Human umbilical cord/placenta mesenchymal stem cell conditioned medium attenuates intestinal fibrosis in vivo and in vitro.

BACKGROUND: A significant unmet need in inflammatory bowel disease is the lack of anti-fibrotic agents targeting intestinal fibrosis. This study aimed to investigate the anti-fibrogenic properties and mechanisms of the conditioned medium (CM) from human umbilical cord/placenta-derived mesenchymal stem cells (UC/PL-MSC-CM) in a murine intestinal fibrosis model and human primary intestinal myofibroblasts (HIMFs). METHODS: UC/PL-MSC-CM was concentrated 15-fold using a 3 kDa cut-off filter. C57BL/6 mice aged 7 weeks old were randomly assigned to one of four groups: (1) control, (2) dextran sulfate sodium (DSS), (3) DSS + CM (late-phase treatment), and (4) DSS + CM (early-phase treatment). Chronic DSS colitis and intestinal fibrosis was induced by three cycles of DSS administration. One DSS cycle consisted of 7 days of oral DSS administration (1.75%, 2%, and 2.5% DSS), followed by 14 days of drinking water. UC/PL-MSC-CM was intraperitoneally administered in the late phase (from day 50, 10 times) or early phase (from day 29, 10 times) of DSS cycles. HIMFs were treated with TGF-ß1 and co-treated with UC/PL-MSC-CM (10% of culture media) in the cellular model. RESULTS: In the animal study, UC/PL-MSC-CM reduced submucosa/muscularis propria thickness and collagen deposition, which improved intestinal fibrosis in chronic DSS colitis. The UC/PL-MSC-CM significantly reduced the expressions of procollagen1A1 and α-smooth muscle actin, which DSS significantly elevated. The anti-fibrogenic effect was more apparent in the UC-MSC-CM or early-phase treatment model. The UC/PL-MSC-CM reduced procollagen1A1, fibronectin, and α-smooth muscle actin expression in HIMFs in the cellular model. The UC/PL-MSC-CM downregulated fibrogenesis by suppressing RhoA, MRTF-A, and SRF expression. CONCLUSIONS: Human UC/PL-MSC-CM inhibits TGF-ß1-induced fibrogenic activation in HIMFs by blocking the Rho/MRTF/SRF pathway and chronic DSS colitis-induced intestinal fibrosis. Thus, it may be regarded as a novel candidate for stem cell-based therapy of intestinal fibrosis.

Can medication-related osteonecrosis of the jaw be attributed to specific microorganisms through oral microbiota analyses? A preliminary study.

BACKGROUND: Medication-related osteonecrosis of the jaw (MRONJ) can cause significant pain and loss of aesthetics and function if not treated properly. However, diagnosis still relies on detailed intraoral examinations and imaging. Prognosis varies even among patients with similar stages or conditions of MRONJ, emphasizing the need for a deeper understanding of its complex mechanisms. Thus, this study aimed to identify the oral microbiota of patients with MRONJ. METHODS: This single-center prospective cohort study included patients with confirmed MRONJ who visited the Department of Oral and Maxillofacial Surgery at Yonsei University Dental Hospital between 2021 and 2022. Oral swab samples were collected from the affected and unaffected sides of each patient. The composition and enumeration of the microbial communities were analyzed, and the diversity was compared to verify ecological changes in the groups using a next-generation sequencing-based 16S metagenomic analysis. A statistical analysis was performed using Wilcoxon signed-rank test with SPSS version 22, and values of P less than 0.05 were considered statistically significant. RESULTS: The final study sample included 12 patients. The mean age was 82.67 ± 5.73 (range, 72-90) years. Changes in microbial composition were observed at different taxonomic levels (phylum, genus, and species). The identified microorganisms were commonly associated with periodontitis, gingival disease, and endodontic infection, suggesting a multifactorial etiology of MRONJ. CONCLUSIONS: Although this study is based on a small number of cases, it shows that MRONJ is not caused by a specific microorganism but can rather be caused by a variety of factors. By addressing these findings in large-scale studies, the significance of oral microbiome in pathogenesis can be further elucidated and can facilitate the development of effective therapeutic interventions for patients with MRONJ.

Anterior open bite correction via molar intrusion: Diagnosis, advantages, and complications.

