Pigment Index Research Articles

Impact of gingival pigmentation on laypersons’ perception of smile aesthetics: an observational study

Aim: The study aims to assess laypersons’ perceptions of smile aesthetics before and after gingival depigmentation and to correlate these perceptions with the degree of gingival pigmentation. Methods: The retrospective observational study examined individuals who received gingival depigmentation following orthodontic treatment between 2019 and 2024. Fifteen records were selected based on the inclusion and exclusion criteria. The pre- and post-depigmentation frontal smile photos were standardized, included into a Google Form, and distributed to 40 laypeople for the assessment of smile aesthetics. The laypeople evaluated the attractiveness of smiles using a 10-point Likert scale. Experienced periodontists classified the gingival pigmentation utilizing the oral pigmentation index (OPI). The differences between the pre- and post-treatment OPI scores and smile esthetic scores were assessed using Wilcoxon signed-rank test. Spearman correlation was used to evaluate the association between smile scores and OPI scores. The intraclass correlation coefficient (ICC) was employed to evaluate the inter-rater reliability of the smile ratings and OPI scores. The statistical significance was established at p ≤ 0.05. Results: The average OPI scores before depigmentation were 2.67 ± 0.49; however, following depigmentation, the scores significantly declined to an average of 0.33 ± 0.5 (p < 0.001). The mean smile aesthetic score pre-depigmentation was 6.72 ± 0.32, whereas after depigmentation the scores significantly improved to 7.91 ± 0.18 (p = 0.001). Spearman correlation indicated a statistically significant negative association between smile aesthetics scores and OPI scores (r = –0.76). ICC indicated excellent inter-rater reliability for the OPI (0.923) and good reliability for smile esthetic scores (0.756). Conclusions: The study found that gingival de-pigmentation procedures improve the OPI scores and laypeople perceive gingival hyperpigmentation unattractive. While gingival depigmentation is not mandatory, it may be recommended for individuals seeking cosmetic smile enhancements post-orthodontic therapy to improve the overall patient satisfaction.

Detection of Rice Leaf Folder in Paddy Fields Based on Unmanned Aerial Vehicle-Based Hyperspectral Images

Pest infestations significantly impact rice production and threaten food security. Remote sensing offers a vital tool for the non-destructive, rapid detection of rice pests. Existing studies often focus on laboratory conditions at the leaf level, limiting their applicability for precise pesticide application. Therefore, this study aimed to develop a method for detecting rice pests (rice leaf folders) in paddy fields based on unmanned aerial vehicle (UAV) hyperspectral data. Firstly, a UAV imaging system collected hyperspectral images of rice plants in both the jointing and heading stages. A total of 222 field plots for investigating rice leaf folders was established during these two periods. Secondly, 23 vegetation indices were calculated as candidates for identifying rice pests. Then, hyperspectral data and field investigation data from the jointing stage were used to construct a machine learning (extreme gradient boosting, XGBoost) algorithm for detecting rice pests. The results showed that the XGBoost model exhibited the best performance when eight vegetation indices were considered as the selected input features for model construction: the Red-edge Normalized Difference Vegetation Index (red-edge NDVI), Structure Insensitive Pigment Index (SIPI), Enhanced Vegetation Index (EVI), Atmospherically Resistant Vegetation Index (ARVI), Soil-Adjusted Vegetation Index (SAVI), Red-edge Chlorophyll Index (CIred-edge), Pigment-Specific Simple Ratio680 (PSSR680), and Carotenoid Reflectance Index700 (CPI700). The training and testing accuracies reached 87.46% and 86%, respectively. Furthermore, the heading stage application confirmed the model’s feasibility. Thus, the XGBoost model with input features of eight vegetation indices provides an effective and reliable method for detecting rice leaf folders, supporting real-time, precise pesticide use in rice cultivation.

Effect of diode laser on oral pigmentation, pain, and wound healing in patients with gingival hyperpigmentation: a meta-analysis.

