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BACKGROUND: Mandibular second premolar agenesis is a common problem in orthodontics and is often treated in conjunction with maxillary counterbalancing extractions. However, in cases without maxillary crowding or dental protrusion, space closure may pose challenges leading to compromised occlusal results or patient profile. Multiple techniques have been described to treat these patients; nevertheless, there is a paucity of data comparing effectiveness of space closure utilizing various anchorage techniques. The goal of this study is to assess the effectiveness of the Herbst device during mandibular molar protraction and compare it to the use of temporary anchorage device (TADs) in patients with mandibular second premolar agenesis. MATERIALS AND METHODS: This retrospective study included 33 patients with mandibular premolar agenesis treated without maxillary extractions. Of these patients, 21 were treated with protraction Herbst devices and 12 with TADs. Changes in molar and incisor positions, skeletal base positions and occlusal plane angulations were assessed on pretreatment (T0) and post-treatment (T1) lateral cephalograms. Scans/photographs at T0 and T1 were used to evaluate canine relationship changes representing anchorage control. Space closure and breakage/failure rates were also compared. Data was analyzed with paired and unpaired t-tests at the significance level of 0.05. RESULTS: Within the Herbst group, changes in mandibular central incisor uprighting and mandibular molar crown angulations were statistically significant. However, no significant differences were noted between the Herbst and TAD groups. Protraction rates as well as overall treatment times were comparable (0.77 mm/month vs. 0.55 mm/month and 3.02 years vs. 2.67 years, respectively). Canine relationships were maintained or improved toward a class I in 82.85% of the Herbst sample, compared to in 66.7% of the TAD sample. Emergency visits occurred in 80.1% of the Herbst group, with cementation failures or appliance breakages as the most common reasons. CONCLUSION: The Herbst device could be a viable modality in cases with missing mandibular premolars where maximum anterior anchorage is desired, or if patients/parents are resistant to TADs. Furthermore, they could be beneficial in skeletal class II patients with mandibular deficiency who also need molar protraction. However, the increased incidence of emergency visits must be considered when treatment is planned.

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OBJECTIVES: To identify whether intramaxillary miniscrew anchorage could achieve a better maxillary arch distalization effect in clear aligner treatment compared to Class II elastics. MATERIALS AND METHODS: Thirty adult patients with Class II dentition who were treated with whole maxillary arch distalization using clear aligners were collected. Either intramaxillary miniscrew anchorage (miniscrew group, n = 17) or intermaxillary Class II elastics (Class II elastic group, n = 13) were used to support maxillary arch distalization. Three-dimensional predicted and achieved displacements, and angular changes of maxillary posterior teeth and anterior teeth, were measured and compared. RESULTS: The achieved distalization efficiency was 36.2%-43.9% in the posterior teeth and the retraction efficiency was 36.9%-49.4% in the anterior teeth. No statistically significant differences were found in maxillary arch distalization efficiency between the groups. The miniscrew group achieved less incisor extrusion and posterior tooth distal tipping than the Class II elastic group. Both groups achieved comparable arch expansion, posterior tooth buccal inclination, and anterior tooth lingual inclination. CONCLUSIONS: Intramaxillary miniscrew anchorage and intermaxillary Class II elastics achieved comparable efficiency in maxillary arch distalization. However, the miniscrew anchorage showed better vertical control in anterior teeth and mesiodistal tipping control in posterior teeth.

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OBJECTIVES: To evaluate the effects of bone-anchored maxillary protraction (BAMP) treatment and longterm stability in growing cleft lip and palate and isolated cleft palate (CLP/CP) patients with mild maxillary hypoplasia and to compare maxillary growth patterns of BAMP-treated patients to matched control CLP/CP patients. MATERIALS AND METHODS: Ten patients with CLP/CP were treated with BAMP; they were compared to the maxillary growth pattern of 10 age-matched cleft control patients with no maxillary protraction treatment, who later received surgical Le Fort I maxillary advancement after the growth period. The assessment of maxillary growth and the occlusion started at mean 8 years of age and continued until mean 18 years of age. RESULTS: The use of BAMP orthopedic traction changed the growth pattern of mild hypoplastic maxilla toward a more anterior direction and advanced the face even above the level of Le Fort lll with only a minor effect on dentoalveolar units. The correction of occlusion and facial convexity were stable in the long term. CONCLUSIONS: The using BAMP may improve the position of the maxilla relative to the anterior cranial base for the correction of mild maxillary hypoplasia in adolescent patients with CLP/CP. The achieved results are rather stable in the long term.

