Surgical vs nonsurgical treatments in patients with anterior open-bite have similar effects in occlusal function: A 2-year follow-up study.

INTRODUCTION: This study aimed to investigate changes in bite force (BF) and occlusal contact area after anterior open-bite (AOB) treatment and compare the changes in surgical vs nonsurgical treatment. METHODS: This retrospective study included patients with AOB compared with normal occlusion. AOB was corrected by either intrusion of the maxillary molars (intrusion group, n = 19) or orthognathic surgery (surgery group, n = 37). The control group (n = 35) had a normal overbite relationship. Records of lateral cephalograms, BF, and occlusal contact area taken before (T0), immediately after (T1), and 2 years after (T2) orthodontic treatment were compared within and among the 3 groups. RESULTS: The open-bite group, including intrusion and surgery groups, had a lower BF and less occlusal contact area than the control group at T0 and T1 (P <0.001). However, there were no significant differences among the 3 groups at T2 (P >0.05). The intrusion and surgery groups showed no significant differences throughout the observation period extending from T0 to T2 (P >0.05). Although BF and occlusal contact area decreased at T1 compared with T0, they increased during retention and showed higher values at T2 than at T0. CONCLUSIONS: Treatment of AOB improved BF and occlusal contact area 2 years posttreatment. Orthognathic surgery and molar intrusion using orthodontic miniscrews can improve occlusal function similarly. Orthodontists can select either method depending on malocclusion severity and patient demand.

Treatment outcome comparison of Invisalign vs fixed appliance treatment in first premolar extraction patients.

INTRODUCTION: In this study, we compared the dentitional changes after Invisalign and conventional orthodontic treatment with 4 first premolar extractions. METHODS: This retrospective study included 57 patients whose orthodontic treatment involved the extraction of 4 first premolars because of bialveolar protrusion. A total of 27 patients were treated with Invisalign (mean age, 25.5 ± 5.2 years) and 30 patients with the fixed appliance (mean age, 24.4 ± 5.8 years). The angular and linear changes of the maxillary and mandibular central incisors, second premolars, first molars, and second molars were measured from the recordings on the basis of the lateral cephalograms taken before and after treatment. The angular changes of the canines and second premolars were measured using panoramic radiographs. RESULTS: The overbite and interincisal angle increased significantly in the Invisalign group compared with in the conventional fixed appliance group (P <0.05). The maxillary central incisors showed increased lingual tipping in the Invisalign group (P <0.05), whereas there was no statistically significant difference in the angular change of the mandibular incisors between groups (P >0.05). The maxillary first and second molars showed mesial tipping in the Invisalign group (P <0.05). The maxillary second premolars, first and second molars, and the mandibular second molars showed mesial movement in the Invisalign group (P <0.05). CONCLUSIONS: The Invisalign group showed more statistically significant lingual tipping of the maxillary central incisors, distal tipping of the maxillary canines, and mesial tipping of the maxillary first and second molars after maximum retraction of the anterior teeth compared with the fixed appliance group.

Three-dimensional evaluation of a virtual setup considering the roots and alveolar bone in molar distalization cases.

We aimed to evaluate root parallelism and the dehiscence or fenestrations of virtual teeth setup using roots isolated from cone beam computed tomography (CBCT) images. Sixteen patients undergoing non-extraction orthodontic treatment with molar distalization were selected. Composite teeth were created by merging CBCT-isolated roots with intraoral scan-derived crowns. Three setups were performed sequentially: crown setup considering only the crowns, root setup-1 considering root alignment, and root setup-2 considering the roots and surrounding alveolar bone. We evaluated the parallelism and exposure of the roots and compared the American Board of Orthodontics Objective Grading System (ABO-OGS) scores using three-dimensionally printed models among the setups. The mean angulation differences between adjacent teeth in root setups-1 and -2 were significantly smaller than in the crown setup, except for some posterior teeth (p < 0.05). The amount of root exposure was significantly smaller in root setup-2 compared to crown setup and root setup-1 except when the mean exposure was less than 0.6 mm (p < 0.05). There was no significant difference in ABO-OGS scores among the setups. Thus, virtual setup considering the roots and alveolar bone can improve root parallelism and reduce the risk of root exposure without compromising occlusion quality.

Factors influencing the successful eruption of the maxillary third molar after extraction of the maxillary second molar.