Diode laser represents a practical clinical strategy for treating gingival hyperpigmentation. However, its effectiveness remains controversial. The aim of this meta-analysis was to evaluate the quantitative effects of diode laser therapy on gingival hyperpigmentation. PubMed, Embase, Web of Science, and Cochrane Library were systematically searched for the use of diode laser in gingival hyperpigmentation. The primary outcomes assessed were the Dummett-Gupta Oral Pigmentation Index (DOPI), visual analog scale pain scores, and the Wound Healing Index (WHI) for overall evaluation. The I2 index was calculated to identify heterogeneity, and sensitivity analyses were performed to identify sources of heterogeneity. Funnel plots and the Egger test were utilized to evaluate publication bias. Thirteen randomized controlled trials involving a total of 233 participants were included in the study. The analysis demonstrated that diode laser had a significant effect on DOPI (standard mean difference [SMD] = -0.245, 95% CI -0.451 to -0.040, P = .019) and pain (SMD = -0.809, 95% CI -1.332 to -0.285, P = .002), with no significant effect on WHI (SMD = -0.224, 95% CI -1.100 to 0.653, P = .617). Despite the significant heterogeneity in VAS and WHI indicated by the I2 index statistic, the sensitivity analyses' results demonstrated the main findings' reliability. While no significant publication bias was detected for DOPI and WHI, the pain results exhibited notable publication bias. The study demonstrated that diode laser prolongs gingival repigmentation time and reduces pain compared to other treatments. However, efficacy in wound healing was not significantly affected.

Contrasting Alleles of OsNRT1.1b Fostering Potential in Improving Nitrogen Use Efficiency in Rice.

Nitrogen use efficiency (NUE) is important for the growth and development of rice and is significant in reducing the costs of rice production. OsNRT1.1b is involved in nitrate assimilation, and the alleles at position 21,759,092 on chromosome 10 clearly separate indica (Pathum Thani 1 (PTT1) and Homcholasit (HCS)) and japonica (Azucena and Leum Pua (LP)) rice varieties. Rice morphological and physiological traits were collected at three nitrogen levels (N0 = 0 kg ha-1, N7 = 43.75 kg ha-1, and N14 = 87.5 kg ha-1). Leaf and tiller numbers in PTT1 and HCS at N7 and N14 were two to three times higher than those at N0. At harvest, the biomass yield in PTT1 was the highest, while the total grain number in HCS was the maximum. The leaf widths and total chlorophyll contents (SPAD units) of Azucena and LP increased with nitrogen application as well as photosynthetic pigment parameters; for example, plant senescence reflectance indices (PSRIs), structure-insensitive pigment indices (SIPIs), and modified chlorophyll absorption ratio indices (MCARIs) were highly related in the japonica varieties. PTT1 and HCS, both carrying the A allele at OsNRT1.1b, had better NUE than Azucena and LP with the G allele. HCS, overall, had better NUE than PTT1. The translation to grain yield of assimilates was remarkable in PTT1 and HCS compared with Azucena and LP. In addition, HCS converted biomass for a 75% higher yield than PTT1. The ability of HCS to produce high yields was achieved even at N7 nitrogen fertilization, manifesting efficient use of nitrogen.

Quantitative Assessment of New Frontiers in Dermatochalasis and Periorbital Hyperpigmentation Treatment: The Role of Cross-Linked Porcine Collagen.

Collagen dermal fillers have shown efficacy in addressing age-related changes in facial appearance. However, their potential in rejuvenating the periorbital region remains unexplored. The aim of this study was to evaluate the effectiveness, clinical safety, and patient satisfaction associated with the utilization of collagen dermal fillers in individuals with dermatochalasis and periorbital hyperpigmentation. This study was reviewed and approved by the institutional review board of China Medical University Hospital (IRB No. CMUH107-REC2-157). Adults diagnosed with dermatochalasis or periorbital hyperpigmentation received periorbital injections of a sterile cross-linked highly-purified specific antigen free porcine dermal collagen (FACIALGAIN® Collagen Implant with Lidocaine, Sunmax Biotechnology Co. Ltd., Taipei, Taiwan) and were assessed for hydration, elasticity, pigmentation index, redness index, lightness value, and density with the DermaLab® Combo Multiparameter Skin Analysis System (Cortex Technology, Hadsund, Denmark) and Cutometer® Dual MPA 580 (Courage+Khazaka electronic GmbH, Köln, Germany). Data was collected prior to injection and at 1 week, 4 weeks, and 12 weeks after injection. Patient satisfaction on volume augmentation, decrease in hyperpigmentation, persistence, and overall satisfaction were also recorded. A total of 12 samples each were recruited for dermatochalasis and periorbital hyperpigmentation. For dermatochalasis subjects, hydration of the periorbital tissue significantly increased at week 1 and 4 (p = 0.011 and p = 0.015). Elasticity decreased by week 4 and persisted until week 12 (p = 0.001 and 0.014). For periorbital hyperpigmentation patients, lightness value increased significantly starting week 1 (p = 0.016), tapering off at week 12. Elasticity decreased by week 4 and persisted until week 12 (p = 0.002 and p = 0.002). Median overall patient satisfaction was 4 out of 5 for the dermatochalasis group and 4.5 out of 5 for the periorbital hyperpigmentation group, with a mild but insignificant decrease by week 12. DermaLab® Combo and Cutometer® Dual MPA 580 are considered effective methods for evaluating patients undergoing dermal filler injections. The utilization of cross-linked porcine collagen dermal filler injections can serve as a minimally invasive approach to enhance skin laxity in dermatochalasis and address discoloration in periorbital hyperpigmentation. However, it is important to note that regular treatments may be necessary to sustain the desired outcomes. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/0026 .