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OBJECTIVES: To compare the buccal and palatal bone changes of maxillary posterior teeth produced by hybrid hyrax (HH) and conventional hyrax (CH) expanders in growing patients. MATERIAL AND METHODS: A sample of 32 patients with posterior crossbites in the late mixed dentition was recruited and randomly allocated into two groups. Group HH was composed of 18 individuals with a mean age of 10.7 years (six female, 12 male) treated with a hybrid expander with two anterior parasagittal miniscrews. Group CH was composed of 14 individuals with a mean age of 11.4 years (six female, eight male) treated with a conventional Hyrax expander. Cone-beam computed tomography (CBCT) exams were obtained before expansion (T1) and after 11 months when the expander was removed (T2). Buccal and palatal bone plate thickness and height of maxillary posterior teeth were measured. Intergroup comparisons were performed using t or Mann-Whitney tests (P < .05). RESULTS: The CH group showed greater decreases of the buccal bone plate height (mean change: 1.27 mm) at the maxillary first premolars compared to the HH group (mean change: 0.11 mm, P = .001). No intergroup difference was found for changes in the buccal and palatal bone thickness. CONCLUSIONS: Hybrid expanders showed a tendency to cause less negative impact on the buccal bone plate height of first premolars compared to conventional Hyrax expanders. However, the difference was not clinically significant. Both hybrid and conventional Hyrax expanders are safe for the alveolar bone morphology in the late mixed dentition.

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OBJECTIVES: To investigate the effects of transpalatal (TPA) wire dimension and temporary skeletal anchorage device (TSAD) position on maxillary molar intrusion. MATERIALS AND METHODS: The maxillary molar intrusion measurement system included a maxillary acrylic model, TPA, TSADs, and a three-dimensional Force/Moment (F/M) sensor. The intrusion patterns were categorized into six groups: buccal-mesial, buccal-distal, buccal-mesiodistal, palatal-mesial, palatal-distal, and palatal-mesiodistal. TPA wire dimensions were designed to be 0.7 mm, 0.9 mm, and 1.2 mm. The force and moment loads of the maxillary first molar were measured by the F/M sensor. RESULTS: Single buccal or palatal TSADs induced torquing movement, and single mesial or distal TSADs tended to promote tipping movement. Mesiodistal TSADs would have eliminated tipping, but accentuated torquing movement. The TPA significantly reduced the force and moment experienced by the maxillary first molar along three-dimensional axes. The thicker the TPA wire, the smaller the force and moment to which the maxillary first molar was subjected. CONCLUSIONS: Precise placement of TSADs might have a substantial influence on tooth movement and should be determined in accordance with specific clinical requirements. Increasing the TPA wire dimension could diminish the tipping, torquing, and rotation during TSAD-assisted maxillary molar intrusion, but these tendencies could not be completely eliminated.

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A bone-borne full-arch vertical control strategy using miniscrews was deployed with aligners to treat a case of skeletal hyperdivergent Class II malocclusion with bimaxillary protrusion. Miniscrews were inserted in the posterior buccal and palatal regions and the anterior buccal region of the maxilla to distribute vertical intrusive force through the upper arch by anchoring vertical elastics from the miniscrews to the aligners. Synergetic lower anterior intrusion was completed using bilateral posterior miniscrews to counteract the extrusive force generated. Substantial full upper arch and lower anterior vertical intrusion was achieved. In conjunction with en masse anterior-posterior retraction, synergetic posterior and anterior vertical intrusion facilitated counterclockwise rotation of the mandible, creating significant esthetic improvement. Anterior vertical elastics also provided flaring of the anterior teeth, reducing the side effect of lingual tipping from en masse retraction, while successfully controlling overbite and incisor torque during space closure. The bone-borne full-arch vertical intrusion strategy can work well with aligners to address hyperdivergent skeletal Class II malocclusion with bimaxillary protrusion.

