Orthodontic Anchorage Procedures

Humans ; Orthodontic Anchorage Procedures ; Orthodontics, Corrective

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 ; 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 evaluate the efficiency of micro-implant anchorage (MIA) for posterior teeth intruded and the result of the treatment of scissors bite on one-side posterior teeth.

METHODSThe study included 3 females and 1 male. All the overextruding upper posterior teeth were intruded by the MIA. The micro-implant screws were inserted into the buccal and lingual alveolar hone of the maxillary posterior teeth or the buccal alveolar hone of mandibular posterior teeth. About 0.833 N force was used to intrude the overgrowthing upper posterior teeth, and about 0.559 N force was used to draw buecally the low posterior teeth tilting lingually.

RESULTSThe overextruding upper posterior teeth were intruded 2.0 mm on average, the low posterior teeth tilting lingually were upreared buccally. All the MIA screws kept stable during the treatment, but there was a slight inflammation around the implant screws.

CONCLUSIONMIA could be used as an efficient method to correct scissors bite on one-side posterior teeth with intruding overgrowth upper posterior teeth, or uprearing buccally the tilting low posterior teeth.

OBJECTIVEThis study aims to biomechanically analyze a mini-implant at different healing times before loading.

METHODSSixty-four mini-implants with (12 +/- 1) N x cm insertion torque were placed in the low jaw of eight beagle dogs. The test mini-implants remained in the low jaw for 0, 1, 3, and 8 weeks of bone healing and for an additional 10 weeks under a force of 0.98 N. The unloaded control implants were further divided into four groups (1, 3, 8, and 10 weeks). Maximum removal torque (MRT) testing was performed to evaluate the interfacial share strength of each group. Surface analysis of the removed implants was performed by scanning electric microscope (SEM).

RESULTSThe MRT for the loading implants at 0, 1, 3, and 8 weeks of healing were 4.10, 4.25, 2.42, and 4.42 N x cm, respectively. During the healing process, the removal torque values of the 3-week implants were significantly lower than those of the other healing groups (P < 0.05). The unloaded 3-week implants also had lower removal torques (P < 0.05). The implant surface of the 3-week test group showed more fibrous bone. However, the other loading implants had more lamellar-like tissue.

CONCLUSIONA stable dangerous period occurred approximately 3 weeks after mini-implant insertion. A 3-week healing is disadvantageous to the stability of the implant. Orthodontics loading occurred immediately or after 1 week as a function of the healing time. The 8-week implant appeared to have a positive effect on peri-implant bone remodeling and implant stability.

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.