Picosecond Alexandrite Laser With Diffractive Lens Array Combined With Long-Pulse Alexandrite Laser for the Treatment of Facial Photoaging in Chinese Women: A Retrospective Study.

Facial photoaging is a type of facial skin aging induced mainly by exogenous factors (ultraviolet radiation) and often manifests itself in the form of hyperpigmentation, telangiectasia, roughness, increase in fine lines/wrinkles, and enlarged pores. Recently, picosecond lasers have become an emerging option for the treatment of facial photoaging, and long-pulse alexandrite lasers (LPAL) have demonstrated promising potential in the treatment of photoaging-related symptoms. This study aimed to evaluate the efficacy and safety of picosecond alexandrite laser (PSAL) with diffractive lens array (DLA) combined with LPAL for facial photoaging. This is a retrospective study of 20 Chinese female patients with facial photoaging who received PSAL with DLA combined with LPAL during a 1-year period. All patients were treated every 4weeks for a total of three treatments. Objective indicators of facial photoaging and patient satisfaction were evaluated before each treatment, and pain scores and adverse effects were recorded after each treatment. Compared with baseline, patients showed significant differences in all facial photoaging indices (p<0.01). After receiving three treatments, there was a 20.1% decrease in the pigmentation index, a 23.9% decrease in the erythema index, a 34.5% decrease in the texture index, a 28.4% decrease in the fine lines index, a 56% decrease in the pore index, a 9.3% elevation and a 17.1% decrease in elasticity R2 and F4, respectively, and a 55% decrease in sebum content. The mean satisfaction score for the three treatments was 4.67 (3.33, 5.00), and the mean visual analogue scale (VAS) pain score was 7.00. No serious adverse effects such as post-inflammatory hyperpigmentation (PIH), hypopigmentation, or blistering were observed at the treatment site during the treatment period. PSAL with DLA combined with LPAL for the treatment of facial photoaging with significant efficacy, high patient satisfaction, and minimal adverse effects.

Gingival pigmentation in relation to anti-inflammatory salivary interleukin 10, a comparative study.

To assess gingival pigmentation prevalence among students, and its relationship with anti-inflammatory salivary interleukin-10. The observational, cross-sectional, comparative study was conducted at the College of Physical Education and Sport Sciences, Diyala University, Iraq, from December 2021 to March 2022, and comprised students of either gender aged 19-22 years. Students with pigmented gingiva were in group A, while those having no gingival pigmentation were in group B. The level of interleukin-10 was tested using enzyme-linked immunosorbent assay in both groups, and values were compared using the gingival pigmentation index. Data was analysed using SPSS 22. Of the 1,295 students assessed, 1,044(80.62%) were males and 251(19.38%) were females. Pigmented gingiva was found in 118(9.11%), and these students represented group A, while as many subjects were enrolled in controlled group B. Pigmented gingiva was more common among males 81(68.64%) than females 37(31.36%). Salivary interleukin-10 level was significantly increased in group A compared to group B (p<0.05). However, there were no significant differences in mean value of salivary interlukin-10 with respect to severity in group A (p>0.05). Pigmentation was beneficial in terms of gingival protection.

