Various methods of canine retraction in premolar extraction space: A case series

Following article is the review and presentation of various methodologies of canine retraction [e.g.– methods under sliding and friction less mechanics, facilitation with TADs (Temporary Anchorage Devices) and MOPs (Micro-Osteo-Perforations), and invasive procedures etc.] and comparison of these methods in terms of rate of canine retraction, and molar anchorage loss. Patient’s age ranges between 15y to 19y and only right maxillary canine was taken for comparison purpose.

Smart distalization of the upper arch with an easy, efficient and no-compliance procedure

In conventional Class II treatment, distalisation of the maxillary arch usually requires multiple phases of tooth movement during which anchorage loss can occur. In order to solve this issue, a rational and simple technique has been developed. Instead of using intraoral distalisers along with palatal mini-implants, Ni-Ti superelastic loops are used to obtain molar distalisation while buccal interradicular miniscrews (BIM), preferably placed between the roots of upper premolars, supply the necessary anchorage. Once the distalisation of molars and second premolars is performed, miniscrews are placed between the roots of first molars and second premolars after removing the previous miniscrews. Elastic chains or tie-backs, which go from the new miniscrews to the hooks of a 0.019×0.025-inch stainless-steel archwire, produce the retraction of incisors, canines and first premolars with optimal control of anchorage. Clinical cases are shown to illustrate the technique.

Stability of Dental Implants and Thickness of Cortical Bone: Clinical Research and Future Perspectives. A Systematic Review

Dental surgery implantation has become increasingly important among procedures that aim to rehabilitate edentulous patients to restore esthetics and the mastication ability. The optimal stability of dental implants is correlated primarily to the quality and quantity of bone. This systematic literature review describes clinical research focusing on the correlation between cortical bone thickness and primary/secondary stability of dental fixtures. To predict successful outcome of prosthetic treatment, quantification of bone density at the osteotomy site is, in general, taken into account, with little attention being paid to assessment of the thickness of cortical bone. Nevertheless, local variations in bone structure (including cortical thickness) could explain differences in clinical practice with regard to implantation success, marginal bone resorption or anchorage loss. Current knowledge is preliminarily detailed, while tentatively identifying which inconclusive or unexplored aspects merit further investigation.

Anchorage control using miniscrews in comparison to Essix appliance in treatment of postpubertal patients with Class II malocclusion using Carrière Motion Appliance:

ABSTRACT Objectives To evaluate anchorage control using miniscrews vs an Essix appliance in treatment of Class II malocclusion by distalization using the Carrière Motion Appliance (CMA). Materials and Methods Twenty-four postpubertal female patients with Class II, division 1 malocclusion were randomly distributed into two equal groups. CMA was bonded in both groups, and one group was treated with miniscrews as anchorage (12 patients, mean age = 18.0 years) while the other group was treated with an Essix appliance as anchorage (12 patients, mean age = 17.8 years). For each patient, two cone-beam computed tomographic scans were obtained: one preoperatively and another after completion of distalization. Results In the Essix appliance group, there was a statistically significant anterior movement (2.2 ± 1.43 mm) as well as proclination of the lower incisor (5.3° ± 4.0°), compared to a nonsignificant anterior movement (0.06 ± 1.45 mm) and proclination (0.86° ± 2.22°) in the miniscrew group. The amount of maxillary molar distalization was higher in the miniscrew group (2.57 ± 1.52 mm) than in the Essix appliance group (1.53 ± 1.11 mm); however, the difference was not statistically significant. Conclusions Miniscrews led to a decrease in the amount of anchorage loss in the mandibular incisors, both in terms of anterior movement and proclination.

Key Factors Contributing to the Anchorage Loss of Maxillary First Molars: A Retrospective Study of 726 Extraction Cases

Background: Anchorage control is one of the key components in the treatment of extraction cases. However, why anchorage loss happens is still an unanswered question. The purpose of this study was to investigate the most important factors contributing to the anchorage loss of maxillary first molars in premolar extraction cases. Methods：The study enrolled 726 upper premolar extraction cases, including 214 male patients and 512 female patients, and the average age was 14 (range: 9-45 years old).Factors including physiological characteristics, treatment mechanics and cephalometric variables were collected and their influences on the angulation changes of maxillary first molars were analyzed. Results: The average angulation change of maxillary first molar after treatment was 2.81°, meaning the molar tipped forward during treatment by 2.81°. The change of UM/PP showed statistically significant difference in different sex ( male 3.84°±5.26 ° vs female 2.38°±5.10°), age (adult -0.05°±4.73 ° vs teenager 3.46°±5.07°), and molar relationship(Class II 3.28°±5.15°vs Class I 2.36°±5.19°). There are six variables accounted in the regression analysis (R=0.608, R²=37.0%). Among them, the pre-treatment molar tipping (Standardized Coefficients：-0.65) and the pre-treatment incisor/molar height ratio (Standardized Coefficients：-0.27)were the most important factors influencing anchorage loss during treatment.Conclusion: Compared with treatment-related factors, the patient’s physiological characteristics play a more important role in anchorage loss. The pre-treatment angulation of the maxillary first molar is the most contributing factor of the maxillary molar angulation changes, which are often predisposing anchorage loss.

