Orthodontic treatment is a time-consuming process whose duration usually takes 2-3 years. In general, long-term treatment duration possesses higher risks of complications, which may have adverse impact on patients. Therefore, exploring safe and effective adjunctive interventions to accelerate orthodontic tooth movement and shortening the treatment duration are of profound clinical significance. Currently, numerous adjunctive interventions have been generated and developed to accelerate orthodontic tooth movement, which can be divided into two main categories: surgical and non-surgical. However, an intervention that is widely accepted as a routine practice in orthodontic clinic is lacking. This article aims to review com-mon adjunctive interventions used to accelerate orthodontic tooth movement. This review can be used as a basis to guide clinical practice, shorten treatment duration, and improve patients' prognosis.
Humans ; Tooth Movement Techniques

Background: Orthodontic tooth movement occurs due to bone resorption and apposition on the pressure and tension side of the PDL. The transcription factors associated with osteoclast differentiation are NFATc1 while osteoblast differentiation is associated with RUNX2. The optimum force of orthodontic tooth movement can move the teeth to the desired position, without causing discomfort and tissue damage to the patient. Objective: This study aims to analyse the effect of gradually increasing force on orthodontic tooth movement (by evaluating the NFATc1 and RUNX2 expression) in rats. Methods: This research is an in vivo experimental study with a post-test control group design. Twenty-eight healthy male adult Wistar rats (Rattus novergicus) aged 4-5 months with body weights 200-250 g rats were divided into seven study groups. Treatment groups in this study are given the force (by applying a closed coil spring between the maxillary central incisor and the maxillary first molar) of 5 g, 5-10 g, 10 g, and 10-20 g with the duration of treatment in 14 and 28 days. After the treatment day was finished, the alveolar bone tissue was isolated and investigated by immunohistochemical methods. Results: Indicate a significant difference between the control and all treatment groups of NFATc1 (p=0.003; p=0.000; p:0.010; p=0.001; p=0.001; p=0.000) and RUNX2 with groups of 10 g/14 days, 10 g/28 days, 5 g/28 days, 10 g/14 days,10-20 g/28 days (p=0.001; p=0.000; p=0.000; p=0.017; p=0.014; p=0.000) values. Conclusion Gradually increasing force affects orthodontic tooth movement by inducing bone resorption (high expression of NFATc1) in the pressure area and bone apposition (high expression of RUNX2) in the tension area. Applying heavy force by initially applying light force could inhibit hyalinization.
Orthodontic Tooth Movement ; Tooth Movement Techniques

The structural theory and fabrication of a self-designed rotating auxiliary spring in edgewise technique were described. Rotating auxiliary spring was applied to correct rotated tooth in clinic. It indicated that rotating auxiliary spring was an easy-fabricated, convenient-manipulated device, and could produce an effective treatment results in correcting rotated tooth, especially in the final adjustment stage.
Humans ; Malocclusion ; Tooth Movement Techniques

The bracketless invisible aligner technique has been considered as a new developed orthodontic technique since its appearance during the period of late 1990s. It is characterized with the advantages of more aesthetic, comfortable, simple, high-efficient and predictable compared with current traditional orthodontic techniques depending on brackets and wires for orthodontic tooth movements. There have been many opportunities for further development and clinical application for the technique with the developments of material sciences, computer software and hardware technology, rapid prototyping techniques, et al. Nevertheless, kinds of difficulties and challenges have been and should be met either at present or in the future for this relatively new technique which just occurred around 10 years ago. The histories, developments with opportunities and challenges and prospects of the technique will be reviewed and discussed in this paper.
Humans ; Orthodontic Appliances ; Tooth Movement Techniques

ABSTRACT The goal of this study was to investigate differences in alkaline phosphatase (ALP) levels in young and old rabbits after administering the soybean isoflavone genistein during orthodontic tooth movement. Twelve rabbits were used and assigned to four groups (n = 3); OG (old rabbits), OGS (old rabbits + soybean), YG (young rabbits), and YGS (young rabbits + soybean). The rabbit mandibulary incisors were distalised using a nickel-titanium open coil spring (50 g force). Genistein was administered from the initial orthodontic force delivery until day 21, at a dose of 1.2 mg/kg BW once a day. ALP levels (U/mg) were measured on days 1, 7, 14, 21 after orthodontic force delivery using a UV-Vis 6300 spectrophotometer at a 405 nm wavelength. The results were analysed by one-way analysis of variance followed by Tukey’s Honest Significant Difference (HSD) test (p < 0.05). The ALP levels between the young and old age groups were significantly different. ALP levels were highest in the YGS group, and significantly lowest in the OG group (p < 0.05). Moreover, the ALP level of the OGS group was significantly higher than that in the OG group (p < 0.05). In conclusion, daily consumption of soybean isoflavone genistein could enhance ALP levels during orthodontic tooth movement, particularly in older rabbits.
Alkaline Phosphatase ; Tooth Movement Techniques ; Rabbits

OBJECTIVETo investigate the relationship between apical root resorption and orthodontic tooth movement in growing subjects.

