Undesired Tooth Movement Research Articles

Exploring different methods for assessing anchorage loss during orthodontic space closure: A narrative review

ABSTRACT To ensure successful treatment and to prevent undesired tooth movements, it’s essential to manage reciprocal forces effectively. Anchorage control becomes particularly crucial in cases involving extractions, where it can help prevent unwanted tooth movement. However, during treatment, there’s a risk of anchorage loss, which can undermine the treatment objectives. Therefore, it’s imperative to monitor molar movement and assess for anchorage loss throughout treatment. Research publications were searched on search engines such as Scopus, PubMed, and Google Scholar, and articles with terms such as “anchorage management, assessment of anchorage loss, anchorage loss, space closure , en masse retraction and canine retraction” were collected. Various methods for evaluating anchorage loss are dental casts, 3-Dimensional assessment and lateral cephalogram superimposition. Dental casts works well for assessing anteroposterior anchorage loss in maxillary first molars. However, their utility in the mandibular arch is limited due to the absence of a stable reference point. Lateral cephalometry faces the challenge of superimposing bilateral structures. The recent introduction of 3D superimposition techniques offers a potential solution for assessing anchorage loss in the vertical dimension using dental casts.

Three-dimensional microanalysis of tooth movement during the first 6 months of orthodontic double retention

This study performed a 3-dimensional analysis of tooth movement during orthodontic retention to assess the effectiveness of double retention (fixed and removable) in preventing undesired tooth movement. One hundred randomly selected patients were included at the initiation of double orthodontic retention with fixed retainers and vacuum-formed splints (recommended to be worn 22 h/d) in both arches. Intraoral scans were performed directly (T0), 1 month (n= 88), 3 months (T2) (n= 78), and 6 months (T3) (n= 66) after retainer bonding. Nine reference points were marked on each tooth in every patient. Subsequent scans were superimposed, and point displacement was calculated. Statistical analysis was performed using the R statistical software (version 4.2.2; R Core Team, Vienna, Austria). Sample size calculation determined at least 55 patients were needed. The total dropout between T0 and T3 was 34 patients (did not show up for appointment). The median absolute displacement value of a single point between T0 and T3 was 0.015 mm. The most stable teeth were mandibular central incisors, whereas the least stable were mandibular molars. Most tooth displacements occurred between T0 and T2, then slowed down significantly. Double orthodontic retention prevents major tooth displacements in most patients during the first 6 months of retention; however, larger, unpredictable single-tooth displacement may occur in individual patients.

Effects of delayed appointments in fixed orthodontic patients due to lockdown during the COVID-19 pandemic

ObjectivesTo determine the frequency of orthodontic emergencies and their impact on the treatment progress caused by delayed appointments due to the lockdown during the COVID-19 pandemic. Materials and methodsTwo hundred thirty-eight patients undergoing fixed orthodontic treatment participated in this cross-sectional study. A pre-structured questionnaire was divided into six parts (Part A-C comprised of orthodontic emergencies and Part D-F comprised of various adverse effects and impacts on treatment progress). Two specialist orthodontists performed clinical examinations to complete the questionnaire. The final data were expressed as frequency and percentage. ResultsMaximum number of patients reported four months after lockdown. Nearly half of the patients reported debonding of at least one of the brackets. Loosening of molar bands and debonding of second molar tubes were observed in 12.6% and 18.9% of patients, respectively. Ligation method failures were reported in 41.2% of the patients. Patients fitted with transpalatal arch/lingual arch skeletal anchorage showed a failure rate of 26.1% and 10%, respectively. Almost 29% of the patient complained of discomfort due to distal wire impingement. Undesired tooth movements were seen in almost 25% of patients. Alignment, space closure, and settling of occlusion were affected in 47.6%, 17.4%, and 35.7% of patients, respectively. ConclusionsThis study helps to determine various types of adverse effects that can occur due to delayed appointments. The study's outcomes suggest that clinicians should be prepared to deal with future pandemics or other causes that might lead to delayed appointments.

Essential Attributes of Clear Aligner Therapy in terms of Appliance Configuration, Hygiene, and Pain Levels during the Pandemic: A Brief Review.

Fixed orthodontic treatment has been compromised at many levels during the pandemic period, as clinics underwent a prolonged lockdown and patients could not be treated regularly. With the end of the pandemic nowhere in sight, may be it is time to put newer tools, such as clear aligner therapy, for better use. Fixed orthodontic appliances by nature are not always self-limiting, which, if left unmonitored over a long period may cause undesirable side effects, pain, and discomfort. The undesired tooth movements that may occur with arch wire-guided mechanics in addition to problems with cut wires or removed brackets may be minimized with the use of aligners. While the benefits of using aligners are for all to see, they do require extensive planning and careful evaluation of the progress. This article reviews the advantages of using aligners during the pandemic period and how it can be beneficial in helping orthodontists resume their practice.

