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Science Advances Jun 2024Rotator cuff repair surgeries fail frequently, with 20 to 94% of the 600,000 repairs performed annually in the United States resulting in retearing of the rotator cuff....
Rotator cuff repair surgeries fail frequently, with 20 to 94% of the 600,000 repairs performed annually in the United States resulting in retearing of the rotator cuff. The most common cause of failure is sutures tearing through tendons at grasping points. To address this issue, we drew inspiration from the specialized teeth of snakes of the Pythonoidea superfamily, which grasp soft tissues without tearing. To apply this nondamaging gripping approach to the surgical repair of tendon, we developed and optimized a python tooth-inspired device as an adjunct to current rotator cuff suture repair and found that it nearly doubled repair strength. Integrated simulations, 3D printing, and ex vivo experiments revealed a relationship between tooth shape and grasping mechanics, enabling optimization of the clinically relevant device that substantially enhances rotator cuff repair by distributing stresses over the attachment footprint. This approach suggests an alternative to traditional suturing paradigms and may reduce the risk of tendon retearing after rotator cuff repair.
Topics: Animals; Rotator Cuff; Boidae; Rotator Cuff Injuries; Tooth; Suture Techniques; Biomechanical Phenomena; Humans; Printing, Three-Dimensional
PubMed: 38941456
DOI: 10.1126/sciadv.adl5270 -
The International Journal of Oral &... Jun 2024To evaluate multiple risk factors of peri-implant bone loss.
OBJECTIVE
To evaluate multiple risk factors of peri-implant bone loss.
MATERIALS AND METHODS
A case-control study was conducted on patients who had received dental implants treatment from January 2018 to December 2021. Implants with bone loss were included in the case group, and implants with no bone loss were included in the control group. Risk factors including history of periodontitis, abutment connection type, implant surface, diameter, location, three-dimensional position, opposing dentition, adjacent teeth, prosthetic type, retention type and custom abutment were evaluated. A multivariate logistic regression model was used to evaluate these risk factors, providing corresponding odds ratios (ORs) with 95% confidence intervals (CIs).
RESULTS
A total of 776 implants in 479 patients were included in the analysis. The number of implants in the case group and the control group were 84 and 692, respectively. Cement-retained prostheses (OR=2.439, 95%CI=1.241-4.795) and nonplatform switch design (OR=2.055, 95%CI=1.167-3.619) were identified as weak risk factors. Horizontal deviation (OR=4.177, 95%CI=2.265-7.703) was a moderate risk factor. Vertical deviation (OR=10.107, 95%CI=5.280-19.347) and implants located in the mandibular molar region (OR=10.427, 95%CI=1.176-92.461) were considered high risk factors.
CONCLUSION
Implants in the molar region, cement retained, non-platform switch design, and poor three-dimensional implant positioning are identified as significant risk factors for peri-implant bone loss.
PubMed: 38941164
DOI: 10.11607/jomi.10939 -
Clinical Oral Investigations Jun 2024This study aimed to assess whether awake bruxism and masticatory muscle activity could be related to external root resorption (ERR) in second molars adjacent to impacted...
Is there a relationship between the presence of external root resorption in second molars adjacent to impacted mandibular third molars with awake bruxism and masticatory muscle activity?
OBJECTIVES
This study aimed to assess whether awake bruxism and masticatory muscle activity could be related to external root resorption (ERR) in second molars adjacent to impacted mandibular third molars.
MATERIALS AND METHODS
Sixty patients, with requests for a cone-beam, computed tomography, were divided into two groups: ERR (patients with ERR in the second molar, n = 30), and control group (n = 30). Awake bruxism was assessed through the Oral Behaviors Checklist (OBC) and an ecological momentary assessment (EMA). Surface electromyography (EMG) was used to assess the masseter and anterior temporal muscle function. Normality and homogeneity of variances were demonstrated. Descriptive analysis was performed, using the T-test and Chi-square test to compare the characteristics of the groups. A multiple regression model was performed.
RESULTS
The ERR group presented more non-functional oral activities related to awake bruxism than the control group, according to OBC (p = 0.027) and EMA (p = 0.035). In addition, the ERR group had higher EMG activity than the control group in rest and isotonic protocols (p < 0.05).
CONCLUSIONS
Awake bruxism and greater masticatory muscle activity seem to be related to the presence of ERR in second molars adjacent to impacted mandibular third molars.
CLINICAL RELEVANCE
The results of the present study can reinforce the theory that triggering ERR in the second molars adjacent to impacted mandibular third molars may be related to mechanical forces coming from the masticatory function.
