Slim the face or not: 3D change of facial soft and hard tissues after third molars extraction: a pilot study.

BACKGROUND: Whether slim the face or not after removed third molars is the concern of some orthodontic treatment candidates. The aim of this article is to explore the volume changes of facial soft and hard tissues after third molars extraction, as well as develop a reproducible clinical protocol to precisely assess facial soft tissue volume change. METHODS: A non-randomized, non-blind, self-controlled pilot study was conducted. 24 adults aged 18-30 had ipsilateral third molars extracted. The body weight change was controlled within 2 kg. Structured light scans were taken under a standardized procedure pre-extraction (T0), three (T1), and six (T2) months post-extraction; CBCTs were taken at T0 and T2. The projection method was proposed to measure the soft tissue volume (STV) and the soft tissue volume change (STVC) by the Geomagic software. The hard tissue volume change (HTVC) was measured in the Dragonfly software. RESULTS: The final sample size is 23, including 5 males (age 26.6 ± 2.5 years) and 18 females (age 27.3 ± 2.5 years). The HTVC was - 2.33 ± 0.46ml on the extraction side. On the extraction side, the STV decreased by 1.396 (95% CI: 0.323-2.470) ml (P < 0.05) at T1, and increased by 1.753 (95% CI: -0.01-3.507) ml (P = 0.05) at T2. T2 and T0 had no difference (P > 0.05). The inter and intra-raters ICC of the projection method was 0.959 and 0.974. There was no correlation between the STVC and HTVC (P > 0.05). CONCLUSIONS: After ipsilateral wisdom teeth extraction, the volume of hard tissue on the extraction side reduces, and the volume of facial soft tissue does not change evidently. However, further research with large sample size is still needed. The STV measurement has excellent repeatability. It can be extended to other interested areas, including forehead, nose, paranasal, upper lip, lower lip and chin, which is meaningful in the field of orthodontics and orthopedics. TRIAL REGISTRATION: ChiCTR, ChiCTR1800018305 (11/09/2018), http://www.chictr.org.cn/showproj.aspx?proj=28868 .

Morphologic reproducibility in 6 regions of the 3-dimensional facial models acquired by a standardized procedure: An in vivo study.

INTRODUCTION: A standardized procedure was proposed to control involuntary motion and other factors during the capture of structural light scanning that could influence the morphology of 3-dimensional facial models; interoperator reproducibility was evaluated. METHODS: Twenty subjects volunteered for facial scanning. Three researchers scanned each volunteer 3 times on the same day using the FaceScan structural light scanning system (Isravision, Darmstadt, Germany) and after the proposed procedure. Captures were done at 5-minute intervals. The 3 facial scans acquired by the same researcher were compared by reverse engineering software (Geomagic; 3D Systems, Rock Hill, SC). Six facial regions, including forehead, nose, paranasal, upper lip, lower lip and chin, and cheek, were divided. With the first scan as a reference, the other 2 scans were registered, and surface-to-surface distance maps were acquired to calculate the mean, standard deviation, and root mean squares (RMS) between 2 surfaces. The reproducibility between 3 researchers was then evaluated by a 1-way analysis of variance. RESULTS: The mean of 6 facial regions was close to 0. The RMS of lip regions were largest (0.48-0.53 mm), the forehead was smallest (0.21 mm), and the others ranged 0.37 mm to 0.42 mm. The standard deviation was slightly smaller than RMS and had the same trend of change. There was no significant difference in RMS among the 3 researchers (P >0.05). CONCLUSIONS: With the constraint of the standardized procedure, the morphologic reproducibility of facial models in 6 regions was satisfying.

[Preliminary evaluation on 3-demension changes of facial soft tissue with structure light scanning technique before and after orthognathic surgery of Class III deformities].

