scholarly journals Does anchorage loss differ with 0.018-inch and 0.022-inch slot bracket systems?

2019 ◽  
Vol 89 (4) ◽  
pp. 605-610
Author(s):  
Yassir A. Yassir ◽  
Grant T. McIntyre ◽  
Ahmed M. El-Angbawi ◽  
David R. Bearn

ABSTRACT Objectives: To compare maxillary first molar anchorage loss between 0.018-inch and 0.022-inch slot fixed appliance systems. Materials and Methods: Patients requiring bilateral maxillary premolar extractions (n = 74) within a randomized clinical trial comparing the effectiveness of 0.018-inch and 0.022-inch slot MBT bracket systems (3M-Unitek, Monrovia, Calif) were included. Three-dimensional pre- and posttreatment digital models were landmarked and measured (R700 scanner and OrthoAnalyzer software, 3Shape, Copenhagen, Denmark). Anteroposterior position of the first molars was measured using the third medial rugae point as a reference. Anchorage loss (AL) represented the subtraction of the posttreatment distance from the pretreatment distance for both anchorage loss right (ALR) and left (ALL) sides. The values were then compared using a two-way analysis of variance. Results: There were 41 and 33 cases for the 0.018-inch and 0.022-inch bracket slot systems, respectively. The baseline characteristics were similar between groups, except for the presence or absence of anchorage devices (P = .050). For the total sample: 0.018-inch ALR = 3.86 mm, ALL = 3.30 mm and 0.022-inch ALR = 3.73 mm, ALL = 3.47 mm (P = .970). There was also no significant difference between the 0.018-inch and 0.022-inch groups when subjects with anchorage devices were excluded (P = .383). Conclusions: Bracket slot size does not influence maxillary molar anchorage loss during orthodontic treatment.

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Fei Teng ◽  
Fei-Yu Du ◽  
Hui-Zhong Chen ◽  
Ruo-Ping Jiang ◽  
Tian-Min Xu

Abstract We assessed the three-dimensional (3D) pattern of the physiologic drift of the remaining adjacent teeth after premolar extraction due to orthodontic reasons and the associated factors. Data were collected from 45 patients aged 17.04 ± 5.14 years who were scheduled to receive a fixed appliance after maxillary premolar extraction. Seventy-five drift models were obtained and digitalized via 3D scanning. The average physiologic drift duration was 81.66 ± 70.03 days. Angular and linear changes in the first molars, second premolars, and canines were measured using the 3D method. All the examined teeth had tipped and moved towards the extraction space, leading to space decreases. Posterior teeth primarily exhibited significant mesial tipping and displacement, without rotation or vertical changes. All canine variables changed, including distal inward rotation and extrusion. The physiologic drift tended to slow over time. Age had a limited negative effect on the mesial drift of posterior teeth, whereas crowding had a limited positive effect on canine drift. Thus, the mesial drift of molars after premolar extraction may lead to molar anchorage loss, particularly among younger patients. The pattern of the physiologic drift of maxillary canines can help relieve crowding and facilitate labially ectopic canine alignment, whereas canine drift is accelerated by more severe crowding.


2020 ◽  
pp. 030157422096350
Author(s):  
Ajit Vikram Parihar ◽  
Shivam Verma ◽  
TP Chaturvedi ◽  
Naresh Kumar ◽  
A Kavin Prasanth ◽  
...  

