Search

Previously, in the case of malocclusion owing to skeletal discrepancy in adults, the amount of tooth movement was limited since there was no reliable skeletal anchorage device. The only way to treat this case was by repositioning the maxilla and mandible via orthognathic surgery, but most patients are reluctant to undergo surgery owing to the risk and expenses incurred. However, with the current introduction and use of miniscrews as temporary anchorage devices, the entire dental arch can be relocated to a target position without surgery, thus broadening the scope of non-surgical orthodontic treatment compared to the past. For a non-surgical approach to improve skeletal discrepancy, anteroposterior, vertical and transverse displacements of the dental arch are necessary. In this case, the localization of the centre of resistance of the whole arch must precede the appliance design with an appropriate biomechanical design. Especially, in the transverse dimension, the envelope of discrepancy is reportedly narrow, and the tooth movement must accompany the orthopaedic correction involving the midpalatal suture expansion. Recently, in adults with transverse maxillomandibular discrepancy, miniscrew-assisted rapid palatal expansion (MARPE) can be performed. Moreover, compared to surgically assisted rapid palatal expansion, MARPE reduces the cost to the patient and achieves clinically acceptable stable maxillary expansion. In this article, we will discuss the role of total arch movement and MARPE in widening the scope of non-surgical orthodontic treatment, despite the inherent limitations of miniscrews' mechanical aspects.

Objective The aim of this study was to evaluate the stability of bimaxillary surgery involving bilateral intraoral vertical ramus osteotomy performed with or without presurgical miniscrew-assisted rapid palatal expansion (MARPE) in adult patients with skeletal Class III malocclusion. Methods A total of 40 adult patients with skeletal Class III malocclusion were retrospectively divided into two groups (n = 20 each) according to the use of MARPE for the correction of transverse maxillomandibular discrepancy during presurgical orthodontic treatment. Serial lateral cephalograms and dental casts were analyzed until 6 months after surgery. Results Before presurgical orthodontic treatment, there was no significant differences in terms of sex and age between groups. However, the difference of approximately 3.1 mm in the maxillomandibular intermolar width was statistically significant (p < 0.001). Two days after surgery, the mandible had moved backward and upward without any significant intergroup difference. Six months after surgery, the maxillary intercanine (2.7 ± 2.1 mm), interpremolar (3.6 ± 2.4 mm), and intermolar (2.0 ± 1.3 mm) arch widths were significantly increased (p < 0.001) relative to the values before presurgical orthodontic treatment in the MARPE group; these widths were maintained or decreased in the control group. However, there was no significant difference in surgical changes and the postsurgical stability between the two groups. No significant correlations existed between the amount of maxillary expansion and postsurgical mandibular movement. Conclusions MARPE is useful for stable and nonsurgical expansion of the maxilla in adult patients with skeletal Class III malocclusion who are scheduled for bimaxillary surgery.

We incorporated zwitterionic materials into light-curable fluoride varnish (LCFV) in order to inhibit biofilm accumulation and prevent dental caries, and the properties of LCFV with three different zwitterionic materials, namely, 2-methacryloyloxyethyl phosphorylcholine (MPC), carboxybetaine methacrylate (CBMA), and sulfobetaine methacrylate (SBMA) polymers (each at a weight percentage of 3%), were compared; unmodified LCFV without any zwitterionic material was used as a control. Material properties including film thickness and degree of conversion (DC) of each type of LCFV were evaluated. In addition, protein-repellent effects and inhibitory effects on Streptococcus mutans adhesion and saliva-derived biofilm accumulation of LCFV were estimated. Finally, the preventive effect of LCFV on enamel demineralization was assessed in vitro on extracted human teeth specimens stored in S. mutans-containing medium. The film thickness of LCFV significantly decreased with the incorporation of zwitterionic materials compared to the control LCFV, whereas there were no significant differences in the DC among all of the LCFV groups. Furthermore, the amount of adsorbed protein, adherent S. mutans colony-forming unit (CFU) counts, and saliva-derived biofilm thickness and biomass were all significantly lower for LCFV with incorporated zwitterionic materials compared with the control. All LCFV groups including the control showed certain preventive effects against enamel demineralization during a 14-day immersion in the medium with S. mutans and sucrose, and the depth of demineralization was significantly lower in LCFV with zwitterionic materials than in the control. Thus, the incorporation of zwitterionic materials such as MPC, CBMA, and SBMA appears to confer superior antifouling effects to LCFV.

This study evaluated the synergetic effect between surface pre-reacted glass-ionomer (SPRG) filler and 2-methacryloyloxyethyl phosphorylcholine (MPC), for inhibiting multi-species biofilm formation, while maintaining or even improving the original beneficial features of SPRG-filled resin-based composite (RBC).MPC (1.5-10wt%) was incorporated into commercial SPRG-filled RBC. Then, the inherent properties of RBC, and ion release and acid-neutralising properties associated with SPRG were investigated. Further, protein adsorptions and bacterial adhesion and viability on the SPRG-filled RBC surfaces were studied using four kinds of oral bacteria; Streptococcus mutans, Actinomyces naeslundii, Veillonella parvula, and Porphyromonas gingivalis. Finally, the thickness and biomass of the human saliva-derived biofilm model cultured on test and control samples were analysed.Addition of MPC content resulted in decreased flexural strength and wettability of SPRG-filled RBC. SPRG-filled RBC released significantly higher amounts of multiple ions as contents of MPC increased. Meanwhile, SPRG-filled RBC with 5-wt% MPC significantly improved acid-neutralising properties than those of other test and control samples (P0.001). SPRG-filled RBC with 3wt% MPC significantly reduced the amount of adsorbed bovine serum albumin and proteins from the brain heart infusion medium as compared to the control (P0.01). A similar trend was observed in the attachment of four types of bacteria and multi-species biofilm (P0.01).Despite limitation in terms of deteriorations of some physical properties, addition of 3% MPC to SPRG-filled RBC leads to inhibition of the attachment of multi-species bacteria on its surface, as well as inhibition of biofilm growth. Moreover, the original important bioactive features of SPRG-filled RBC such as ion release and acid neutralisations are either maintained or improved upon adding MPC.

The properties of underlying substrates influence the quality of an intraoral scan, but few studies have compared the outcomes using common restorative materials. In this study, we aimed to compare the accuracy of digital and conventional impressions recorded for four different dental materials as the substrates. Experimental crowns were produced with a metallic surface (gold or cobalt-chromium alloy (Co-Cr)) or without a metallic surface (zirconia or PMMA (polymethyl methacrylate)). A conventional impression was made in the conventional group (CON group), and gypsum models were subsequently scanned with a tabletop scanner. An intraoral scanner was used to scan the crowns either after applying a powder spray to reduce the surface reflectivity (IOS-P group) or without the powder spray (IOS group). The scans were assessed in three dimensions for precision and trueness. The accuracy did not differ between the CON and IOS groups for the non-metallic crowns. However, it was statistically different for the Co-Cr metallic crown, reducing trueness observed between groups as CON &gt, IOS &gt, IOS-P. The study evidences the differences in outer surface accuracy observed with a change in the substrate material to be imaged using an oral scanner and with the impression method. These findings suggest that the restoration material present in the oral cavity should be considered when selecting an impression-taking method.

The increased demand for marine oil dietary supplements requires rapid and accurate screening to verify product quality and accuracy of label declarations. Simple and rapid procedures, based on spectra from a portable Fourier-transform infrared (FTIR) device and a benchtop FT-near infrared (FT-NIR) spectrometer combined with chemometrics, were developed to: (1) differentiate sources of omega-3 polyunsaturated fatty acids (PUFA) in their natural triacylglycerol (TAG) or concentrated ethyl ester (EE) forms, and (2) quantify six main fatty acids (FA)/FA classes. A partial least squares discriminant analysis (PLS-DA) model developed for ATR-FTIR data was successfully used to classify a large number of representative products (n = 95) as belonging to the TAG or EE classes, or as mixtures of such. Broad-based partial least squares regression (PLSR) models for each of six fatty acid (FA)/FA classes were successfully validated by cross-validation and by using an independent validation test set. For both complementary procedures, PLSR model predictions showed good linear correlations with a reference gas chromatographic method (R2 > 0.91) and excellent predictive qualities for eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). These simple, rapid, and nondestructive spectroscopic procedures have the potential for differentiating between natural and concentrated forms of omega-3 PUFA and verifying the accuracy of label declarations.

