Reproducibility of the PIROP ultrasonic biometer for gingival thickness measurements

Using the Modified Apical Access Technique to Treat Peri-Implant Mucosa Defects: Description of the Technique and Three-Dimensional Quantitative Measurement of Buccal Augmented Tissue

The importance of augmenting the peri-implant soft- and hard-tissue architecture is now widely accepted. However, while most contemporary research supports this premise, clinicians are encountering peri-implant soft tissue defects with increasing frequency, which they are therefore required to reconstruct. These complications can result from the difficulty of establishing an appropriate diagnosis and treatment plan or from suboptimal clinical situations (implant malposition, insufficient vestibular alveolar bone thickness or inadequate mucosal thickness). In this context, it is the peri-implant soft-tissue phenotype that most influences esthetic and health-related results in the short and long term. This article describes two clinical cases in which a modification of the apical access technique is presented that may be useful in clinical scenarios requiring large gains in mucosal thickness. Use of the modified bilaminar apical access with de-epithelialized free gingival graft technique showed promising results, with a significant increase in mucosal thickness and satisfactory outcomes in esthetics and peri-implant health.

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.

A comparison of alveolar ridge mucosa thickness in completely edentulous patients

PURPOSE

The purpose of this cross-sectional clinical study was to determine and compare alveolar ridge mucosa thickness at crestal, buccal, and lingual locations of the maxillary and mandibular arches in completely edentulous patients using a dedicated, ultrasonic gingival scanner.

MATERIALS AND METHODS

Thirty-eight completely edentulous subjects were included in the study. In each subject, soft tissue thickness was measured at 28 sites of the edentulous ridge by a single calibrated examiner. Intra-observer reliability was calculated with Intraclass Correlation Coefficients by measuring 10 subjects twice, after 1 week. Measurements (mm) were taken at the buccal, lingual, and crestal aspects of the ridge with a dedicated ultrasonic scanner. Repeated measures ANOVA and paired t-tests were used to compare the mean buccal, lingual, and crestal soft tissue thicknesses at each site. The Generalized Estimating Equations model was used to study the effects of age, sex, and race. Confidence level was set to 95%.

RESULTS

Mean tissue thickness ranged from 0.96  to 1.98 mm with a mean of 1.63 ± 0.25 mm. Intraclass Correlation Coefficients were > 0.97. No significant differences between buccal, crestal, and lingual sites were noted for the mandibular arch as well as at 4 sites on the maxillary arch (maxillary right second molar, maxillary right canine, maxillary left first premolar, maxillary left second molar). However, significant differences in soft tissue thickness were noted for all remaining maxillary sites. Race was found to be positively correlated with tissue thickness, with Black individuals showing a significantly greater thickness than White individuals at 4 sites (maxillary right first molar, maxillary left canine, mandibular right second premolar, mandibular right first molar). Age was found to be positively correlated with tissue thickness at 4 sites (maxillary left central incisor, maxillary left first molar, maxillary left second molar, mandibular left second premolar) and negatively correlated at 2 sites (mandibular right canine, mandibular right second molar). Female sex was positively (maxillary left second premolar, maxillary left second molar) and negatively (mandibular right canine) correlated, respectively, with tissue thickness at 3 sites. When data for anterior and posterior sites were respectively pooled, tissue thickness was significantly less at anterior sextant lingual and crestal sites, while no difference was seen for buccal sites.

CONCLUSION

Statistically significant differences for alveolar ridge mucosa thickness were found at several sites in the maxilla and between anterior and posterior sextants for lingual and crestal sites in the maxillary and mandibular arches. Tissue thickness differences were also noted for race with Black individuals showing greater tissue thickness at some sites. Age and sex did not show a clear effect on tissue thickness. Recorded differences in tissue thickness were however small and appear of uncertain clinical significance.

