Premolar Extraction Research Articles

Effect of leukocyte platelet-rich fibrin on the rate of canine movement – A prospective and randomized control trial

Objectives: The present study was conducted to investigate the effects of leukocyte and platelet-rich fibrin (L-PRF) on the rate of maxillary canine retraction for a period of 5 months. Material and Methods: A split-mouth study was conducted on 16 patients (32 extraction sockets) (Nine males and seven females; age ranging 17–25 years) with Class II Div 1 malocclusion or Class I bimaxillary protrusion, requiring therapeutic extraction of bilateral maxillary first premolars. After the initial leveling and alignment, L-PRF plugs were placed immediately in the randomly selected socket (Experimental Group) and the other side served as control for secondary healing (Control Group). This was followed by the activation of nickel-titanium closed coil springs for canine retraction. The rate of canine movement, canine rotation, tipping, root resorption, and molar movement was assessed at monthly intervals for 5 months (T0–T5). Data were collected from study models. Assessment of pain accompanying the procedure was done using a Likert scale. The trial was registered at the Clinical Trials Registry of India (REF/2022/02/051837). Results: The study revealed that there was a significant increase in the rate of canine movement on the experimental side in the first 2 months and significant molar anchorage loss was seen only in the 1st month. There were statistically non-significant differences in canine rotation, tipping, probing depth, root resorption, and pain perception between the groups. Conclusion: The use of L-PRF plugs in the extraction sockets enhanced the rate of canine movement in the first 2 months of treatment with less anchorage loss and no deleterious effects on periodontium.

Evaluation of the Effect of Oral Vitamin D3 Supplement on Orthodontic Tooth Movement: A Randomized Clinical Trial Study

Aim: One of the problems that orthodontists commonly face is the prolonged duration of the treatment. Therefore, it is important to find an effective method to increase the rate of orthodontic tooth movement (OTM). This study aimed to evaluate the effectiveness of oral administration of vitamin D3 on OTM rates in humans. Materials and Methods: In this randomized clinical trial study, we selected 29 healthy women aged 18–25 years who sought orthodontic treatment and required bilateral maxillary first premolar extraction. Participants were tested to measure the blood levels of vitamin D3 and, based on the outcomes, were divided into three groups: control (without vitamin D3 deficiency; N = 10), placebo ( N = 9), and experiment ( N = 10), both with vitamin D3 deficiency. Subjects of the last two groups, who were randomly assigned, received 50,000 IU (International Unit) vitamin D3 pearls (Dana Pharmaceutical Company, Tabriz, Iran) or a placebo every 2 weeks for 2 months. Inclusion criteria were patients requiring bilateral extraction of the first premolar in the maxilla. The canines were retracted by nickel-titanium (NiTi) coil springs into the extraction sites. At the beginning, after 1 and 2 months, the distance between canine and lateral teeth on both sides was measured to calculate OTM. Results: In the first month ( t (1–2)), the mean values of OTM in the placebo group were higher than the other groups. However, during the second month ( t (2–3)) and overall ( t (1–3)), the experiment group showed a higher OTM. The experiment and control groups were statistically different in all three time periods ( P-value < .05). The difference between the experiment and placebo groups was only significant in t (2–3) ( P-value < .05). Whereas the placebo and control groups showed a significant difference in t (1–2) ( P-value < .05). Conclusion: Vitamin D3 deficiency seems to increase OTM. Receiving oral supplements of vitamin D3 may not have much effect on increasing the level of vitamin D3. The lowest OTM rate was observed in the control group.

