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Abstract Background The impaction of mandibular lateral incisors presents significant aesthetic and functional challenges in orthodontics, including Bolton ratio discrepancies and anterior occlusal anomalies. The increasing preference for nonextraction treatment further complicates space management within the dental arch. However, the advent of digital-assisted orthodontic technologies, particularly advanced digital simulations, has revolutionized the precision and effectiveness of diagnosis and treatment planning. These technologies enable clinicians to strategically leverage natural jaw development and create the necessary space for the alignment of impacted teeth without resorting to extraction. Case presentation This case report details the treatment of a 12-year-old male with an impacted mandibular lateral incisor, which resulted in both aesthetic concerns and functional impairments, alongside Class II malocclusion. By employing a digital-assisted diagnostic approach, including comprehensive digital simulations, we meticulously evaluated the feasibility of a nonextraction treatment plan. The strategy centred on harnessing the patient’s mandibular growth potential to expand the available space naturally. The treatment involved surgical exposure of the impacted tooth, followed by precise orthodontic traction guided by continuous digital monitoring. The integration of digital tools throughout the treatment process was crucial in achieving successful eruption and alignment of the impacted tooth, thus restoring optimal aesthetics and function without the need for extraction. Conclusion This case highlights the transformative impact of digital-assisted technologies in the management of complex orthodontic cases, such as impacted mandibular lateral incisors. The successful integration of these advanced tools with a nonextraction treatment approach underscores their potential to significantly enhance clinical outcomes. Digital technologies not only improve the accuracy and effectiveness of treatment but also facilitate a multidisciplinary approach that elevates the standard of patient care in addressing complex orthodontic challenges.

Background: The impaction of mandibular lateral incisors presents significant aesthetic and functional challenges in orthodontics, including Bolton ratio discrepancies and anterior occlusal anomalies. The increasing preference for nonextraction treatment further complicates space management within the dental arch. However, the advent of digital-assisted orthodontic technologies, particularly advanced digital simulations, has revolutionized the precision and effectiveness of diagnosis and treatment planning. These technologies enable clinicians to strategically leverage natural jaw development and create the necessary space for the alignment of impacted teeth without resorting to extraction. Case presentation: This case report details the treatment of a 12-year-old male with an impacted mandibular lateral incisor, which resulted in both aesthetic concerns and functional impairments, alongside Class II malocclusion. By employing a digital-assisted diagnostic approach, including comprehensive digital simulations, we meticulously evaluated the feasibility of a nonextraction treatment plan. The strategy centred on harnessing the patient's mandibular growth potential to expand the available space naturally. The treatment involved surgical exposure of the impacted tooth, followed by precise orthodontic traction guided by continuous digital monitoring. The integration of digital tools throughout the treatment process was crucial in achieving successful eruption and alignment of the impacted tooth, thus restoring optimal aesthetics and function without the need for extraction. Conclusion: This case highlights the transformative impact of digital-assisted technologies in the management of complex orthodontic cases, such as impacted mandibular lateral incisors. The successful integration of these advanced tools with a nonextraction treatment approach underscores their potential to significantly enhance clinical outcomes. Digital technologies not only improve the accuracy and effectiveness of treatment but also facilitate a multidisciplinary approach that elevates the standard of patient care in addressing complex orthodontic challenges. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate and compare the efficacy of 2% lidocaine containing adrenaline with and without hyaluronidase in inferior alveolar nerve blocks for patients requiring bilateral mandibular extractions. Patients and Methods: This was the split‐mouth study conducted on 26 patients requiring bilateral mandibular teeth extraction. All the patients were assigned randomly to one of the two groups: (i) 2% lignocaine HCl + 1:2,00,000 adrenaline + hyaluronidase (75 IU) solution will be administered on one side which is the experimental side and (ii) 2% lignocaine HCl + 1:2,00,000 adrenaline solution on the other side is control side. In the first session, the patients randomly received the inferior alveolar nerve block with or without hyaluronidase in one side of the oral cavity. One week later, the same patient received the other technique which was not received in the first session. We also evaluated the onset, duration and need of any supplementary anaesthesia in both the groups. Results: Comparison of VAS score in the control group (2.73 ± 0.724) and experimental group (3 ± 0.693) showed statistically insignificant results (p = 0.177). Whereas the onset of local anaesthesia showed a statistically significant difference between the two groups (p < 0.001) mean of control group (2.73 ± 0.47) and experimental group (1.15 ± 0.23). Comparison of duration of anaesthesia showed a statistically significant difference (p < 0.001) with the mean duration of the experimental group being higher (106 ± 7.94) than the control group (86.27 ± 3.90). Comparison for the need for supplementary anaesthesia showed no statistically significant difference between the two groups. Conclusion: We conclude that if hyaluronidase is used, better blocks with smaller volumes are produced. LAs with hyaluronidase have been shown to improve the quality and effectiveness of anaesthetic blocks and shorten the time it takes for anaesthesia to begin, accelerate the onset of akinesia and lessen the need for additional anaesthesia. It also increases the duration of anaesthesia. [ABSTRACT FROM AUTHOR]

