Madhur Upadhyay

Bio: Madhur Upadhyay is an academic researcher from University of Connecticut. The author has contributed to research in topics: Anterior teeth & Molar. The author has an hindex of 18, co-authored 75 publications receiving 1048 citations. Previous affiliations of Madhur Upadhyay include University of Connecticut Health Center.

Dynamic smile analysis: changes with age.

Abstract: Introduction The objective of this study was to define age-related changes in the smile. The areas of interest were upper lip length at smile and repose, upper lip thickness at smile and repose, maxillary incisal display at smile, interlabial gap height at smile, smile index, percentage of buccal corridors, intercommissural width at rest, smile height, and smile arc. A secondary objective was to study the perioral changes from rest to smile and compare them on the basis of age. Methods Video equipment was used to capture images of 261 subjects, who were divided into 5 groups by age. Two frames for each subject were selected, 1 frame representing the lips at rest and the other representing the widest smile. After 40 subjects were excluded, the data for the remaining 221 were analyzed by using 1-way analysis of variance (ANOVA) with the Fisher LSD post-hoc test. Results There was a decrease of 1.5 to 2 mm in maxillary incisor display during smile with increasing age, but the smile index showed a significant increase. In accordance with some other studies, most subjects (78%) had average smile height. No subject in the 50 and over age group had a high smile, and no subject in the 15-to-19 year group had a low smile. All dynamic measurements indicated a pattern of decreasing change from rest to smile, especially evident after ages 30 to 39 years. Conclusions This study helps to establish age-related dynamic norms. As a person ages, the smile gets narrower vertically and wider transversely. The dynamic measures indicate that the muscles' ability to create a smile decreases with increasing age.

Treatment effects of mini-implants for en-masse retraction of anterior teeth in bialveolar dental protrusion patients: A randomized controlled trial

Abstract: Introduction: The purpose of this randomized controlled trial was to quantify the treatment effects of en-masse retraction of anterior teeth with mini-implants as anchor units in bialveolar dental protrusion patients undergoing extraction of all 4 first premolars. Methods: A total of 40 patients (mean age, 17.5 years; SD, 3.2 years) were randomly assigned either to group 1 (G1), anterior space closure with mini-implants as anchor units, or group 2 (G2), anterior space closure with conventional methods of anchorage (without mini-implants). Skeletal, dental, and soft-tissue changes were analyzed in both groups on lateral cephalograms taken before retraction and after space closure. Results: Student paired and unpaired t tests were used to analyze the treatment changes in the 2 groups. For the skeletal parameters, a statistically significant decrease in the facial vertical dimensions was seen in G1, but the variables in G2 showed no significant differences ( P >0.05). Anchorage loss, in both the horizontal and vertical directions, was noted in G2, whereas G1 showed distalization (anchorage gain) and intrusion of molars. Although the soft-tissue response was variable, facial convexity angle, nasolabial angle, and lower lip protrusion had greater changes in G1. No differences were found in the amount of upper lip retraction between the groups ( P >0.05). Conclusions: Mini-implants provided absolute anchorage to allow greater skeletal, dental, and esthetic changes in patients requiring maximum anterior retraction, when compared with other conventional methods of space closure. The treatment changes were favorable. However, no differences in the mean retraction time were noted between the 2 groups.

Mini-implant anchorage for en-masse retraction of maxillary anterior teeth: A clinical cephalometric study

Abstract: Introduction This study was conducted to determine the efficiency of mini-implants as intraoral anchorage units for en-masse retraction of the 6 maxillary anterior teeth when the first premolars are extracted compared with conventional methods of anchorage reinforcement. Methods Thirty patients requiring high anchorage after extraction of the maxillary first premolars were selected for this study. They were divided into 2 groups of 15 each. In the first group (G1), mini-implants were used for en-masse retraction; in the second group (G2), conventional methods of anchorage preservation were followed. Horizontal, vertical, and angular positions of the maxillary first molar and central incisor were evaluated cephalometrically before and after orthodontic retraction. Results The maxillary first molars in the G1 patients showed net distal movement of 0.55 mm, and mesial movement of 1.95 mm was found in G2. The differences were statistically significant. Distal tipping of the first molar of −0.13° ± 3.63° was seen in G1, and mesial tipping of 3.7° ± 3.9° was observed in G2. No significant differences were found in the rates of incisor retraction between the 2 groups. However, G1 showed more than 2 mm of incisor intrusion; this was statistically significant. Conclusions Mini-implants are efficient for intraoral anchorage reinforcement for en-masse retraction and intrusion of maxillary anterior teeth. No anchorage loss was seen in either the horizontal or the vertical direction in G1 when compared with G2. However, a statistically significant decrease in intermolar width was noted in G1.