Anterior open bite can be effectively treated nonsurgically via molar intrusion. This technique, involving the intrusion of posterior teeth using temporary skeletal anchorage devices, prompts counterclockwise rotation of the mandible. This rotation not only corrects anterior open bite but also contributes to a decrease in anterior facial height, improvements in lip incompetency, and forward movement of the chin. For successful outcomes, temporary skeletal anchorage devices, installed on both the buccal and palatal sides, must deliver equivalent intrusion force to the maxillary teeth. Treatment planning should consider factors such as skeletal discrepancies, vertical excess, incisor exposure, and configuration of the occlusal plane. Clinicians are advised to closely monitor periodontal changes and consider overcorrection to ensure lasting stability and maintenance of incisal overlap post-treatment.

Platelet Membrane-Enclosed Bioorthogonal Catalysis for Combating Dental Caries.

Platelets have shown promise as a means to combat bacterial infections, fostering the development of innovative therapeutic approaches. However, several challenges persist, including cargo loading issues, limited efficacy against biofilms, and concerns regarding the impact of payloads on the platelet carriers. Here, human platelet membrane vesicles (h-PMVs) encapsulating supramolecular metal catalysts (SMCs) as "nanofactories" to convert prodrugs into antimicrobial compounds within close proximity to bacteria are introduced. Having established the feasibility and effectiveness of the SMCs within h-PMVs, referred to as the PLT-reactor, to activate pro-antibiotic drugs (pro-ciprofloxacin and pro-moxifloxacin) using model organisms (Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 25923), the investigation is subsequently extended to oral biofilms, with a particular emphasis on Streptococcus mutans 3065. This "bind and kill" strategy demonstrates the potent antimicrobial specificity of the PLT-reactor through localized antibiotic production. h-PMVs play a pivotal role by enabling precise targeting of pathogenic biofilms on natural teeth while minimizing potential hemolytic effects. The finding indicates that platelet membrane-cloaked surfaces exhibit robust, multifaceted, and pathogen-specific binding affinity with excellent biocompatibility, making them a promising alternative to antibody-based therapies for infectious diseases.

Surgical vs nonsurgical treatments in patients with anterior open-bite have similar effects in occlusal function: A 2-year follow-up study.

INTRODUCTION: This study aimed to investigate changes in bite force (BF) and occlusal contact area after anterior open-bite (AOB) treatment and compare the changes in surgical vs nonsurgical treatment. METHODS: This retrospective study included patients with AOB compared with normal occlusion. AOB was corrected by either intrusion of the maxillary molars (intrusion group, n = 19) or orthognathic surgery (surgery group, n = 37). The control group (n = 35) had a normal overbite relationship. Records of lateral cephalograms, BF, and occlusal contact area taken before (T0), immediately after (T1), and 2 years after (T2) orthodontic treatment were compared within and among the 3 groups. RESULTS: The open-bite group, including intrusion and surgery groups, had a lower BF and less occlusal contact area than the control group at T0 and T1 (P <0.001). However, there were no significant differences among the 3 groups at T2 (P >0.05). The intrusion and surgery groups showed no significant differences throughout the observation period extending from T0 to T2 (P >0.05). Although BF and occlusal contact area decreased at T1 compared with T0, they increased during retention and showed higher values at T2 than at T0. CONCLUSIONS: Treatment of AOB improved BF and occlusal contact area 2 years posttreatment. Orthognathic surgery and molar intrusion using orthodontic miniscrews can improve occlusal function similarly. Orthodontists can select either method depending on malocclusion severity and patient demand.

Three-dimensional evaluation of dentopalatal changes after rapid maxillary expansion in growing children.

