy MeSH
• moláry * metabolismus   růst a vývoj   MeSH
• myši MeSH
• odontoblasty metabolismus   MeSH
• proteiny regulující apoptózu MeSH
• represorové proteiny MeSH
• transkripční faktory bHLH * metabolismus   genetika   MeSH
• vývojová regulace genové exprese MeSH
• zubní dřeň * metabolismus   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• endothelial PAS domain-containing protein 1 MeSH Prohlížeč
• faktor 1 indukovatelný hypoxií - podjednotka alfa * MeSH
• Hif1a protein, mouse MeSH Prohlížeč
• Hif3a protein, mouse MeSH Prohlížeč
• proteiny regulující apoptózu MeSH
• represorové proteiny MeSH
• transkripční faktory bHLH * MeSH

• MeSH
• dánio pruhované * embryologie   MeSH
• zuby přespočetné * MeSH
• zuby růst a vývoj   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• dopisy MeSH

Mammalian dentition exhibits distinct heterodonty, with more simple teeth located in the anterior area of the jaw and more complex teeth situated posteriorly. While some region-specific differences in signalling have been described previously, here we performed a comprehensive analysis of gene expression at the early stages of odontogenesis to obtain complete knowledge of the signalling pathways involved in early jaw patterning. Gene expression was analysed separately on anterior and posterior areas of the lower jaw at two early stages (E11.5 and E12.5) of odontogenesis. Gene expression profiling revealed distinct region-specific expression patterns in mouse mandibles, including several known BMP and FGF signalling members and we also identified several new molecules exhibiting significant differences in expression along the anterior-posterior axis, which potentially can play the role during incisor and molar specification. Next, we followed one of the anterior molecules, SATB2, which was expressed not only in the anterior mesenchyme where incisor germs are initiated, however, we uncovered a distinct SATB2-positive region in the mesenchyme closely surrounding molars. Satb2-deficient animals demonstrated defective incisor development confirming a crucial role of SATB2 in formation of anterior teeth. On the other hand, ectopic tooth germs were observed in the molar area indicating differential effect of Satb2-deficiency in individual jaw regions. In conclusion, our data provide a rich source of fundamental information, which can be used to determine molecular regulation driving early embryonic jaw patterning and serve for a deeper understanding of molecular signalling directed towards incisor and molar development.

• Klíčová slova
• Incisor, Lower jaw, Microarray, Molar, Mouse, Satb2,
• MeSH
• mandibula * metabolismus   embryologie   MeSH
• myši MeSH
• odontogeneze * genetika   MeSH
• řezáky metabolismus   embryologie   růst a vývoj   MeSH
• rozvržení tělního plánu genetika   MeSH
• signální transdukce MeSH
• stanovení celkové genové exprese * MeSH
• transkripční faktory * genetika   metabolismus   MeSH
• vazebné proteiny DNA v oblastech připojení k matrix * genetika   metabolismus   MeSH
• vývojová regulace genové exprese * MeSH
• zuby metabolismus   embryologie   růst a vývoj   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• SATB2 protein, mouse MeSH Prohlížeč
• transkripční faktory * MeSH
• vazebné proteiny DNA v oblastech připojení k matrix * MeSH

