The Angle Orthodontist[JOURNAL]
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200 papers
Effects of refinement procedures on enamel surface integrity in clear aligner therapy: a 3D micro-CT study.
Turkoglu-Boynuyogun H, Ocak I, Atik E
Angle Orthod · 2026 Apr · PMID 41916601 · Publisher ↗
OBJECTIVES: To evaluate topographic changes on the enamel surface after different debonding methods of clear aligner attachments using three-dimensional (3D) micro-computed tomography (Micro-CT). MATERIALS AND METHODS: V...
OBJECTIVES: To evaluate topographic changes on the enamel surface after different debonding methods of clear aligner attachments using three-dimensional (3D) micro-computed tomography (Micro-CT). MATERIALS AND METHODS: Vertical rectangular attachments were attached to 20 premolars and divided into two subgroups (N = 10) using different debonding methods. Micro-CT scans were performed showing the enamel surfaces of each group before bonding (T0), after the first debonding procedure (T1), and after the second debonding with polishing (T2). In Group 1, excess attachment composite was removed with a 12-blade carbide bur, followed by a 24-blade carbide bur, and then the tooth surface was polished with a Renew stone. In Group 2, the attachment composite was removed with a Komet-H23VIP bur and polished with a compatible polishing kit. Morphological changes in the enamel surface were compared within groups using repeated-measures analysis of variance and between groups using independent samples t-tests. Values of P < .05 were considered statistically significant. RESULTS: Significant decreases in enamel demineralization volume (P < .001), area (Group 1: P < .001; Group 2: P = .020), and mineral density (P < .001) were observed in both groups. Intragroup comparison revealed no significant difference in demineralization volume or area changes, but enamel mineral density was better preserved in Group 2 (T1-T2, P = .006; T0-T2, P = .008). CONCLUSIONS: The cumulative effect of repeated attachment debonding is significant, with tissue loss becoming more pronounced after the second application. The need for refinement should be carefully evaluated.
Effects of lithium on orthodontically induced root resorption and tooth movement in an osteoporotic rat model.
Ohama M, Hotokezaka Y, Hotokezaka H … +7 more , Funaki-Dohi M, Iuchi Y, Yamamoto H, Nakamura T, Nashiro-Oyakawa Y, Nishioka-Sakamoto K, Yoshida N
Angle Orthod · 2026 Mar · PMID 41881360 · Publisher ↗
OBJECTIVES: To assess the effects of lithium on orthodontically induced root resorption (OIRR) and orthodontic tooth movement (OTM) and elucidate the underlying mechanisms in an osteoporotic rat model. MATERIALS AND METH...
OBJECTIVES: To assess the effects of lithium on orthodontically induced root resorption (OIRR) and orthodontic tooth movement (OTM) and elucidate the underlying mechanisms in an osteoporotic rat model. MATERIALS AND METHODS: Thirty 10-week-old female Wistar rats were randomly assigned to ovariectomized (OVX) or sham-operated (Sham) groups. Four weeks post-surgery, each group was further divided to receive either lithium (Li: 0.64 mM/kg) or saline via daily intraperitoneal injection. Orthodontic force was applied for 14 days using a closed-coil spring to move the maxillary first molar mesially. OTM was analyzed using micro-computed tomography on day 14. Histological analysis evaluated OIRR, apoptotic cells, osteoclasts, and odontoclasts. Immunohistochemical staining was used to assess the expression of receptor-activated nuclear factor-kappa B ligand and osteoprotegerin. RESULTS: OIRR was significantly higher in the OVX group than Sham groups. Lithium markedly suppressed OIRR in OVX rats to levels comparable to the Sham + Li group. Lithium significantly reduced the number of apoptotic cells on day 3, decreased the number of odontoclasts, and increased osteoprotegerin expression by day 14. It also prevented excessive tooth tipping without affecting the overall distance of tooth movement, promoting a shift from tipping to bodily movement in the OVX group. CONCLUSIONS: In an osteoporotic rat model, lithium effectively suppressed OIRR and promoted bodily tooth movement without reducing OTM distance, suggesting the therapeutic potential of lithium in patients with osteoporosis.
Efficacy of leukocyte-platelet-rich fibrin (L-PRF) and injectable platelet-rich fibrin (i-PRF) on the rate of canine retraction: a split mouth, randomized controlled trial.
Kamrani A, Khera AK, Raghav P … +3 more , Reddy CM, Srivastava A, Sanyal D
Angle Orthod · 2026 Mar · PMID 41881359 · Publisher ↗
OBJECTIVES: To evaluate and compare the effects of leukocyte-platelet-rich fibrin (L-PRF), injectable platelet-rich fibrin (i-PRF; submucosal), and i-PRF (intraligamental) on the rate of maxillary canine retraction. MATE...
