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Histomorphometrical and radiological comparison of low-level laser therapy effects on distraction osteogenesis: experimental study

Distraction osteogenesis (DO) is the application of traction to the callus formed between bone segments and stimulation of bone formation by creating stress on the callus with this traction. Shorten the duration of DO and increasing the capacity of bone formation is important to prevent the possible complications of DO. For this reason, it was considered that low-level laser therapy (LLLT) may affect positively DO and it can decrease the complication range by shortening the period. Unilateral mandibular distractors were applied on 16 female white New Zealand rabbit to prove this hypothesis with micro CT, plain radiograph and histomorphometric analyses. Eight rabbits were applied LLLT with GaAlAs laser on the distraction area during the distraction period. On the post-distraction 28th day, four rabbits from study group and four rabbits from control groups were sacrificed. The rest of the rabbits were sacrificed on post-distraction 56th day. As a result of this study, significant positive effects of LLLT on post-distraction 28th day were revealed with all analyses. In histomorphometrical analyses, new bone formation was significantly higher in short-term laser applied group comparing to that of short-term control group (p = 0.029). In both microCT and plain radiograph, the highest radioopacity values were observed in short-term laser group when compared with that of the controls (p = 0.043 and p = 0.025, respectively). Even though LLLT increased the healing capacity on short-term, it was not sufficient on long-term (post-distraction 56th day) healing. LLLT application on distraction period, activate healing on bone so it may decrease DO period. The result of this study should be supported with clinical studies and the most effective laser source, dose and application time should be revealed with experimental and clinical studies.

Evaluation of prebent miniplates in fixation of Le Fort I advancement osteotomy with the finite element method.

The stability of segments after Le Fort I osteotomy first attracted the researchers interest when the surgical concept was conceived. Prebent plates are the ultimate modification of plate systems in craniofacial surgery; they have two right angles and are available in different lengths for use in maxillary advancement surgery. For this research, cone-beam computed tomography (CBCT) images of a male patient were obtained and scanned, and a 3D maxillary bone was created. Conventional Le Fort I osteotomies with 5 and 10 mm advancements were performed on both the cortical and trabecular bone using the Surgical Simulation Module of Mimics software; 1.7 mm Leibinger standard orthognathic 5-hole L plates and 1.7 mm Leibinger orthognathic advancement 11-hole prebent plates were adapted to the fragments. Displacement of the segment, the von Mises (VM) stresses (on the titanium miniplates) and the maximum principal (MP) stresses (on the bone) were evaluated for each configuration. Prebent plates offer a good alternative to the conventional two plate system, except in operations where maxillary advancement exceeds 5 mm. Surgical procedures that include advancement exceeding 5 mm or vertical position changes remain controversial and further studies are needed.

Effects of inter-implant distance and implant length on the response to frontal traumatic force of two anterior implants in an atrophic mandible: three-dimensional finite element analysis

The aim of this three-dimensional finite element analysis study was to examine the biomechanical behaviour of dental implants and the surrounding bone under traumatic frontal force. Models were created of an edentulous atrophic mandible using cone beam computed tomography data from a patient; two titanium alloy implants (Ti-6Al-4V) were virtually inserted into the anterior of the mandible. Six different variations were modelled to represent differences in implant location (lateral incisor vs. canine placement) and implant length (monocortical, bicortical, and long-bicortical). A static force of 10 MPa was applied frontally to the symphysis region of each model, and the maximum equivalent von Mises strain of bone, maximum von Mises stress of implants, and chromatic force distributions in bone and implants were recorded. In general, when compared to lateral incisor placement, canine placement of implants resulted in greater von Mises stress on implants and greater equivalent von Mises strain on bone. The findings of the present study showed the distribution of traumatic force to be affected more by inter-implant distance than by implant length. The insertion of implants in the lateral incisor area was found to be a better solution than canine area placement in terms of frontal plane trauma and fracture risk.

Gene-Expression Profiles in Generalized Aggressive Periodontitis: A Gene Network-Based Microarray Analysis

BACKGROUND In this study, molecular biomarkers that play a role in the development of generalized aggressive periodontitis (GAgP) are investigated using gingival tissue samples through omics-based whole-genome transcriptomics while using healthy individuals as background controls. METHODS Gingival tissue biopsies from 23 patients with GAgP and 25 healthy individuals were analyzed using gene-expression microarrays with network and pathway analyses to identify gene-expression patterns. To substantiate the results of the microarray studies, real-time quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was performed to assess the messenger RNA (mRNA) expression of MZB1 and DSC1. The microarrays and qRT-PCR resulted in similar gene-expression changes, confirming the reliability of the microarray results at the mRNA level. RESULTS As a result of the gene-expression microarray studies, four significant gene networks were identified. The most upregulated genes were found as MZB1, TNFRSF17, PNOC, FCRL5, LAX1, BMS1P20, IGLL5, MMP7, SPAG4, and MEI1; the most downregulated genes were found as LOR, LAMB4, AADACL2, MAPT, ARG1, NPR3, AADAC, DSC1, LRRC4, and CHP2. CONCLUSIONS Functions of the identified genes that were involved in gene networks were cellular development, cell growth and proliferation, cellular movement, cell-cell signaling and interaction, humoral immune response, protein synthesis, cell death and survival, cell population and organization, organismal injury and abnormalities, molecular transport, and small-molecule biochemistry. The data suggest new networks that have important functions as humoral immune response and organismal injury/abnormalities. Future analyses may facilitate proteomic profiling analyses to identify gene-expression patterns related to clinical outcome.

