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Dental Press Journal of Orthodontics 2024This study aimed to compare the nasopharynx and oropharynx airway dimensions of Caucasians, Blacks, Japanese, Japanese Brazilians, and Black Caucasians. (Comparative Study)
Comparative Study
OBJECTIVE
This study aimed to compare the nasopharynx and oropharynx airway dimensions of Caucasians, Blacks, Japanese, Japanese Brazilians, and Black Caucasians.
METHODS
A sample of 216 lateral radiographs of untreated young Brazilian subjects (mean age of 12.94 years; SD 0.88) were divided into five groups: Black Caucasian, Black, Caucasian, Japanese, and Japanese Brazilian. Lateral radiographs were used to measure the oropharynx (from the midpoint on the soft palate to the closest point on the anterior pharyngeal wall) and the nasopharynx (from the intersection of the posterior border of the tongue and the inferior border of the mandible to the closest point on the posterior pharyngeal wall). Analyses of variance (ANOVA) and Tukey's test were performed (p< 0.05).
RESULTS
The linear dimension of the oropharynx was similar among the different ethnic groups. Caucasian individuals presented a significantly greater linear dimension of the nasopharynx than Black Caucasian and Black individuals.
CONCLUSIONS
All the groups had similar buccopharyngeal values. However, Caucasian individuals had significantly higher values when compared to Black Caucasians and Black individuals.
Topics: Humans; Cephalometry; White People; Nasopharynx; Oropharynx; Black People; Child; Male; Female; Asian People; Mandible; Adolescent; Brazil; Tongue; Japan; Palate, Soft; Dental Occlusion; Ethnicity
PubMed: 38775599
DOI: 10.1590/2177-6709.29.2.e2423206.oar -
Clinical, Cosmetic and Investigational... 2024The need to increase the Vertical Dimension of Occlusion (VDO) to restore lost dental function or optimise specific dental treatments is a common occurrence in daily... (Review)
Review
The need to increase the Vertical Dimension of Occlusion (VDO) to restore lost dental function or optimise specific dental treatments is a common occurrence in daily dental practice. The common belief that the Vertical Dimension at Rest (VDR) is fixed hinders the development of restorations with a VDO that encroaches on or surpasses the interocclusal rest space (IRS), thereby preventing potential tissue damage to the masticatory apparatus. Recent studies have shown that the mandible rest position falls within a range termed as the "comfort zone". The range of this zone may vary from one person to another and within the same person over time due to factors such as age or health status. In this review, we have concluded that a permanent increase in the VDO, once indicated, is a safe procedure for dentulous patients. However, it is important to minimise the extent of the increase to simplify the prosthodontics treatment process. An inter-incisal increase exceeding 5 mm is seldom needed. Moreover, it is important to consider the functional, aesthetic, and biological elements associated with VDO. The biological and functional environment closely related to the VDO had great adaptive capacities, which have for a historically been underestimated. Patient adaptation has been observed in dentate patients, edentulous patients, and even cases involving implant-supported prostheses. Muscle relaxation and changes in muscle length are likely the primary adaptation mechanisms, rather than the restoration of the original VDO through dentoalveolar maturation. Intervention with a fixed restoration is more predictable and results in a higher and more rapid level of adaptation. Finally, the increase should include the entire arch to prevent relapse of the VDO to its previous value, and changes in VDO should be assessed by utilising temporary diagnostic restorations for a period before implementing definitive prostheses, in order to evaluate the adaptive muscle response.
PubMed: 38770218
DOI: 10.2147/CCIDE.S453704 -
European Journal of Dentistry May 2024Conventional glass ionomer cements (GICs) have been considered the most prevalent restorative material however; the reduced mechanical qualities and decreased wear...
OBJECTIVES
Conventional glass ionomer cements (GICs) have been considered the most prevalent restorative material however; the reduced mechanical qualities and decreased wear resistance have been the main challenges facing their wide clinical application. This study was designed to assess the mechanical properties of fluorinated graphene (FG) oxide-modified conventional GIC.
