Molar Rotation Research Articles

Three-dimensional assessment on digital cast of spontaneous upper first molar distorotation after Ni-ti leaf springs expander and rapid maxillary expander: A two-centre randomized controlled trial.

The aim of this randomized controlled trial (RCT) was to evaluate the spontaneous distorotation of upper first permanent molars and the transverse dentoalveolar changes on digital casts in growing patients following maxillary expansion treatment using either the Leaf Expander® or the rapid maxillary expander (RME), both anchored to the deciduous second molar. This study was a two-arm, parallel-assignment, RCT with a dual-centre design conducted at two teaching hospitals in Italy. Inclusion criteria included maxillary transverse deficiency, prepubertal development stage (cervical vertebra maturation stage [CVMS] 1-2) and early mixed dentition with fully erupted upper first permanent molars. Exclusion criteria were systemic diseases or syndromes, CVMS 3-6, agenesis of upper second premolars, unavailability of the second deciduous molar for anchorage and Class III malocclusion. Patients were randomly assigned to the Leaf Expander® or RME group using a computer-generated randomization list created by a central randomization centre. Randomization was conducted immediately before the start of treatment. The intervention involved treatment with either the Leaf Expander® or the RME. Both devices were anchored to the second deciduous molars. Following randomization, patients were further categorized based on the presence of no crossbite, unilateral crossbite or bilateral crossbite. The primary outcome measure was the distorotation of the upper first molar (U6). Secondary outcomes included measurements of interdental linear dimensions, specifically upper inter-canine width (53-63), upper inter-molar width (MV16-MV26) and upper inter-deciduous second molar width (55-65). The examiner analysing the digital casts was blinded to the treatment groups to prevent detection bias and ensure objective assessment. However, due to the nature of the intervention, blinding was not feasible for the patients and clinicians involved in administering the treatment. A total of 150 patients were enrolled and randomly assigned to two groups: 75 to the Leaf Expander® group and 75 to the RME group. Recruitment started in November 2021 and was completed in November 2022. At the time of analysis, the trial was complete with no ongoing follow-ups. ANOVA tests revealed no significant differences between the three subgroups (no-cross, unilateral-cross and bilateral-cross) within both the Leaf Expander® and RME groups at T0. The Leaf Expander® demonstrated significantly greater distorotation in the unilateral crossbite subgroup compared to the RME (p = .014). In terms of total molar distorotation, the Leaf Expander® appliance showed a significantly greater effect (12.66°) compared with conventional RME (7.83°). Linear regression analysis demonstrated a significant correlation between the extent of expansion and the degree of molar rotation. Maxillary expansion resulted in significant spontaneous molar distorotation when the appliance was bonded to the second deciduous molars. The Leaf Expander® exhibited significantly greater molar distorotation compared with conventional RME. The degree of molar distorotation was correlated with the extent of expansion obtained on the second deciduous molar. The trial was registered at ClinicalTrials.gov (ID: NCT05135962).

Clinical efficiency of new generation elastomeric ligatures over conventional: An in-vivo study

Friction being an imperative element in clinical orthodontics affects all stages of treatment and high frictional forces can affect the treatment duration and outcome in a deleterious manner. This study was done to appraise frictional resistance of non-conventional elastomeric modules in comparison with conventional elastomeric modules, during the retraction of teeth. The study sample size includes 30 patients (11 males and 19 females) undergoing orthodontic treatment. They were grouped into 3, namely, Group A- Slide nonconventional elastomeric ligatures Group B- super slick nonconventional elastomeric ligatures, and Group C- the conventional ligature. The study models were obtained to assess canine retraction rate, anchor loss, canine rotation, and molar rotations at different time intervals and subjected to statistical analysis. : The canine retraction rate(maxilla) for Group A, B and C was 1.674+/-0.092, 1.187+/-0.156, and 1.147+/-0.113,(mandible)1.765+0.099, 1.300+0.099 and 1.270+0.111 respectively. Mean anchorage loss(maxilla) group A- 1.054mm, group B- 1.080mm, group C -1.715mm (mandible) 1.024mm, 0.952mm and 1.664mm respectively. Canine rotation(maxilla) of Group A, B and C is 8.550+/-1.506, 5.300+/-1.386, 6.100+/-1.315and(mandible) 8.930/-+1.474, 5.830+/-1.096, 6.880+/-1.813 respectively. Mean molar rotation (maxilla) 2.580+0.735, 2.210+0.549 and 2.210+0.700 (mandible)2.900+0.541, 2.650+0.639 and 2.780+0.604 in group A, B and C respectively. Mean anchor loss was lesser in non-conventional modules, canine retraction rate was higher with Slide ligature, canine rotations were least in superslick more in Slide ligature, and rotation of molar was apparent for all the groups.

