A comparative study of the application of three digital imaging techniques to assess the thickness of the palatal mucosa of the maxillary anterior teeth.

BACKGROUND: This study highlights the need for precise and efficient methods to measure palatal mucosal thickness in the maxillary anterior teeth, particularly for soft tissue augmentation in the aesthetic zone. The research evaluates three digital imaging techniques, suggesting that Cone Beam Computed Tomography (CBCT) combined with intraoral scanners (IOS) is a promising approach for reliable clinical assessment. METHODS: Ten volunteers with healthy periodontium were selected, and three methods were employed: CBCT-based indirect gingival imaging, modified soft tissue CBCT (ST-CBCT), and CBCT combined with IOS. Measurements of palatal mucosal thickness were taken at multiple points along the palatal gingival margin. Statistical analysis included Bland-Altman plots for method agreement and intraclass Correlation Coefficient (ICC) analysis for reliability. All measurements were standardized, repeated for consistency, and accurate to 0.01 mm to ensure reliability. RESULTS: The Bland-Altman plots showed that less than 5% of the points for palatal mucosal thickness differences measured by the gingival indirect radiographic method, modified ST-CBCT, and CBCT combined with IOS were located outside the 95% limits of agreement (LoA). The mean value of the differences was within 0.2 mm, indicating good clinical agreement among the three methods. The inter- and intra-study ICC values for palatal mucosal thickness measurements of the maxillary anterior teeth using the three CBCT methods were greater than 0.75 (P < 0.001), demonstrating reproducibility. CONCLUSIONS: Based on the evaluation of three digital imaging techniques, this study indicates that the combination of CBCT with IOS is a feasible method for measuring palatal mucosal thickness in the maxillary anterior teeth and demonstrates good reproducibility.

[Influence of gingival biotype width on the health of peri-implant bone and soft tissues and the aesthetic outcome of the gingival papilla for single maxillary posterior implants].

PURPOSE: To explore the influence of gingival biotype and width of keratinized gingiva on peri-implant bone tissue, soft tissue health, and esthetic outcome of the papilla surrounding single posterior maxillary implants. METHODS: Seventy-eight patients who underwent single posterior maxillary implant surgery from May 2019 to September 2022 were selected, involving the placement of 78 implants. Based on periodontal probing outcomes one month post-restoration, the patients were divided into thin gingival biotype group(n=32) and thick gingival biotype group(n=46). Comparisons were made six months after implant restoration regarding buccal keratinized mucosa width(KMW), peri-implant bone tissue [implant bone loss(IBL)], soft tissue health [modified plaque index (mPLI), modified bleeding index for implants (mBLI), probing pocket depth (PPD)], and esthetic effect of the papilla [papilla index score (PIS), food impaction, gingival margin color satisfaction index (GMCS)]. Statistical analysis was performed with SPSS 27.0 software package. RESULTS: The thick gingival biotype group showed significantly greater keratinized gingival width compared to the thin gingival biotype group (P＜0.05). Spearman correlation analysis revealed a positive correlation between gingival biotype and keratinized gingival width(r=-0.416, P=0.000). For peri-implant bone tissue, bone loss in the thin gingival biotype group was significantly higher than that in the thick gingival biotype group. In soft tissue health, the probing pocket depth for implants in the thin gingival biotype group was significantly less than that in the thick gingival biotype group. In terms of esthetic effect of the papilla, PES score in the thin gingival biotype group was significantly lower than in the thick gingival biotype group(P＜0.05). Pearson correlation analysis showed a negative correlation between gingival biotype and papilla index score, GMCS, bleeding on probing, and PPD, but a positive correlation with food impaction, bone loss and mPLI(P＜0.05). The width of keratinized gingiva was positively correlated with papilla index score, GMCS, bleeding on probing and PPD, but negatively correlated with food impaction, bone loss and mPLI(P＜0.05). There was significantly difference between thin and thick gingival biotype groups for KMW >2 mm(P＜0.05). A significant difference was showed in thick gingival biotype group when KMW ≤2 mm and ＞2 mm(P＜0.05). CONCLUSIONS: Gingival biotype and keratinized mucosa width significantly influence peri-implant bone and soft tissue health as well as esthetic outcome of the papilla around single posterior maxillary implants, offering guidance for predicting the long-term success and esthetic outcomes of implants.

