Journal of Indian Orthodontic Society

The present study aims at evaluation and comparison of durability and hygiene between 2 different lingual retainer wires bonded between premolar to premolar, that is, maxillary or mandibular arch in the same patient.

Eighty retainer wires were placed in 40 patients. They were assigned to 2 groups and subjected to 2 different types of retainer wires (multistrand round and 8-braid flat).

The mean durability of multistrand round retainer wire (235.7 ± 67.28 days) was more than 8-braid flat retainer wire (153.5 ± 43.85 days) irrespective of arches to which they were bonded, which was statistically significant. Scores for plaque index, calculus index, and gingival index were found more with 8-braid flat retainers and in lower arch than multistrand round retainer and in upper arch but these are statistically not significant.

The mean durability of multistrand round retainer wire was more than 8-braid flat retainer wire. The analysis did not find any statistical significant association for deposition of plaque, calculus, and gingival inflammation between different retainer wires and between arches.

To investigate the dynamic aspect of attractive smile and smile parameters in different growth patterns.

Participants ranging in age from 17 to 25 years were randomly selected and videographic records of smile were obtained. A panel of two orthodontists, two prosthodontists, and two laypersons were involved in the selection of attractive smile. Inter-examiner variability was also assessed. The final sample of 84 participants with attractive smile were grouped into three categories based on clinical FMA into average, horizontal, and vertical growth pattern. Upper lip length = ULL-R, Lower lip length = LLL-R were measured on rest photographs. Upper lip length = ULL-S, Lower lip length = LLL-S, Upper lip thickness = ULT, Lower lip thickness = LLT, Maxillary incisal display = MID, Interlabial gap = ILG, Outer inter commissural width = ICW, Buccal corridor space = BC were measured on smile photographs. Pearson’s Chi-square test was done for the perception of attractiveness of smile. Differences among the three groups was subjected to one-way analysis of variance and Tukey’s post hoc test.

Highly significant correlation was observed among orthodontists, prosthodontists, and laypersons in assessing attractiveness of smile. Vertical parameters such as upper lip length at rest, upper lip length during smile, lower lip length at rest, lower lip length during smile, and lower lip thickness (LLT) were significantly increased in the vertical pattern when compared with the average and horizontal growth pattern, whereas buccal corridor space was the least in horizontal growth pattern.

Growth patterns appear to have an influence on perception of smile esthetics and smile parameters. This suggests that care should be taken while framing treatment goals considering the significant differences among growth patterns. Strong correlation was observed among orthodontists, prosthodontists, and laypersons in assessing attractiveness of smile. ULL-R, ULL-S, LLL-R, LLL-S, and ΔULL show a significantly higher value in vertical growth pattern when compared to average and horizontal growth pattern. The buccal corridor space (BC) among the participants was the least in horizontal growth pattern.

The study was conducted to analyze the stress distribution and displacement due to three different vertical positions of the mini-implant assisted rapid palatal expansion (MARPE) appliance.

A three-dimensional finite element meshed model was created of the maxillofacial complex with the help of cone beam computed tomography (CBCT) digital imaging and communication in medicine (DICOM) data of a patient with transverse maxillary deficiency using materialise interactive medical image control system (MIMICS) software. Three different groups with varying expander heights were used to study the expansion effects on the maxillofacial structures. von Mises stress and displacement at various skeletal and dental points were evaluated using ANSYS software.

In the midpalatal suture, the posterolateral portion of the hard palate and the maxillary and pterygoid bones showed the greatest amount of stress distribution and displacement pattern. Group 1 showed the maximum amount of transverse displacement compared to groups 2 and 3. Sagittally, all the teeth had a forward displacement. Vertically, groups 2 and 3 showed clockwise rotation of the occlusal plane, while all teeth showed downward displacement in group 1.

In conclusion, a V-shaped expansion in the maxilla with a superior and posterior vertex was noted. Group 1, that is, appliance placed in close approximation to the palate, showed greater displacement compared to groups 2 and 3.

Space closure is the most common treatment mechanic used in orthodontics in clinical practice. It can be done with friction and frictionless mechanics, and nowadays by using mini-implants. These mini-implants provide an absolute source of anchorage to obtain dental and soft tissue changes that are desired, thus helping to improve the patient’s profile.

To evaluate the stress distribution patterns in the tooth, bone, and periodontal ligament in mini-implants placed at different heights and angulations for retraction and intrusion of maxillary incisors using finite element model (FEM).

