Cephalometric and digital model analysis of dentoskeletal effects of infrazygomatic miniscrew vs. Essix- anchored Carriere Motion appliance for distalization of maxillary buccal segment: a randomized clinical trial.

TRIAL DESIGN: Parallel. OBJECTIVE: To compare skeletally anchored Carriere Motion appliance (CMA) for distalization of the maxillary buccal segment vs. Essix anchored CMA. METHODS: Thirty-two class II malocclusion patients were randomly allocated into two equal groups. One group was treated with infrazygomatic (IZC) miniscrew- anchored CMA (IZCG) and the other group treated with Essix retainer- anchored CMA (EXG). Two lateral cephalograms and two digital models for upper and lower arches were taken for each patient: immediately before intervention and after distalization had been completed. RESULTS: Distalization period was not significantly different between the two groups. In contrast to EXG, IZCG showed insignificant difference in ANB, lower incisor proclination, and mesial movement of the lower first molar. There was significant rotation with distal movement of maxillary canine and first molar in both groups. CONCLUSION: IZC anchored CMA could eliminate the side effects of class II elastics regarding lower incisor proclination, mesial movement lower molars with a more significant amount of distalization of the maxillary buccal segment but with significant molar rotation. TRIAL REGISTRATION: The ClinicalTrials.gov Protocol Registration and Results System (PRS) has this RCT registered as (NCT05499221) on 12/08/2022.

Dentofacial effects of miniscrew-anchored maxillary protraction on prepubertal children with maxillary deficiency: a randomized controlled trial.

BACKGROUND: The introduction of bone-anchored maxillary protraction eliminated the side effects of facemask in the early treatment of patients with maxillary retrusion. This study aimed to evaluate the effects of miniscrew-anchored maxillary protraction (MAMP) and compare them with the growth changes in an untreated control group in growing patients with Class III malocclusion. METHODS: Forty growing patients with Class III malocclusion and retrognathic maxilla were randomly allocated into two groups: treated and control groups. In the treated group, patients were treated with full-time intermaxillary Class III elastics (C3E) anchored by a hybrid hyrax (HH) in the maxilla and a bone-supported bar in the mandible. Protraction was stopped after obtaining a positive overjet. Cephalometric radiographs were acquired before and after the treatment. Data were statistically analyzed on an intention-to-treat basis. Intergroup comparisons were also made using analysis of covariance with the readings at T0 as a covariate. RESULTS: Forty patients agreed to participate, and 30 of them completed the study (treated group, n = 17; control group, n = 13). The average treatment duration was 11.9 months. MAMP resulted in a significant maxillary advancement (A-VR, 4.34 mm) with significant control over the mandibular growth. No significant increase in the mandibular plane angle was found in the treated group compared with the control group. The upper and lower incisors showed significant protrusion in the treated group. CONCLUSIONS: Within the limitations of this study and high attrition rate, the MAMP protocol can effectively increase maxillary forward growth with good control over the growth of the mandible antero-posteriorly and vertically.

Rate of upper incisor retraction in Class II division 1 patients managed with palatal versus buccal miniscrew supported segmental orthodontics: Randomized parallel clinical trial.

OBJECTIVE: This study was conducted to compare maxillary incisor retraction rates using buccal orthodontics with segmented arch approach supported by a buccal or palatal mini-screw in non-growing Class II Division 1 patients during a 3-month period. PATIENTS AND METHODS: All patients between September 2018 and December 2021 with following criteria were included: non-growing class II division 1 protrusion, indication for premolar extraction, no or little crowding, normal overbite, no previous orthodontic treatment, no systematic disease, good oral hygiene, no periodontal problems or oral habits. Mini-implant was inserted buccally or palatally between upper second premolar and first molar bilaterally. Incisor retraction was manipulated by a 200-gram force through a nickel-titanium closed-coil spring extended from the mini-implant to the segmental design. Study casts were made before retraction and after every 4 weeks (T0: baseline, T1: 4 weeks, T2, 8 weeks, T3: 12 weeks). A repeated measures ANOVA was performed for total comparison of data (mm of retraction) on 3D casts. A pairwise t test with Bonferroni correction was used for comparison between two experimental periods for the same group. An independent samples t-test was also used for comparison between two groups for the same experimental period. RESULTS: Of 30 patients meeting the eligibility criteria, only 28 were included with mean age 16±2.5 years. Repeated measures ANOVA revealed significant differences in incisor retraction between the time intervals for both buccal and palatal groups (P=0.001). In addition, the paired-sample t test indicated a significant difference between each time interval for both the buccal and palatal groups (P=0.001), except between T3 and T2 for the palatal group (P=0.09). The independent sample t-test revealed significant differences between the buccal and palatal groups at T1 (Mean: 0.55 [0.355-0.748],=0.001) and T2 (Mean: 1.4 [0.91-1.88], P=0.001); whereas no significant difference was found at T3 (Mean: 1.15 [0.67-1.63], P=0.945). CONCLUSIONS: Anterior retraction using a segmental palatal model with mini-screws was effective regardless of the buccal or palatal situation of the minivis. Retraction of incisors with palatal miniscrews was significantly faster in the first two months.