OBJECTIVE: To evaluate facial soft tissue 3-deminsion changes of skeletal Class III malocclusion patients after orthognathic surgery using structure light scanning technique. METHODS: Eight patients [3 males and 5 females, aged (27.08 ± 4.42) years] with Class III dentoskeletal relationship who underwent a bimaxillary orthognathic surgical procedure involving advancement of the maxilla by Le Fort I osteotomy and mandibular setback by bilateral sagittal split ramus osteotomy (BSSO) and genioplasty to correct deformity were included. 3D facial images were obtained by structure light scanner for all the patients 2 weeks preoperatively and 6 months postoperatively. The facial soft tissue changes were evaluated in 3-dimension. The linear distances and angulation changes for facial soft tissue landmarks were analyzed. The soft tissue volumetric changes were assessed too. RESULTS: There were significant differences in the sagittal and vertical changes of soft tissue landmarks. The greatest amount of soft tissue change was close to lips. There were more volumetric changes in the chin than in the maxilla, and fewer in the forehead. CONCLUSION: After biomaxillary surgery, there were significant facial soft tissue differences mainly in the sagittal and vertical dimension for skeletal Class III patients. The structure light 3D scanning technique can be accurately used to estimate the soft tissue changes in patients who undergo orthognathic surgery.

Low-intensity pulsed ultrasound reduces alveolar bone resorption during orthodontic treatment via Lamin A/C-Yes-associated protein axis in stem cells.

BACKGROUND: The bone remodeling during orthodontic treatment for malocclusion often requires a long duration of around two to three years, which also may lead to some complications such as alveolar bone resorption or tooth root resorption. Low-intensity pulsed ultrasound (LIPUS), a noninvasive physical therapy, has been shown to promote bone fracture healing. It is also reported that LIPUS could reduce the duration of orthodontic treatment; however, how LIPUS regulates the bone metabolism during the orthodontic treatment process is still unclear. AIM: To investigate the effects of LIPUS on bone remodeling in an orthodontic tooth movement (OTM) model and explore the underlying mechanisms. METHODS: A rat model of OTM was established, and alveolar bone remodeling and tooth movement rate were evaluated via micro-computed tomography and staining of tissue sections. In vitro, human bone marrow mesenchymal stem cells (hBMSCs) were isolated to detect their osteogenic differentiation potential under compression and LIPUS stimulation by quantitative reverse transcription-polymerase chain reaction, Western blot, alkaline phosphatase (ALP) staining, and Alizarin red staining. The expression of Yes-associated protein (YAP1), the actin cytoskeleton, and the Lamin A/C nucleoskeleton were detected with or without YAP1 small interfering RNA (siRNA) application via immunofluorescence. RESULTS: The force treatment inhibited the osteogenic differentiation potential of hBMSCs; moreover, the expression of osteogenesis markers, such as type 1 collagen (COL1), runt-related transcription factor 2, ALP, and osteocalcin (OCN), decreased. LIPUS could rescue the osteogenic differentiation of hBMSCs with increased expression of osteogenic marker inhibited by force. Mechanically, the expression of LaminA/C, F-actin, and YAP1 was downregulated after force treatment, which could be rescued by LIPUS. Moreover, the osteogenic differentiation of hBMSCs increased by LIPUS could be attenuated by YAP siRNA treatment. Consistently, LIPUS increased alveolar bone density and decreased vertical bone absorption in vivo. The decreased expression of COL1, OCN, and YAP1 on the compression side of the alveolar bone was partially rescued by LIPUS. CONCLUSION: LIPUS can accelerate tooth movement and reduce alveolar bone resorption by modulating the cytoskeleton-Lamin A/C-YAP axis, which may be a promising strategy to reduce the orthodontic treatment process.

Stem Cells From Human Exfoliated Deciduous Teeth Alleviate Liver Cirrhosis via Inhibition of Gasdermin D-Executed Hepatocyte Pyroptosis.