Empirical Chiroptical Analyses of Vicinal Bromochloro Natural Products by van't Hoff's Principle of Optical Superposition: Assignment of the C-16 Configurations of Callophycols A and B.

A simple empirical method is described that allows the assignment of absolute configurations of natural products containing chiral vicinal bromochloro (VBC) units, including the bromochloro substituted isoprenyl units present in the structures of antiproliferative halomon (1a) and its halogen-swapped isomer iso-halomon (1b) from the red alga, Portieria hornemannii, and callophycols A (3) and B (4) from Callophycus serratus. The relative configurations of 3 and 4, published in 2007, were incomplete: C-16 was left unassigned. It is now shown that the additivity of molar rotations, [M]D (herein, abbreviated [M])─a consequence of van't Hoff's principle of optical superposition─could be used to deconvolute rotatory contributions, designated as [MX] and [MY] of the two remotely spaced chiral substructures within 3 and 4 using simple arithmetic. Input of proxy values, [M Y1] and [MY2], for the two different VBC units in two equations for [MX] and application of a "conditional test" returns the same value for [MX] only when a proxy with the correct configuration is included. It is revealed that 3 and 4 have opposite configurations at the C-16 stereocenter: 16S and 16R, respectively. Two important implications lie in these findings: 3 and 4 appear to qualify as paired-regioisomers, coupled through a putative dyotropic rearrangement (DR), and the biosyntheses of other Callophycus secondary metabolites, now numbering over 50, are tightly controlled by stereoelectronic considerations including neighboring group interactions of the DR. It now appears, counter to earlier suggestions, that the chirality of Callophycus secondary metabolites, despite their high chemodiversity, are surprisingly highly conserved. Enantiofacial halogenation additions to the C═C double bonds of precursor alkenes appear to direct the formation of the remaining stereocenters at both the halogenated benzoate-decalin core and the distal VBC of 3 and 4. A consistent hypothesis is proposed to account for macrolactonizations in other Callophycus natural products including bromophycolides A and B. The conditional test of molar rotations was applied in a different context to understand the chiroptical properties and trends observed in the highly iodinated meroditerpenes, iodocallophycols A-E, also from Callophycus sp., resulting in the revision of the configuration of callophycol E from (10R,14R) to (10S,14S).

Tip, torque and rotation of maxillary molars during distalization using Invisalign: a CBCT study

BackgroundDesirable molar distalization by bodily movement is challenging and can be difficult to achieve. This study investigated changes in molar angulation (mesiodistal tipping), molar inclination (buccolingual torque) and rotation during distalization using clear aligner therapy (CAT).Materials and methodsThis retrospective study included 38 cone beam computed tomographic images (CBCTs) taken for patients treated with molar distalization using CAT. The study evaluated pre- (T0) and post-treatment (T1) CBCTs of 19 adult patients (36.68 ± 13.50 years) who underwent maxillary molar distalization using Invisalign® aligners (Align Technology, Inc., San José, CA, USA) with a minimum of 2 mm distalization. Changes in maxillary molar tip, torque and rotation were measured for 61 molars (183 roots). Paired t-test was used to evaluate the differences between pre- and post-treatment readings. The level of significance was set at p ≤ 0.05. The reproducibility of measurements was assessed by the intraclass correlation coefficient (ICC).ResultsMolar angulation did not show significant change after distalization (p = 0.158) however, there was significant increase in buccal molar inclination (p = 0.034) and mesiobuccal molar rotation (p < 0.001).ConclusionMolar distalization of 2 mm did not cause significant molar tipping. Maxillary molars showed significant buccal inclination (increased torque) and mesiobuccal rotation after distalization.