MATERIALS AND METHODS
Composites of FG/GIC samples were prepared using (Medifil from PROMEDICA, Germany, shade A3) at different concentrations (0wt%) control group and (1wt%, 2wt% and 3wt% FG) groups using cylindrical molds (3mm × 6mm). FG was prepared using hydrothermal technique and characterized using XPERT-PRO Powder Diffractometer system for X-ray diffraction analysis and JEOL JEM-2100 high resolution transmission electron microscope. Vickers' hardness and wear resistance of GI samples were measured. Mechanical abrasion was performed via three-body tooth brushing wear test using ROBOTA chewing simulator coupled with a thermocycling protocol (Model ACH-09075DC-T, AD-Tech Technology Co., Ltd., Leinfelden-Echterdingen, Germany).
STATISTICAL ANALYSIS
Comparisons between groups with respect to normally distributed numeric variables were performed using one-way analysis of variance test followed by posthoc test. While paired -test was utilized for comparing data within the same group.
RESULTS
The surface roughness values of GICs (1wt% FG) and (2wt% FG) composites were significantly lower than those of the control and 3wt%FG groups. Vickers' hardness numbers were significantly higher in FG/GICs composites than in the control group (≤0.05).
CONCLUSION
GIC/FG combinations have sufficient strength to resist the occlusion stresses with improved hardness as compared with conventional GIC. GIC/FG appeared to be a promising restorative material.
PubMed: 38759994
DOI: 10.1055/s-0044-1785188 -
Cureus May 2024Accurate occlusal vertical dimension (OVD) establishment is an essential component of prosthodontic treatment. No accurate approach exists to determine the appropriate...
OBJECTIVES
Accurate occlusal vertical dimension (OVD) establishment is an essential component of prosthodontic treatment. No accurate approach exists to determine the appropriate OVD for patients without posterior teeth. This study aimed to correlate the accuracy of the nose-to-chin distance with various facial measurements and thumb length in dentulous and edentulous Saudi patients.
MATERIALS AND METHODS
The participants comprised 100 fully dentulous Saudi male dental students aged 20-30 years (group 1) and 20 completely edentulous patients aged 60-70 years (group 2). We evaluated the correlations between the OVD (nose-to-chin distance) and the distance from the pupil to the corner of the mouth, the vertical length at midline of the nose (from subnasion to glabella), the distance from the outer canthus of one eye to the inner canthus of the other, twice the distance between the inner canthi, and the distance from the thumb tip to the index fingertip.
STATISTICAL ANALYSIS
Spearman's correlation and regression analysis were performed to analyze and assess the correlations between the clinically measured nose-to-chin distance and other parameters, with significance set at 0.05.
RESULTS
In edentulous patients, the results showed a significant, strong, positive correlation between the nose-to-chin distance and the distance between the pupil and the mouth corner. In dentate subjects, a significant, strong, positive association was found between the nose-to-chin distance and the distance from the outer canthus of one eye to the inner canthus of the other. The linear regression analysis revealed that the distance between the pupil and the mouth corner in edentulous patients significantly predicted the OVD.
CONCLUSIONS
In both groups, the distance from the outer canthus of one eye to the inner canthus of the other and the distance from the pupil to the mouth corner were reliable and accurate for OVD measurements. These could be considered appropriate methods for OVD determination during full-mouth rehabilitation.
PubMed: 38756708
DOI: 10.7759/cureus.60443 -
Tissue Engineering. Part A Jun 2024Ischemic stroke is a devastating medical condition with poor prognosis due to the lack of effective treatment modalities. Transplantation of human neural stem cells or...
Ischemic stroke is a devastating medical condition with poor prognosis due to the lack of effective treatment modalities. Transplantation of human neural stem cells or primary neural cells is a promising treatment approach, but this is hindered by limited suitable cell sources and low expansion capacity. This study aimed (1) use small molecules (SM) to reprogram gingival mesenchymal stem cells (GMSCs) commitment to the neural lineage cells , and (2) use hyaluronic acid (HA) hydrogel scaffolds seeded with GMSCs-derived neural lineage cells to treat ischemic stroke . Neural induction was carried out with a SM cocktail-based one-step culture protocol over a period of 24 h. The induced cells were analyzed for expression of neural markers with immunocytochemistry and quantitative real-time polymerase chain reaction (qRT-PCR). The Sprague-Dawley (SD) rats ( = 100) were subjected to the middle cerebral artery occlusion (MCAO) reperfusion ischemic stroke model. Then, after 8 days post-MCAO, the modeled rats were randomly assigned to six study groups ( = 12 per group): (1) GMSCs, (2) GMSCs-derived neural lineage cells, (3) HA and GMSCs-derived neural lineage cells, (4) HA, (5) PBS, and (6) sham transplantation control, and received their respective transplantation. Evaluation of post-stroke recovery were performed by behavioral tests and histological assessments. The morphologically altered nature of neural lineages has been observed of the GMSCs treated with SMs compared to the untreated controls. As shown by the qRT-PCR and immunocytochemistry, SMs further significantly enhanced the expression level of neural markers of GMSCs as compared with the untreated controls (all < 0.05). Intracerebral injection of self-assembling HA hydrogel carrying GMSCs-derived neural lineage cells promoted the recovery of neural function and reduced ischemic damage in rats with ischemic stroke, as demonstrated by histological examination and behavioral assessments (all < 0.05). In conclusion, the SM cocktail significantly enhanced the differentiation of GMSCs into neural lineage cells. The HA hydrogel was found to facilitate the proliferation and differentiation of GMSCs-derived neural lineage cells. Furthermore, HA hydrogel seeded with GMSCs-derived neural lineage cells could promote tissue repair and functional recovery in rats with ischemic stroke and may be a promising alternative treatment modality for stroke.