BACKGROUND: This 20-year retrospective study aimed to evaluate the treatment methods used in patients with impacted maxillary permanent canines and to determine the occurrence of ankylotic and resorptive processes and their association with potential risk factors. METHODS: The cohort consisted of 351 consecutive Caucasian patients (120 males and 231 females, mean age 18.4 and 19.9 years, respectively) with 420 impacted maxillary permanent canines. CT and CBCT findings were subsequently confirmed during surgery. Statistical analyses were performed by the generalized linear models, Pearson x2 and Fisher exact tests using the statistical programs R and Statistica v. 14. RESULTS: A total of 273 (65.0%) impacted canines were aligned in the dental arch by orthodontic traction after surgical exposure, this treatment was predominant in patients under 20 years of age. Surgical extraction was performed in 115 (27.2%) impacted canines and was more common in older patients. Ankylotic changes were recorded in 61 (14.5%) impacted canines. The probability of ankylosis increased with age, particularly after the patient's 20th year of life (p < 0.001). Patients were 1.2% likely to develop ankylosis at age 15 years, 4.3% at age 20 years, 14.1% at age 25 years, and 96.8% at age 45 years. Invasive cervical root resorption (ICRR) was found in 8 (1.9%) canines. In 4 canines (1.0%), root ankylosis in addition to ICRR was observed. In contrast to ankylosis, whose frequency of occurrence increased with age, the occurrence of ICRR resulting from PDL damage during surgery was more typical in younger patients. Canines in a high position above the root apices of the adjacent teeth, with a horizontal inclination of the longitudinal axis, with the crown located deep in the center of the alveolar bone and with labiopalatal position, should be considered critically impacted canines with a high risk to failure of orthodontic traction. CONCLUSION: In conclusion, the treatment of impacted canines depends mainly on the age of the patient, and the position and inclination of the longitudinal axis of the impacted tooth. To select an adequate treatment method, we recommend CBCT examination, which allows a precise analysis of the position of impacted canines.

• Klíčová slova
• Ankylosis, Autotransplantation, CBCT, Impacted canines, Invasive cervical root resorption, Orthodontic treatment, Replacement root resorption, Surgical extraction,
• MeSH
• dítě MeSH
• dospělí MeSH
• extrakce zubů MeSH
• kohortové studie MeSH
• lidé MeSH
• maxila * chirurgie   MeSH
• mladiství MeSH
• mladý dospělý MeSH
• ortodontická extruze metody   MeSH
• počítačová rentgenová tomografie MeSH
• počítačová tomografie s kuželovým svazkem * MeSH
• resorpce zubního kořene diagnostické zobrazování   etiologie   MeSH
• retrospektivní studie MeSH
• rizikové faktory MeSH
• špičák * diagnostické zobrazování   MeSH
• věkové faktory MeSH
• zaklíněný zub * chirurgie   diagnostické zobrazování   MeSH
• zubní ankylóza * diagnostické zobrazování   MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

OBJECTIVES: This study presents biological affinities between the last hunter-fisher-gatherers and first food-producing societies from the Nile Valley. We investigate odontometric and dental tissue proportion changes between these populations from the Middle Nile Valley and acknowledge the biological processes behind them. MATERIALS AND METHODS: Dental remains of 329 individuals from Nubia and Central Sudan that date from the Late Pleistocene to the mid-Holocene are studied. Using 3D imaging techniques, we investigated outer and inner metric aspects of upper central incisors, and first and second upper molars. RESULTS: Late Paleolithic and Mesolithic foragers display homogeneous crown dimensions, dental tissue proportions, and enamel thickness distribution. This contrasts with Neolithic trends for significant differences from earlier samples on inner and outer aspects. Finally, within the Neolithic sample differences are found between Nubian and Central Sudanese sites. DISCUSSION: Substantial dental variation appears to have occurred around 6000 bce in the Nile Valley, coinciding with the emergence of food-producing societies in the region. Archeological and biological records suggest little differences in dietary habits and dental health during this transition. Furthermore, the substantial variations identified here would have happened in an extremely short time, a few centuries at most. This does not support in situ diet-related adaptation. Rather, we suggest these data are consistent with some level of population discontinuity between the Mesolithic and Neolithic samples considered here. Complex settlement processes could also explain the differences between Nubia and Central Sudan, and with previous results based on nonmetric traits.

• Klíčová slova
• Neolithic transition, crown dimensions, dental tissue proportions, population discontinuity, settlement processes,
• MeSH
• dějiny starověku MeSH
• dieta dějiny   MeSH
• dospělí MeSH
• lidé MeSH
• moláry anatomie a histologie   MeSH
• paleodontologie * MeSH
• řezáky anatomie a histologie   MeSH
• zuby anatomie a histologie   chemie   MeSH
• Check Tag
• dějiny starověku MeSH
• dospělí MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• historické články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Súdán MeSH