Deep overbite correction: Biomechanics and clinical implications

The goal of this paper is to describe and discuss the clinical use of intrusion mechanics during orthodontic therapy. The biomechanics of the classic segmented intrusion arch is explored along with modification of the appliance design to intrude and retract anterior teeth simultaneously. The advantages and limitations of intrusion mechanics are presented and the side effects analyzed to avoid undesired tooth movement and optimize clinical outcomes. The implications for the esthetic of the smile and the retention of intrusion are also discussed.

Effect of cortical bone thickness and density on pullout strength of mini-implants: An experimental study

Anchorage, which is defined as resistance against undesired tooth movements, is one of the most important factors in success of orthodontic treatment. In recent years, mini-implants have been used instead of uncomfortable headgears and Nance appliances. The pullout test is the most common method for measuring the anchorage capacity of mini-implants. The aim of this study was to investigate the effects of cortical bone thickness and cortical layer bone density on pullout strength of mini-implants. Mini-implants were placed in polyurethane foam blocks representing 3 different cortical thicknesses (1mm, 2mm, and 3mm) and 3 different cortical bone densities (grade 40, grade 45, and grade 50). Pullout tests were performed with 5mm/min loading rate. Load vs displacement values were recorded during the tests. Comparing cortical thicknesses on the same bone densities, statistically significant differences were found between 1mm, 2mm, and 3mm thicknesses. Likewise, comparing bone densities on the same cortical thicknesses, statistically significant differences were found among all groups. Spearman rank tests showed that both cortical thickness and cortical bone density are correlated with pullout strength (rs, 0.548; P<0.001 and rs, 0.691; P<0.001, respectively). Although both factors are positively correlated with pullout strength, the effect of cortical bone density was the dominant factor affecting primary stability.

Effects of calcitonin on orthodontic tooth movement and associated root resorption in rats

Objectives: Our main aim was to evaluate the effects of calcitonin (CT) on orthodontic tooth movement (OTM) and orthodontic root resorption in a rat model.Material and methods: Eighty male Wistar rats were randomly divided into five groups. Rats in the negative control group were not given any appliances or injections. All the remaining rats were used to establish a model of OTM. The positive control group were then injected with normal saline, while rats in the three experimental groups were injected with 0.2 IU, 1 IU or 5 IU/kg/day CT. Nickel-titanium closed-coil springs were used to deliver an initial 50 g mesial force to the left maxillary first molar for 14 days in rats in the positive control group and the experimental groups. Each group was randomly subdivided into two groups, one for analysis of tooth movement, tissue changes and tartrate-resistant acid phosphatase (TRAP)-positive cells in alveolar bone, the other to examine root resorption by scanning electron microscopy.Results: The OTM distance, the number of force-induced osteoclasts and root resorption areas were significantly decreased in CT-injected rats in a dose-dependent manner.Conclusions: Administration of CT reduces the root resorption area and may therefore be effective as a novel adjunctive orthodontic approach to diminish undesired tooth movement via enhancing anchorage or preventing relapse after OTM.

Post-treatment changes in permanent retention.

While permanent retention is today the method of choice to stabilize orthodontic treatment outcomes, recent studies have increasingly reported posttreatment changes in tooth position during permanent retention. We conducted this study to analyze changes in the anterior mandible, whether the changes follow an underlying movement pattern, and, aiming for a preventive strategy, whether any risk factors could be identified comparing findings with the pretreatment situations. We included 30 patients who had worn fixed Twistflex retainers (UK 3-3) extending from canine to canine in the mandible. Casts reflecting the intraoral situations before orthodontic treatment (T0), directly after completion of active therapy (T1), and 6months later (T2) were scanned and superimposed using Imageware Surfacer software. Posttreatment changes (T2-T1) of tooth position within the retainer block were analyzed on 3D virtual models and were compared to pretreatment (T0) and treatment-related (T1-T0) findings to identify potential risk factors. Almost all analyzed patients revealed three-dimensional changes in tooth position within the retainer block. Comparing these movements, we repeatedly found rotated retainer blocks in labio-oral direction, while the center of rotation was located at the first incisors. This pattern was associated with intercanine expansion and excessive overjet correction during orthodontic treatment. The canines underwent the most pronounced (rotational and translational) movements. In general permanent lingual retainers are safe but in special clinical cases retainers can induce undesired tooth movement. Risk factors seem to be intercanine expansion and excessive overjet correction during orthodontic treatment. In specific cases an additional retention device might be needed.

