Morphological alterations, activity, mRNA fold changes, and aging changes before and after orthodontic force application in young and adult human-derived periodontal ligament cells.

BACKGROUND: The response of periodontal ligament cells (PDLC) from adult subjects in comparison to those obtained from younger ones to mechanical forces has been a matter of interest recently because of induced senescent changes. This study evaluated and compared cell surface changes and activity, integrin beta 1, and ß-actin mRNA fold changes as well as klotho protein secretion capabilities of PDLC from young and adult donors before and after subjecting to orthodontic forces. METHODS: A total of 40 subjects with bimaxillary dentoalveolar protrusion requiring extraction of first premolars for orthodontic treatment were selected and divided into two groups. Force ranging from 80 to 90 g was applied to maxillary first premolars and extraction was carried out at two different time periods-pre-treatment (control group) and 28 days after force application (experimental group). Periodontal ligament was obtained, and cell surface changes and activity were observed with atomic force microscopy (AFM) and fluorescent tagging. mRNA fold change of integrin beta-1 and ß-actin mRNA, as well as beta-galactosidase assay, was performed, and levels of klotho protein were evaluated. RESULTS: AFM nanoindentation and fluorescent tagging indicated increased surface morphological changes in younger cells compared to adult ones. We observed a decrease in integrin beta 1 but an increase in ß-actin mRNA levels in PDLC obtained from younger subjects compared to adults, while an increase was observed in SA-ß-GAL from adult cells. The level of klotho protein was lower in adult cells in comparison to younger ones. LIMITATIONS: Large sample studies are required to find out a variation in aging characteristics between young and adult PDLC. CONCLUSIONS: The study observed significant differences between PDLC obtained from younger and adult subjects in response to orthodontic force application.

Perceptions of a comprehensive dental care teaching clinic among stakeholders in a dental teaching hospital in South India: A baseline assessment.

BACKGROUND: When the dentist starts practicing independently, they need to plan and treat comprehensively and prioritise the procedures accordingly. This contrasts with dental students learning years where they deal with only a clinical subject during a fixed period. To improve this scenario a comprehensive dental care teaching clinic was introduced, and baseline assessment was performed. METHODS: The perceptions of patients, dental undergraduate students, clinical instructors, and clinic co-ordinators regarding Comprehensive Dental Care was evaluated by a cross sectional survey. The questionnaire was developed through a focus group discussion and content validation was performed by experts. Three domains including orientation to the clinics, clinical training of undergraduates and clinic management were assessed. Descriptive statistics were performed using SPSS. RESULTS: The results reveal, 53.5% of undergraduate students and 61.3% of clinic instructors agreeing that students trained under comprehensive system can confidently manage patients independently. Good collaboration (80%) among the dental team and regular monitoring of the clinic management (80%) were reported by clinic co-ordinators. The challenges ahead for this teaching clinic includes instrument and facilities availability, which has found to higher disagreement percentages by undergraduate students (43.7%), clinic instructors (38.7%) as well as clinic co-ordinators (50%). Patient satisfaction for all three domains were noted to be high. CONCLUSION: With the introduction of the comprehensive dental care teaching clinic better patient management and improved clinical training of undergraduate students were reported by the stakeholders. This new system is a major shift in dental service delivery and can be adopted to similar settings to improve patient care and dental education.

Periodontal ligament cells in adolescents and adults: Genetic level responses to orthodontic forces.

INTRODUCTION: Periodontal ligament cells (PDLC) respond to the application of mechanical forces by releasing various molecules that participate in bone remodeling. Whether these cellular reactions take place at the same rate in adolescent and adult patients is not known. In this study, we aimed to evaluate differences in genetic expression, if any, between the release of various inflammatory mediators from PDLC in adolescent and adult patients before and after the application of orthodontic forces. METHODS: Forty subjects with bimaxillary dentoalveolar protrusion requiring extraction of first premolars for orthodontic treatment were selected and divided into 2 groups. Group A included 20 adolescents (aged 12-20 years), and group B included 20 adults (aged 35-50 years). Then, 35-50 g of force were applied to the maxillary first premolars, and teeth were extracted at different periods: pretreatment (control group), 7 days, 14 days, and 28 days (experimental group). The periodontal ligament was scraped from the middle third of the root, and the beta-galactosidase assay was performed in the control group. RNA extraction, DNase treatment, quantitative polymerase chain reaction, and complementary DNA synthesis were performed in the experimental group. RESULTS: Adult PDLC exhibited senescent changes through increased beta-galactosidase activity. The increase in the inflammatory response and bone resorption in adult patients was evident by increased prostaglandin E2, IL1B, and acid phosphatase mRNA expression levels. Controlled bone formation response by adolescent PDLC was evident from increased ALP and BGLAP mRNA levels and a balanced receptor activator of nuclear factor kappa-Β ligand/OPG ratio. CONCLUSIONS: The study could identify the reasons behind the differential response of adolescent and adult PDLC to orthodontic mechanics.