Introduction: The objective of the study was to assess the rate of canine retraction and secondary outcomes associated with conventional fixed orthodontic treatment (CFO) and CFO with micro-osteoperforation (CFO + MOP), that is, anchorage loss, root resorption, vitality of tooth, pain and discomfort level during the procedure. Methods: A total of 16 patients with Class II Division 1 malocclusion who required upper first premolar extraction with lower non-extraction/single incisor extraction were divided into the test group (MOP) and positive control group (CFO + MOP) for a split-mouth study. Both maxillary canines were retracted with nickel–titanium (NiTi) closed coil springs. Patients were reviewed after 24 hours, 7 days, 28 days, and 4, 8, and 16 weeks to assess the rate of tooth movement, anchorage loss, root resorption, vitality of tooth, pain and discomfort level. Results: There was a statistically significant difference in the rate of tooth movement between the CFO and CFO + MOP groups after the first 4 weeks ( P-value = .026), whereas no statistically significant difference was observed at 8, 12, and 16 weeks ( P-value = .33, .99, and .08, respectively). In the CFO group, there was no statistically significant difference in tooth movement between different time intervals ( P-value > .05). There was no significant difference in root resorption between the groups. The pain level was higher in the MOP group in the first 24 hours ( P-value < .05) after the procedure. Later on, the difference in pain level between the groups was not significant ( P-value > .05). The vitality of retracted canines in both groups was healthy. Conclusion: The study recommends that the CFO + MOP procedure has substantial potential to be used as an adjunct to the routine mechanotherapy for faster tooth movement, as it may reduce the treatment time by half in the first 4 weeks after the MOP procedure. There are no potential differences in anchorage loss, tipping, vitality, and apical and lateral root resorption between the CFO and CFO + MOP groups. This trial was registered at Clinical Trial Registry, India.


Author(s):  
Mohammed Fahad Parvez ◽  
Nandini Manjunath ◽  
Raghavendra Kini

Background: Radiographs in periodontics will provide a two-dimensional image of a three-dimensional object and this leads to problems in terms of validity, accuracy and precision. Hence, the study was conducted with an aim to assess the accuracy of IOPA And CBCT for Maxillary Molar Furcation involvement by clinical and radiological methods.Methods: The study sample consisted of 17 subjects from the Out patient Department of A.J. Institute of Dental Science, Manglore belonging to both sexes and with age ranging from 35-55 years. The selected patients were those having presence of periodontal pockets of >5-6mm and advanced periodontal disease requiring surgical intervention. For the purpose of standardization, 3 sites of the maxillary first molars were assessed-Mid-buccal, Mesio-buccal, Disto-buccal. Iopa and CBCT measurements were taken which was followed by surgical intervention during which probing measurements were recorded. Statistical analysis was done using ‘unpaired t test’.Results: There was no statistically significant difference between CBCT measurements and surgical measurements (p≤0.05).Conclusions: CBCT accurately reproduced the clinical measurement of periodontal bone defects.


2006 ◽  
Vol 76 (6) ◽  
pp. 923-929 ◽  
Author(s):  
Ingela Karlsson ◽  
Lars Bondemark

Abstract Objective: To evaluate the maxillary molar distalization and anchorage loss in two groups, one before (MD 1 group) and one after (MD 2 group) eruption of second maxillary molars. Materials and Methods: After a sample size calculation, 20 patients were recruited for each group from patients who fulfilled the following criteria: no orthodontic treatment before distal molar movement, Class II molar relationship defined by at least end-to-end molar relationship, space deficiency in the maxilla, and use of an intra-arch NiTi coil appliance with a Nance appliance to provide anchorage. Patients in the MD 1 group were without any erupted second molars during the distalization period, whereas in the MD 2 group both the first and second molars were in occlusion at start of treatment. The main outcome measures to be assessed were: treatment time, ie, time in months to achieve a normal molar relation, distal movement of maxillary first molars, and anterior movement of maxillary incisors (anchorage loss). The mean age in the MD 1 group was 11.4 years; in the MD 2 group, 14.6 years. Results: The amount of distal movement of the first molars was significantly greater (P &lt; .01) and the anchorage loss was significantly lower (P &lt; .01) in the group with no second molars erupted. The molar distalization time was also significantly shorter (P &lt; .001) in this group, and thus the movement rate was two times higher. Conclusions: It is more effective to distalize the first maxillary molars before the second molars have erupted.


