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"ABSTRAK Tindakan intrusi molar pertama rahang atas menggunakan penjangkar miniscrew yang diletakkan di sisi bukal dan palatal sering digunakan dan memiliki tingkat keberhasilan yang cukup tinggi. Penelitian ini dilakukan untuk mengetahui perbedaan distribusi tekanan pada tindakan intrusi molar pertama rahang atas menggunakan miniscrew yang diletakkan dengan ketinggian 3 mm, 5 mm, dan 7 mm dari cementoenamel junction, serta sudut 45° dan 90° dari sumbu gigi. Model tiga dimensi struktur kraniomaksila dibuat dari hasil pemindaian tengkorak kering. Terdapat empat Region of Interest (ROI) yang ditentukan yaitu akar molar pertama rahang atas, alveolar molar pertama rahang atas, miniscrew, dan alveolar miniscrew. Terdapat perbedaan bermakna (p<0,05) distribusi tekanan pada tindakan intrusi molar pertama rahang atas, baik pada kelompok ketinggian maupun sudut pemasangan miniscrew, di semua ROI. Gambaran tekanan pada molar pertama rahang atas dan alveolarnya terkonsentrasi di daerah akar palatal dan trifurkasi. Gambaran tekanan pada alveolar miniscrew menunjukkan perbedaan distribusi spektrum warna pada kelompok sudut pemasangan. Tindakan intrusi molar pertama rahang atas dipengaruhi oleh ketinggian dan sudut pemasangan miniscrew.

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ABSTRACT

Miniscrew-assisted upper first molar intrusion had been developed recently with high rate of success. The placement of two miniscrews, buccally and palatally, is usually done to deliver such force. This research was conducted to analyse the difference of stress distribution of upper first molar intrusion using two miniscrews, placed at 3 mm, 5 mm, and 7 mm from cementoenamel junction, and 45° and 90° from the tooth axis. A three-dimensional solid model of craniomaxillary structure was rendered and the region of interests (ROI) were defined at the first molar roots, its alveolar, miniscrews, and the bone surrounding the miniscrews. Statistical analysis showed that there were significant differences (p<.05) of Von Mises mean values in the ROIs between all groups of height and angle of placement. Visual analysis showed that the stress distribution in first molar roots were concentrated at the trifurcation and palatal root apex area, while in the bone surrounding the miniscrews, the highest stress distribution was located diversely among separate angles of placement groups. The stress distribution of upper first molar intrusion using miniscrews anchorage was affected by heights and angles of miniscrews placement.

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"ABSTRAKLatar belakang: transpalatal arch masih banyak digunakan pada perawatanortodonti dengan pencabutan premolar sebagai reinforced, untuk mencegahkehilangan penjangkaran. Dampak tekanan ortodonti pada jaringan periodontaldengan dan tanpa TPA dapat diketahui dengan mengetahui besar distribusi stresspada jaringan periodontal. Besar distribusi stress pada jaringan periodontal gigimolar satu dan dua secara in vivo tidak mungkin dilakukan. Maka dilakukanmelalui simulasi tiga dimensi 3D dengan Finite Element Analysis FEA .Tujuan: untuk melihat perbedaan distribusi stress minPS, maxPS dan vonMS pada gigi molar satu atas dengan TPA, TPA dan melibatkan gigi molar dua dantanpa TPA jika diberikan gaya distalisasi kaninus dengan daya sebesar 150g.Metode: Penelitian ini merupakan suatu penelitian eksperimental laboratorikdengan membuat model tengkorak secara tiga dimensi yang terdiri dari model gigimolar pertama atas dan tulang alveolar pendukungnya pada model maksila 3Ddengan TPA, dengan TPA dan melibatkan gigi molar dua dan tanpa TPA,kemudian dilakukan simulasi distalisasi kaninus dengan gaya 150g dengan FEA.Hasil: Ada perbedaan besar distribusi stress yang bermakna pada model 1 TPA ,model 2 TPA M2 dan model 3 tanpa TPA pada gigi molar satu atas dan tulangaveloar sekitar gigi molar satu atas p 0,000 ; p< 0,05 Kesimpulan: Nilai distribusi stress minPS, maxPS dan vonMS tertinggi padamodel tanpa TPA, kemudian nilainya menurun pada model TPA dan model TPAyang menyertakan gigi molar dua, baik pada gigi maupun tulang alveolar.

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Background:

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ABSTRACTThe transpalatal arch is used as a reinforced anchorage onextraction case to prevent anchorage loss. It is impossible to measure humanperiodontal stress distribution, so an alternative approach with three dimensionsimulation using Finite Element Analysis FEA .Aim: This study aimed to compare stress distribution on upper first molar dan itsalveolar bone with TPA, with TPA and upper second molar and without TPAwhen 150g force was applied during canine movement.Methods: This experimental laboratory was done with the contruction of the 3Dmodel that consist of 3D model of maksila with TPA, with TPA and upper secondmolar and without TPA. Canine distalization simulation was done with 150 gramdistalization force.Result: The result showed that stress distribution on 1st model 1 TPA , 2ndmodel 2 TPA M2 and 3rd model 3 without TPA was significantly higher onthe upper first molar and its alveolar bone.Conclusion: The highest stress distribution minPS, maxPS dan vonMS is on themodel without TPA and the number decrease on a model with TPA and modelTPA with the upper second molar."

"We conducted a finite element simulation by using a computer program, ATENA, to verify the behavior of T-section reinforced concrete beams strengthened by bonded wire ropes in the negative moment region with a pretensioned initial prestressing force; we compared this behavior with that in experimental tests. The simulation was performed on five models consisting of one unstrengthened beam and beams strengthened by wire ropes with initial prestressing forces of 0%, 10%, 20%, and 30%. We found that the capacity of a flexural load had the ratios to the experimental results close to 1 — that is, 1.25, 1.16, 1.12, 1.01, and 1.10, for UB, SB1, SB2, SB3, and SB4, respectively. The ratios of effective stiffness, as the result of the simulation, to the experimental results were 1.45, 1.08, 1.76, 2.13, and 2.46 for UB, SB1, SB2, SB3, and SB4, respectively. We also observed that crack propagation developed in the finite element simulation indicated that all models underwent flexural failure."