Evaluation of Upper 1st Molar Rotation During Maxillary Canine Retraction in 1st Premolar Extraction Cases at 6 Weeks Reactivation Interval: A Clinical Trial

Evaluation of Upper 1st Molar Rotation During Maxillary Canine Retraction in 1st Premolar Extraction Cases at 6 Weeks Reactivation Interval: A Clinical Trial

Evaluation of anchorage loss after en masse retraction in orthodontic patients with maxillary protrusion using friction vs frictionless mechanics: randomized clinical trial.

To evaluate anchorage loss after en masse retraction in bimaxillary dentoalveolar protrusion patients using friction vs frictionless mechanics. Thirty patients with bimaxillary dentoalveolar protrusion needing extraction of upper first premolars and en masse retraction with maximum anchorage were included in this two-arm, parallel, single-center, single-blinded randomized clinical trial with a 1:1 allocation ratio using fully sealed opaque envelopes. Friction group retraction utilized elastomeric power chain between miniscrews and hooks crimped mesial to upper canines on 17 × 25 stainless steel archwire. Frictionless group used customized T-loop springs loading upper first molars indirectly anchored to miniscrews. Activation was every 4 weeks until full retraction. The primary outcome assessed was anchorage loss evaluated at cusp tip and root apex of the first molar. First molar rotation, incisor tip and torque, and root resorption of anterior teeth were evaluated on digital models and cone beam computed tomography taken before and after space closure. Anchorage loss at crown of first molar was significantly more in frictionless group by 2.1 mm (95% CI = -0.4 to 3.5), (P = .014), while there was no significant difference in anchorage loss at root apex between groups. Significant mesial in molar rotation of 6.672° (95% CI = 12.2-21.2), (P = 0.02) was greater in the frictionless group. Both groups showed comparable tip, torque, and root resorption values. No severe harms were reported. There was mild gingival overgrowth and inflammation in the frictionless group due to T-loop irritation. Extra anchorage considerations are needed during en masse retraction when frictionless mechanics is implemented as higher anchorage loss and molar rotation were detected. No difference in tip, torque, and root resorption was observed.

Headgear therapy in children with Class II malocclusion and the role of compliance on treatment outcome: A nine-month randomized controlled trial.

To evaluate three-dimensional movements of maxillary teeth during headgear treatment in Class II growing children, using digital analytical tools, and to determine the effects of compliance on these movements. A 9-month parallel-group randomized controlled trial was carried out on 40 children with Class II malocclusion, aged 8-12 years, half assigned to receive a cervical headgear and half to a no-treatment group, using block randomization. Subjects in the treatment group were instructed to wear the headgear for 12 hours daily and monitored using an electronic module. After 9 months, the following dental outcomes were measured: first maxillary molar distalisation, rotation, tip and torque, arch depth, and interpremolar and intermolar distances. Caregivers and participants were not blinded to group assignments, but those assessing outcomes were. Linear regression models were used to detect differences between groups and correlation coefficients to find correlations between compliance and dental outcomes. All 40 included patients were analysed. A significant difference in molar distalisation was observed between the treatment (1.2 mm) and control groups (-0.2 mm). Arch depth change was also increased to a larger extent in the treatment groups (1.3 mm vs 0.1 mm), as was the interpremolar distance (1.9 mm vs 0.4 mm). In contrast, no significant differences in molar rotation or torque change were observed. With regard to compliance, average compliance was 55%. A significant correlation was found between molar distalisation and compliance in the treatment group. Headgear therapy has significant effects on molar distalisation, arch depth, and arch width. Compliance has a significant positive effect on molar distalisation.