Objectives: To determine whether the success rate and primary stability of surface-treated miniscrews differ from those of nontreated miniscrews. Materials and Methods: Patients who required one or more miniscrews for the same reason in each quadrant were recruited into a single-blinded, split-mouth, randomized, controlled trial with a 1:1 allocation ratio. Self-drilling miniscrews with two surface types were used: those with no surface treatment, and those with an acid-etched surface treatment. The cumulative success rate and primary stability of each type of miniscrew were examined, and factors potentially affecting the success and failure of miniscrews were investigated. Results: Forty patients were included in the study, with a total of 98 orthodontic miniscrews. The overall success rate was 88.8%, and the respective success rates for acid-etched and machined surface miniscrews were 91.8% and 85.7%. The respective mean insertion torques were 13.62 ± 5.95 N·cm and 13.38 ± 4 N·cm, and periotest values measured immediately after insertion were −0.50 ± 2.77 for acid-etched miniscrews and −0.28 ± 3.36 for machined surface miniscrews. There was no significant difference in the mean insertion torques and periotest values according to surface treatment and jaw. Conclusions: Neither the success rate nor the primary stability of acid-etched surface miniscrews and machined surface miniscrews differed significantly. There is a high possibility that miniscrews will fall out in patients who have an open bite or those who require total distalization.

This study investigated the association of changes in cementum protein-1 (CEMP-1), dentine phosphoprotein (DPP), and c-terminal cross-linked telopeptide of type I collagen (CTX-I) levels in human gingival crevicular fluid (GCF) under constant load with external root resorption volume and amount of tooth movement. In total, 11 healthy adult patients (mean age, 23.5 years [range, 18.3–37.7]; four men and seven women) were enrolled. GCF samples were obtained from premolars at T0, T1 (1 day), T2 (1 week), T3 (2 weeks), T4 (4 weeks), and T5 (8 weeks) under constant 100-gm buccal tipping force. Opposite premolars were used as controls. Teeth were extracted at T5, followed by quantification of external root resorption volume and histological analysis. In the test group, T5/T0 ratios of CEMP-1 and DPP levels, differential CEMP-1 levels between T5 and T0, and differential DPP levels between T2 and T0 correlated positively with root resorption volume (r = 0.734, 0.730, 0.627, and 0.612, respectively, all p < 0.05). CEMP-1 levels at T0 and T3 correlated negatively with root resorption volume (r = −0.603 and −0.706; all p < 0.05). CTX-I levels at T5 correlated positively with the amount of tooth movement (r = 0.848, p < 0.01). Alterations in CEMP-1 and DPP levels in human GCF at specific timepoints during orthodontic treatment may be associated with different degrees of external root resorption. This study demonstrates that changes in the levels of tissue-specific biomarkers in GCF may facilitate early detection of external root resorption during orthodontic tooth movement.

Becker’s nevus is a relatively common skin lesion with brown hyperpigmentation and hypertrichosis. It may be expressed simultaneously with other cutaneous, muscular, or skeletal defects, such as hypoplasia of the breast or scoliosis, for which the term “Becker’s nevus syndrome” has been proposed. An 8-year-old boy presented with a Becker’s nevus on the right cheek, chin, and upper neck with alveolar bone hypertrophy in the anterior mandible, which led to an anterior crossbite and severe canting of the mandibular anterior teeth. Through orthopedic treatment using a face mask, the anteroposterior jaw relationship was improved. In phase 2 treatment, we corrected the canting of the mandibular anterior teeth with a segmental intrusion of the mandibular anterior right teeth into the hypertrophic alveolar bone area. The facial profile was improved along with acceptable occlusion, and the treatment result was stable at 1 year after the end of the treatment, without any periodontal attachment loss, root resorption of mandibular anterior teeth, or increase in the size of the hypertrophic region. This case report describes the successful comprehensive treatment of a growing patient with skeletal Class III malocclusion and multiple characteristics of Becker’s nevus syndrome.

Objectives To date, the clinical stability of dual-thread orthodontic miniscrews has not been studied. This study aimed to compare the primary stability and long-term clinical success rate of dual-thread and cylindrical orthodontic miniscrews and to examine the association between various clinical factors and the success rate of miniscrews. Materials and Methods A total of 145 cylindrical and 135 dual-thread miniscrews were inserted in the maxillary and mandibular buccal alveolar areas of 142 patients. The torque and Periotest (Siemens, Bensheim, Germany) values were recorded during insertion and removal. The effect of clinical variables such as sex, age, screw design, jaw, side of placement, root proximity, and site of placement on the success rate was examined using logistic regression analysis. Results There was no statistically significant difference (P = .595) in the overall clinical success rate between the two designs, with an overall success rate of 82.1% and 84.4% for the cylindrical and dual-thread miniscrews, respectively. Age and screw-root proximity were significantly associated with failure (P < .05). Conclusions The dual-thread miniscrews did not show superior long-term stability and clinical success rate as compared with the cylindrical miniscrews. The results of this study suggest that patient age and screw-root proximity influence the clinical success rate of miniscrews.

This study sought to test the feasibility of a newly developed plane called computed modified absolute mandibular midsagittal plane (cmAMP) based on the similarity index (SI) for evaluating the stereoscopical symmetry of the mandible by comparison with other proposed midsagittal planes. This study involved 29 adult patients (15 men, 14 women, average age, 23.1 &plusmn, 6.9 years) with skeletal Class III facial asymmetry who underwent bimaxillary orthognathic surgery. Using cone-beam computed tomography images taken before and 1 year after surgery, cmAMP with the highest SI value between the two anterior segments of the hemi-mandible was set by a computer algorithm. Results show that the SI using cmAMP had the highest value (0.83 &plusmn, 0.04) before surgery compared to the other midsagittal planes, and was not significantly different from the SI (0.80 &plusmn, 0.05) using a facial midsagittal plane (MSP) after surgery. The distance (1.15 &plusmn, 0.74 mm) and angle (2.02 &plusmn, 0.82&deg, ) between MSP and cmAMP after surgery were significantly smaller than those between MSP and other midsagittal planes. In conclusion, the cmAMP plane best matches the two anterior segments of hemi-mandible symmetrically and is the closest to MSP after orthognathic surgery in skeletal Class III patients with facial asymmetry.

The plane formed by the intersection of bilateral porions (PoR and PoL) and left orbitale (OrL) is conventionally defined as the Frankfort horizontal (FH) plane. We aim to test the influence of the FH plane definition on a 3D cephalometric assessment. We selected 38 adult patients (20 males, 18 females, average age: 22.87 &plusmn, 5.17 years) without any gross asymmetry from retrospective records and traced and analyzed their cone-beam computed tomographic images. The findings were categorized into the following four groups: FH1: conventional, FH2: PoR, PoL, right orbitale (OrR), FH3: OrR, OrL, PoL, FH4: OrR, OrL, PoR. The average menton (Me) deviation from the MSP was statistically significant for the FH1 group (0.56 &plusmn, 0.27 mm, p &lt, 0.001), compared to the FH3 (1.37 &plusmn, 1.23 mm) and FH4 (1.33 &plusmn, 1.16 mm) groups. The spatial orientation level (SOL) of the FH plane showed a marked difference (p &lt, 0.05) between the FH2 (0.602&deg, &plusmn, 0.503&deg, ) and FH4 (0.944&deg, 0.778&deg, ) groups. The SOL of the MSP was comparatively small (p &lt, 0.001) for FH2 (0.015&deg, 0.023&deg, ) in comparison to both FH 3 (0.644&deg, 0.546&deg, ) and FH 4 (0.627&deg, 0.516&deg, ). Therefore, the FH plane definition can significantly influence the interpretation of cephalometric findings. Future studies should focus on standardization to improve the reliability and reproducibility of 3D cephalometry.