In vitro testing of shear bond strength of orthodontic brackets bonded to different novel CAD/CAM ceramics.

Background. The present study aimed to evaluate the bond strength of metal bracket (MB) and ceramic bracket (CB) bonded to different CAD/CAM ceramic substrates etched with hydrofluoric acid (HFA) vs. phosphoric acid (PA). Methods. A total of 120 CAD/CAM ceramic blocks in 12 groups were fabricated from three different CAD/CAM ceramic materials: VITABLOCS Mark II, VITAENAMIC, and IPS e.max CAD. Each ceramic material group was divided into two etching groups: one treated with 9.5% HFA and the other treated with 37%. Sixty metal and CBs of the upper right central incisor were bonded to the HFA-treated blocks. Another 60 metal and CBs were bonded to the PA treated blocks. All the bonded specimens were thermocycled before shear bond strength (SBS) testing. Then the bond failure mode was recorded Results. There were no significant differences in SBS values between the three CAD/CAM ceramic materials. The HFA-treated specimens exhibited significantly higher SBS values than the PA-treated specimens. Also, the SBS values of CBs were significantly higher than the metal brackets (MBs). The adhesive remnant index (ARI) score was 4 for most of the groups, indicating that almost no adhesive remained on the porcelain surface. Conclusion. The CAD/CAM ceramic type did not influence SBS; however, HFA exhibited significantly higher SBS compared to PA.

Dento-skeletal effects of the Pendulum Hygienic Distalizer.

OBJECTIVES: To evaluate dento-skeletal effects of the Pendulum Hygienic Distalizer (P.H.D), utilized on expansion of the maxillary arch and distalizing of maxillary first molars. MATERIAL AND METHODS: Ten patients were selected from the outpatient clinic of Department of Orthodontics, Faculty of Dentistry, Mansoura University having: (1) Skeletal Class I with moderate maxillary crowding; (2) Angle Class II molars relation; (3) Constricted maxillary arch (posterior crossbite); (4) Ages ranged from 11 to 14 years with an average age of 12 years and 2 months. The changes that, brought by the appliance were evaluated from the lateral cephalometric, postero-anterior radiographs and study cast model taken before and after appliance application by means of a paired t-test. RESULTS: Significant amounts of maxillary expansion, molar distalization, molar distal tipping and anchorage loss were observed. The amount of maxillary expansion was 4.35 ± 072 mm. The mean maxillary first molar distal movement was 2.27 ± 0.52 mm with a distal tipping of 1.71 ± 0.74 degrees in 3.19 ± 0.53 months. The rate ofdistal movement was 0.70 mm per month. Reciprocal mesial movement of the first premolars was 1.73 ± 0.92 mm with a mesial tipping of 2.60 ± 1.02 degrees. Maxillary incisors moved 1.80 ± 0.85 mm and tipped 2.02 ± 1.43 degrees mesially. CONCLUSIONS: It was concluded that the Pendulum Hygienic Distalizer works well with the treatment philosophy of Class II malocclusion with posterior cross-bite by expansion the maxillary arch and distalizing of maxillary molars.

Improving heating uniformity of pathological tissue specimens inside a domestic microwave oven.

A 3D coupled electromagnetic thermal model was developed using COMSOL 4.0 to predict the electromagnetic field distribution and temperature profile in pathological tissue samples immersed in a reagent inside the oven cavity. The effect of the volume of reagent on the mean heating rate and heating uniformity within the tissue sample was investigated. Also, the effect of using a water load, as a method of temperature control, is emphasized. A well insulated K type thermocouple connected to a PC is used for model validation. Good agreement is found between experimental and simulated temperature profiles. Results show that as the volume of reagent increases, the mean heating rate decreases and temperature homogeneity increases. Also, it is possible to minimize overshooting temperature values inside the tissue sample and enhance tissue uniformity by about 27% using 100 ml of water load and 42.26% using 150 ml. Domestic microwave oven is a low cost economical tool that can speed up tissue processing steps. Achieving uniform heating inside the microwave oven is the key factor for improving workflow inside pathological labs and maintaining tissue quality and integrity.

Treatment of developing Class II Division 1 malocclusion with Jumper Twin Block.

UNLABELLED: The objective of this study was to determine dental and skeletal effects of the jumper twin block appliance in the treatment of developing Class II, Division I malocclusion. METHODS: 15 girls aged 9 to 11 years old with class II division 1 and samephysical maturation status were included in the study over one year. Cephalometric data and study models were analyzed statistically with Paired t-test. RESULTS: The jumper twin block had skeletal and dental effects. Stimulation of forward mandibular growth, backward displacement of the maxilla, significant increase in the anterior and posterior facial height, retroclination of the upper incisors, proclination of the lower incisors and significant improvement of the overjet and overbite had been found. CONCLUSIONS: The jumper twin block appliance with gradual bite advancement was effective in treatment of developing Class II division 1 malocclusion.