Relationship between the amount of mesial movement of the mandibular first molar and angular changes of the mandibular third molar: A retrospective comparative study in growing patients with and without first premolar extraction

The main objective of this study was to assess the relationship of the amount of mesial movement of mandibular first molar (MFM) and angular changes of the mandibular third molar (MTM) in orthodontic patients. The secondary objective of this study was to compare the obtained values in extraction and non-extraction orthodontic patients. In this cross-sectional retrospective study were enrolled all the eligible patients (12-16 years) with and without first premolar extraction that met the inclusion criteria. The angle between the longitudinal axis of MTM and horizontal reference plane (HRP) (to calculate the angular change of MTM), and the distance between the cementoenamel junction of the mesial surface of MFM and the bisector of the anterior nasal spine and nasal septum (to determine the amount of mesial movement of MFM) were measured on pre- and post-treatment panoramic radiographs. The correlation between the two variables was analysed and compared between extraction and non-extraction patients using STATA v. 14.2 software. A total of 100 fixed orthodontic patients with and without first premolar extraction (n=50) whose treatment had been accomplished were included in the study. In the non-extraction group, the mean amount of mesial movement of MFM was 1.45mm and the mean angular change of MTM was 4.28 degrees; this correlation was significant (P<0.05). These values were 2.98mm and 7.17 degrees in the first premolar extraction group, respectively, with a significant correlation (P<0.05). However, the difference in this respect was not significant between the two groups (P>0.05). According to the regression model, 1mm mesial movement of MFM would averagely cause 2.2-degree angular change in MTM, adjusting for the effect of extraction/non-extraction treatment plan. The mesial movement of MFM was significantly correlated with the angular changes of MTM in extraction and non-extraction orthodontic patients, with no significant difference between them.

A Split-Mouth Clinical Comparative Evaluation of the Anesthetic Efficacy of Articaine and Lignocaine for Maxillary Bicuspids Extraction.

Aim The study compared the anesthetic effectiveness of articaine and lignocaine when premolars are extracted bilaterally for orthodontic purposes. Material and methods This prospective split-mouth study was performed on 30 cases selected from orthodontic referral patients reporting to the Oral and Maxillofacial Surgery Department at Maharaja Ganga Singh Dental College and Research Center, Rajasthan, India, for bilateral extraction of premolars under local anesthesia. We used 4% articaine hydrochloride and adrenaline 1:100000 (AH) as group A and 2% lignocaine hydrochloride with adrenaline 1:100000 (LH) on the control side as group B. For premolar anesthetization, 0.6-1.6 ml of AH and 1-2 ml of LH were injected submucosally in the buccal vestibular area. The extraction procedure was then carried out after achieving adequate anesthesia. The pain was assessed with Visual Analog Scale. The average onset time and duration of anesthesia were recorded. Data collected were summarized with descriptive statistics.The SPSSversion 23.0 (IBM Corp., Armonk, New York) was used for data entry, validation, and analysis. Means of continuous variables were compared using the student t-test. All tests were 2-tailed and significant at equal or less than 0.05. (p≤0.05). Results When comparing the overall anesthetic efficiency, Group A had a lower overall pain score of 0.43 while Group B had a higher overall pain score of 2.9. The average onset time of anesthesia in Group A was 1.2 minutes and 2.55 minutes in Group B. In Group A, the average duration of anesthesia was 70 minutes, and 46.5 minutes in Group B. These parameters were statistically significant with a p-value of <0.05. Conclusion The study concluded that as an alternative to lignocaine, articaine could be used effectively for maxillary premolar extractions for orthodontic reasons obviating palatal injection which is very painful to the patient.

Asymmetric Extraction Decision in Orthodontics.

During the treatment planning process, extraction decisions are crucial. As a therapy option, the extraction of teeth should be considered in instances where there is a lack of facial harmony and stability in the occlusion. Treatment aims, the kind of malocclusion, aesthetic considerations, and growth patterns are all factors that influence asymmetric extraction. For the most part, premolar extractions are required when there is a significant midline difference or an asymmetrical connection between the teeth. Premolars, which are the first teeth to erupt and occupy the posterior position in chewing, are more vulnerable to injury than other permanent teeth. The optimal time to remove a second molar is at the moment when the connection between the molars has normalized or when a major front cross-bite can be remedied.