Gingival Depigmentation by 810 nm Diode Laser and Cryosurgery Using 1,1,1,2-Tetrafluoroethane: A Clinical Study

Introduction: Pigmented gingival tissue is a common complaint of patients as unaesthetic. There is a dearth of literature comparing the efficacy of depigmentation by cryosurgery using a biocompatible material 1,1,1,2-tetrafluoroethylene gas and diode laser, which are relatively newer techniques. The study aims to evaluate and compare the efficacy of two different modalities of gingival depigmentation – 810 nm diode laser and cryosurgery using 1,1,1,2-tetrafluoroethane in managing gingival melanin pigmentation. Materials and Methods: A randomised controlled split-mouth trial was conducted on 15 participants. Depigmentation was done using an 810 nm diode laser and a cryosurgery technique using 1,1,1,2-tetrafluoroethane. Re-evaluation was performed at the 1st, 3rd and 6th months postoperatively. Dummett’s Oral Pigmentation Index (DOPI), Hedin’s Melanin Index (HMI), the Visual Analogue Scale for pain and Photometric analysis (RGB scale) were recorded and analysed. Results: DOPI and HMI in the subjects treated by laser and cryosurgery showed statistically significant differences (P &lt; 0.001) from baseline to 1 month, 3 months and 6 months. Intergroup comparison of RGB scores between the laser and cryosurgery depicted no significant difference at baseline (P = 0.06). Conclusions: Cryosurgery using 1,1,1,2-tetrafluoroethylene and laser ablation using an 810 nm diode laser technique was found to be equally effective for treating gingival pigmentation.

A New Index for Assessment of Severity and Extent of Gingival Pigmentation; A Diagnostic Cross-Sectional Study According to Inter and Intra-Observer Variability.

Classification of gingival pigmentation (GP) is often performed using gingival pigmentation index (GPI), melanin pigmentation index (MPI), oral pigmentation index (DOPI), melanin index (MI), or physiologic/pathologic GPI. However, the internal and external reproducibility of these indexes have not been evaluated. This study aimed to introduce a new simple and applicable GPI and assess its internal and external reproducibility. This diagnostic cross-sectional study was conducted on 40 patients with maxillary and mandibular GP. Patients were in the age range of 12-60 years, and degree of GP was determined by four periodontists using DOPI, MI, MPI, GPI and the new index namely the severity and extension of gingival melanotic pigmentation index (SEMPI) under similar environmental and lighting conditions. The inclusion criteria were in the age range of 12-60 years and presence of melanin pigmentation (physiologic or pathologic) in the gingival margin, papilla, or attached gingiva. The exclusion criteria were systemic diseases, vascular lesions, hemochromatosis, amalgam tattoo, hyperbilirubinemia, or use of medications causing nonmelanotic pigmentation (hemoglobin, iron, and amalgam). The Fleiss kappa between all examiners for all indexes at 0, 7, and 14 days was higher than 0.8, indicating high agreement among the examiners. The Spearman's correlation coefficient for all indexes was positive and high at 0, 7, and 14 days (P < 0.001). Considering the high agreement among the examiners for all indexes and at all-time points as well as the positive, strong correlations among them, it seems that the new index is useful for classification of GP.

A Clinical Comparison of ErCr:YSGG Laser and Scalpel Techniques in Gingival Depigmentation.

Gingival depigmentation impacts patient self-confidence and quality of life. This study compares the Er,Cr:YSGG laser to the traditional scalpel technique for reducing gingival hyperpigmentation, assessing their effectiveness and other relevant factors. We conducted a double-blind, randomized trial with a split-mouth design. Forty participants were selected from the university's dental clinic and randomly assigned to receive either the Er,Cr:YSGG laser (2780 nm) or surgical scalpel. Pain intensity and smile satisfaction were assessed post-surgery, and treatment duration was evaluated. The Dummett Oral Pigmentation Index (DOPI) was used to determine the initial severity of pigmentation and to track both reduction and potential repigmentation over time. The Gingival Melanosis Record (GMR) was used to evaluate the presence and extent of pigmentation and to monitor recurrence after 1 and 12 months. Both the Er,Cr:YSGG laser and surgical scalpel similarly reduced GMR and DOPI scores over time, without significant differences at 12 months (p > 0.05). A significant examiner variability was noted in GMR scoring (β &#61; -1.2 for Examiner 2; p < 0.001). Power analysis indicated a higher confidence for detecting treatment effects in DOPI (75%) compared to GMR (55%). Patient satisfaction with smile significantly improved (p < 0.001). Treatment type did not influence postoperative pain levels. The Er,Cr:YSGG laser required longer surgery times (p < 0.001). Under the conditions of the present study, both Er,Cr:YSGG laser and surgical scalpel were equally effective in reducing gingival hyperpigmentation. Although lasers offer better bleeding control and require less anesthesia than the scalpel technique, clinicians should also consider surgery duration, cost, and expertise when selecting a treatment method. Future research should focus on long-term outcomes and economic evaluations, utilizing standardized clinical measures.