Marginal Gingival Thickness Assessment in Three- To Six-Year-Old Preschool Children.

Purpose: Although gingival thickness has been extensively studied in permanent dentition, the literature regarding marginal gingival thickness in primary dentition is insufficient. The purpose of this study was to assess the variations in marginal gingival thickness in preschool-age children. Methods: A cross-sectional study of 4,109 primary teeth was conducted. Using a reamer, the transgingival probing method was employed to assess marginal gingival thickness in healthy preschoolers. Inter-examiner and intra-examiner reproducibility were assessed via the intraclass correlation coefficient. Results: Descriptive statistics revealed that primary maxillary left second molars had the highest mean marginal gingival thickness (1.06 mm), whereas primary mandibular right central incisors had the lowest mean marginal gingival thickness (0.74 mm). Gender-based independent sample t-tests revealed significant differences in the values of primary maxillary right canines (females had greater values than males; P=0.03) and primary mandibular right first molars (males had greater values than females; P=0.01). An inter-arch comparison revealed significant differences between the primary second molars (maxillary more than mandibular; P=0.001). Conclusions: This study reports the first documented marginal gingival thicknesses of primary dentition. It reveals substantial variations in the values of primary maxillary right canines and primary mandibular right first molars and between primary maxillary and mandibular second molars.

Influence of gingival color on the color differences of dental laminate veneers.

STATEMENT OF PROBLEM: The effect of various gingival colors on the color differences of laminate veneers is unclear and comparative evaluations should be documented. PURPOSE: The purpose of this in vitro study was to investigate the influence of different gingival colors on the color differences of laminate veneers. MATERIAL AND METHODS: Five maxillary typodonts were used to obtain study models using 5 different gingival colors: light pink (LP), dark pink (DP), orange (Or), brown (Br), and violet (V). A total of 45 laminate veneers were milled using A1-shaded lithium disilicate ceramic and cemented on natural tooth-colored substrates. Color parameters were assessed using a spectroradiometer at 3 measurement areas (cervical third, mid-third, and incisal third) along the midline of laminate veneer with a focus measuring diameter of 1 mm. Color differences (∆E*ab and ∆E00) were calculated and compared with perceptibility (PT: ∆E*ab=1.22, ΔE00=0.81) and acceptability (AT: ∆E*ab=2.66, ΔE00=1.77) visual thresholds. Color variation data were statistically analyzed using 2-way ANOVA and Tukey HSD tests (α=.05). RESULTS: Two-way ANOVA results of the ∆E*ab values revealed significant interaction between the gingival color and the measurement area (P=.002). The ∆E*ab and ΔE00 values of laminate veneers were significantly higher in the LP-V group that presented values above AT (P<.001). Measurement area significantly influenced ∆E values of laminate veneers (P<.001). Greater ∆E values were registered at the measurement area of the cervical third in the groups of LP-DP, LP-Br, LP-V, and Or-V. Regardless of the measurement area, ∆E00 values below AT were obtained for the gingival color groups of LP-Or, DP-Or, DP-Br, and DP-V. CONCLUSIONS: Gingival color influenced the color differences of laminate veneers. When the gingival color was a darker gingival color, rather than light pink, the color difference increased, especially at the measurement area of the cervical third.

Integrated correlation analysis of the thickness of buccal bone and gingiva of maxillary incisors.

