Clinical Evaluation of Single Versus Repeated Micro-Osteoperforations During Orthodontic Canine Retraction: A Randomized Clinical Trial.

INTRODUCTION: In the majority of orthodontic premolar extraction cases, the canine retraction phase is the most laborious procedure. This randomized clinical trial aimed to assess the effect of single versus repeated micro-osteoperforations (MOPs) during orthodontic canine retraction. METHODS: In this split-mouth study, two equal groups of 18 patients who required maxillary first premolar extractions and fixed orthodontic therapy were randomly assigned (n=9). In Group I, MOPs were only performed once on one site before retraction, whereas in Group II, MOPs were performed on one site repeatedly once a month for four months. In both groups, the contralateral control sites received no MOPs. The canines were retracted using mini-screws and closed-coil nickel-titanium springs. Using the patients' 3D models, the primary outcome measure at four months was the amount of orthodontic canine distal movement. The amount of anchorage loss (AL), degree of molar rotation (MR) and canine rotation (CR), and degree of canine tipping (CT) were measured as the secondary outcomes. The comparison of mean changes in the primary and secondary outcomes between the groups was done using the independent sample t-test (p<0.05). RESULTS: The rate of canine retraction, degree of CT, and rotation were not significantly different between the two groups (p>0.05). Additionally, there were no statistically significant variations in the maxillary first MR and the degree of AL (p>0.05). CONCLUSIONS: When maxillary canine retraction was performed with a single and repeated regimen of MOPs, comparable levels of distal CR and tipping were observed, along with an identical minimal degree of MR and AL.

Impact of Vitamin D Supplementation on Bone Mineral Density and All-Cause Mortality in Heart Transplant Patients.

Vitamin D (VD) deficiency is frequently reported in heart transplant (HT) recipients and routinely supplemented. However, the efficacy of VD supplementation on bone mineral density (BMD) and its association with all-cause mortality is underinvestigated. The VD levels and BMD were studied for two years, and the association of VD and BMD with all-cause mortality risk was investigated. Ninety-six HT patients (38.18 ± 12.10 years old; 74% men) were followed up during VD, Ca, and Mg supplementation. Anthropometric measurements, BMD by Dual-energy X-ray absorptiometry (DEXA) scan, VD concentrations, and related biochemical parameters were analyzed before, 1 year, and 2 years after HT. Despite significant improvement of VD3 and 25-hydroxy VD (25OHVD) levels especially in the men, BMD parameters were insignificantly changed. After 2 years, the all-cause mortality rate was 15.6%. High pretransplant levels of 25OHVD failed to improve the survival probability. Cox's regression showed a 32.7% increased hazard ratio for each unit increase in body mass index (95% CI: 1.015-1.733, p = 0.038), in the VD-deficient group rather than in the VD-sufficient one. In conclusion, VD supplementation improves the biochemical status, especially in VD-deficient HT. However, its impact on the BMD and mortality was not as usually expected. Further investigation of the disturbed VD metabolism in HT is warranted.

Three-dimensional assessment of transverse dentoskeletal mandibular dimensions after utilizing two designs of fixed mandibular expansion appliance: A prospective clinical investigation.

The aim of this clinical study was to evaluate and compare the dentoskeletal transverse mandibular arch dimensions following the use of two designs of fixed mandibular expanders using cone beam computed tomography (CBCT). Twenty orthodontic patients, 12 females and 8 males, with mean age of 13.4 ± 0.5 years were selected and randomly divided into two equivalent groups; group A consisted of 10 patients (4 boys, 6 girls) who were treated with modified Williams expander and group B consisted of 10 patients (4 boys, 6 girls) who were treated with a two-arm fixed expander. Consistent expansion instructions were given to all patients according to a standardized slow protocol of one quarter turn twice/week for both expanders. Routine orthodontic records as well as mandibular CBCTs were obtained before (T1) and immediately after expansion (T2) to estimate changes in dentoskeletal mandibular transverse dimensions. The data was statistically analyzed and the significance level was set at p ≤ 0.05. Mandibular intercanine, inter-premolar, intermolar widths; and arch perimeter were significantly increased (p ≤ 0.05) following expansion with both fixed expanders. However, the changes in inter-premolar width, intercanine width, and arch perimeter were significantly augmented in two-arm fixed expander group than modified Williams's group. In contrast, their effects on the skeletal mandibular body width were non-significant (p > 0.05). Both expanders yielded significant and equivalent dentoalveolar effects that were more evident with two-arm fixed expander than the William one. Both fixed designs enhanced mandibular transverse dental dimensions; however, they were unsuccessful to create any considerable skeletal effects.