INTRODUCTION: This study evaluated the occlusal status of the maxillary third molars that erupted spontaneously after extraction of the maxillary second molars and investigated the factors that influenced the occlusal status of the maxillary third molars. METHODS: We assessed 136 maxillary third molars in 87 patients. Alignment, marginal ridge discrepancy, occlusal contact, interproximal contact, and buccal overjet were used to score the occlusal status. Occlusal status was classified as good (G group), acceptable (A group), and poor (P group) for the maxillary third molar at its full eruption (T1). The Nolla's stage, long axis angle, the vertical and horizontal position of the maxillary third molar, and the maxillary tuberosity space were assessed at the time of maxillary second molar extraction (T0) and T1 to identify factors influencing the eruption of the maxillary third molar. RESULTS: G, A, and P groups comprised 47.8%, 17.6,% and 34.6% of the sample, respectively. Age was the lowest in the G group at both T0 and T1. The maxillary tuberosity space at T1 and the amount of the change of maxillary tuberosity space were the largest in the G group. There was a significant difference in the distribution of the Nolla's stage at T0. The proportions of the G group were 60.0% in stage 4, 46.8% in stages 5 and 6, 70.4% in stage 7, and 15.0% in stages 8-10. According to multiple logistic regression analysis, stages 8-10 for the maxillary third molar at T0 and the amount of the change of maxillary tuberosity were negatively associated with the G group. CONCLUSIONS: Good-to-acceptable occlusion was seen in 65.4% of the maxillary third molars after maxillary second molar extraction. Insufficient increase in the maxillary tuberosity space and Nolla stage 8 or higher at T0 negatively influenced the maxillary third molar eruption.

The influence of age and orthodontic debonding on the prevalence and severity of enamel craze lines.

BACKGROUND: Craze lines may cause esthetic concerns, especially when noted on the incisors. Various light sources with additional recording apparatus have been proposed to visualize craze lines, but a standardized clinical protocol is yet to be determined. This study aimed to validate the application of near-infrared imaging (NIRI) from intraoral scans to evaluate craze lines and to determine the influence of age and orthodontic debonding on their prevalence and severity. METHODS: The NIRI of maxillary central incisors from a full-mouth intraoral scan and photographs from an orthodontic clinic (N = 284) were collected. The prevalence of craze lines and influence of age and orthodontic debonding history on severity were evaluated. RESULTS: Craze lines were detected reliably as white lines distinguishable from dark enamel using the NIRI from intraoral scans. The craze line prevalence was 50.7%, which was significantly higher in patients 20 years or older than in patients younger than 20 years (P < .001), with more frequent severe craze lines for those 40 years or older than in patients younger than 30 years (P < .05). Prevalence or severity was similar between patients with and without an orthodontic debonding history regardless of the type of appliance. CONCLUSION: The prevalence of craze lines in the maxillary central incisor was 50.7%, with a higher prevalence in adults than in adolescents. Orthodontic debonding did not affect the severity of craze lines. PRACTICAL IMPLICATIONS: Craze lines were reliably detected and documented by means of applying NIRI from intraoral scans. Intraoral scanning can provide new clinical information on enamel surface characteristics.

Differences in the 3-dimensional aging changes of the lips among female adults with skeletal Class I, II, and III malocclusion.

INTRODUCTION: The objective of this study was to evaluate and compare the 3-dimensional (3D) aging changes of the lips among adult skeletal Class I, II, and III malocclusion. METHODS: Female adult orthodontic patients aged 20-50 years with pretreatment cone-beam computed tomography scans were retrospectively classified according to age (20s [20-29 years], 30s [30-39 years], and 40s [40-49 years]) and then subclassified by malocclusion into skeletal Class I, II, and III relationship (9 groups; n = 30 per group). Positional differences in midsagittal and parasagittal soft-tissue landmarks and 3D morphologic aging changes of the lips were evaluated using cone-beam computed tomography scans. RESULTS: Labiale superius and cheilion for patients in their 40s indicated a significant downward and backward position compared with those in their 20s, regardless of skeletal classifications (P <0.05). Accordingly, the upper lip height decreased, and the mouth width increased significantly (P <0.05). For Class III malocclusion, the upper lip vermilion angle was greater for patients in their 40s than those in their 20s (P <0.05), whereas the lower lip vermilion angle was only lower for patients with Class II malocclusion (P <0.05). CONCLUSIONS: Middle-aged adult females (40-49 years) had a lower upper lip height and greater mouth width than those in their 20s, regardless of skeletal malocclusion. However, prominent morphologic aging changes of the lips were noted on the upper lip for skeletal Class III malocclusion and the lower lip for skeletal Class II malocclusion, implying that the underlying skeletal features (or malocclusion) may influence 3D aging changes of the lips.