UnBand- Perioprotect palatal connector

The field of orthodontics demands versatility in appliances for faster and efficient treatment process. One such versatile auxiliary used is the Transpalatal arch for anchorage and for active tooth movements such as for correcting molar rotation and up righting, stabilization of posterior transverse dimensions during treatment, and maintenance of leeway spaces during the transition of the dentition.The process of insertion of the Transpalatal arch is cumbersome. To address these limitations, alternative methods for using the Transpalatal arch has been innovated where design experimented does not demand laborious procedures and can be done inhouse and is cost effective.There are three methods custom made Custom made Transpalatal arch is fabricated. Lingual/ Palatal surface of the molar is etched and bonding agent applied and cured. The stub of the TPA is then adapted to the tooth surface and flowable resin is applied and then cured. Preformed mesh is cut and welded onto the lingual sheath thereby converting a weldable lingual sheath into a bondable sheath. Mesh is then adapted onto the prepared tooth surface and then cured with composite. The mesh provides mechanical retention which is helpful for bonding. The custom made Transpalatal arch is now inserted. Vertical and horizontal grooves are made on the posterior side of the lingual sheath using bur. The sheath is then sandblasted to create a rough surface which provides a micromechanical retention area. This sheath is then bonded directly onto the tooth surface and Transpalatal arch inserted. The results suggest that orthodontic appliances without bands are preferable. Bonded TPA’s are less invasive and also requires less chairside time.Bonded TPA’s can overcome these issues and assist both the clinician and the patient in achieving faster orthodontic treatment and reducing discomfort. Therefore, through these innovations, a clinician can judiciously choose based on requirements and employ it effectively in orthodontic treatment.

Total mesialization of the mandibular dentition using amini-implant-supported device : Afinite element analysis.

Total mandibular arch mesialization using mini-implants is challenging due to anatomic limitations. The aim of this study was to introduce amini-implant-supported device for total mesialization of the mandibular dentition and to analyze the biomechanical properties of the device. Finite element models were constructed to explore the effect of friction and force direction on the force transmission efficiency of the device. In addition, the three-dimensional displacement of each tooth was evaluated with two force application points (2 or 8 mm hooks) under three force conditions (symmetric: 150 g of force on both sides, or asymmetric: 100 and 200 g of force on each side). The force transmission efficiency was 66.7% under afriction coefficient of 0.15 and parallel pushing and pulling forces. The force transmission efficiency was 65.90 and 66.63% when the pushing force was 15° away from the pulling force on the sagittal and horizontal planes, respectively. The mandibular dentition moved mesially with agreater tendency for incisor labial crown tipping, mesial molar rotation and buccal second molar crown tipping when using the 8 mm hook compared to that when using the 2 mm hook. Rigid archwires resulted in more consistent tooth mesialization than stainless steel archwires. Asymmetric forces resulted in asymmetric dental arch mesialization. The forces transmitted by the presented mini-implant-supported device varied depending on the friction level and force direction. The device should be able to achieve symmetric or asymmetric total mesialization of the mandibular dentition.

Influence of maxillary first molar rotation on the severity of dental class II malocclusion: A cross-sectional study.

The aim of the study was to evaluate and assess the influence of maxillary molar rotation on severity of dental class II malocclusion. The study comprised of 4 different groups namely, 1/4th class II malocclusion, 2/4th class II malocclusion, 3/4th class II malocclusion and full class II malocclusion involving sample size of 20,15,16 and 12. The samples were subjected to digital evaluation of maxillary 1st permanent molar rotation using 4 parameters namely angle of Friel, Ricketts E-Line, angle of Henry and Premolar angle. The results were subjected to statistical analysis using one way ANOVA wherein group IV (Full class II malocclusion) exhibited a greater rotational value. On evaluation, angle of Friel exhibited a mean of 59.6±1.61 degrees, Ricketts E-Line was found to be 12.3±1.77mm while angle of Henry showed a mean of 19±3.19 degrees and premolar angle was 12.5±5.83 degrees. On evaluating molar rotation using angle of Friel, Ricketts E-Line, angle of Henry and premolar angle, full cusp class II malocclusion presented higher degree of mesiopalatal rotation maxillary molar rotation. With increasing mesiopalatal rotation, the severity of molar relation also increased from 1/4th to full class II. Hence the maxillary molar spatial position along the long axis majorly influences the molar relation wherein a full cusp class II molar relation exhibits higher degree of molar rotation.