Liver cirrhosis represents a type of end-stage liver disease with few effective therapies, which was characterized by damaged functional liver tissue due to long-term inflammation. Gasdermin D (GSDMD)-executed programmed necrosis is reported to be involved in inflammation. However, the role of GSDMD in liver cirrhosis remains unclear. In this study, we used a CCl4-induced cirrhosis model and found stem cells from human exfoliated deciduous teeth (SHED) infusion showed profound therapeutic effects for liver cirrhosis. Mechanistically, NLRP3 inflammasome-activated GSDMD and its pyroptosis were upregulated in liver cirrhosis, while SHED infusion could suppress the expression of GSDMD and Caspase-1, resulting in reduced hepatocyte pyroptosis and inflammatory cytokine IL-1ß release. Consistently, SHED could inhibit the elevated expression of NLRP3, GSDMD and Caspase-1 induced by CCl4 treatment in vitro co-culture system, which was mediated by decreasing reactive oxygen species (ROS) generation. Moreover, the pyroptosis inhibitor disulfiram showed similar therapeutic effects for liver cirrhosis as SHED. In conclusion, SHED alleviates CCl4-induced liver cirrhosis via inhibition of hepatocytes pyroptosis. Our findings could provide a potential treatment strategy and novel target for liver cirrhosis.

Longitudinal changes in mandibular arch posterior space in adolescents with normal occlusion.

INTRODUCTION: The purpose of this study was to investigate the changes of available mandibular space in the posterior dental arch of teenagers from 13 to 18 years old. METHODS: Longitudinal cephalograms of 28 adolescents (13 boys, 15 girls) with normal occlusion, selected from among 901 candidates, were taken annually from 13 to 18 years of age inclusively. Modified analyses with occlusal plane and occlusal plane perpendicular as reference planes were used to evaluate the changes of available space of the posterior mandibular arch. RESULTS: From 13 to 18 years of age, significant differences of mandibular posterior space were found among ages and sexes. The total increases of available space were 5.12 mm in the girls and 5.79 mm in the boys. For girls before age 16 and boys before age 17, the increased available space was contributed mainly by resorption of bone on the anterior border of the ramus. Mesial drift of the dental arch did not occur until the eruption of the third molars. The average available spaces increased 1.22 mm in girls less than age 16 and 1.45 mm in boys less than age 17 per side per year. CONCLUSIONS: The prediction of available space in the posterior mandibular arch should be based on age and sex.

Periodontal Effect of Periodontally Accelerated Osteogenic Orthodontics in Skeletal Angle Class III: A Nonrandomized, Controlled Trial.

The objective of this study was to evaluate the effect of periodontally accelerated osteogenic orthodontics (PAOO) on gingivae and alveolar bone by analysis of clinical and cone beam computed tomography (CBCT) parameters in the treatment of 20 skeletal Class III patients. The patients included in this study were divided into test and control groups. Periodontal parameters such as probing depth (PD), gingival recession (GR), keratinized gingival width, and alveolar bone thickness of CBCT scans were measured and recorded preoperation (T0) and at 6 months postoperative (T1). The difference in PD from T0 to T1 between the two groups was not statistically significant (0.01 ± 0.46 mm vs 0.22 ± 0.65 mm, respectively; P > .05). No significant difference in GR was observed from T0 to T1 between the two groups (0.03 ± 0.26 mm vs -0.03 ± 0.27 mm, respectively; P > .05). Alveolar bone thickness (4 mm apical to the cementoenamel junction [CEJ]) change from T0 to T1 was -0.31 ± 0.35 mm for the control group and 0.06 ± 0.69 mm for the test group (P < .05). Meanwhile, alveolar bone thickness (6 mm apical to CEJ) changes from T0 to T1 were -0.38 ± 0.54 mm and 0.10 ± 0.80 mm for the control and test groups, respectively (P < .05). It was determined that PAOO in the treatment of skeletal Class III patients is effective and safe to periodontium on the basis of clinical and CBCT parameters.

Morphological analysis of the alveolar bone of the anterior teeth in severe high-angle skeletal Class II and Class III malocclusions assessed with cone-beam computed tomography.