OBJECTIVES: To evaluate and compare the effects of leukocyte-platelet-rich fibrin (L-PRF), injectable platelet-rich fibrin (i-PRF; submucosal), and i-PRF (intraligamental) on the rate of maxillary canine retraction. MATERIALS AND METHODS: A randomized controlled trial was conducted on 33 participants requiring bilateral maxillary first premolar extraction. Participants were divided into three groups: L-PRF in extraction sockets, submucosal i-PRF injections, and intraligamental i-PRF injections. Each group followed a split-mouth design with the contralateral side serving as control. Canine retraction was done using NiTi closed-coil springs delivering 150 g force. Tooth movement was assessed monthly for 5 months using digital model measurements. RESULTS: L-PRF (Group I) achieved significantly greater canine retraction than its control in the first 2 months (4.65 mm vs 3.77 mm). Submucosal i-PRF (Group II) also outperformed its control (4.57 mm vs 3.80 mm) but with declining effect. Intraligamental i-PRF (Group III) failed to show any significant advantage over its control (4.14 mm vs 3.74 mm). Anchorage loss and root resorption were comparable between intervention and control sites in all groups. CONCLUSIONS: L-PRF and submucosal i-PRF significantly accelerated canine retraction in the early phase, with greater total movement at 5 months. Intraligamental i-PRF showed no significant effect. All PRF methods were safe, with no increase in anchorage loss or root resorption.
Association between cranial structure and choice of bolus hardness in an orthodontic sample.
Tortarolo A, Lugarà B, di Benedetto L … +4 more , Leiva Ramirez E, Tonni I, Caprioglio A, Piancino MG
Angle Orthod · 2026 Mar · PMID 41881351 · Publisher ↗
OBJECTIVES: To assess whether craniofacial morphology and vertical growth patterns are associated with a preference for hard or soft alimentary boluses in a sample of orthodontic patients. MATERIALS AND METHODS: This cro...
OBJECTIVES: To assess whether craniofacial morphology and vertical growth patterns are associated with a preference for hard or soft alimentary boluses in a sample of orthodontic patients. MATERIALS AND METHODS: This cross-sectional study included 121 orthodontic patients (69 females, 52 males; mean age = 12.3 ± 3.3 years). Before-treatment, lateral skull x-rays were collected and lateral cephalometric analysis performed, considering variables SpP^GoGn, SN^GoGn, SpP^CoOr, and AN^B. Before undergoing chewing pattern analysis, each patient was asked to chew a standardized soft bolus (chewing gum) and subsequently a standardized hard bolus (wine gum) in a flavor of their choice. Subsequently, each patient was asked to express a preference for one of the two boluses, and the answer was recorded. To assess the association between bolus hardness preference and cephalometric variables, multiple linear regression analyses were performed, controlling for sex and age. RESULTS: Soft bolus was preferred by 64% of subjects (n = 77) and hard bolus by 36% (n = 44). Increased SpP^GoGn angle was significantly associated with soft-bolus preference (P <.05) as well as being female but was independent of age. SN^GoGn increased with age (P <.05) but did not correlate with bolus preference or sex. No significant associations were observed for SpP^CoOr and AN^B. CONCLUSIONS: Soft bolus preference was significantly associated with increased intermaxillary divergence but not with cranial divergence, mandibular rotation, or sagittal skeletal relationship. These findings suggest that patients with intermaxillary hyperdivergent patterns may self-select softer boluses, due to a compensatory functional-structural feedback loop.
Facial profile and nasolabial angle-upper incisor relationship: effects of miniscrew-anchored maxillary protraction therapy in adolescents.
Vedovello SAS, Tozzi CF, Nunes JT … +4 more , Manhães FR, Valdrighi HC, Innocent GG, de Menezes CC
Angle Orthod · 2026 Mar · PMID 41862159 · Publisher ↗
OBJECTIVES: To evaluate the effects of miniscrew-anchored maxillary protraction on the soft tissue profile, focusing on facial convexity and the correlation between upper incisor position and the nasolabial angle. MATERI...
OBJECTIVES: To evaluate the effects of miniscrew-anchored maxillary protraction on the soft tissue profile, focusing on facial convexity and the correlation between upper incisor position and the nasolabial angle. MATERIALS AND METHODS: Twenty growing patients with skeletal Class III malocclusion and maxillary deficiency were treated with a Hyrax hybrid expander and a mandibular anchorage bar supported by two miniscrews. Class III elastics were worn from the maxillary molars to the bar, fitting the miniscrews between the incisors and canines, and a facemask was used only at night. Soft tissue effects were assessed using lateral radiographs and standardized profile photographs before (T1) and after (T2) treatment. Measurements were obtained with Dolphin software. The Wilcoxon paired test compared changes, and Pearson correlation assessed the association between incisor position and nasolabial angle. RESULTS: The final sample included 17 subjects (mean age: 12.3 years, SD = 1.2). Lip position and H.NB angle increased significantly (P < .05), whereas the nasolabial angle and facial convexity decreased (P < .05). A negative correlation was observed between the nasolabial angle and upper incisor position (P < .05). CONCLUSIONS: Miniscrew-anchored maxillary protraction improved the facial profile by reducing concavity. Upper incisor advancement was associated with a decrease in the nasolabial angle, confirming the influence of dental movement on soft tissue balance.