Flowable resins used for dental restoration are subject to biofilm formation. Zinc has antibacterial properties. Thus, we prepared a zinc-doped phosphate-based glass (Zn-PBG) to dope a flowable resin and evaluated the antibacterial activity of the composite against Streptococcus mutans (S. mutans) to extrapolate the preventative effect toward secondary caries. The composites were prepared having 0 (control), 1.9, 3.8, and 5.4 wt.% Zn-PBG. The flexural strength, elastic modulus, microhardness, depth of cure, ion release, inhibition zone size, and number of colony-forming units were evaluated and analyzed using ANOVA. The flexural strength of the control was significantly higher than those of Zn-PBG samples (p &lt, 0.05). However, all samples meet the International Standard, ISO 4049. The microhardness was not significantly different for the control group and 1.9 and 3.8 wt.% groups, but the 5.4 wt.% Zn-PBG group had a significantly lower microhardness (p &lt, 0.05). Further, the composite resins increasingly released P, Ca, Na, and Zn ions with an increase in Zn-PBG content (p &lt, 0.05). The colony-forming unit count revealed a significant reduction in S. mutans viability (p &lt, 0.05) with increase in Zn-PBG content. Therefore, the addition of Zn-PBG to flowable composite resins enhances antibacterial activity and could aid the prevention of secondary caries.

Since pits and fissures are the areas most commonly affected by caries due to their structural irregularity, bioactive resin-based sealant (RBS) may contribute to the prevention of secondary caries. This study aims to investigate the mechanical, physical, ion-release, enamel remineralisation, and antibacterial capabilities of the novel RBS with bioactive glass (BAG) and 2-methacryloyloxyethyl phosphorylcholine (MPC). For the synthesis, 12.5 wt% BAG and 3 wt% MPC were incorporated into RBS. The contact angle, flexural strength, water sorption, solubility, and viscosity were investigated. The release of multiple ions relating to enamel remineralisation was investigated. Further, the attachments of bovine serum albumin, brain heart infusion broth, and Streptococcus mutans on RBS were studied. Finally, the thickness and biomass of a human saliva-derived microsm biofilm model were analysed before aging, with static immersion aging and with thermocycling aging. In comparison to commercial RBS, BAG+MPC increased the wettability, water sorption, solubility, viscosity, and release of multiple ions, while the flexural strength did not significantly differ. Furthermore, RBS with MPC and BAG+MPC significantly reduced protein and bacteria adhesion and suppressed multi-species biofilm attachment regardless of the existence of aging and its type. The novel RBS has great potential to facilitate enamel remineralisation and suppress biofilm adhesion, which could prevent secondary dental caries.

This study aims to compare the torque values for various lengths of the titanium-based orthodontic anchor screw (OAS), different anchorage methods and varying artificial bone densities after predrilling. Furthermore, the effects of these parameters on bone stability are evaluated. A total of 144 OASs were prepared with a diameter of 1.6 mm and heights of 6, 8 and 10 mm. Artificial bones were selected according to their density, corresponding to Grades 50, 40 and 30. Torque values for the automatic device and manual anchorage methods exhibited a statistically significant difference for the same-sized OAS, according to the bone density of the artificial bones (p &lt, 0.05). However, when insertion torque was at the maximum rotations, there was no significant difference in the torque values for the Grade 30 artificial bone (p &gt, 0.05). When the torque values of both anchorage methods were statistically compared with the mean difference for each group, the results of the manual anchorage method were significantly higher than those of the automatic device anchorage method (p &lt, 0.05). A statistically significant difference was observed in the bone stability resulting from different OAS anchorage methods and artificial bone lengths. These findings suggest that the automatic anchorage method should be used when fixing the OAS.

Prevention of dental caries is a key research area, and improvement of the pit and fissure sealants used for caries prevention has been of particular interest. This report describes results of incorporating a zwitterion, sulfobetaine methacrylate (SB), into photo-polymerized resin-based sealants to enhance resistance to cariogenic bacteria and protein adhesion. Varying amounts (1.5&ndash, 5 wt%) of SB were incorporated into a resin-based sealant, and the flexural strength, wettability, depth of cure, protein adhesion, bacterial viability, and cell cytotoxicity of the resultant sealants were evaluated. The flexural strength decreased with the increasing SB content, but this decrease was statistically significant only for sealants containing &ge, 3 wt% SB. Incorporating a zwitterion led to a significant reduction in the water contact angle and protein adhesion. The colony-forming unit count showed a significant reduction in the bacterial viability of S. mutans, which was confirmed with microscopic imaging. Moreover, cell cytotoxicity analysis of SB-modified sealants using an L929 fibroblast showed a cytotoxicity comparable to that of an unmodified control, suggesting no adverse effects on the cellular metabolism upon SB introduction. Hence, we conclude that the addition of 1.5&ndash, 3 wt% SB can significantly enhance the inherent ability of sealants to resist S. mutans adhesion and prevent dental caries.

It is essential for 3D-printed intra-oral appliances to be able to withstand the mechanical and microbial insult existent in the harsh environment of the oral cavity. Poly(methyl methacrylate) (PMMA)-based appliances are widely used in dentistry. Hence, the present study aimed to evaluate the role of nanodiamonds (NDs) as fillers to enhance the resistance to friction and wear. Using a solution-based mixing technique, 0.1 wt% ND was incorporated into the PMMA, and specimens were 3D-printed for tribological and bacterial analysis. The control specimens without ND fillers were tested against specimens with both amine-functionalized NDs (A-ND) and pure non-functionalized NDs (ND). The surface hardness test revealed a statistically significant increase in the Vickers micro-hardness (p 0.001) in the nanocomposite groups. There was a significant reduction in the coefficient of friction (COF) (p 0.01) in both the ND and A-ND nanocomposites compared to the stainless steel (SS) counter surfaces. However, for titanium (Ti)-based specimens, the COF of the control group was similar to that of A-ND but lower than that of ND. The wear resistance evaluation revealed that both the ND and A-ND groups displayed enhanced resistance to surface loss in comparison to the controls for both SS and Ti counter-surfaces (p 0.001). Furthermore, both A-ND and ND exhibited significantly enhanced resistance to the formation of Streptococcus mutans biofilms after 48 h (p 0.01) compared to the control group. Hence, we concluded that the addition of 0.1 wt% ND in the PMMA-based resin for 3D printing resulted in significant improvement in properties such as COF, wear resistance, and resistance to S. mutans, without any notable impact associated with the functionalization of the NDs.

Purpose The aim of the present study was to compare the long-term stability of bimaxillary surgery using an intraoral vertical ramus osteotomy (IVRO) with and without presurgical orthodontic treatment. Materials and Methods The present retrospective study included 31 consecutive patients with skeletal Class III malocclusions who had undergone bimaxillary surgery (Le Fort I osteotomy and bilateral IVRO). Patients were divided into 2 groups based on treatment type: pre-orthodontic orthognathic surgery (POGS; n = 17) and conventional surgery with presurgical orthodontic treatment (CS; n = 14). Lateral cephalograms were obtained before surgery, 1 day after surgery, 1 month after surgery, 1 year after surgery, and 2 years after surgery to evaluate skeletal and soft tissue changes between the 2 groups. Data were analyzed using χ2 tests, Mann-Whitney U tests, repeated-measures analyses of variance, and independent t tests. Results There was no significant difference in skeletal or soft tissue measurements—with the exception of the angle between the sella-and-nasion plane and the occlusal plane (SN-OP; P Conclusions These findings suggest that POGS and CS have similar long-term stability in patients with skeletal Class III malocclusion.