Three-Dimensional Finite Element Analysis of Osseointegrated Implants Placed in Bone of Different Densities With Cemented Fixed Prosthetic Restoration.

A key factor for a successful dental implant is the manner in which stresses are transferred to the surrounding bone. Strength of bone is directly related to its density. Maximum stresses are reported to be incurred by the crestal cortical bone surrounding the implant. Displacement of implants is significantly higher in soft cancellous bone than dense bone. Implants are often placed in bone of different densities to support fixed dental prostheses. This study was aimed at assessing stress and deformation generated by osseointegrated implants placed in bone of different densities on a cemented fixed prosthesis when subjected to static and dynamic loading. A 3-dimensional finite element analysis was done on a computer-aided design model simulating maxillary bone segment with 2 different bone densities (D2 and D4). The effect of loading was evaluated at the implant-bone interface, implant-abutment interface, abutment, implant abutment connecting screw, cementing medium, and fixed prosthesis. Stresses were calculated using von Mises criteria calibrated in megapascals and deformation in millimeters. These were represented in color-coded maps from blue to red (showing minimum to maximum stress/deformation), depicted as contour lines with different colors connecting stress/deformation points. The study found greater von Mises stress in D2 than D4 bone, and in D2 bone the component with higher stress was the implant. Deformation was greater in D4 than D2 bone, and in D4 bone the abutment-prosthesis interface showed more deformation.

Management of abutment screw loosening: review of literature and report of a case.

Dental implant restoration has been widely accepted as one of the treatment modalities to replace missing teeth and to restore human masticatory function. The use of root form endosseous implant has increased considerably and this restorative option has become more refined with the introduction of newer designs and concepts. Long term post placement studies have reported prosthetic complications, including screw loosening, screw fracture, framework and implant fracture. Abutment screw loosening is the second most common cause of failure of implant supported restoration, next to loss of osseointegration. This is more seen in single implant supported restoration. Management of screw loosening is challenging and this clinical report describes the management of an implant abutment screw loosening of upper anterior teeth with minimal damage to the existing restoration making it possible to be reused and a literature review on the various factors associated with abutment screw loosening.

Etiquette in scientific publishing.

Publishing a scientific article in a journal with a high impact factor and a good reputation is considered prestigious among one's peer group and an essential achievement for career progression. In the drive to get their work published, researchers can forget, either intentionally or unintentionally, the ethics that should be followed in scientific publishing. In an environment where "publish or perish" rules the day, some authors might be tempted to bend or break rules. This special article is intended to raise awareness among orthodontic journal editors, authors, and readers about the types of scientific misconduct in the current publishing scenario and to provide insight into the ways these misconducts are managed by the Committee of Publishing Ethics. Case studies are presented, and various plagiarism detection software programs used by publishing companies are briefly described.

Long-term changes in thickness, live/dead bacterial ratio, and mineral content in biofilm on ceramic and stainless steel orthodontic attachments.

PURPOSE: Fixed orthodontic appliances induce biofilm deposition, which harbors a microbial population harmful to the periodontal health of the individual. The present study evaluated the changes in thickness, live/dead bacterial ratio, and mineral content in dental biofilm over 6 months in patients with either stainless steel or ceramic orthodontic attachments. METHODS: Eighty patients who require fixed orthodontic appliance treatment with first premolar extraction for correcting their malocclusion were selected and bonded with either stainless steel or ceramic orthodontic attachments on the buccal side. The attached buttons were retrieved at different periods-1 week, 1 month, 3 months, and 6 months. They were stained and visualized through confocal microscopy to detect biofilm thickness and the ratio of live/dead bacteria. X­ray diffraction was used to identify the presence of calcium and phosphorous. RESULTS: Ceramic attachments showed a greater increase in biofilm thickness in comparison to stainless steel attachments except in the initial 1­week evaluation. A higher live/dead bacterial ratio was observed in stainless steel attachments than in their ceramic counterparts at all four evaluation periods. Both stainless steel and ceramic surfaces exhibited the presence of mineral deposition (calcium and phosphorous) at all periods. CONCLUSIONS: More biofilm adhesion was observed over ceramic surfaces than over stainless steel orthodontic attachments. Stainless steel attachments exhibited biofilm with a higher live/dead bacterial ratio than their ceramic counterparts at all evaluation periods. The presence of calcium and phosphorous in the adhered biofilm, pointing toward its calcification process, was identified.