OBJECTIVE: This study aimed to validate the integrated correlation between the buccal bone and gingival thickness of the anterior maxilla, and to gain insight into the reference plane selection when measuring these two tissues before treatment with implants. METHODOLOGY: Cone beam computed tomography (CBCT) and model scans of 350 human subjects were registered in the coDiagnostiX software to obtain sagittal maxillary incisor sections. The buccal bone thickness was measured at the coronal (2, 4, and 6 mm apical to the cementoenamel junction [CEJ]) and apical (0, 2, and 4 mm coronal to the apex plane) regions. The buccal gingival thickness was measured at the supra-CEJ (0, 1mm coronal to the CEJ) and sub-CEJ regions (1, 2, 4, and 6 mm apical to the CEJ). Canonical correlation analysis was performed for intergroup correlation analysis and investigation of key parameters. RESULTS: The mean thicknesses of the buccal bone and gingiva at different levels were 0.64~1.88 mm and 0.66~1.37 mm, respectively. There was a strong intergroup canonical correlation between the thickness of the buccal bone and that of the gingiva (r=0.837). The thickness of the buccal bone and gingiva at 2 mm apical to the CEJ are the most important indices with the highest canonical correlation coefficient and loadings. The most and least prevalent subgroups were the thin bone and thick gingiva group (accounting for 47.6%) and the thick bone and thick gingiva group (accounting for 8.6%). CONCLUSION: Within the limitations of this retrospective study, the thickness of the buccal bone is significantly correlated with that of the buccal gingiva, and the 2 mm region apical to the CEJ is a vital plane for quantifying the thickness of these two tissues.

Comparison of smile attractiveness in cases with gummy smile treated with botulinum toxin and maxillary impaction surgery: A retrospective study.

This study aimed to compare the smile's attractiveness in patients submitted to the treatment of gummy smiles with botulinum toxin or maxillary impaction surgery. The retrospective sample comprised 26 patients divided into two groups: Group 1 (BTX): 13 patients (12 females and 1 male) with a mean age of 28.06 years (s.d. = 6.09) and mean gingival exposure during smile of 5.18 mm (s.d. = 1.51) treated with botulinum toxin; Group 2 (SURGICAL): 13 patients (9 females and 4 males) with a mean age of 30.59 years (s.d. = 5.72) and mean gingival exposure during smile of 5.21 mm (s.d. = 1.55) treated with orthognathic maxillary impaction surgery. The group of evaluators comprised 317 participants, divided into 143 orthodontists (85 females and 58 males) with a mean age of 41.40 (s.d. = 9.30); 62 dentists (47 female and 15 male) with a mean age of 35.44 (s.d. = 10.44), and 112 lay people (74 female and 38 male) with a mean age of 46, 91 (s.d. = 10.11) in a questionnaire on Google Forms. Without knowing the therapy used, the evaluators assigned scores to the photographs of the posed smile taken before (T1) and after (T2) treatment. Intergroup comparison of smile attractiveness was performed using the t-independent, one-way ANOVA, and Tukey tests. There was a significant improvement in smile attractiveness with treatment in both groups; however, the improvement was significantly better in the surgical group than in the BTX group. Orthodontists rated smile attractiveness significantly higher than dentists and laypersons for the final phase of the BTX and surgical groups. There was a significant improvement in the smile attractiveness with botulinum toxin application and orthodontic-surgical treatment. However, orthognathic surgery promoted a greater improvement in smile attractiveness than the application of botulinum toxin.

Comparison of gingival thickness by CBCT versus transgingival probing and estimation of cut-off values for gingival phenotype - A cross-sectional study in adults.

AIM: Gingival phenotype (GP) is regarded as a valuable indicator for forecasting the probability of attaining favourable aesthetic and functional results with orthodontic treatment. This study aimed to investigate the accuracy and reproducibility of cone beam computed tomography (CBCT) for assessing gingival thickness (GT) in both arches compared to the transgingival probing method. The secondary objective was to determine the optimal cut-off values for GT using CBCT. METHODS: This cross-sectional study was conducted where GP was determined based on the probe transparency method (TRAN). The GT measurements were obtained by both methods at 2mm from the free gingival margin (FGM) for all teeth anterior to the first molar. The data was statistically analysed using intraclass correlation coefficient (ICC), Bland-Altman plots, and receiver operating characteristic (ROC) curves. The statistical significance level was set at a P-value<0.05. RESULTS: The study included 60 subjects (1200 teeth). The mean GT in both the maxillary (1.14±0.17mm) and mandibular (0.94±0.15mm) arches was significantly greater (P<0.05) for the transgingival probing method than for the CBCT method. As shown in the Bland-Altman plot, the bias between the two methods was greater in the maxillary jaw (0.060; 95% CI: 0.044 to 0.076) and in individuals with a thick GP (0.096; 95% CI: 0.082 to 0.109). The optimal values for GT measurements were 1.15mm for the maxillary jaw, 1.02mm for the mandibular jaw, 1.02mm for males, and 1.09mm for females. CONCLUSIONS: CBCT exhibited notable precision in diagnosing GT, while demonstrating minimal disparities compared to the conventional transgingival probing technique, particularly evident in thin GPs, and in the mandibular dental arch. The constraints associated with the utilization of CBCT were observed in the maxillary arch and in cases with thick GP.