Revisiting the measurement of keratinized gingiva: a cross-sectional study comparing an intraoral scanner with clinical parameters

PURPOSE

The aim of this study was to investigate the relationships between gingival thickness (GT) and keratinized gingiva width (KGW), papilla height (PH), and crown ratio (CR) by employing transgingival probing and an intraoral scanner (IOS).

METHODS

This cross-sectional study examined 360 maxillary anterior teeth from 60 patients. GT was assessed using transgingival probing with an endodontic spreader. KGW, CR, and PH were measured using an IOS. One-way analysis of variance, the Student's t-test, and Spearman correlation coefficients were employed for statistical analysis.

RESULTS

Higher GT was significantly associated with thinner KGW in the central region (P=0.019). There was no statistically significant difference in GT between teeth (P=0.06). PH was lower in lateral teeth than in canines (P=0.047), with a PH of 2.99 mm in lateral teeth. The KGW was narrower in canines than in central teeth (P=0.007). A moderate correlation was observed between KGW and PH in the central region (P=0.01), while a weak negative correlation was found between KGW and CR (P=0.043).

CONCLUSIONS

A moderate negative correlation was found between GT and KGW, as well as between PH and KGW in central teeth. In contrast, a weak negative correlation existed between CR and KGW. The PH (2.99 mm) was lower in lateral teeth than in canines. The traditional paradigm, which suggests a positive correlation between KGW and GT, was re-evaluated by measuring KGW using an IOS.

Evaluation of Gingival Phenotype in the Early Transitional Dentition Phase in Children-Comparison of Three Non-Invasive Methods

Gingival phenotype (GP) is determined based on the thickness and width of the gingival tissue. An evaluation of GP is essential for adequate treatment planning and outcome monitoring, including orthodontic treatments in a paediatric population. The present study aimed to compare the reliability of the visual and TRAN methods with that of the ultrasound biometer measurements in the early transitional dentition phase. One hundred ninety three generally healthy, 7-year-old children were examined. An assessment of GP was performed by a paedodontist and a periodontist. The average thickness of the gingiva was 0.76 ± 0.36 mm, which was classified as a thin GP. The agreement between a visual assessment and the biometric ultrasound measurements reached the highest (94%) level when assessing a very thin GP (Spearman's rank correlation coefficient r = 0.37, p < 0.01). Similarly, 99% agreement in the diagnosis of a thin GP was recorded for the TRAN and ultrasound methods (Spearman's rank correlation coefficient r = 0.49, p < 0.001). In total, 86% of cases diagnosed as having a thick GP using the TRAN method turned out to be thin according to the ultrasound measurements. The dentist's specialization and professional experience in the assessment of GP were irrelevant (Spearman's rank correlation coefficient r = 0.49, p < 0.001). All methods tested in the present study were proven to be easy to perform and well accepted by the children. The visual assessment and TRAN methods, despite the fact that they enabled the diagnosis of a thin GP (crucial for treatment planning), cannot be recommended during the teeth replacement period. A misdiagnosis of thick GP may deprive a young at-risk patient of special supervision, which may develop into mucogingival deformities. A biometric ultrasound, although expensive, allows for reliable assessment of the gingiva thickness when needed.

Current landmarks for gingival thickness evaluation in maxillary anterior teeth: a systematic review

OBJECTIVES

To identify and report the current landmarks used for measuring gingival thickness (GT) in healthy maxillary anterior teeth.

MATERIAL AND METHODS

The protocol of this Preferred Reporting Items of Systematic Reviews and Meta-Analyses (PRISMA) 2020-compliant systematic review was registered in PROSPERO. A literature search was conducted to identify articles that met the eligibility criteria published up to 2022. The methods of assessing gingival thickness and the landmarks adopted on the studies were described. Primary outcomes were identified, and the frequency of reporting in the selected articles was calculated. Additionally, risk-of-bias assessments were performed for individual articles.

