Effect of green tea and sodium ascorbate on the shear bond strength of orthodontic brackets bonded on bleached enamel: An in-vitro study.

OBJECTIVE: The primary objective was to assess and compare the shear bond strength of orthodontic brackets bonded on bleached enamel with and without using an anti-oxidizing agent.The secondary objective was to compare the shear bond strength of brackets between the groups with anti-oxidant application along with immediate bonding and that of delayed bonding without any anti-oxidant treatment, on bleached teeth. MATERIALS & METHODS: 75 premolars were collected and thereafter randomly distributed into the 5 groups. Group 1 to 4 had undergone bleaching with 10% carbamide peroxide and group 5 was control. Group 1 was bonded immediately after bleaching while bonding was delayed in group 4 for a period of 1 week. Groups 2 and 3 received the anti-oxidant treatment with 10% sodium ascorbate gel and 10% green tea gel respectively. Hounsfield universal testing machine was used for testing the shear bond strength. RESULTS: For group 1, the shear bond strength was significantly lower (mean 4.9 MPa) than group 5 (mean 12.5 MPa). The significant differences were observed on comparing the shear bond strength of antioxidant-treated and delayed bonding groups with control (p < 0.05). Mean shear bond strength in groups 2, 3 and 4 were 7.5 MPa, 9.6 MPa and 5.8 MPa respectively. CONCLUSION: The bond strength of brackets reduces immediately after the bleaching procedure. The bond strength can be reversed either by delaying the bonding for a period of 1 week or by using the anti-oxidizing agents but it is not up to the level of unbleached enamel.

Stability of Vertical, Horizontal and Angular Parameters Following Superior Repositioning of Maxilla by Le Fort I Osteotomy: A Cephalometric Study.

INTRODUCTION: The restoration of normal jaw function, optimal facial aesthetics and long term stability are the goals of any orthognathic surgical procedures. During the last two decades, several cephalometric investigations have been reported on the skeletal changes following maxillary surgical procedures. The stability following LeFort I osteotomy and maxillary superior repositioning of the maxilla has not been studied extensively. AIM: This study was aimed at determining the surgical changes brought about by superior repositioning of the maxilla by Le Fort I osteotomy and evaluate the stability of the surgical procedure one year following surgery. MATERIALS AND METHODS: Presurgical and postsurgical and one year post surgical lateral cephalograms of 10 adult patients (age group - 17 to 40 years, with a mean age of 22.2 years) who had been treated successfully by maxillary Le-Fort I osteotomy and impaction were obtained. The lateral cephalograms were grouped into three categories: T1- Presurgical, T2- Postsurgical, T3- One year postsurgical. Comparisons were made between T1-T2 and T2-T3 to assess the changes following surgery and to evaluate the stability, one year following the surgery using 5 horizontal, 5 vertical linear and 2 angular measurement. Statistical analysis was done with SPSS (Version 17). Results were expressed as mean±standard deviation. A paired t-test was used to analyze the paired observations. RESULTS: The difference between T1 and T2 values of vertical changes showed that they were statistically highly significant whereas from T2 to T3 they were insignificant. The difference between T1 and T2 values of all the horizontal changes showed that they were statistically significant whereas True Vertical Line (TVL) to point Anterior Nasal Spine (ANS) was not statistically significant. The horizontal changes from T2 to T3 were statistically not significant whereas TVL to point Incisal edge of upper incisor (Is) was statistically significant. The angular changes from T1 to T2, T2 to T3 were statistically not significant. CONCLUSION: There was a significant reduction in the facial height and significant anterior movement of maxilla after surgery. Even after one year of surgery, negligible amount of relapse was recorded except at the incisors.

Incidence of Tooth Size Discrepancy in Different Groups of Malocclusion and its Relation to Extraction.