Assessment of gingival translucency at the mandibular incisors with two different probing systems. A cross sectional study.

OBJECTIVES: Increasing evidence indicates that the thickness of periodontal soft tissues plays an important role in various clinical scenarios, thus pointing to the need of further clinical research in this area. Aim of the present study was to assess gingival thickness at the mandibular incisors by translucency judgement with two different probes and to validate if these methods are comparable and applicable as diagnostic tools. MATERIALS AND METHODS: A total of 200 participants were included; gingival tissue thickness was measured by judging probe translucency at both central mandibular incisors, mid-facially on the buccal aspect of each tooth using a standard periodontal probe and a set of color-coded probe, each with a different color at the tip, i.e. Colorvue Biotype Probe (CBP). Frequencies and relative frequencies were calculated for probe visibility. Agreement between the standard periodontal probe and the CBP was evaluated via the kappa statistic. RESULTS: When the periodontal probe was visible, the frequency of CBP being visible was very high. Kappa statistic for the agreement between the standard periodontal probe and the CBP was 0.198 (71.5% agreement; p-value < 0.001) for tooth 41 and 0.311 (74.0% agreement; p-value < 0.001) for tooth 31, indicating a positive association of the two methods. CONCLUSIONS: An agreement that reached 74% was estimated between the standard periodontal probe and the color-coded probe at central mandibular incisors.  CLINICAL RELEVANCE: In the context of the present study, the two methods of evaluating gingival thickness seem to produce comparable measurements with a substantial agreement. However, in the 1/4 of the cases, the visibility of the color-coded probe could not assist in the categorization of the gingival phenotype.

[Dynamic monitoring and esthetic evaluation of dimensional changes in the peri-implant soft tissue contour after the immediate implant placement and provisionalization with the modified socket-shield technique in the esthetic zone].

Objective: To accurately measure the dynamic changes of peri-implant soft tissue within one year after the immediate implant placement and provisionalization with the modified socket-shield technique (MSST) in the esthetic zone, and to provide a basis for evaluating the effect of the modified socket-shield technique on the maintenance of peri-implant soft tissue. Methods: A total of 22 patients (22 implants) were prospectively included 1 year after completion of immediate implant placement and provisionalization (IIPP) within MSST in the esthetic zone from January 2022 to January 2024 at the Department of Oral Implantology in the Stomatological Hospital of Chongqing Medical University. The intraoral optical models of patients were obtained by an intraoral scanner system preoperatively and at 3, 6, and 12 months postoperatively, respectively. The standard tessellation language files of intraoral optical models at multiple time points were imported to Geomagic Studio 2013 to be superimposed and aligned for analyzing the peri-implant soft tissue contour on the labial side of the implant site at multiple levels. The amount of gingival margin recession, gingival papilla change, and thickness change of the labial side of the soft tissues at each postoperative point in time were measured at each postoperative time point, as well as evaluating the esthetic effect by the pink esthetic score (PES). Results: The patients were (40±13) years old (21-75 years), including 9 males and 13 females. No adverse events occurred in all the implants during the 12-month follow-up period. The recession level of the gingival margin of the implant site (GL) was 0.08 (0.07) mm, the recession level of the mesial papilla (ML) was 0.19 (0.25) mm, and the recession level of the distal papilla (DL) was 0.19 (0.10) mm. The average collapse thickness of the soft tissue contour on the labial side of the implant (ΔD) was (0.39±0.09) mm, mainly occurring within 2 mm of the root of the gingival margin. The height of the alveolar bone was reduced by (0.17±0.08) mm. The thickness of the labial alveolar bone at 1, 3, and 5 mm root side of the implant shoulder was reduced by (0.13±0.08), (0.12±0.10) and 0.04 (0.17) mm, respectively. The postoperative pink esthetic score was 13.00 (2.25) points at 12 months, which suggested that all implant sites achieved ideal esthetic results. Conclusions: The labial soft tissue contour at implant sites shows minimal change following immediate implant placement and provisionalization using the modified socket-shield technique for 1 year in the esthetic zone.