Investigating the Impact of Wound Edge Approximation With Skin Grafting on Hypertrophic Scar Reduction: A Randomized Controlled Clinical Trial.

In modern burn care, the focus extends beyond mere patient survival to encompass long-term functional and cosmetic outcomes. Research suggests that the technique and manner of suturing during skin grafting play a significant role in scar formation. This study aimed to explore the effectiveness of wound edge approximation with skin grafting compared to the conventional approach, where the graft edge exclusively interacts with the wound edge, in reducing hypertrophic scar development. Seventy-four burn unit patients eligible for grafting were randomly allocated into 2 groups: those receiving grafts with overlapping edges (Group A) and those receiving grafts with edges tailored to the burn wound (Group B). Evaluation of graft sites occurred immediately post-surgery and at 1 and 6 months post-operatively using the standardized Vancouver Scar Scale (VSS) administered by trained surgeons. The findings of this study revealed that there was no statistically significant difference between the 2 examined groups regarding the average duration of hospitalization and the mean thickness of wounds (P > 0.05). Similarly, the mean scores for pain, vascular index, and pigmentation index immediately post-surgery, at 1 month, and 6 months later, as well as the scar height index and flexibility immediately and at 1-month post-surgery, and the VSS index at the study's conclusion, showed no significant variation between the 2 groups (P > 0.05). However, at the 6-month follow-up, the mean scar height score (P = 0.004) in the overlapping group and the mean flexibility score (P = 0.017) in the non-overlapping group were significantly lower compared to the respective alternative group. This indicates a notable improvement in scar height and wound flexibility in the overlapping group over the non-overlapping group after 6 months.

Spectrum-based deep learning framework for dermatological pigment analysis and simulation

Background:Deep learning in dermatology presents promising tools for automated diagnosis but faces challenges, including labor-intensive ground truth preparation and a primary focus on visually identifiable features. Spectrum-based approaches offer professional-level information like pigment distribution maps, but encounter practical limitations such as complex system requirements. Methods:This study introduces a spectrum-based framework for training a deep learning model to generate melanin and hemoglobin distribution maps from skin images. This approach eliminates the need for manually prepared ground truth by synthesizing output maps into skin images for regression analysis. The framework is applied to acquire spectral data, create pigment distribution maps, and simulate pigment variations. Results:Our model generated reflectance spectra and spectral images that accurately reflect pigment absorption properties, outperforming spectral upsampling methods. It produced pigment distribution maps with correlation coefficients of 0.913 for melanin and 0.941 for hemoglobin compared to the VISIA system. Additionally, the model’s simulated images of pigment variations exhibited a proportional correlation with adjustments made to pigment levels. These evaluations are based on pigment absorption properties, the Individual Typology Angle (ITA), and pigment indices. Conclusion:The model produces pigment distribution maps comparable to those from specialized clinical equipment and simulated images with numerically adjusted pigment variations. This approach demonstrates significant promise for developing professional-level diagnostic tools for future clinical applications.