2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Sung-Hwan Choi ◽  
Kyongmin Koh ◽  
Kee-Joon Lee ◽  
Chung-Ju Hwang ◽  
Jung-Yul Cha

Objective. The aim of this study was to evaluate the morphological characteristics of the palatal rugae in Korean subjects to determine whether the palatal rugae can be used as an appropriate reference area for three-dimensional digital model superimpositions. Materials and Methods. In total, 343 patients (110 men, 233 women; mean age, 25.6±8.2 years) who had a digital model taken at their initial visit were included, and the numbers and types of right and left palatal rugae were investigated according to the primary, secondary, and fragmentary rugae. Finally, the differences in the positions of the third primary ruga were investigated according to the presence of additional rugae posterior to the third primary ruga. Results. The number of primary palatal rugae ranged from one to six, with 43.5% of the subjects having three primary rugae and 36.1% having four primary rugae; there were no significant differences between sexes. Except for the fragment rugae, the numbers of primary and secondary rugae were not significantly different between the left and right sides. The third primary ruga was located more significantly anteriorly when there was an additional ruga posterior to the third primary ruga (P < 0.001). Conclusions. The numbers of the palatal rugae vary greatly among individuals, and this affects the anteroposterior position of the third primary ruga. When the third primary ruga is located anteriorly, care should be taken when using it as a reference area for superimposition with a digital model before and after orthodontic treatment.


2021 ◽  
Vol 11 (23) ◽  
pp. 11216
Author(s):  
Chiho Moon ◽  
George K. Sándor ◽  
Edward Chengchuan Ko ◽  
Yong-Deok Kim

Backgrond: Until now, there have been many studies on the postoperative stability of orthognathic patients treated with traditional fixed orthodontic appliances. Recently, the use of clear aligners as orthodontic appliances has increased in orthodontic treatment for aesthetic and patient convenience. The aim of this preliminary study was to investigate the stability and characteristics of patients undergoing orthognathic surgery using clear aligners. Patients and Methods: This study was performed on patients who underwent orthognathic surgery by one surgeon at Pusan National University Dental Hospital from April 2017 to August 2021. A comparative study was conducted on five patients treated with clear aligners during orthodontic treatment and ten patients treated with traditional fixed appliances as a control group. Postoperative skeletal changes and recurrence were evaluated by cone beam computed tomography and lateral cephalometric radiographs taken two days postoperatively and six months postoperatively. Several measurement variables were used to confirm the presence or absence of recurrence, preoperative and postoperative orthodontic treatment period, and the number of extracted teeth. Results: Postoperative stability for six months after surgery was not significantly different between the clear aligner group and the traditional fixed appliance group. The preoperative orthodontic treatment period was also shorter in the clear aligner group, and the number of extracted premolar teeth and impacted teeth were also fewer in the clear aligner group, but there was no significant difference. Conclusions: Orthodontic treatment using clear aligners continues to develop, and it is believed that there is no limit to what can be accomplished during orthodontic surgery accompanied by clear aligners.


2017 ◽  
Vol 4 (2) ◽  
pp. 235
Author(s):  
I Wayan Dirgeyasa

This research aims to find out the typical categories of answers to Yes/No questions most used by students at selected Public Senior High Schools in Medan, Indonesia. These schools were classified into top favorite, medium favorite and non-favorite schools. Through a stratified clustered random sampling technique, six schools were chosen consisting of two schools from each classification. A number of 40 students were chosen from three class X, three class XI and three class XII at each of the six chosen schools, making a total sample of 720 students with 360 sets of dialogue scripts. Data was collected through documentation-recording dialogues. The data was transcribed and analyzed by descriptive analysis. The results of the research showed that: 1) the categories of the students’ answers to the Yes/No questions were distributed variously in terms of the six models. However, the distribution of the answers was not proportionally equal amongst all the models, 2) the dominant distribution of the answers was the third model with the formula Yes/No+additional information such as confirming, supporting, etc., reaching 37% of the total answers, whilst the least common models were the sixth and fourth categories respectively, which had 1% and 3% of the answers respectively, and finally 3) there was no significant difference in the distribution of the students’ answers in terms of the class of school whether top favorite, medium favorite or non-favorite. In conclusion, the ways to answer Yes/No questions need to be developed amongst students by their teachers by teaching and learning using natural, real life-like situations and in contextual ways.