FEMs of maxillary teeth and periodontal ligament housed in alveolar bone with the first premolars extracted were constructed. These models were further divided into two groups based on the number of implants. In group I, two implants were placed bilaterally between the second premolar and first molar at variable heights (7, 10, and 13 mm) and at different angulations (45° and 60°) to the long axis of the occlusal plane. In group II, along with the two bilateral mini-implants, an additional mid-implant was placed between two central incisors. These models were simulated using ANSYS 19.2 version software.

The maximum distribution of stress (MPa) in hard bone, soft bone, and implant was seen in the FEM 7 model and was 17.65, 0.210, and 61.62 MPa, respectively, during the retraction and intrusion of maxillary anterior teeth. The highest stress distribution (MPa) was seen in the lateral incisor tooth in FEM 7 model (0.748 MPa) and also in the periodontal ligament around the lateral incisor in FEM 7 model (0.684 MPa).

The stress distribution was found to be highest in the lateral incisor tooth, periodontal ligament of the lateral incisor, and hard bone. The stress distribution pattern showed variation with different heights and angulations of the mini-implant. As the angle of insertion of the mini-implant to the long axis of the occlusal plane increases, the stresses generated in the bone decrease.

Mini-screws are valuable devices in orthodontic treatment as they allow effective anchorage. Relocation of a mini-screw may be required due to anatomical limitations.

To compare the morphology and surface characteristics of three brands of mini-screws before and after use and to check their viability for reinsertion.

Mini-screws of three commercially available brands, Group I: Orlus, Ortholution, Korea, Group II: Absoanchor, Dentos, Korea, and Group III: S.K. surgical, India, were evaluated for the sharpness of their threads and active tip, surface roughness, and surface chemical composition using scanning electron microscope (SEM)–energy dispersive spectroscope (EDS) before and after clinical use.

The sharpness of threads did not differ before and after use in any of the groups. The mean tip deformation values in Groups II and III post-insertion were significantly higher than pre-insertion. The SEM images obtained post-insertion revealed loss of gloss and surface finish with a dull appearance in all groups, but most evident in Group I. EDS analysis post-retrieval shows an increase in the amount of carbon and oxygen in Groups II and III.

Mini-screw reuse within the same patient is possible if proper recycling is done, and pilot drilling is done to overcome the decreased cutting ability of the tip due to deformation.

The sella turcica (ST) is an important anatomical landmark occasionally filled with cerebrospinal fluid in a condition known as empty sella disorder (ESS). ESS occurs when the pituitary gland contracts due to issues with the contents inside the ST and has been linked with malocclusion, which remains less explored.

This study intended to investigate morphological and morphometric variations of ST in terms of sex, age, and race as well as document the prevalence of malocclusions in a South African adult sample.

ST scans of 32 patients and 21 dry and cadaveric skulls were investigated. Volume was measured using plasticine, and other parameters were measured using a sliding vernier caliper and 3D slicer software.

The width is the only linear parameter that showed significant (p < .05) variations against sex. The mean length, width, AP diameter, and volume variation between groups ages 31-50 and 51-70 were 0.54 mm, 3.60 mm, 1.48 mm, and 39.47 mm. The length of ST in Black people varied from that of White people by 1.58 mm. The width of ST in Black people was 10.90 ± 2.68 mm, and in White people, it was 12.99 ± 2.41 mm, which was statistically significant (p < .05). Class I malocclusion was the most common type in this study, and bridging of the ST was common in class II.

This study revealed that the ST varies among different ethnic groups. Also, the width of the ST can be used to identify sex, but the size of the ST at various ages cannot be used to gauge an individual’s growth because there were no significant differences.

The purpose of this research was to compare the adhesive residual score/adhesive remnant index (ARI) and shear bond endurance between the two orthodontic bonding systems for zirconia surface bonding: Self-etch (Scotchbond Universal) and total-etch (Transbond XT).

Color-coded acrylic blocks embedded with zirconia slabs were prepared, and the orthodontic brackets (ceramic) were bonded using either the total-etch or self-etch system. Group 1, represented by pink-colored blocks (N = 12), accommodated 12 zirconia surfaces using the total-etch system, while Group 2, represented purple-colored blocks (N = 12), also housed zirconia surfaces using the self-etch system. The shear bond strength was evaluated using an Instron Universal Testing Machine, and ARI scoring was done upon debonding. The statistical software SPSS was used for the analyses.

The average bonding strength for the Scotchbond Universal etch system was 6.21 ± 0.76 MPa, while for the total-etch system, it was 5.59 ± 1.37 MPa. The ARI scores revealed that 83% of surfaces bonded with the self-etch system had no adhesive residue (ARI score 0), compared to 66% for the total-etch system.