Herein we evaluate the effect of nanodiamond (ND) incorporation on the mechanical properties of poly(methyl methacrylate) (PMMA) nanocomposite. Three quantities of ND (0.1, 0.3, and 0.5 wt.%) were tested against the control and zirconium oxide nanoparticles (ZrO). Flexural strength and elastic modulus were measured using a three-point bending test, surface hardness was evaluated using the Vickers hardness test, and surface roughness was evaluated using atomic force microscopy (AFM), while fungal adhesion and viability were studied using Candida albicans. Samples were also analyzed for biofilm thickness and biomass in a saliva-derived biofilm model. All groups of ND-PMMA nanocomposites had significantly greater mean flexural strengths and statistically improved elastic modulus, compared to the control and ZrO groups (P &lt, 0.001). The Vickers hardness values significantly increased compared to the control group (P &lt, 0.001) with 0.3% and 0.5% ND. ND addition also gave significant reduction in fungal adhesion and viability (P &lt, 0.001) compared to the control group. Finally, salivary biofilm formation was markedly reduced compared to the ZrO group. Hence, the incorporation of 0.1&ndash, 0.5 wt.% ND with auto- polymerized PMMA resin significantly improved the flexural strength, elastic modulus, and surface hardness, and provided considerable fungal resistance.

Objective The aim of this study was to evaluate the stress distribution and displacement of various craniofacial structures after nonsurgical rapid palatal expansion (RPE) with conventional (C-RPE), bone-borne (B-RPE), and miniscrew-assisted (MARPE) expanders for young adults using three-dimensional finite element analysis (3D FEA). Methods Conventional, bone-borne, and miniscrew-assisted palatal expanders were designed to simulate expansion in a 3D FE model created from a 20-year-old human dry skull. Stress distribution and the displacement pattern for each circumaxillary suture and anchor tooth were calculated. Results The results showed that C-RPE induced the greatest stress along the frontal process of the maxilla and around the anchor teeth, followed by the suture area, whereas B-RPE generated the greatest stress around the miniscrew, although the area was limited within the suture. Compared with the other appliances, MARPE caused relatively even stress distribution, decreased the stress on the buccal plate of the anchor teeth, and reduced tipping of the anchor teeth. Conclusions The findings of this study suggest that the incorporation of miniscrews in RPE devices may contribute to force delivery to the sutures and a decrease in excessive stress on the buccal plate. Thus, MARPE may serve as an effective modality for the nonsurgical treatment of transverse maxillary deficiency in young adults.

Summary Assessing changes in patient's psychological health and oral health-related quality of life (OHRQoL) over time during orthodontic treatment may help clinicians to treat patients more carefully. To evaluate changes in mental health, self-reported masticatory ability and OHRQoL during orthodontic treatment in adults, this prospective study included 66 adults (30 men, 36 women; mean age, 24·2 ± 5·2 years). Each patient completed the Korean versions of the State–Trait Anxiety Inventory, Zung Self-Rating Depression Scale, Rosenberg self-esteem scale, key subjective food intake ability (KFIA) test for five key foods and Oral Health Impact Profile-14 (OHIP-14K) at baseline (T0), 12 months after treatment initiation (T1) and debonding (T2). All variables changed with time. Self-esteem and the total OHIP-14K score significantly decreased and increased, respectively, at T1, with a particular increase in the psychological and social disabilities scores. There were no significant differences in any questionnaire scores before and after treatment. The total OHIP-14K score was positively correlated with trait anxiety and depression, and negatively correlated with self-esteem and KFIA at T0, regardless of the treatment duration. Older patients showed a significant increase in the total OHIP-14K score at T1 and T2. OHRQoL worsened with an increase in the treatment duration. Our results suggest that OHRQoL temporarily deteriorates, with the development of psychological and social disabilities, during orthodontic treatment. This is related to the baseline age, psychological health and self-reported masticatory function. However, patients recover once the treatment is complete.

OBJECTIVE The purpose of this study was to compare the changes induced in the pharyngeal airway space by orthodontic treatment with bodily retraction of the mandibular incisors and mandibular setback surgery without extraction. METHODS This retrospective study included 63 adult patients (32 men and 31 women). Thirty-three patients who had been treated via four-bicuspid extraction and bodily retraction of the mandibular incisors (incisor retraction, IR group) were compared with 30 patients who had been treated via mandibular setback surgery (MS group) without extraction. Lateral cephalograms were acquired and analyzed before (T1) and after treatment (T2). RESULTS The superior pharyngeal airway space did not change significantly in either group during treatment. The middle pharyngeal airway space decreased by 1.15 ± 1.17 mm and 1.25 ± 1.35 mm after treatment in the IR and MS groups, respectively, and the decrease was comparable between the two groups. In the MS group, the inferior pharyngeal airway space (E-IPW) decreased by 0.88 ± 1.67 mm after treatment (p < 0.01). The E-IPW was larger in the MS group than in IR group at T1, but it did not differ significantly between the two groups at T2. No significant correlation was observed between changes in the pharyngeal airway space and the skeletal and dental variables in each group. CONCLUSIONS The middle pharyngeal airway space decreased because of the posterior displacement of the mandibular incisors and/or the mandibular body. The E-IPW decreased only in the MS group because of the posterior displacement of only the mandibular body.

The application of 3D imaging is at its cusp in craniofacial diagnosis and treatment planning. However, most applications are limited to simple subjective superimposition-based analysis. As the diagnostic accuracy dictates the precision in operability, we propose a novel method that enables objective clinical decision making for patients with mandibular asymmetry. We analyzed cone-beam computed tomography (CBCT) scans of 34 patients who underwent surgical correction for mandibular asymmetry using a high-throughput computing algorithm. Radiomic segmentation of quantitative features of surface and volume followed by exploration resulted in identification of a computed modified absolute mandibular midsagittal plane (cmAMP). Tomographic similarity scan (ToSS) curves were generated via bilateral equidistant scanning in an antero-posterior direction with cmAMP as the reference. ToSS comprised of a comprehensive similarity index (SI) score curve and a segment-wise volume curve. The SI score was computed using the Sørensen-Dice similarity coefficient ranging from 0 to 1. The volumetric analysis was represented as the non-overlapping volume (NOV) and overlapping volume (OV) for each segment, with two segmentation lines, at the mental foramen anteriorly and the intraoral vertical ramus osteotomy region posteriorly. Statistical analysis showed strong negative correlation between the NOV and SI scores for the anterior, middle, and total mandible (P 0.001). Additionally, a significant correlation was observed between the change in the SI scores for anterior (P = 0.044) and middle segments (P 0.001) to the total mandible when comparing the data before and after the surgery. This work demonstrated the potential of incorporating ToSS curves in surgical simulation software to improve precision in the clinical decision-making process.

OBJECTIVE The aim of this study was to compare recycled and unused orthodontic miniscrews to determine the feasibility of reuse. The comparisons included both miniscrews with machined surfaces (MS), and those with etched surfaces (ES). METHODS Retrieved MS and ES were further divided into three subgroups according to the assigned recycling procedure: group A, air-water spray; group B, mechanical cleaning; and group C, mechanical and chemical cleaning. Unused screws were used as controls. Scanning electron microscopy, energy-dispersive X-ray spectrometry, insertion time and maximum insertion torque measurements in artificial bone, and biological responses in the form of periotest values (PTV), bone-implant contact ratio (BIC), and bone volume ratio (BV) were assessed. RESULTS Morphological changes after recycling mainly occurred at the screw tip, and the cortical bone penetration success rate of recycled screws was lower than that of unused screws. Retrieved ES needed more thorough cleaning than retrieved MS to produce a surface composition similar to that of unused screws. There were no significant differences in PTV or BIC between recycled and unused screws, while the BV of the former was significantly lower than that of the latter (p < 0.05). CONCLUSIONS These results indicate that reuse of recycled orthodontic miniscrews may not be feasible from the biomechanical aspect.