CBCT analysis of skeletal, dental and nasal changes after transpalatal distraction

Background: Transverse maxillary discrepancy is present 10–30% of patients eligible for combined orthodontic-surgical treatment. Surgical assisted rapid palatal expansion (SARPE) has proven to be a reliable treatment for the correction of a substantial transverse maxillary deficiency. Bone-borne expanders were introduced to provide more skeletal expansion, less undesired tooth movements and prevent relapse during consolidation.

Recombinant osteoprotegerin effects during orthodontic movement in a rat model.

Anchorage is one of the most challenging sides in orthodontics. The use of biological modulators that inhibit osteoclasts could be a solution to address these problems and provide new adjunctive approaches. The aim of this study was to assess the effectiveness of recombinant osteoprotegerin fusion protein (OPG-Fc) in orthodontic anchorage. Two groups of male Sprague-Dawley rats were utilized. The animals in the experimental group received twice-weekly injections with high dose of OPG-Fc (5.0mg/kg) in mesial and distal mucosa of the first molars, and those in the control group received no drugs. Right first maxillary molars were mesialized using a calibrated nickel-titanium spring connected to an anterior mini-screw. Tooth movement was measured by two blinded observers using scanned and magnified stone casts. Receptor activator of nuclear factor κB (RANK), run-related transcription factor 2 (Runx2), type I collagen, vimentin, matrix metalloproteinases 2 and 9, S100 protein and the putative mechanoproteins acid-sensing ion channel (ASIC2) and transient receptor potential vainilloid 4 (TRPV4) were evaluated using immunohistochemistry. OPG-Fc group showed an important decreased in mesial molar movement with only 52%, 31%, and 22% of the total mesial molar movement compared with control group at Days 7, 14, and 21, respectively (P < 0.001). RANK ligand and Runx2 positive cells were severely reduced after OPG-Fc treatment. Periodontal ligament architecture, cell arrangement, and immunohistochemical patter for vimentin, type I collagen and the mechanoproteins TRPV4 and ASIC2 were altered by tooth movement and all these parameters altered by the applied treatment. OPG-Fc effectively inhibits osteoclastogenesis resulting in improved bone quantity and orthodontic anchorage. Based on present results, OPG-Fc could have clinical utility in preventing undesired tooth movements.

Temporary skeletal anchorage devices: The case for miniscrews

5 According to Newton's Third Law, for every action, there is an equal and opposite reaction. Orthodontists must acknowledge this law every time they try to move teeth. Simply stated, every desired tooth movement has the potential to simultaneously create an undesired tooth movement. Orthodontic anchorage is defined as the resistance to such undesired tooth movement and can be achieved by more or less predictable methods. For space closure, 3 anchorage situations are traditionally defined by the ratio of incisor retraction to molar protraction. Maximum anchorage describes space closure mostly by incisor retraction and, to a lesser degree, by molar protraction (ratio of 2:1). Moderate anchorage comes with equal parts of incisor retraction and molar protraction (ratio of 1:1), whereas minimal anchorage allows spaces to close mostly by molar protraction and less by incisor retraction (ratio of 1:2). Traditionally, this type of anchorage control relies heavily on other appliances that add to the anchorage segment, such as compliance-dependent headgear or the noncompliance-dependent Nance appliance or, for instance, on elastic wear, which again depends on compliance. Although headgear incorporates skeletal structures into the anchorage segment (eg, high-pull headgear uses the occipital bone), elastics incorporate only other teeth into the anchorage segment, and this carries the potential for further side effects in the opposing dental arch. The philosophy behind skeletal anchorage is that if the reactive forces can be absorbed by skeletal structures, tooth movement can be limited to the desired therapeutic movements, and the undesirable reactive side effects can be prevented entirely. Such a situation can nowadays be created by temporarily implanting small devices into the patient's jawbone and using

Administration of bisphosphonate (ibandronate) impedes molar tooth movement in rabbits: A radiographic assessment.