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OBJECTIVES: To examine dentoalveolar changes following intrusion of maxillary incisors with one or two anterior miniscrews in subjects with gummy smile and deep bite. MATERIALS AND METHODS: Forty-three subjects were selected and divided into two groups: group I (22 subjects: 15 women, 7 men; mean age 30 ± 10 years) received one miniscrew between the upper central incisors, and group II (21 subjects: 16 women, 5 men; mean age 30 ± 10 years) received two miniscrews between the canines and lateral incisors. Dentoalveolar parameters, including amount of intrusion, root resorption, incisor inclination, alveolar bone thickness, and buccal alveolar crest height (cementoenamel junction to labial alveolar crest), were evaluated using cone-beam computed tomography scans obtained before and after intrusion. The intergroup comparison was analyzed using a paired t-test and unpaired t-test to determine significant changes within and between groups. RESULTS: The amount of intrusion was significantly greater in group II than in group I (P < .05). No statistically significant differences were found between groups I and II for changes in incisor inclination, labial bone thickness, and buccal alveolar crest height (P > .05). CONCLUSIONS: Maxillary central and lateral incisor intrusion was significantly greater in subjects treated with two miniscrews. Root resorption of the maxillary central incisors was notably greater in subjects with one miniscrew, while maxillary lateral incisor resorption was greater in subjects treated with two miniscrews.

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OBJECTIVES: To evaluate anchorage loss after en masse retraction in bimaxillary dentoalveolar protrusion patients using friction vs frictionless mechanics. MATERIALS AND METHODS: Thirty patients with bimaxillary dentoalveolar protrusion needing extraction of upper first premolars and en masse retraction with maximum anchorage were included in this two-arm, parallel, single-center, single-blinded randomized clinical trial with a 1:1 allocation ratio using fully sealed opaque envelopes. Friction group retraction utilized elastomeric power chain between miniscrews and hooks crimped mesial to upper canines on 17 × 25 stainless steel archwire. Frictionless group used customized T-loop springs loading upper first molars indirectly anchored to miniscrews. Activation was every 4 weeks until full retraction. The primary outcome assessed was anchorage loss evaluated at cusp tip and root apex of the first molar. First molar rotation, incisor tip and torque, and root resorption of anterior teeth were evaluated on digital models and cone beam computed tomography taken before and after space closure. RESULTS: Anchorage loss at crown of first molar was significantly more in frictionless group by 2.1 mm (95% CI = -0.4 to 3.5), (P = .014), while there was no significant difference in anchorage loss at root apex between groups. Significant mesial in molar rotation of 6.672° (95% CI = 12.2-21.2), (P = 0.02) was greater in the frictionless group. Both groups showed comparable tip, torque, and root resorption values. No severe harms were reported. There was mild gingival overgrowth and inflammation in the frictionless group due to T-loop irritation. CONCLUSIONS: Extra anchorage considerations are needed during en masse retraction when frictionless mechanics is implemented as higher anchorage loss and molar rotation were detected. No difference in tip, torque, and root resorption was observed.

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This article addresses the management of dental implants in joint orthodontic-restorative cases, emphasising the role of temporary skeletal anchorage devices and interdisciplinary treatment. Focused on complex malocclusions that require dental implants, the article navigates through critical aspects such as diagnosis, treatment planning, implant positioning challenges and the strategic role of temporary skeletal anchorage devices in cases with compromised anchorage. Effective communication, collaborative efforts and strategic planning are highlighted in determining optimal implant numbers, locations and timing of placement. A collaborative, strategic approach to managing the complexities of joint orthodontic-restorative cases involving dental implants is recommended.

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BACKGROUND: This study aimed to assess the effect of Low-Level Laser Therapy (LLLT) on sagittal, transverse and vertical Orthodontic miniscrew displacement. MATERIALS AND METHODS: The study included CBCTs from the records of 12 adult patients who underwent upper first premolar extraction and canine retraction with orthodontic miniscrews for maximum anchorage. The miniscrews on one side received LLL, while the other side served as a control. The Low-Level Laser was applied to assess its effect on the displacement of the miniscrews. The used CBCTs have been taken at two-time points: immediately after miniscrew insertion (T0) and four months after the start of canine retraction (T1) with a total of 24 CBCTs. Miniscrew displacement was assessed by measuring head (HMS) and tail (TMS) displacement to the axial, coronal and mid-sagittal planes on the CBCT at the two time points. Miniscrews displacement (T1-T0) was compared between LLL side and control side. Comparisons were performed using paired samples t-test. The significance level was set at p-value < 0.05. The reproducibility of measurements was assessed by intraclass correlation coefficient (ICC). RESULTS: After four months of canine retraction, HMS and TMS from both laser and control sides showed significant three-dimensional displacement at p < 0.05. No significant difference in mean displacement in the vertical, sagittal, nor transverse planes between both sides was elicited. CONCLUSION: LLL application in the used protocol does not affect the amount of miniscrew displacement in any of the three planes of space. Miniscrew displacement was significant in both groups.

