Orthodontic Anchorage Procedures

Just like other subjects in medicine, orthodontics also uses some vague concepts to describe what are difficult to measure quantitatively. Anchorage control is one of them. With the development of evidence-based medicine, orthodontists pay more and more attention to the accuracy of the clinical evidence. The empirical description of anchorage control is showing inadequacy in modern orthodontics. This essay, based on author's recent series of studies on anchorage control, points out the inaccuracy of maximum anchorage concept, commonly neglected points in quantitative measurement of anchorage loss and the solutions. It also discusses the limitation of maximum anchorage control.
Bone Screws ; Humans ; Orthodontic Anchorage Procedures ; Orthodontics

Humans ; Orthodontic Anchorage Procedures ; Orthodontics, Corrective

Humans ; Orthodontic Anchorage Procedures ; Orthodontic Brackets ; Orthodontics, Corrective ; methods

OBJECTIVES: This study was performed to evaluate patterns of failure time after insertion, failure rate according to loading time after insertion, and the patterns of failure after loading. MATERIALS AND METHODS: A total of 331 mini-implants were classified into the non-failure group (NFG) and failure group (FG), which was divided into failed group before loading (FGB) and failed group after loading (FGA). Orthodontic force was applied to both the NFG and FGA. Failed mini-implants after insertion, ratio of FGA to NFG according to loading time after insertion, and failed mini-implants according to failed time after loading were analyzed. RESULTS: Percentages of failed mini-implants after insertion were 15.79%, 36.84%, 12.28%, and 10.53% at 4, 8, 12, and 16 weeks, respectively. Mini-implant failure demonstrated a peak from 4 to 5 weeks after insertion. The failure rates according to loading time after insertion were 13.56%, 8.97%, 11.32%, and 5.00% at 4, 8, 12, and 16 weeks, respectively. Percentages of failed mini-implants after loading were 13.79%, 24.14%, 20.69%, and 6.9% at 4, 8, 12, and 16 weeks, respectively. CONCLUSION: Mini-implant stability is typically acquired 12 to 16 weeks after insertion, and immediate loading can cause failure of the mini-implant. Failure after loading was observed during the first 12 weeks.
Dental Implants ; Immediate Dental Implant Loading ; Orthodontic Anchorage Procedures

After tooth has been removed for a long time, adjacent teeth may tilt to occupy the edentulous space, leading to a break in the occlusal 3D equilibrium and a lack of restorative space. This case report presents a mandibular second molar uprighting with anchorage from a dental implant.
Dental Implants ; Molar ; Orthodontic Anchorage Procedures ; Tooth Movement Techniques

Adult ; Dental Implantation, Endosseous ; instrumentation ; Dental Implants ; Female ; Humans ; Orthodontic Anchorage Procedures ; instrumentation ; Orthodontic Appliance Design

OBJECTIVETo study the clinical effectiveness of implanting miniscrew serving as anchorage instead of molars in treating maxillary dental arch crowding and protrusive patients mandibular molars complete missing.

METHODSEight adult patients aged from 22 to 38, whose maxillary dental arch were crowding and protrusion, with mandibular molars missing were chosed. At the missing side, a miniscrew was implanted on the buccal surface, 11-13 mm away from the distal end of the second premolar. After implanting, a self-made miniscrew traction cap was attached to its supergingival section by keyway retention. Premolars and anterior teeth were tracted in turn to distal end. Intermaxillary traction II was made necessarily on the traction cap.

RESULTSSuccessful results were acquired after treating together with normal overbite, overjet and right occlusion relation. It took 24 months in the longest course, 15 months in the shortest course and 20.8 months on average.

CONCLUSIONThe implanting miniscrew anchorages could be used in maxillary dental arch crowding and protrusive patients with single molars complete missing.

Adult ; Bicuspid ; Bone Screws ; Cephalometry ; Dental Arch ; Humans ; Molar ; Orthodontic Anchorage Procedures ; Overbite ; Tooth Movement Techniques

OBJECTIVETo investigate the osteointegration of with self-drilling and self-tapping microscrew implants under immediate loading histomorphometrically.

METHODSThe buccal side of upper and lower jaws of three dogs was chosen as implant receipt site. Each dog accepted 8 implants (4 self-drilling and 4 self-tapping implants). Approximately 1.47-1.96 N continuous and constant forces were immediately applied between two microscrew implants with nickel-titanium coil spring for 9 weeks. Undecalcified sections of implants and surrounding tissue were studied with light microscope and fluorescent microscope.

RESULTSOsteointegration was seen in all samples and no fibrous tissue was seen between bone and implant. More original bone was seen in self-drilling group. Modeling and remodeling were more active in self-tapping group. Bone-to-implant contact values were statistically significant higher in self-drilling group [(41.7 +/- 10.7)%] than in self-tapping group [(25.9 +/- 8.0)%, P<0.01].

CONCLUSIONSImmediate loading had no influence on osteointegration in both self-drilling and self-tapping groups. The rates of bone-to-implant contact were higher in self-drilling group.

Animals ; Dental Implantation ; methods ; Dental Implantation, Endosseous ; Dental Implants ; Dogs ; Female ; Orthodontic Anchorage Procedures ; Osseointegration

OBJECTIVEThis study aims to compare the treatment outcomes in patients with maxillary dentoalveolar protrusion by applying different anchorage methods via three-dimensional model measurement.

METHODSA total of 46 patients with maxillary dentoalveolar protrusion treated with bilateral maxillary first premolar extractions and high anchorage were selected. The subjects were randomly divided into three groups according to the type of anchorage applied, which included implant, extraoral, and Nance arch anchorages. The maxillary dental models were made before treatment and after space closure of maxilla. The movements of the maxillary central incisors and first molars were measured via a three-dimensional model measurement, and the amounts of movement were compared among the three groups.

RESULTSThe sagittal lingual movements of the maxillary central incisors were (-6.661 ± 1.328), (-5.939 ± 1.806), and (-5.788 ± 2.009) mm for the implant, extraoral, and Nance arch anchorage groups, respectively, with no significant difference among the three groups (P = 0.121). The corresponding vertical movements of the maxillary central incisors were (0.129 ± 1.815) mm intrusion, and (-2.162 ± 2.026), (-2.623 ± 1.776) mm extrusion. Significant difference was found between the implant anchorage group and the other groups (P < 0.05). The corresponding sagittal mesial movements of the maxillary first molars were (0.608 ± 1.045), (1.445 ± 1.462), and (1.503 ± 0.945) mm. The corresponding vertical movements of the maxillary first molars were (0.720 ± 0.805) mm intrusion, (0.076 ± 0.986) mm intrusion, and (-0.072 ± 0.690) mm extrusion. Significant difference was found between the implant anchorage group and the other two groups (P < 0.05). In the transverse direction, the first molars all moved lingually with no significant difference among the three groups (P > 0.05).

CONCLUSIONImplant anchorage may be superior in the vertical control of the maxillary incisors and in the sagittal, as well as in the vertical control of the maxillary molars, compared with the traditional anchorages during the treatment of patients with maxillary dentoalveolar protrusion.

Bicuspid ; Cephalometry ; Humans ; Incisor ; Maxilla ; Molar ; Orthodontic Anchorage Procedures ; Tooth Movement Techniques ; Treatment Outcome