Abstract Background To investigate the anatomic features of three-rooted deciduous mandibular second molars (DMSMs) in Chinese children by using cone-beam computed tomography (CBCT). Methods A total of 247 CBCT scans of Chinese children were selected and retrospectively analyzed. The occurrence, gender and side predilection of three-rooted DMSMs were examined. The pattern of concurrence of bilateral three-rooted DMSMs, and concurrence of three-rooted DMSM and three-rooted permanent mandibular first molar (PMFM) was analyzed by the concurrence rate and Spearman’s rank correlation test. The geometric parameters of the disto-buccal (DB) and disto-lingual (DL) roots, including the vertical root length, level and angle of distal root furcation, angle of root curvature (by Schneider technique) and the spreading angle, were measured and compared to the three-rooted PMFMs (n = 42) from 100 randomly selected adult subjects. Results The occurrence of three-rooted DMSMs was 24.0% (54/225) calculated by individual, and 18.6% (88/472) by tooth. A significant right-side predilection was detected (23.0% vs 14.2%, p 0.05). The bilateral concurrence rate was 49.0%, and Spearman’s correlation test indicated a significant relationship between the antimetric teeth (rho = 0.609, p

Background: To investigate the anatomic features of three-rooted deciduous mandibular second molars (DMSMs) in Chinese children by using cone-beam computed tomography (CBCT). Methods: A total of 247 CBCT scans of Chinese children were selected and retrospectively analyzed. The occurrence, gender and side predilection of three-rooted DMSMs were examined. The pattern of concurrence of bilateral three-rooted DMSMs, and concurrence of three-rooted DMSM and three-rooted permanent mandibular first molar (PMFM) was analyzed by the concurrence rate and Spearman's rank correlation test. The geometric parameters of the disto-buccal (DB) and disto-lingual (DL) roots, including the vertical root length, level and angle of distal root furcation, angle of root curvature (by Schneider technique) and the spreading angle, were measured and compared to the three-rooted PMFMs (n = 42) from 100 randomly selected adult subjects. Results: The occurrence of three-rooted DMSMs was 24.0% (54/225) calculated by individual, and 18.6% (88/472) by tooth. A significant right-side predilection was detected (23.0% vs 14.2%, p < 0.05), while gender predilection was not detected (p > 0.05). The bilateral concurrence rate was 49.0%, and Spearman's correlation test indicated a significant relationship between the antimetric teeth (rho = 0.609, p < 0.01); whereas a weak but significant co-relationship was detected between the three-rooted DMSM and three-rooted PMFM (right side: concurrence rate = 31.6%, rho = 0.325, p < 0.01; left side: concurrence rate = 23.0%, rho = 0.260, p < 0.01). The length of DL roots in the DMSMs was 7.4 ± 1.5 mm, and the curvature angle was 16.4 ± 11.3 degrees, which was significantly (both p < 0.01) lower than that of the three-rooted PMFMs (root length = 11.0 ± 1.3 mm; degrees of curvature = 34.2 ± 16.1 degrees), whereas the spreading angle of the DL root in DMSMs (34.6 ± 8.4 degrees) was significantly (p < 0.01) greater than in the PMFMs (26.8 ± 6.5 degrees). Conclusions: Three-rooted DMSMs have a high occurrence rate in the Chinese children with a right-side predilection, and they have a weak but statistically significant correlation with three-rooted PMFMs. The DL roots of DMSMs are shorter, less curved, and spreading more widely as compared with those in the three-rooted PMFMs. [ABSTRACT FROM AUTHOR]