Exploring Digital Gingival Shade Matching in Students.

PURPOSE: To study the degree of accuracy in gingival shade matching of undergraduate students using a computer application. MATERIALS AND METHODS: In total, 76 undergraduate dental students' gingival shade selection abilities were evaluated using an in-house developed computer application. A total of 15 intraoral gingival photographs and 21 pink gingival color porcelain samples were used. The environmental conditions were standardized, and no time limit was set for answering in the computer application. RESULTS: Fourteen gingival color samples (66.6%) were not useful for representing the studied gingival shades. Not all natural gingival colors studied were represented within the 50.50% acceptability limits of the pink samples. There were no statistically significant differences between men and women in terms of "hit" percentages. The highest correlation coefficient (in absolute value) was for the L* coordinate (the darker the gingiva in the picture, the higher the hit rate for choosing the "ideal" shade tab); however, none of the linear correlation coefficients were statistically significant. CONCLUSIONS: Not all colors provided in the pink ceramic system were useful for subjective gingival selection. There were no statistically significant differences between male and female dental students in gingival color perception. The L* coordinate was the only one that influenced the correct perception of gingival color by dental students, and it did so more in women than in men.

Trueness and precision of an intraoral scanner on abutments with subgingival vertical margins: An in vitro study.

OBJECTIVES: This study aimed to evaluate the accuracy of an intraoral scanner (IOS - Medit i700) on tooth abutments with vertical preparations at 2 depths below the free gingival margin, and to determine if the IOS can reproduce the area beyond the finish surface of the tested preparation geometry. METHODS: Two abutments for a maxillary first molar were designed by means of CAD software, with vertical preparations set at 1 and 2 mm below the gingiva. These abutments were subsequently printed in resin and placed on a reference model. The reference files consisted of scans made using a metrological machine on these abutments. Ten scans were made with the tested IOS on each sample, resulting in two study groups. The scans from the experimental groups were labeled "V-1″ for vertical preparation at 1 mm below the gingival margin and "V-2″ for 2 mm below. The analysis of these scans was performed using Geomagic Control X (3D SYSTEMS) to assess their trueness and precision in µm. Descriptive statistics with a 95 % confidence interval were employed, alongside independent sample tests, to ascertain any differences between the groups (α=0.05). RESULTS: Statistically significant differences were not found both for trueness (p=.104) and precision (p=.409), between the tested geometries. The mean values for trueness were V-1 = 37.5[31.4-43.6]; V-2 = 32.6[30.6-34.6]. About the precision, the mean values were V-1 = 20.5[8.4-32.5]; V-2 = 18.4[8.2-28.5]. In both the study groups, it was possible to detect the surface beyond the finish area. CONCLUSIONS: Within the limitations of this study, vertical preparation design allows for registration of the tooth anatomy beyond the finish area with IOS. Moreover, the mean accuracy values were clinically acceptable at both 1 and 2 mm below the gingival margin.

Gingival thickness and gingival width in children: a cross-sectional study utilizing ultrasonography.

PURPOSE: To measure the gingival phenotype-related features, gingival thickness (GT) and gingival width (GW), in healthy children and to investigate their association between them, with age, gender, tooth-type and arch. METHODS: The gingival sites of 1029 teeth were included from 64 children (36 males and 28 females), with primary and mixed dentition, attending the paediatric dental clinic of Aristotle University, Thessaloniki. GT and GW were measured ultrasonically and with a periodontal probe, respectively. Mixed effects linear regression models were used to evaluate the association of gingival thickness and gingival width with the under-investigation parameters. Spearman's correlation coefficient was used to evaluate correlation between GT and GW. RESULTS: Significantly thicker gingiva is found in posterior teeth compared to anterior teeth, in permanent teeth versus primary teeth and in maxillary teeth in comparison to mandibular teeth (p value < 0.001). Regarding GW, significantly wider gingiva is noted in posterior regions (p value = 0.022) and the maxilla (p value < 0.001). Gender-wise and concerning age GT and GW are not significantly affected. A weak and positive correlation between GT and GW is noted (rho 0.30, p < 0.001). CONCLUSIONS: GT and GW present significant associations with arch and tooth-type. Findings from this study fulfil the further understanding of GT and GW of paediatric patients that are investigated sparsely throughout the literature and demonstrate an accurate, painless and simple method to map the gingiva.