PubMed: 38756085
DOI: 10.1089/ten.TEA.2023.0330 -
International Journal of Biological... Jun 2024The objective of this study was to evaluate the synergistic effect of eggshell-derived nanohydroxyapatite (EnHA) and carboxymethyl chitosan (CMC) in remineralizing...
The objective of this study was to evaluate the synergistic effect of eggshell-derived nanohydroxyapatite (EnHA) and carboxymethyl chitosan (CMC) in remineralizing artificially induced dentinal lesions. EnHA and CMC were synthesized using simple chemical processes and characterized using FTIR, XRD, HRSEM-EDX, TEM, DLS and TGA/DTA analyses. A total of 64 pre-demineralized coronal dentin specimens were randomly subjected to following treatments (n = 16):artificial saliva (AS), EnHA, CMC, and EnHA-CMC, followed by pH cycling for 7 days. HRSEM-EDX, Vickers-indenter, and micro-Raman analyses were used to assess surface-topography, microhardness, and chemical analysis, respectively. All tested materials demonstrated non-cytotoxicity when assessed on hDPSCs using MTT assay. FTIR, XRD and thermal analyses confirmed the characteristics of both EnHA and CMC. EnHA showed irregular rod-shaped nanoparticles (30-70 nm) with the presence of Ca,P,Na, and Mg ions. Dentin treated with EnHA-CMC exhibited complete tubular occlusion and highest microhardness whereas the AS group revealed the least mineral deposits (p < 0.05). No significant differences were observed between EnHA and CMC groups (p > 0.05). In addition, molecular conformation analysis revealed peak intensities in collagen's polypeptide chains in dentin treated with CMC and EnHA-CMC, whereas other groups showed poor collagen stability. The results highlighted that EnHA-CMC aided in rapid and effective biomineralization, suggesting its potential as a therapeutic solution for treating dentin caries.
Topics: Chitosan; Durapatite; Dentin; Egg Shell; Animals; Humans; Tooth Remineralization; Nanoparticles; Biomimetic Materials; Hydrogen-Ion Concentration
PubMed: 38754678
DOI: 10.1016/j.ijbiomac.2024.132359 -
BMC Oral Health May 2024Prefabricated myofunctional appliance can guide tooth eruption, improve dentition alignment, correct myofunctional disorders and harmful oral habits. However, its...
BACKGROUND
Prefabricated myofunctional appliance can guide tooth eruption, improve dentition alignment, correct myofunctional disorders and harmful oral habits. However, its application to skeletal discrepancy may result in unsatisfactory tooth inclination. This study aimed to construct a novel appliance with overjet design to avoid this side effect and investigated its shape and mechanical changes under occlusion using three-dimensional finite element method.
METHODS
We established three samples of prefabricated myofunctional appliances. The first one was edge to edge without overjet, and the outer shield of both jaws were flattened. The second one was 3 mm overjet with stepped the outer shield. The last one was 3 mm overjet, and the outer shield of both jaws were flatted, which meant the front wall of lower jaw was strengthened with bumper, termed as lower bumper. A complete dentition model was applied to the study. 150 N occlusal force was applied to each type of appliance and the deformation displacement and the changes in stress was recorded.