OBJECTIVE: This Cross-sectional study used cone-beam computed tomography (CBCT) to evaluate the difference in the alveolar bone of the anterior teeth between high-angle adults with severe skeletal Class II malocclusions and Class III malocclusions. MATERIALS AND METHODS: The CBCT archives from 62 high-angle adults were selected from patients of the Stomatology Hospital of Peking University between October 2017 to January 2018. The 62 high-angle adult subjects were divided into the following 2 groups based on their sagittal jaw relationships: severe skeletal Class II and severe skeletal Class III. Vertical bone level (VBL), alveolar bone area (ABA), and thickness of alveolar bone were measured at 2 mm, 4 mm, and 6 mm below and above to the cemento-enamel junction (CEJ) level, as well as at the apical level. Then, independent samples t-test were conducted for statistical comparisons. RESULTS: In the maxillary incisors, the labial VBL was smaller in the patients in skeletal Class III group than those in skeletal Class II group (P<0.05). On the labial side, the ABA was significantly thinner in patients in skeletal Class II group than those in skeletal Class III group, especially in terms of the maxillary central incisors' ABA at 4 mm and 6 mm above the CEJ level (P<0.05), in terms of apical ABA and total ABA of the maxillary lateral incisors (P<0.05). The alveolar bone thickness around maxillary lateral incisors was significantly thinner in patients of skeletal Class II than that of patients of skeletal Class III, especially regarding the apical level on the labial side (P<0.05). The ABA of the mandibular alveolar bone in the area of the lower anterior teeth was significantly thinner in patients in skeletal Class III group than those in skeletal Class II group, especially in terms of apical ABA, total ABA on the labial and lingual sides, and ABA at 6 mm below the CEJ level on the lingual side (P<0.05). In the mandibular lateral incisors, the alveolar bone thickness was significantly thinner in patients in skeletal Class III group than it was in patients in skeletal Class II group, especially regarding the apical level on the lingual side (P<0.05). CONCLUSIONS: The ABA and the alveolar bone thickness of the mandibular anterior teeth were significantly thinner in the severe high-angle group of skeletal Class III adult patients than in the sample of severe high-angle skeletal Class II adult cases. Our study firstly revealed that the roots of the maxillary central and lateral incisors were placed more labially in the subjects of severe high-angle skeletal Class II than in those of severe high-angle skeletal Class III, especially in the lateral incisors.

Quantitative cervical vertebral maturation assessment in adolescents with normal occlusion: a mixed longitudinal study.

INTRODUCTION: The purpose of this study was to establish a quantitative cervical vertebral maturation (CVM) system for adolescents with normal occlusion. METHODS: Mixed longitudinal data were used. The subjects included 87 children and adolescents from 8 to 18 years old with normal occlusion (32 boys, 55 girls) selected from 901 candidates. Sequential lateral cephalograms and hand-wrist films were taken once a year for 6 years. The lateral cephalograms of all subjects were divided into 11 maturation groups according to the Fishman skeletal maturity indicators. The morphologic characteristics of the second, third, and fourth cervical vertebrae at 11 developmental stages were measured and analyzed. RESULTS: Three characteristic parameters (H4/W4, AH3/PH3, @2) were selected to determine the classification of CVM. With 3 morphologic variables, the quantitative CVM system including 4 maturational stages was established. An equation that can accurately estimate the maturation of the cervical vertebrae was established: CVM stage=-4.13+3.57xH4/W4+4.07xAH3/PH3+0.03x@2. CONCLUSIONS: The quantitative CVM method is an efficient, objective, and relatively simple approach to assess the level of skeletal maturation during adolescence.

Effects of fixed orthodontic brackets on oral malodor: A systematic review and meta-analysis according to the preferred reporting items for systematic reviews and meta-analyses guidelines.

BACKGROUND: This systematic review and meta-analysis aimed to identify whether there is any relationship between fixed orthodontic appliances and malodor, and if self-ligating brackets (SLBs) prevent malodor better than conventional brackets (CBs). METHODS: The electronic databases PubMed, Ovid, EMBASE, and the Cochrane Library were searched from inception to September 2016; a manual search was also performed. Randomized controlled and clinical controlled trials, in which experimental groups received fixed orthodontic therapy and malodor was measured, were included. Patients treated with fixed orthodontic brackets were compared with those without any treatment, and SLB systems were compared with CB systems. Two reviewers independently selected potentially relevant studies, evaluated the risk for bias, extracted essential data, and synthesized findings using Review Manager version 5.3 (Copenhagen: The. Nordic Cochrane Centre, The Cochrane Collaboration, 2014). RESULTS: Four studies, involving a total of 152 participants, met the inclusion criteria. Fixed orthodontic appliances caused malodor from the initial visit to 2 to 3 months, but was only significant after the first week (mean difference 20.24 [95% confidence interval [CI]11.75-28.74]; P < .00001). Plaque index, gingival index, and periodontal pocket depths demonstrated no statistical differences between the SLB and CB groups after the first week. However, SLBs significantly controlled malodor better than CBs after the first week (mean difference 4.32 [95% CI 6.02 to 2.61]; P < .00001). The quality of the included studies was relatively low and relevant research in this field is quite scarce. CONCLUSIONS: Although the evidence base was relatively weak, fixed orthodontic treatment appeared to be a risk factor for malodor, independent of periodontal changes, and SLB systems controlled malodor better than CB systems.