Explaining the colour of natural healthy gingiva.

To examine the differences between natural gingival colour in men and women. To determine the degree of predictability of changes in the gingival colour coordinates recorded for healthy gingiva, according to age, long-term medication, frequency of toothbrushing, and smoking habits. The CIELAB colour coordinates were recorded using a spectrophotometer for 360 Caucasian adult participants (aged 18-92 years), in three zones of the healthy attached gingiva of the maxillary central incisor. Regression models were created for each zone and each sex, taking the L*, a* and b* coordinates as dependent variables and age, frequency of toothbrushing, smoking habits (0-non-smoker; 1-smoker) and whether participants were taking long-term medication (0-no; 1-yes) as independent variables. The statistical analysis was conducted with SPSS version 26.0, using multiple regression models. Statistically significant differences between men and women were found only for colour coordinate b*, in all three zones. The only colour coordinate on which the predictor variables had a significant effect was the L* coordinate. In men, age and long-term medication had the greatest effect as predictors (maximum R2 = 0.149). In women, frequency of toothbrushing was the strongest predictor in the predictive models (maximum R2 = 0.099). The colour of gingiva in men contained a larger amount of blue, given that significantly lower values for colour coordinate b* were recorded in men than women, although this difference lacked clinical implications. For both sexes, the regression models produced had a modest predictive capacity. The L* coordinate was the dependent variable that showed the greatest predictability.

Relationship between soft tissue dimensions and tomographic radial root position classification system for immediate implant installation.

The aim of this study was to evaluate the relationship between soft tissue dimensions and radial root position (RRP) classification for immediate implant placement on maxillary anterior teeth. Maxillary anterior teeth (n = 420) were analyzed in the radial plane of cone beam computed tomography (CBCT) scans. Each tooth was classified according to its RRP: class I, (IA, IB); class II (IIA, IIB) class III; class IV, and class V. Soft tissue thickness at different landmarks, supracrestal soft tissue height, and crestal bone thickness were measured in CBCT. Keratinized tissue width was clinically measured. Gingival phenotype (thick or thin) was evaluated by transparency of the periodontal probe and at the landmark 2 mm from the gingival margin in CBCT. Class I tooth position accounted for 31.7%, class II for 45%, class III for 13.3%, class IV for 0.5%, and class V for 9.5%. The gingival phenotype was associated with RRP (χ2 test, p < 0.05). Soft tissue dimensions were significantly different over RRP classes (ANOVA and Tukey tests, p < 0.05). Types IA and IIA presented both thick soft and hard tissues. When planning immediate implants in the anterior maxilla, soft tissue dimensions evaluation should be incorporated into RRP classification to increase the accuracy and predictability of treatment outcomes.

Thermographic examination of gingival phenotypes: correlation between morphological and thermal parameters.

OBJECTIVES: To evaluate the clinical and thermographic aspects of the gingival phenotype (GP) in healthy subjects. MATERIALS AND METHODS: The study sample examined 264 teeth, upper and lower incisors, comprising 132 central incisors (CI) and 132 lateral incisors (LI), in 33 healthy volunteers. Four periodontal parameters were recorded systematically: ratio of width to length of the dental crown (CW/CL), height of the gingival attachment (KGW), probing depth (PD), and gingival transparency (GT). The temperatures of the attached gingiva (KGW temp) and the free gingival margin (FGM Temp) were also recorded by way of infrared thermography (IRT). RESULTS: The average age of the sample was 30.70 ± 7.65 years. Of the 264 teeth evaluated, 76.1% had a thin GP. There was a significant association between CW/CL (p < 0.001), KGW (p < 0.001), PD (p < 0.007), and FGM Temp (p < 0.006) with the tooth groups. The results show a significant and inversely proportional correlation between clinical parameters and gingival temperature (p < 0.05). A significant association was found between CW/CL (p < 0.026); KGW (p < 0.001); and GP. CONCLUSION: CW/CL, KGW, PD, and FGM Temp vary according to tooth group. The majority of the sample presented with the thin GP, which was more prevalent in the lower LIs and CIs. No significant association could be observed between thermographic parameters and GP. CLINICAL RELEVANCE: Knowledge of the temperature of the gingival tissues can be useful in helping to diagnose and plan periodontal treatments. Moreover, our findings will help future studies evaluate the use of IR as an auxiliary diagnostic method in dentistry, eliminating GP as a confounding factor, since it does not seem to influence the temperature of the gingival tissues.