The self-etch bonding agent demonstrated superior bond strength (6.2 MPa) compared to the total-etch system (5.6 MPa). Furthermore, it exhibited better ARI scores, indicating minimal adhesive residue. These findings suggest that the self-etch system is preferable for bonding ceramic brackets to zirconia crowns, offering improved bonding efficacy and ease of clean-up.

The efficiency of tooth movement associated with orthodontic sliding mechanics can be compromised by friction between archwire and tube or bracket slot. Orthodontic brackets and archwires are important constituents of an orthodontic appliance system. Friction is an uncontrolled variable of particular interest when continuous arch techniques are used to align and move teeth by way of sliding a tube or bracket along an arch.

Comparison of frictional resistance between different bracket systems of 3M and MO brands in combination with different wires of 3M, MO, and G&H brands. Evaluation of frictional resistance between two different types of bracket systems and different types of wire combinations.

Two types of bracket systems were used: metal bracket system and ceramic bracket system (3M and MO brands). Four different orthodontic wire alloys were used: stainless steel (SS), TMA, NiTi, and CuNiTi (3M, MO, and G&H brands). A rectangular block made up of self-cure acrylic resin was designed to hold the bracket during the mechanical test. Each bracket base was glued to an acrylic block with cyanoacrylate glue. The wire segment was inserted into the bracket and was ligated passively with SS ligature wire. The bracket–wire combination was submitted to mechanical tests with a universal testing machine. One end of the acrylic block was mounted to the lower grip of the universal testing machine. The free end of the archwire was fixed to the upper grip of the universal testing machine. The friction which was generated between the wire and bracket was measured under dry conditions and at room temperature. The test wire was pulled through the bracket at a speed of 0.5 cm/min. The load cell registered a maximum force level. This data was stored in the computer and was submitted to statistical analysis, and parameter tests were applied.

The highest mean friction resistance of 5.998 N was generated by group B2-E2 (ceramic bracket – MO + TMA archwire – MO). The lowest mean friction resistance of 2.552 N was generated by group A1-C1 (metal bracket – 3M + SS wire – 3M). There was a statistically significant difference between the friction generated by the metal bracket on SS archwire and the ceramic bracket on TMA archwire regardless of 3M or MO brand material (p value < .0001) and metal bracket (p = .0004).

Perceiving a need for orthodontic treatment is a heuristic process usually conditioned by the interplay between motivational factors and influencing factors in a community with orthodontic awareness and a history of already ongoing or completed orthodontic treatments. Using a verbally assigned index to elicit candid responses, the current study aimed at assessing reluctance toward orthodontic treatment in adolescents with clinically ascertained malocclusion in a community with no prior history of orthodontic treatment.

Tribal adolescents from two regions with clinically ascertained malocclusion but no previous access to orthodontic treatment were evaluated for willingness or reluctance to undergo orthodontic treatment using a verbally assigned Simplified Malocclusion Index for Layperson Evaluation (SMILE index).

2,835 tribal adolescents belonging to the tribal regions of Paderu and Parvathipuram in Andhra Pradesh were questioned to analyze factors related to reluctance toward orthodontic treatment in those with malocclusion. Necessary permission and consent were obtained from the institutional ethical clearance committee, tribal authorities, school authorities, and parents or guardians. Clinical screening employing appropriate infection prevention protocol under natural daylight was used to determine the presence of malocclusion. A verbally assigned SMILE index in the vernacular language of the students with malocclusion was used to record candid responses to analyze possible reluctance toward treatment. Specific reasons for reluctance to undergo treatment were documented and tabulated separately. Pearson chi-square statistical analysis of the data was performed to determine if there was any gender bias.

At Paderu, of the 68% of the tribal adolescents presenting with malocclusion, the verbally assigned SMILE index revealed that 84.03% of the adolescents were reluctant. The chi-square statistical analysis of the data indicated a gender bias (X² (1, N = 2,016) = 35.99, p < .0001). At Parvathipuram, of the 93% of the tribal adolescents presenting with malocclusion, the SMILE index assigned revealed that 93.05% of the adolescents were reluctant. The chi-square statistical analysis of the data indicated a gender bias (X² (1, N = 819) = 6.42, p = .11).

The use of the SMILE index allows for a qualitative analysis of reluctance based on the candid subjective inputs from each individual. The study reveals a high degree of orthodontic awareness among the tribal adolescents, and any reluctance toward orthodontic treatment is mainly related to difficulty in access to treatment.