Topics: Humans; Electromyography; Molar, Third; Female; Male; Tooth, Impacted; Adult; Cone-Beam Computed Tomography; Root Resorption; Molar; Bruxism; Masticatory Muscles; Mandible
PubMed: 38940883
DOI: 10.1007/s00784-024-05775-3 -
Developmental Dynamics : An Official... Jun 2024Previous studies have claimed that pharyngeal teeth in medaka (Oryzias latipes) are induced independent of retinoic acid (RA) signaling, unlike in zebrafish (Danio...
Differential retinoic acid sensitivity of oral and pharyngeal teeth in medaka (Oryzias latipes) supports the importance of pouch-cleft contacts in pharyngeal tooth initiation.
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.
PubMed: 38940489
DOI: 10.1002/dvdy.723 -
Frontiers in Bioscience (Landmark... Jun 2024Dental pulp stem cells (DPSCs) have self-renewal and multidirectional differentiation potentials. As such, DPSCs have a wide range of clinical applications. Low-level...
BACKGROUND
Dental pulp stem cells (DPSCs) have self-renewal and multidirectional differentiation potentials. As such, DPSCs have a wide range of clinical applications. Low-level laser therapy (LLLT) has positive photobiostimulatory effects on cell proliferation, angiogenesis, osteogenic differentiation, bone regeneration, and fracture healing. However, there have been few studies on the effect of low-energy lasers on DPSC proliferation.
METHODS
DPSCs were obtained from dental pulp tissue. The effects of LLLT on the proliferation of DPSCs and the associated mechanisms were investigated by culture and laser irradiation.
RESULTS
LLLT with energy densities of 3.5 J/cm2 and 14 J/cm2promoted the proliferation of DPSCs. Differential protein expression studies suggested the stimulation of DPSC proliferation by LLLT involved the PI3K-Akt and Rap1 signaling pathways, as well as the apoptosis-related pathway.
CONCLUSION
This preliminary study demonstrated that low-energy lasers have a pro-proliferative effect on DPSCs, and identified possible associated mechanisms. Our findings provide a theoretical basis for the clinical application of DPSCs and suggest novel strategies for the treatment of related diseases.
Topics: Dental Pulp; Cell Proliferation; Humans; Stem Cells; Low-Level Light Therapy; Cells, Cultured; Signal Transduction; Apoptosis; Cell Differentiation
PubMed: 38940041
DOI: 10.31083/j.fbl2906211 -
Frontiers in Cellular and Infection... 2024Recent studies have demonstrated a positive role of hyaluronic acid (HA) on periodontal clinical outcomes. This study aimed to investigate the impact of four different...
INTRODUCTION
Recent studies have demonstrated a positive role of hyaluronic acid (HA) on periodontal clinical outcomes. This study aimed to investigate the impact of four different HAs on interactions between periodontal biofilm and immune cells.
METHODS
The four HAs included: high-molecular-weight HA (HHA, non-cross-linked), low-molecular-weight HA (LHA), oligomers HA (OHA), and cross-linked high-molecular-weight HA (CHA). Serial experiments were conducted to verify the influence of HAs on: (i) 12-species periodontal biofilm (formation and pre-existing); (ii) expression of inflammatory cytokines and HA receptors in monocytic (MONO-MAC-6) cells and periodontal ligament fibroblasts (PDLF) with or without exposure to periodontal biofilms; (iii) generation of reactive oxygen species (ROS) in MONO-MAC-6 cells and PDLF with presence of biofilm and HA.
RESULTS
The results indicated that HHA and CHA reduced the bacterial counts in a newly formed (4-h) biofilm and in a pre-existing five-day-old biofilm. Without biofilm challenge, OHA triggered inflammatory reaction by increasing IL-1β and IL-10 levels in MONO-MAC cells and IL-8 in PDLF in a time-dependent manner, whereas CHA suppressed this response by inhibiting the expression of IL-10 in MONO-MAC cells and IL-8 in PDLF. Under biofilm challenge, HA decreased the expression of IL-1β (most decreasing HHA) and increased IL-10 levels in MONO-MAC-6 cells in a molecular weight dependent manner (most increasing CHA). The interaction between HA and both cells may occur via ICAM-1 receptor. Biofilm stimulus increased ROS levels in MONO-MAC-6 cells and PDLF, but only HHA slightly suppressed the high generation of ROS induced by biofilm stimulation in both cells.
CONCLUSION
Overall, these results indicate that OHA induces inflammation, while HHA and CHA exhibit anti-biofilm, primarily anti-inflammatory, and antioxidant properties in the periodontal environment.
