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BACKGROUND: The volumetric relationship between the tongue and the oral cavity is an important factor in tooth alignment and occlusion. The aim of this study was to evaluate the difference in tongue and airway volume in skeletal Class I and Class II malocclusion. MATERIALS AND METHODS: The CBCT data which comprised of 30 skeletal Class I and 30 skeletal Class II was stored in DICOM format. Tongue volume and airway volume was analyzed with the help of 3D dolphin software. Values obtained were subjected to statistical analysis with help of SPSS. RESULTS: Skeletal Class I pattern had more tongue volume with a mean of 45.32 mm3 than skeletal Class II pattern with mean value of 40.27mm3 with P value of

Background. Although there are various intraoral and extraoral appliances for anchorage management in orthodontics, most fail to preserve the anchorage efficiently. Thus, there is a need for an appliance that can preserve anchorage in the sagittal, vertical, and transverse directions with good patience compliance and cost-effectiveness. This study compared the efficacy of butterfly arch and transpalatal arch (TPA) as an anchorage reinforcing unit during orthodontic space closure using a linear finite element model. Methods. A 3D model of the maxilla and associated structures was developed from CT images of an individual’s skull at a slice thickness of 1 mm. The magnitude of movements of anchor teeth in vertical, horizontal, and transverse directions was calculated in first premolar extraction cases during anterior retraction using a linear finite element model analysis and compared in two situations―butterfly arch and TPA attached to maxillary first molar for anchorage. Results. The anterior teeth had similar movements in the case of TPA and butterfly arch. There was more mesial and lingual movement in the first molars with TPA than in the butterfly arch, which had buccal but no mesial movement. The anterior teeth showed extrusion and the second premolars showed intrusion with TPA. Also, the von Mises stress and maximum principal stress were maximum with TPA at the cervical region of anterior and posterior teeth compared to the butterfly arch, where both stresses were uniformly distributed all over the teeth. Conclusion. A butterfly arch with its unique design, configuration, and biomechanical properties can be used as a device that can maintain the posterior anchorage efficiently

Background: Mandibular buccal shelf (MBS) offers good quality and quantity of bone for orthodontic bone screw (OBS) insertion. Despite several reports of treated patients, there are numerous variables in selecting the exact placement site for OBS placement in the MBS. There are also anatomical variations in this area which must be considered. Objectives: This study aims to measure and compare the MBS bone characteristics for OBS placement using cone beam computed tomography (CBCT) between two different facial types. Materials and Methods: Eighty CBCT samples were collected (40 samples of group A horizontal growers and 40 of group B vertical growers). Each CBCT image was reconstructed and oriented with CS 3D CBCT software. The cortical bone thickness, the slope of the MBS, and buccolingual inclination of mandibular second molar were measured and analysed. Result: Cortical bone thickness among horizontal growers was 5.23 ± 0.58 mm and among vertical growers was 4.85 ± 0.37 mm. The slope of MBS among horizontal growers was 60.83 ± 6.15 degrees and among vertical growers was 66.75 ± 6.27 degrees. In both the parameters there was a statistically significant difference between the groups. There was no significant difference between the groups for the buccolingual inclination of 2nd molar. Conclusion: Increased cortical bone thickness and the flatter slope of MBS at the 2nd molar region allows for easier placement of OBS in horizontal growers than in vertical growers.

Introduction: Application of orthodontic forces to a tooth is characterised by extensive macroscopic and microscopic changes during remodelling which occurs in the Periodontal Ligament (PDL), alveolar bone and gingiva. This occurs mainly due to the local stresses and strains subjected on the supporting tissues. As direct measurement of these parameters is almost impossible, Finite Element Method (FEM) is an effective method for calculating stress and strain distribution on the alveolar bone. Aim: To assess the stress and strain distribution in the cortical and cancellous bone around maxillary central incisors during the process of diastema closure with a constant force using FEM. Materials and Methods: A three-dimensional computer model of anterior segment of the maxilla simulated from a CBCT scan was reproduced using MIMICS software and they had varying width of midline diastema of 4 mm, 3 mm and 2 mm. Each tooth was designed with a bracket on the labial surface and a 0.019×0.025 orthodontic stainless steel wire. A 1.5 N of force was applied on the labial surface of the brackets. Stresses and strains around the two central incisors on the alveolar bone were calculated. Results: In the cortical bone, maximum compressive stress (Von-Mises stress) was concentrated at the mesial side and tensile stress (principle stress) on the distal side near the cervical region of the central incisors in all the 3 models. Maximum stress was seen in the 2mm midline diastema model. In the cancellous bone, both these stresses were concentrated along the roots of central incisor cavity more towards the middle of the tooth in all the 3 models. In the longitudinal section, stress and strain was more concentrated at the cervical region gradually decreasing as they reached apex of the tooth in cortical bone and in the cancellous bone maximum stress was observed in the middle third. Conclusion: Stresses in the cortical bone increases when the diastema gap is small while strain in cancellous bone increases when the midline diastema width is large. The stresses in cancellous bone remain constant in all the 3 models. Graphically the strains were more concentrated near cervical region of the teeth in both the cortical and in cancellous bone maximum stress was observed in the middle third.