Assessment of three different techniques in correcting deep overbite: a prospective clinical study.
Khaleel R, Al-Nimri K
Angle Orthod · 2026 Mar · PMID 41856372 · Publisher ↗
OBJECTIVES: To study the effect of using reverse curve of Spee (RCOS) archwires or posterior vertical elastics with anterior bite turbos (ABTs) during deep overbite management. MATERIALS AND METHODS: Eighty-one patients...
OBJECTIVES: To study the effect of using reverse curve of Spee (RCOS) archwires or posterior vertical elastics with anterior bite turbos (ABTs) during deep overbite management. MATERIALS AND METHODS: Eighty-one patients with excessive overbite treated with ABTs were divided into three equal groups: Group I (mean age = 15.82 years) received 0.016 × 0.022 nickel titanium RCOS archwires, Group II (mean age = 16.00 years) received posterior vertical elastics, and Group III (mean age = 17.35 years) received bite turbos alone. Standardized lateral cephalograms were taken at baseline (T1) and after overbite correction (T2). RESULTS: A total of 80 patients completed the study. All groups showed similar reductions in overbite. Group II required the shortest treatment duration (44.4 days), followed by Group I (55.7 days) and Group III (94.2 days, P < .001). Group I experienced lower incisor proclination (7.5°), true incisor intrusion (1 mm), and distal molar tipping. Group II exhibited posterior tooth extrusion (up to 1.1 mm and 0.42 mm in the lower and upper arches, respectively) with minimal incisor change. Group III overbite reduced mainly by passive eruption of lower posterior teeth. Vertical skeletal measurements increased significantly in all groups, with the smallest increase in Group III. CONCLUSIONS: All three approaches corrected deep overbite successfully. Posterior elastics with bite turbos were the most efficient. RCOS wires with bite turbos produced greater proclination and intrusion of the lower incisors. Bite turbos alone achieved slower correction, primarily through eruption of lower posterior teeth.
Mechanobehavior and mandibular growth in children with Class II skeletal malocclusions.
Iwasaki LR, Gallo LM, Choi D … +3 more , Liu H, Liu Y, Nickel JC
Angle Orthod · 2026 Mar · PMID 41856368 · Publisher ↗
OBJECTIVES: To evaluate if mandibular growth was influenced by the mechanobehavior (magnitude and frequency) of temporomandibular joint (TMJ) loading, the hypotheses tested were: Time 1 (T1) mechanobehavior and age corre...
OBJECTIVES: To evaluate if mandibular growth was influenced by the mechanobehavior (magnitude and frequency) of temporomandibular joint (TMJ) loading, the hypotheses tested were: Time 1 (T1) mechanobehavior and age correlated with changes (Δ) in lengths of (1) ramus (CoAS-Go) and (2) mandible (CoP-Gn) at Time 2 (T2) after Herbst appliance therapy (HAT). MATERIALS AND METHODS: Subjects had Class II skeletal malocclusions for which HAT was planned and gave informed consent to participate. Anatomy, including CoAS-Go and CoP-Gn, were derived from cone-beam computed tomography at both timepoints. T1 loading magnitudes were measured as TMJ energy densities (ED, mJ/mm3) using dynamic stereometry, loading frequencies were measured as jaw muscle duty factors (DFs, %) from at-home electromyography (EMG) recordings made by subjects, and mechanobehavior scores (MBS; MBS = ED2xDF, (mJmm3)2 %) were calculated for each TMJ. Generalized additive models tested for effects of T1 MBS and age on ΔCoAS-Go and ΔCoP-Gn. RESULTS: Fifteen subjects (eight females, seven males) with T1 age of 12.7 ± 1.3 years completed protocols and HAT of 12.0 ± 1.1 months. Subjects produced 37 daytime and 42 night-time electromyographic recordings of 6.3 ± 1.1 and 8.9 ± 1.3 hours, respectively. Normalized changes in ramal and mandibular lengths vs T1 overall MBS and age showed significant nonlinear relationships (P = .003 and < .0001 with adjusted R2= 0.54 and 0.74, respectively), where relatively larger MBS and younger age showed larger changes in ramal and mandibular lengths after HAT. CONCLUSIONS: Initial mechanobehavior and age were significantly correlated with changes in lengths of the ramus and the mandible after Herbst appliance therapy.
Comparison of dentoskeletal effects of elastic chain vs metallic ligature for miniscrew-anchored Herbst appliance: a retrospective study.
Liao J, Zheng W, Xu Y … +2 more , Zhou Z, Li Z
Angle Orthod · 2026 Mar · PMID 41856364 · Publisher ↗
OBJECTIVES: To evaluate the dentoskeletal effects of a miniscrew-anchored Herbst appliance using two different connection methods, elastic chains and metallic ligatures, compared with a conventional Herbst appliance, in...