Topics: Biofilms; Hyaluronic Acid; Humans; Reactive Oxygen Species; Fibroblasts; Cytokines; Monocytes; Periodontal Ligament; Cell Line; Interleukin-1beta; Interleukin-10
PubMed: 38938883
DOI: 10.3389/fcimb.2024.1414861 -
BMC Oral Health Jun 2024To examine the patterns of pretreatment facial soft tissue shape in orthodontic cases with premolar extraction using artificial intelligence (AI) and to investigate the... (Comparative Study)
Comparative Study
OBJECTIVE
To examine the patterns of pretreatment facial soft tissue shape in orthodontic cases with premolar extraction using artificial intelligence (AI) and to investigate the corresponding changes.
METHODS
One hundred and fifty-two patients who underwent orthodontic treatment with premolar extraction were enrolled. Lateral cephalograms were obtained before and after the treatment. For each record, the outlines of the nose-lip-chin profile and corresponding 21 cephalometric variables were extracted. The AI method classified pretreatment records into three subject groups based on the feature variables extracted from the outline. Dentoskeletal and soft tissue facial form changes observed after treatment were compared statistically (P < 0.05) between the groups using ANOVA. Multivariate regression models were used for each group.
RESULTS
Group 1 (n = 59) was characterized by Class II high-angle retrognathic mandible with an incompetent lip, group 2 (n = 55) by Class I malocclusion with retruded and thin lips, and group 3 (n = 38) by Class I malocclusion with an everted superior lip before treatment. The ratios of anteroposterior soft tissue to hard tissue movements in Group 1 were 56% (r = 0.64) and 83% (r = 0.75) for the superior and inferior lips, respectively, whereas those in Group 2 were 49% (r = 0.78) and 91% (r = 0.80), and 40% (r = 0.54) and 79% (r = 0.70), respectively, in Group 3.
CONCLUSIONS
The modes of facial form changes differed depending on the pre-treatment profile patterns classified by the AI. This indicates that the determination of the pre-treatment profile pattern can help in the selection of soft tissue to hard tissue movement ratios, which helps estimate the post-treatment facial profile with a moderate to high correlation.
Topics: Humans; Cephalometry; Face; Bicuspid; Tooth Extraction; Female; Male; Lip; Adolescent; Nose; Malocclusion, Angle Class I; Artificial Intelligence; Chin; Malocclusion, Angle Class II; Mandible; Tooth Movement Techniques; Child; Young Adult; Malocclusion
PubMed: 38937790
DOI: 10.1186/s12903-024-04512-2 -
BMC Oral Health Jun 2024The desirable properties of silver diamine fluoride (SDF) make it an effective agent for managing dental caries and tooth hypersensitivity. There are several clinical...
BACKGROUND
The desirable properties of silver diamine fluoride (SDF) make it an effective agent for managing dental caries and tooth hypersensitivity. There are several clinical instances that SDF application might precede the placement of direct tooth-colored restorations. On the other hand, SDF stains demineralized/carious dental tissues black, which might affect the esthetic outcomes of such restorations. Color is a key parameter of esthetics in dentistry. Therefore, this study aims to systematically review dental literature on color/color change of tooth-colored restorations placed following the application of SDF on dentine.
METHODS
Comprehensive search of PubMed, Embase, Scopus and ISI Web of Science databases (until August 2023) as well as reference lists of retrieved studies was performed. In vitro studies reported color or color change of tooth-colored restorative materials applied on SDF-treated dentine were included. Methodological quality assessment was performed using RoBDEMAT tool. Pooled weighted mean difference (WMD) and 95% confidence interval (95% CI) was calculated.
RESULTS
Eleven studies/reports with a total of 394 tooth-colored restorations placed following a) no SDF (control) or b) SDF with/without potassium iodide (KI)/glutathione dentine pre-treatments were included. Color change was quantified using ∆E formulas in most reports. The pooled findings for the comparison of resin-based composite (RBC) restorations with and without prior 38% SDF + KI application revealed no statistically significant differences in ∆E values at short- and long-term evaluations (~ 14 days: WMD: -0.56, 95% CI: -2.09 to 0.96; I: 89.6%, and ~ 60 days: WMD: 0.11; 95% CI: -1.51 to 1.72; I: 76.9%). No studies provided sufficient information for all the items in the risk of bias tool (moderate to low quality).