Introduction:Bisphosphonate (Bp)-ibandronate is a pharmacological agent, exhibits antiosteoclastic or antiresorptive activity and used to treat osteolytic or osteopenic disorders. BP-ibandronate may also interfere during orthodontic tooth movement. The aim of this study was to examine the influence of locally administered Bp-ibandronate on experimental tooth movement in rabbits.Materials and Methods:Twenty rabbits were divided into two groups- “10” served as Group-1 (control) and other “10” as Group-2 (experimental). Both groups received nickel-titanium closed coil springs with 100 g force between mandibular molar and incisors. Group-1 animals received 1 ml normal saline and Group-2 animals received ibandronate solution (0.3 mg/kg body weight) locally, mesial to the mandibular molar on the 1st, 7th, and 14th day of the experiment. A total of “40” lateral cephalograms were taken from both groups on the 1st and 21st day using a digital X-ray unit (Siemens X-ray systems, 300 mA Pleomophos analog, 2008, Germany). Individually, each animal's radiograph was traced manually and superimposed. The molar tooth movement was measured with the help of a standard metric scale.Results:The Student's t-test has been done to compare the mean values of Group-1 (4.650 ± 0.363) and Group-2 (2.030 ± 0.291) and the difference was statistically significant (P < 0.001).Conclusion:The retarded molar tooth movement was noticed in local drug administered rabbits, which could be beneficial in orthodontics to control the undesired tooth movement.

Orthopedic expansion with orthodontic mini-implants: Case report

The goal of any orthodontic treatment is to achieve the desired movement of the teeth with minimal side effects. Mini-implants have biomechanical advantages that promote a more effective and efficient treatment. The use of orthodontic mini-implants for orthopedic maxillary expansion can considerably reduce undesired tooth movement. A clinical case report of a 13-year-old female who was diagnosed with a collapsed maxilla and treated with an acrylic device with an expansion screw anchored to two mini-implants placed in the palate and in the first molar for the expansion of the maxilla. The aim of this clinical case study was to analyze the separation of the maxillary suture by using orthodontic mini-implants, evaluate the transversal changes at the skeletal and dental level and the secondary effects induced in the teeth used as anchorage. Skeletal changes achieved in the patient treated with mini-implants were: maxillary width increased 3mm; regarding the dental changes, an increase in the intercanine distance of 3mm and an 8mm increase in the interpremolar and intermolar distance were observed. The secondary effect caused to anchorage teeth was buccal tipping of the first molars; in average, the right molar 1° and the left molar 4°. Orthodontic mini-implants are a reliable source for orthopedic anchorage since they provide acceptable skeletal changes with minimal side effects in teeth used as anchorage.

Expansión ortopédica del maxilar con miniimplantes ortodóncicos: Reporte de un caso

The goal of any orthodontic treatment is to achieve the desired movement of the teeth with minimal side effects. Mini-implants have biomechanical advantages that promote a more effective and efficient treatment. The use of orthodontic mini-implants for orthopedic maxillary expansion can considerably reduce undesired tooth movement. A clinical case report of a 13-year-old female who was diagnosed with a collapsed maxilla and treated with an acrylic device with an expansion screw anchored to two mini-implants, placed in the palate and in the first molar for the expansion of the maxilla. The aim of this clinical case study was to analyze the separation of the maxillary suture by using orthodontic mini-implants, evaluate the transversal changes at the skeletal and dental level and the secondary effects induced in the teeth used as anchorage. Skeletal changes achieved in the patient treated with mini-implants were: maxillary width increased 3mm; regarding the dental changes, an increase in the intercanine distance of 3mm and an 8mm increase in the interpremolar and intermolar distance were observed. The secondary effect caused to anchorage teeth was buccal tipping of the first molars; in average, the right molar 1° and the left molar 4°. Orthodontic mini-implants are a reliable source for orthopedic anchorage since they provide acceptable skeletal changes with minimal side effects in teeth used as anchorage.

Inhibition of tooth movement by osteoprotegerin vs. pamidronate under conditions of constant orthodontic force

The undesired movement of anchor teeth, and relapse of previously moved teeth, are major clinical problems in orthodontics. Dental implants are increasingly used to preserve anchorage, but these are costly and require invasive surgical procedures. An alternative strategy for maintaining anchorage may be the use of biological inhibitors of osteoclastic bone resorption. In the present study, we investigated the relative efficacy of pamidronate vs. osteoprotegerin (OPG) in inhibiting bone resorption and tooth movement, using a new orthodontic model in mice in which maxillary molars are moved for prolonged periods by near-constant, clinically relevant forces. Osteoclast influx to compression sites was initiated on day 3, was maximal on day 4, and persisted until at least day 12 after force application. Tooth movement paralleled osteoclast numbers. Minimal osteoclast apoptosis was observed, suggesting that recruitment, rather than programmed cell death, is a critical regulatory mechanism under conditions of constant force. Osteoclasts were reduced at compression sites by both OPG (95%) and pamidronate (70%); tooth movement was more dramatically inhibited by OPG (77% vs. 34%). Our findings indicate that constant orthodontic force regulates the recruitment, activation, and viability of osteoclasts, and that OPG could have clinical utility in preventing undesired tooth movement.