Rohit Khanna

Risk factors and management of white spot lesions in orthodontics

The formation of white spot lesions or enamel demineralization around fixed orthodontic attachments is a common complication during and following fixed orthodontic treatment, which mars the result of a successfully completed case. This article is a contemporary review of the risk factors, preventive methods and fate of these orthodontics scars. The importance of excellent oral hygiene practice during fixed orthodontic treatment must be explained. Preventive programs must be emphasized to all orthodontic patients. Suggestions are offered in the literature for ways to prevent this condition from manifesting itself.

Nasomaxillary complex in size, position and orientation in surgically treated and untreated individuals with cleft lip and palate: A cephalometric overview

Background: This cross-sectional retrospective cephalometric study was designed to clarify whether the maxillary deficiency seen in surgically treated individuals with non-syndromic complete unilateral cleft lip and palate (UCLP) is due to inherent growth potential or iatrogenicity. Materials and Methods: 72 adult individuals were randomly selected in the age range of 12-20 years, and were divided into two groups. Group I had 47 untreated individuals. Group II consisted of 25 surgically treated individuals. Lateral and frontal cephalograms of the selected individuals were taken and analysed using Nemoceph software. Results: Group II showed a marked reduction in the cranial base angle, maxillary base length, anterior and posterior maxillary positions, palatal plane angle, maxillary width, maxillary height, occlusal plane height, nasal width and nasal height. Conclusion: Surgical intervention does interfere with growth in the facial region. This could be attributed to the scar tissue in lip and palate region, which has a restraining effect on growth in the facial region. These altered functional matrices play a significant role in determining the growth of facial structures.

Release of nickel and chromium ions in the saliva of patients with fixed orthodontic appliance: An in-vivo study

Introduction: Various components of fixed orthodontic appliances are continuously interacting with saliva and other fluids in the mouth releasing various metal ions including nickel and chromium that can cause damaging effects if their concentration exceeds above the toxic dose. Aim: To determine and compare the level of nickel and chromium in the saliva of patients undergoing fixed orthodontic treatment at different time periods. Materials and Methods: The sample of saliva of 13 patients was taken at different time periods that is: Group 1 (before appliance placement), Group II, III, and IV (after 1-week, 1-month, and 3 months of appliance placement respectively). The fixed appliance comprised of brackets, bands, buccal tubes, lingual sheath, transpalatal arch and wires composed of Ni-Ti and stainless steel. The level of ions was determined using graphite furnace atomic absorption spectro-photometry. The data thus obtained were statistically analyzed using SPSS Statistical Analysis Software (Version 15.0). Results: Level of nickel and chromium in saliva was highest in Group II and lowest in Groups I for both the ions. On comparison among different Groups, it was statistically significant for all the groups (<0.001) except between Group III and Group IV. Conclusion: The release of nickel and chromium was maximum at 1-week and then the level gradually declined. These values were well below the toxic dose of these ions. The results should be viewed with caution in subjects with Ni hypersensitivity.

Role of buccal corridor in smile esthetics and its correlation with underlying skeletal and dental structures.

PURPOSE This study was designed to evaluate the buccal corridor in smile esthetics and to correlate it with underlying hard tissues. MATERIALS AND METHODS Posed smiling frontal photographs, digital posterior-anterior (PA) cephalograms, and study models of 25 males and 25 females in age range of 18-25 years were taken. Photographs were evaluated for smile esthetics by eight orthodontists, eight plastic surgeons, eight beauticians and eight lay people to group them into three groups with least attractive, average and attractive smile and buccal corridor width was measured. Digital PA cephalograms were transferred on Nemo-tech software for frontal facial analysis. Intercanine and intermolar widths were measured on upper study model with the help of a digital calliper. RESULTS The buccal corridor width was least in attractive smile group and maximum in least attractive smile group. The buccal corridor width had a negligible correlation with hard tissues and a mild to moderate inverse correlation with intercanine and intermolar widths within the groups. CONCLUSION As the amount of buccal corridor display was increased, smiling images were scored less attractive by the evaluators. The buccal corridor is not influenced by underlying skeletal hard tissues but have mild to moderate inverse correlation with the intercanine and intermolar width.

A new proposed regression equation for mixed dentition analysis using the sum of permanent mandibular four incisors and first molar as a predictor of width of unerupted canine and premolars in a sample of North Indian population

Objective: The objective of this study was to establish a new regression equation for North Indian and to compare and correlate the predicted width of unerupted canine and premolars obtained from the proposed regression equation of the present study in the North Indian population sample, Moyers prediction table and also from Melgaco regression equation with the actual width; in order to check the applicability of various methods of mixed dentition analysis for the North Indian population. Materials and Methods: The sample consisted of 200 dental casts obtained from the North Indian patients and students which consists of 100 males and 100 females with the average age of 20.12 ± 4.70 years for males and 19.54 ± 3.16 years for females. Mesiodistal tooth widths of mandibular arch from permanent right first molar to left first molar were measured with an electronic digital caliper. Student t-test was used for comparison and Pearsons correlation coefficient was used to correlate the actual sum and the predicted width of the permanent mandibular canines and premolars obtained from various methods. Results: The difference between the actual and predicted width was statistically insignificant using the regression equation obtained for the North Indian sample population (correlation r = 0.78) in contrast to the significant difference with predicted width obtained from Melgaco equation (r = 0.61) and Moyers prediction table (r = 0.42). Conclusions: A new proposed regression equation for the North Indian population was established. Amongst the three regression equations devised, the proposed regression equation formulated in the present study; gave the most accurate results confirming racial variation in tooth size. This method is considered as an easy and practical way to predict the size of unerupted canines and premolars.