Evaluation of the dimensional alternation of the alveolar bone in patients with a congenitally missing mandibular lateral incisor using cone-beam computed tomography.

INTRODUCTION: The alveolar bone is an essential consideration when planning treatment for patients with tooth agenesis. This study evaluated the changes in the alveolar bone and adjacent teeth in patients with a congenitally missing mandibular lateral incisor using cone-beam computed tomography. METHODS: Twenty-three nonorthodontically treated adults with a unilateral congenitally missing mandibular lateral incisor were the missing group (M group). The control group (C group) consisted of 23 nonorthodontically treated adults with normal occlusion and no missing teeth. First, the difference in the arch perimeter between the groups was compared at the cementoenamel junction (CEJ) level and the root apex (RA) level. Next, the root divergence of the anterior teeth in the M group was observed. Finally, the alveolar bone thickness ratio was compared between the M and C groups at different vertical levels. RESULTS: The arch perimeter was significantly decreased in the M group at the CEJ and RA levels (P <0.05). Root divergence was observed adjacent to the missing site (P <0.0001). There were a reduction in total and cancellous cortical alveolar bone thickness (ABT) ratios at the 3-, 6-, and 9-mm positions (P <0.05). The buccal cortical ABT ratios decreased at the 3-and 6-mm positions. The lingual ABT ratio increased at the 9-mm position (P <0.05). CONCLUSIONS: The congenitally missing mandibular lateral incisor caused a reduction in the arch perimeter in the CEJ area and the RA area. The root divergences were observed in the teeth adjacent to the missing areas. A significant decrease in the buccal cortical bone and cancellous bone was observed in the missing area.

Long-term follow-up of a patient with deepbite and severely resorbed maxillary central incisors treated by maxillary premolar and mandibular incisor extraction.

Deepbite is a common type of malocclusion, but it leads to difficulties in treatment and retention. We report the treatment of an adult patient with deepbite and severe crowding of teeth. Several teeth had to be restored, and the maxillary central incisors had short roots. Various treatment plans were considered, and extraction of the maxillary right and left first premolars, and mandibular right central incisor was planned. Successful treatment results were obtained with long-term retention.

Incidence and clinical risk factors associated with the development of labial protuberances after orthodontic treatment.

INTRODUCTION: Distinct, irregular, and hard, nodular labial protuberances (LPs) that were due to differential alveolar bone modeling can be noted on the labial gingival surface of the incisors after orthodontic treatment. Clinically, LPs cause patient discomfort and esthetic issues, but information on this phenomenon is limited. This study aimed to evaluate the incidence of LPs and demonstrate the etiology and clinical risk factors associated with this phenomenon. METHODS: Differential alveolar bone modeling was defined as present (+) when ≥1 distinct LPs (diameter >1 mm) developed after orthodontic treatment by comparing pretreatment and posttreatment intraoral photographs and casts of an orthodontic patient cohort treated with fixed appliances (n = 872). The incidence rate, affected sites, and their association with age, sex, and orthodontic treatment modalities were evaluated. RESULTS: The incidence rate of differential alveolar bone modeling among orthodontic patients was 3.2% (28 out of 872). The maxillary lateral incisor region was the most frequently affected site. Males (vs females) (odds ratio, 2.56 [95% confidence interval, 1.155-5.604]), adults (aged ≥ 20 years) (vs teens) (12.84 [3.003-54.866]), and those who had orthodontic extraction (vs nonextraction) (11.60 [3.434-39.156]) demonstrated significantly higher odds of developing LPs after orthodontic treatment (P <0.05). CONCLUSIONS: The incidence rate of the development of notable LPs after orthodontic treatment was 3.2%. Adult males and those who undergo orthodontic extraction have a higher risk of developing LPs. Clinicians should be aware that distinct LPs may develop when large amounts of incisal retraction are planned in adults.

Thermo-mechanical properties of 3D printed photocurable shape memory resin for clear aligners.

