Three dimensional quantitative study of soft tissue changes in nasolabial folds after orthodontic treatment in female adults.

BACKGROUND: With the popularity of medical aesthetic programs, some female adults who will or are undergoing orthodontic treatment often wonder whether orthodontic treatment has adverse effects on the nasolabial folds (NLFs). The aims of the study were to investigate any potential changes in the NLFs and associated peripheral soft tissues after orthodontic treatment of female adults. METHODS: This study compared changes in the NLFs and peripheral soft tissues in female adults undergoing orthodontic treatment using the 3dMD Face system (3dMD, Atlanta, Ga). A total of 52 adult female patient cases (24 teeth extraction, 28 non-teeth extraction) were included to evaluate the effects of different orthodontic treatment regimens on the NLFs and peripheral soft tissues. RESULTS: In the NLFs area, the landmarks of the extraction group were all significantly negatively changed (P < 0.001; the NLF2s average value was - 0.72 mm), and the upper and middle parts of the landmarks were negatively changed in the non-extraction group (P < 0.05; the NLF2s average value was - 0.22 mm). Compared to the non-extraction group, the negative changes in the extraction group were more pronounced (P < 0.005). In the lip region, all landmarks in the extraction group were negative changes (P < 0.05; upper lip (ULP) = - 0.93 mm, lower lip (LLP) = - 1.46 mm), and most landmarks in the non-extraction group were positive changes (P < 0.01; ULP = 0.55 mm). In the cheek area, the left and right buccal of the extraction and non-extraction groups were all negatively changed (P < 0.05), and there was no significant difference between the two groups. CONCLUSION: After orthodontic treatment, the NLFs showed negative changes, which were more obvious in the extraction group. The lip soft tissue had a negative change in the extraction group and a positive change in the non-extraction group, indicating that orthodontic treatment affected the soft tissue around the nasolabial sulcus, and that tooth extraction would lead to more negative changes.

Clinical characteristics and risk factors of major oral ulcers in the mandibular retromolar region in children.

OBJECTIVES: To describe the characteristics of major aphthous ulcers (MjOU) in children and analyze its potential risk factors. MATERIALS AND METHODS: Data were collected from the National Clinical Research Center for Oral Diseases of China between 2012 and 2017. Children younger than 15 years old, who had a giant mucosa ulcer (≥ 1 cm in diameter) and met the diagnostic criteria for MjOU were included in this study. Differences were compared between two subgroups of patients based on the location of the ulcerous lesions. A measurement of ratio (TBR) between the length of the mandibular second molar tooth germ and the height of the mandible was performed in children with MjOU lesions located in the mandibular retromolar pad region (MjOU-P) and their age- and sex-matched controls. RESULTS: A total of 1067 children were diagnosed with oral ulcers during the study period, of which 125 (11.7%, 95% CI: 9.8%-13.7%) met the diagnostic criteria for MjOU. More than half (n = 64, 51.2%) of the MjOU cases were MjOU-P, which had a male predilection (n = 52, 81.3%) with a significant majority at 7 to 9 years of age (n = 43, 67.2%). In comparison to the MjOU located in other regions, MjOU-P lasted longer in duration and had more comorbidities. Logistic regression analysis showed that MjOU-P was statistically significantly associated with TBR controlling age and gender. CONCLUSIONS: MjOU-P is a predominant form of MjOU in children and is a distinct subgroup of major ulcers that is likely associated with the development of the mandibular second molars. CLINICAL RELEVANCE: This study is the first to describe the demographic and clinical features of MjOU in children, which may facilitate the identification and treatment of these patients.

Edge smoothness enhancement in DMD scanning lithography system based on a wobulation technique.

The resolution of digital micro-mirror device (DMD) scanning lithography is limited in the transverse direction (the scanning direction is vertical) as a result of the compacted size of the DMD micro-mirror and the low magnification of the projection lens. Above-stated restrictions lead to an unsatisfactory saw-tooth edge (size ~one DMD pixel) after the lithography process within all directions except for the scanning orientation. In order to smooth the edge, an optimized sub-pattern construction method, described as the combination of wobulation techniques and the continuous scanning lithography process, is proposed. Afterward, lithography experiments were implemented by introducing the wobulation techniques within the DMD scanning lithography system. The experimental results show that the saw-tooth edge is reduced to nearly 0.5 pixel size after 1/2 pixel dislocation superposition exposure, and is even scaled down to less than 0.1 pixel after 1/4 pixel dislocation superposition exposure. At this point, the edge of the lithography pattern is appropriately smoothed. The effectiveness of the above-mentioned method that improves the edge smoothness of the lithography pattern is demonstrated.

Comparison between basal arch width in normal occlusions and class â ¡ malocclusions by using cone-beam computed tomography.