INTRODUCTION: In growing children with transverse malocclusion problems, various types of rapid maxillary expanders (RMEs) have been effectively used in skeletal and dental expansions. We evaluated 3-dimensional dentopalatal changes in growing children who underwent maxillary expansion using RMEs and bonded RMEs. METHODS: We investigated dentopalatal changes in 20 patients treated with bonded RMEs, 19 with RMEs, and 38 control patients. Dental plaster models before and after expansion were scanned 3-dimensionally and superimposed to evaluate transverse expansion, expansion ratio, angular expansion, and palatal expansion height ratio. RESULTS: Using bonded RMEs, similar anterior and posterior dental expansions were achieved with an efficiency of 69%-76% (expansion ratio), and palatal soft-tissue expansion occurred more apically in the posterior area (palatal expansion height ratio, 1.00) than in the anterior area (palatal expansion height ratio, 0.64). Using RMEs, a larger posterior dental expansion was achieved, with an efficiency of 106%-117% (expansion ratio), than anterior dental expansion (55%-60%), and palatal soft-tissue expansion occurred more apically in the posterior area (palatal expansion height ratio, 0.99) than anterior area (palatal expansion height ratio, 0.23). CONCLUSIONS: Dental expansions in the anterior and posterior areas were similar using bonded RMEs, whereas the posterior dental expansions were larger than those of the anterior area using RMEs. The entire palatal soft-tissue slope expanded in the posterior area, whereas the occlusal part expanded in the anterior area using RMEs and bonded RMEs.

Treatment outcome comparison of Invisalign vs fixed appliance treatment in first premolar extraction patients.

INTRODUCTION: In this study, we compared the dentitional changes after Invisalign and conventional orthodontic treatment with 4 first premolar extractions. METHODS: This retrospective study included 57 patients whose orthodontic treatment involved the extraction of 4 first premolars because of bialveolar protrusion. A total of 27 patients were treated with Invisalign (mean age, 25.5 ± 5.2 years) and 30 patients with the fixed appliance (mean age, 24.4 ± 5.8 years). The angular and linear changes of the maxillary and mandibular central incisors, second premolars, first molars, and second molars were measured from the recordings on the basis of the lateral cephalograms taken before and after treatment. The angular changes of the canines and second premolars were measured using panoramic radiographs. RESULTS: The overbite and interincisal angle increased significantly in the Invisalign group compared with in the conventional fixed appliance group (P <0.05). The maxillary central incisors showed increased lingual tipping in the Invisalign group (P <0.05), whereas there was no statistically significant difference in the angular change of the mandibular incisors between groups (P >0.05). The maxillary first and second molars showed mesial tipping in the Invisalign group (P <0.05). The maxillary second premolars, first and second molars, and the mandibular second molars showed mesial movement in the Invisalign group (P <0.05). CONCLUSIONS: The Invisalign group showed more statistically significant lingual tipping of the maxillary central incisors, distal tipping of the maxillary canines, and mesial tipping of the maxillary first and second molars after maximum retraction of the anterior teeth compared with the fixed appliance group.

Association among craniofacial morphology, ethnicity, and risk of pediatric sleep-related breathing disorders: A multicenter study.

INTRODUCTION: Craniofacial morphology and ethnicity may be risk factors for sleep-related breathing disorder (SRBD) in children but have not yet been assessed in an international multicenter study. The objectives of this study were to assess the association among craniofacial features, self-reported ethnicity, and risk of SRBD in children undergoing orthodontic treatment. METHODS: Children aged 5-18 years who presented for orthodontic evaluation were enrolled in the United States, South Africa, South Korea, Saudi Arabia, and Japan. The risk of SRBD was defined as answering ≥0.33 positive responses to the Pediatric Sleep Questionnaire. Craniofacial features included measurements in sagittal and vertical dimensions to evaluate the cranial base, maxillomandibular and dental relationships, and nasopharyngeal airway dimensions. Logistic regression was performed to assess the association among craniofacial features, ethnicity, age, body mass index, and risk of SRBD. RESULTS: Data were obtained from 602 patients from 5 sites. A total of 76 patients (12.6%) had a risk of SRBD. The mean age was 12.5 years. Male gender (odds ratio [OR], 1.9; 95% confidence interval [CI], 1.0-3.4; P = 0.041), Middle Eastern ethnicity (OR, 10.2; 95% CI, 4.1-25.4; P = 0.001), body mass index (OR, 1.1; 95% CI, 1.04-1.10; P = 0.001), gonial angle (OR, 0.91; 95% CI, 0.85-0.98; P = 0.011), and inferiorly positioned hyoid (OR, 1.1; 95% CI, 1.0-1.2; P = 0.002) were significantly associated with the risk of SRBD. CONCLUSIONS: In an ambidirectional cohort study across 5 sites, male gender, Middle Eastern ethnicity, body mass index, gonial angle, and inferiorly positioned hyoid were associated with the risk of SRBD in children undergoing orthodontic treatment.