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Introduction: Temporary Anchorage Devices have revolutionized our approach to anchorage management. However, their placement may carry risks, such as root perforation, damage to the periodontal ligament, buccal-nasal communication, etc. The aim of this article is to describe an original protocol in two times for the placement of a palatal mini-screw through guided surgery using a guide created by Computer-Aided Design and Manufacturing (CAD/CAM) followed by the transfer of placement information to the laboratory for the fabrication of a Custom Medical Device (CMD) for distalization. Materials and Methods: A two-stage protocol is described and illustrated step by step. Phase 1 comprises 7 steps (including superimposition of maxillary cast and profile teleradiography, surgical tray design), followed by phase 2, which involves 3 final steps (including production of impression for laboratory, production of laboratory model with transfer of mini-screw position). Results: Although the position of the mini screws remains precise, a discrepancy between the planning and the intraoral situation exists. The addition of a second step therefore enables the distalization appliance to be fitted precisely and without pitfalls. Finally, this protocol ensures safe placement, making work easier for the practitioner and, ultimately, for the patient. Conclusion: In a two-stage process, the placement of palatal mini screws through guided surgery using a guide created by CAD/CAM followed by the transfer of this information to the laboratory for the fabrication of a CMD for distalization proves to be a relevant approach.

Introduction: Les dispositifs d'ancrage temporaires ont révolutionné notre vision de la gestion de l'ancrage. En revanche, leur mise en place peut comporter certains risques (perforation radiculaire, communication bucco-nasale, lésions vasculaires…). Cet article vise à décrire un protocole original, en deux temps, de pose de mini-vis palatine par chirurgie guidée à l'aide d'un guide réalisé par conception et fabrication assistée par ordinateur (CFAO) in-office suivie du transfert des informations de pose au laboratoire pour la confection d'un appareil de distalisation. Matériel et méthodes: Un protocole en deux temps est décrit pas à pas. Le temps 1 comprend sept étapes (dont le placement virtuel des mini-vis et la création de la gouttière chirurgicale), suivi du temps 2 qui implique trois étapes (dont la réalisation de l'empreinte pour le laboratoire et l'élaboration du modèle de laboratoire avec transfert de la position des mini-vis). Résultats: Bien que la pose puisse être considérée comme précise, une différence existe entre la planification et la situation clinique. L'apport d'un second temps améliore l'adaptation de l'appareil de distalisation. Enfin, ce protocole offre une pose sécurisée et apporte ainsi un confort de travail pour le praticien et, in fine, pour le patient. Conclusion: Réalisée en deux temps, la pose de mini-vis palatine par chirurgie guidée à l'aide d'un guide réalisé par CFAO in-office suivie du transfert de cette information au laboratoire pour la confection d'un appareil de distalisation s'avère être une approche pertinente.

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PURPOSE: To compare and analyze the orthodontic effects of micro-implant screw support and flat guide plate on excessive deep overbite of lower anterior teeth. METHODS: Eighty-two patients with excessive deep overbite of the lower anterior teeth who were treated from January to December 2022 were selected and randomly divided into two groups (41 in each group) by random number table method. Both groups were treated with straight wire arch orthodontic technology, and the anterior teeth were supported by micro-implant screws (micro-implant screw group) and flat guide plates (flat guide plate group), respectively. The effect of upper anterior tooth compression, changes in occlusal plane, and apical absorption were compared between the two groups. SPSS 25.0 software package was used for statistical analysis. RESULTS: There were no significant changes in SNA angle, SNB angle, ANB angle, U1-PP, U6-PP, and L6-MP before and after treatment between the two groups (P＞0.05). L1-MP significantly increased in both groups after treatment than before treatment(P＜0.05). There was no significant difference in bite opening, Spee curve depth, U1 depression, L1 depression, U6 elongation, L6 elongation and occlusal opening time between the two groups before and after treatment(P＞0.05). The root apex absorption of the mandibular central incisors and lateral incisors in the micro-implant screw group was significantly lower than that in the flat guide plate group(P＜0.05), while there was no significant difference in root apex absorption between the two groups of canines(P＞0.05). CONCLUSIONS: Both micro-implant screw support and flat guide plate can effectively lower the mandibular anterior teeth in the treatment of deep overbite in adults, with good orthodontic effects. However, the latter can lead to increased root resorption.