Preliminary fabrication and characterization of electron beam melted Ti-6Al-4V customized dental implant.

The current study was aimed to fabricate customized root form dental implant using additive manufacturing technique for the replacement of missing teeth. The root form dental implant was designed using Geomagic™ and Magics™, the designed implant was directly manufactured by layering technique using ARCAM A2™ electron beam melting system by employing medical grade Ti-6Al-4V alloy powder. Furthermore, the fabricated implant was characterized in terms of certain clinically important parameters such as surface microstructure, surface topography, chemical purity and internal porosity. Results confirmed that, fabrication of customized dental implants using additive rapid manufacturing technology offers an attractive method to produce extremely pure form of customized titanium dental implants, the rough and porous surface texture obtained is expected to provide better initial implant stabilization and superior osseointegration.

Orthopedic Effect of Chin Cup during Mixed Dentition Stage.

INTRODUCTION: Chin cup (CC) therapy has been used as the traditional appliance for treating class III malocclusion during mixed dentition period. The aim of this study was to investigate the effect of CC on the improvement of skeletal and dentoalveo-lar skeletal changes in class III patients during mixed dentition stage. MATERIALS AND METHODS: A total of 30 patients (7-9 years old) with skeletal class III malocclusion were selected based on clinical and cephalometric examination. Out of 30 patients, 20 underwent CC therapy. All orthodontic records and measurements were taken before and after treatment. Similar records were collected from the control group. The lateral cephalometric films were traced before and after treatment and analyzed. RESULTS: There was a significant improvement in maxillary and the mandibular skeletal measurements after CC therapy. Improvement of ANB angle and an increase in Wits appraisal have been detected in the treated group according to intermaxillary skeletal variables. CONCLUSION: The study concluded that the CC therapy is effective for correcting skeletal class III malocclusion along with positive changes in the dentoskeletal variables during the mixed dentition stage.

Influence of premolar extraction or non-extraction orthodontic therapy on the angular changes of mandibular third molars.

AIM: To compare the angular changes of the third molars relative to the occlusal plane and to the second molar long axis in extraction group and compare these changes with a non extraction group. MATERIALS AND METHODS: The study included pre and post treatment panoramic radiograph records of 90 subjects treated by first premolar extractions and 90 subjects who had been treated with non extraction orthodontic therapy (n = 90). Two angular variables were measured. Firstly, the angle between the long axis of the third molar and the occlusal plane (M3-OP) and secondly, the angle between the long axis of the third molar and the long axis of the second molar (M3-M2). Data were analyzed by paired and student's t-test. RESULT: The analyzed data to assess the changes in the third molar angulation from pretreatment to post treatment did not vary significantly in both the groups (p < 0.05). Both the groups showed decreased angular values. The M3-OP angular difference was (-7.3 ± 2.45) in extraction group as compared to (-5.85 ± 1.77) in non extraction group. The M3-M2 angular difference of (-4.26 ± 3.11) in extraction group and (-2.98 ± 1.74) in non-extraction group was observed. CONCLUSION: Extraction of premolars did not demonstrate considerable changes on the angulation of the third molars. The factors other than premolar extractions may influence the angulation of the third molars.

Influence of tooth brushing on adhesion strength of orthodontic brackets bonded to porcelain.