Purpose Few studies have evaluated the relapse pattern of intraoral vertical ramus osteotomy (IVRO) for the correction of mandibular prognathism with a high angle. The aim of this study was to measure the association between vertical facial types (high and normal mandibular plane angle) and relapse after IVRO for the management of mandibular prognathism. Materials and Methods The retrospective cohort study sample (skeletal Class III patients) was divided into 2 groups according to the angle of the sella-nasion plane relative to the mandibular plane (SN-MP) at the initial examination. Lateral cephalograms were analyzed for the predictor (facial type) and outcome (cephalometric changes over time) variables before surgery, 7 days after surgery, and 12 months after surgery. The 2 groups were matched for sample size (n = 20 in each). Data were analyzed using repeated-measures analysis of variance with Bonferroni correction. Results The normal-angle group (group N, SN-MP from 27° to 37°) and high-angle group (group H, SN-MP >37°) were not significantly different in terms of gender and age at the initial examination. Seven days after surgery, the mandibles in group H moved 2.5 mm more superiorly than those in group N (P = .013); consequently, the amount of overbite correction in group H was approximately 2 mm greater than that in group N (P = .002). Nevertheless, 12 months after surgery, there was no statistically significant difference in relapse of the maxilla and mandible between the 2 groups. In the 2 groups, the mandible moved approximately 0.7 mm superiorly during retention. Conclusions These findings suggest that IVRO is a clinically acceptable and stable treatment modality for mandibular prognathism with a high angle.

The aim of this study was to evaluate differences in the maxillary sinus floor levels between adults with an anterior open bite and those without.This retrospective study included 30 subjects: 15 adults with an anterior open bite (mean age, 21.5 ± 4.3 years) and 15 control subjects with normal occlusion (mean age, 21.7 ± 3.1 years). Cone-beam computed tomography and lateral cephalograms were analyzed before treatment.The open-bite group exhibited a significantly greater maxillary posterior alveolar height (P 0.05). The craniocaudal heights of the maxillary sinus in the region between the first and second molars and between the second premolar and first molar were significantly greater in the open bite group (40.5 and 39.0 mm, respectively) than in the control group (36.7 and 34.7 mm, respectively; P 0.05 for both). The basal bone heights in the regions between the first and second molars, the second premolar and first molar, and the first and second premolars were significantly smaller in the open-bite group than in the control group (P 0.001 for all).Vertical pneumatization of the maxillary sinus floor in the region between the first and second molars and between the second premolar and first molar is greater in adults with an anterior open bite than in those without, whereas basal bone height in the maxillary posterior region is lower in the open-bite patients.

The few studies on craniofacial complex changes in adults have reported contradictory findings. The aim of this study was to radiographically evaluate changes in the craniofacial complex and alveolar bone height of young adults over a 4-year period. This prospective study included 82 young adults (62 men; mean age, 19.0 ± 0.8 years; 20 women; mean age, 18.8 ± 0.9 years). Three radiographic examinations were performed longitudinally: the first (T0) was conducted at the start of the study, the second (T1) was conducted 2 years later, and the third (T2) was conducted at the end of the study period. As part of these examinations, lateral cephalograms, maxillary and mandibular anterior periapical radiographs, and bilateral posterior bitewing radiographs were obtained. During the 4-year follow-up period, all linear cephalometric measurements were significantly greater in men than in women. The amount of increase in the anterior facial height between T1 and T2 was lower in women than in men (P = 0.029). The rate of uprighting of the upper incisors was lower in men than in women over time (P = 0.020). The apex of the nose moved inferiorly between T0 and T2 (P = 0.006). The average overall change in the alveolar bone height was 0.27 mm and the yearly change was 0.07 mm over the 4-year period (P< 0.001). Significant changes in the skeletal, dental, and soft tissue, as well as, natural changes in alveolar bone, occur in young adults over time. Clin. Anat. 29:1011-1017, 2016. © 2016 Wiley Periodicals, Inc.

Objective The aim of this study was to determine the optimal loading conditions for pure intrusion of the six maxillary anterior teeth with miniscrews according to alveolar bone loss. Methods A three-dimensional finite element model was created for a segment of the six anterior teeth, and the positions of the miniscrews and hooks were varied after setting the alveolar bone loss to 0, 2, or 4 mm. Under 100 g of intrusive force, initial displacement of the individual teeth in three directions and the degree of labial tilting were measured. Results The degree of labial tilting increased with reduced alveolar bone height under the same load. When a miniscrew was inserted between the two central incisors, the amounts of medial-lateral and anterior-posterior displacement of the central incisor were significantly greater than in the other conditions. When the miniscrews were inserted distally to the canines and an intrusion force was applied distal to the lateral incisors, the degree of labial tilting and the amounts of displacement of the six anterior teeth were the lowest, and the maximum von Mises stress was distributed evenly across all the teeth, regardless of the bone loss. Conclusions Initial tooth displacement similar to pure intrusion of the six maxillary anterior teeth was induced when miniscrews were inserted distal to the maxillary canines and an intrusion force was applied distal to the lateral incisors. In this condition, the maximum von Mises stresses were relatively evenly distributed across all the teeth, regardless of the bone loss.

Evaluation of facial asymmetry generally involves landmark-based analyses that cannot intuitively assess differences in three-dimensional (3D) stereoscopic structures between deviation and non-deviation sides. This study tested a newly developed similarity index that uses a mirroring technique to intuitively evaluate 3D mandibular asymmetry, and characterised the resulting lower facial soft tissue asymmetry. The similarity index was used to evaluate asymmetry before and after surgery in 46 adult patients (27 men, 19 women; age, 22 ± 4.8 years) with skeletal Class III malocclusion and facial asymmetry who underwent conventional bimaxillary orthognathic surgery. Relative to the midsagittal plane used as the reference plane, the non-overlapping volume of the mandible significantly decreased, and the similarity index significantly increased after surgery. Similarity indexes of the mandible and lower facial soft tissue were strongly negatively correlated with non-overlapping volumes of each measurement. Differences in bilateral hemi-mandibular and hemi-lower facial soft tissue surface and volume measurements before surgery were significantly negatively correlated with similarity indexes of the mandible before and after surgery. This newly developed similarity index and non-overlapping volume using a mirroring technique can easily and intuitively evaluate overall 3D morphological discrepancies, especially 3D mandibular asymmetry, before and after surgery in skeletal Class III patients with facial asymmetry.

The aim of this research was to verify that ultraviolet light (UV)-photofunctionalization improves the success rate and biomechanical stability of miniscrews regardless of length, and to evaluate the comparability of biomechanical stability between UV-photofunctionalized miniscrews with short lengths and untreated miniscrews with conventional lengths.Eight male beagles (age, 12-15 months; weight, 10-13 kg) received a total of 64 miniscrews, including 7-mm and 4-mm untreated and UV-photofunctionalized, acid-etched miniscrews with the use of a random block design. The cumulative success rates were examined in all studied groups. The insertion and removal torques and screw mobility were measured. Microcomputed tomographic scans and histomorphometric analyses were performed at 8 weeks postoperatively.The success rates of 7-mm UV-untreated and UV-photofunctionalized miniscrews were 87.5% and 100%, respectively, vs 43.8% for the 4-mm UV-untreated and 4-mm UV-photofunctionalized miniscrews. The rates were significantly different in accordance with the length (P 0.001). There were no differences in the insertion and removal torque and screw mobility between groups according to the length or UV treatment. However, the 4-mm UV-untreated miniscrews yielded a mean bone area ratio of 6.35 ± 7.43%, whereas the 7-mm UV-photofunctionalized miniscrew yielded a mean ratio of 32.17 ± 8.34% (P = 0.037).The UV-photofunctionalization significantly increased the biomechanical stability and led to increased bone and miniscrew contact area in dogs with miniscrews of the same length. However, the most important factor that affected the success rate of the miniscrew was the length.