Assessment of Maxillary First Molars Rotation in Class II malocclusion cases: A Cross Sectional Study

Introduction: Determination of malocclusion including individual tooth malposition is crucial during diagnosis and treatment planning. Along with anteroposterior mal-relation, there is often the rotation of upper first molars in Class II cases. Rotated molars not only occupy more space than normally positioned molars but also increase the challenge for orthodontic treatment. Aims and objectives: This study aimed to determine the prevalence and extent of maxillary molar rotation in Class II division 1 and 2 malocclusion cases. Material and Methods: A total of 142 pretreatment maxillary casts of Class II malocclusion (71 division 1 and 71 division 2) cases were collected from the Department of Orthodontics of People's Dental College and Hospital. All the casts were scanned at a 1 200 dpi resolution with teeth touching the glass of the scanner (brother MFC-L2700DW model). Scanned pictures were then printed without any change in magnification. Measurement was made on those printed copies of casts. To determine the rotation and its severity a method developed by Ricketts (Line of Ricketts) was used. Descriptive analysis was carried out in Microsoft Excel 2013. Result: In Class II division 1 cases, 45 (63.4%) had right molar rotation and 47 (66.2%) had left molar rotation. In Class II division 2 cases, 33 (46.5%) had right molar rotation while 34 (47.9%) had left molar rotation. Similarly, the mean rotations of the right and left molars in division 1 were 6.24 mm and 6.77 mm respectively and those in division 2 were 4.82 mm and 4.94 mm respectively. Conclusion: The prevalence and extent of rotation of maxillary molars in Class II divisions 1 and 2 malocclusion cases were assessed in this study. Mesiopalatal rotation and left molar rotation were observed more commonly in both divisions.

Comparing Distal-Jet with Dental Anchorage to Distal-Jet with Skeletal Anchorage: A Prospective Parallel Cohort Study.

The use of traditional intra-oral devices in maxillary molar distalization is not without undesirable consequences. The aim of the present study was to compare the miniscrew-supported distal-jet appliance to a traditional distal-jet appliance by evaluating the amount of upper first molar distalization and the dentoalveolar side effects. Data of 600 subjects visited at the orthodontic unit of Sapienza University of Rom were analyzed. Only 46 patients met the inclusion criteria and were selected and treated. Subjects were assigned randomly to receive treatment either with miniscrew-supported distal-jet appliance (Group A) or with a traditional distal-jet appliance (Group B). In Group A, miniscrews were inserted using a computer-guided surgical guide. The amount of upper first molar distalization and the dentoalveolar side effects were assessed both on the digital casts and on the lateral cephalometric radiograph at the end of the distalization phase. A descriptive statistical analysis that included the mean values and the standard deviation was conducted to evaluate the molar distalization and the dentoalveolar effects in two groups. Intergroup differences were determined using the Student’s t-test. The significance was set at p ≤ 0.05. In Group A, greater maxillary first molar distalization and a spontaneous distalization of the first premolars and a palatal inclination of central incisors were observed. By contrast, in Group B, the first premolars tipped mesially and a proclination of the maxillary central incisors was observed. In both groups, the transverse widths of the dental arch increased while a greater tendency of first premolar extrusion and of maxillary first molar rotation was observed in Group B. The skeletal anchorage device achieved greater first molar distalization and did not cause dento-alveolar side effects.

Torqued and conventional cantilever for uprighting mesially impacted molars: A 3-dimensional finite element analysis

The objective of this study was to evaluate the effects of the torqued cantilever (TC) and conventional tip-back cantilever (CC) made of stainless steel (SS) and titanium-molybdenum alloy (TMA) on the uprighting of mesially impacted mandibular molars using three-dimensional finite element analysis. The 3-dimensional mandibular model included part of the mandible with mesially tipped and impacted mandibular second molar, periodontal ligament (PDL), molar tube, mini-implant, and cantilevers. Four finite element method models (TC-SS, TC-TMA, CC-SS, and CC-TMA) were created to simulate different skeletally anchored uprighting mechanics. CC mechanics involved a known 0.019 × 0.025-in helical cantilever acting on a buccal molar tube. TC mechanics included a 0.019 × 0.025-in cantilever capable of producing mesial root torque by acting on a tube positioned on the molar disto-occlusal surface with the slot in a buccolingual direction. Three-dimensional molar displacement and stress distribution on the molar PDL were recorded. The SS cantilever produced almost twice as much molar displacement as the TMA. TC mechanics showed more evident mesial displacement of the molar root apexes. CC mechanics had greater molar rotation. TC uprighting moment produced greater molar mesial extrusion and greater intrusion of the distal root apex. The dual deflection system of the TC mechanics induced the lowest stress on the PDL, regardless of the metallic alloy. TC delivered a more efficient uprighting moment to the molar with less unwanted tooth movement and stress on the PDL and a more accessible site for bonding the molar tube.