Introduction: The aim of this study is to investigate canal configurations and root curvatures of maxillary and mandibular premolar teeth in a Moroccan subpopulation using cone-beam computed tomography (CBCT) images. Materials and Methods: The root curvature and canal configuration of 919 CBCT images of maxillary (358) and mandibular (561) premolar teeth were investigated using “Planmeca viewer” software. Data were analyzed using descriptive statistics. Results: About 46.8% of the maxillary first premolars with two roots had Type I canal configuration of each roots and 27.5% of single-rooted ones presented Type VII. The two-rooted maxillary second premolars showed Type I (39.35%) canal configuration. As for the single-rooted premolars, 32.8% showed Type III canal configuration. The distobuccal curvature was the most frequent for the single-rooted teeth (30.4%) as well as for the palatal (32.4%) root of the two-rooted ones. More than 70% of each root, had Type I of the two rooted mandibular first premolars while 41.8% of the single-rooted premolars had Type V. Type I canal configuration was the most revealed in single-rooted mandibular second premolars with a percentage of 60.6%. Few teeth with two and three roots were seen. The distolingual curvature showed the highest incidence among single-rooted premolars (37.8%) as well as the buccal roots of the two-rooted ones (51.8%). Conclusion: The Moroccan subpopulation's premolars showed a high prevalence of Vertucci's canal configuration Type I with distobuccal curvature for maxillary teeth and distolingual for mandibular teeth.

Introduction: The aim of this study was to compare digital and conventional radiography in determining the working length of dilacerated canals.Methods: Thirty nine human extracted single-rooted teeth with root curvature more than 35 degrees were included in this study. After access preparation, a file was inserted into the canal and advanced until the file tip was visualized at the foramen. With measurement of the file length using a millimeter ruler, true canal length was determined for each canal. Then, teeth were mounted in acrylic blocks and canal length was estimated by using on-screen digital radiography with both 3- and 6-clicks measurement and from conventional radiography by conforming a preserved file on the image of the root canal.Results: There were no significant differences in measurement accuracy between the true canal length and conventional radiographic length, but there were significant difference between both digital radiographic techniques with true canal length. There was no significant correlation between root curvature and canal length estimation error of studied methods.Conclusion: In dilacerated canals, the accuracy of determination of working length by using conventional radiography is higher than digital radiography