Evaluation of pharyngeal airway space after orthodontic extraction treatment in class II malocclusion integrating with the subjective sleep quality assessment

Orthodontic treatment with premolar extractions is typically used to relieve dental crowding and retract anterior teeth for lip profile improvement. The aim of the study is to compare the changes in regional pharyngeal airway space (PAS) after orthodontic treatment with Class II malocclusion and to identify the correlations between questionnaire results and PAS dimensions after orthodontic treatment. In this retrospective cohort study, 79 consecutive patients were divided into normodivergent nonextraction, normodivergent extraction, and hyperdivergent extraction groups. Serial lateral cephalograms were used to evaluate the patients’ PASs and hyoid bone positions. The Pittsburgh Sleep Quality Index and STOP-Bang questionnaire were used for sleep quality evaluation and obstructive sleep apnea (OSA) risk assessment, respectively, after treatment. The greatest airway reduction was observed in hyperdivergent extraction group. However, the changes in PAS and hyoid positions did not differ significantly among three groups. According to questionnaire results, all three groups had high sleep quality and low risk of OSA, with no significant intergroup differences. Moreover, pretreatment-to-posttreatment changes in PAS were not correlated with sleep quality or risk of OSA. Orthodontic retraction with premolar extractions nither exhibit significant reduction in airway dimensions nor increase their risk of OSA.

Labial and Palatal Pressure Changes in Extraction Cases Before and After Maxillary Incisor Retraction: A Quasi-Experimental Study.

To evaluate the changes in lip and tongue pressure before and after incisor retraction in patients undergoing orthodontic treatment with premolar extraction and incisor retraction. A Quasi-experimental study Place and Duration of the Study: Orthodontic Department at Dow University of Health Sciences, Pakistan, from January 2018 to November 2019. The study included 64 patients who were divided into two groups, (32 patients of class I and 32 patients of class II malocclusion). The lip and tongue pressures were recorded before and after incisor retraction with the help of Flexiforce sensor. The collected data were statistically analysed using the SPSS V-24 software. Shapiro-Wilk test was used to test the normality of data. The mean difference between lip and tongue pressure before and after incisor retraction was analyzed by Wilcoxon Signed Ranks Test. The difference in soft tissue pressures between class I and class II treatment groups was carried out using the Mann Whitney test. The mean pressure on the labial surface of incisors was significantly reduced after premolar extraction and incisor retraction (p ≤0.001). On the other hand tongue pressure on the palatal side of incisors was enhanced after incisor retraction (p=0.008) Comparing the differences between Angle's class I and class II malocclusion in mean pressure changes before and after incisor retraction revealed that the difference was not statistically significant on labial (p=0.58) or palatal side (p=0.28) of maxillary incisors. Reduced lip pressure and increased tongue pressure were observed after incisor retraction, whereas no significant change was seen in between the class I and class II cases. This signifies that orthodontic extraction affects the pressure changes on incisors and teeth do not remain in balance equilibrium at rest. Lip pressure, Tongue pressure, Orthodontic treatment, Flexiforce resistive sensor, Extraction, neutral zone.

Corrective orthodontic treatment of high Frankfort mandibular plane angle with maxillary expansion and four premolar extractions with presence of external apical root resorption during treatment

This case report describes the orthodontic treatment performed on a 10-year-old female patient in mixed dentition stage who presented with maxillary constriction that was associated with Angle Class III malocclusion, severe crowding, and high mandibular plane angle. She had the main complaint of an unaesthetic smile. The rapid maxillary expansion approach was chosen, followed by four first premolars extraction with fixed appliance. Two mandibular miniscrews were used for anchorage control and 0.018 × 0.025-in beta titanium advance archwire were used to increase labial tipping of the maxillary incisors. After 3 years, favorable results were achieved for the occlusion, dental aesthetics, and facial profile. External apical root resorption was noted in the maxillary incisors. The patient's self-esteem improved. Treatment results were stable after 1-year follow-up.