RESULTS
The deformation was significant in the incisors regions, especially in the vertical and lateral dimensions. The maximum displacements of 3 mm overjet with step shield group were 7.08 mm (vertical), 3.99 mm (lateral), and 2.90 mm (sagittal), while it decreased to 3.92 mm(vertical), 1.94 mm (lateral), and 1.55 mm (sagittal) in overjet with bumper group. Moreover, the upper molar regions exhibited higher vertical and sagittal displacement in 3 mm overjet with step shield group, which were 3.03 mm (vertical) and 1.99 mm (sagittal), and the bumper design could decrease the maximum displacement to 1.72 mm (vertical) and 0.72 mm (sagittal). In addition, the Von Mises stress of appliances was analyzed, and results indicated that 3 mm overjet with step shield generated higher stress than other groups, with the maximum Von Mises stress was 0.9387 MP, which were 0.5858 and 0.5657 MP in edge to edge group and 3 mm overjet with lower bumper group, respectively.
CONCLUSION
The prefabricated myofunctional appliances may cause deformation during occlusion. Compared to step shield group, the application of lower bumper exhibited better resistance to occlusal force.
Topics: Finite Element Analysis; Humans; Orthodontic Appliance Design; Myofunctional Therapy; Bite Force; Imaging, Three-Dimensional; Overbite; Stress, Mechanical; Mandible; Incisor; Biomechanical Phenomena
PubMed: 38745284
DOI: 10.1186/s12903-024-04325-3 -
Head & Face Medicine May 2024In this study, we sought to quantify the influence of vertical control assisted by a temporary anchorage device (TAD) on orthodontic treatment efficacy for skeletal...
BACKGROUND
In this study, we sought to quantify the influence of vertical control assisted by a temporary anchorage device (TAD) on orthodontic treatment efficacy for skeletal class II patients with a hyperdivergent facial type and probe into the critical factors of profile improvement.
METHODS
A total of 36 adult patients with skeletal class II and a hyperdivergent facial type were included in this retrospective case-control study. To exclude the effect of sagittal anchorage reinforcement, the patients were divided into two groups: a maxillary maximum anchorage (MMA) group (N = 17), in which TADs were only used to help with anterior tooth retraction, and the MMA with vertical control (MMA + VC) group (N = 19), for which TADs were also used to intrude the maxillary molars and incisors. The treatment outcome was evaluated using dental, skeletal, and soft-tissue-related parameters via a cephalometric analysis and cast superimposition.
RESULTS
A significant decrease in ANB (P < 0.05 for both groups), the retraction and uprighting of the maxillary and mandibular incisors, and the retraction of protruded upper and lower lips were observed in both groups. Moreover, a significant intrusion of the maxillary molars was observed via the cephalometric analysis (- 1.56 ± 1.52 mm, P < 0.05) and cast superimposition (- 2.25 ± 1.03 mm, P < 0.05) of the MMA + VC group but not the MMA group, which resulted in a remarkable decrease in the mandibular plane angle (- 1.82 ± 1.38°, P < 0.05). The Z angle (15.25 ± 5.30°, P < 0.05) and Chin thickness (- 0.97 ± 0.45°, P < 0.05) also improved dramatically in the MMA + VC group, indicating a better profile and a relaxed mentalis. Multivariate regression showed that the improvement in the soft tissue was closely related to the counterclockwise rotation of the mandible plane (P < 0.05).
CONCLUSIONS
TAD-assisted vertical control can achieve intrusion of approximately 2 mm for the upper first molars and induce mandibular counterclockwise rotation of approximately 1.8°. Moreover, it is especially important for patients without sufficient retraction of the upper incisors or a satisfactory chin shape.
Topics: Humans; Malocclusion, Angle Class II; Female; Male; Retrospective Studies; Cephalometry; Adult; Case-Control Studies; Young Adult; Treatment Outcome; Orthodontic Anchorage Procedures; Orthodontics, Corrective; Tooth Movement Techniques; Vertical Dimension; Adolescent
PubMed: 38745246
DOI: 10.1186/s13005-024-00432-2 -
Stomatologiia 2024Prevention of the development of pronounced skeletal abnormalities in patients with mesial occlusion.
OBJECTIVE
Prevention of the development of pronounced skeletal abnormalities in patients with mesial occlusion.