Relevance of Recurring Esthetic Dental (RED) proportion and golden proportion among patients attending a tertiary care center at Kochi, Kerala.

Background: Smile plays an essential part in facial esthetics. There have been some mathematical and geometric theories regarding smile designing in literature. The purpose of the study was to assess RED proportion and golden proportion among patients attending a tertiary care centre at Kochi, Kerala. Methods: Standardised frontal images of 106 subjects, 50 male and 56 females, were captured in the age bracket of 18-25 years. Pictures of the patients were obtained using a DSLR camera (CANON EOS-60D) and then digitally analysed. Measurements of each maxillary anterior tooth was recorded and then the theories of RED and golden proportion were employed and the figures recorded were statistically analysed. Results: The RED proportion was observed to be inconsistent, while progressing distally, Golden proportion was observed to be in 6-29% of the existing subject population. Conclusion: Within the limited sample size of the study, RED (Recurring Esthetic Dental) proportion and golden proportion failed to exist in Keralites.

Heat shock protein 70 and the extent of nuclear damage in periodontal ligament compression side cells with orthodontic force application - An ex-vivo evaluation.

OBJECTIVE: Increased levels of heat shock proteins after several types of stress play a central role in cellular homeostasis allowing for continued cell survival. This study was aimed at quantitatively analysing the expression pattern of major damage associated molecular patterns (DAMPs) - HSP70, and the amount of nuclear damage incident in periodontal ligament compression side cells. MATERIAL AND METHODS: Sixteen subjects with bimaxillary dentoalveolar protrusion requiring extraction of all first premolars as part of orthodontic treatment were selected. Extractions were carried out pretreatment from control group. In the experimental group, a buccally directed spring, with force range of 70-120gms promoting bodily movement of maxillary first premolars was placed. Periodontal ligament was scraped from the middle third of the root from the compression side, the cells were isolated and cultured followed by HSP70 protein estimation with western blot analysis and the extend of nuclear damage was assessed with COMET assay. RESULTS: Western Blot analysis of HSP70 revealed a statistically significant increased expression of HSP70 (P<0.05; CI=95%) in the force applied group compared with the control group. COMET assay could demonstrate significant amount of nuclear fragmentation in the compression side periodontal ligament cells in comparison to control group (P<0.05; CI=95%). CONCLUSIONS: All these findings demonstrated, for the first time, that orthodontic force application augments release of HSP70 from periodontal ligament cells as a measure to restore tissue homeostasis. Further the study demonstrated that orthodontic forces induce DNA fragmentation, which is quantified more than double the amount observed in the control group.

Role of basic biological sciences in clinical orthodontics: a case series.

INTRODUCTION: Orthodontic therapy is based on interaction between mechanics and biology. Basic biologic research aims at developing a better understanding of the mechanism of transformation of mechanical energy into biologic reactions, and exposing the reasons for iatrogenic tissue damage in orthodontics. Previous research has shown that inflammation is a major part of the biologic response to orthodontic forces. In inflammation, signal molecules that originate in remote diseased organs can reach strained paradental tissues and exacerbate the inflammatory process, leading to tissue damage. METHODS: Our case series includes 3 patients, each having had systemic diseases and malocclusion. One had diabetes mellitus, Hashimoto's thyroiditis, and depression. Concern about the possible effect of these conditions on the well-being of the teeth and their surrounding tissues compelled the orthodontist to choose not to treat this patient. The other 2 patients had allergies, and 1 also had bronchial asthma and bruises. RESULTS: Although these conditions are thought to be risk factors for root resorption, these patients received orthodontic treatment for 2 and 3.5 years, respectively. At the end of treatment, both had excessive root resorption of many teeth. In 1 patient, this damage led to the loss of most maxillary teeth. CONCLUSIONS: Basic research should continue to address questions related to the biologic mechanisms of tooth movement on tissue, cellular, and molecular levels. Moreover, this research should continue to identify risk factors that might jeopardize the longevity of treated teeth. Such basic research should promote the development of new tissue-friendly and patient-friendly therapeutic methods.

Time-dependent variation in expression patterns of Lysyl Oxidase, Type I Collagen and tropoelastin mRNA in response to orthodontic force application.

