Gulshan Kumar Singh

Dynamics of a smile in different age groups.

OBJECTIVEnTo evaluate smile in different age groups and to detect gender differences in smile.nnnMATERIALS AND METHODSnDigital videographic records of 241 randomly selected subjects were obtained for smile analysis. The subjects were divided into four groups by age (15-20 years, 21-30 years, 31-40 years, and 41-50 years). Each group was further subdivided by gender. After 41 subjects were excluded, the smile dimensions of 200 subjects were analyzed by two-way multivariate analysis of variance (MANOVA) with Duncans multiple range post hoc test.nnnRESULTSnAll dynamic measurements (change in upper lip length, upper lip thickness, commissure height, and intercommissural width from rest to smile) decreased with age in both males and females. Changes in upper lip length and commissure height on smiling were greater in males as compared with females of the same age groups. Changes in intercommissural width on smiling were greater in females as compared with males in all age groups.nnnCONCLUSIONnSmile changes with increase in age, and the changes differ between males and females. Females had a wider smile as compared with males of similar age groups.

The effect of central incisor's root proximity to the cortical plate and apical root resorption in extraction and non-extraction treatment.

Aims: The present study was conducted to investigate the relevance of cortical plate proximity of maxillary central incisor root, maxillary alveolar bone width, and the apical root resorption in extraction and non-extraction orthodontically treated cases. Further, the correlation between the apical root resorption and the various parameters was investigated. Materials and Methods: A total of 80 lateral head cephalographs, 40 pre-treatment and 40 post-treatment, of orthodontic subjects with a mean age of 15 years treated with fixed standard edgewise appliance were obtained. All subjects were divided into two groups as extraction and non-extraction cases. Twelve linear and three angular parameters were measured and evaluated. The paired “t”-test, Pearsons correlation coefficient, and the stepwise regression analysis were done to test the relationship between the apical root resorption and the various parameters. Results and Conclusions: The study revealed slightly greater amount of apical root resorption in extraction subjects as compared to non-extraction subjects. However, no statistically significant difference was found between the two treatment modalities. In extraction subjects, the apical root resorption was directly proportional to the pre-treatment length of maxillary central incisor and inversely proportional to the root width in apical one-third region, though there was a weak correlation. In non-extraction subjects, the pre-treatment anteroposterior position of the root apex of maxillary central incisor in the alveolar bone, in combination with its root width in the apical one-third region formed the predictive factors for the variance in the amount of the apical root resorption, though there was a weak correlation. Furthermore, the changes in the alveolar widths at the root apex and mid-root region were considered as predictive factors for the amount of apical root resorption during extraction and non-extraction treatment, respectively.

A comparative study of frictional resistance during simulated canine retraction on typodont model.

Objectives: Frictional resistance is an important counterforce to orthodontic tooth movement during sliding mechanics. This study was carried out to evaluate the effect of different bracket-archwire-ligation combinations on “resistance to sliding” during simulated canine retraction on typodont model. Materials and Methods: the frictional resistance was tested between three modern orthodontic brackets-stainless steel, ceramic, and ceramic with metal slot (0.022-inch), and seven different archwires (0.019 × 0.025-inch)-stainless steel, nickel-titanium, Teflon coated stainless steel, stainless steel with the reverse curve of spee (RCS), Teflon coated stainless steel with RCS, Teflon coated nickel-titanium and nickel-titanium with RCS ligated with stainless steel ligature wire and regular clear elastomeric modules. All tests were carried out in a dry state on an Instron universal testing machine (crosshead speed: 0.5 mm/min). 10 measurements were made from each bracket-archwire-ligature combinations. Results: The highest mean frictional resistance was found in ceramic brackets with nickel-titanium RCS archwire ligated with elastomeric modules while minimum frictional resistance was found in stainless steel brackets with Teflon coated stainless steel archwire ligated with stainless steel ligature. Metal slot ceramic brackets generated significantly lower frictional forces than ceramic brackets, but higher values than stainless steel brackets. Teflon coated archwires shows highly significant reduction of the frictional resistance than their corresponding uncoated archwires. Archwires with RCS had the higher frictional resistance than normal counterpart archwires. Conclusion: Ceramic brackets with metal slot and Teflon coated SS archwires seem to be a good alternative to conventional stainless steel brackets and archwires in space closure with sliding mechanics in patients with esthetic demands.