Microdamage of the cortical bone during mini-implant insertion with self-drilling and self-tapping techniques: A randomized controlled trial

Abstract: Introduction The purpose of this research was to evaluate microdamage accumulation after mini-implant placement by self-drilling (without a pilot hole) and self-tapping (screwed into a pilot hole) insertion techniques. The null hypothesis was that the mini-implant insertion technique would have no influence on microcrack accumulation and propagation in the cortical bones of the maxillae and mandibles of adult hounds. Methods Mini-implants (n = 162; diameter, 1.6 mm; length, 6 mm) were placed in the maxillae and mandibles of 9 hounds (12-14 months old) with self-drilling and self-tapping insertion techniques. The techniques were randomly assigned to the left or the right side of each jaw. Each hound received 18 mini-implants (10 in the mandible, 8 in the maxilla). Histomorphometric parameters including total crack length and crack surface density were measured. The null hypothesis was rejected in favor of an alternate hypothesis: that the self-drilling technique results in more microdamage (microcracks) accumulation in the adjacent cortical bone in both the maxilla and the mandible immediately after mini-implant placement. A cluster level analysis was used to analyze the data on the outcome measured. Since the measurements were clustered within dogs, a paired-samples t test was used to analyze the average differences between insertion methods at both jaw locations. A significance level of 0.05 was used for both analyses. Results The self-drilling technique resulted in greater total crack lengths in both the maxilla and the mandible (maxilla: mean difference, 18.70 ± 7.04 μm/mm 2 ; CI, 13.29-24.11; mandible: mean difference, 22.98 ± 6.43 μm/mm 2 ; CI, 18.04-27.93; P 2 ; CI, 3.34-17.43; mandible: mean difference, 11.28 ± 3.41 μm/mm 2 ; CI, 8.65-13.90; P Conclusions This study demonstrated greater microdamage in the cortical bones of adult hounds in both the maxilla and the mandible by the self-drilling insertion technique compared with the self-tapping technique.

Titanium screw anchorage for protraction of mandibular second molars into first molar extraction sites.

Abstract: This report describes the orthodontic treatment of a 20-year-old woman with missing mandibular first molars. Titanium screws were placed in the buccal alveolar bone between the roots of the first and second premolars to provide absolute anchorage for protraction of the second molars into the atrophic edentulous areas. More than 8 mm of protraction was done in 15 months without significant lingual tipping of the incisors. Increases in alveolar ridge width and vertical bone height were noted mesial to the second molar. Good posterior occlusion was achieved and has been maintained for 1 year after active treatment.

A Prospective Study of the Risk Factors Associated with Failure of Mini-implants Used for Orthodontic Anchorage

Abstract: Purpose: The aim of this prospective clinical study was to assess the risk factors associated with failure of mini-implants used for orthodontic anchorage. Materials and Methods: A total of 140 miniimplants in 44 patients, including 48 miniplates and 92 freestanding miniscrews, were examined in the study. A variety of orthodontic loads were applied. The majority of implants were placed in the posterior maxilla (104/140), and the next most common location was the posterior mandible (34/140). Results: A cumulative survival rate of 89% (125/140) was found by Kaplan-Meier analysis. There was no significant difference in the survival rate between miniplates and freestanding miniscrews, but miniplates were used in more hazardous situations. The Cox proportional-hazards regression model identified anatomic location and peri-implant soft tissue character as 2 independent prognostic indicators. The estimated relative risk of implant failure in the posterior mandible was 1.101 (95% confidence interval, 0.942 to 1.301; P = .046). The risk ratio of failure for implants surrounded by nonkeratinized mucosa was 1.117 (95% confidence interval, 0.899 to 1.405; P = .026). Discussion and Conclusion: The results confirmed the effectiveness of orthodontic mini-implants, but in certain situations adjustment of the treatment plan or modifications in the technique of implant placement may lead to improved success rates. INT J ORAL MAXILLOFAC IMPLANTS 2004;19:100‐106