Effects of vertical control on anatomic and aerodynamic characteristics of the oropharyngeal airway during premolar extraction treatment of Class II hyperdivergent nonsevere crowding malocclusion

This study aimed to analyze the effects of premolar extraction treatment with vertical control on changes in the anatomy and aerodynamics of the oropharynx in Class II hyperdivergent malocclusion with nonsevere crowding. Thirty-nine patients with Class II hyperdivergent malocclusion were enrolled consecutively. All the participants underwent 4 premolar extractions. The high-pull J-hook and mini-implants were used to provide vertical control. Cone-beam computed tomography was performed before and after treatment. The participants were divided into a decreased lower vertical facial height group (n= 23) and an increased lower vertical facial height group (n= 16) on the basis of superimposition. The aerodynamic characteristics, including airway resistance (inspiration, Rin; expiration, Rex) and maximum velocity (inspiration, Vmaxin; expiration, Vmaxex) at inspiration and expiration, were calculated using computational fluid dynamics. Anatomic characteristics, including volume and cross-sectional area (CSAmin), were measured using the Dolphin Imaging software (Dolphin Imaging and Management Solutions, Chatsworth, Calif). After treatment, the median volume and CSAmin increased by 2357 mm3 and 43 mm2, respectively, and median Rin and Vmaxex decreased by 0.15 Pa/L/min and 0.24 m×s-1, respectively, in decreased lower vertical facial height group. In contrast, the median CSAmin decreased by 9.5 mm2 in the increased lower vertical facial height group. All the changes were statistically significant (all P<0.05). Significant differences in volume, CSAmin, Rin, and Vmaxex were observed between the 2 groups. Vertical control might improve the anatomic and aerodynamic characteristics of the oropharyngeal airway during premolar extraction treatment of Class II hyperdivergent malocclusion with nonsevere crowding.

Pulp Vitality of Orthodontic Retracted Canine Using Two Approaches of Periodontal Distraction: A Comparative Clinical Study

Objectives: All studies performed periodontal distraction with interseptal bone cuts but no one performed it without interseptal bone cuts. Therefore the aim of the present study was to evaluate and compare the effect of periodontal distractor with and without interseptal bone cuts on the pulp vitality of the retracted canines. Methods: The sample of the study consisted of 32 canines in 16 female patients (16- 21 years old) requiring extraction of bilateral maxillary first premolars and canine retraction. They were divided into two groups: canine retraction by periodontal distractor with distal interseptal bone cuts (Group I), canine retraction by periodontal distractor without distal interseptal bone cuts (Group II). After bilateral maxillary premolar extraction in both groups inter septal bone cuts was done in group I only. Then the periodontal distractor was cemented and activated twice per day in both groups. An electrical vitality test was evaluated before and after the distraction procedure. Results: None of the teeth reacted negatively to the electrical vitality test that was performed one month after the completion of the distraction procedure. There was no clinical sign of discoloration or pulpal pain in any tooth. Conclusions: Canine retraction was accelerated effectively by periodontal distraction technique either with or without distal interseptal bone cuts. The electrical pulp tester was positive in both groups.

A Novel Method to Accelerate Orthodontic Tooth Movement Using Low-Intensity Direct Electrical Current in Patients Requiring en-Masse Retraction of the Upper Anterior Teeth: A Preliminary Clinical Report.

Shortening the duration of orthodontic treatment by speeding up the rate of tooth movement has become an essential goal for both orthodontists and patients. This preliminary report aimed to investigate the safety and effectiveness of a new intraoral removable electrical device in accelerating the en-masse retraction of the upper anterior teeth using low-intensity direct electrical current. This prospective preliminary interventional clinical study was conducted at the Department of Orthodontics, Faculty of Dentistry, Damascus University, Syria, between March 2019 and February 2020. The sample consisted of six patients (four females and two males; mean age: 19.55 ± 0.89 years) whose initial diagnosis was class II division I malocclusion, and their treatment plansuggested the extraction of upper first premolars followed by en-masse retraction. The electrical stimulation was applied on the maxillary anterior region during the en-masse retraction phase using a specially fabricated removable device that was designed by two coauthors of this manuscript (RIS, MYH). Patients were asked to wear their own electrical devices inside their mouths for five hours daily. The primary outcomes were the en-masse retraction rate and duration. The secondary outcomes were safety and patient acceptance. The average total retraction rate during the treatment period was 0.97±0.06 mm/month. The total amount of retraction achieved during follow-up was 5.65 ± 0.85 mm, which was about 91.86% of the space resulting from the extraction of the upper first premolars. The mean treatment duration to complete the en-masse retraction was 5.66±0.81 months. No side effects of the electrical stimulation were found during the follow-up. Low-intensity direct electrical current could be an effective method to accelerate orthodontic movement. The electrical accelerating device used in this study effectively increased the en-masse retraction rate of the upper anterior teeth without any side effects and with high patient acceptance.