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BACKGROUND: The infrazygomatic crest mini-screw has been widely used, but the biomechanical performance of mini-screws at different insertion angles is still uncertain. The aim of this study was to analyse the primary stability of infrazygomatic crest mini-screws at different angles and to explore the effects of the exposure length (EL), screw-cortical bone contact area (SCA), and screw-trabecular bone contact area (STA) on this primary stability. METHODS: Ninety synthetic bones were assigned to nine groups to insert mini-screws at the cross-combined angles in the occlusogingival and mesiodistal directions. SCA, STA, EL, and lateral pull-out strength (LPS) were measured, and their relationships were analysed. Twelve mini-screws were then inserted at the optimal and poor angulations into the maxillae from six fresh cadaver heads, and the same biomechanical metrics were measured for validation. RESULTS: In the synthetic-bone test, the LPS, SCA, STA, and EL had significant correlations with the angle in the occlusogingival direction (rLPS = 0.886, rSCA = -0.946, rSTA = 0.911, and rEL= -0.731; all P < 0.001). In the cadaver-validation test, significant differences were noted in the LPS (P = 0.011), SCA (P = 0.020), STA (P = 0.004), and EL (P = 0.001) between the poor and optimal angulations in the occlusogingival direction. The STA had positive correlations with LPS (rs = 0.245 [synthetic-bone test] and r = 0.720 [cadaver-validation test]; both P < 0.05). CONCLUSIONS: The primary stability of the infrazygomatic crest mini-screw was correlated with occlusogingival angulations. The STA significantly affected the primary stability of the infrazygomatic crest mini-screw, but the SCA and EL did not.

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OBJECTIVE: The purpose of this article is to present the MISMARPE technique, a new minimally invasive surgical procedure to treat maxillary transverse atresia in adult patients under local anesthesia and on an outpatient basis. TECHNIQUE DESCRIPTION: The technique consists of miniscrew-assisted rapid palatal expansion (MARPE) associated with a minimally invasive approach using maxillary osteotomies, latency and activation periods until the desired expansion is achieved. The present MISMARPE technique was performed in 25 consecutive cases with a success rate of 96%, yielding good skeletal outcomes with minimal trauma. The expander appliances, with their anchorage types, and a description of the surgical steps of the MISMARPE technique are presented. CONCLUSION: MISMARPE is a new and effective alternative for less invasive treatment of maxillary transverse deficiency in adults, compared to conventional surgery. Emphasis is placed on the importance of systematic and well-established protocols, for executing the procedures safely and predictably.

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OBJECTIVE: This cross-sectional study evaluated the bone thickness on mini-implants insertion site, the factors that influence the digital planning of MARPE appliance (miniscrew-assisted rapid palatal expansion), and its different designs. METHODS: A total of 135 plannings were assessed regarding the size of the expander screw used, the positioning and the type of the mini-implant rings, and their location in relation to the teeth. Bone thickness measurements were assessed in the region of the mini-implants' trajectory. Differences between the sexes was verified using the ANOVA test (5% significance). RESULTS: 73 cases were planned with 4 mini-implants and 62 cases, with 6 mini-implants. In 90% of cases, teeth #16 and #26 were used as supports, and the most used expander screw was 13mm (64.1% of cases). The anterior mini-implants of conventional MARPE showed more pronounced insertion in bone in males (5.9 ± 2mm; p= 0.025). The extra mini-implants (anterior region) were inserted with greater bone thickness in males (11.1 ± 2.3mm) compared to females (9.9 ± 1.8mm; p=0.041). A greater bone thickness was observed in males (10.1 ± 2.1 mm) when using mini-implants in the paramedian region. CONCLUSION: Additional rings allow more pronounced bone insertion. Male patients had greater bone thickness, which may be related to greater difficulty in opening the sutures. The alveolar process region seems to be a satisfactory site for mini-implants to those patients with reduced bone thickness in the paramedian posterior region. MARPE appliance must be customized for each patient, due to bone thickness and anatomical variations.