Efficiency of the skeletonized Pendulum K appliance for non-compliance maxillary molar distalization

Purpose Conventional anchorage with exclusively intraorally anchored appliances for non-compliance molar distalization combines a palatal acrylic button with periodontal anchorage. This type of anchorage is critically discussed because of the temporary hygienic impairment of the palate and the uncertain anchoring quality of the button. A purely dentally/periodontally anchored Pendulum K appliance was developed, which is exclusively anchored via four occlusal rests. The aims of this pilot study were to examine the suitability of the skeletonized Pendulum K for distalization of maxillary molars, and to investigate the quality of this alternative anchoring modality. Patients and methods In all, 10 patients received skeletonized Pendulum K appliances attached to all maxillary premolars for bilateral molar distalization. Supporting anchorage through an acrylic button adjacent to the anterior palate was not used. The pendulum springs were initially activated on both sides with a distalization force of 220 cN each and provided with uprighting and toe-in bends. The specific force/moment system was regularly reactivated intraorally by adjustment of the distal screw. Results The study demonstrates the suitability of the skeletonized Pendulum K appliance for the distalization of maxillary molars (3.28 ± 0.73 mm). Side effects on the molars were slight distal tipping (3.50 ± 2.51°/PP, 3.00 ± 1.41°/SN) and mesial inward rotation (average 2.75 ± 7.50° and 4.50 ± 12.77°). Significant anchorage loss occurred in the form of mesialization of the incisors by 1.40 ± 0.82 mm and of the first premolars by 2.28 ± 0.85 mm. Conclusion The skeletonized Pendulum K appliance allows compliance-free upper molar distalization. Exclusively dental/periodontal anchorage resulted in a lower percentage of molar distalization compared to a conventional anchoring preparation of the Pendulum K with a palatal acrylic button. Anchorage loss had a comparatively stronger effect on the anchoring premolars but less on the incisors. Typical side effects on the molars such as distal tipping and mesial inward rotation were remarkably low.

The effectiveness of surgical adjunctive procedures in the acceleration of orthodontic tooth movement: A systematic review of systematic reviews and meta-analysis

Objective: To identify and evaluate the body of the evidence regarding the effectiveness of surgical adjunctive procedures (SAPs) in accelerating orthodontic tooth movement (OTM). Data sources: Unrestricted search of three electronic databases and manual search up to 12 June 2020 were undertaken. Data selection: All systematic reviews of randomised and non-randomised controlled trials that investigate the effectiveness of the SAPs in accelerating OTM were included. Data extraction: Study selection and data extraction were undertaken independently and in duplicate by two reviewers. A random-effects model with a 95% confidence interval (CI) was generated for comparable outcomes. Two reviewers assessed the quality of the included studies using AMSTAR2 and GRADE. Results: Fourteen systematic reviews were included; however, four systematic reviews were assessed quantitatively. Meta-analysis showed that mean difference (MD) of canine retraction rate, for the first month after SAPs, was mild (MD = 0.65 mm/month). Compared to control, micro-osteoperforations (MOPs) statistically but temporally accelerate lower canine retraction and en masse retraction by 0.25 mm/month and 0.31 mm/month, respectively. There was no significant effect ( P>0.05) in terms of molar anchorage loss (MAL) between control and MOP groups. Piezocision non-significantly shortens the duration of en masse retraction (4.30 months, P>0.05), but significantly shortens incisors retraction (101.64 days, P<0.001). MAL is mild but significantly less in the piezocision group compared to the control group (MD = 0.53 mm, P=0.03). Low-level evidence showed that SAPs have no significant effect on root resorption or periodontal health; however, piezocision is associated with transient acute inflammation and noticeable scars. Conclusion: Low-level evidence concludes that SAPs accelerate OTMs and reduce treatment duration, but the acceleration is minor and transient. The effect on anchorage loss is variable and technique related. Side effects of SAPs are transient, but some might be aesthetically noticeable. A cost-benefit analysis of SAPs should be considered while making the treatment decision.

Key Factors Contributing to The Anchorage Loss of Maxillary First Molars: A Retrospective Study of 726 Extraction Cases

Background: Anchorage control is one of the key components in the treatment of extraction cases. However, why anchorage loss happens is still an unanswered question. The purpose of this study was to investigate the most important factors contributing to the anchorage loss of maxillary first molars in premolar extraction cases. The study enrolled 726 upper premolar extraction cases, including 214 male patients and 512 female patients, and the average age was 14 (range: 9-45 years old).Factors including physiological characteristics, treatment mechanics and cephalometric variables were collected and their influences on the angulation changes of maxillary first molars were analyzed. Results: The average angulation change of maxillary first molar after treatment was 2.81°, meaning the molar tipped forward during treatment by 2.81°. The change of UM/PP showed statistically significant difference in different sex ( male 3.84°±5.26 ° vs female 2.38°±5.10°), age (adult -0.05°±4.73 ° vs teenager 3.46°±5.07°), and molar relationship(Class II 3.28°±5.15°vs Class I 2.36°±5.19°). There are six variables accounted in the regression analysis (R=0.608, R²=37.0%). Among them, the pre-treatment molar tipping (Standardized Coefficients：-0.65) and the pre-treatment incisor/molar height ratio (Standardized Coefficients：-0.27)were the most important factors influencing anchorage loss during treatment.Conclusion: Compared with treatment-related factors, the patient’s physiological characteristics play a more important role in anchorage loss. The pre-treatment angulation of the maxillary first molar is the most contributing factor of the maxillary molar angulation changes, which are often predisposing anchorage loss.