OBJECTIVES: To evaluate the dentoskeletal effects of a miniscrew-anchored Herbst appliance using two different connection methods, elastic chains and metallic ligatures, compared with a conventional Herbst appliance, in adolescent patients with skeletal Class II malocclusion. MATERIALS AND METHODS: A retrospective study was conducted involving 48 patients aged 10-15 years, divided into three groups: Group I (conventional) received conventional Herbst treatment; Group II (ligated) received miniscrew-anchored Herbst with metallic ligatures; and Group III (elastic) received miniscrew-anchored Herbst with elastic chains. Miniscrews were placed in the mandibular external oblique ridge. Lateral cephalograms were analyzed using Dolphin Imaging software to assess skeletal and dental changes before and after treatment. RESULTS: All groups showed significant improvements in overjet, molar relationship, and sagittal discrepancy. However, the elastic group exhibited the greatest control over mandibular incisor proclination, with a mean reduction of 3.51° in li/GoMe, compared with increases of 8.89° in the conventional and 2.04° in the ligated groups. SNB increased and ANB decreased in all groups, with the most pronounced skeletal changes observed in the conventional group. No miniscrew failures occurred. CONCLUSIONS: Miniscrew-anchored Herbst appliances, particularly those using elastic chains, effectively reduce undesirable mandibular incisor proclination while maintaining therapeutic efficacy. The external oblique ridge proved to be a stable site for miniscrew placement.
Effects of simulated arch constriction on upper airway function during sleep.
Kim DI, Lagravère MO, Almeida F … +1 more , Pliska BT
Angle Orthod · 2026 Mar · PMID 41850550 · Publisher ↗
OBJECTIVES: To characterize functional changes of the airway while wearing an appliance simulating severe arch constriction using level 3 polysomnography. MATERIALS AND METHODS: For this pilot, single-blinded prospective...
OBJECTIVES: To characterize functional changes of the airway while wearing an appliance simulating severe arch constriction using level 3 polysomnography. MATERIALS AND METHODS: For this pilot, single-blinded prospective randomized cross-over trial, 34 participants were recruited from the student/staff population of a dental school. Epworth Sleepiness Scale, STOPBANG questionnaire, lateral cephalograms, and digital dental casts were gathered from all patients. Arch constriction was simulated by adding 5 mm thickness to lingual aspects of the dentition using vacuum-formed retainers (VFRs). Each participant completed three at-home sleep studies with a level 3 sleep monitor: the initial baseline test, and after random allocation of 6 days wearing either the control appliance (regular-VFR), or the simulated arch constriction (SAC) appliance, and following crossover of appliances. Oxygen Desaturation Indices (ODIs) and Respiratory Event Index (REI) were compared. RESULTS: Use of the SAC appliance did not affect airway function: No significant difference (P > .05) was found in REI or ODI among the three groups. Five participants had REI values 5.0 or greater on at least one sleep study; however, this was unrelated to appliance use. CONCLUSION: Simulated extreme dental arch constriction did not result in changes to REI. Constriction of the dental arches does not negatively affect airway function during sleep.
Predictability of clear aligners in achieving planned dental arch expansion during mixed dentition: a systematic review and meta-analysis.
Serafin M, Boccalari E, Caprioglio A
Angle Orthod · 2026 Mar · PMID 41833315 · Full text
OBJECTIVES: To assess the predictability of Invisalign First in achieving planned dental arch expansion in mixed dentition. MATERIALS AND METHODS: Following PRISMA guidelines and a PROSPERO-registered protocol (CRD420251...
OBJECTIVES: To assess the predictability of Invisalign First in achieving planned dental arch expansion in mixed dentition. MATERIALS AND METHODS: Following PRISMA guidelines and a PROSPERO-registered protocol (CRD420251083929), electronic databases were searched up to July 2025. Eligible studies included data evaluating Invisalign First for dental arch expansion in mixed dentition. Predictability, defined as ratio of achieved to planned expansion, was the primary outcome. Meta-analyses of proportions were performed separately for maxillary and mandibular arches using binomial modeling on logit scale. Correlation analyses and univariate linear regression were conducted to assess the relationship between planned expansion and achieved predictability, globally and by arch and tooth group. Risk of bias was evaluated with ROBINS-I and publication bias by funnel plot and Egger's and Begg's tests. Certainty of evidence was assessed with GRADE. RESULTS: Nine studies were included in the systematic review and eight in the meta-analysis. Pooled predictability of expansion in the maxilla was 65%, with the lowest at permanent first molars (58%) and the highest at deciduous canines (70%). Expansion in the mandible showed higher predictability (71%), peaking at deciduous canines (75%). Correlation and regression analyses found no significant association between amount of planned expansion and achieved predictability in any subgroup. No evidence of publication bias was found, and findings remained robust on sensitivity analysis. GRADE certainty was low (maxilla) and moderate (mandible). CONCLUSIONS: Invisalign First demonstrates modest to moderate predictability for dental arch expansion in mixed dentition, particularly in the mandibular arch and anterior teeth, though limitations persist in the posterior maxilla.