2021 ◽  
Author(s):  
Hong Su ◽  
Kaiyuan Xu ◽  
Bing Han ◽  
Gui Chen ◽  
Tianmin Xu

Abstract Background: Anchorage control is one of the key components in the treatment of extraction cases. However, why anchorage loss happens is still an unanswered question. The purpose of this study was to investigate the most important factors contributing to the anchorage loss of maxillary first molars in premolar extraction cases. Methods:The study enrolled 726 upper premolar extraction cases, including 214 male patients and 512 female patients, and the average age was 14 (range: 9-45 years old).Factors including physiological characteristics, treatment mechanics and cephalometric variables were collected and their influences on the angulation changes of maxillary first molars were analyzed. Results: The average angulation change of maxillary first molar after treatment was 2.81°, meaning the molar tipped forward during treatment by 2.81°. The change of UM/PP showed statistically significant difference in different sex ( male 3.84°±5.26 ° vs female 2.38°±5.10°), age (adult -0.05°±4.73 ° vs teenager 3.46°±5.07°), and molar relationship(Class II 3.28°±5.15°vs Class I 2.36°±5.19°). There are six variables accounted in the regression analysis (R=0.608, R²=37.0%). Among them, the pre-treatment molar tipping (Standardized Coefficients:-0.65) and the pre-treatment incisor/molar height ratio (Standardized Coefficients:-0.27)were the most important factors influencing anchorage loss during treatment.Conclusion: Compared with treatment-related factors, the patient’s physiological characteristics play a more important role in anchorage loss. The pre-treatment angulation of the maxillary first molar is the most contributing factor of the maxillary molar angulation changes, which are often predisposing anchorage loss.


2021 ◽  
Author(s):  
Hong Su ◽  
Kaiyuan Xu ◽  
Bing Han ◽  
Gui Chen ◽  
Tianmin Xu

Abstract Background: Anchorage control is one of the key components in the treatment of extraction cases. However, why anchorage loss happens is still an unanswered question. The purpose of this study was to investigate the most important factors contributing to the anchorage loss of maxillary first molars in premolar extraction cases. The study enrolled 726 upper premolar extraction cases, including 214 male patients and 512 female patients, and the average age was 14 (range: 9-45 years old).Factors including physiological characteristics, treatment mechanics and cephalometric variables were collected and their influences on the angulation changes of maxillary first molars were analyzed. Results: The average angulation change of maxillary first molar after treatment was 2.81°, meaning the molar tipped forward during treatment by 2.81°. The change of UM/PP showed statistically significant difference in different sex ( male 3.84°±5.26 ° vs female 2.38°±5.10°), age (adult -0.05°±4.73 ° vs teenager 3.46°±5.07°), and molar relationship(Class II 3.28°±5.15°vs Class I 2.36°±5.19°). There are six variables accounted in the regression analysis (R=0.608, R²=37.0%). Among them, the pre-treatment molar tipping (Standardized Coefficients:-0.65) and the pre-treatment incisor/molar height ratio (Standardized Coefficients:-0.27)were the most important factors influencing anchorage loss during treatment.Conclusion: Compared with treatment-related factors, the patient’s physiological characteristics play a more important role in anchorage loss. The pre-treatment angulation of the maxillary first molar is the most contributing factor of the maxillary molar angulation changes, which are often predisposing anchorage loss.


1975 ◽  
Vol 2 (1) ◽  
pp. 47-51 ◽  
Author(s):  
Elizabeth A. Pickering ◽  
Peter Vig

Search of the literature has failed to reveal any previous objective analysis of changes produced by treatment. Using the Occlusal Index a survey was carried out on study models of patients accepted for treatment in the Orthodontic Department of The London Hospital, over a nine year period (1963–71). The spread of severity of malocclusion of these patients was assessed to see if there had been a gradation in severity through the period as reflected by a trend in the yearly mean values of the Occlusal Index scores. Analysis of the results failed to show any discernible trend. The Occlusal Index was used to gain an objective and quantitative assessment of change produced by treatment and subsequently to correlate this change with the use of fixed and removable appliances. A slight but statistically significant difference was apparent in treatment results. Fixed appliance cases showed superiority to removable appliance cases, producing a better end result and greater degree of improvement. The difficulties in the use of application of the Occlusal Index to British cases are discussed and suggestions are made for modification.


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