BACKGROUND: For proper intercuspation, the teeth must be proportional in size. If teeth are mismatched, with unusually large teeth in one arch compared to the other, then an ideal occlusion cannot be attained. This study has been done to determine the prevalence of tooth size discrepancies among orthodontic patients in general and also between different malocclusion groups, sex, and to analyze the change in the degree of severity in Bolton discrepancy before and after the hypothetical premolar extraction. METHODS: The study was carried out on randomly collected 100 pre-treatment dental casts. Tooth size analyses were performed on these pre-treatment models and Mesio distal tooth size ratios were measured as described by Bolton before and after various patterns of hypothetical extraction. RESULT: The results were statistically evaluated using ANOVA and paired samples t-test. 5 out of 100 patients are seen with severe Bolton discrepancy with Bolton values (BV) ranging above and below 2 standard deviation. Statistically insignificant difference is seen between males and females and also between various groups of malocclusion. The difference between the pre-treatment and post extraction BV was found statistically significant for the first premolar extraction and insignificant for others. CONCLUSION: The results of this study indicate a new point of view to the question of which teeth to extract when evaluated for tooth size aspect only.

Congenital infiltrating lipomatosis of face: case report and review of literature.

Hemifacial hyperplasia is a rare condition causing unilateral enlargement of all tissues. We report a case of progressive facial asymmetry caused by congenital infiltrating lipomatosis of the face in a 6-year-old boy. The approach to diagnosis in our case is discussed along with a review of cases reported in the literature.

Dental arch changes associated with rapid maxillary expansion: A retrospective model analysis study.

INTRODUCTION: Transverse deficiency of the maxilla is a common clinical problem in orthodontics and dentofacial orthopedics. Transverse maxillary deficiency, isolated or associated with other dentofacial deformities, results in esthetic and functional impairment giving rise to several clinical manifestations such as asymmetrical facial growth, positional and functional mandibular deviations, altered dentofacial esthetics, adverse periodontal responses, unstable dental tipping, and other functional problems. Orthopedic maxillary expansion is the preferred treatment approach to increase the maxillary transverse dimension in young patients by splitting of the mid palatal suture. This orthopedic procedure has lately been subject of renewed interest in orthodontic treatment mechanics because of its potential for increasing arch perimeter to alleviate crowding in the maxillary arch without adversely affecting facial profile. Hence, the present investigation was conducted to establish a correlation between transverse expansion and changes in the arch perimeter, arch width and arch length. METHODS: For this purpose, 10 subjects (five males, five females) were selected who had been treated by rapid maxillary expansion (RME) using hyrax rapid palatal expander followed by fixed mechanotherapy (PEA). Pretreatment (T1), postexpansion (T2), and posttreatment (T3) dental models were compared for dental changes brought about by RME treatment and its stability at the end of fixed mechanotherapy. After model measurements were made, the changes between T1-T2, T2-T3 and T1-T3 were determined for each patient. The mean difference between T1-T2, T2-T3 and T1-T3 were compared to assess the effects of RME on dental arch measurements. Results are expressed as mean ± standard deviation and are compared by repeated measures analysis of variance followed by a post-hoc test. Arch perimeter changes are correlated with changes in arch widths at the canine, premolar and molar regions. RESULTS: The intercanine arch width increased by 2.9 mm, inter first premolar width increased by 3.2 mm, inter second premolar width increased by 4.6 mm, intermolar width increased by 4.4 mm, arch perimeter increased by 3.2 mm, arch length decreased by 1.8 mm from pretreatment to posttreatment. There is a strong positive correlation of arch perimeter with intercanine width (r (2) = 0.99), interpremolar width (r (2) = 0.99) and intermolar width (r (2) = 0.98), indicating that there is a significant increase in arch perimeter with increase in arch width at the canine, premolars and molar regions. CONCLUSION: Findings of this study demonstrate that there was a significant increase in the intercanine, inter first premolar, inter second premolar intermolar arch width and arch perimeter from pretreatment to postexpansion, which was stable at the end of fixed mechanotherapy (PEA). There was a nonsignificant decrease in arch length from pretreatment to postexpansion that further decreased nonsignificantly from postexpansion to posttreatment.

Evaluation of dental age and associated developmental anomalies in subjects with impacted mandibular canines.

