BACKGROUND: Orofacial clefts are common congenital malformations, affecting both facial aesthetics and function. Intubation in newborns with cleft lip and palate is challenging and carries a high risk of oral tissue damage. This study investigates the use of a customized protective palatal obturator (CPPO) to improve intubation safety and reduce tissue injury during cleft lip surgery. METHODS: A single-center, randomized neonatal sub-study was conducted, including 55 newborns who underwent cleft lip surgery. Patients were randomized into an intervention group (CPPO use) and a control group (standard intubation without CPPO). The primary aim was to evaluate the degree of oral tissue injury during intubation, its severity, and location, in both groups, secondary aims included laryngoscopy image during intubation (modified Cormack-Lehane scoring system), intubation time, and attempts, number of intubations attempts and anesthesiologic complication during intubation. This study was registered on www.clinicaltrials.gov (ClinicalTrials.gov Identifier: NCT04422847 and NCT04422964). RESULTS: No tissue damage occurred in the CPPO group, while the control group had a 21.4% incidence of tissue injury (p = .023). Secondary outcomes showed no statistically significant differences between groups for intubation time or the number of intubation attempts. Difficult intubation was less frequent in the CPPO group (40.7%) compared to the control group (50%), though this difference was not statistically significant. CONCLUSION: The CPPO significantly reduces the risk of tissue damage during intubation in newborns undergoing cleft lip surgery, without increasing intubation time or attempts. It is particularly beneficial for severe clefts, and its use may facilitate safer airway management in these high-risk patients.
Customized protective palatal obturators enhance intubation safety in newborns with cleft lip, alveolus and palate.The customized protective palatal obturator is especially advantageous for patients with more severe clefts, offering better protection against tissue damage during intubation.The customized protective palatal obturator does not prolong intubation time or increase the number of intubation attempts, making it an effective tool for better airway management without added difficulty or delay.
- Klíčová slova
- 3D printing, Cleft lip, anesthesia management, intubation, newborns, patient specific approach, protective obturator, tissue damage,
- MeSH
- intratracheální intubace * přístrojové vybavení škodlivé účinky metody MeSH
- laryngoskopie metody MeSH
- lidé MeSH
- novorozenec MeSH
- obturátory patra * MeSH
- rozštěp patra * chirurgie MeSH
- rozštěp rtu * chirurgie MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- novorozenec MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- randomizované kontrolované studie MeSH
STATEMENT OF PROBLEM: Intraoral scanning is currently becoming the standard method for imaging the maxilla in patients with cleft lip and palate. However, the reliability of intraoral scans compared with traditional conventional impression methods has not yet been sufficiently described and examined in detail in newborns with severe types of cleft lip and palate. PURPOSE: The purpose of this clinical study was to assess the reliability and agreement between intraoral scanning and traditional impression methods for maxillary measurements in newborns with unilateral and bilateral cleft lip and palate (U/BCLP). A secondary aim was to evaluate the consistency of maxillary measurements obtained with and without general anesthesia. MATERIAL AND METHODS: Six newborns with cleft lip and palate underwent 4 maxillary impression methods (silicone impression and 3-dimensional (3D) scan, with and without anesthesia). Intra- and inter-observer reliability was assessed by 3 clinicians using intraclass correlation coefficient, median absolute deviation, and median relative deviation (α=.05). RESULTS: The intraclass correlation coefficient values for both inter-observer and intra-observer reliability indicated excellent agreement (ICC>.90, P<.05) for maxillary dimension measurements. Acceptable variability was observed because of differences in reference point identification by clinicians and across data collection methods. CONCLUSIONS: When assessing the maxilla in U/BCLP patients, both intraoral scanner and traditional impression techniques showed excellent reliability and agreement in measurements, whether performed while the newborns were awake or under general anesthesia.