A case study of primary malignancy of buccal mucosa using proton HR-MAS NMR spectroscopy on tissue specimens

The diagnosis and confirmation of oral SCC (squamous cell carcinoma) is still dependent on histopathology report in spite of development of radiological investigations. It is, thus important to understand the underlying molecular mechanisms and how the alterations in metabolic pathways effect the tumor development and progression. The simultaneous and comprehensive information about the presence and absence of small molecule metabolites and their relative concentrations has been provided by 1H HR-MAS NMR spectroscopy on tissue specimens. In this paper a unique case study was presented in order to correlate histological and NMR spectroscopic findings. The patients initially lesion was found to be non-malignant in nature based on histological findings but its periodic localized recurrence even after laser ablation prompted us to perform HR-MAS based analysis and its role in identifying the metabolic alterations in known pathways occurring during its progressions. Thus it was confirmed after analysis that HR-MAS NMR can also be used as an analytical tool which is reliable in order to distinguish between malignant and non-malignant tissues, in combination with histopathology.

Dimensional and volumetric analysis of the oropharyngeal region in obstructive sleep apnea patients: A cone beam computed tomography study

Background: Obstructive Sleep Apnea (OSA) is a potentially life-threatening condition in which there is a periodic cessation of breathing (for 10 sec or longer) that occurs during sleep in the presence of inspiratory effort. The aim of the study was to assess volumetric and dimensional differences between OSA patients and normal individuals in the upright posture. Material and Method: The present study was conducted on CBCT scans of 32 patients who were divided into two groups -Group I (control group) and Group II (OSA subjects). Group I consisted of 16 patients with normal airway with ESS score from 2 to 10, STOP BANG Questionnaire score of <3 and who had undergone CBCT for various diagnostic reasons. Group II had patients with ESS score >10, STOP BANG Questionnaire score of > 3, AHI index >5. Linear and angular parameters, volume and minimum cross-section area (MCA) of oropharyngeal airway, anteroposterior length and lateral width at MCA was compared amongst the groups. Results: The oropharyngeal volume, MCA, and the anteroposterior and lateral width of the airway at MCA of the OSA subjects was significantly lesser than that of normal subjects. The length of both soft palate and tongue was significantly more in Group II. The angle between the nasopharyngeal airway and the oropharyngeal airway was significantly more obtuse in Group II. Conclusion: The reduction in oropharyngeal volume in OSA patients could be attributed to different anatomical and pathophysiological factors that were corroborated with the findings of the present study.

Ortho-surgical management of skeletal Class III malocclusion.

Class III malocclusions are considered to be one of the most difficult problems to treat. Establishment of the treatment plan is based on the efficacy and thoughtful application by the clinician and easy acceptance by the patient. We are presenting a case report of an adult male patient with skeletal Class III malocclusion who was treated by orthosurgical approach in Department of Orthodontics in collaboration with Department of Oral and Maxillofacial Surgery. The treatment was complete with a positive overbite and acceptable occlusion and satisfactory facial esthetics using a combination approach.

Arnett's Soft-tissue Cephalometric Analysis Norms for the North Indian Population: A Cephalometric Study

Objective: To determine the soft-tissue cephalometric norms as per Arnett’s analysis for male and female subjects of North Indian population and to compare these cephalometric norms with Arnett’s norms for Caucasian population. Materials and methods: Frontal and profile photographs of 150 subjects with normal occlusion and pleasing profile were rated by a panel of judges, from which 50-male and 50-female subjects were selected and their lateral cephalograms were taken for the present study. Arnett’s soft-tissue cephalometric analysis (STCA) was done on these cephalograms using Nemotech cephalometric software. Mean values of various parameters were obtained and these values were compared to Arnett’s norms for Caucasian population using Student t-test. These values were also compared among males and females of North Indian population. Results: High overjet, thicker soft-tissue, less facial length, retruded lower face and midface and convex profile were observed in the North Indian population as compared to Caucasian population. Males of North Indian population have thicker soft-tissue structures, more acute nasolabial angle, longer faces and more deep-set facial structures than females whereas females have greater interlabial gap and maxillary incisor exposure. Conclusion: Statistically significant differences in certain parameters were found between North Indian population and Caucasian population and also between males and females of North Indian population.

Sequencing of the interferon regulatory factor 6 (IRF6) gene and correlation to its phenotypes in familial non-syndromic cleft lip and palate in North Indian population

BackgroundThe incidence of orofacial clefting varies depending upon geographical location, ethnicity, sex and even socioeconomic status. The study aimed to test the contribution of interferon regulatory factor 6 (IRF6) gene allelic variation to the incidence of non-syndromic cleft lip and/or cleft palate (CL/P) from the population of North India.MethodsPatients from 12 North Indian families with non-syndromic cleft lip with or without cleft palate (NSCL/P) with at least two members affected were clinically evaluated and tested. DNA was extracted from the blood, and three exonic part of the IRF6 gene (exons 2, 5 and 7) were amplified by PCR. Direct sequencing was performed by PCR product, and sequencing results were compared with the reference DNA sequence of the IRF6 gene.ResultsThree SNPs (rs861019, rs2013162 and rs2235372) in 4 out of 12 families were observed. SNP rs861019 was detected in family no. 4 (F4) around exon 2, SNP 2013162 was detected in family no. 10 (F10) and SNP 2235372 was detected in family nos. 5 and 9 (F5 and F9).ConclusionsThis study demonstrates that the three SNPs within the IRF6 gene are associated with NSCL/P, suggesting IRF6 gene sequence variability and variation in this gene, providing first genetic clue to the NSCL/P phenotype in North Indian families. This is our initial step to demonstrate the involvement of the IRF6 gene in NSCL/P patients in North India. Further extensive study and statistical analysis are needed to validate our result.Level of Evidence: Level IV, diagnostic study.