Three-dimensional evaluation of a virtual setup considering the roots and alveolar bone in molar distalization cases.

We aimed to evaluate root parallelism and the dehiscence or fenestrations of virtual teeth setup using roots isolated from cone beam computed tomography (CBCT) images. Sixteen patients undergoing non-extraction orthodontic treatment with molar distalization were selected. Composite teeth were created by merging CBCT-isolated roots with intraoral scan-derived crowns. Three setups were performed sequentially: crown setup considering only the crowns, root setup-1 considering root alignment, and root setup-2 considering the roots and surrounding alveolar bone. We evaluated the parallelism and exposure of the roots and compared the American Board of Orthodontics Objective Grading System (ABO-OGS) scores using three-dimensionally printed models among the setups. The mean angulation differences between adjacent teeth in root setups-1 and -2 were significantly smaller than in the crown setup, except for some posterior teeth (p < 0.05). The amount of root exposure was significantly smaller in root setup-2 compared to crown setup and root setup-1 except when the mean exposure was less than 0.6 mm (p < 0.05). There was no significant difference in ABO-OGS scores among the setups. Thus, virtual setup considering the roots and alveolar bone can improve root parallelism and reduce the risk of root exposure without compromising occlusion quality.

Pattern of lip retraction according to the presence of lip incompetence in patients with Class II malocclusion.

Objective: The aim of this retrospective study was to compare changes in hard tissue and soft tissue after the four first premolars were extracted with anterior teeth retraction according to the presence or absence of lip incompetence. Methods: Patients who underwent the four first premolars were extracted with anterior teeth retraction were divided into competent (n = 20) and incompetent lip (n = 20) groups. Cephalometric measurements for hard tissue and soft tissue changes were performed pre-treatment and post-treatment. Results: In the competent group, the upper and lower lips retreated by 2.88 mm and 4.28 mm, respectively, and in the incompetent group by 4.13 mm and 5.57 mm, respectively; the differences between the two groups were significant (p < 0.05). A strong positive correlation between retraction of the upper lip and upper incisors was observed in both groups (p < 0.05), whereas a correlation between retraction of the lower lip and lower incisors was only found in the incompetent group. A simple linear regression analysis showed that the pattern of lip retraction following the retraction of the anterior teeth was more predictable in the incompetent group than in the competent group. Conclusions: These findings suggest that the initial evaluation of lip incompetence in patients with skeletal Class II is essential for the accurate prediction of the soft tissue changes following retraction of the anterior teeth in premolar extraction treatment. Therefore, sufficient explanation should be provided during patient consultations.

Correlation of masticatory muscle activity and occlusal function with craniofacial morphology: a prospective cohort study.

OBJECTIVES: Masticatory function, including masticatory muscle activity and occlusal function, can be affected by craniofacial morphology. This study aimed to investigate the relationship between craniofacial morphology and masticatory function in participants who had completed orthodontic treatment at least two years before and had stable occlusion. MATERIALS AND METHODS: Fourty-two healthy participants were prospectively enrolled and divided into three vertical cephalometric groups according to the mandibular plane angle. Masticatory muscle activity (MMA) in the masseter and anterior temporalis muscles was assessed using surface electromyography. The occlusal contact area (OCA) and occlusal force (OF), defined as occlusal function in this study, were evaluated using occlusal pressure mapping system. Masticatory muscle efficiency (MME) was calculated by dividing MMA by OF. The craniofacial morphology was analyzed using a lateral cephalogram. The masticatory function was compared using one-way analysis of variance. Pearson correlations were used to assess relationships between craniofacial morphology and masticatory function. RESULTS: The hypodivergent group had the lowest MMAand the highest MME in the masseter (167.32 ± 74.92 µV and 0.14 ± 0.06 µV/N, respectively) and anterior temporalis muscles (0.18 ± 0.08 µV/N, p < 0.05). MMA in the masseter showed a positive relationship with mandibular plane angle (r = 0.358), whereas OCA (r = -0.422) and OF (r = -0.383) demonstrated a negative relationship (p < 0.05). The anterior temporalis muscle activity negatively correlated with ramus height (r = -0.364, p < 0.05). CONCLUSIONS: Vertical craniofacial morphology was related to masticatory function. Hypodivergent individuals may have low MMA and high occlusal function, resulting in good masticatory muscle efficiency. CLINICAL RELEVANCE: Hypodivergent individuals require careful consideration in orthodontic diagnosis and prosthetic treatment planning.