Nonparametrics Statistical Methods Based On Ranks

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Failure rates and associated risk factors of orthodontic miniscrew implants: A meta-analysis

Abstract: Introduction Risk factors concerning orthodontic miniscrew implants have not been adequately assessed. In this systematic review, we summarize the knowledge from published clinical trials regarding the failure rates of miniscrew implants used for orthodontic anchorage purposes and identify the factors that possibly affect them. Methods Nineteen electronic databases and reference lists of included studies were searched up to February 2011, with no restrictions. Only randomized controlled trials, prospective controlled trials, and prospective cohort studies were included. Study selection and data extraction were performed twice. Failure event rates, relative risks, and the corresponding 95% confidence intervals were calculated. The random-effects model was used to assess each factor's impact. Subgroup and meta-regression analyses were also implemented. Results Fifty-two studies were included for the overall miniscrew implant failure rate and 30 studies for the investigation of risk factors. From the 4987 miniscrew implants used in 2281 patients, the overall failure rate was 13.5% (95% confidence interval, 11.5-15.8). Failures of miniscrew implants were not associated with patient sex or age and miniscrew implant insertion side, whereas they were significantly associated with jaw of insertion. Certain trends were identified through exploratory analysis; however, because of the small number of original studies, no definite conclusions could be drawn. Conclusions Orthodontic miniscrew implants have a modest small mean failure rate, indicating their usefulness in clinical practice. Although many factors seem to affect their failure rates, the majority of them still need additional evidence to support any possible associations.

Cone-beam CT in paediatric dentistry: DIMITRA project position statement.

Abstract: DIMITRA (dentomaxillofacial paediatric imaging: an investigation towards low-dose radiation induced risks) is a European multicenter and multidisciplinary project focused on optimizing cone-beam CT exposures for children and adolescents. With increasing use of cone-beam CT for dentomaxillofacial diagnostics, concern arises regarding radiation risks associated with this imaging modality, especially for children. Research evidence concerning cone-beam CT indications in children remains limited, while reports mention inconsistent recommendations for dose reduction. Furthermore, there is no paper using the combined and integrated information on the required indication-oriented image quality and the related patient dose levels. In this paper, therefore, the authors initiate an integrated approach based on current evidence regarding image quality and dose, together with the expertise of DIMITRA’s members searching for a state of the art. The aim of this DIMITRA position statement is to provide indication-oriented and patient-specific recommendations regarding the main cone-beam CT applications in the pediatric field. The authors will review this position statement document when results regarding multidisciplinary approaches evolve, in a period of 5 years or earlier.

Comparison of intrusion effects on maxillary incisors among mini implant anchorage, j-hook headgear and utility arch.

Abstract: Background: Intrusion of maxillary incisors is one of the most important and difficult tooth movements to achieve as a part of orthodontic therapy. A variety of techniques were used in the past to intrude the maxillary incisors before the emergence of mini implants in Orthodontics. Mini implants are temporary anchorage devices used to produce various tooth movements. The research was carried out to evaluate and compare the efficiency of producing intrusion of maxillary incisors using mini implants, utility arch and j- hook headgear. Materials and Methods: The study was conducted on 30 subjects divided into 3 Groups equally. Group 1- mini implant anchorage, Group 2 - j- hooks headgear and Group 3- utility arch were used for intrusion of the maxillary incisors. Conventional lateral cephalograms were taken before treatment and at the end of intrusion. Five cephalometric parameters were used to measure the amount of intrusion attained in each Group. Intra Group comparisons were done using student t-test and inter Group comparisons were done using ANOVA The duration of intrusion was four months in all the three Groups. Results: In Group 1 the mean average intrusion attained was 2.1 mm, the mean average intrusion attained in Group 2 was 0.7 mm, and the mean average intrusion achieved in Group 3 was 1.4 mm with a side effect of 0.75 mm of molar extrusion. Conclusion: Although, both mini implants and utility arch can be used to attain significant amounts of incisor intrusion but using mini implants will produce true intrusion without any other side effects.