A rare syndrome with unusual dental findings: Oculo-facio-cardio-dental syndrome.

Radiculomegaly of a tooth is a rare condition. When it is associated with other dental abnormalities, facial dysmorphism and congenital cataracts, the condition is named as oculofaciocardiodental (OFCD) syndrome. This is an X-linked dominant trait, reported only in women, suggesting that it is lethal in males. The most consistent and pathognomic dental finding of OFCD is radiculomegaly (extremely long roots), particularly of the canines and occasionally of other teeth including premolars and incisors, which can easily be diagnosed on dental panoramic radiographs by a dentist or an orthodontist. Till date, 21 cases have been reported worldwide. The aim of this report is to present a new case of a 24 year old female affected by this syndrome and to evaluate it from a dental perspective to call the attention of dentists to this rare anomaly.

Relationship between Dental Arch Dimensions and Vertical Facial Morphology in Class I Subjects

Introduction: A well-balanced face has its good proportions in all three dimensions of space, i.e. transverse, sagittal and vertical. The vertical proportions of the face are important in determining the esthetics and harmony of the face. The objectives of this study were to evaluate the relationship between dental arch dimensions and the vertical facial pattern determined by the Jarabak ratio, and to examine the differences in dental arch dimensions between male and female untreated adults. Materials and methods: Lateral cephalograms and study models were obtained from 90 untreated subjects (45 males, 45 females) between 17 and 24 years of age with no crossbite, no/minimal crowding and spacing. The Jarabak ratio (posterior facial height/anterior facial height) was measured on cephalograms of each patient. Study models were used to obtain comprehensive dental measurements, including maxillary and mandibular cumulative mesiodistal width, intercanine, first interpremolar and first intermolar widths as well as arch perimeter, arch length, overbite, palatal height and curve of Spee. Results: The results showed that, for both males and females, there was a trend that as vertical facial height increased, arch width, arch perimeter and overbite decreased but palatal height and curve of Spee increased and males have significantly larger arch dimensions than those of females. Conclusion: It was concluded that dental arch dimensions were associated with facial vertical morphology and gender. Thus, using individualized archwires according to each patient’s pretreatment arch form and width is suggested during orthodontic treatment.

Removable partial denture with molar uprighting spring: an innovative hybrid appliance.

PATIENTnA 45-year-old female patient with need of fixed replacement of her missing teeth which were lost long time before. Posterior teeth were severally tipped bilaterally in the edentulous space. Hybrid removable partial denture with molar uprighting spring was fabricated for molar uprighting on both side tilted molars. After 3 month and 15 days of treatment with hybrid appliance the molar abutment were uprighted for fabrication of fixed partial dentures.nnnDISCUSSIONnThe objective in molar uprighting is ideal positioning of the molar which will eventually become an abutment tooth for a fixed prosthesis. The ideal position will provide an optimal periodontal environment for the molar. The prosthodontic advantages of molar uprighting via distal tipping include an improved line-of-draw if a FPD is being constructed. Concept of designing of appliances was based on our basic knowledge of forces for uprighting the tooth along with maintaining the function during the treatment period. Another advantage of this appliance was that it prevented supra eruption of opposing teeth during the period when the molar was being uprighted.nnnCONCLUSIONnUprighting of tilted molar is extremely beneficial for long term success of fixed denture prosthesis by using hybrid appliances in very short period of treatment without hampering the function of the patient during the treatment period which is very economical as well.