RESULTS

Fifty-eight articles (34 with low risk of bias and 24 with medium risk of bias) were selected. A total of 3638 individuals had their gingival thickness measured. Thirty-nine different landmarks were adopted in the studies. Fifty-six articles with 22 landmarks were included in the meta-analysis. A higher heterogeneity was found between the studies (GT ranged from 0.48 to 2.59 mm, mean GT 1.074; 95% CI: 1.024-1.104). The 3 most used landmarks were 2 mm from gingival margin (10 studies, mean GT 1.170 mm, 95% CI: 1.085-1.254), bone crest (9 studies, mean GT 1.01 mm; 95% CI: 0.937-1.083), and cemento-enamel junction (7 studies, mean GT 1.172 mm; 95% CI: 1.105, 1.239).

CONCLUSIONS

Within the limits of this study, a large heterogeneity in GT was found, and there was no consensus on the ideal landmark for GT measurement.

CLINICAL RELEVANCE

The landmark 2 mm from gingival margin, located at attached gingiva, can be used for GT measurement by clinical and image-based devices. This is an important step for a quantitative instead of a qualitative evaluation of phenotypes.

Comparison of the Effectiveness of the Ultrasonic Method and Cone-Beam Computed Tomography Combined with Intraoral Scanning and Prosthetic-Driven Implant Planning Method in Determining the Gingival Phenotype in the Healthy Periodontium

The aim of this study was to compare the effectiveness of two diagnostic methods: ultrasonic gingival thickness measurement (UGTM) and cone-beam computed tomography, intraoral scanning by computer-aided design technology with prosthetic-driven implant planning software (CBCT/CAD/PDIP) in determining the gingival phenotype (GP). Thirty periodontally healthy patients were examined. The ultrasonic device Pirop G^® with a frequency of 20 MHz and CBCT/CAD/PDIP were used to measure gingival thickness at upper canines and incisors in three points localized midbuccally, namely free gingival thickness (FGT), supracrestal (SGT) and crestal (CGT). Probing depth (PD), clinical attachment level (CAL) and width of keratinized tissue (WKT) were measured using periodontal probe. Intra-examiner and inter-examiner agreement and agreement between methods were evaluated using Bland-Altman analyses. Comparing both methods in the determination of SGT (bias = 0.17 mm, SD = 0.25 mm, p < 0.000) and CGT (bias = -0.45 mm, SD = 0.32 mm, p < 0.000) 95.0% and 95.6% agreement were found, respectively, and in the FGT range only 93.3% (bias = -0.45 mm, SD = 0.32 mm, p < 0.000). The presence of positive correlations between WKT and SGT was shown. A positive correlation between SGT and WKT confirms the purpose of measuring these parameters for the evaluation of the GP. Both the ultrasonic method and cone-beam computed tomography combined with intraoral scanning and prosthetic-driven implant planning method were useful in determining gingival phenotype, however, the ultrasonic method was more accurate for measuring GT.

A Comparative Evaluation of Dentogingival Tissue Using Transgingival Probing and Cone-Beam Computed Tomography

Background and Objective: Gingival biotype can be assessed using a variety of invasive and non-invasive procedures, such as direct probing, transgingival probing, ultrasound-guided approaches, and, for the more sophisticated, cone-beam computed tomography. The aim of this study was to evaluate gingival biotype in relation to transgingival probing and cone-beam computed tomography (CBCT). Materials and Methods: This study included a total of two hundred healthy individuals. Gingival thickness was assessed and measured from the right and left maxillary central incisor teeth using CBCT and transgingival probing of the attached gingiva. The measurements were analyzed with regard to tooth type (central incisor). Linear measurements for gingival biotype were measured using both methods. Correlations and differences between measurement methods were assessed. Results: The mean age of study participants was 32.49 ± 8.61 years. The radiographic measurements on CBCT were 1.34 ± 0.17 mm for the right central and 1.28 ± 0.21mm for the left central. The transgingival probing measurements were 1.31 ± 0.18 for the right central and 1.22 ± 0.21mm for the left central. Conclusion: As per the results of this study, there is a significant positive correlation between transgingival probing and CBCT measurements of gingival biotypes.