Clinical and histologic evaluation of heterotopic mucosa transpositioning at teeth and dental implants.

AIM: To investigate the healing after heterotopic mucosa transpositioning at dental implants and teeth. MATERIALS AND METHODS: One hemimandible per dog (n = 4) was allocated to receive 3 implants (test), whereby 3 premolars on the contralateral side served as controls. After osseointegration, a Z-plasty was performed on the buccal aspect of the test and control sites to heterotopically move the zone of keratinized tissue (KT) into a region with non-keratinized tissue (nKT) and vice versa. Clinical measurements were performed before (T0) and at 12 weeks following heterotopic transposition (T1). Thereafter, specimens were processed for histological analysis. RESULTS: Clinical measurements revealed that at T1, a band of KT was reestablished at teeth (mean: 2.944 ± 1.866 mm), whereas at implants, the transpositioned nKT resulted in a mucosa without any signs of keratinization (mean: 0 mm; p < .0001). At implant sites, the probing attachment level loss was more pronounced compared to tooth sites (-1.667 ± 1.195 mm and -1.028 ± 0.878 mm, respectively; p = .0076). Histologically, the transpositioned nKT, was accompanied by the formation of KT at the tooth but not at implant sites. The supracrestal soft tissues were statistically significantly higher at tooth compared to implant sites (2.978 ± 0.483 mm and 2.497 ± 0.455 mm, p = .0083). The transpositioned KT remained mostly unaltered in its morphological characteristics. CONCLUSIONS: The findings of this study indicate that: (a) transpositioned KT may retain its morphological characteristics; and (b) transpositioned nKM was accompanied by the formation of KT at the tooth but not at implant sites.

Histological Techniques for the Study of the Dentogingival Junction: A Scoping Review Using the Anatomical Quality Assurance Checklist (AQUA) / Técnicas Histológicas para el Estudio de la Unión Dentogingival: Una Revisión de Alcance Utilizando el Anatomical Quality Assurance Checklist (AQUA)

SUMMARY: The dentogingival junction (DGJ) is an adaptation of the oral mucosa composed of epithelial and connective tissues intimately related with the mineralised tissues of the tooth. The histological evidence available is mainly based on studies in animals, separate evaluations of hard and soft tissues, and studies using conventional histological techniques that eliminate the enamel from preparations. The aim of this study was to carry out a review of the existing evidence on histological techniques available for study of the tooth and periodontium in conjunction in humans. A scoping review was carried out of the available literature referring to study of the tooth and the periodontium in conjunction in humans, in the Web of Science (WoS), EMBASE, Scopus and SciELO databases, using the terms "Histological Techniques"[Mesh]) and "Epithelial Attachment"[Mesh]. One hundred and fifty-nine articles were found, of which 54 were selected for full- text reading. Ten were finally included in the qualitative synthesis, and we applied the Anatomical Quality Assurance (AQUA) checklist for analysis the methodological quality of the selected articles. The results showed that the only articles with a low risk of bias in all five domains according to the AQUA criteria corresponded to Silva et al. (2011) and Agustín-Panadero et al. (2020). Finally, we conclude that the quality of the histological sections to observe tissues that simultaneously contain the tooth and the periodontium, is conditioned by the selected technique and by the care required in certain specific tasks during the histological processing of the samples.

