Autotransplantation of premolars and space closure in a patient with inflamed sinuses.

Congenital absence of permanent teeth can be treated by means of dental implants and prosthetics. Tooth autotransplantation is an alternative in growing patients because continued eruption of the transplanted tooth and associated alveolar bone growth can be expected. This clinical report presents tooth autotransplantation in a 10-year-old boy with chronic maxillary rhinosinusitis, diagnosed by the department of otorhinolaryngology. The patient's mandibular second premolars were transplanted to a congenitally edentulous maxillary premolar region. There was insufficient alveolar bone during transplantation because of pneumatization, but normal root development with vertical alveolar bone growth was observed during a 3-year follow-up. Healing of the transplant in the right side without closing of the apex and without signs of obliteration after 4 years is exceptional.

Gummy Smile Correction Using Lingual Orthodontics and Augmented Corticotomy in Extremely Thin Alveolar Housing.

BACKGROUND: Tooth movement out of anatomic limitations was assisted by augmented corticotomy using deproteinized bovine bone mineral. METHODS: Lip protrusion can be reduced by premolar extraction followed by retraction of the anterior teeth. Surgical intervention is appropriate when the alveolar bone housing of the anterior region is insufficient for the tooth movement. In this patient, corticotomy in upper palatal area and anterior segmented osteotomy in the mandible were performed. Anatomic limitation to the retraction was expanded by xenograft. An antero-posterior lingual appliance was used to bodily retract the upper anterior teeth. The gummy smile was resolved by intrusion of upper entire arch using 2 mid-palatal temporary skeletal anchorage devices. RESULTS: New bone formation was observed on palatal side of upper anterior teeth. The teeth were moved into augmented area without fenestration or vitality loss. Lip protrusion was resolved, and the gummy smile was effectively improved. CONCLUSIONS: Orthodontic tooth movement beyond the limitation of the alveolar bone housing can be achieved with surgical assistance, which can be performed under local anesthesia. Without orthognathic surgery, the gummy smile can be reduced using an antero-posterior lingual retractor with mid-palatal skeletal anchorage.

Accurate registration of cone-beam computed tomography scans to 3-dimensional facial photographs.

INTRODUCTION: Registering a 3-dimensional (3D) facial surface scan to a cone-beam computed tomography (CBCT) scan has various advantages. One major advantage is to compensate for the inaccuracy of the CBCT surface data. However, when registering CBCT and 3D facial scans, changes in facial expression, spatial soft-tissue changes, and differences in the patient's positioning can decrease the accuracy of the registration. In this study, we introduce a new 3D facial scanner that is combined with a CBCT apparatus. Our goal was to evaluate the registration accuracy of CBCT and 3D facial scans, which were taken with the shortest possible time between them. METHODS: The experiment was performed with 4 subjects. Each patient was instructed to hold as still as possible while the CBCT scan was taken, followed immediately by the 3D facial surface scan. The images were automatically registered with software. The accuracy was measured by determining the degree of agreement between the soft-tissue surfaces of the CBCT and the 3D facial images. RESULTS: The average surface discrepancy between the CBCT facial surface and 3D facial surface was 0.60 mm (SD, 0.12 mm). Registration accuracy was also visually verified by toggling between the images of the CBCT and 3D facial surface scans while rotating the registered images. CONCLUSIONS: Registration of consecutively taken CBCT and 3D facial images resulted in reliable accuracy.

Chin plate with a detachable C-tube head serves for both osteotomy fixation and orthodontic anchorage.

BACKGROUNDS: This article reports the dual function of a double-Y miniplate with a detachable C-tube head (C-chin plate; Jin Biomed Co., Bucheon, Korea) used to fixate an anterior segmental osteotomy and provide skeletal anchorage during orthodontic tooth movement. METHODS: Cases were selected for this study from patients who underwent anterior segmental osteotomy under local anesthesia. A detachable C-tube head portion was combined with a double-Y chin plate. The double-Y chin plates were fixated between the osteotomy segments and the mandibular base with screws in a conventional way. The C-tube head portion exited the tissue near the mucogingival junction. RESULTS: Biocreative Chin Plates were placed on the anterior segmental osteotomy sites. The device allowed 3 points of fixation: 1, minor postosteotomy vertical adjustment of the segment during healing; 2, minor shift of the midline during healing; and 3, to serve as temporary skeletal anchorage device during the post-anterior segmental osteotomy orthodontic treatment. When tooth movement goals are accomplished, the C-tube head of the chin plate can be easily detached from the fixation miniplate by twisting the head using a Weingart plier under local anesthesia. This dual-purpose device spares the patient from the need for 2 separate installations for stabilization of osteotomy segments. CONCLUSIONS: The dual-purpose double-Y miniplate combined with a C-tube head (Biocreative Chin Plate) provided versatile application of 3 points of post-osteotomy fixation and of temporary skeletal anchorage for orthodontic tooth movement.