Evaluation of facial divine proportion in North Indian Population

Objective: To evaluate the facial divine proportion and its relationship with facial attractiveness in North Indian population. Materials and Methods: For evaluation of various facial proportions, standardized frontal facial photographs of total 300 subjects between 18 and 30 years of age were obtained. Black and white copies of these photographs were presented in front of an evaluation jury for assigning scores of facial attractiveness and finally 130 attractive subjects were selected. These subjects were divided into two groups, Group I (attractive females n = 65) and Group II (attractive males n = 65) and they were further analyzed for various parameters of facial proportions. Unpaired Student′s t-test was used to compare both groups. Results: Group I showed that five of seven vertical facial proportions were close to divine proportion (1.618) whereas only two vertical proportions in Group II were close to it. Transverse facial proportions in both groups deviated more from divine proportion (1.618) and were closer to silver proportion (1.414). Conclusions: Most of the facial proportions of attractive females in the North-Indian population were close to the divine proportion. Thus, facial divine proportion could be an important factor in the perception of facial attractiveness of North-Indian attractive females.

Photographical evaluation of smile esthetics after extraction orthodontic treatment

Aims: To evaluate and compare the smile esthetics in orthodontically treated subjects and subjects with an esthetically pleasing smile. Materials and Methods: Frontal smiling photographs of 80 subjects in the age group of 18-25 years (mean age of 21.97 years) were taken and divided into Group I (having an esthetically pleasing profile and normal occlusion) and Group II (orthodontically treated). Each Group had 40 subjects, who were further divided into male and female subgroups. Eight transverse and three vertical linear measurements were taken on the frontal photographs and eight ratios were derived. Esthetic scores and other variables were also obtained. The data so obtained were subjected to statistical analysis. Results: All seven ratios did not show any statistically significant differences in both the groups except for ratio 5 (<0.05) in Group IIb. No statistically significant differences were found in the variables of the upper lip curvature, visible marginal gingiva or visible mandibular teeth, except in the visible maxillary first molar (<0.05) for males. The esthetic score showed statistically higher values for males (<0.05) and females (<0.001) in Group I. Lay persons rated significantly higher mean values for esthetic scores in Group Ia (<0.05), Group Ib (<0.001), and Group IIb (<0.01). There were no significant correlations found between the esthetic scores and the seven ratios for both the groups. Conclusion: (1) Females had a more interpremolar/smile width ratio. (2) A greater positive upper lip curvature was found in Group I males and females and was rated higher for esthetic score. (3) The visible maxillary first molar was more in Group II males and females and rated lower for esthetic score. (4) Esthetic scores rated by lay persons were higher for all the subjects.

Comparison of Transverse Dimension in Various Malocclusion Groups: A Posteroanterior Cephalometric Study

Objective: The aim of present study was to evaluate and compare the transverse dimensions in normal occlusion and various malocclusion groups. Materials and methods: This study was conducted on 90 posteroanterior cephalograms of North Indians subjects having age ranged between 18 to 28 years with a mean age of 20.2 years. The subjects were divided into three groups, Group I (Control group), Group II (Class II division 1 malocclusion), Group III (Class III malocclusion). Total 17 cephalometric parameters were used in this study in which 11 were transverse and four were vertical linear measurements, other two were difference between maxillary and mandibular width, and ratio of maxillary to mandibular width. Results: Maxillary width were found to be significantly lower in Groups II and III malocclusion (p < 0.001) than the control group. While mandibular width were found decreased significantly in Group II malocclusion and increased significantly in Group III malocclusion (p < 0.05). Conclusion: Maxillary arches were observed transversely shorter in both Class II division 1 malocclusion and Class III malocclusion in both skeletal as well as dentoalveolar width. Maxilla was found narrower 3.5 mm in Angle’s Class II division 1 malocclusion and 4.00 mm in Angle’s Class III malocclusion as comparison to normal occlusion. Finding of this study also suggest that in malocclusion only jaw bones are affected and other facial bone remains unaffected.