OBJECTIVE: Orthodontic tooth movement is characterized by reorganization of collagen and elastin fibers. Lysyl oxidase (LOX), the copper containing amine oxidase is involved in the post translational stabilization of these fibers. The objective of this study was to quantitatively evaluate mRNA expression of lysyl oxidase, type I collagen (COL I) and tropoelastin and find out time dependent correlation in expression of lysyl oxidase mRNA with Type I collagen or tropoelastin messenger RNA (mRNA). DESIGN: Study evaluated 12 samples grouped into 4, Group A (control), experimental groups B, C and D collected after 7, 14, 28 days of force application respectively. mRNA expression was assessed using qRT-PCR. RESULTS: The mRNA expression of Type I Collagen increased 15, 39, 20-fold, lysl oxidase increased 16, 27, 14-fold and tropoelastin decreased 8, 5, 13-fold in groups B, C and D when compared to control. The results were found to be statistically significant when one-way analysis of variance (ANOVA) and post hoc test was performed. Tropoelastin mRNA showed negative correlation with that of lysl oxidase (r2= -0.74) and COL1 (r2= -0.42). CONCLUSIONS: Force application resulted in time-dependent variation in expression of type I collagen, lysl oxidase and tropoelastin mRNA. Type I Collagen and lysl oxidase mRNA expression peaked in samples collected after 14 days of force application, while decreased expression pattern for tropoelastin mRNA was observed.

Does the clinical phenotype of mucolipidosis-IIIγ differ from its αß counterpart?: supporting facts in a cohort of 18 patients.

Mucolipidosis-IIIγ (ML-IIIγ) is a recessively inherited slowly progressive skeletal dysplasia caused by mutations in GNPTG. We report the genetic and clinical findings in the largest cohort with ML-IIIγ so far: 18 affected individuals from 12 families including 12 patients from India, five from Turkey, and one from the USA. With consanguinity confirmed in eight of 12 families, molecular characterization showed that all affected patients had homozygous pathogenic GNPTG genotypes, underscoring the rarity of the disorder. Unlike ML-IIIαß, which present with a broader spectrum of severity, the ML-III γ phenotype is milder, with onset in early school age, but nonetheless thus far considered phenotypically not differentiable from ML-IIIαß. Evaluation of this cohort has yielded phenotypic findings including hypertrophy of the forearms and restricted supination as clues for ML-IIIγ, facilitating an earlier correct choice of genotype screening. Early identification of this disorder may help in offering a timely intervention for the relief of carpal tunnel syndrome, monitoring and surgery for cardiac valve involvement, and evaluation of the need for joint replacement. As this condition may be confused with rheumatoid arthritis, confirmation of diagnosis will prevent inappropriate use of immunosuppressants and disease-modifying agents.

Characterization of posed smile by using visual analog scale, smile arc, buccal corridor measures, and modified smile index.

INTRODUCTION: Smile evaluation and designing are important; recent emphasis on the soft tissues has been on par with that on the hard tissues in orthodontic diagnosis and treatment planning. This importance has not yet gained proper attention, and smile analysis is often ignored in clinical examinations. We attempted a comprehensive evaluation of smile characteristics with the following aims: (1) evaluation of perception differences, if any, between dental specialists and laypersons; and (2) quantification of smile characteristics with the smile arc, buccal corridor measurements, and a modified smile index (MSI). METHODS: The sixty subjects included in the study had an age range of 18 to 25 years (mean, 21 years) with equal numbers of men and women. Frontal posed smile photographs were taken of all subjects. The study had 2 parts. Analysis of perception differences between dental specialists and laypersons was performed with a visual analog scale. Quantification of smile characteristics was done with smile-arc evaluation for consonance or non-consonance, buccal corridor measurements, the MSI, and comparisons of the MSI with the facial index and the mandibular width-facial height index. RESULTS: There was no perception difference between the specialists and the laypersons on overall smile evaluation. Women had more consonant smile arcs than men, and there was high correlation between the right and left buccal corridor spaces in men and women. The MSI showed no correlation to the facial index, but there was a negative correlation of the MSI with the mandibular width-facial height index. CONCLUSIONS: Smile analysis should be an important aspect of orthodontic diagnosis and treatment planning. Orthodontists should not disturb consonant smiles but create them with proper bracket positioning. The MSI, with negative correlation with the mandibular width-facial height index, warrants further evaluation with a larger sample to validate its clinical use and to develop a predictive approach of its relationship.