CONCLUSIONS
The limited evidence suggested comparable color changes of RBC restorations with and without 38% SDF + KI pre-treatment up to 60 days. The included studies lacked uniformity in methodology and reported outcomes. Further studies are imperative to draw more definite conclusions.
PROTOCOL REGISTRATION
The protocol of this systematic review was registered in PROSPERO database under number CRD42023485083.
Topics: Silver Compounds; Humans; Quaternary Ammonium Compounds; Fluorides, Topical; Dentin; Color; Dental Restoration, Permanent
PubMed: 38937760
DOI: 10.1186/s12903-024-04487-0 -
PloS One 2024The patterning cascade model of crown morphogenesis has been studied extensively in a variety of organisms to elucidate the evolutionary history surrounding postcanine...
OBJECTIVE
The patterning cascade model of crown morphogenesis has been studied extensively in a variety of organisms to elucidate the evolutionary history surrounding postcanine tooth form. The current research is the first to use a large modern human sample to examine whether the crown configuration of lower deciduous and permanent molars aligns with expectations derived from the model. This study has two main goals: 1) to determine if metameric and antimeric pairs significantly differ in size, accessory trait expression, and relative intercusp spacing, and 2) assess whether the relative distance among early-forming cusps accounts for observed variation in accessory cusp expression.
METHODS
Tooth size, intercusp distance, and morphological trait expression data were collected from 3D scans of mandibular dental casts representing participants of the Harvard Solomon Islands Project. Paired tests were utilized to compare tooth size, accessory trait expression, and relative intercusp distance between diphyodont metameres and permanent antimeres. Proportional odds logistic regression was implemented to investigate how the odds of greater accessory cusp expression vary as a function of the distance between early-developing cusps.
RESULTS/SIGNIFICANCE
Comparing paired molars, significant differences were identified for tooth size and cusp 5 expression. Several relative intercusp distances emerged as important predictors of cusp 6 expression, however, results for cusp 5 and cusp 7 did not match expected patterns. These findings support previous quantitative genetic results and suggest the development of neighboring crown structures represents a zero-sum partitioning of cellular territory and resources. As such, this study contributes to a better understanding of the foundations of deciduous and permanent molar crown variation in humans.
Topics: Humans; Tooth Crown; Molar; Dentition, Permanent; Morphogenesis; Tooth, Deciduous; Odontogenesis; Male; Child; Female
PubMed: 38935640
DOI: 10.1371/journal.pone.0304455 -
International Journal of Implant... Jun 2024This propensity score matching, multicenter, cross-sectional study was performed to examine the effects of various prosthetic methods for dental clinic outpatients with...
Effects of various prosthetic methods for patients with Kennedy Class I partial edentulism on oral hypofunction, subjective symptoms, and oral health-related quality of life.
PURPOSE
This propensity score matching, multicenter, cross-sectional study was performed to examine the effects of various prosthetic methods for dental clinic outpatients with Kennedy Class I partial edentulism (KCIPE) on oral hypofunction, subjective frailty symptoms, and oral health-related quality of life (QOL).
METHODS
Patients (n = 348) were classified into the following three groups for analysis: NT, patients with natural dentition providing intermaxillary contact in four occlusal supporting zones; RPD, patients with KCIPE who received removable partial dentures; and ISFP, patients with KCIPE who received implant-supported fixed prostheses. Participants' basic characteristics were recorded, and oral function tests were conducted. Subjective symptoms of physical and oral frailty were investigated via questionnaire. Oral health-related QOL was assessed using the Japanese short version of the Oral Health Impact Profile (OHIP-JP16). Propensity score matching was performed to adjust for patient background factors that could influence oral hypofunction in each group.
RESULTS
Compared with the ISFP group, the RPD group had significantly higher rates of poor oral hygiene, reduced occlusal force, decreased masticatory function, and declines in swallowing function and oral hypofunction; the odds ratio for oral hypofunction was 4.67. Compared with the ISFP group, the RPD group had significantly greater subjective symptoms of physical frailty and oral frailty, as well as higher OHIP scores.
CONCLUSIONS
Prosthetic treatment of KCIPE affected oral hypofunction, subjective frailty symptoms, and oral health-related QOL in dental clinic outpatients.
Topics: Humans; Quality of Life; Cross-Sectional Studies; Male; Female; Middle Aged; Oral Health; Jaw, Edentulous, Partially; Denture, Partial, Removable; Aged; Surveys and Questionnaires; Propensity Score; Dental Prosthesis, Implant-Supported; Denture, Partial, Fixed; Adult
PubMed: 38935335
DOI: 10.1186/s40729-024-00555-w