Alveolar bone thickness and fenestration of incisors in untreated Korean patients with skeletal class III malocclusion: A retrospective 3-dimensional cone-beam computed tomography study.

PURPOSE: The purpose of this study was to evaluate vertical bone loss and alveolar bone thickness in the maxillary and mandibular incisors of patients with skeletal class III malocclusion. This study also aimed to evaluate the periodontal condition of class III malocclusion patients who had not undergone orthodontic treatment. MATERIALS AND METHODS: The sample included cone-beam computed tomography scans of 24 Korean subjects (3 male and 21 female). Alveolar bone thickness (ABT), alveolar bone area (ABA), alveolar bone loss (ABL), and fenestration of the maxillary and mandibular incisors were measured using 3-dimensional imaging software. RESULTS: All incisors displayed an ABT of less than 1.0 mm from the labial surface to root level 7 (70% of the root length). A statistically significant difference was observed between the mandibular labial and lingual ABAs and between the maxillary labial and mandibular labial ABAs. The lingual ABA of the mandibular lateral incisors was larger than that of the mandibular central incisors. ABL was severe on the labial surface. A statistically significant difference was observed between the maxillary and mandibular labial ABL values(21.8% and 34.4%, respectively). Mandibular lingual ABL (27.6%) was significantly more severe than maxillary lingual ABL (18.3%) (P<0.05). Eighty-two fenestrations were found on the labial surfaces of the incisors, while only 2 fenestrations were observed on the lingual surfaces. Fenestrations were most commonly observed at root level 6. CONCLUSION: Careful evaluation is needed before orthodontic treatment to avoid iatrogenic damage of periodontal support when treating patients with class III malocclusion.

Nanoscale bonding between human bone and titanium surfaces: osseohybridization.

Until now, the chemical bonding between titanium and bone has been examined only through a few mechanical detachment tests. Therefore, in this study, a sandblasted and acid-etched titanium mini-implant was removed from a human patient after 2 months of placement in order to identify the chemical integration mechanism for nanoscale osseointegration of titanium implants. To prepare a transmission electron microscopy (TEM) specimen, the natural state was preserved as much as possible by cryofixation and scanning electron microscope/focused ion beam (SEM-FIB) milling without any chemical treatment. High-resolution TEM (HRTEM), energy dispersive X-ray spectroscopy (EDS), and scanning TEM (STEM)/electron energy loss spectroscopic analysis (EELS) were used to investigate the chemical composition and structure at the interface between the titanium and bone tissue. HRTEM and EDS data showed evidence of crystalline hydroxyapatite and intermixing of bone with the oxide layer of the implant. The STEM/EELS experiment provided particularly interesting results: carbon existed in polysaccharides, calcium and phosphorus existed as tricalcium phosphate (TCP), and titanium existed as oxidized titanium. In addition, the oxygen energy loss near edge structures (ELNESs) showed a possibility of the presence of CaTiO3. These STEM/EELS results can be explained by structures either with or without a chemical reaction layer. The possible existence of the osseohybridization area and the form of the carbon suggest that reconsideration of the standard definition of osseointegration is necessary.

Gene profiling of bone around orthodontic mini-implants by RNA-sequencing analysis.

This study aimed to evaluate the genes that were expressed in the healing bones around SLA-treated titanium orthodontic mini-implants in a beagle at early (1-week) and late (4-week) stages with RNA-sequencing (RNA-Seq). Samples from sites of surgical defects were used as controls. Total RNA was extracted from the tissue around the implants, and an RNA-Seq analysis was performed with Illumina TruSeq. In the 1-week group, genes in the gene ontology (GO) categories of cell growth and the extracellular matrix (ECM) were upregulated, while genes in the categories of the oxidation-reduction process, intermediate filaments, and structural molecule activity were downregulated. In the 4-week group, the genes upregulated included ECM binding, stem cell fate specification, and intramembranous ossification, while genes in the oxidation-reduction process category were downregulated. GO analysis revealed an upregulation of genes that were related to significant mechanisms, including those with roles in cell proliferation, the ECM, growth factors, and osteogenic-related pathways, which are associated with bone formation. From these results, implant-induced bone formation progressed considerably during the times examined in this study. The upregulation or downregulation of selected genes was confirmed with real-time reverse transcription polymerase chain reaction. The RNA-Seq strategy was useful for defining the biological responses to orthodontic mini-implants and identifying the specific genetic networks for targeted evaluations of successful peri-implant bone remodeling.