Impact of three types of presurgical infant orthopedics on nasolabial appearance in unilateral cleft lip and palate: a 4-year follow-up study.
Batra P, Kubavat A, Kuijpers-Jagtman AM … +2 more , Gribel BF, Ahuja D
Angle Orthod · 2026 Mar · PMID 41833311 · Publisher ↗
OBJECTIVES: To evaluate the impact of presurgical infant orthopedics (PSIO) on nasolabial appearance among three PSIO methods (modified Grayson's technique, DynaCleft nasal elevator, OrthoAligner NAM with DynaCleft nasal...
OBJECTIVES: To evaluate the impact of presurgical infant orthopedics (PSIO) on nasolabial appearance among three PSIO methods (modified Grayson's technique, DynaCleft nasal elevator, OrthoAligner NAM with DynaCleft nasal elevator) and no-PSIO in children with unilateral cleft lip and palate (UCLP) at 4 years' follow-up. MATERIALS AND METHODS: This study took place in an academic and a peripheral center at which patients with UCLP were treated and followed. A total of 48 patients with UCLP were divided into four groups of 12 patients each. Group 1 underwent PSIO using modified Grayson's technique. Group 2 received PSIO incorporating DynaCleft nasal elevator. Group 3 treatment involved OrthoAligner NAM in combination with DynaCleft nasal elevator, whereas Group 4 did not receive any form of PSIO. Asher-McDade Aesthetic Index (AMAI) and Cleft Aesthetic Rating Scale (CARS) were used to assess nasolabial appearance 4 years post-lip surgery (mean age: 4.3 years ± 6 months) on standardized photographs of the nasolabial region. Kruskal-Wallis test was used to assess nasolabial appearance scores among treatment groups. RESULTS: Nasolabial appearance showed no significant differences between PSIO and no-PSIO groups across facial esthetic indices regarding nasal form (P = .819), deviation of the nose (P = .403), shape of the vermillion border (P = .801), nasal profile including upper lip (P = .726), nose (P = .973), and lips (P = .72). CONCLUSIONS: In patients with UCLP, there was no significant difference in nasolabial appearance 4 years after lip repair when comparing three different PSIO modalities to no-PSIO group.
How stable are SLA-printed orthodontic models: a 6-month in vitro evaluation.
Barreto LSDC, Malheiros MKS, Barreto BCT … +4 more , Marassi C, Marañón-Vásquez GA, Squeff LR, Araújo MTS
Angle Orthod · 2026 Mar · PMID 41833310 · Full text
OBJECTIVES: To evaluate dimensional stability of models fabricated using stereolithography (SLA) 3D printing. MATERIALS AND METHODS: Twelve resin models were printed from a STL file using an SLA 3D printer, according to...
OBJECTIVES: To evaluate dimensional stability of models fabricated using stereolithography (SLA) 3D printing. MATERIALS AND METHODS: Twelve resin models were printed from a STL file using an SLA 3D printer, according to manufacturer specifications. Dimensional stability was assessed through 4752 total measurements across upper and lower arches at eight timepoints: immediately after printing (T0), 3 hours (T1), 6 hours (T2), 12 hours (T3), 24 hours (T4), 7 days (T5), 30 days (T6), and 6 months (T7). Measurements were made in triplicate with a 6-inch digital caliper: intermolar distance (central grooves and mesiobuccal cusp tips), intercanine distance (cusp tips), and mesiodistal tooth size (maximum crown width of 28 teeth). Linear mixed models (restricted maximum likelihood) were used to assess the effects of time, arch, side, measurement/tooth type, and their interactions, with dental models as a random effect. Bonferroni post hoc tests identified pairwise differences, and model assumptions were verified. RESULTS: Significant effects of time were detected for transverse distances (P = .002) and mesiodistal tooth sizes (P < .001). These effects did not show significant interactions with arch, side, or type of measurement/tooth (P > .05). Both transverse widths and tooth sizes showed a statistically significant reduction starting from evaluation T5 (after 7 days of printing). CONCLUSIONS: Orthodontic models produced by SLA 3D printing maintain high dimensional accuracy in the short term, supporting their immediate use in clinical settings for aligner fabrication. However, delayed use or prolonged storage can lead to measurable distortions that may compromise appliance fit and treatment efficacy.
Effects of virtual reality relaxation on anxiety levels of adolescents and adults during orthodontic bonding: a randomized controlled trial.
Kelly K, Preusse E, Wong A … +4 more , Bhamidipalli S, Eckert G, Schrader S, Turkkahraman H
Angle Orthod · 2026 Mar · PMID 41833309 · Publisher ↗
OBJECTIVES: To assess the effectiveness of virtual reality relaxation (VRR) as an intervention for reducing anxiety in adolescents and adults during the orthodontic bonding procedure. MATERIALS AND METHODS: This prospect...