Introduction The aim of this study was to determine the morphologic characteristics of mandibular first molars having 2 canals in distal roots. Interorifice distance, buccal bone thickness, and root curvature were evaluated using cone-beam computed tomography images in a Korean population. Methods In total, 1958 mandibular first molars were evaluated in axial, coronal, sagittal, and paraxial planes. Distal roots having 2 canals were classified according to their root and canal shapes (2 roots, 2 canals [2R2C]; 1 root, 2 canals with 2 apical foramina [1R2C(2-2)]; and 1 root, 2 canals with 1 apical foramen [1R2C(2-1)]). The distances between orifices and the distance from the apex to the buccal bone plate were measured for each root canal shape (2R2C, 1R2C[2-2], and 1R2C[2-1]). The curvature of distolingual (DL) roots was classified according to severity using 3-dimensional reconstructed images, and the direction of curvature was determined. The relationships of these characteristics to sex and side were evaluated. Results The prevalences of 2R2C, 1R2C(2-2), and 1R2C(2-1) were 25.89%, 10.32%, and 14.15%, respectively. The distances between distobuccal (DB) and DL orifices were 3.77 ± 0.74 mm for 2R2C, 3.02 ± 0.65 mm for 1R2C(2-2), and 2.44 ± 0.64 mm for 1R2C(2-1). The distances from the buccal plate to the DB canal were 3.84 ± 1.35 mm for 2R2C, 5.33 ± 1.41 mm for 1R2C(2-2), and 5.96 ± 1.63 mm for 1R2C(2-1). The distance from the buccal plate to the DL canal was 9.85 ± 1.46 mm for 2R2C, and 8.28 ± 1.50 mm for 1R2C(2-2). All distances differed significantly according to root canal configurations, and all were greater in men than women ( P < .05), except for the DB-DL orifice distance in 1R2C(2-2) and the DB to buccal cortical plate distance in all root configurations ( P > .05). No significant difference between the left and right sides was found ( P > .05). The prevalence of most severely curved DL roots (type III) was 62.92%, and the direction was commonly toward the buccal side (69.03%). Conclusions The prevalence of mandibular first molars having 2 canals in distal roots was more than 50% in a Korean population. Interorifice distances between DB and DL canals and distances from the apex to the buccal cortical plate differed according to root and canal numbers and shapes. [ABSTRACT FROM AUTHOR]

Introduction: Complete knowledge of root canal curvature is a critical factor in successful dental treatment .The aim of this study was to investigate the direction, radius and degree of curvature of maxillary anterior teeth and the relation between radius and degree of curvature in Babol city. Methods &materials: This study was performed on 242 anterior teeth radiographs were taken by periapical parallel technique and processed by automatic processing. The degree of canal curvature was measured only at mesiodistal direction with Schneider method and classified according to Seidberg method .Statistical analysis was performed by Kruskal Wallis. Results: Out of 242 examined teeth, 153(%62) had curvature that %35.3of them had mesially curve and %64.7 had distally curve. The degree of canal curvature was observed as following: %39.3 with small curvature, %44.6 with intermediate and %16.1 with sever curvature. Also the degree of curvature of central teeth was: 7.2°±9.03°, lateral: 12°±11°and canine: 15°±12°.There was significant correlation between type of tooth and degree of curvature (p=0.000). But there wasn't significant correlation between type of tooth and radius curvature. (p=o.365). Conclusion: In present study, %62 of maxillary anterior teeth had curve and the most degree of curvature was related to the canines. Also it was seen inverted correlation between radius and degree of root curvature but it was insignificant.

Introduction: The aim of this study was to compare digital and conventional radiography in determining the working length of dilacerated canals. Methods: Thirty nine human extracted single-rooted teeth with root curvature more than 35 degrees were included in this study. After access preparation, a file was inserted into the canal and advanced until the file tip was visualized at the foramen. With measurement of the file length using a millimeter ruler, true canal length was determined for each canal. Then, teeth were mounted in acrylic blocks and canal length was estimated by using on-screen digital radiography with both 3- and 6-clicks measurement and from conventional radiography by conforming a preserved file on the image of the root canal. Results: There were no significant differences in measurement accuracy between the true canal length and conventional radiographic length, but there were significant difference between both digital radiographic techniques with true canal length. There was no significant correlation between root curvature and canal length estimation error of studied methods. Conclusion: In dilacerated canals, the accuracy of determination of working length by using conventional radiography is higher than digital radiography. [ABSTRACT FROM AUTHOR]