Facial soft tissue changes after nonsurgical rapid maxillary expansion: a systematic review and meta-analysis.

BACKGROUND: The present systematic review and meta-analysis aimed to test the hypothesis that no facial soft tissue changes occur after nonsurgical rapid maxillary expansion (RME), in order to provide a reference for orthodontists. METHODS: PubMed, EMBASE, Cochrane Library, OVID, MEDLINE, CINAHL, Scopus, and ScienceDirect databases were electronically and manually searched up to December 2017, and randomized controlled, clinical controlled trials, cohort studies and retrospective studies where soft tissue changes were measured before and after nonsurgical RME were identified. Study appraisal and synthesis were performed by two reviewers who completed the study selection and quality assessment procedures independently and in duplicate. Data from the involved studies were pooled using Revman 5.3. RESULTS: A total of 1762 articles were identified after the removal of duplicates. After selection and quality assessment, 15 studies met the inclusion criteria for the systematic review, and 13 articles were ultimately included in the meta-analysis. The quality of the involved studies was relatively moderate. Pre-expansion, postexpansion, and postretention data were pooled. The nasal width, alar base width, and distances from the lower lips to the E line showed significant changes after expansion. Moreover, after retention, the nasal width, mouth width, upper philtrum width, and distance from the lower lip to the E line showed significant increases relative to the baseline values. Limitations of the present study included the moderate quality of the included studies and the fact that the results were based on short-term observations of patients in the growth phase. CONCLUSION: Our findings suggest that RME results in a significantly increased nasal width, mouth width, upper philtrum width, and distance from the lower lip to the E line after the retention phase. However, the clinical importance of these findings is questionable.

Magnetic Bead-based Salivary Peptidome Profiling for Accelerated Osteogenic Orthodontic Treatments.

OBJECTIVE: To identify a panel of differentially expressed candidate biomarkers for patients undergoing accelerated osteogenic orthodontics (AOO). METHODS: This study included 36 saliva samples taken from six Class III surgical patients at six time points: the date before the corticotomy procedure (T1) and at 1 week, 2 weeks, 1 month, 2 months and 6 months after the procedure (T2, T3, T4, T5 and T6, respectively). After the maxillary dental arch was aligned and levelled, AOO procedures were performed in the maxillary alveolar bone. Saliva samples were used to create peptide mass fingerprints using matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) combined with magnetic beads. RESULTS: When the six groups were compared, 182 peaks were significantly different (P < 0.01), and the biomarker profiles changed over time. After corticotomy, the mass peaks predicted to be the Apolipoprotein A-I precursor (APOA1) increased sharply in T2 then decreased. The peptides predicted to be complement component 3 decreased in T2, then gradually increased and declined in T6. The peptides predicted to be the vitamin D-binding protein precursor increased in T2, then fell to the preoperative level. The mass peaks of the peptides predicted to be Isoform 1 of the fibrinogen alpha chain precursor (FGA) first decreased, then increased with time. CONCLUSION: The salivary protein profiles changed with accelerated tooth movement induced by AOO. This method provides a tool for investigating corticotomy-induced accelerated tooth movement in humans, and explored the critical factors responsible for the regional acceleratory phenomenon.

Gene editing of the extra domain A positive fibronectin in various tumors, amplified the effects of CRISPR/Cas system on the inhibition of tumor progression.