MATERIALS AND METHODS
Biometric analysis of control and diagnostic models of dentition was performed in 60 patients with dental anomalies before and after treatment in 3 mutually perpendicular planes to identify violations in the formation of dental arches by sagittal and transversal dimensions, and alveolar processes - by vertical dimensions (methods of A. Pont, G. Korkhaus). Measurements of 23 parameters of TRG and sections of CBCT were carried out using the modified Nad-Ars technique with analysis of skeletal parameters before and after treatment. Treatment was carried out using dilators for the upper jaw in combination with a facial mask and further dynamic observation using active retention devices.
RESULTS
The results of treatment showed an increase in the length of the anterior segment of the upper dental arch by 2.8±0.55 mm (<0.05 mm); expansion in the area of temporary molars by 2.85±0.65 mm (<0.05); in the area of permanent molars by 2.75±0.55 mm (<0.05); in the area of the apical basis of HF by 3.82±0.45 mm (<0.05). The length of the lower dental arch in the anterior segment has not changed. Analysis of TRG parameters showed a significant increase in the values of
dental alveolar arches, the inclination of the occlusal plane, and the improvement of the bite were achieved. CONCLUSION
Early orthodontic treatment made it possible to create favorable conditions and prepare the patient's occlusion for a change of teeth, to form dental alveolar arches, to reduce the degree of complexity of therapeutic measures that may be needed after the completion of skeletal growth.
Topics: Humans; Child; Male; Female; Dental Arch; Malocclusion; Palatal Expansion Technique; Bone Screws; Dental Occlusion; Orthodontic Anchorage Procedures; Adolescent; Orthodontic Appliances, Fixed
PubMed: 38741537
DOI: 10.17116/stomat202410302161 -
Stomatologiia 2024Increasing the effectiveness of treatment of chronic generalized periodontitis using PDT based on clinical and functional substantiation of the effects of a...
OBJECTIVE
Increasing the effectiveness of treatment of chronic generalized periodontitis using PDT based on clinical and functional substantiation of the effects of a photosensitizer.
MATERIALS AND METHODS
A clinical and functional study and treatment of moderate chronic generalized periodontitis was carried out in 62 people (26 men and 36 women) aged from 35 to 55 years without a somatic model with an orthognathic occlusion diagnosed according to ICD-10 - K05.3. Of these, 2 groups were divided depending on the type of treatment: Group 1 (main) - patients with moderate chronic generalized periodontitis - 32 people. (17 men and 15 women, average age of the group - 43.2±2.2 years); Group 2 (control) - patients with moderate chronic generalized periodontitis - 30 people. (14 men and 16 women, average age of the group - 44.0±3.3 years). Complex treatment consisted of sanitation of the mouth, removal of dental plaque and curettage of periodontal pockets in group 1, followed by PDT with Revixan gel using a special wired aligner REVIXAN DENTAL LED (16 r). The clinical condition of the periodontium was assessed using the Greene Vermillion Hygienic Index (OHI-S), the Mühlleman Bleeding Index (SBI) modified by Cowell, and the periodontal index PI. To study the state of microcirculation in the gum tissue, the laser Doppler flowmetry (LDF) method was used using the LAKK-M device (NPP «Lazma», Russia). The state of microcirculation was assessed by the microcirculation index (M), which characterizes the level of tissue blood flow; parameter - «σ», which determines the fluctuation of the erythrocyte flow. According to Wavelet analysis of LDF-grams, the shunt index (SH) of blood flow was determined. In the «LDF + spectrometry» mode, oxygenation in periodontal tissues was studied using optical tissue oximetry (OTO), based on the results of which the perfusion saturation index (Sm) and the specific oxygen consumption index (U, %) were determined.
RESULTS
According to LDF data, after PDT (group 1), normalization of clinical indices and the level of microcirculation in periodontal tissues was established, which was accompanied by an increase in the level of blood flow (M) and its activity (σ), which persisted after 3 and 6 months. after PDT. The perfusion saturation index (Sm) and specific oxygen consumption (U) increased more significantly after PDT, which persisted after 3 and 6 months. In the control group, the dynamics of indicators was less pronounced.
CONCLUSION
The use of PDT with Revixan gel normalizes the clinical condition of the periodontium, indicators of microhemodynamics and oxygen metabolism.
Topics: Humans; Female; Male; Adult; Microcirculation; Middle Aged; Chronic Periodontitis; Photochemotherapy; Photosensitizing Agents; Periodontium; Oxygen
PubMed: 38741530
DOI: 10.17116/stomat202410302118