OBJECTIVES: To assess the null hypothesis that there is no difference in the rate of dental development and the occurrence of selected developmental anomalies related to shape, number, structure, and position of teeth between subjects with impacted mandibular canines and those with normally erupted canines. MATERIALS AND METHODS: Pretreatment records of 42 subjects diagnosed with mandibular canines impaction (impaction group: IG) were compared with those of 84 subjects serving as a control reference sample (control group: CG). Independent t-tests were used to compare mean dental ages between the groups. Intergroup differences in distribution of subjects based on the rate of dental development and occurrence of selected dental anomalies were assessed using χ(2) tests. Odds of late, normal, and early developers and various categories of developmental anomalies between the IG and the CG were evaluated in terms of odds ratios. RESULTS: Mean dental age for the IG was lower than that for the CG in general. Specifically, this was true for girls (P < .05). Differences in the distribution of the subjects based on the rate of dental development and occurrence of positional anomalies also reached statistical significance (P < .05). The IG showed a higher frequency of late developers and positional anomalies compared with controls (odds ratios 3.00 and 2.82, respectively; P < .05). CONCLUSIONS: The null hypothesis was rejected. We identified close association of female subjects in the IG with retarded dental development compared with the female orthodontic patients. Increased frequency of positional developmental anomalies was also remarkable in the IG.

Long term stability and relapse following mandibular advancement and mandibular setback surgeries: a cephalometric study.

BACKGROUND: The aim was to evaluate the long-term hard and soft tissue changes following mandibular advancement and setback surgeries. MATERIALS AND METHODS: A total of 16 subjects each were selected who underwent bilateral sagittal split osteotomy mandibular advancement and mandibular setback groups. Pre-surgical (T1), immediate post-surgical (T2) and long-term post-surgical (T3) cephalograms were compared for hard and soft tissue changes. After cephalometric measurements, the quantity of changes between T1-T2 and T1-T3 were determined for each patient. The mean difference between T1-T2 and T1-T3 was compared with assess the long-term changes and stability. RESULTS: In mandibular advancement the mean difference between immediate post-surgical and long term post-surgical is 7%, which accounts for a relapse of 7%. In mandibular setback, the mean difference between immediate post-surgical and long-term post-surgical is 29%, which accounts for a relapse of 29%. CONCLUSION: Mandibular advancement remained stable over the long period when compared to mandibular setback.

Permanent mandibular canine(s) impaction: expansion of our understanding.

INTRODUCTION: Eruption disturbances, tooth size and specific malocclusions are known to be genetically influenced. The clinical association between these traits may indicate common genetic controls. OBJECTIVES: A cross-sectional clinical study was designed to test the null hypothesis that the maximum mesiodistal crown diameter (MMD) of maxillary and mandibular central and lateral incisors and the prevalence of various classes of incisor relationships (Class I, II/1, II/2 and III) do not differ between the subjects with and without permanent mandibular canine(s) impaction. METHODS: Dental models of 43 subjects diagnosed with mandibular canine(s) impaction (Impaction Group - IG) were compared with those of 86 subjects of a control reference sample (Control Group - CG). Independent t-test and chi-square tests were used to determine the association between mandibular canine(s) impaction and the MMD of the incisors and the incisor relationship, respectively. The likelihood of various incisor relationships between the IG and CG were evaluated according to odds ratios. RESULTS: A fourfold increase (p < 0.0001) in the overall frequency of Class II/2 incisor relationship was observed in the IG when compared to controls. CONCLUSIONS: The null hypothesis was rejected. Subjects with mandibular canine(s) impaction appeared to be characterised with wider incisors and a remarkably high rate of Class II/2 malocclusion. This information assists the understanding of genetically controlled dental anomalies, which are likely to coexist with mandibular canine(s) impaction.

Comparison of anchorage loss following initial leveling and aligning using ROTH and MBT Prescription - A clinical prospective study.