Objective: The purpose of this research was to investigate the measurements of maxillary and mandibular basal arch width in male and female with normal occlusion, and to compare dental arch width difference between normal occlusion and ClassⅡ malocclusion groups could be helpful in orthodontic diagnosis and treatment planning. Methods: Cone-beam computed tomography (CBCT) images from 133 individuals (76 males and 57 females) with normal occlusion and 64 (25 males and 39 females) with skeletal Class II malocclusions were evaluated. The distances between canines, first molars (basal arch widths: BAW) and second molars were measured from CRs (center of resistance) of the teeth and the projection of first molars on buccal bones (WALA distance) were measured. Results: There were significant differences in male and female maxillary and mandibular dental transverse widths. The normal range of the maxilla and mandible basal bone widths differences were -2 mm-2 mm (-0.05 ± 2.17 mm). The normal occlusion and Class Ⅱ groups exhibited significant differences in the width of the intercanine and first molars. Sella-nasion-A point angle (SNA) and Sella-nasion-B point angle (SNB) in the Class Ⅱ male group were positively correlated with the width between the maxillary canines. For individuals with normal occlusions, the width of the mandible at the second molar was greater than that of the maxilla, so more attention should be paid to the width of the second molar when considering clinical treatment. Conclusion: Measuring the width of the maxilla and mandible basal bones from the resistance center of the first molar was a feasible and repeatable method can be used in clinical practice. The data could serve as a reference for orthodontic treatment planning. More consideration should be paid to the horizontal dental problems of the treatment plan for Class Ⅱ patients. And the width of the mandible at the second molar was greater than that of the maxilla, so more attention should be paid during treatment.

Evaluation of alveolar bone morphology of incisors with different sagittal skeletal facial types by cone beam computed tomography: A retrospective study.

Background: Safe orthodontic tooth movement should be performed within the alveolar bone. The purpose of this study was to evaluate the morphology of the alveolar bone of incisors. Materials and methods: This retrospective study included pretreatment cone beam computed tomography of 120 patients with malocclusion. Patients were divided into 4 groups (Class I, Class II division 1, Class II division 2 and Class III) according to the subspinale-nasion-supramental (ANB) angle and occlusal relationship. The sagittal root positions, anterior and posterior root-cortical bone angles (AR-CA and PR-CA), root-crown ratios (RCR) and alveolar bone thickness were evaluated. Results: The sagittal root positions were mainly positioned against the labial cortical plate in the maxillary incisors of the Class II division 2 group and engaged by both the labial and palatal cortical plates in the mandibular incisors of the Class III group. The AR-CA was lower than that in the other groups (P < 0.01) in the maxillary incisors of the Class II division 2 group, and the AR-CA and PR-CA were lower than those in the other groups (P < 0.01) in the mandibular incisors of the Class III group. The alveolar thickness showed no significant difference between the Class II division 1 group and the Class I group (P > 0.05), the middle and lower anterior alveolar thickness (LAAT and MAAT) were lower than those in other groups (P < 0.01) in the maxillary incisors of the Class II division 2 group, and the alveolar thickness at the measurement sites of the middle and lower line were lower than those in other groups (P < 0.01) in the mandibular incisors of the Class III group. The RCR had a moderate positive correlation with the LAAT. Conclusion: Based on several limitations, this study found that maxillary incisor roots were at risk of penetrating the alveolar bone of Class II division 2 patients, and mandibular incisors may have a relatively small range of safe movement on both the labial and lingual sides of Class III patients during orthodontic treatment.

Lignocellulose utilization and bacterial communities of millet straw based mushroom (Agaricus bisporus) production.

Agaricus bisporus is in general cultivated on wheat and rice straw in China. However, millet straw is a potential alternative resource for Agaricus bisporus cultivation, but this has hardly been studied. In the present study, the feasibility of millet straw based mushroom production was analyzed by three successive trials. Mature compost demonstrated high quality with total nitrogen, pH, and C/N ratio of 2.0%, 7.5, and 18:1 respectively, which was suitable for mushroom mycelia growth. During composting, 47-50% of cellulose, 63-65% of hemicellulose, and 8-17% lignin were degraded, while 22-27% of cellulose, 14-16% of hemicellulose, and 15-21% of lignin were consumed by A. bisporus mycelia during cultivation. The highest FPUase and CMCase were observed during mushroom flushes. Endo-xylanase had the key role in hemicellulose degradation with high enzyme activity during cultivation stages. Laccase participated in lignin degradation with the highest enzyme activity in Pinning stage followed by a sharp decline at the first flush. Yield was up to 20 kg/m2, as this is similar to growth on wheat straw, this shows that millet straw is an effective resource for mushroom cultivation. Actinobacteria, Bacteroidetes, Chloroflexi, Deinococcus-Thermus, Firmicutes, and Proteobacteria were the dominant phyla, based on 16S rRNA gene sequencing during composting. The key environmental factors dominating bacterial communities of the samples were determined to be pH value, cellulose content, and hemicellulose content for prewetting and premixed phase of basic mixture (P0); moisture content for phase I (PI); and nitrogen content, lignin content, and ash content for phase II (PII), respectively.