Agreement in measurements of ultrasonography-derived periodontal diagnostic parameters among multiple raters: A diagnostic accuracy study

OBJECTIVE

The aim of this study was to investigate the reproducibility of measurements of ultrasound-derived periodontal diagnostic parameters (PDPs) among raters.

STUDY DESIGN

Periodontists with various degrees of ultrasound experience were invited to measure 3 PDPs: soft tissue height (STH), soft tissue thickness (STT), and crestal bone thickness (CBT) on 37 human periodontal ultrasound scans acquired at the midfacial site of non-molar maxillary teeth. After an online training session and a 2-week calibration exercise, intraclass correlation coefficients (ICCs) were estimated with mixed linear regression models. The interrater mean absolute differences (MADs) were calculated among the raters and between the raters and a reference standard examiner.

RESULTS

Thirteen raters participated in the study. MADs among the 13 raters were 0.18 mm (STH), 0.16 mm (STT), and 0.12 mm (CBT). ICC values for STH, STT, and CBT were 0.83, 0.77, and 0.76, respectively. The MADs between the raters and the reference standard were 0.23 mm (STH), 0.19 mm (STT), and 0.14 mm (CBT). Survey results showed that ultrasound has diagnostic value and is generally easy to learn.

CONCLUSIONS

Within the limitations of this study, good agreement was observed among ultrasound learners with various degrees of experience when measuring ultrasound-derived PDPs.

Gingival Phenotype Changes and the Prevalence of Mucogingival Deformities during the Early Transitional Dentition Phase-A Two-Year Longitudinal Study

Thin gingival phenotype (GPh) may contribute to periodontal tissue breakdown and recession development. Thus, the early identification of thin GPh in children can allow proper preventive care and the identification of children at risk during orthodontic treatment. The present long-term study aimed to monitor GPh changes, i.e., thickness (GT) and width of attached gingiva (AGW) during the early transitional dentition phase, as well as its potential associations with the mucogingival deformities. Materials and Methods: 83 systematically healthy children were examined twice with an interval of 2 years. Probing depth, GT and AGW at mandibular incisors, vestibular depth, type of lower lip frenum attachment and mucogingival defects were recorded. Results: 95.2% of participants at baseline and 93.9% at 2-year examination expressed thin GPh. During the transition from the deciduous to permanent dentition, GT and AGW declined, but the GT of permanent incisors already erupted at the baseline examination increased in the observation period. Conclusions: Gingival phenotype undergoes changes in the early transitional dentition phase. In spite of the thin gingival phenotype, only single pseudo-recessions and primary shallow vestibule were noticed.

Methods to assess tooth gingival thickness and diagnose gingival phenotypes: A systematic review

OBJECTIVE

Measurement of the periodontal soft tissue dimension is crucial for clinical decision-making and aesthetic prognosis. However, the effectiveness of different measuring methods remains unclear. This systematic review aimed to explore the diagnostic accuracy of two non-invasive methods (namely CBCT and ultrasound) for gingival thickness measurement at different tooth positions.

MATERIALS AND METHODS

A systematic search was performed using PubMed (including Medline), PubMed Central, OVID, Cochrane Library, LILACS and OpenGrey. Studies focusing on comparisons between CBCT, ultrasound and direct transgingival probing were included. The means, SDs and correlation coefficients with 95% confidence intervals were extracted and analyzed using Review Manager and R software.

RESULTS

Twelve studies were selected. No significant difference was found between CBCT measurement and transgingival probing in the anterior and posterior dentition, and a moderate correlation was observed between these two methods (r = 0.41). A weak correlation was found between ultrasound measurement and transgingival probing (r = 0.32), and a slight but statistically significant difference was found when comparing ultrasonic devices and transgingival probing in the posterior area.

CONCLUSION

CBCT can be considered a relatively reliable method for gingival thickness measurement in both the anterior and posterior areas compared with direct probing. Ultrasonic devices provide limited accuracy in the posterior area but are relatively comparable with direct clinical assessments in the anterior area.