A series of studies claimed that deep root development of plant established in karst regions was facilitated by fractured bedrock beneath the shallow soils; however, bedrock is not a uniform medium for root proliferation. We hypothesized plant species that survived in different karst habitats had some other rooting characteristics rather than deep penetration. To test the hypothesis, coarse root systems of two widely distributed woody species (one tree and one shrub) growing in three typical rocky karst habitats (shallow soil, loose rocky soil and exposed rock) were excavated in karst region of southwest China. Root systems were investigated based on four parameters: maximum rooting depth, maximum radial extent, root tapering pattern and root curvature. In all the three habitats, maximum rooting depths were no deeper than 120 and 40 cm for the tree and shrub species, respectively. Maximum radial extents were extremely large compared with maximum rooting depth, indicating that rooting characteristics were dominated by horizontal extension rather than deep penetration. Roots of both species growing in shallow soil habitat tapered gradually and curved slightly, which was consistent with the specific characteristics of this habitat. On the contrary, roots of the tree species growing in the other two habitats tapered rapidly but curved slightly, while roots of the shrub species tapered gradually but curved strongly. It was speculated that limited depths and rapid tapering rates of the tree roots were likely compensated by their utmost radial extensions, while the shrub species might benefit from its root curvature as the associated root tropisms may increase the ability of root to encounter more water and contribute to potentially high resource absorption efficiency. Our results highlight the importance of taking shallow-rooted species into account in understanding the distribution of natural plant communities and predicting future vegetation dynamics in karst regions. [ABSTRACT FROM AUTHOR]

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Primary roots of Zea mays cv. Ageotropic are nonresponsive to gravity and elongate approximately 0.80 mm h-1. Applying mucilage-like material (K-Y Jelly) to the terminal 1.5cm of these roots induces graviresponsiveness and slow elongation 28% (i.e. from 0.80 to 0.58mm h-1). Applying mucilage-like material to one side of the terminal 1.5cm of the root induces curvature toward the mucilage, irrespective of the root's orientation to gravity. Applying a 2-mm-wide band of mucilage-like material to a root's circumference 8 to 10mm behind the root cap neither induces gravicurvature nor affects elongation significantly. Similarly, applying mucilage-like material to only the root cap does not significantly affect elongation or graviresponsiveness. Gravicurvature of mutant roots occurs only when mucilage-like material is applied to the root/root-cap junction. Reversing the caps of wild-type and mutant roots produces gravitropic responses characteristic of the root cap rather than the host root. These results are consistent with the suggestion that gravitropic effectors are growth inhibitors that move apoplastically through mucilage between the root cap and root. [ABSTRACT FROM AUTHOR]

The mutant TC 7 of Arabidopsis thaliana (L.) Heynh. has been reported to be starch-free and still exhibit root gravitropism (T. Caspar and B. G. Pickard 1989, Planta 177, 185-197). This is not consistent with the hypothesis that plastid starch has a statolith function in gravity perception. In the present study, initial light microscopy using the same mutant showed apparently starch-free statocytes. However, ultrastructural examination detected residues of amyloplast starch grains in addition to the starch-depleted amyloplasts. Applying a point-counting morphometric method, the starch grains in the individual amyloplasts in the mutant were generally found to occupy more than 20% and in a few cases up to 60% of the amyloplast area. In the wild type (WT) the starch occupied on average 98 % of the amyloplast area and appeared as densely packed grains. The amyloplasts occupied 13.9% of the area of the statocyte in the mutant and 23.3% of the statocyte area in the WT. Sedimentation of starch-depleted amyloplasts in the mutant was not detected after 40 min of inversion while in the WT the amyloplasts sedimented at a speed of 6 μm · h. The gravitropic reactivity and the curvature pattern were also examined in the WT and the mutant. The time-courses of root curvature in the WT and the mutant showed that when cultivated under standard conditions for 60 h in darkness, the curvatures were 83° and 44°, respectively, after 25 h of continuous stimulation in the horizontal position. The WT roots curved significantly more rapidly and with a more normal gravitropic pattern than those of the mutant. These results are discussed in relation to the results previously obtained with the mutant and with respect to the starch-statolith hypothesis. [ABSTRACT FROM AUTHOR]