BACKGROUND: The low efficiency of clustered, regularly interspaced, palindromic repeats-associated Cas (CRISPR/Cas) system editing genes in vivo limits the application. A components of the extracellular matrix (ECM), the extra domain A positive fibronectin (EDA+FN), may be a target for CRISPR/Cas system for the pro-oncogenic effects. The exclusion of EDA exon would alter the microenvironment and inhibit tumor progression, even the frequency of gene editing is still limited. RESULTS: The pro-oncogenic effects were confirmed by the exclusion of EDA exon from the fibronectin gene, as illustrated by the down-regulated proliferation, migration and invasion of CNE-2Z or SW480 cells (P<0.05). Furthermore, although the efficacy of EDA exon knockout through CRISPR/Cas system was shown to be low in vivo, the EDA+FN protein levels decrease obviously, inhibiting the tumor growth rate significantly (P<0.05), which was accompanied by a decrease in Ki-67 expression and microvessel numbers, and increased E-cadherin or decreased Vimentin expression (P<0.05). METHODS AND MATERIALS: Human nasopharyngeal carcinoma cell line CNE-2Z, and the colorectal carcinoma cell line SW480 were transfected with CRISPR/Cas9 plasmids targeting EDA exon. The effects of the exclusion of EDA on the cell proliferation, motility and epithelial-mesenchymal transition (EMT) were investigated, and the western blot and real-time PCR were performed to analyze the underlying mechanisms. Furthermore, CRISPR/Cas9 plasmids were injected into xenograft tumors to knockout EDA exon in vivo, and tumor growth, cell proliferation, EMT rate, or vascularization were investigated using western blot, PCR and immunohistochemistry. CONCLUSION: CRISPR/Cas system targeting ECM components was shown to be an effective method for the inhibition of tumor progression, as these paracrine or autocrine molecules are necessary for various tumor cells. This may represent a novel strategy for overcoming the drug evasion or resistance, in addition, circumventing the low efficiency of CRISPR/Cas system in vivo.

Expression of cancer cell-derived IgG and extra domain A-containing fibronectin in salivary adenoid cystic carcinoma.

OBJECTIVE: Cancer-IgG is a newly-discovered molecule, mainly derived from epithelial carcinoma cells and is significantly correlated with differentiation, metastasis, local invasion, and poor prognosis of many cancers. In our previous study we detected IgG expression in oral epithelial carcinoma, including salivary adenoid cystic carcinoma (SACC), using an IgG-specific commercial antibody. Here, we explored the correlation between cancer-IgG and clinicopathological features of SACC. DESIGN: A total of 68 human SACC tissue specimens and 2 siRNAs were used to analyze the correlation between cancer-IgG and extra domain A (EDA+)-containing fibronectin using the cancer-IgG-specific monoclonal antibody, RP215. RESULTS: We found an unexpected correlation between cancer-IgG and EDA+ fibronectin, both of which showed aberrant expression in SACC tissue samples. Both were highly expressed in SACC with nerve invasion. In our previous study, EDA+ fibronectin overexpression in SACC cells decreased N-cadherin expression. In the present study, we used SACC-83 cells, wherein EDA+ fibronectin is overexpressed and cancer-IgG is knocked down. EDA+ fibronectin expression was reduced with cancer-IgG knockdown, while cancer-IgG expression did not affect EDA+ fibronectin overexpression. Furthermore, knockdown of non-B cell-derived IgG in SACC cells decreased cellular motility (P<0.05) as well as increased E-cadherin and alpha-smooth muscle actin levels. CONCLUSION: The results suggest that cancer IgG potentially regulates EDA+ fibronectin expression, thereby suggesting possible new therapeutic approaches for SACC.

Involvement of non-B cell-derived immunoglobulin G in the metastasis and prognosis of salivary adenoid cystic carcinoma.