CLINICAL SIGNIFICANCE

Measurement location may affect the diagnostic accuracy and repeatability of gingival thickness measurements. Appropriate method selection in different clinical scenarios is crucial to aesthetic outcome prediction and decision-making.

Are colored periodontal probes reliable to classify the gingival phenotype in terms of gingival thickness?

BACKGROUND

This cross-sectional study assessed the potential of colored periodontal probes (CPP) to classify gingival phenotype in terms of gingival thickness (GT).

METHODS

Buccal GT in 3 anterior teeth in each of 50 patients was measured by transgingival sounding and classified by 3 different methods by 8 examiners. Specifically, the diagnostic potential of visual judgement and transparency of a standard periodontal probe (SPP) to discriminate thin and thick gingiva, and of CPP to discriminate thin, medium, thick, or very thick gingiva was assessed.

RESULTS

GT ranged from 0.57-2.37mm. Using CPP resulted in a medium judgement in 87% of the cases, on average, and only between 1-10 cases/examiner were judged as thick or very thick. Considering 1mm GT as relevant cut-off value, all methods showed a high positive predictive value (≥0.82) to identify thick cases, but also a high false omission rate (≥0.73) indicating that many cases classified as thin were actually thick. Further, 88% of the cases being ≤1mm, were not classified as thin with CPP; this was inferior to SPP, for which, however, still 64% of the cases being ≤1mm thick were wrongly classified. The highest, yet moderate agreement among examiners was achieved by SPP (κ = 0.427), while visual judgement and CPP showed only fair (κ = 0.211) and slight agreement (κ = 0.112), respectively.

CONCLUSION

Using CPP resulted in most of the cases in a medium judgement. It seems that CPP cannot distinctly discriminate between "thick" and "very thick" cases and fails to capture the thin high-risk cases. This article is protected by copyright. All rights reserved.

Three-dimensional quantitative measurement of buccal augmented tissue with modified coronally advanced tunnel technique and de-epithelialized gingival graft: a prospective case series

Background

The aim of this study is to investigate three-dimensional quantitative analysis of buccal augmented tissue alterations after surgery using a modified coronally advanced tunnel (MCAT) technique combined with a de-epithelialized gingival graft (DGG) within 1 year post-op, based on intraoral scanning.

Methods

25 Cairo class I gingival recession defects were treated using an MCAT technique with DGG. Digital impressions were taken using an intraoral scanner at baseline, 2 weeks, 6 weeks, 3 months, and 1 year after the surgery. Three-dimensional quantitative measurements within 1 year were analyzed for buccal augmented tissue after surgery, including postoperative gingival height gain (GHG), area gain (GAG), volume gain (GVG) and mean thickness (GMT) of region of interest, as well as the tissue thickness change at 1, 2, and 3 mm (TTC1, TTC2, and TTC3) apical to the cemento-enamel junction.

Results

Postoperative GHG, GAG, GVG, and GMT were distinctly encountered at 2 weeks post-op, then gradually decreased. At 1 year, GHG, GAG, GVG, and GMT were 2.211 ± 0.717 mm, 7.614 ± 2.511 mm², 7.690 ± 4.335 mm³ and 0.965 ± 0.372 mm, respectively. Significant decreases were recorded between 6 weeks and 1 year in terms of GHG, GAG, and GVG. The GMT was sustained after 6 weeks with an increase of nearly 1 mm at 1 year. TTC1 and TTC2 yielded thicker tissue change than TTC3.

Conclusions

Three-dimensional quantitative measurements taken via intraoral scanning showed that buccal augmented tissue acquired via MCAT with DGG tends to be stable after 3 months post-op. Digital measurement can be applied in periodontal plastic surgery as a clinically feasible and non-invasive evaluation method for achieving volumetric outcomes.

Trial registration

This study was retrospectively registered in the Chinese Clinical Trial Registry: ChiCTR1900026768. Date of registration: 21/10/2019.