Stability of the Maxillary and Mandibular Total Arch Distalization Using Temporary Anchorage Devices (TADs) in Adults

Distalization with temporary anchorage devices (TADs) is commonly used to resolve crowding and to correct molar relationships in non-extraction cases. The purpose of this study was to quantify the treatment effects and post-treatment stability of total arch distalization with TADs in adults and thereby elucidate the clinical effect of this treatment modality. The subjects of the study were 39 adult orthodontic patients treated with total arch distalization with TADs. Lateral cephalograms and dental casts were taken at pretreatment (T0), post-treatment (T1), and the retention period (T2, 29.3 ± 12.8 months) to evaluate the vertical and horizontal movement of teeth, changes of arch width and molar rotation. It was concluded that even though there was a little relapse in the anteroposterior position of the maxillary and mandibular teeth during retention, there was no obvious relapse in the facial profile. Therefore, the total arch distalization can be used in patients with a moderate amount of arch length discrepancy effectively with stable retention.

Clinical efficacy of open and close loops in retraction

Objective: To evaluate the clinical efficacy of open and closed loop during incisor retraction by comparing the rate of incisor retraction, the effect on incisors and anchorage unit.Materials and Methods: This clinical study included 24 participants treated with first bicuspid extraction which were randomly divided into two groups. Group I received Open tear drop loop and Group II received closed vertical shaped loop for space closure mechanics. The duration of the study was four months. Study models and lateral cephalograms were taken at the start (T0) and end of study period (T4).Results: Nasolabial angle increased significantly from T0 to T4 in the open loop group. The inter-canine width and arch length reduced more in open loop group. The rate of incisal retraction per day as calculated from arch length was more in open loop with 0.023 mm (0.0044), as compared with close loop 0.0194 mm (0.00475). The degree of molar rotation was more with open loop as compared with close loop.Conclusion: The pattern of space closure was different in both the groups. There was a more controlled retraction of incisors in the closed loop group with no incisor torque loss but slower rate of retraction Whereas, the open loop shows faster retraction but at the expense of molar rotation and reduction in inter-canine width.

Evaluation of maxillary first molar rotation during direct miniscrew-supported maxillary canine retraction: a before-and-after study

BackgroundExtraction of the first premolar followed by canine retraction into the extraction space is a common treatment in orthodontics. Molar rotation occurs when they are used as anchorage units for the canine distalization. The aim of this single-arm clinical trial was to evaluate the maxillary first molar rotation during maxillary canine retraction with elastic power chains and direct miniscrew anchorage.ResultsThe mean difference between pre-retraction and post-retraction molar rotation was 1.89° ± 0.6 which was statistically insignificant.ConclusionThe use of miniscrews for direct anchorage can eliminate unwanted rotation of the maxillary first molars during canine retraction.Trial registration ClinicalTrials.gov, NCT04887974. Registered on May 6, 2021- Retrospectively registered https://clinicaltrials.gov/ct2/show/NCT04887974?id=NCT04887974&draw=2&rank=1.

Synthesis and Biological Evaluation of Amino Acid Based Mutual Amide Prodrugs of Phenytoin as Anticonvulsant Agents.