Changes in condylar position during orthodontic treatment depending on the amount of incisor retraction: a cone-beam computed tomography study.

OBJECTIVES: Orthodontic treatment may be associated with temporomandibular disorders through changes in the condylar position. This study aimed to evaluate changes in the condylar position among different amounts of maxillary incisor retraction during orthodontic treatment using cone-beam computed tomography images. MATERIALS AND METHODS: Fifty-four participants were enrolled and divided into minimal (n = 14), moderate (n = 20), and maximal (n = 20) retraction groups based on the amount of incisor retraction (< 1, 1-6, and > 6 mm, respectively). Changes in condylar position before (T0) and after (T1) orthodontic treatment were assessed for the superior, anterior, posterior, and medial joint spaces (SJS, AJS, PJS, and MJS, respectively). Changes in joint spaces were compared between T0 and T1 in each group using paired t-tests and among the three groups using analysis of variance. RESULTS: Anterior movement of the condyle was observed in the maximal retraction group with a 0.2 mm decrease in ΔAJS and a 0.2 mm increase in ΔPJS, significantly greater than those in the minimal retraction group. The AJS and PJS showed statistically significant differences between T0 and T1 (P < 0.05) in the maximal retraction group. CONCLUSIONS: The condyle may show a statistically significant but clinically insignificant forward movement in the maximal incisor retraction group, whereas it was relatively stable in the minimal and moderate incisor retraction groups. CLINICAL RELEVANCE: More attention should be paid to the signs and symptoms of the condyle in patients with excessive incisor retraction during orthodontic treatment.

Factors influencing the successful eruption of the maxillary third molar after extraction of the maxillary second molar.

INTRODUCTION: This study evaluated the occlusal status of the maxillary third molars that erupted spontaneously after extraction of the maxillary second molars and investigated the factors that influenced the occlusal status of the maxillary third molars. METHODS: We assessed 136 maxillary third molars in 87 patients. Alignment, marginal ridge discrepancy, occlusal contact, interproximal contact, and buccal overjet were used to score the occlusal status. Occlusal status was classified as good (G group), acceptable (A group), and poor (P group) for the maxillary third molar at its full eruption (T1). The Nolla's stage, long axis angle, the vertical and horizontal position of the maxillary third molar, and the maxillary tuberosity space were assessed at the time of maxillary second molar extraction (T0) and T1 to identify factors influencing the eruption of the maxillary third molar. RESULTS: G, A, and P groups comprised 47.8%, 17.6,% and 34.6% of the sample, respectively. Age was the lowest in the G group at both T0 and T1. The maxillary tuberosity space at T1 and the amount of the change of maxillary tuberosity space were the largest in the G group. There was a significant difference in the distribution of the Nolla's stage at T0. The proportions of the G group were 60.0% in stage 4, 46.8% in stages 5 and 6, 70.4% in stage 7, and 15.0% in stages 8-10. According to multiple logistic regression analysis, stages 8-10 for the maxillary third molar at T0 and the amount of the change of maxillary tuberosity were negatively associated with the G group. CONCLUSIONS: Good-to-acceptable occlusion was seen in 65.4% of the maxillary third molars after maxillary second molar extraction. Insufficient increase in the maxillary tuberosity space and Nolla stage 8 or higher at T0 negatively influenced the maxillary third molar eruption.

An Endodontic Forecasting Model Based on the Analysis of Preoperative Dental Radiographs: A Pilot Study on an Endodontic Predictive Deep Neural Network.