- MeSH
- lidé MeSH
- materiály pro zubní otisky * MeSH
- maxila diagnostické zobrazování MeSH
- novorozenec MeSH
- reprodukovatelnost výsledků MeSH
- rozštěp patra * diagnostické zobrazování MeSH
- rozštěp rtu * diagnostické zobrazování MeSH
- silikony * MeSH
- zobrazování trojrozměrné * metody MeSH
- zubní technika otisková * MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- novorozenec MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- srovnávací studie MeSH
- Názvy látek
- materiály pro zubní otisky * MeSH
- silikony * MeSH
OBJECTIVES: This study evaluated maxillary growth and dental arch relationships at 5 and 10 years of age in patients with unilateral cleft lip and palate (UCLP) who underwent early cleft lip and palate surgery. METHODS: 28 patients with UCLP who underwent cleft lip surgery in neonatal age and cleft palate surgery at average age of 7 months without orthodontic treatment (intervention group) were measured for intercanine and intermolar distances and for dental arch length. These measurements were compared with those of 30 healthy participants in a control group. Dental arch relationships in the intervention group were evaluated by 5-YO index at 5 years and the GOSLON Yardstick score at 10 years of patients' age. RESULTS: Patients in the intervention group had significantly shorter mean intercanine distance and arch length than control patients at both 5 and 10 years of age (p<.001 for all). There were no significant differences in intermolar distance at both 5 (p = .945) and 10 years (p = .105) of patients' age. The average 5YO index increased from 2.46 to an average GOSLON 10-year score of 2.89 in intervention group. CONCLUSION: Intercanine distance and dental arch length of patients with UCLP are significantly reduced at 5 and 10 years after early cleft lip and palate surgeries compared to the healthy population. Dental arch relationships at 5 and 10 years of patients with UCLP show comparable outcomes to those reported by other cleft centers. CLINICAL SIGNIFICANCE: This study evaluates maxillary growth in UCLP patients 5 and 10 years of age who underwent early primary lip and palate surgery.
- Klíčová slova
- 5YO index, Cleft lip and palate, Dental arch relationship, GOSLON, Neonatal cleft lip surgery,
- MeSH
- dítě MeSH
- lidé MeSH
- maxila * chirurgie růst a vývoj MeSH
- maxilofaciální vývoj MeSH
- předškolní dítě MeSH
- průřezové studie MeSH
- rozštěp patra * chirurgie MeSH
- rozštěp rtu * chirurgie MeSH
- studie případů a kontrol MeSH
- zubní oblouk * růst a vývoj patologie chirurgie MeSH
- Check Tag
- dítě MeSH
- lidé MeSH
- mužské pohlaví MeSH
- předškolní dítě MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
Cleft lip and cleft palate are among the most common congenital defects of the head. The treatment of clefts is centralized, multidisciplinary, and involves a plastic surgeon, orthodontist, anesthesiologist, clinical speech therapist, and other specialists. While the incidence of cleft lip and cleft palate remains approximately unchanged, the approach to their treatment is evolving. Modern treatment methods increasingly include 3D printing and the associated therapeutic and educational possibilities.
- Klíčová slova
- cleft lip and palate, anesthesia in children, 3D printing, 3D models,
- MeSH
- lidé MeSH
- rozštěp patra * terapie chirurgie MeSH
- rozštěp rtu * terapie chirurgie MeSH
- týmová péče o pacienty MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
STATEMENT OF PROBLEM: Accurate implant placement is essential for the success of dental implants. This placement influences osseointegration and occlusal forces. The freehand technique, despite its cost-effectiveness and time efficiency, may result in significant angular deviations compared with guided implantation, but the effect of angular deviations on the stress-strain state of peri-implant bone is unclear. PURPOSE: The purpose of this finite element analysis (FEA) study was to examine the effects of angular deviations on stress-strain states in peri-implant bone. MATERIAL AND METHODS: Computational modeling was used to investigate 4 different configurations of dental implant positions, each with 3 angles of insertion. The model was developed using computed tomography images, and typical mastication forces were considered. Strains were analyzed using the mechanostat hypothesis. RESULTS: The location of the implant had a significant impact on bone strain intensity. An angular deviation of ±5 degrees from the planned inclination did not significantly affect cancellous bone strains, which primarily support the implant. However, it had a substantial effect on strains in the cortical bone near the implant. Such deviations also significantly influenced implant stresses, especially when the support from the cortical bone was uneven or poorly localized. CONCLUSIONS: In extreme situations, angular deviations can lead to overstraining the cortical bone, risking implant failure from unfavorable interaction with the implant. Accurate implant placement is essential to mitigate these risks.