La unión dentogingival (DGJ) es una adaptación de la mucosa oral compuesta por tejidos epitelial y conectivo íntimamente relacionados con los tejidos mineralizados del diente. La evidencia histológica disponible se basa principalmente en estudios en animales, evaluaciones separadas de tejidos duros y blandos y estudios utilizando técnicas histológicas convencionales que eliminan el esmalte de las preparaciones. El objetivo de este estudio fue realizar una revisión de la evidencia existente sobre las técnicas histológicas disponibles para el estudio del diente y el periodonto en conjunto en humanos. Se realizó un scoping review de la literatura disponible referente al estudio del diente y el periodonto en conjunto en humanos, en las bases de datos Web of Science (WoS), EMBASE, Scopus y SciELO, utilizando los términos "Histological Techniques"[Mesh]) y "Epithelial Attachment"[Mesh]. Se encontraron 159 artículos, de los cuales 54 fueron seleccionados para lectura de texto completo. Diez fueron finalmente incluidos en la síntesis cualitativa, y se aplicó la lista de verificación Anatómica Quality Assurance (AQUA) para el análisis de la calidad metodológica de los artículos seleccionados. Los resultados mostraron que los únicos artículos con bajo riesgo de sesgo en los cinco dominios según los criterios AQUA correspondían a Silva et al. (2011) y Agustín-Panadero et al. (2020). Finalmente, concluimos que la calidad de los cortes histológicos para observar los tejidos que contienen simultáneamente el diente y el periodonto, está condicionada por la técnica seleccionada y por el cuidado requerido en ciertas tareas específicas durante el procesamiento histológico de las muestras.

The buccal corridor as a possible morphological risk indicator for sleep disordered breathing.

OBJECTIVE: To explore a possible morphological relationship between buccal corridor, gingival display, transpalatal molar width, palatal height, and a cephalometric measurement (PV-A Line) as a risk indicator for sleep-disordered breathing. MATERIALS AND METHODS: Thirty subjects were enrolled. Full face maximum smile images and CBCT scans were taken. A Pearson correlation coefficient was used to identify any relationships between the variables. RESULTS: No correlations were identified between any of the variables investigated in this study as they relate to risk factors for sleep-disordered breathing. CONCLUSIONS: The amount of buccal corridor space in relation to a patient's smile and the amount of gingival display does not appear to be a reliable metric in identifying certain morphological risk factors for sleep-disordered breathing. CLINICAL SIGNIFICANCE: Assessing the amount of buccal corridor space in relation to a smile does not appear to be a reliable predictor of morphological risk for certain risk factors of sleep-disordered breathing. In addition, utilizing the amount of gingival display in a patient's maximum smile does not appear to relate directly to risks in sleep-disordered breathing. Other tests and discovery may be necessary to identify these types of patients.

Morphological changes in alveolar bone thickness and height after orthodontic proclination or labial movement combined with autogenous soft tissue grafting: a CBCT evaluation.

BACKGROUND: Autogenous soft tissue grafting is indicated in thin gingival biotypes before orthodontic proclination or labial movements to increase the keratinized gingiva and prevent gingival recession. However, its effect on local alveolar bone remodeling is unclear. The aim of this study was to investigate the effects of autogenous soft tissue grafting on local alveolar bone after orthodontic proclination or labial movements. METHODS: Sixteen patients with a thin scalloped gingival biotype, narrow keratinized gingiva, or thin cortical bone requiring orthodontic proclination or labial movement of teeth were included. Cone-beam computed tomography (CBCT) images were obtained before grafting and at least 6 months after surgery. Sixty mandibular teeth were included, and the vertical bone level and horizontal labial bone thickness were measured. The results were compared using paired t-tests or Wilcoxon signed-rank test. RESULTS: The horizontal labial bone thickness increased, especially at 6 mm below the cementoenamel junction (CEJ) in the mandibular central and lateral incisors (P < 0.05). The total alveolar bone area of the canines, first premolars, and second premolars increased at 3, 6, and 9 mm below the CEJ, respectively, and the differences were statistically significant (P < 0.05). Additionally, vertical bone height increased minimally on the labial side, but the differences were not statistically significant (P > 0.05). CONCLUSIONS: New bone regeneration was observed on the labial (pressure) side after autogenous soft tissue grafting, which may represent a mechanism to effectively prevent gingival recession and maintain periodontal health. IRB APPROVAL: All the experimental procedures involving humans in this study were approved by the Medical Ethics Committee of Xiangya Stomatological Hospital, Central South University ( No. 20190048).