INTRODUCTION: This study aimed to evaluate the use of deep convolutional neural network (DCNN) algorithms to detect clinical features and predict the three-year outcome of endodontic treatment on preoperative periapical radiographs. METHODS: A database of single-root premolars that received endodontic treatment or retreatment by endodontists with presence of three-year outcome was prepared (n = 598). We constructed a 17-layered DCNN with a self-attention layer (Periapical Radiograph Explanatory System with Self-Attention Network [PRESSAN-17]), and the model was trained, validated, and tested to 1) detect 7 clinical features, that is, full coverage restoration, presence of proximal teeth, coronal defect, root rest, canal visibility, previous root filling, and periapical radiolucency and 2) predict the three-year endodontic prognosis by analyzing preoperative periapical radiographs as an input. During the prognostication test, a conventional DCNN without a self-attention layer (residual neural network [RESNET]-18) was tested for comparison. Accuracy and area under the receiver-operating-characteristic curve were mainly evaluated for performance comparison. Gradient-weighted class activation mapping was used to visualize weighted heatmaps. RESULTS: PRESSAN-17 detected full coverage restoration (area under the receiver-operating-characteristic curve = 0.975), presence of proximal teeth (0.866), coronal defect (0.672), root rest (0.989), previous root filling (0.879), and periapical radiolucency (0.690) significantly, compared to the no-information rate (P < .05). Comparing the mean accuracy of 5-fold validation of 2 models, PRESSAN-17 (67.0%) showed a significant difference to RESNET-18 (63.4%, P < .05). Also, the area under average receiver-operating-characteristic of PRESSAN-17 was 0.638, which was significantly different compared to the no-information rate. Gradient-weighted class activation mapping demonstrated that PRESSAN-17 correctly identified clinical features. CONCLUSIONS: Deep convolutional neural networks can detect several clinical features in periapical radiographs accurately. Based on our findings, well-developed artificial intelligence can support clinical decisions related to endodontic treatments in dentists.

SiO-induced thermal instability and interplay between graphite and SiO in graphite/SiO composite anode.

Silicon monoxide (SiO), which exhibits better cyclability compared to silicon while delivering higher capacity than that of graphite, is an adequate material for the development of lithium-ion batteries (LIBs) having higher energy densities. However, incorporating silicon-based materials including SiO into stable graphite anode inevitably degrades not only cycle life but also calendar life of LIBs, while little is known about their aging mechanisms. Here, SiO-induced thermal instability of the graphite/SiO composite anode is investigated. We reveal that under thermal exposure, SiO accelerates the loss of lithium inventory and concomitantly facilitates the lithium de-intercalation from graphite. This self-discharge phenomenon, which is weakly observed in the graphite anode without SiO, is the result of preferential parasitic reaction on the SiO interface and spontaneous electron and lithium-ion migration to equilibrate the electron energy imbalance between graphite and SiO. Understanding this underlying electron-level interplay between graphite and SiO in the composite anode will contribute toward improving shelf life of SiO-containing LIBs in actual operating conditions.

Three-dimensional soft tissue landmark detection with marching cube algorithm.

Current method of analyzing three-dimensional soft tissue data, especially in the frontal view, is subjective and has poor reliability. To overcome this limitation, the present study aimed to introduce a new method of analyzing soft tissue data reconstructed by marching cube algorithm (Program S) and compare it with a commercially available program (Program A). Cone-beam computed tomography images of 42 patients were included. Two orthodontists digitized six landmarks (pronasale, columella, upper and lower lip, right and left cheek) twice using both programs in two-week intervals, and the reliability was compared. Furthermore, computer-calculated point (CC point) was developed to evaluate whether human error could be reduced. The results showed that the intra- and inter-examiner reliability of Program S (99.7-100% and 99.9-100%, respectively) were higher than that of Program A (64.0-99.9% and 76.1-99.9%, respectively). Moreover, the inter-examiner difference of coordinate values and distances for all six landmarks in Program S was lower than Program A. Lastly, CC point was provided as a consistent single point. Therefore, it was validated that this new methodology can increase the intra- and inter-examiner reliability of soft tissue landmark digitation and CC point can be used as a landmark to reduce human error.

Changes in masticatory performance during the retention period following 4-premolar extraction and non-extraction orthodontic treatment.