We evaluated the efficacy of light-curable fluoride varnish (LCFV) that contains 2-methacryloyloxyethyl phosphorylcholine (MPC) in terms of anti-biofouling properties and prevention of tooth enamel demineralization. MPC was mixed with and incorporated into LCFV at 0 (control), 1.5, 3.0, 5.0, 10.0, 20.0, and 40.0 weight percentage (wt%). Addition of high wt% of MPC resulted in increased film thickness and decreased the degree of conversion, indicating loss of the advantageous properties of LCFV. Addition of 1.5, 3, or 5 wt% MPC significantly reduced the amount of bovine serum albumin adsorbed from a solution and proteins adsorbed from brain heart infusion medium compared to the control (P Streptococcus mutans cells adhered on the surface of LCFV with 1.5, 3, or 5 wt% MPC (P Actinomyces naeslundii and Streptococcus sanguinis adherence to LCFV with 3 wt% MPC. Finally, bacterial adhesion, surface microhardness loss, and the depth of demineralization were substantially lower on bovine tooth enamel surface coated with LCFV containing 3 wt% of MPC than in the control treatment (0 wt% MPC). Therefore, this novel LCFV containing a low concentration of MPC (e.g., 3 wt%) would be effective in anti-biofouling while maintaining the important advantageous features of light-curable fluoride in preventing demineralization.

Introduction We evaluated soft-tissue thickness changes after bimaxillary surgery according to vertical facial patterns in patients with skeletal Class III malocclusion with mandibular prognathism. Methods Forty-three Korean patients (16 men and 27 women; mean age, 22.6 ± 4.1 years) with skeletal Class III malocclusion who underwent bimaxillary surgery were divided into 2 groups: normal-angle group (N group) and high-angle group (H group), on the basis of the presurgical angle of the mandibular plane relative to the sella-nasion plane (SN-MP). Changes in hard-tissue landmarks and soft-tissue thickness before and after surgery were analyzed from reconstructed 3-dimensional cone-beam computed tomography images. Postoperative soft-tissue thickness in both groups was compared with that in 40 patients with normal skeletal Class I malocclusion in the reference group. Results Group N (27°-37°) and group H (>37°) did not differ significantly in terms of sex and age before surgery. Preoperative pogonion (Pog) thickness was significantly less in group H (9.7 ± 1.6 mm) than in group N (10.8 ± 1.9 mm) (P = 0.042). Adjusted multiple linear regression analysis showed a weak positive linear relationship between the SN-MP before surgery and soft-tissue Pog thickness change (R2 of 0.361; P = 0.001) after surgery, but the area below the lower lips was not completely normalized despite surgery. Conclusions The thickness of the soft-tissue Pog may increase slightly after surgery in patients with skeletal Class III malocclusion with a higher preoperative mandibular plane angle, but normalization in the area cannot be completely achieved despite surgery.

Poly(methyl methacralyate) (PMMA) has long been used in dentistry as a base polymer for dentures, and it is recently being used for the 3D printing of dental materials. Despite its many advantages, its susceptibility to microbial colonization remains to be overcome. In this study, the interface between 3D-printed PMMA specimens and oral salivary biofilm was studied following the addition of zwitterionic materials, 2-methacryloyloxyethyl phosphorylcholine (MPC) or sulfobetaine methacrylate (SB). A significant reduction in bacterial and biofilm adhesions was observed following the addition of MPC or SB, owing to their protein-repellent properties, and there were no significant differences between the two test materials. Although the mechanical properties of the tested materials were degraded, the statistical value of the reduction was minimal and all the properties fulfilled the requirements set by the International Standard, ISO 20795-2. Additionally, both the test materials maintained their resistance to biofilm when subjected to hydrothermal fatigue, with no further deterioration of the mechanical properties. Thus, novel 3D-printable PMMA incorporated with MPC or SB shows durable oral salivary biofilm resistance with maintenance of the physical and mechanical properties.

Biofilms are formed on surfaces inside the oral cavity covered by the acquired pellicle and develop into a complex, dynamic, microbial environment. Oral biofilm is a causative factor of dental and periodontal diseases. Accordingly, novel materials that can resist biofilm formation have attracted significant attention. Zwitterionic polymers (ZPs) have unique features that resist protein adhesion and prevent biofilm formation while maintaining biocompatibility. Recent literature has reflected a rapid increase in the application of ZPs as coatings and additives with promising outcomes. In this review, we briefly introduce ZPs and their mechanism of antifouling action, properties of human oral biofilms, and present trends in anti-biofouling, zwitterionic, dental materials. Furthermore, we highlight the existing challenges in the standardization of biofilm research and the future of antifouling, zwitterated, dental materials.

The increasing demand for orthodontic treatment over recent years has led to a growing need for the retrieval and reuse of titanium-based miniscrews to reduce the cost of treatment, especially in patients with early treatment failure due to insufficient primary stability. This in vitro study aimed to evaluate differences in the primary stability between initially inserted and re-inserted miniscrews within different cortical bone densities. Artificial bone was used to simulate cortical bone of different densities, namely 20, 30, 40, and 50 pound per cubic foot (pcf), where primary stability was evaluated based on maximum insertion torque (MIT), maximum removal torque (MRT), horizontal resistance, and micromotion. Scanning electron microscopy was used to evaluate morphological changes in the retrieved miniscrews. The MIT, MRT, horizontal resistance, and micromotion was better in samples with higher cortical bone density, thereby indicating better primary stability (P &lt, 0.05). Furthermore, a significant reduction of MIT, MRT, and horizontal resistance was observed during re-insertion compared with the initial insertion, especially in the higher density cortical bone groups. However, there was no significant change in micromotion. While higher cortical bone density led to better primary stability, it also caused more abrasion to the miniscrews, thereby decreasing the primary stability during re-insertion.

Objective: The purpose of this study was to analyze stress distributions in the roots, periodontal ligaments (PDLs), and bones around cylindrical and tapered miniscrews inserted at different angles using a finite element analysis. Methods: We created a three-dimensional (3D) maxilla model of a dentition with extracted first premolars and used 2 types of miniscrews (tapered and cylindrical) with 1.45-mm diameters and 8-mm lengths. The miniscrews were inserted at 30°, 60°, and 90° angles with respect to the bone surface. A simulated horizontal orthodontic force of 2 N was applied to the miniscrew heads. Then, the stress distributions, magnitudes during miniscrew placement, and force applications were analyzed with a 3D finite element analysis. Results: Stresses were primarily absorbed by cortical bone. Moreover, very little stress was transmitted to the roots, PDLs, and cancellous bone. During cylindrical miniscrew insertion, the maximum von Mises stress increased as insertion angle decreased. Tapered miniscrews exhibited greater maximum von Mises stress than cylindrical miniscrews. During force application, maximum von Mises stresses increased in both groups as insertion angles decreased. Conclusions: For both cylindrical and tapered miniscrew designs, placement as perpendicular to the bone surface as possible is recommended to reduce stress in the surrounding bone.

Reduced food intake ability can restrict an individual's choice of foods and might have a significant impact on the individual's quality of life and mental health. The aim of this study was to evaluate the correlations between self-reported masticatory ability and oral health-related quality of life (OHRQOL) and psychological health. The study included 72 (26 men, 46 women) adults with a mean age of 26·4 ± 8·6 years. Each participant completed the key subjective food intake ability (KFIA) test for five key foods, the Korean version of the Oral Health Impact Profile-14 (OHIP-14K) and three questionnaires for measuring anxiety, depression and self-esteem. The participants were distributed into two groups by sex (a mean age of 23·9 ± 5·2 for men and 27·9 ± 9·8 for women) and by the median KFIA score. There were no significant differences in any of the variables according to sex. Thirty-two participants (12 men, 20 women) in the lower KFIA group had a higher total OHIP-14K (P < 0·001) and depression level (P < 0·05) than the 40 participants (14 men, 26 women) in the higher KFIA group. As the KFIA decreased, OHRQOL worsened (P < 0·001) and depression increased (P < 0·05). Participants with lower KFIA scores were more than 4·3 times as likely as to have a poor OHRQOL than the reference group (odds ratio, 4·348; 95% confidence interval, 1·554-12·170, P < 0·01). Lower subjective food intake ability is associated with a poor oral health-related quality of life and higher depression level.