Patient-specific approach is gaining a wide popularity in computational simulations of biomechanical systems. Simulations (most often based on the finite element method) are to date routinely created using data from imaging devices such as computed tomography which makes the models seemingly very complex and sophisticated. However, using a computed tomography in finite element calculations does not necessarily enhance the quality or even credibility of the models as these depend on the quality of the input images. Low-resolution (medical-)CT datasets do not always offer detailed representation of trabecular bone in FE models and thus might lead to incorrect calculation of mechanical response to external loading. The effect of image resolution on mechanical simulations of bone-implant interaction has not been thoroughly studied yet. In this study, the effect of image resolution on the modeling procedure and resulting mechanical strains in bone was analyzed on the example of cranial implant. For this purpose, several finite element models of bone interacting with fixation-screws were generated using seven computed tomography datasets of a bone specimen but with different image resolutions (ranging from micro-CT resolution of 25 μm to medical-CT resolution of 1250 μm). The comparative analysis revealed that FE models created from images of low resolution (obtained from medical computed tomography) can produce biased results. There are two main reasons: 1. Medical computed tomography images do not allow generating models with complex trabecular architecture which leads to substituting of the intertrabecular pores with a fictitious mass; 2. Image gray value distribution can be distorted resulting in incorrect mechanical properties of the bone and thus in unrealistic or even completely fictitious mechanical strains. The biased results of calculated mechanical strains can lead to incorrect conclusion, especially when bone-implant interaction is investigated. The image resolution was observed not to significantly affect stresses in the fixation screw itself; however, selection of bone material representation might result in significantly different stresses in the screw.
- Klíčová slova
- Bone tissue, Computational modeling, Computed tomography, Finite element method, Image resolution, Mechanical strain,
- MeSH
- analýza metodou konečných prvků MeSH
- biomechanika MeSH
- kosti a kostní tkáň * MeSH
- kostní šrouby * MeSH
- lidé MeSH
- mechanický stres MeSH
- rentgenová mikrotomografie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The purpose of this study was to investigate the effect of load-induced local mechanical strain on bone cell activity of peri-implant bone in mice. Titanium implants were placed in the maxillae of 13-week-old male C57BL/6J mice and subjected to intermittent 0.15 N, 0.3 N, or 0.6 N loads for 30 min/day for 6 days. The animals were sacrificed 2 days after the final loading. Unloaded mice were used as controls. An animal-specific three-dimensional finite element model was constructed based on morphological data retrieved from in vivo microfocus computed tomography for each mouse to calculate the mechanical strain distribution. Strain distribution images were overlaid on corresponding histological images of the same site in the same animal. The buccal cervical region of the peri-implant bone was predetermined as the region of interest (ROI). Each ROI was divided by four strain intensity levels: 0-20 με, 20-60 με, 60-100 με, and ≥100 με, and the bone histomorphometric parameters were analyzed by the total area of each strain range for all loaded samples. The distance between the calcified front and calcein labeling as a parameter representing the mineral apposition rate was significantly greater in the areas with strain intensity ≥100 με than in the area with strain intensity <100 με, suggesting that the bone formation activity of osteoblasts was locally enhanced by a higher mechanical strain. However, the shrunken osteocytes and the empty osteocyte lacunae were significantly lower in the highest strain area, suggesting that osteoclastogenesis was more retarded in higher strain areas than in lower strain areas. The histomorphometric parameters were not affected geometrically in the unloaded animals, suggesting that the load-induced mechanical strain caused differences in the histomorphometric parameters. Our findings support the hypothesis that bone cell activity related to bone resorption and formation is local strain-dependent on implant loading.
- Klíčová slova
- Bone remodeling, Dental implants, Histomorphometry, Mechanotransduction, Osteoblasts, Stress analysis,
- MeSH
- analýza metodou konečných prvků MeSH
- mechanický stres MeSH
- myši inbrední C57BL MeSH
- myši MeSH
- osteocyty MeSH
- resorpce kosti * MeSH
- zubní implantáty * MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- zubní implantáty * MeSH
Trees are known to emit methane (CH4 ) and nitrous oxide (N2 O), with tropical wetland trees being considerable CH4 sources. Little is known about CH4 and especially N2 O exchange of trees growing in tropical rain forests under nonflooded conditions. We determined CH4 and N2 O exchange of stems of six dominant tree species, cryptogamic stem covers, soils and volcanic surfaces at the start of the rainy season in a 400-yr-old tropical lowland rain forest situated on a basaltic lava flow (Réunion Island). We aimed to understand the unknown role in greenhouse gas fluxes of these atypical tropical rain forests on basaltic lava flows. The stems studied were net sinks for atmospheric CH4 and N2 O, as were cryptogams, which seemed to be co-responsible for the stem uptake. In contrast with more commonly studied rain forests, the soil and previously unexplored volcanic surfaces consumed CH4 . Their N2 O fluxes were negligible. Greenhouse gas uptake potential by trees and cryptogams constitutes a novel and unique finding, thus showing that plants can serve not only as emitters, but also as consumers of CH4 and N2 O. The volcanic tropical lowland rain forest appears to be an important CH4 sink, as well as a possible N2 O sink.