Immediate Reconstruction Using Autogenous Bone Graft in Huge CompoundOdontoma

Odontoma is placed into the odontogenic tumor classifications. But it is known as a hamartomatous lesion or a developmental abnormality rather than a odontogenic tumour. It is subclassified into 2 types: (a) compound odontoma: consisting of many little teeth like structures (denticles) (b) complex odontoma: the feature is not like a tooth but it is made of dental tissues in irregular amounts. In this paper, we present two different compound odontoma cases treated by a similar technique using “Autogenous Bone Cover”. Very large odontomas were enucleated and surgical side was covered with autogenous bones. After that, autogenous bones were fixed by reconstruction plates and mini titan screws, in order to avoid a possible fracture. After one year of follow up period, healings of the patients were uneventful.

Travma sonucu oluşan anterior tek diş eksikliklerinin implant destekli sabit restorasyonlar ile tedavisi: 2 olgu sunumu

Dentoalveolar travmalar genc bireylerde ve ozellikle maksiller anterior bolgede siklikla karsilasilan olgulardandir. Bu travmalar sonucu olusan tek dis eksikliklerinde hastalarin yuksek estetik beklentilerini karsilamak icin uygun materyal secimi ve detayli bir planlama buyuk onem arz etmektedir. Bu olgu sunumunun amaci dentoalveolar travma sonucu maksiller santral disini kaybetmis 2 genc erkek hastanin implant destekli, kisiye ozel uretilmis zirkonya abutmentlar uzerine uygulanan zirkonya altyapili tam seramik tek kronlar ile tedavisini sunmaktir. 23 ve 18 yasinda iki genc erkek hasta gecirdikleri dental travma sebebi ile maksiller santral dislerini kaybetmistir. Her iki hastaya birer adet kemik seviyesi implant yerlestirildi ve iyilesme sonrasi yumusak doku sekillendirmesi yapildi. Kisiye ozel olarak uretilen zirkonya abutmentlardan destek alan zirkonya altyapili tam seramik restorasyonlar hastalara teslim edildi. Hastalarin estetik ve fonksiyonel beklentileri karsilandi. 1 yillik takip sonunda herhangi bir komplikasyonla karsilasilmadi.

Bifosfanat kullanimina bağli çenelerde gelişen osteonekrozlar: Çok merkezli retrospektif çalişma

Bifosfonatlar (BP), metastatik kemik hastaliklari ve osteoporoz tedavisinde kullanilan kemik rezorbsiyonu inhibitorleridir. Bifosfanat kullanimina bagli cenelerde gelisen osteonekroz (BBCO), cenelerinde radyasyon tedavisi gormemis, bifosfanat kullanan ya da kullanmis hastalarda mandibula ya da maksillada 8 haftadan daha uzun suren kemik ekspozu ile karakterize bir durum olarak tanimlanmistir. Bu calismada farkli merkeze yonlendirilen BBCO vakalari retrospektif olarak sunulmustur. 2012 ve 2013 yillarinda GATA Haydarpasa Egitim Hastanesi Dis Hekimligi, Kocaeli Universitesi Dis Hekimligi Fakultesi, ve Kirikkale Universitesi Dis Hekimligi Fakultesi, Agiz, Dis ve Cene Cerrahisi kliniklerine basvuran BBCO tanisi konulmus 18 hastanin demografik ozellikleri, anamnez bulgulari, klinik muayene bulgulari, bifosfanat cesidi ve kullanim bilgileri (sure, uygulama yolu) ve eger varsa ilgili sebep acisindan degerlendirmeleri yapilmistir. Hastalarin 12’ sinde mandibula (% 67), 5’ inde maksilla (%28) ve 1 hastada ise hem mandibula hem maksillada (%5) BBCO izlendi. Hastalarin 2 tanesi osteoporozis (% 11) nedeniyle 16 hasta ise (% 89) onkolojik tedavi nedeniyle bifosfanat grubu ilac kullanmaktaydi. Tip ve dis hekimligini ortak olarak ilgilendiren konu olmasi itibariyle bifosfanat grubu ilac tedavisine baslanacak hasta gruplarinin ortak klinikler tesis edilerek takip edilmeleri ve bilgi paylasimlariyla ortaya cikabilecek olasi komplikasyonlarin azaltilabilecegini dusunmekteyiz.