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Distalization of mandibular molars comes with significant challenges, especially in adult and young adult patients. In selected cases, third molar extraction procedures offer the opportunity to place miniplates for anchorage to distalize mandibular molars, providing additional solutions to the traditional extraction of premolars or a single incisor. This approach can be of special interest to adult patients, who may have life commitments and time restraints that limit traditional orthodontic and surgical treatment options, and it can improve the efficiency of dental care. This case series describes 3 clinical scenarios in which miniplates were placed with minimal invasiveness during the removal of impacted third molars, offering the patients nontraditional orthodontic treatment options. Awareness of these options is essential for general dentists so that they can explain all treatment possibilities and provide appropriate referrals to patients with impacted third molars.

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BACKGROUND: This study quantitatively analyzed the anatomic structure of the alveolar bone in the maxillary molar region at three potential locations for Temporary Anchorage Device (TAD) placement. Additionally, the study compared the variability in this region across different age groups, sagittal skeletal patterns, vertical facial types, and sexes. METHODS: In this retrospective cone-beam computed tomography study, the buccal alveolar bone was analyzed in the posterior molar area of 200 patients, the measurement items include buccal alveolar bone height, alveolar bone thickness, interradicular distance, and maxillary retromolar space. RESULTS: Buccal alveolar height was greatest in the U56 region. The interradicular space was largest in the U56 region and increased from the alveolar crest to the sinus floor. Buccal alveolar bone thickness was highest in the U67 region and generally increased from the alveolar crest to the sinus floor. The maxillary retromolar space gradually increased from the alveolar crest to the root apex. CONCLUSIONS: TADs are safest when placed in the buccal area between the maxillary second premolar and the first molar, particularly at the 9 mm plane. The U67 region is the optimal safe zone for TAD placement for maxillary dentition distalization. TADs placement in adolescents can be challenging. Maxillary third molar extraction can be considered for maxillary dentition distalization.

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Congenital missing second premolars in growing patients should be accurately evaluated in order to establish a suitable treatment plan. Concerning the decision of whether to close or maintain spaces in the dental arches, it shall also be based on biomechanical aspects and the aesthetic traits of individual patients. Accordingly, the option of closing tooth spaces requires an adequate application of biomechanical principles aimed at avoiding detrimental effects on dental arches and facial profile. An effective use of titanium miniscrews for immediate loading, associated with efficient sliding mechanics, can represent an elective way to successfully treat such cases. Herein, the objective is to describe the procedure and underscore the advantages of the mentioned approach by presenting a clinical case along with long-term follow-up.

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BACKGROUND: The intrusion of maxillary anterior teeth is often required and there are various intrusion modes with mini-implants in clear aligner treatment. The objective of this study was to evaluate the effectiveness of maxillary anterior teeth intrusion with different intrusion modes, aiming to provide references for precise and safe intrusion movements in clinical practice. METHODS: Cone-beam computed tomography and intraoral optical scanning data of a patient were collected. Finite element models of the maxilla, maxillary dentition, periodontal ligaments (PDLs), clear aligner (CA), attachments, and mini-implants were established. Different intrusion modes of the maxillary anterior teeth were simulated by changing the mini-implant site (between central incisors, between central and lateral incisor, between lateral incisor and canine), loading site (between central incisors, on central incisor, between central and lateral incisor, between lateral incisor and canine), and loading mode (labial loading and labiolingual loading). Ten conditions were generated and intrusive forces of 100 g were applied totally. Then displacement tendency of the maxillary anterior teeth and CA, and stress of the PDLs were analyzed. RESULTS: For the central incisor under condition L14 and for the canine under conditions L11, L13, L23, and L33, the intrusion amount was negative. Under other conditions, the intrusion amount was positive. The labiolingual angulation of maxillary anterior teeth exhibited positive changes under all conditions, with greater changes under linguoincisal loading. The mesiodistal angulation of canine exhibited positive changes under labial loading, while negative changes under linguoincisal loading except for condition L14. CONCLUSIONS: The intrusion amount, labiolingual and mesiodistal angulations of the maxillary anterior teeth were affected by the mini-implant site, loading site, and loading mode. Labial and linguoincisal loading may have opposite effects on the intrusion amount of maxillary anterior teeth and the mesiodistal angulation of canine. The labiolingual angulation of the maxillary incisors would increase under all intrusion modes, with greater increases under linguoincisal loading.

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