OBJECTIVES: To assess the effectiveness of virtual reality relaxation (VRR) as an intervention for reducing anxiety in adolescents and adults during the orthodontic bonding procedure. MATERIALS AND METHODS: This prospective clinical study included 53 patients undergoing fixed orthodontic treatment at the Indiana University School of Dentistry. Participants were randomly assigned to one of two groups: the experimental group using VRR during orthodontic direct bonding or the control group receiving no distraction. Physiological measures (blood pressure [BP], heart rate [HR], and oxygen saturation) and psychological assessments (5-item State-Trait Anxiety Inventory-Short Form, and the Visual Analog Scale for Anxiety [VAS-A]) were collected at baseline (T0) and 30 minutes into the bonding procedure after bonding of one arch (T1). Repeated measures of analysis of variance were used to compare groups and timepoints. RESULTS: At T0, no statistically significant differences were found between the control and VRR groups across any psychological or physiological measures (P > .05). Although both groups showed significant reductions for physiological and psychological measures from T0 to T1 (P < .01), the VRR group reported significantly lower VAS-A scores, HR, and diastolic BP at T1 than the control group (P < .05). CONCLUSIONS: VRR effectively reduced psychological and physiological anxiety during orthodontic bonding procedures, supporting VRR as a promising adjunctive tool in managing dental anxiety during orthodontic care.
Early apoptosis predicts orthodontically induced root resorption: inhibitory effects of lithium in a rat model.
Iuchi Y, Hotokezaka Y, Hotokezaka H … +7 more , Funaki-Dohi M, Nakamura T, Ohama M, Nashiro-Oyakawa Y, Nishioka-Sakamoto K, Morita Y, Yoshida N
Angle Orthod · 2026 Mar · PMID 41833306 · Full text
OBJECTIVES: Mechanical compression of the periodontal ligament (PDL) is a key trigger of orthodontically induced root resorption (OIRR). Although PDL compression during the early phase of orthodontic force application co...
OBJECTIVES: Mechanical compression of the periodontal ligament (PDL) is a key trigger of orthodontically induced root resorption (OIRR). Although PDL compression during the early phase of orthodontic force application correlates strongly with OIRR severity, associated cellular events remain insufficiently defined. This study aimed at elucidating mechanisms underlying the initiation of OIRR, focusing on PDL compression and associated cellular responses, and identifying cellular targets through which lithium exerts inhibitory effects. MATERIALS AND METHODS: Thirty-seven 10-week-old male Wistar rats were assigned to lithium-treated and saline groups. Daily intraperitoneal injections were administered, and a 25 cN mesial orthodontic force was applied to the maxillary first molar for 14 days. PDL thickness was evaluated using microcomputed tomography. Histological analyses quantified the OIRR area, apoptotic cell count, and odontoclast number. RESULTS: In both groups, early PDL compression ratios showed strong positive correlations with OIRR area and early apoptotic cell counts. Lithium significantly reduced OIRR but did not alter PDL compression compared with saline. At comparable PDL compression ratios, the lithium group exhibited consistently smaller OIRR areas and fewer early apoptotic cells. The early odontoclast numbers remained low and showed no intergroup differences. These findings suggest that the protective effect of lithium was primarily mediated by the suppression of early apoptosis, cellular response to PDL compression. CONCLUSIONS: Early PDL compression and apoptosis play pivotal roles in OIRR initiation and are potential predictive markers. Lithium attenuated OIRR by suppressing early apoptosis without altering PDL compression, highlighting early apoptosis as a promising therapeutic target for OIRR prevention.
Effect of skeletal miniscrew-assisted rapid palatal expansion on root resorption, buccal bone thickness and tooth inclination: a retrospective CBCT study.
Al-Qaqaa S, Al-Khateeb SN, Al Samhouri A
Angle Orthod · 2026 Mar · PMID 41813063 · Full text
OBJECTIVES: To evaluate the effect of miniscrew-assisted rapid palatal expansion (MARPE) on root resorption, buccal bone thickness, and tooth inclination. MATERIALS AND METHODS: This study included 30 patients with maxil...
OBJECTIVES: To evaluate the effect of miniscrew-assisted rapid palatal expansion (MARPE) on root resorption, buccal bone thickness, and tooth inclination. MATERIALS AND METHODS: This study included 30 patients with maxillary constriction who were treated with MARPE. The device was left in place for 6 months for retention. Cone-beam computed tomography (CBCT) images were taken before treatment and after 6 months. CBCT images were analyzed for root length, buccal bone thickness, and tooth inclination for premolars and first molar on both sides. A paired t-test was used to compare between pretreatment and posttreatment root lengths, buccal bone thickness, and buccal tooth inclination. RESULTS: No significant differences were found between pretreatment and posttreatment root lengths of all measured teeth (P value > .05). A significant difference was found in the buccal bone thickness at the right second premolar at the levels of 2 mm and 8 mm (P = .049 and P = .039, respectively) and at the level of 2 mm for the left second premolar (P = .009). Buccal bone thickness at the right and left mesiobuccal root of the first molar at 8 mm was significantly reduced after expansion (P = .001). The difference between pre-expansion and postexpansion in tooth inclination ranged between -1.87 and 0.27. Only the inclination of the left first molar was significantly increased after expansion. CONCLUSIONS: No root resorption was caused by the bone-borne MARPE. No change in buccal bone thickness and inclination of most of the posterior maxillary teeth was found.