BACKGROUND: Adhesive resin composite, which is used to bond orthodontic bracket to tooth surface is exposed to the influence of wear by tooth brushing and wear may influence loosening of the bracket. OBJECTIVE: The aim of this study was to evaluate in vitro the effect of tooth brushing on the adhesion strength of orthodontic brackets bonded to surface treated porcelain. METHOD: A total of 90 glazed porcelain fused to metal facets (PFM) were randomly assigned into 3 groups according to the surface treatment to be received. Group 1 was conditioned with hydrofluoric acid (HF), group 2 conditioned with grit-blasting (GB) and group 3 conditioned with tribochemical silica coating (RC). The groups were evaluated for surface roughness (Ra) before and after surface treatment. Next, 15 samples from each group were subjected to brushing and remaining 15 samples served as the baseline (n=15). Adhesion strength (shear bond strength)was recorded using a universal testing machine. Data collected were analyzed by ANOVA and Tukey's multiple comparison post hoc analysis. RESULTS: Tooth brushing decreased the bond strength in all groups. The highest adhesion strength (baseline and after brushing) was observed in group 3 (26.8 ± 1.77 MPa and 23.57 ± 1.02 MPa) and the lowest was found in group 1 (9.6 ± 1.5 MPa and 5.87 ± 0.77 MPa). Group 3 specimens exhibited the highest Ra (1.24 ± 0.08). CONCLUSION: It was found that tooth brushing of the exposed adhesive resin composite at the bracket-bonding substrate interface lowers the bonding strength regardless of the surface treatment of the substrate.

Assessment of DNA Damage in Leukoplakia Patients with Different Degrees of Dysplasia.

BACKGROUND: Single cell gel electrophoresis (SCGE) assay also known as comet assay is a rapid and highly sensitive fluorescent molecular technique for detecting various forms of deoxyribonucleic acid (DNA) damage at individual cellular level. MATERIALS AND METHODS: The present study was done to detect the extent of DNA damage in oral leukoplakia (OL) and compare with normal individuals. The sample population was obtained from an outpatient clinic of a tertiary teaching dental institute. A total of 36 consecutive patients with leukoplakia and 10 healthy normal volunteers were recruited for the study and assessed for the extent of DNA damage using SCGE following clinical diagnosis and histological grading. Peripheral blood was obtained by venipuncture and SCGE assay was performed. Mean comet tail length was recorded and analyzed statistically to compare the extent of damage in each group. RESULTS: The mean comet tail length seen in leukoplakia patients with moderate to severe dysplasia was 1.25 ± 0.14 mm while for the control subjects, it was 0.31 ± 0.10 mm. The difference was statistically significant (p = 0.000). On comparing within the grades of leukoplakia, a progressive trend of increasing tail length was observed with increasing grades of dysplasia. CONCLUSION: Deoxyribonucleic acid damage as measured by SCGE is seen in leukoplakia. A stepwise increase in DNA damage levels from healthy controls, through patients with non-dysplastic epithelium to varying grades of dysplasia has been observed indicating the extent of DNA damage in this high risk group.

Effect of honey in preventing gingivitis and dental caries in patients undergoing orthodontic treatment.

OBJECTIVES: THIS STUDY WAS CONDUCTED TO INVESTIGATE THE FOLLOWING: (1) the effects of chewing honey on plaque formation in orthodontic patients, (2) the effect of chewing honey on dental plaque bacterial counts, (3) determine if honey possesses antibacterial effects on bacteria recovered from plaques. METHODS: Female orthodontic patients (n = 20, 12-18 years of age) participated in this randomized controlled study. The effects of honey were compared to treatment with either 10% sucrose or 10% sorbitol that served as positive and negative controls, respectively. The pH of plaque was measured using a digital pH meter prior to baseline and at 2, 5, 10, 20, and 30 min after chewing honey or rinsing with control solutions and the numbers of Streptococcus mutans, Lactobacilli, and Prophymonas gingivalis in respective plaques were determined. The antibacterial activity of honey was tested against commonly used antibiotics using the disk diffusion method. RESULTS: Significant differences in pH were observed in the honey and sucrose groups compared to the pH observed in the sorbitol group (p â©½ 0.001). The maximum pH drop occurred at 5 min in both the honey and sucrose groups; however the pH in the honey group rapidly recovered 10-20 min after exposure and did not drop below the critical decalcification pH of 5.5. On the other hand, the pH following sucrose exposure fell <5.5 and was associated with a 30 min recovery time. The pH observed for the sorbitol group did not change over time. Bacterial counts were significantly reduced in the honey group compared to the other treatment groups (p â©½ 0.001) and honey significantly inhibited the growth of all studied strains compared to inhibition observed with antibiotics (p â©½ 0.001). CONCLUSIONS: Honey can be used as an alternative to traditional remedies for the prevention of dental caries and gingivitis following orthodontic treatment.