Evaluation Of The Effectiveness Of Combined Photobiomodulation And Piezocision On the Rate Of Orthodontic Tooth Movement. A Randomized Control Trial.

Aim: To assess and compare the efficiency of tooth movement in patients subjected to piezocision and photobiomodulation as part of a split-mouth clinical experiment, and to combine their effects in order to derive a synergetic effect if any. Methods: 24 subjects requiring bilateral first premolar extractions were selected for the study. The study had a split mouth design with patients subjected to either piezocision, photobiomodulation or a combination of the two techniques in one quadrant and the opposite quadrant served as the control. Piezocision was carried out by placing vertical interproximal incisions on the mesiobuccal and distobuccal aspect of the maxillary canine, whereas photobiomodulation was carried out at ten sites, five on the buccal aspect and five on the palatal aspect with a total energy of 10J in the period between the three weeks. Results: There was no statistically significant difference observed in terms of accelerated tooth movement between piezocision, photobiomodulation or combination of the two techniques and the conventional technique. Conclusion: Although no statistically significant findings were derived, a synergistic effect was observed with the combined effect of piezocision and photobiomodulation showing an enhanced effect. Increased rate of tooth movements were observed in both piezocision and photobiomodulation group with lowest effect seen in the photobiomodulation group. Bangladesh Journal of Medical Science Vol.22 (Special Issue) 2023 p.138-147

Everybody gets an expander

Seemingly every preadolescent patient that presents for an orthodontic consultation is prescribed rapid maxillary expansion (RME) treatment. Parents are forewarned of premolar extractions, lateral incisor root resorption from ectopic canines, or obstructive sleep apnea if they delay treatment. Are we exaggerating the need for Phase I RME in pursuit of two-phase treatment and increased revenue? Let's take a closer look at the history, trends, expectations, and proper timing of RME, with an emphasis on Phase I treatment.

Changes in the Vertical Dimension After Orthodontic Treatment in Response to Different Premolar Extraction Patterns.

Premolar extractions in orthodontics can relieve dental crowding and affect incisor inclination. The aim of this retrospective study was to compare changes to the facial vertical dimension after orthodontic treatment with different premolar extraction patterns and non-extraction treatment. This was a retrospective cohort study. The pre-and post-treatment records of patients with at least 5.0mm of dental arch crowding were accessed. Patients were divided into three groups: Group A, patients who had four first premolars extracted during their orthodontic treatment; Group B, patients who had four second premolars extracted during their orthodontic treatment; and Group C, patients with no extractions during orthodontic treatment. The pre-and post-treatment skeletal vertical dimension measured through the mandibular plane angle, as well as the incisor angulations/positions, were measured on lateral cephalograms and compared between groups. Descriptive statistics were computed and statistical significance was set at p<0.05. A one-way ANOVA test was conducted between groups to assess for statistically significant differences in changes to the mandibular plane angle and incisor positions/angulations. Post-hoc statistical analyses were performed between groups for parameters showing significant differences. One-hundred twenty-one patients were included (47 males and 74 females) with ages ranging from 9 years old to 26 years old. Mean upper dental crowding ranged from 6.0 to 7.3mm and mean lower crowding ranged from 5.9-7.4mm across groups. There were no significant differences in mean age, mean treatment length, or mean dental arch crowding in each arch across groups. There were no significant differences in changes to the mandibular plane angle across all three groups regardless of the extraction pattern or non-extraction during orthodontic treatment. The upper and lower incisors were significantly retracted in groups A and B and significantly protracted in group C post-treatment. The upper incisors retroclined significantly more in Group A than Group Band proclined significantly in Group C. No differences in the vertical dimension and the mandibular plane angle were observed when extracting first versus second premolars and in non-extraction treatment. Significant changes to the incisor inclinations/position were observed depending on the extraction/non-extraction pattern executed. Different premolar extraction patterns during orthodontic treatment do not influence changes to the vertical dimension. Clinicians should make extraction decisions based on desired outcomes for incisors rather than controlling the vertical dimension.