Efficacy of planned overjet, overbite, arch depth and incisor labiolingual changes with the Invisalign Lite appliance: a retrospective analysis.
Meade MJ, Blundell H, Giulieri C … +1 more , Weir T
Angle Orthod · 2026 Mar · PMID 41771498 · Full text
OBJECTIVES: To compare planned and achieved outcomes for an initial series of Invisalign Lite (Align Technology, Santa Clara, Calif) aligners regarding overjet, overbite, arch depth, and incisor labiolingual inclination....
OBJECTIVES: To compare planned and achieved outcomes for an initial series of Invisalign Lite (Align Technology, Santa Clara, Calif) aligners regarding overjet, overbite, arch depth, and incisor labiolingual inclination. MATERIALS AND METHODS: Relevant data from adult patients satisfying inclusion criteria regarding overjet and overbite were obtained from the Align Technology treatment planning application. Metrology software was employed to calculate pretreatment, planned, and achieved arch depth and labiolingual measurements of maxillary and mandibular central incisors. Bland-Altman plots were used to demonstrate findings. RESULTS: Most (n = 95; 79.5%) of 122 patients satisfying selection criteria were female. For overjet, mean differences were + 0.183 mm (SD: 0.557). P values (both = 1.000) indicated that differences did not lie outside the clinically acceptable interval ± 0.5 mm. For overbite, with a mean difference of + 0.746 mm (SD: 0.857), Bland-Altman plot showed a potential proportional bias, with discrepancies increasing as initial overbite increased. Across all arch depth subgroups, differences remained within an acceptable range, and no differences (P > .05) were detected between planned and achieved outcomes. Achieved mandibular incisor labiolingual inclination outcomes closely matched those planned with a mean difference of -1.088° (SD = 2.78°), whereas corresponding outcomes in the maxilla (-2.905° [SD = 2.671°]) indicated a consistent tendency for achieved to be lower than planned. CONCLUSIONS: Although achieved overjet, arch depth and mandibular incisor labiolingual inclination measurements closely matched those planned, there were significant statistical and clinical differences between planned and achieved overbite and maxillary incisor labiolingual inclination measurements.
Clear aligner attachment accuracy and composite excess using flowable composite resins of varying viscosities.
Doğrugören R, Demir GB, Dalgalı P … +2 more , Topsakal KG, Duran GS
Angle Orthod · 2026 Mar · PMID 41771494 · Full text
OBJECTIVES: To evaluate the accuracy of clear aligner attachments and quantify excess composite volume when using flowable composite resins with different viscosities in an in vitro setting. The null hypothesis was that...
OBJECTIVES: To evaluate the accuracy of clear aligner attachments and quantify excess composite volume when using flowable composite resins with different viscosities in an in vitro setting. The null hypothesis was that viscosity would not significantly impact accuracy or excess. MATERIALS AND METHODS: A total of 120 samples was evaluated. Four attachment types: ellipsoid (EA), rectangular (RA), beveled (BA), and half-moon (HMA), were applied using three flowable composites: Estelite Universal Flow High (HF), Medium (MF), and Super-Low (SLF) viscosity (Tokuyama Dental, Japan). Attachments were bonded on three-dimensionally printed typodont models and digitally scanned. Digital scans were aligned with reference models using local best-fit analysis. Surface deviation was measured at five points, and overall deviation was represented by arithmetic mean and standard deviation (sigma) values. Excess composite area and volume were calculated. The data were nonnormally distributed, so nonparametric tests were used: Kruskal-Wallis for group comparisons and Mann-Whitney U for pairwise analyses (P < .05). RESULTS: Significant differences in attachment accuracy and excess composite were observed among viscosity groups. In EA and RA groups, HF composite showed significantly greater accuracy than MF and SLF (P = .016, P = .018). In BA, SLF exhibited lower accuracy than HF and MF (P = .005). Excess composite volume was significantly higher in EA and HMA with HF composite (P = .011 and P = .002, respectively). CONCLUSIONS: Composite viscosity and attachment shape influence accuracy and excess. High-viscosity resins improve precision but increase excess; low-viscosity resins reduce excess but may compromise accuracy. Both material and attachment design should guide clinical choices in clear aligner treatment.
Retraction and rotation of the mandibular arch with buccal shelf bone screws to resolve Class III skeletal malocclusion.
Lee HT, Lin JH, Chang CH … +1 more , Roberts WE
Angle Orthod · 2026 Feb · PMID 41759913 · Full text
OBJECTIVES: To elucidate the retraction effectiveness of extra-alveolar mandibular buccal shelf (MBS) bone screws anchorage relative to the presence of mandibular third molars and ANB angle in Class III patients. MATERIA...
