Objectives: To evaluate quantitatively the relationship between molar intrusion (change [Δ] maxillary first molar [U6]-palatal plane [PP]) and changes in vertical and sagittal cephalometric parameters and to determine the center of mandibular autorotation.
Materials And Methods: Twenty-one patients diagnosed with anterior open bite and successfully treated with molar intrusion (overbite [OB] > 0 mm) were retrospectively enrolled. Lateral cephalograms taken before and after molar intrusion were used to measure changes in vertical and sagittal cephalometric parameters. The center of mandibular autorotation was calculated by measuring displacement of gonion (Go) and pogonion (Pog). Paired t-tests were used to compare variables, and linear regression analysis was used to examine the relationship between ΔU6-PP and other variables.
Results: The mandible exhibited counterclockwise rotation after maxillary molar intrusion, which led to closure of anterior open bite. Strong linear relationships, in descending order, between ΔU6-PP and ΔOB, Δanterior facial height (AFH), Δvertical reference plane (Pog), and Δsella-nasion to Go-menton (SN-GoMe), were observed. When the maxillary molar was intruded 1 mm, OB increased by 2.6 mm, AFH decreased by 1.7 mm, Pog moved forward by 2.3 mm, and SN-GoMe decreased by 2°. The center of mandibular autorotation was located 7.4 mm behind and 16.9 mm below condylion after molar intrusion.
Conclusions: The mandible exhibited counterclockwise rotation after maxillary molar intrusion; the center of mandibular autorotation was located behind and below condylion with individual variations.
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http://dx.doi.org/10.2319/102317-714.1 | DOI Listing |
Int Orthod
January 2025
Private Practice, Osaka, Japan.
This case report describes a complex full-step asymmetrical Class II division 1 high-angle in an adult patient treated by extraction of compromised first molars with a preadjusted lingual appliance. Since the patient presented severe sagittal and vertical discrepancies combined with an Izard orthofrontal profile with upper lip protrusion, an extraction camouflage was performed with the twofold aim of obtaining ideal occlusal relationship and profile improvement, correcting occlusal plane cant by selective intrusion with interradicular miniscrews. Appropriate biomechanical strategies, including extraction choice and anchorage control during space closure, were needed to achieve the planned results.
View Article and Find Full Text PDFJ Orthod Sci
November 2024
Department of Orthodontics and Pedodontics, Faculty of Dentistry, Van Lang University, Binh Thanh District, Ho Chi Minh City, Vietnam.
Objectives: To evaluate the effectiveness of mini-implant (MI) anchorage versus conventional anchorage for the treatment of skeletal class II malocclusion.
Materials And Methods: The study was conducted on 64 patients with skeletal class II malocclusion. The patients were divided into two groups: 1) 32 patients underwent conventional anchorage, and 2) 32 patients underwent MI anchorage.
Am J Orthod Dentofacial Orthop
December 2024
Discipline of Orthodontics, School of Dentistry, Faculty of Medicine and Health, The University of Sydney, Sydney, Australia; Department of Orthodontics, Sydney Dental Hospital, Sydney Local Health District, Sydney, Australia; Division of Orthodontics, University Clinics of Dental Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland. Electronic address:
Introduction: The dentoskeletal effects of clear aligner treatment (CAT) with Invisalign vs temporary skeletal anchorage device-anchored Sydney intrusion spring (SIS) were compared in consecutively treated growing patients with anterior open bite using cone-beam computed tomography scans.
Methods: Fifteen adolescents treated exclusively with Invisalign, and 14 with SIS (first-phase treatment) were assessed retrospectively. Rigid-wise, voxel-based registration of pretreatment and posttreatment cone-beam computed tomography scans were performed using the anterior cranial base, maxillary plane, and mandibular body as reference regions.
Eur J Orthod
December 2024
Department of Dentistry, All India Institute of Medical Sciences, Basni Industrial Area Phase-2, Jodhpur- 342005, Rajasthan, India.
Orthod Craniofac Res
November 2024
Department of Orthodontics, State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China.
Objective: This study aimed to evaluate the effects of molar attachment orientation and designed molar vertical movement on molar distalisation using clear aligners. Specifically, the study focused on the impact of vertical forces during upper second molar distalisation.
Materials And Methods: A three-dimensional finite element analysis was conducted to simulate upper molar distalisation using clear aligners.
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