Autotransplanation of immature premolars to replace a severely traumatized maxillary central incisor in young patients: Orthodontic and surgical cooperation

Young patients with a severely traumatized maxillary central incisor have limited possibilities to restore its loss. Autotransplantation of immature premolars has been documented as a predictable long-term outcome with the potential for preservation and regeneration of alveolar bone. They can also be successfully reshaped to the central incisor's morphology using direct composite build-ups. However, tooth transplantation is a technique sensitive procedure and requires good case selection, an understanding of relevant tooth transplantation biological principles and careful execution of the optimal surgical and follow-up protocols. Orthodontists play an important role in cooperation with the surgeon before and after surgery. This includes selection of suitable candidates based on orthodontic evaluation of occlusion and indications for premolar extraction, opening adequate space before transplantation and post-surgical alignment of the transplant for an optimal reshaping and establishing a stable occlusion. The aim of the paper is to present clinical application of autotransplanation of immature premolars to replace a traumatized central incisor in growing patients and to discuss the role of an orthodontist in the interdisciplinary team.

Third molar position after completion of orthodontic treatment: a prospective follow-up.

To prospectively follow up a previously reported sample, analyzing (1) changes in third molar (M3) position after completion of 2 different types of orthodontic treatment: (2) non-extraction treatment with (HG) vs without cervical headgear (non-HG) and (3) first or second premolar extractions (PM1-2) compared to a non-extraction group (NE). A total of 474 patients were prospectively followed up. Panoramic radiographs were taken pre- (T1), post-treatment (T2) and at follow-up (T3). T3 records (a mean of three years after treatment) were available for 135 (HG vs non-HG) and 134 patients (PM1-2 vs NE), respectively. Angulation, vertical position, relation with the mandibular canal and mineralization status of M3 at T2 and T3 were statistically compared. The HG group presented more M3 with ideal vertical orientation at T3. In NE-cases, further improvement in angulation and orientation can be expected after debonding, as well as a deterioration in the relationship with the mandibular canal. Extractions accelerated upper M3 vertical eruption and PM2 extractions led to long-term larger lower retromolar spaces. The use of cervical headgear increased upper M3 uprighting three years after debonding, while little changes in M3 position were found after orthodontic treatment with extractions. However, PM2 extractions led to larger retromolar spaces and better M3 angulation in the long term.

Class III Malocclusion Camouflage Treatment Using a Conventional Orthodontic Appliance in a Non-Growing Patient

The treatment of skeletal and dental Class III malocclusions is a challenge for orthodontists, and one of the treatment alternatives for a non-growing patient is orthodontic camouflage treatment. Different approaches may result in different outcomes; therefore, a proper diagnosis and treatment plan are needed to avoid undesirable effects. In this case, a 21-year-old female patient presented with a skeletal Class III malocclusion, with a normal maxilla, prognathic mandible, moderate crowding, and an acceptable facial profile. The treatment modality for orthodontic camouflage treatment was a conventional orthodontic appliance with the extraction of mandibular first premolars to resolve crowding. At the end of the treatment, a Class I canine and incisor relationship was achieved while maintaining a Class III molar relationship. After 25 months of treatment, the patient had a more pleasant smile with improved functional occlusion.