SUnSeT: spectral unmixing of hyperspectral images for phenotyping soybean seed traits

Key messageHyperspectral features enable accurate classification of soybean seeds using linear discriminant analysis and GWAS for novel seed trait genes.Evaluating crop seed traits such as size, shape, and color is crucial for assessing seed quality and improving agricultural productivity. The introduction of the SUnSet toolbox, which employs hyperspectral sensor-derived image analysis, addresses this necessity. In a validation test involving 420 seed accessions from the Korean Soybean Core Collections, the pixel purity index algorithm identified seed- specific hyperspectral endmembers to facilitate segmentation. Various metrics extracted from ventral and lateral side images facilitated the categorization of seeds into three size groups and four shape groups. Additionally, quantitative RGB triplets representing seven seed coat colors, averaged reflectance spectra, and pigment indices were acquired. Machine learning models, trained on a dataset comprising 420 accession seeds and 199 predictors encompassing seed size, shape, and reflectance spectra, achieved accuracy rates of 95.8% for linear discriminant analysis model. Furthermore, a genome-wide association study utilizing hyperspectral features uncovered associations between seed traits and genes governing seed pigmentation and shapes. This comprehensive approach underscores the effectiveness of SUnSet in advancing precision agriculture through meticulous seed trait analysis.

Ceramic soft tissue trimming bur gingival depigmentation: clinical performance and patient experience. A split mouth randomized controlled trial

BackgroundThe ceramic soft tissue trimming bur (CeraTip™) was initially introduced for use in gingivoplasty but has recently been used for gingival depigmentation. The aim of this study is to compare the efficacy of depigmentation between the novel CeraTip™ and the gold-standard surgical scalpel technique.MethodsEight healthy, nonsmokers with moderate to severe gingival hyperpigmentation in both arches were randomly assigned for CeraTip™ depigmentation in one arch as the test group (TG) and scalpel depigmentation in the opposite arch as the control group (CG). Pigmentation indices were used to assess clinical performance. Treatment time, pain level, and esthetic satisfaction were the parameters of patient experience. The assessments were performed at baseline, one week, one month, and three months.ResultsAt all assessment visits, pigmentation intensity represented by the Dummet oral pigmentation index (DOPI), and pigmentation distribution represented by the Hedin melanin index (MI), were significantly lower than those at baseline (p < 0.001) in both groups. When comparing the two groups, Scalpel depigmentation had better initial clinical outcomes, while CeraTip™ had less visible repigmentation, pain scores, treatment time, and greater esthetic satisfaction. However, none of the differences were statistically significant.ConclusionBoth techniques successfully removed gingival hyperpigmentation with comparable clinical performance. The patients preferred CeraTip™ depigmentation.Trial registrationThe study protocol was registered on 11/09/2023 on the www.clinicaltrials.gov database (NCT06031116) after the approval of the Ethics Committee, Faculty of Dentistry, Ain Shams University (FDASU-Rec012124).

Comparative evaluation of oxygenating agent “blue m gel” and traditional periodontal dressing “Coe-Pak” on patient preference parameters (Pain and wound healing) after surgical depigmentation – A split mouth study

Individuals with high lip line and gummy smile when accompanied withdark colored gingiva have an esthetic concern while smiling. For the management of gingival hyperpigmentation surgical technique with scalpel is still considered the gold standard, although healing may occur by secondary intension and oxygen is one of the essential nutrients for cellular metabolism and production of energy through ATP. It is also involved in collagen synthesis, oxygenative killing of bacteria and angiogenesis. To clinically evaluate and compare the effectiveness of oxygenating agent (Blue M Gel) and traditional periodontal dressing COE-PAK on patient preference parameters (pain and wound healing) after surgical depigmentation. This split-mouth randomized clinical trial was conducted on 5 non-smoking individuals aged 20–40 years irrespective of gender with maxillary or mandibular physiologic gingival pigmentation class (III) and (IV) according to the Dummett–Gupta Oral Pigmentation Index (10 treated sites) who had requested an esthetic treatment for gingival hyperpigmentation of the maxillary or mandibular gingiva. The maxilla or the mandible was randomly divided into two symmetrical parts i.e. from the right second premolar to the midline and from the midline to the left second premolar—to receive either Blue M gel or Coe-Pak as a periodontal dressing after surgical depigmentation with a scalpel. Patient preference parameters such as pain was assessed after 24 hours and 7 days of intervention and re-epithelisation index with toluidine blue was assessed after 1 week and 1 month of intervention. The result of the study demonstrated that pain score and re-epithelisation score was less in Test group (Blue M Gel) as compared to control group (COE-PAK) and was found to be statistically significant. :It can be concluded that Blue M gel can also be a better alternative as a periodontal dressing compared to COE-PAK due to its properties of better healing and decreasing post-operative pain.