To overcome the limitations of the conventional vacuum thermoforming manufacturing method, direct 3D printing of clear aligners has been developed. The present study investigated the thermo-mechanical and viscoelastic properties of a photocurable resin TC-85, which is a new material for the direct 3D printed clear aligners, comparing to a conventional thermoplastic material polyethylene terephthalate glycol. Dynamic mechanical analysis was performed to analyse the mechanical behaviours of the two materials at 37 °C and 80 °C, respectively. Furthermore, the shape memory property of the two materials was evaluated using a U-shape bending test, and the shape recovery ratio for 60 min at 37 °C was calculated. The results indicate that TC-85 can constantly apply a light force to the teeth when used for the 3D printed clear aligners, owing to its flexibility and viscoelastic properties. In addition, it is expected that the force decay induced by repeated insertion of the clear aligners will be reduced and a constant orthodontic force will be maintained. Furthermore, its geometric stability at high temperatures and the shape memory properties provide advantages for the clinical application.

Morphologic changes of the incisive canal and its proximity to maxillary incisor roots after anterior tooth movement.

INTRODUCTION: The objectives were to evaluate the morphologic changes of the incisive canal (IC) and the influence of IC proximity to apical root resorption of maxillary central incisors after anterior tooth movement. METHODS: Pretreatment and posttreatment cone-beam computed tomography images of adults (aged 18-47 years) were retrospectively evaluated. Subjects were divided into control group with minimal incisor movement (n = 32; maxillary incisor tip movement <2 mm) and maximum retraction group (n = 35; maxillary incisor tip movement >4 mm). The shape, direction, morphologic changes of the IC, the proximity of the central incisor root to IC, and the amount of apical root resorption associated with the proximity after orthodontic treatment were compared. RESULTS: Changes in the shape of the IC were not observed in both control and retraction groups. However, 11.4% (4 of 35 subjects) in the retraction group indicated changes in the direction of the IC from slanted-straight to slanted-curved type after the direction of anterior retraction. The thickness of the cortical bone surrounding the IC and the distance between the incisor root and IC significantly decreased after orthodontic treatment in both groups (P <0.05). However, these changes were significantly greater in the retraction group than in control (P <0.0001). Contact or invasion of the incisor root to the IC was more prominent in the retraction group (42.8%-54.3%) than the control (10.9%-12.5%) (P <0.0001). The amount of root resorption indicated a tendency to increase in the order of separation, approximation, contact, and invasion in relation to IC. CONCLUSIONS: Although remodeling of IC was evident in some patients, contact or invasion of the maxillary central incisor roots to IC was fairly high after maximum anterior retraction.

Incisive canal remodelling following maximum anterior retraction reduces apical root resorption.

INTRODUCTION: The objectives were to visualize the incisive canal (IC) remodelling following maximum incisor retraction and to evaluate its impact on canal-invasion-associated apical root resorption. METHODS: Pre- and post-treatment CBCT images of 34 adult orthodontic patients (age 18-47 years) with a large amount of maxillary incisor retraction (>4 mm) using temporary anchorage devices (TADs) were retrospectively evaluated. Maxillary regional superimpositions and 3D models of the IC along with central incisors were used to measure the changes in IC dimension, IC invasion by the roots and IC remodelling. In addition, the association of the amount of apical root resorption with the root-IC relationship and IC remodelling were evaluated. RESULTS: IC invasion by the incisor roots following maximum retraction was seen in 53% (18 out of 34) of the cases. IC with larger volume and area showed more invasions compared with those with smaller volume and area (P < .01). The amount of root resorption was significantly higher with IC invasion than without invasion (2.39 mm vs 0.82 mm, P < .0001). IC remodelling following maximum retraction was seen in 24% of the subjects. IC remodelling group demonstrated less apical root resorption than the non-remodelling group (0.98 mm vs 3.27 mm, P < .0001). CONCLUSION: IC with larger volume and surface area before treatment were more likely to show canal invasion by the incisor roots after maximum retraction. IC invasion resulted in apical root resorption. However, approximately one-fourth of cases showed remodelling of the IC, which reduced the amount of root resorption.

Nonsurgical treatment of an adult with a skeletal Class III malocclusion combined with a functional anterior shift, severely overclosed vertical dimension, and a reverse smile.

This case report illustrates the successful nonsurgical treatment of an adult with a skeletal Class III malocclusion exacerbated by a functional anterior shift that resulted in a severe overclosure of the mandible and a reverse smile line. To maximize the soft tissue and smile esthetics while idealizing the occlusion, active clockwise rotation of the mandible was induced along with mandibular molar uprighting and sequential leveling. In the maxilla, full arch distalization was achieved after second molar extraction. The treatment provided a satisfying esthetic and functional outcome and has remained stable.