Effect of three different maxillary expansion appliances on root resorption

Aim: The study was to examine rapid maxillary expansion (RME), semi-rapid maxillary expansion (SRME), and slow maxillary expansion (SME) compare the root resorptions occurring in the supporting upper first premolar teeth during treatment by using micro-computed tomography (micro-CT). Methodology: Thirty individuals that required maxillary expansion and upper first premolar tooth extraction were divided into three groups consisting of 10 individuals for RME, SRME, and SME. RME group, first premolar and first molar teeth with hyrax screw were activated ¼ tour twice daily with the banded hyrax appliances. SRME group, acrylic-bonded hyrax appliances were activated ¼ tour per morning and night until the opening of the suture. Upon the opening of the suture, it was activated ¼ tour per every two days until sufficient maxillary expansion was gained. SEM group, quad helix appliances were activated every 20 days. After 12 weeks of the retention period, the upper first premolar teeth were extracted. The teeth were scanned with Micro-CT (SkyScan 1172, Kontich, Belgium), and images were analyzed with a Dell Precision T5500 to determine the resorption crater volumes. Results: In all samples, the resorption craters were concentrated on the buccal surfaces of the tooth roots. The highest resorption craters volume, the total resorption volume, was observed in the RME group, followed by the SRME group, and the least resorption crater volume was detected in the SME group. Conclusion: Since the supporting teeth were exposed to more force on the root surfaces, the most resorption was seen in the RME group. How to cite this article: Topal R, Gündüz Arslan S. Effect of three different maxillary expansion appliances on root resorption. Int Dent Res 2023; 13(1):19-26. https://doi.org/10.5577/idr.2023.vol13.no1.4 Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

CBCT evaluation of apical root resorption in maxillary and mandibular anterior teeth in orthodontic patients

Introduction: One of the drawbacks of getting braces is root resorption. CBCT's high spatial resolution makes it a useful tool for gauging the extent to which external root resorption has occurred. Aim: Patients with bimaxillary protrusion receiving fixed orthodontic therapy will have CBCT scans taken of their upper and lower anterior teeth to check the degree of apical root re-sorption. Materials and Methods: This article focuses on retrospective data of 15 patients with dento-alveolar protrusion treated with all initial premolar extraction and fixed orthodontic mechanotherapy. Each patient had pretreatment &amp; post-retraction CBCT scans of upper and lower anteriors which were compared to measure changes in root length, root volume and root apex displacement. Results: Mean root length of maxillary and mandibular anteriors showed significant difference from pre-treatment to post-retraction. The root volume of maxillary anteriors and mandibular anteriors except for the root volume of mandibular lateral incisor showed statistically significantly decrease at post-retraction. Angular mean root apex displacement of canine and mandibular &amp; maxillary central incisor, also lateral incisor showed significant differences from pre-treatment to post-retraction. Conclusion: Roots of teeth can be altered with orthodontic therapy. After retraction, there was a decrease in root length in root volume, although these alterations were within a clinically feasible range.

Treatment Effectiveness of Clear Aligners in Correcting Complicated and Severe Malocclusion Cases Compared to Fixed Orthodontic Appliances: A Systematic Review.

This systematic review aimed to critically assess the available evidence regarding the effectiveness and efficiency of clear aligners in the comprehensive treatment of complex cases accompanied by premolars extraction. An electronic literature search by two reviewers was independently done on 27 February 2023 in the following databases without time and language limitations: Pubmed®, Scoups®, Google Scholar, Cochrane Library database, Web of Science™, and Proquest Database Open. Randomized controlled trials (RCTs) of any type, non-randomized clinical trials (CCT), cohort studies, and prospective, retrospective, and cross-sectional studies were reviewed. The risk of bias in included studies was assessed using the Risk of Bias (RoB 2.0) tool for randomized trials and the Risk of Bias in Non-randomized Studies (ROBINS-I) tool for non-randomized studies. After carefully searching the literature, six trials were included in this systematic review, three RCTs, two retrospective cohort studies, and one CCT. Two hundred eighty-three patients were included (186 females, 97 males). Three studies found that there were no differences between the clear aligners and fixed appliances when evaluations were done using the American Board of Orthodontists Objective Grading System (ABO-OGS) or the Peer Assessment Rating (PAR) index. Two studies found that there were some differences between predicted and achieved tooth movements when clear aligners were used in premolars extraction cases. Based on the included studies, the duration of treatment was shorter with fixed appliances than the clear aligners when applied to orthodontic extraction cases. Both clear aligners and fixed appliances were found effective in the orthodontic treatment of premolar extraction-based cases. Fixed appliances have the advantage of achieving better buccolingual inclination and occlusal contacts in a shorter treatment duration. Treatment with clear aligners might be associated with differences between predicted and achieved tooth movements. Therefore, the characteristics of these techniques should be considered when making a treatment decision.