OBJECTIVE: To determine the prevalence of malocclusion and orthodontic treatment need in a sample of Omani adolescents aged 11–16 years. MATERIALS AND METHODS: The total sample included 854 adolescents with 387 boys and 467 girls between the age of 11 and 16 years with no previous orthodontic treatment history. The study design was cross-sectional. The parameters studied were skeletal relationship, lip competency, teeth impactions, missing teeth, contact point displacement, crowding, spacing, incisors and molars classification, overjet, overbite, crossbite, oral hygiene and caries. The Index of Orthodontic Treatment Need (IOTN) was used to study the need for orthodontic treatment for the total sample. RESULTS: There was a high prevalence of Class I jaw relationship (86.2%). About 81.6% of the sample studied had Class I molar relationship and 73.8% had Class I incisors relationship. About 61.4% of the sample had no contact displacement, while 5.2% had contact displacement >4 mm. Severe crowding in the maxilla was found in 2.3% while spacing was found in 24.2%. Around 11% of the sample studied had Class II div 1 incisors relationship, 13.5% Class III and only 1.8% had Class II div 2 incisors relationship. Only 8.6% of the sample studied had an overjet >6 mm while 16.3% had a deep bite and 0.2% had anterior open bite of >4 mm. Teeth impaction was found in 11.7% while permanent missing teeth was present in 1.8%. The results showed that 13.9% had a very great need for treatment while 43.2% of the sample did not need any treatment. CONCLUSION: Among the Omani adolescents, there was a high prevalence of Class I jaw relations and Class I molar relationship. The prevalence of malocclusion and treatment need in Omanis shows some variation when compared to other ethnicities.

Background and Aims: We aimed to investigate gingival index changes and oxidative stress in orthodontic patients with and without the use of fluoridated agents over a 6-month period., Materials and Methods: Ninety subjects divided into three groups (30 untreated controls, 30 with fixed appliances using nonfluoridated toothpaste, and 30 with fixed appliances using fluoridated toothpastes and mouthwashes ) comprised the sample. The Loe gingival index was used to rank gingival health at four specific time periods in the groups to determine differences (before, at 7 days, 30 days, and 6 months). Gingival crevicular fluid was evaluated for cytokines (interleukin [IL]-1β and tumor necrosis factor [TNF]-α) to determine differences in oxidative status between the groups., Results: Controls showed no changes in gingival index throughout the 6-month observation period. There was a deterioration in gingival health in both the fluoridated and nonfluoridated groups till 6 months. IL-1β levels in the fluoridated group increased from the 7 th day, reached a peak at 30 days, and remained slightly elevated at 6 months. The nonfluoridated group also showed elevated levels at all tested time periods, but levels were lower as compared to fluoridated samples. The differences in IL-1β values between the fluoridated and nonfluoridated treated groups were significant. TNF-α levels in the three groups also showed a similar pattern with elevated levels seen in both the treated groups at the 7 th , 30-day, and 6-month periods. The fluoridated group showed the highest levels at three time periods which was statistically significant., Conclusions: Gingival health of subjects treated with fixed orthodontic appliances deteriorated from appliance placement till a 6-month time period. Cytokines such as IL-1β and TNF-α associated with oxidative stress during orthodontic treatment increased in both the treated groups, with higher levels in fluoridated subjects. Long-term consequences of oxidative stress changes need further investigation., Competing Interests: There are no conflicts of interest., (Copyright: © 2022 Indian Society of Periodontology.)