Objective: To evaluate the stability of nonsurgical miniscrew-assisted rapid maxillary expansion (MARME) in young adults with a transverse maxillary deficiency. Materials and Methods: From a total of 69 adult patients who underwent MARME followed by orthodontic treatment with a straight-wire appliance, 20 patients (mean age, 20.9 ± 2.9 years) with follow-up records (mean, 30.2 ± 13.2 months) after debonding were selected. Posteroanterior cephalometric records and dental casts were obtained at the initial examination (T0), immediately after MARME removal (T1), immediately after debonding (T2), and at posttreatment follow-up (T3). Results: Suture separation was observed in 86.96% of subjects (60/69). An increase in the maxillary width (J-J; 1.92 mm) accounted for 43.34% of the total expansion with regard to the intermolar width (IMW) increase (4.43 mm; P < .001) at T2. The amounts of J-J and IMW posttreatment changes were −0.07 mm (P > .05) and −0.42 mm (P = .01), respectively, during retention. The postexpansion change in middle alveolus width increased with age (P < .05). The postexpansion change of interpremolar width (IPMW) was positively correlated with the amount of IPMW expansion (P < .05) but not with IMW. The changes of the clinical crown heights in the maxillary canines, first premolars, and first molars were not significant at each time point. Conclusions: Nonsurgical MARME can be a clinically acceptable and stable treatment modality for young adults with a transverse maxillary deficiency.

Objective: The aims of this study were to assess the direction and degree of lip-line cant in Korean adult orthodontic patients and to identify the effects of sex and age on changes in the cant severity. Methods: In this cross-sectional retrospective study, lip-line cant was measured in the frontal photographs of 585 Korean patients (92 men and 493 women) aged 18−48 years. The outcome variables (direction and degree of lip-line cant) were assessed in terms of predictor variables (sex, age, sagittal skeletal relationship, and menton deviation angle). Results: The direction of lip-line cant did not differ according to sex, age, or skeletal classification. Patients had 1.6 o of lip-line cant on average before orthodontic treatment. Middle-aged adults displayed a significant trend toward a lower degree of lip-line cant compared to younger adults (p < 0.01). Multiple linear regression analysis showed that the degree of lip-line cant was weakly negatively correlated with age (p < 0.001). Conclusions: While the direction of lip-line cant did not differ according to the parameters explored here, the degree of cant was correlated with age in adults, independent of menton deviation. Specifically, middle-aged adults tended to display significantly lower degrees of lip-line cant than did younger adults. [Korean J Orthod 2016;46(2):81-86]

Postoperative skeletal and dental changes were evaluated in patients with mandibular prognathism who underwent mandibular setback surgery using an intraoral vertical ramus osteotomy (IVRO) with and without presurgical orthodontic treatment.This retrospective cohort study included consecutive patients with skeletal Class III malocclusions who underwent IVRO. Patients treated with pre-orthodontic orthognathic surgery (POGS) were compared with patients treated with conventional surgery (CS) with presurgical orthodontics (control) using lateral cephalograms (taken preoperatively, 7 days postoperatively, and 12 months postoperatively). Predictor (group and timing), outcome (cephalometric measurements over time), and other (ie, baseline characteristics) variables were evaluated to determine the differences in postoperative horizontal and vertical positional changes of the mandible, such as point B. Baseline demographics were similar between the groups (N = 37; CS group, n = 17; POGS group, n = 20). The data were analyzed with an independent t test, the Mann-Whitney U test, the Fisher exact t test, Pearson correlation analysis, and simple linear regression analysis.The mean setback of the mandible at point B was similar, but the mandible of the POGS group, particularly the distal segment, moved superiorly during the postoperative period in conjunction with the removal of premature occlusal contacts (P.001). In the CS group, the mandible had significantly more backward movement 12 months after surgery compared with the POGS group (P.01). In the POGS group, horizontal and vertical postsurgical changes were linearly correlated with the amount of setback and vertical movement of the mandible.Mandibular setback surgery using IVRO without presurgical orthodontics leads to considerably different postoperative skeletal and dental changes compared with conventional treatment, with more superior movement being observed at point B during the 1-year postoperative period.

In this study, we aimed to assess the surface characteristics and the biomechanical stability of miniscrews with an anodic oxidized surface compared with machined surface miniscrews in beagle dogs.Self-drilled, titanium-aluminum-vanadium alloy miniscrews with an anodic oxidized surface (n = 48) or a machined surface (n = 48) were placed into the mandibles of 12 beagle dogs. The surface characteristics of both types of miniscrews were analyzed before implantation with scanning electron microscopy and atomic force microscopy. Insertion torque was measured during placement of all 96 miniscrews. Half of the implants in each group (24 specimens per subgroup) received 200 to 250 g of tensile force for 3-week or 12-week loading periods. Removal torque was measured in 12 specimens of each subgroup, and bone-implant contact and bone volume were quantified in the other 12 specimens of each subgroup.Atomic force microscopy measurements demonstrated that the anodic oxidized surface miniscrews had significantly higher roughness parameters than did the machined surface miniscrews (P 0.001). The 2 types of miniscrews were not significantly different in insertion and removal torque values or in bone-implant contacts and bone volumes, regardless of the loading period.Anodic oxidized miniscrews have different surface roughness profiles but no clinically significant superiority in biomechanical stability compared with machined surface miniscrews.

The creation of clinically patient-specific 3D-printed biomedical appliances that can withstand the physical stresses of the complex biological environment is an important objective. To that end, this study aimed to evaluate the efficacy of aminated nanodiamonds (A-NDs) as nanofillers in biological-grade acrylate-based 3D-printed materials. Solution-based mixing was used to incorporate 0.1 wt% purified nanodiamond (NDs) and A-NDs into UV-polymerized poly(methyl methacrylate) (PMMA). The ND and A-ND nanocomposites showed significantly lower water contact angles (p &lt, 0.001) and solubilities (p &lt, 0.05) compared to those of the control. Both nanocomposites showed markedly improved mechanical properties, with the A-ND-containing nanocomposite showing a statistically significant increase in the flexural strength (p &lt, 0.001), elastic modulus (p &lt, 0.01), and impact strength (p &lt, 0.001) compared to the control and ND-containing groups. The Vickers hardness and wear-resistance values of the A-ND-incorporated material were significantly higher (p &lt, 0.001) than those of the control and were comparable to the values observed for the ND-containing group. In addition, trueness analysis was used to verify that 3D-printed orthodontic brackets prepared with the A-ND- and ND-nanocomposites exhibited no significant differences in accuracy. Hence, we conclude that the successful incorporation of 0.1 wt% A-ND in UV-polymerized PMMA resin significantly improves the mechanical properties of the resin for the additive manufacturing of precisive 3D-printed biomedical appliances.

Odontogenic keratocysts (OKCs) are one of the most aggressive cysts in the oral and maxillofacial area because of their high recurrence rate and infiltrative behavior. In growing patients with OKCs, a radical treatment approach might cause numerous complications, including the disturbance of jaw growth and loss of the involved tooth. This case report describes successful comprehensive orthodontic treatment combined with marsupialization of the cyst in a young girl who exhibited an OKC with impacted teeth. The 10-year-old girl presented with an OKC extending from the mandibular symphysis through the left mandibular body, with ectopic impaction of the mandibular left canine and first premolar, as well as congenitally missing bilateral mandibular second premolars. Interestingly, spontaneous improvement of the positions of the ectopic impacted teeth, along with a reduction in the size of the cyst, occurred during marsupialization. The sequential use of removable and fixed appliances enabled orthodontic traction of the impacted teeth. The treatment outcome was stable at 2.5 years after the end of the treatment. We speculate that comprehensive orthodontic treatment combined with marsupialization can be an effective treatment strategy for patients with OKCs, especially when they are encountered in young, growing patients with impacted teeth.