Cancer cell-derived immunoglobulin G (cancer-IgG) has been implicated in the pathogenesis and progression of various types of cancer. However, its role in salivary adenoid cystic carcinoma (SACC) remains unclear. The present study aimed to investigate the effects of cancer-IgG on metastasis and prognosis in 96 patients with SACC. Immunohistochemical staining showed that cancer-IgG expression was present in all 96 individual SACC tissues. Additionally, high cancer-IgG expression was significantly correlated with metastasis, nerve invasion and recurrence in SACC (P<0.05). Moreover, cancer-IgG expression was significantly correlated with the survival duration of patients with SACC (P<0.05). Proliferation, cell motility and invasion all decreased significantly following knockdown of cancer-IgG in SACC cells (P<0.05) through population-doubling time, wound healing and transwell invasion assays. Additionally, cancer-IgG-knockdown in SACC cells induced the increased expression of E-cadherin and matrix metalloproteinase 9, and promoted the epithelial-mesenchymal transition, but decreased the expression of F-actin filaments. Taken together, these results showed that the high expression of cancer-IgG was strongly associated with metastasis, recurrence and invasion in SACC, suggesting that cancer-IgG expression could serve as a useful biomarker to predict the prognosis of the disease.

Osteoclastogenesis in Local Alveolar Bone in Early Decortication-Facilitated Orthodontic Tooth Movement.

OBJECTIVE: In the current study, we aimed to investigate the effects of alveolar decortication on local bone remodeling, and to explore the possible mechanism by which decortication facilitates tooth movement. MATERIALS AND METHODS: Forty rabbits were included in the experiment. The left mandible was subjected to decortication-facilitated orthodontics, and the right mandible underwent traditional orthodontics as a control. The animals were sacrificed on the days 1, 3, 5, 7 and 14, after undergoing orthodontic procedures. Tooth movement was measured by Micro-CT, and the local periodontal tissues were investigated using H&E, Masson's trichrome and tartrate-resistant acid phosphatase (TRAP) staining. The mRNA levels of genes related to bone remodeling in the alveolar bone were analyzed using real-time PCR. RESULT: On days 3, 5, 7 and 14, tooth movement was statistically accelerated by decortication (P<0.05) and was accompanied by increased hyperemia. Despite the lack of new bone formation in both groups, more osteoclasts were noted in the decorticated group, with two peak counts (P<0.05). The first peak count was consistent with the maximum values of ctsk and TRAP expression, and the second peak counts accompanied the maximum nfatc1 and jdp2 expression. The increased fra2 expression and the ratio of rankl/opg also accompanied the second peak counts. CONCLUSIONS: Following alveolar decortication, osteoclastogenesis was initially induced to a greater degree than the new bone formation which was thought to have caused a regional acceleratory phenomenon (RAP). The amount of steoclastogenesis in the decorticated alveolar bone was found to have two peaks, perhaps due to attenuated local resistance. The first peak count in osteoclasts may have been due to previously existing osteoclast precursors, whereas the second may represent the differentiation of peripheral blood mononuclear cells which came from circulation as the result of hyperemia.

A pilot clinical study of Class III surgical patients facilitated by improved accelerated osteogenic orthodontic treatments.

OBJECTIVE: To evaluate if the improved accelerated osteogenic orthodontics (IAOO) procedure could speed Class III surgical patients' preoperative orthodontic treatment duration and, if yes, to what extent. This study was also designed to determine whether or not an IAOO procedure affects the tooth-moving pattern during extraction space closure. MATERIALS AND METHODS: The samples in this study consisted of 24 Class III surgical patients. Twelve skeletal Class III surgery patients served as an experimental group (group 1) and the others as a control group (group 2). Before treatment, the maxillary first premolars were removed. For group 1, after the maxillary dental arch was aligned and leveled (T2), IAOO procedures were performed in the maxillary alveolar bone. Except for this IAOO procedure in group 1, all 24 patients experienced similar combined orthodontic and orthognathic treatment. Study casts of the maxillary dentitions were made before orthodontic treatment (T1) and after extraction space closure (T3). All of the casts were laser scanned, and the amount of movement of the maxillary central incisor, canine, and first molar, as well as arch widths, were digitally measured and analyzed by using the three-dimensional model superimposition method. RESULTS: The time durations T3-T2 were significantly reduced in group 1 by 8.65 ± 2.67 months and for T3-T1 were reduced by 6.39 ± 2.00 months (P < .001). Meanwhile, the tooth movement rates were all higher in group 1 (P < .05). There were no significant differences in the amount of teeth movement in the sagittal, vertical, and transverse dimensions between the two groups (P > .05). CONCLUSION: The IAOO can reduce the surgical orthodontic treatment time for the skeletal Class III surgical patient by more than half a year on average. The IAOO procedures do not save anchorage.