Thermotropism in primary roots of Zea mays L. was studied with respect to gradient strength (°C · cm), temperature of exposure within a gradient, pre-treatment temperature, and gravitropic stimulation. The magnitude of the response decreased with gradient strength. Maximum thermotropism was independent of gradient strength and pre-treatment temperature. The range of temperature for positive and negative thermotropism did not change with pre-treatment temperature. However, the exact range of temperatures for positive and negative thermotropism varied with gradient strengths. In general, temperatures of exposure lower than 25° C resulted in positive tropic responses while temperatures of exposure of 39° C or more resulted in negative tropic responses. Thermotropism was shown to modify and reverse the normal gravitropic curvature of a horizontal root when thermal gradients were applied opposite the 1 · g vector. It is concluded that root thermotropism is a consequence of thermal sensing and that the curvature of the primary root results from the interaction of the thermal and gravitational sensing systems. [ABSTRACT FROM AUTHOR]

Abstract: Introduction: The prevalence of extra distolingual (DL) roots in mandibular first molars in Chinese population is about 20%. The purpose of this study was to evaluate the difference of root length and root curvatures between distobuccal (DB) and DL roots of three-rooted mandibular first molars in a Taiwanese (Chinese) population. Methods: Of the 293 extracted mandibular first molars, DL roots were present in 29 (9.9%) teeth. Excluding teeth with fractured DB or DL roots, 21 mandibular first molars were further investigated. DB and DL root lengths were measured from the lower level of furcation at the distal surface to the root apex. The curvature of the DL root was measured on mesial-distal and buccal-lingual radiographs by Schneider''s technique. Results: The DL roots were significantly (p < 0.001) shorter than the DB roots with an average of 1.48 ± 0.81 mm. Most DL roots had a greater curvature in a buccal-lingual orientation (36.35° ± 9.38°) than a mesial-distal orientation (9.24° ± 6.10°) and 28.57% of the curved DL roots had the curvature at the apical one third (p < 0.001). Conclusion: The results of this study verified the characteristics of shorter root length and severe buccal-lingual inclination of DL roots in three-rooted mandibular first molars. [Copyright &y& Elsevier]

A gravitational stimulus was used to induce the curvature of the main root of Arabidopsis thaliana. The number of secondary roots increased on the convex side and decreased on the concave side of any curved main root axes in comparison with straight roots used as the control. The same phenomenon was observed with the curved main roots of plants grown on a clinostat and of mutant plants exhibiting random root orientation. The data suggest that the pattern of lateral root formation is associated with curvature but is independent of the environmental stimuli used to induce curvature. [ABSTRACT FROM AUTHOR]

Introduction: Complete knowledge of root canal curvature is a critical factor in successful endodontic treatment. The aim of this study was to investigate the direction, radius and degree of curvature of maxillary anterior teeth and the relationship between the radius and degree of curvature in Babol, a northern city of Iran., Materials and Methods: A total of 242 radiographs of maxillary anterior teeth (central, lateral and canine) were taken by periapical parallel technique and processed by automatic processing. The degree of canal curvature was measured only at mesiodistal direction with Schneider method and classified according to Seidberg method. Statistical analysis was performed with Kruskal Wallis and Mann-Whitney U tests., Results: Overall, 153 (62%) teeth had curvatures; 35.3% were mesially inclined and 64.7% were distally inclined. The degree of canal curvature was categorized into small, intermediate, and severe, that is 39.3%, 44.6% and 16.1%, respectively. The mean value of root curvature angle was 7.24°±9.03° in central incisors, 12.08°±11.02° in lateral incisors, and 15.08°±12.02° in canines respectively. There was significant correlation between type of tooth and degree of curvature (P=0.000). Significant correlation was not found between the type of tooth and radius of curvature (P=0.365)., Conclusion: In the present study, 62% of maxillary anterior teeth had some form of curvatures; highest degrees of curvature were attributed to the canine teeth.