Phenytoin (5,5-diphenyl hydantoin) has poor water solubility, which results in incomplete oral availability. Other problems associated with the oral and intramuscular administration of phenytoin are gastric irritation and inflammation at the site of injection. The purpose of this study was to synthesize mutual amide prodrugs of phenytoin by using amino acids like glycine, L-tryptophan, L-lysine and taurine. These prodrugs were synthesized and characterized by Fourier Transform Infrared (FTIR), Proton nuclear magnetic resonance (1H NMR) and Mass Spectra. Physical and spectral characterization was performed by determination of solubility, maximum wavelength, partition coefficient (log P), ionization constant (pKa), specific (α) and molar rotation (μ), refractive index (n), specific refraction (RS) and molar refraction (RM). The results obtained from solubility and log P values determination indicated that phenytoin prodrugs can be administered by oral as well as a parenteral route by minimizing the limitations associated with phenytoin. Anticonvulsant activity of prodrugs (4a-4d) was evaluated by using maximal electroshock (MES) and strychnine induced seizure test on albino mice of either sex weighing 25-30 g in which 4b and 4d were found to have significant anticonvulsant activity for MES and strychnine induced seizure test. In vitro enzymatic hydrolysis study of 4b and 4d was performed on liver, intestinal mucosa and plasma sample of male Sprague Dawley rats weighing 280-300 g in which phenytoin was eluted at 10.13 to 10.68 minutes at 220 nm. The results obtained from the present work showed that amino acid-based mutual prodrug strategy can be a promising method to increase the solubility and anticonvulsant activity of phenytoin for the development of anticonvulsant agents.

Effect of second molar eruption on efficiency of maxillary first molar distalization using Carriere distalizer appliance.

ABSTRACTIntroduction: Maxillary molar distalization is a common approach for correcting dental Class II malocclusions. Objective: This study aimed at comparing the outcomes of maxillary first molar distalization using the Carriere appliance before and after second molar eruption. Methods: Two groups of patients with dental Class II malocclusions were treated with Carriere distalizer appliance with heavy rectangular mandibular wire and lingual arch for anchorage. Patients of the first group presented unerupted maxillary second molars during the distalization period. In the second group, maxillary second molars were in occlusion on treatment onset. Cone beam computed tomography images were taken at the beginning of treatment and after finishing molar distalization, to compare both groups regarding first molar distalization, intrusion, mesiodistal tipping, buccolingual torquing and rotation, anchorage loss and skeletal changes. Also, the treatment durations were compared. Results: The mean first molar distalization period in the first group (19.2 ± 1.6 weeks) was significantly smaller than the second group (23.3 ± 2.3 weeks). The amount of maxillary first molar distalization was significantly greater, while the amount of rotation was significantly smaller in the first group. No statistically significant differences in the amounts of maxillary first molar intrusion, mesiodistal tipping and buccolingual torquing between both groups was found. Mandibular incisor labiolingual torquing and mandibular first molar mesialization and mesiodistal tipping were significantly greater in the second group. Conclusions: Maxillary first molar distalization before maxillary second molar eruption is more efficient, with less anchorage loss than after second molar eruption.

Modified Keles TPA –An Effective Method for Molar Derotation

Mesio-palatal rotation of maxillary 1st molars is commonly encountered in clinical practice and this results in a Class I molar relation becoming end on. Traditionally transpalatal arches (TPA) fabricated with 0.036” stainless steel wires have been used for correction of molar rotation in fixed orthodontic treatment. They are not very efficient in correcting the mesio-palatal rotations and require frequent activations. This article describes a modified Keles TPA as an easy, effective method for rapid and precise correction of unilateral or bilateral mesio-palatal molar rotations

Comparative Study of Two Maxillary Molar Distalization Appliances Using Different Anchorage Systems (An in Vitro Study)

Aims: This study aimed to compare the effects of two different anchorage systems for molar distalization. Materials and Methods: The sample consisted of two groups, Buccal Coil spring with Nance button as anchorage and Buccal Coil spring with simulated Screw as anchorage. Upper typodont arch of class II division I was used and the appliances were activated to deliver 200 gram of distalization force. Pre and postoperative digital images were taken and analyzed using Autodesk AutoCAD software™. For each group seven parameters were measured and compared. A significance value of 0.05 was predetermined. Results: Significant difference was found between the two groups in the vertical change, tipping change of the first molar, vertical change, mesial movement of the first premolar. Insignificant difference in first molar rotation, molar distalization rate and premolar tipping change. Conclusions: Maxillary molar distalization with minimal effects on anchoring teeth, molar tipping and vertical position change could be achieved with Buccal Coil spring with Screw distalization appliance.