Posterior dental compensation and occlusal function in adults with different sagittal skeletal malocclusions.

OBJECTIVE: The aim of this study was to compare posterior tooth inclinations, occlusal force, and contact area of adults with different sagittal malocclusions. METHODS: Transverse skeletal parameters and posterior tooth inclinations were evaluated using cone beam computed tomography images, and occlusal force as well as contact area were assessed using pressure-sensitive films in 124 normodivergent adults. A linear mixed model was used to cluster posterior teeth into maxillary premolar, maxillary molar, mandibular premolar, and mandibular molar groups. Differences among Class I, II, and III groups were compared using an analysis of variance test and least significant difference post-hoc test. Correlations of posterior dental inclinations to occlusal function were analyzed using Pearson's correlation analysis. RESULTS: In male subjects, maxillary premolars and molars had the smallest inclinations in the Class II group while maxillary molars had the greatest inclinations in the Class III group. In female subjects, maxillary molars had the smallest inclinations in the Class II group, while maxillary premolars and molars had the greatest inclinations in the Class III group. Occlusal force and contact area were not significantly different among Class I, II, and III groups. CONCLUSIONS: Premolar and molar inclinations showed compensatory inclinations to overcome anteroposterior skeletal discrepancy in the Class II and III groups; however, their occlusal force and contact area were similar to those of Class I group. In subjects with normodivergent facial patterns, although posterior tooth inclinations may vary, difference in occlusal function may be clinically insignificant in adults with Class I, II, and III malocclusions.

The effect of cetirizine, a histamine 1 receptor antagonist, on bone remodeling after calvarial suture expansion.

OBJECTIVE: The objective of this study was to evaluate the effects of cetirizine, a histamine 1 receptor antagonist, on bone remodeling after calvarial suture expansion. METHODS: Sixty male Sprague-Dawley rats were divided into 4 groups; the phosphate-buffered saline (PBS)-injected no expansion group, cetirizine-injected no expansion group, PBS-injected expansion group, and cetirizine-injected expansion group, and were observed at 7, 14, and 28 days. Five rats per group were examined at each observation day. Daily injections of cetirizine or PBS were administered to the relevant groups starting 2 weeks prior to expander insertion. A rapid expander was inserted in the calvarial bone to deliver 100 cN of force to the parietal suture. The specimens were prepared for hematoxylin and eosin and tartrate-resistant acid phosphatase (TRAP) staining. Suture opening and bone regeneration were evaluated using microcomputed tomography and bone histomorphometric analysis. Serum blood levels of osteocalcin and carboxy-terminal collagen crosslinks (CTX) were also evaluated. RESULTS: TRAP-positive cell counts and CTX levels decreased while osteocalcin levels increased in the cetirizine-injected expansion group at observation day 28. In the expansion groups, the mineralized area gradually increased throughout the observation period. At day 28, the cetirizine-injected expansion group showed greater bone volume density, greater mineralized area, and narrower average suture width than did the PBS-injected expansion group. CONCLUSIONS: Cetirizine injection facilitated bone formation after suture expansion, mostly by suppressing osteoclastic activity. Histamine 1 receptor antagonists may aid in bone formation after calvarial suture expansion in the rat model.

A longitudinal comparison of body height growth of orthodontically treated Class I and Class III adolescents compared with the general population.

INTRODUCTION: The aim of this study was to evaluate the height growth of Class I and III orthodontic patients according to the Fishman skeletal maturation index (SMI) and to compare it with that of a general population. METHODS: The study sample included 81 Class I and 71 Class III adolescents who had height measurements and hand-wrist radiographs taken annually and categorized according to SMI. Height completion rate, residual height, height increase per sequential SMI stage, and height velocity were analyzed. Sex differences were evaluated and comparisons between Class I and Class III groups were made. In addition, the height of orthodontic patients was indirectly compared with that of the general population. RESULTS: In boys and girls, height completion rate was >90% at SMI 6, residual height was fewer than 10 cm at SMI 7, and height increase per sequential SMI stage was greatest from SMI 6 to SMI 7. Height velocity was greatest from SMI 5 to SMI 6 in boys and from SMI 4 to SMI 5 in girls. CONCLUSIONS: There was no significant difference in body height parameters for all SMI stages between Class I and Class III adolescents. Adolescents who had orthodontic treatment were not shorter in stature at growth completion compared with the general population.