METHODS58 growing subjects were collected randomly into the study sample and another 40 non-treated cases were used as control. The apical resoption of the upper central incisors was measured on periapical film and the incisor displacement was measured on lateral cephalogram. Using multiple linear regression analysis to examine the relationship between root resoption and the displacement of the upper incisor apex in each of four direction (retraction, advancement, intrusion and extrusion).

RESULTSThe statistically significant negative association were found between resorption and both intrusion (P < 0.001) and extrusion (P < 0.05), but no significant association was found between resorption and both retraction and advancement. The regression analysis implied an average of 2.29 mm resorption in the absence of apical displacement.

CONCLUSIONSThe likelihood that the magnitude of displacement of the incisor root is positively associated with root resoption in the population of treated growing subjects is very small.

OBJECTIVETo analyze the practical effect of distalization of lower cuspiud by light-segmented archwire.

METHODS17 cases were selected. In all cases, two lower first bicuspids were extracted and lower molars were designed as reinforced anchorage. In the first half year, lower cuspids were distalized with light-segmented archwire, and lower incisors were in the physiologic drift stage. Before the treatment, three months and six months after the treatment, cephalograms and study models were recorded respectively. The data were analyzed with SPSS 10.0.

RESULTSThe distance of mesiolization of the first lower molar was 1.14 mm in half a year. The distance of distalization of the lower cuspid was 5.02 mm in half a year. No significant difference was found in LM-MP and SN-MP angle. LI-NB angle was decreased by 9.57 degrees. Crowding of lower incisors was transferred from -2.55 mm to 1.08 mm.

CONCLUSIONDuring distalization of lower cuspid by light-segmented archwire, anchorage tooth was stable, lower cuspids were distalized effectively, and lower incisors drifted towards the ideal position automatically.

OBJECTIVETo explore certain principle of how osteoprotegerin (OPG) and osteoprotegerin ligand (OPGL) take part in the periodontal tissues remodeling under the combined influence of inflammation and orthodontic force.

METHODSThe positive signals of OPG and OPGL mRNA were measured with in situ hybridzation after orthodontic tooth movement in the experimental periodontitis groups and control ones.

RESULTSThe OPG and OPGL mRNA expression intensity in the experimental group showed difference from control. All their optical density index reached a peak in day 2, respectively.

CONCLUSIONOPG and OPGL play important roles in the periodontal reconstruction induced by inflammation irritation and orthodontic force, and complex interaction could exist between the two factors.

Contemporary orthodontic care should be a team approach to achieve health and esthetics of soft and hard tissue. It should be given enough attention that periodontal health provides the foundation for tooth movement, and that distinct esthetic results can be achieved by subtle changes in tooth alignment and gingival contours. Orthodontic treatment planning should include evaluation of gingival health and esthetics to anticipate the need for interdisciplinary approaches. Studies on the effect of orthodontic treatment on gingiva can provides basis for maintaining gingival health and esthetic. This article will focus primarily on the gingival health and esthetic care in orthodontic treatment.
Esthetics ; Esthetics, Dental ; Gingiva ; Humans ; Tooth Movement Techniques

OBJECTIVES: At present, the research on clear aligner of molar distalization mainly focuses on the upper jaw, while the research on mandibular molars is few.This study aims to evaluate the therapeutic effect of mandibular molars distalization with clear aligner via cone beam CT (CBCT) and Dolphin software. METHODS: Twenty cases of mandibular molars with clear aligner were included according to the inclusion and exclusion criteria. CBCT was taken before treatment (T0) and when the first molar was moved in place (T1). Dolphin software was used to measure the effectiveness of molar distalization. Three-dimensional changes in direction and the impact on the incisors and facial soft and hard tissues were evaluated. RESULTS: The effective rates of crown and root distalization of the second and first mandibular molars were 74%, 49%, and 71%, 47%, respectively. The second and first molars were both the distal buccal cusp with the largest distalization [(2.15 ± 0.91) mm and (1.85±1.09) mm], respectively, with significant difference between the T0 and T1 ( CONCLUSIONS Clear aligner can effectively move mandibular molars farther, the crown is more effective than the root, and it is tilted. The second mandibular molar is more effective than the first mandibular molar in its distant displacement and three-dimensional changes. Molar distalization causes minor changes in mandibular incisors and facial soft and hard tissues.
Cephalometry ; Maxilla ; Molar ; Orthodontic Appliances, Removable ; Tooth Movement Techniques