Three dimensional technique of imaging in orthodontics: A review

The process of deploying the two dimensional data in to the three dimensional format is three dimensional imaging. Now a days three dimensional imaging is developing as an emerging factor in the field of dentistry. Three dimensional imaging is useful in the field of orthodontics, to view the anatomy along with the morphology of the bone for desired tooth movement, it is useful in the field of prosthodontics to check or verify the bone morphology, exact height and width of the bone for the process placing implant, three dimensional imaging is quite useful in the field of endodontics along with oral surgery to view the anatomy of the root curvature, to confirm the presence of accessory canals to confirm the bony architectural defect in oral surgical procedures. So in present days three dimensional imaging plays an important role in diagnosis as well as treatment planning in the field of dentistry.

The assesment of pattern of maxillary canine impaction in the Ardabil city

Background & Objective: Impacted teeth are one of the most common reasons for visit- ing dentists and maxillofacial surgeons. During clinical and radiographic examinations and evalu- ations, the dentist sometimes realizes that the patient’s problem is due to the impaction of one or more teeth. Therefore, it is necessary for every dentist to make the necessary and correct decision for the treatment of such teeth. One of the best ways to diagnose impacted teeth is first of all the absence of that tooth in the desired location and clinical evaluation of the patient and secondly to check the radiographic view of the desired area. Impacted teeth can be the source of many prob- lems for various reasons, so in most cases, their extraction is recommended. Knowing how to place the impacted tooth and determining its type and other characteristics of the impaction can help the dentist in choosing the appropriate treatment-surgical method and also prevent complications during surgery. Proper and timely diagnosis of impaction as well as determining its position (buc- cal-palatal-intermediate) in the jawbone can reduce damage to adjacent structures and also affect the treatment plan. Because accurate detection of impacted tooth positions is possible with radiog- raphy, the most accurate radiograph to examine the impacted tooth is cbct images. Therefore, due to possible occlusion injuries and the effect of occlusion pattern on the treatment of these teeth, it is important to study the types of impaction patterns. Therefore, this study was presented with the aim of investigating the impaction pattern of maxillary canine teeth in Ardabil with cbct archive. Materials and Methods: In this descriptive cross-sectional study, CBCT images of 239 patients who met the inclusion criteria were evaluated. Due to the lack of statistics, due to the lack of statistics of maxillary impacted canine teeth in Ardabil, the counting method was used for sampling and stereotypes were identified as maxillary impacted canine teeth as the sample size. The obtained data were analyzed in SPSS24 software. Results: Among the impacted canine teeth studied, 63.2% had palatal, 17.5% buccal and 19.3% had intermediate pattern. Also, 11.2% had damage to adjacent structures and 88.8% had no damage to adjacent structures. Among the types of damage to adjacent structures, 46.9% caused root re- sorption of the first premolars, 34.5% caused root canal resorption, and 18.6% had other damage to adjacent structures. Of these, 50.4% had root curvature and 49.6% had no root curvature, of which 12.1% had severe curvature, 38.7% had mild curvature and 49.2% had severe curvature. Also, the average angle of the incised canine to the lateral incisor was 41.7%. 9% of impacted canine teeth had a root resorption of lateral incisors and 9% did not have a root resorption of lateral incisors. Conclusion: Dentists should treat cases such as maxillary latent canine such as: Examine the occlusion pattern, angle to adjacent teeth, damage to adjacent structures, curvature of the incised canine root, and root resorption of adjacent teeth.

Root morphology of maxillary and mandibular third molars - A potential cause for trans alveolar extractions

Maxillary and mandibular third molars with dilacerated root forms and curvature play a significant role in the treatment planning regarding whether the tooth can be extracted normally or go for trans alveolar extraction. The aim of this study is to assess the association of root curvature and trans alveolar extraction of upper and lower third molars. Preoperative assessment reduces the surgical difficulty and is fundamental for treatment planning and extraction of impacted third molars. We reviewed the case records of the patients who underwent trans alveolar extraction and analysed the data of 94 patients from June 2019 to March 2020 and was tabulated in excel. The data analysis was done in SPSS by IBM, and output was generated as bar charts. In this study, we observed that out of the total 94 trans alveolar extraction performed, 50% of the incidence was below 45 years out of which dilacerated roots were present in 28.7% cases. Results were tabulated and represented as bar charts.so within the limitations of the study we observed that root morphology did not have a significant role in deciding about the treatment whether the teeth will go for open or transalveolar extraction.

MIZ1 regulates ECA1 to generate a slow, long-distance phloem-transmitted Ca2+ signal essential for root water tracking in Arabidopsis

Ever since Darwin postulated that the tip of the root is sensitive to moisture differences and that it “transmits an influence to the upper adjoining part, which bends towards the source of moisture” [Darwin C, Darwin F (1880) The Power of Movement in Plants, pp 572–574], the signal underlying this tropic response has remained elusive. Using the FRET-based Cameleon Ca2+ sensor in planta, we show that a water potential gradient applied across the root tip generates a slow, long-distance asymmetric cytosolic Ca2+ signal in the phloem, which peaks at the elongation zone, where it is dispersed laterally and asymmetrically to peripheral cells, where cell elongation occurs. In addition, the MIZ1 protein, whose biochemical function is unknown but is required for root curvature toward water, is indispensable for generating the slow, long-distance Ca2+ signal. Furthermore, biochemical and genetic manipulations that elevate cytosolic Ca2+ levels, including mutants of the endoplasmic reticulum (ER) Ca2+-ATPase isoform ECA1, enhance root curvature toward water. Finally, coimmunoprecipitation of plant proteins and functional complementation assays in yeast cells revealed that MIZ1 directly binds to ECA1 and inhibits its activity. We suggest that the inhibition of ECA1 by MIZ1 changes the balance between cytosolic Ca2+ influx and efflux and generates the cytosolic Ca2+ signal required for water tracking.