Important aspects of orthognathic surgery are the effects of skeletal movement and changes in the position of the hyoid bone, tongue, soft palate, and dimensions of the pharyngeal airway. Our aims were to evaluate the 3-dimensional changes in the pharyngeal airway and in the position of the hyoid bone after mandibular setback in 30 patients who were diagnosed with mandibular prognathism and were treated by intraoral vertical ramus osteotomy (IVRO). Three-dimensional cone-beam computed tomographic (CT) images were obtained preoperatively, one month postoperatively, and one year postoperatively. The total pharyngeal volume decreased between the preoperative state and one month and one year afterwards. The hyoid bone had moved 2.0 mm posteriorly and 3.15 mm superiorly by one month postoperatively. The position of the hyoid bone was affected by changes in posterior and superior movement of the B point at one month (r = 0.44, p = 0.015 and R = 0.63, p = 0.000, respectively) and also by superior movement of the B point at one year (r = 0.57, p = −0.001). There was an advantageous relation between posterior positional changes in the B point (mandibular setback), and volumetric changes in the hypopharyngeal and total pharyngeal airway, so maxillofacial surgeons should consider the reduction in airway when planning excessive mandibular setback.

Objectives: To identify unique characteristics of the craniofacial complex and dental maturity in girls with central precocious puberty (CPP). Materials and Methods: This study included 34 Korean girls with idiopathic CPP (mean age, 8.6 ± .5 years) and 28 normal healthy girls of the same chronological age. An initial evaluation of the growth pattern of the craniofacial complex and dental maturity was conducted by analyzing lateral cephalometric and panoramic radiographs. Results: The mandibular ramus height (44.4 ± 4.1 mm) and total mandibular length (10.8 ± 4.3 mm) (P = .004 and .021, respectively) were greater and the lower anterior facial height was lesser (63.2 ± 2.4 mm) (P = .040) in the CPP group than in the reference group. In addition, the gonial angle (12.9 ± 6.1°; P = .045) and the mandibular plane angle (34.9 ± 4.8°; P = .012) were smaller in girls with CPP than in normal healthy girls. All the mandibular teeth were more mature in girls with CPP (P < .001). A strong positive correlation was observed between the mandibular tooth formation stages and the presence of CPP in girls (r = .756 to .957; P < .001). Conclusions: CPP had an effect on the anteroposterior growth of the mandible in the craniofacial complex and the rotation of the mandibular plane angle. Early maturation of the mandibular teeth was observed in girls with CPP.

Based on three-dimensional scanning and computer-aided design and computer-aided manufacturing (CAD/CAM) techniques, customized bracket systems are increasingly used. However, data remain limited regarding customized bracket design, characteristics, and stability. This study was undertaken to evaluate the design, bond strength, and residual adhesives of four different CAD/CAM customized brackets that were attached to human tooth specimens by indirect bonding. Thirty extracted human upper premolars were divided into five groups: Group 1, preadjusted self-ligating labial metal bracket; Group 2, lingual self-ligating metal injection molding customized bracket; Group 3, gold-casted lingual customized bracket; Group 4, labial self-ligating milled customized bracket; Group 5, labial customized resin base bracket. Except in Group 1, premolar specimens were scanned via model scanner, and the images were sent to each manufacturing company to fabricate customized brackets and transfer trays/jigs. Debonding force (DF; N) was measured by Instron universal testing machine and shear bond strength (SBS; MPa) was calculated via dividing DF by bonding area. Adhesive remnants were analyzed via stereo microscopic images. Group 2 (196.90±82.75 N) exhibited significantly higher DF than Group 1 (62.77±12.65 N); other groups exhibited similar DFs, compared with Group 1. No customized bracket groups exhibited significant differences in SBS, relative to Group 1 (6.73±1.36 MPa). However, SBS in Group 5 (11.46±7.22 MPa) was significantly higher than in Group 3 (3.58±2.14 MPa). Group 3 had significantly lower ARI scores than other groups (P

Objective. We investigated the suitability of intraoral-scan models for measuring tooth dimensions and the amount of crowding in patients with severe tooth crowding. Materials and Methods. Fifty-eight patients who had undergone intraoral scans for diagnosis were included. Cast models were divided into two groups depending on the amount of crowding, as determined by initial caliper-based measurements (mild crowding [MC] group: 4.5 mm). Twenty maxillary models and 20 mandibular models were used in this study. For the three types of models (i.e., IS digital model, C cast model, and CS digital model), the reproducibility and the precision of linear measurements were evaluated. Results. We found that linear measurements made using digital calipers on a plaster model and on the relevant software were reproducible. There was no significant difference in most linear measurements between digital models and the C model. There were differences in the amount of crowding (p<.05), although these were not clinically significant. There was no relationship between the precision of crowding in the three types of models and the severity of crowding. Conclusions. Digital models can be used for measuring crowding in both mild and severe crowding cases. However, crowding measured by digital models tends to be lesser than that measured by cast models, and this should be considered during clinical application.

Objective. The aim of this study was to evaluate the morphological characteristics of the palatal rugae in Korean subjects to determine whether the palatal rugae can be used as an appropriate reference area for three-dimensional digital model superimpositions. Materials and Methods. In total, 343 patients (110 men, 233 women; mean age, 25.6±8.2 years) who had a digital model taken at their initial visit were included, and the numbers and types of right and left palatal rugae were investigated according to the primary, secondary, and fragmentary rugae. Finally, the differences in the positions of the third primary ruga were investigated according to the presence of additional rugae posterior to the third primary ruga. Results. The number of primary palatal rugae ranged from one to six, with 43.5% of the subjects having three primary rugae and 36.1% having four primary rugae; there were no significant differences between sexes. Except for the fragment rugae, the numbers of primary and secondary rugae were not significantly different between the left and right sides. The third primary ruga was located more significantly anteriorly when there was an additional ruga posterior to the third primary ruga (P < 0.001). Conclusions. The numbers of the palatal rugae vary greatly among individuals, and this affects the anteroposterior position of the third primary ruga. When the third primary ruga is located anteriorly, care should be taken when using it as a reference area for superimposition with a digital model before and after orthodontic treatment.

Objective We evaluated whether the biological activity of the surface of titanium, when stored in an aqueous solution, in low vacuum, and under ambient conditions after ultraviolet light (UV) treatment is comparable to that of the surface immediately after UV treatment for 15 min and that after dielectric barrier discharge (DBD) plasma treatment for 15 min. Methods Grade IV titanium discs with machined surfaces were irradiated with UV and their surface properties were evaluated immediately and after storage for 28 days in distilled H 2 O (dH 2 O), a vacuum desiccator (31.325 kPa), and a sealed container under air. Their surface characteristics were evaluated by atomic force microscopy, X-ray diffraction, contact angle analysis, and X-ray photoelectron spectroscopy. Biological activities were determined by analyzing the albumin adsorption, MC3T3-E1 cell adhesion, and cytoskeleton development. Results Hydrophilicity of titanium surfaces stored in dH 2 O was comparable to that immediately after UV treatment and higher than that immediately after DBD plasma treatment ( P 0.001). Storage in dH 2 O and in low vacuum immediately after UV treatment prevented hydrocarbon contamination and maintained elevated amounts of titanium and oxygen. After 28 days, protein adsorption, cellular adhesion, and cytoskeletal development of MC3T3-E1 cells on the titanium surfaces stored in dH 2 O were significantly enhanced compared to those stored in low vacuum and under ambient conditions while being comparable to those immediately after UV and DBD plasma treatments. Significance UV treatment of the titanium implants followed by wet storage is useful for maintaining enhanced biological activity and overcoming biological aging during shelf storage.