OBJECTIVES: To evaluate changes in masticatory performance (MP) during the retention period after extraction and non-extraction treatment and compare it with MP in individuals with normal occlusion. MATERIALS AND METHODS: Adult patients who had completed orthodontic fixed appliance treatment comprised the extraction and non-extraction treatment groups, and those with normal occlusion comprised the control group. Their mixing ability (MA), maximum bite force (MBF), and occlusal contact area (OCA) were recorded immediately after the fixed appliance was removed and at 1 month, 6 months, and 1 year post-treatment. The MA was measured via the two-color chewing gum MA test using ViewGum software, and the MBF and OCA were measured using Dental Prescale II system. RESULTS: MA immediately after orthodontic treatment was lower than that in the normal group but showed a time-dependent gradual increase during a 1-year retention period (P < 0.01). The MA at 1 month post-treatment was not significantly different between the three groups (P > 0.05). The MA revealed a significant correlation with the MBF and OCA (P < 0.01). CONCLUSIONS: The MP immediately after orthodontic treatment was lower than that in the normal group but increased gradually, with levels comparable to those of the normal occlusion group at 1 month post-treatment. Further, extraction did not affect the recovery of the MP after orthodontic treatment. CLINICAL RELEVANCE: No other study has evaluated the changes in MP during the retention period after orthodontic treatment. The findings show that compared with MBF and OCA, the patients' MP improved faster to levels found in normal occlusion.

Evaluation of the dimensional alternation of the alveolar bone in patients with a congenitally missing mandibular lateral incisor using cone-beam computed tomography.

INTRODUCTION: The alveolar bone is an essential consideration when planning treatment for patients with tooth agenesis. This study evaluated the changes in the alveolar bone and adjacent teeth in patients with a congenitally missing mandibular lateral incisor using cone-beam computed tomography. METHODS: Twenty-three nonorthodontically treated adults with a unilateral congenitally missing mandibular lateral incisor were the missing group (M group). The control group (C group) consisted of 23 nonorthodontically treated adults with normal occlusion and no missing teeth. First, the difference in the arch perimeter between the groups was compared at the cementoenamel junction (CEJ) level and the root apex (RA) level. Next, the root divergence of the anterior teeth in the M group was observed. Finally, the alveolar bone thickness ratio was compared between the M and C groups at different vertical levels. RESULTS: The arch perimeter was significantly decreased in the M group at the CEJ and RA levels (P <0.05). Root divergence was observed adjacent to the missing site (P <0.0001). There were a reduction in total and cancellous cortical alveolar bone thickness (ABT) ratios at the 3-, 6-, and 9-mm positions (P <0.05). The buccal cortical ABT ratios decreased at the 3-and 6-mm positions. The lingual ABT ratio increased at the 9-mm position (P <0.05). CONCLUSIONS: The congenitally missing mandibular lateral incisor caused a reduction in the arch perimeter in the CEJ area and the RA area. The root divergences were observed in the teeth adjacent to the missing areas. A significant decrease in the buccal cortical bone and cancellous bone was observed in the missing area.

Evaluation of miniscrew-assisted rapid palatal expansion success by comparing width of circummaxillary sutures before expansion in adult male patients.

OBJECTIVES: To investigate the relationship between circummaxillary sutures and miniscrew-assisted rapid palatal expansion (MARPE) success in adult male patients and to evaluate the correlation between the width of the sutures and the maxilla expansion ratio. MATERIALS AND METHODS: This retrospective study comprised 40 adult male patients treated with MARPE divided into a separation group (N = 20, mean age, 21.9 years) consisting of subjects with midpalatal suture opening and a nonseparation group (N = 20, mean age, 21.7 years) consisting of subjects with no midpalatal suture opening. Cone-beam computed tomography images were obtained before MARPE expansion for both groups and after expansion for the separation group. Vertical and horizontal skeletal relationships, palate length, and widths of 10 circummaxillary sutures before expansion were compared. The correlation between maxilla expansion ratio (jackscrew expansion to maxillary expansion ratio) and circummaxillary suture widths was also analyzed in the separation group. RESULTS: There were no significant differences in age, vertical and horizontal skeletal relationships, and palate length between the two groups. Zygomaticomaxillary, pterygomaxillary, midpalatal, and transverse palatine sutures showed significantly greater width in the separation group (P < .05). The zygomaticomaxillary suture showed the greatest difference (Δ = 0.36 mm) between the groups. The zygomaticomaxillary and pterygomaxillary sutures showed significant positive correlation with the maxilla expansion ratio (P < .01). CONCLUSIONS: In adult male patients, greater circummaxillary suture widths before MARPE expansion, especially zygomaticomaxillary and pterygomaxillary sutures, resulted in a better chance of successful suture separation and more maxillary expansion.