Comparative Evaluation of Taper Preparation Variability of Three Different Niti Files- An In Vitro CBCT Study

The ultimate goal of an endodontic treatment is to achieve the fluid tight seal particularly at the apex as well as in coronal aspect of the root canal system. This is mainly influenced by the cleaning and shaping of root canal system and it has been recognized as an important phase of endodontic therapy. Cleaning and shaping as well as obturation are best accomplished when the file taper claimed by the manufacturer is accurate and the taper of the canal following instrumentation corresponds to the taper of the file. Despite the most advanced technology in manufacturing of dental instruments, variations in endodontic file tapers still exist. Therefore the purpose of this study is to compare the taper variation in root canal preparations among the three different NiTi files using CBCT. Methods: 24 upper 1st molar tooth with mesiobuccal root curvature 15-30 degree were selected and divided into three groups. Mesiobuccal roots (MB1) of three groups were prepared by three different NiTi file system respectively up to size25 taper.06 and CBCT were done separately for each group. The diameter was measured at 1, 3, and orifice in mm and canal taper preparation was calculated using CBCT. Result: Of the 3 file systems, fell within the ±.05 taper variability. All preparations demonstrated variability when compared to the nominal taper .06. Conclusion: Taper preparations of the investigated size 25 taper .06 were favorable but different from the nominal taper.

CT evaluation of apical canal transportation associated with stainless steel hand files, oscillatory technique and ProTaper rotary system

This study used computed tomography (CT) to compare apical canal transportation in mesiobuccal canals of maxillary molars prepared with different techniques. Sixty teeth were assigned to 3 groups (n=20), according to the technique used for root canal instrumentation: hand instrumentation with K-Flexofiles, K-Flexofiles activated by an oscillatory system and ProTaper NiTi rotary system. Pre and post-instrumentation CT images were obtained 3 mm short of the apical foramen and were superimposed to compare canal transportation. Data were analyzed statistically by ANOVA and Tukey's test using the SPSS software (α=0.05). In the buccal direction, the manual technique produced significantly less canal transportation than the oscillatory technique (p<0.05) and both were similar to the rotary technique (p>0.05). In the distal and distopalatal directions, the oscillatory technique produced more canal transportation (p<0.05). In the mesiopalatal direction, the oscillatory technique produced more canal transportation than the manual technique (p<0.05), and both were similar to the rotary technique (p>0.05). In conclusion, all techniques produced canal transportation, and the oscillatory technique produced the greatest removal of root dentin toward the innerside of the root curvature.

Influence of apical enlargement in cleaning and extrusion in canals with mild and moderate curvatures

Optical microscopy and morphometric analysis were used in this study to evaluate, in vitro, the cleaning of the apical region in root canals with mild or moderate curvatures subjected to biomechanical preparation with a rotary system, as well as to assess the amount of extruded material to the periapical area. Lateral incisors (n = 32), 16 with curvature angles smaller or equal to 10º (GI) and 16 between 11º and 25º angles (GII) were submitted to Hero 642 rotary instrumentation with different surgical diameters: (A) 30.02 and (B) 45.02. Irrigation was performed at each change of instrument with 5 mL of ultrapure Milli-Q water and the extruded material through the apical foramen was collected. Root cross-sections were subjected to histological analysis by optical microscopy (×40) and the images were evaluated morphometrically using the Image Tool software. Quantification of the extruded material was performed by weighing after liquid evaporation. ANOVA showed no statistically significant differences (p>0.05) among the groups with respect to the procedures used to clean the apical region. Considering the amount of extruded material, the Tukey's HSD showed that canals with mild curvature prepared with the 45.02 surgical diameter showed significantly higher values (p<0.05) that those of the other groups, which were similar between themselves (p>0.05). In conclusion, the effect of cleaning the apical region did not differ in the groups, considering root curvature and the surgical diameter of instruments used for apical preparation. The amount of extruded material was greater in canals with mild curvature that were prepared with the 45.02 surgical instrument diameter.

Method for determination of root curvature radius using cone-beam computed tomography images

This article describes and discusses a method to determine root curvature radius by using cone-beam computed tomography (CBCT). The severity of root canal curvature is essential to select instrument and instrumentation technique. The diagnosis and planning of root canal treatment have traditionally been made based on periapical radiography. However, the higher accuracy of CBCT images to identify anatomic and pathologic alterations compared to panoramic and periapical radiographs has been shown to reduce the incidence of false-negative results. In high-resolution images, the measurement of root curvature radius can be obtained by circumcenter. Based on 3 mathematical points determined with the working tools of Planimp® software, it is possible to calculate root curvature radius in both apical and coronal directions. The CBCT-aided method for determination of root curvature radius presented in this article is easy to perform, reproducible and allows a more reliable and predictable endodontic planning, which reflects directly on a more efficacious preparation of curved root canals.