- Klíčová slova
- basaltic lava flows, cryptogams, methane flux, nitrous oxide flux, soil, tree stem, tropical lowland rain forest, uptake,
- MeSH
- deštný prales MeSH
- lesy MeSH
- methan MeSH
- oxid dusný * MeSH
- oxid uhličitý MeSH
- půda MeSH
- stromy * MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Réunion MeSH
- Názvy látek
- methan MeSH
- oxid dusný * MeSH
- oxid uhličitý MeSH
- půda MeSH
This study investigated the effect of implant thickness and material on deformation and stress distribution within different components of cranial implant assemblies. Using the finite element method, two cranial implants, differing in size and shape, and thicknesses (1, 2, 3 and 4 mm, respectively), were simulated under three loading scenarios. The implant assembly model included the detailed geometries of the mini-plates and micro-screws and was simulated using a sub-modeling approach. Statistical assessments based on the Design of Experiment methodology and on multiple regression analysis revealed that peak stresses in the components are influenced primarily by implant thickness, while the effect of implant material is secondary. On the contrary, the implant deflection is influenced predominantly by implant material followed by implant thickness. The highest values of deformation under a 50 N load were observed in the thinnest (1 mm) Polymethyl Methacrylate implant (Small defect: 0.296 mm; Large defect: 0.390 mm). The thinnest Polymethyl Methacrylate and Polyether Ether Ketone implants also generated stresses in the implants that can potentially breach the materials' yield limit. In terms of stress distribution, the change of implant thickness had a more significant impact on the implant performance than the change of Young's modulus of the implant material. The results indicated that the stresses are concentrated in the locations of fixation; therefore, the detailed models of mini-plates and micro-screws implemented in the finite element simulation provided a better insight into the mechanical performance of the implant-skull system.
- Klíčová slova
- 3D printing, Cranioplasty, Finite element method, Mechanical properties, Skull implant,
- MeSH
- analýza metodou konečných prvků * MeSH
- experimentální implantáty * MeSH
- lebka * MeSH
- lidé MeSH
- mechanický stres * MeSH
- počítačová simulace * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Osseointegration is paramount for the longevity of dental implants and is significantly influenced by biomechanical stimuli. The aim of the present study was to assess the micro-strain and displacement induced by loaded dental implants at different stages of osseointegration using finite element analysis (FEA). Computational models of two mandible segments with different trabecular densities were constructed using microCT data. Three different implant loading directions and two osseointegration stages were considered in the stress-strain analysis of the bone-implant assembly. The bony segments were analyzed using two approaches. The first approach was based on Mechanostat strain intervals and the second approach was based on tensile/compression yield strains. The results of this study revealed that bone surrounding dental implants is critically strained in cases when only a partial osseointegration is present and when an implant is loaded by buccolingual forces. In such cases, implants also encounter high stresses. Displacements of partially-osseointegrated implant are significantly larger than those of fully-osseointegrated implants. It can be concluded that the partial osseointegration is a potential risk in terms of implant longevity.
- Klíčová slova
- Dental implants, Micro finite element analysis, Osseointegration, Strain intensity, Stress intensity,
- MeSH
- analýza metodou konečných prvků MeSH
- analýza zatížení zubů metody MeSH
- biologické modely * MeSH
- biomechanika MeSH
- lidé MeSH
- mandibula fyziologie MeSH
- mechanický stres MeSH
- osteointegrace fyziologie MeSH
- počítačové zpracování signálu MeSH
- rentgenová mikrotomografie MeSH
- zubní implantáty * MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- zubní implantáty * MeSH