OBJECTIVES: To elucidate the retraction effectiveness of extra-alveolar mandibular buccal shelf (MBS) bone screws anchorage relative to the presence of mandibular third molars and ANB angle in Class III patients. MATERIALS AND METHODS: This retrospective study included 45 patients (mean age = 22.2 ± 6.7 years) treated with bilateral MBS stainless steel bone screws (2 × 12 mm). Patients were subgrouped based on mandibular third molar status and ANB angle (≤-2° vs > -2°). Pretreatment and posttreatment cephalograms were superimposed and analyzed. Statistical tests included analysis of variance, paired and independent t-tests, and linear regression. RESULTS: Mean retraction of mandibular first molars and incisors was 1.86 ± 1.36 mm and 2.89 ± 1.64 mm, respectively, over an average of 9.0 months. Retraction ≥ 3 mm was significantly associated with treatment durations ≥ 12 months (P < .001). No significant differences in retraction outcomes were found among third molar subgroups. The severe malocclusion group (ANB ≤ -2°) showed greater molar retraction and overjet increase. A moderate positive correlation was found between molar crown retraction and retraction duration (R2 = 0.282, P < .001). CONCLUSIONS: MBS bone screws provide effective, minimally invasive anchorage for mandibular whole-arch retraction in Class III patients. Treatment outcomes are not hindered by third molars in adolescents, and longer retraction duration enhances distal movement.
Comparison of conventional and self-adhesive orthodontic bonding systems in white spot lesion formation: an in vitro confocal Raman microscopy analysis.
El Helou M, Albaret M, Nicolas E … +4 more , Boutin F, Younes R, Cuisinier F, Barthélemi S
Angle Orthod · 2026 Feb · PMID 41759912 · Full text
OBJECTIVES: To compare the susceptibility of enamel to white spot lesion formation following the application of two orthodontic bonding protocols: a conventional three-step adhesive system and a two-step self-adhesive sy...
OBJECTIVES: To compare the susceptibility of enamel to white spot lesion formation following the application of two orthodontic bonding protocols: a conventional three-step adhesive system and a two-step self-adhesive system with primer integrated into the resin. MATERIALS AND METHODS: Thirty extracted premolars were randomly allocated to two groups: Transbond XT (three-step system) and GC Ortho Connect (two-step self-adhesive system). After 7-day pH cycling, demineralization was assessed using Witec a300R confocal Raman microscopy. Phosphate intensity at 960 cm-1 was measured along a 130-µm enamel profile and normalized. RESULTS: Measurements by two operators showed high intraoperator and interoperator reliability (intraclass correlation coefficient = 0.82-0.92). GC samples exhibited a continuous decline in phosphate intensity, indicating extensive demineralization, while XT samples showed a midenamel plateau, suggesting mineral preservation. Spline modeling confirmed significantly higher phosphate retention in the XT group at middepth (P < .001), with both groups showing surface demineralization near 130 µm (P = .005). CONCLUSIONS: The three-step adhesive system (Transbond XT) showed greater resistance to subsurface enamel demineralization than the self-adhesive system (GC Ortho Connect). These results suggest that using a separate primer may better protect enamel beyond the immediate bracket interface.
Failure rates and associated risk factors of orthodontic-surgical treatment for impacted canines.
Zogakis IP, Anagnostou C, Ioannidou I … +2 more , Papadopoulos MA, Chaushu S
Angle Orthod · 2026 Feb · PMID 41692409 · Full text
OBJECTIVES: To determine failure rates of orthodontic-surgical treatment for maxillary and mandibular impacted canines and identify patient- and treatment-related risk factors of failure, increased duration, and need for...
OBJECTIVES: To determine failure rates of orthodontic-surgical treatment for maxillary and mandibular impacted canines and identify patient- and treatment-related risk factors of failure, increased duration, and need for surgical reintervention. MATERIALS AND METHODS: Panoramic radiographs and clinical records of patients who consecutively visited the Postgraduate Clinic of the Department of Orthodontics of the Aristotle University of Thessaloniki, Greece, were retrospectively retrieved and analyzed. Two statistical analyses were conducted, using canine and patient as units of analysis, respectively, to account for bilaterally impacted canines, resulting in multiple observations per individual. Linear and logistic regression models were employed. RESULTS: A total of 84 patients with 106 impacted canines were included. An overall failure rate of 11.3% was reported. With canine as the analysis unit, age was the only significant risk factor for failure, while both age and exposure technique were linked to the need for reintervention. In the mixed-effects regression model, age remained the only significant risk factor for both failure and reintervention. Regarding increased duration, an association was detected with increased angulation, proximity to midline, and closed exposure. CONCLUSIONS: Increased age is a significant risk factor for treatment failure and surgical reintervention of impacted canines, while greater angulation, proximity to midline, and closed over open exposure may be associated with prolonged treatment.
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