Periodontal and root changes after orthodontic treatment in middle-aged adults are similar to those in young adults.

INTRODUCTION: The goal of this study was to compare the outcomes and amount of change in periodontal health of anterior teeth in young versus middle-aged adults, who were treated to improve anterior alignment and occlusion. METHODS: Pre- and posttreatment records including orthodontic casts, cephalograms, and standardized periapical radiographs were retrospectively collected from young adults (aged 19-30 years; n = 12) and middle-aged adults (aged ≥40 years; n = 27). Following the American Board of Orthodontics criteria, discrepancy index (DI), cast-radiograph evaluation (CRE), treatment duration (TD), marginal bone loss (MBL), and tooth length (TL) were measured, and with the use of periapical radiographs, changes in the level of marginal bone (MBC) and the amount of root resorption (RR) after orthodontic treatment were calculated. RESULTS: DI, MBL, and TD were significantly higher in the middle-aged adults than in the young adults (P < 0.05). However, CRE and MBC after treatment were similar between the 2 groups (P > 0.05). The mean amount of RR following treatment was -0.6 ± 0.44 mm and -1.0 ± 0.61 mm in young and middle-aged adults, respectively. The degree of RR after compensating for treatment complexity and TD was similar between the 2 groups (P > 0.05). CONCLUSIONS: Although the initial malocclusion and periodontal conditions were unfavorable for the middle-aged adults, the overall treatment and periodontal outcomes after orthodontic treatment of the anterior teeth were similar to those for young adults. It appears that older adults tolerate orthodontics to improve the appearance of the anterior teeth as well as younger adults, with no additional burden because of their increased age.

Differential alveolar bone modeling after orthodontic retraction.

BACKGROUND: Distinct, irregular, and hard nodular protuberances similar to the morphologic features of exostoses can occasionally be noted on the labial surface of the alveolar bone after orthodontic retraction of anterior teeth in adults. These have long been believed to be exostoses developed in response to loading. However, specific characterization of this phenomenon has not been documented. CASE DESCRIPTIONS: Three cases of patients displaying multiple irregular labial bony protuberances after retraction of anterior teeth are reported. These protuberances appeared during retraction and became more prominent with additional retraction. Serial clinical photographs, lateral cephalograms, digital models, and cone-beam computed tomography scans were evaluated. On the basis of 3-dimensional superimpositions of digital models and cone-beam computed tomographic scans, the irregular protuberances appear to be the result of differential alveolar bone modeling, with more resorption of bone covering the tooth root than that of interdental bone, and not of true bone overgrowth or deposition (that is, exostoses). CONCLUSION AND PRACTICAL IMPLICATIONS: Orthodontic patients often seek treatment to improve occlusion as well as esthetics. Although this study shows that these protuberances are the result of differential modeling, they may still be perceived by patients as "outgrowths," which may cause concerns related to esthetics or comfort. Clinicians should note that these protuberances are a possible outcome when large amounts of bodily retraction and root movement of anterior teeth are planned. Patients who experience psychosocial problems with this phenomenon may be candidates for alveoloplasty.

Anchorage loss assessment of the indirect anchor tooth during adjunctive orthodontic treatment.

INTRODUCTION: This study quantitatively assessed movement of anchor teeth connected to a miniscrew (indirect anchor tooth) and investigated factors affecting movement during adjunctive orthodontic treatment. METHODS: Dental plaster models of 28 patients whose treatment included an indirect anchor tooth on one side were collected before and after treatment. The casts were digitally scanned, and 2 groups were constituted: the indirect anchor teeth (experimental group; n = 52) and the untreated teeth (control group; the first and second premolars opposing the indirect anchor tooth to which no orthodontic force was applied; n = 55). Pretreatment and posttreatment models were superimposed and the amount and direction of indirect anchor tooth movement were evaluated with the use of a univariate linear mixed model. Possible factors affecting movement of the indirect anchor tooth and its significance were also evaluated with the use of a multiple linear mixed model. RESULTS: The indirect anchor tooth moved 0.91 ± 0.50 mm and did not exhibit significant differences in the transverse, vertical, or sagittal directions. The location of the indirect anchor tooth affected movement and the tooth moved significantly more in the mandible than in the maxilla. CONCLUSIONS: The indirect anchor tooth can move during adjunctive orthodontic treatment and thus requires careful monitoring for occlusal changes.