[Class III surgical patients facilitated by accelerated osteogenic orthodontic treatment].

OBJECTIVE: To evaluate the treatment time and the anterior and posterior teeth movement pattern as closing extraction space for the Class III surgical patients facilitated by accelerated osteogenic orthodontic treatment. METHODS: There were 10 skeletal Class III patients in accelerated osteogenic orthodontic group (AOO) and 10 patients in control group. Upper first premolars were extracted in all patients. After leveling and alignment (T2), corticotomy was performed in the area of maxillary anterior teeth to accelerate space closing.Study models of upper dentition were taken before orthodontic treatment (T1) and after space closing (T3). All the casts were laser scanned, and the distances of the movement of incisors and molars were digitally measured. The distances of tooth movement in two groups were recorded and analyzed. RESULTS: The alignment time between two groups was not statistically significant. The treatment time in AOO group from T2 to T3 was less than that in the control group (less than 9.1 ± 4.1 months). The treatment time in AOO group from T1 to T3 was less than that in the control group (less than 6.3 ± 4.8 months), and the differences were significant (P < 0.01). Average distances of upper incisor movement (D1) in AOO group and control group were (2.89 ± 1.48) and (3.10 ± 0.95) mm, respectively. Average distances of upper first molar movement (D2) in AOO group and control group were (2.17 ± 1.13) and (2.45 ± 1.04) mm, respectively.No statistically significant difference was found between the two groups (P > 0.05). CONCLUSIONS: Accelerated osteogenic orthodontic treatment could accelerate space closing in Class III surgical patients and shorten preoperative orthodontic time. There were no influence on the movement pattern of anterior and posterior teeth during pre-surgical orthodontic treatment.

Validity and reliability of a method for assessment of cervical vertebral maturation.

OBJECTIVE: To evaluate the validity and reliability of the cervical vertebral maturation (CVM) method with a longitudinal sample. MATERIALS AND METHODS: Eighty-six cephalograms from 18 subjects (5 males and 13 females) were selected from the longitudinal database. Total mandibular length was measured on each film; an increased rate served as the gold standard in examination of the validity of the CVM method. Eleven orthodontists, after receiving intensive training in the CVM method, evaluated all films twice. Kendall's W and the weighted kappa statistic were employed. RESULTS: Kendall's W values were higher than 0.8 at both times, indicating strong interobserver reproducibility, but interobserver agreement was documented twice at less than 50%. A wide range of intraobserver agreement was noted (40.7%-79.1%), and substantial intraobserver reproducibility was proved by kappa values (0.53-0.86). With regard to validity, moderate agreement was reported between the gold standard and observer staging at the initial time (kappa values 0.44-0.61). However, agreement seemed to be unacceptable for clinical use, especially in cervical stage 3 (26.8%). CONCLUSIONS: Even though the validity and reliability of the CVM method proved statistically acceptable, we suggest that many other growth indicators should be taken into consideration in evaluating adolescent skeletal maturation.

[MESH diagrams of Chinese in Beijing and its preliminary application in practice].

OBJECTIVE: To establish the normal MESH diagrams of Chinese in Beijing, and to build a computerized MESH analysis system for orthodontic practice. METHODS: Twenty-eight subjects with normal occlusion were selected in Beijing and their lateral cephalograms were taken at the age of thirteen and eighteen, respectively. Individual MESH diagrams were then established for each subject mainly according to Moorrees' method from the cephalograms orientated in estimated natural head position. Male and female normal MESH diagrams were created. A computerized MESH analysis system was also developed. RESULTS: The normal MESH diagrams of Chinese in Beijing, thirteen and eighteen years old respective, were established. The computerized MESH analysis system was constructed and used in orthodontic patients. CONCLUSIONS: MESH analysis is a proportional analysis method. It can show the results directly, succinctly and holistically. It is also a favorable complement and amendment to the commonly used angle and linear X-ray analysis methods.