Comparative Assessment of Gingival Depigmentation Using Scalpel Versus Microneedling With Ascorbic Acid: A Randomized Controlled Trial.

Background Gingival pigmentation (GP), characterized by the presence of melanin in the gingival tissues, is a common aesthetic concern in dental practice. While it poses no inherent health risks, the visible discoloration may cause psychological distress for individuals seeking optimal dental aesthetics. Understanding the efficacy of various methods is essential for refining treatment strategies and enhancing patient satisfaction in the realm of gingival depigmentation (GD). Aim The objective of the study was to compare the effectiveness of scalpel and microneedling (MN) with ascorbic acid in the treatment of GD. Materials and methods Sixteen patients who had a complaint of GP were included in the study, of whom eight were allocated for depigmentation with a scalpel, and the other eight patients were treated with the MN technique with ascorbic acid. Postoperative wound healing scores were evaluated on the first and seventh days, respectively. The intensity of depigmentation was assessed at baseline, in the first month, and at the end of the third month, respectively. Results The mean Dummett-Gupta Oral Pigmentation Index (DOPI) score at baseline was 2.65±0.16 and 2.61±0.17 in the surgical and microneedling groups with ascorbic acid, respectively. The mean DOPI score at the end of the third month was 1.67±0.39 and 0.87±0.17 in the scalpel and MN with ascorbic acid groups, respectively. There was a statistically significant difference between the scalpel and MN with ascorbic acid groups at the end of the first and third months, respectively, where MN with ascorbic acid showed aesthetically pleasing outcomes. Patients treated with the scalpel technique showed incomplete healing and ulceration on the first and seventh days after the procedure when compared to the MN technique with ascorbic acid. The healing index scores were statistically significant in the MN with ascorbic acid group. Conclusion The MN technique with ascorbic acid is a successful technique for treating GD. It showed aesthetically gratifying outcomes when compared to the conventional surgical technique.

Relationship of skin complexion with gingival tissue color and hyperpigmentation. A multi-ethnic comparative study

Background and ObjectiveThe most frequently seen intra-oral soft tissue is the gingiva. Most often, it is seen as coral-pink tissue that surrounds the neck of the teeth. Gingiva that encircles the tooth necks and covers the alveolar processes of the jaws is an intra-oral tissue that exhibits biomimetic features. The wide range of colors of the gingiva depends on the configuration of gingival vascularity, the degree of epithelial cornification, level of melanogenesis, and the depth of epithelialization. However, the color of the gingiva varies depending on the degree of melanin pigmentation. The current study aimed to identify the different distribution patterns of gingival color and determine the correlation between skin color, gender, and geographical area of origin.Materials and methodsA total of 839 subjects were involved in the study where the gingival color and skin tone were measured using the Dummett-Gupta Oral pigmentation Index (DOPI) combined with VITA VMK MASTER and skin shade method developed by Revlon (USA) and L’Oreal (France) for makeup foundation shades. One investigator was calibrated for the examination of the colors after being tested for normal color vision and color aptitude using the line test.ResultsA significant association was found between skin color and gingival pigmentation (χ2 value (6) = 114.48; P = 0.001). It was also found that females (67.1%) significantly had darker gingiva than males (58.3%). The study statistics display that location of the individual was also statistically associated with melanin pigmentation of the gingiva (χ2 value (57) = 559.33; P = 0.001).ConclusionThe study concluded that gender, skin color, and individual location are significantly associated with gingival melanin pigmentation.

Mapping upland crop–rice cropping systems for targeted sustainable intensification in South China