BACKGROUND: To evaluate the amount and percentage of anchor loss after initial leveling and aligning using a ROTH and MBT prescription. MATERIALS & METHODS: Pre and post alignment lateral cephalograms & dental casts of 10 ROTH & 10 MBT patients. RESULTS: In the study, it was found that the amount of anchor loss is greater in the ROTH group than the MBT group. This could be due to the increased anterior tip in the ROTH prescription, compared to MBT. The total anterior tip in ROTH is 270 and in MBT is 200. The additional tip of 70 in ROTH prescription itself would have resulted in forward thrust of the anteriors. CONCLUSION: The use of laceback and cinchbacks creates a statistically and clinically significant increase in the anchorage loss specifically when the posterior anchorage is not enhanced. In this study TPA was not used but studies have shown that passive TPA has almost no effect on the clinician's need to preserve anchorage in the correction of malocclusion. On the other hand, the TPA is an excellent way to prevent molar rotation and maintain the original vertical and transverse dimension when desired. How to cite the article: Rajesh M, Kishore MS, Shetty KS. Comparison of anchorage loss following initial leveling and aligning using ROTH and MBT Prescription - A clinical prospective study. J Int Oral Health 2014;6(2):16-21.

A simple technique for the direct bonding of a lingual retainer: a clinical hint.

The direct bonding of a fixed wire retainer often poses clinical difficulties. While there are several possible techniques, the present paper describes a simple method employing a ball clasp (S handle) to assist in the stabilisation of the wire to be attached. The advantages and disadvantages are indicated.

Growth modulation using functional appliances--cephalometric predictors of successful response.

AIM: The aim of this study was to determine any skeletal morphologic features evident on a pretreatment lateral cephalogram that may be used to predict improvement in the sagittal relationship during functional appliance therapy in Class II patients and compare changes between cases with and without a favorable response to growth modulation. METHOD: Pretreatment and postfunctional lateral cephalograms were analyzed, and the change in the ANB angle was used to determine the skeletal response to treatment with a functional appliance. Based on the change in the ANB angle, the patients were divided into two groups of 12 patients each. Comparisons were made between the mean pretreatment (T1) cephalometric parameters of group I (skeletal) and group II (nonskeletal) to assess any pretreatment parameters that were significantly different between the groups. Changes due to functional appliance therapy from the pretreatment (T1) to postfunctional (T2) stage was measured as T2-T1 in both groups. The mean changes seen in group I and group II were then compared to assess the difference between changes brought about by growth modulation using functional appliances. Comparative statistical analysis of the data was done using one-way analysis of variance F test. RESULTS AND CONCLUSION: This study showed that not all cases respond favorably to growth modulation. The pretreatment parameters that correlated to a favorable response were low mandibular plane angle, low basal plane angle, and a high Jarabak ratio. In those cases that responded favorably, the changes seen were an increase in Co-Go (ramus height), decrease in overjet, increase in SNB, and increase in the Jarabak ratio.

Study of stress distribution and displacement of various craniofacial structures following application of transverse orthopedic forces--a three-dimensional FEM study.

The purpose of this study was to analyze the stress distribution patterns within the craniofacial complex during rapid maxillary expansion. Therefore, a finite element model of a young human skull was generated using data from computerized tomographic scans of a dried skull. The model was then strained to a state of maxillary expansion simulating the clinical situation. The three-dimensional pattern of displacement and stress distribution was then analyzed. Maximum lateral displacement was 5.313 mm at the region of upper central incisors. The inferior parts of the pterygoid plates were also markedly displaced laterally. But there was minimum displacement of the pterygoid plates approximating the cranial base. Maximum forward displacement was 1.077 mm and was seen at the region of the anteroinferior border of the nasal septum. In the vertical plane, the midline structures experienced a downward displacement. Even the ANS and point A moved downward. The findings of this study provide some additional explanation of the concept of correlation between the areas of increased cellular activity and the areas of dissipation of heavy orthopedic forces. Therefore, the reason for the occurrence of sensation of pressure at various craniofacial regions, reported by the patients undergoing maxillary expansion could be correlated to areas of high concentration of stresses as seen in this study. Additionally, the expansive forces are not restricted to the intermaxillary suture alone but are also distributed to the sphenoid and zygomatic bones and other associated structures.