Accuracy and reliability of cone-beam computed tomography measurements: Influence of head orientation.

INTRODUCTION: The purpose of this research is to determine the accuracy and reliability of measurements obtained from 3-dimensional (3D) cone-beam computed tomography (CBCT) for different head orientations. METHODS: Stainless steel wires were fixed to a dry skull at different places. The skull was scanned by using CBCT in the centered and 5 other positions. Intraobserver and interobserver reliability tests were performed by using 6 landmarks identified on the virtual 3D skulls by 2 operators. Two methods were used to determine the accuracy of measurements on the virtual 3D skull scanned in different positions. In the first method, 12 linear distances were compared on the physical skull and the 3D virtual skull in the centered and the other scanning positions. In the second method, registration of each of the 5 positions on the centered position was done separately, and coordinates of 11 landmarks were identified in each position and compared with the centered position. Data gathered from the 2 methods were compared statistically. RESULTS: Concordance correlation and Pearson correlation coefficients values were almost 0.9999 in all the comparisons denoting: (1) high intraobserver and interobserver reliability; (2) very high concordance between the physical skull and the CBCT centered-position measurements; (3) very high concordance between measurements of the centered position in relation to those obtained from the different skull positions; and (4) registration of the skulls in the different positions showed high concordance, with the highest values between the centered and off-centered positions, and the lowest with the complex position. CONCLUSIONS: Accuracy and reliability of CBCT measurements are not affected by changing the skull orientation. Thus, the upper-lip and chin rests should not be considered absolute requirements during CBCT imaging if a stable head position is ensured.

Three dimensional approach for realistic simulation of facial soft tissue response: a pilot study.

Facial attractiveness is ranked as a principal priority among patients seeking orthodontic treatment or combined surgical orthodontic therapy. A successful treatment planning process necessitates an accurate prediction of the postoperative facial profile. In this manuscript, the simulation procedure on a real clinical case using virtual volumetric 3D mesh through different scenarios of orthognathic procedures was done. Results depict several facial soft tissue outcomes, with the likelihood of sharing with the patient the most esthetically pleasing end result prior to carrying out the surgical procedure.

Three-dimensional dental measurements: An alternative to plaster models.

INTRODUCTION: The aim of this study was to compare the accuracy of dental measurements taken with calipers on plaster dental casts and those from computed tomography scans of the dentition with a dental measurement program. METHODS: The sample consisted of plaster dental models of 34 orthodontic subjects. Dental arch measurements, including mesiodistal widths of teeth, arch widths, arch lengths, arch perimeters, and palatal depths were made with the calipers. The patients were also scanned with computed tomography, and measurements were made digitally with a 3-dimensional-based dental measurements program (3DD, Biodent, Cairo, Egypt). RESULTS: The results showed strong agreement in most measurements between the conventional method and the 3DD in the 3 planes of space. The mesiodistal measurements of the maxillary right and left second premolars, left central incisor, and right first molar, and the mandibular left and right central incisors, right canine, and left first premolar had fair agreement. CONCLUSIONS: Excellent agreement between the measurements with the conventional and 3DD methods in the 3 planes of space was found; 3DD can be an alternative to conventional stone dental models.

Methods for managing 3-dimensional volumes.

The introduction of 3-dimensional (3D) volumetric technology and the massive amount of information that can be obtained from it compels the introduction of new methods and new technology for orthodontic diagnosis and treatment planning. In this article, methods and tools are introduced for managing 3D images of orthodontic patients. These tools enable the creation of a virtual model and automatic localization of landmarks on the 3D volumes. They allow the user to isolate a targeted region such as the mandible or the maxilla, manipulate it, and then reattach it to the 3D model. For an integrated protocol, these procedures are followed by registration of the 3D volumes to evaluate the amount of work accomplished. This paves the way for the prospective treatment analysis approach, analysis of the end result, subtraction analysis, and treatment analysis.

Evaluating the effect of Sabbagh Universal Spring during treatment of growing class II malocclusions.

Angle Class II division 1 malocclusion has been one of the most encountered problems in the orthodontic practice. In growing patients, mandibular repositioning appliances are the method of choice to induce mandibular growth and are termed functional appliances. This study was carried out to investigate the possible effect of the Sabbagh Universal Spring2 (SUS2) on the dental and skeletal cephalometric measurements in the permanent dentition of ten growing patients with Class II division 1 malocclusion and to compare its effect with the similar available data of similar fixed functional appliances. It was concluded that the Sabbagh Universal Spring2 appliance works well with the treatment philosophy of Class II division 1 malocclusion with retruded mandible by advancing the mandible anteriorly.