Upland crop-rice cropping systems (UCR) facilitate sustainable agricultural intensification. Accurate UCR cultivation mapping is needed to ensure food security, sustainable water management, and rural revitalization. However, datasets describing cropping systems are limited in spatial coverage and crop types. Mapping UCR is more challenging than crop identification and most existing approaches rely heavily on accurate phenology calendars and representative training samples, which limits its applications over large regions. We describe a novel algorithm (RRSS) for automatic mapping of upland crop–rice cropping systems using Sentinel-1 Synthetic Aperture Radar (SAR) and Sentinel-2 Multispectral Instrument (MSI) data. One indicator, the VV backscatter range, was proposed to discriminate UCR and another two indicators were designed by coupling greenness and pigment indices to further discriminate tobacco or oilseed UCR. The RRSS algorithm was applied to South China characterized by complex smallholder rice cropping systems and diverse topographic conditions. This study developed 10-m UCR maps of a major rice bowl in South China, the Xiang-Gan-Min (XGM) region. The performance of the RRSS algorithm was validated based on 5197 ground-truth reference sites, with an overall accuracy of 91.92%. There were 7348 km2 areas of UCR, roughly one-half of them located in plains. The UCR was represented mainly by oilseed-UCR and tobacco-UCR, which contributed respectively 69% and 15% of UCR area. UCR patterns accounted for only one-tenth of rice production, which can be tripled by intensification from single rice cropping. Application to complex and fragmented subtropical regions suggested the spatiotemporal robustness of the RRSS algorithm, which could be further applied to generate 10-m UCR datasets for application at national or global scales.

Complement time-series UAV spectral data based on Ambrals kernel-driven model to monitor soil moisture content

ABSTRACT Continuous time-series spectral data are important for inversion of crop or soil information. UAV remote sensing is usually selected under clear and windless weather conditions, but it is not possible to have such weather every day, which results in the UAV not collecting continuous daily spectral information. To explore this issue, we focused on summer maize with four irrigation levels as the research subject. A UAV platform with a multispectral sensor was used to acquire measured spectra of the maize canopy. The solar zenith angle was calculated and substituted into the Ambrals kernel-driven model to obtain simulated spectral data for the maize canopy, and the time-series UAV spectral data were complemented. Then, four vegetation indices (VIs) were established using simulated and measured spectral data, respectively, and the accuracy of the simulated VIs was evaluated. Finally, the simulated and measured VIs were used to monitor and evaluate variations in soil surface moisture content, respectively, and provide irrigation warning. The results demonstrated that Ambrals kernel-driven model can be used to simulate the reflectance of maize canopy collected by UAV. The simulated reflectance can complement time-series UAV spectral data and be used to establish VIs, among which Structure Intensive Pigment Index (SIPI) was established with the highest accuracy (R = 0.729). The VIs established by simulated reflectance can be used to monitor soil surface moisture content, and the monitoring effect is similar to the measured data (R2 = 0.642, RMSE = 0.42). It can evaluate the soil moisture a few days after irrigation and ensure the continuity and timeliness of soil moisture data, so as to improve the crop irrigation system and carry out irrigation warning. These results have certain reference for the supplementation of time-series spectral data and farmland irrigation using UAV multispectral remote sensing.

Comparison between clinical and computerized methods for assessing gingival pigmentation.

Digital computerized assessment can provide objective values for the measurement of gingival pigmentation. This study aims to compare the Commission Internationale de l'Eclairage Lab color space (CIELAB) values and the computerized intensity values (CIVs) from digital imaging with clinical evaluations using the Dummett-Gupta Oral Pigmentation Index (DOPI) for assessing gingival pigmentation in a multi-ethnic population. Digital photographs of 188 participants were taken using standardized parameters. The buccal gingival pigmentation was evaluated using three methods (a) a clinical evaluation by two independent assessors using the DOPI, (b) the CIELAB values using the Adobe Photoshop® software (Version 23.1.1) and (c) the CIV calculated using the ImageJ software (Version 1.53k). A hierarchical clustering analysis was used to identify colour groups that clustered together. Agreement between the clinical and digital categorization of the pigmentation was carried out using weighted kappa analysis. Agreements between CIELAB and CIV were compared using intra-class correlation coefficient. There was a statistically significant difference in the DOPI, the L*, a*, and b* coordinates, and the CIV between the different ethnic groups of the participants. Cluster analysis for the CIELAB and CIV both identified four clusters. The gingival pigmentation categorization using the L*, a*, and b* values moderately agreed with the clinical evaluation using the DOPI index while the categorization with the CIV was in slight agreement with the clinical evaluations. This study identified four clusters of gingival pigmentation in 188 multi-ethnic participants. The clusters, determined by CIELAB values, align with the clinical assessment of gingival pigmentation. Digital measurements derived from clinical photographs can serve as an effective means of pigmentation measurement in dental clinics.