Aims We evaluated the effect of chitosan gel on total oral bacteria, Porphyromonas gingivalis , Tannerella forsythia , and Treponema denticola , during orthodontic treatment with mini-implants. Material and methods Thirty subjects with 52 orthodontic mini-implants were divided into three groups: one group was treated with chitosan gel, the other group with chlorhexidine gel, and the control group with placebo. The plaque of the orthodontic peri -mini-implant area was collected before and after gel treatment. The total oral bacteria and red-complex bacteria of P. pingivalis , T. forsythia , and T. denticola were determined with reverse transcription-quantitative PCR. Results Thirty-four orthodontic mini-implants (65.38%) appeared as healthy and showed no clinical signs of inflammation. The total number of bacteria was reduced after chitosan gel application. The highest decrease in the proportion of P. gingivalis was observed in the chlorhexidine gel application group, which showed a value of 70.86%, whereas the chitosan gel application showed a reduction of only 26.59%, and the control gel application showed the lowest reduction effect of only 2.55%. The difference in the reduction between gel application groups was significant (P < 0.05) for T. denticola and T. forsythia . Conclusion The gel containing chitosan reduced the levels of total oral bacteria and red-complex bacteria.

ABSTRAKPendahuluan: Gigitan silang posterior didefinisikan sebagai relasi abnormal antara gigi molar dan/atau premolar rahang atas dan bawah dalam arah bukal-lingual pada oklusi sentrik. Diastema atau celah antar gigi merupakan kondisi yang umum ditemui dan menjadi salah satu masalah estetis dan maloklusi. Tujuan penulisan laporan kasus ini adalah menjelaskan perawatan ortodontik kasus maloklusi kelas III dengan multiple diastema dan gigitan silang unilateral. Laporan kasus: Pasien laki laki 25 tahun datang ke Klinik Spesialis Ortodontik Rumah Sakit Gigi dan Mulut Fakultas Kedokteran Gigi Universitas Indonesia dengan keluhan gigi depan berjarak. Pasien mendapat diagnosa maloklusi skeletal kelas III dengan multiple diastema pada gigi anterior rahang atas dan gigitan silang posterior unilateral. Kasus ini dikoreksi dengan ortodontik cekat tanpa pencabutan menggunakan braket preskripsi MBT slot 0,022. Perawatan secara garis besar meliputi pengaturan ruangan serta penggunaan criss-cross elastic di akhir perawatan untuk perbaikan gigitan silang unilateral. Perawatan ortodontik diselesaikan dalam waktu 18 bulan. Simpulan: Perawatan ortodontik cekat pada kasus maloklusi kelas III dengan ekspansi lengkung rahang disertai penggunaan criss- cross elastic yang teratur dapat mengoreksi gigitan silang. Recontouring gigi anterior rahang atas paska pengaturan ruang pada kasus multiple diastema juga memberikan tampilan senyum pasien yang lebih estetis.Kata kunci: multiple diastema; gigitan silang posterior; maloklusi kelas III ABSTRACTIntroduction: Posterior crossbite is an abnormal relationship between the maxillary and mandibular molars and premolars in the buccal-lingual direction in centric occlusion. Diastema or gap between teeth is a common condition and is one of the aesthetic problems and malocclusion. This case report aims to describe the orthodontic treatment of a class III malocclusion case with multiple diastema and unilateral crossbite. Case report: A 25-year-old male patient came to the Orthodontic Specialist Clinic of the Dental Hospital of the Faculty of Dentistry of the University of Indonesia with complaints of distant front teeth. The patient was diagnosed with skeletal class III malocclusion with multiple diastema of anterior maxillary teeth and unilateral posterior crossbite. This case was corrected with fixed orthodontics without extraction using a 0.022 slot MBT prescription bracket. Treatment generally includes room management and a criss-cross elastic at the end of the treatment to repair unilateral crossbites. The orthodontic treatment was completed within 18 months. Conclusion: Fixed orthodontic treatment in cases of class III malocclusion with the expansion of the jaw arch with regular use of criss-cross elastic can correct the crossbite. Recontouring of anterior maxillary teeth after spatial adjustment in cases of multiple diastema also gives the patient a more aesthetic smile.Keywords: multiple diastema; posterior crossbite; class III malocclusion