Craniomaxillofacial Changes Using High-Pull J-Hook Headgear and Mini-Implant Anchorage in Adolescents: A Structural Superimposition Method

Objective: The aim of this study was to compare the craniomaxillofacial changes when using high-pull J-hook headgear (HPJH) and mini-implants (MIs) as maxillary anchorage in adolescents. Study Design: 40 female adolescents with dentoalvolar protrusion were divided into 2 groups; the HPJH group (n=20) and the MI group (n=20). Lateral cephalograms taken before treatment (T0) and after anterior tooth retraction (T1) were superimposed on the stable structures and then craniomaxillofacial changes were evaluated. Results: The cranial base angle, SNB, and facial angle decreased in the HPJH group but increased in the MI group. ANB decreased more in the MI group than in the HPJH group. Mandibular plane angle increased in the HPJH group but decreased in the MI group. Facial height index increased in the MI group while it showed no change in the HPJH group. Mandibular true rotation occurred clockwise in the HPJH group and counterclockwise in the MI group. Maxillary central incisors were intruded and retracted more in the MI group than in the HPJH group. Maxillary first molars were extruded in the HPJH group and were intruded in the MI group. Maxillary first molars were protracted more in the HPJH group than in the MI group. Mandibular central incisors were retracted more in the HPJH group than the MI group. Mandibular first molars were extruded more in the MI group than in the HPJH group. Conclusion: More favorable craniomaxillofacial changes occurred in the MI group than in the HPJH group.

Improved control over implant anchorage under the use of the femoral neck system for fixation of femoral neck fractures: a technical note

Background The depth of bolt in Femoral neck system (FNS, DePuy Synthes, Oberdorf, Switzerland) is difficult to finely control as the length of the bolt is in units of 5 mm. Thus, this study introduces a method to control the depth of FNS bolt in analogue scale in patients with femoral neck fracture. Methods By the technique of control of reaming and retraction of bolt, the tip of implant could be positioned close to subchondral bone without harming it. The position of implant tip in four cases in which the introduced technique was applied was compared to that of eight cases where the standard technique was performed. Results The average tip-apex distance measured in the cases that underwent surgery using the suggested technique in this study was statistically significantly shorter than that measured in the cases that underwent surgery under manufacturer guidelines. Conclusion Even though the bolt of FNS is manufactured in the unit of 5 mm, the technique proposed in this study helps surgeons to adjust the depth of bolt for the fixation of femoral neck fracture using FNS.

Application of Microscrew Implant Anchorage in Orthodontics

Objective: To study the value of microscrew implant anchorage in orthodontic treatment. Methods: A total of 80 cases received orthodontic treatment in recent two years were selected and divided into experimental group and control group based on their received orthodontic measures, each group contains 40 cases. The control group was treated with general orthodontic treatment plan, while the study group received microscrew implant anchorage for the treatment. The clinical conditions of the two groups were counted and observed. Results: After different treatments, the effect of the study group was significantly better than that of the control group. All the indicators (including the improvement of molar displacement, incisor inclination angle and incisor convex distance) were available. In addition, there are obvious differences between the two groups in the occurrence of adverse reactions including inflammatory reaction, soft tissue edema and discomfort. Conclusion: In oral clinic, microscrew implant anchorage can achieve ideal curative effect for those who need orthodontics. Besides, its safety is relatively high, which is worth popularizing widely.

Evaluation of Angular Changes of Canine in En Masse Retraction of Maxillary Anterior Teeth Using Power Arm and Titanium Mini-Implant - A Split Mouth Randomised Control Study

BACKGROUND This study was conducted to determine angular changes of maxillary canine in en masse retraction of anterior teeth in a new modified power arm with a conventional intraoral anchorage unit compared to a mini-implant anchorage in the first premolar extraction case. We wanted to compare angular changes of maxillary canine between modified conventional anchorage with a power arm and titanium mini-implant anchorage in en masse retraction. METHODS A total of 15 participants requiring maxillary first premolar extraction was selected for this study. In each participant, the en mass retraction was carried out with miniimplants on one side & modified conventional anchorage with a power arm on the other side. The choice of mode of retraction on the right and the left side was done based on the coin flip method. Angular position of the maxillary canine was evaluated on orthopantomogram (OPG) & diagnostic cast. RESULTS A mean disto-palatal rotation observed post retraction was of 9° on the conventional anchorage side & 9.86° on the mini-implant anchorage side. A mean difference in maxillary canine angulations post retraction was 1.13° on the conventional anchorage side and 0.93° on the mini-implant side. An increase in angle suggested the tipping of canine teeth. The difference was very small which was not statistically & clinically significant. CONCLUSIONS There was no difference in the type of tooth movement during retraction by miniimplant and power arm suggesting minimal variation in teeth movement in the anterior region. So, the choice mainly depends on the type of the anchorage required in the given clinical situation. KEY WORDS Anchorage, Mini-Implant, Power Arm, Type of Tooth Movement

Evaluation of factors related to the success of miniscrew-assisted rapid palatal expansion

ABSTRACT Objectives To evaluate whether the success of miniscrew-assisted rapid palatal expansion (MARPE), performed in patients with advanced bone maturation is related to factors such as midpalatal suture (MPS) maturation, age, sex, or bicortical mini-implant anchorage. Materials and Methods Twenty-eight cone beam computed tomography (CBCT) scans of adults and post-pubertal adolescents treated by MARPE were included in the sample. CBCT images before (T0) and after expansion (T1) were used to evaluate the skeletal changes and the success or failure of MARPE. Axial images of MPS were extracted from T0 and classified into one of the five maturation stages. The correlation between MARPE success and the factors of age, sex, MPS maturation, and bicortical mini-implant anchorage was investigated. Results Only the age showed a statistically significant negative correlation with MARPE success and all the skeletal measures. There was an 83.3% success rate among individuals aged 15 to 19 years, 81.8% from 20 to 29 years, and 20% from 30 to 37 years. MPS maturation showed a negative correlation with the expansion effect. Subjects with stages B or C of MPS maturation showed a 100% success rate, followed by stage D (62.5%) and stage E (58.3%). Conclusions As age increased, there was a decrease in MARPE success and the skeletal effects of maxillary expansion. Sex and bicortical mini-implant anchorage were not shown to be relevant factors. There was no correlation between MPS maturation and MARPE success; however, it was observed that all cases of MARPE failure were classified as stage D or E of MPS maturation.