Cervical tooth anatomy considerations for prefabricated anatomic healing abutment design: A mathematical formulation

STATEMENT OF PROBLEM

A custom emergence profile offers the ideal horizontal dimensions for an anatomic healing abutment. However, developing such an emergence profile can be a time-consuming and complex process.

PURPOSE

The purpose of this study was to develop a mathematical formula defining horizontal cervical tooth geometry to design prefabricated, tooth-specific, healing abutments.

MATERIAL AND METHODS

Cone beam computed tomography (CBCT) horizontal cross sections of 989 teeth on 54 participants were measured. For anterior and premolar teeth, 2 perpendicular ellipses were fitted onto the cervical tooth cross section that was defined by 3 parameters. The lingual ellipse followed the lingual outline of the tooth, and its diameter was the largest mesiodistal diameter of the tooth (parameter "a"); its buccolingual radius became parameter "b." The buccal ellipse was perpendicular to the lingual ellipse and followed the buccal outline of the tooth. The buccolingual radius of the smaller ellipse became parameter "c." For molars, the first ellipses followed the mesial outline of the tooth, and its larger diameter (parameter "a") matched the largest buccolingual diameter of the tooth. Its smaller radius became parameter "h1." The second ellipse was parallel to the first ellipse and followed the distal outline of the tooth. Its larger diameter became parameter "b", and its mesiodistal diameter became parameter "h2". Statistical differences between parameters were evaluated by the linear mixed model (α=.05 after Bonferroni adjustment). Pairwise comparisons were made separately for each parameter of the molars and separately for each parameter for the anterior teeth plus premolars. Teeth were put into the same parameter cluster if no significant differences were found between them for a specific parameter. If neither parameter (4 for molars and 3 for the other teeth) was different for 2 teeth, they were put into the same abutment cluster. The abutment clusters determined the type of anatomic healing abutment. The areas were calculated from the developed mathematical formula by using the parameters. In addition, cervical areas of 106 randomly chosen teeth were measured directly with a photo-editing software program. A computer algorithm was used to select 5 CBCT scans from the 54 by using the simple randomization method. The agreement between the 2 methods was evaluated by Bland-Altman analysis.

RESULTS

The lower and upper limits of agreement between the 2 methods were -8.57 and 7.36 mm², respectively, with no bias (-0.61 mm², P=.224). Significant differences were found between most parameters among the 14 tooth types (P<.001). Based on the parameters, 12 specifically distinct clusters were defined. Two tooth types were pooled into 1 abutment cluster: the maxillary first and second premolars and the mandibular first and second molars.

CONCLUSIONS

The cervical tooth cross section can be accurately defined by combining 2 elliptical elements. A comprehensive array of tooth specific emergence profiles can be provided by just 12 different prefabricated abutments, designed as per the recommended parameters.

Non-invasive evaluation of labial gingival and alveolar crest thickness in the maxillary anterior teeth region by 15-MHz B-mode ultrasonography

Background

Knowledge of gingival thickness (GT) and alveolar crest thickness (ACT) is essential when performing surgical and non-surgical procedures in the maxillary anterior teeth region. This study aimed at evaluating the GT and ACT in the maxillary anterior teeth region using 15-MHz B-mode Ultrasonic (US).

Methods

A total of 300 teeth from 50 healthy participants, comprising 25 women and 25 men, aged between 18 and 35 years were analyzed. We measured labial periodontal tissue structures of maxillary anterior teeth, including GT and ACT, at 3 mm apical to the gingival margin (GT3) and the crestal level, respectively. The GT and ACT measurements were correlated.

Results

The mean labial GT3 of the maxillary central incisors, lateral incisors, and canines were 1.24 ± 0.03 mm, 1.21 ± 0.03 mm and 1.11 ± 0.03 mm, respectively. Canine GT3 was significantly thin than those in the central and lateral incisors (P < 0.05). With regards to labial ACT, we recorded 0.79 ± 0.03 mm, 0.76 ± 0.02 mm and 0.73 ± 0.02 mm for maxillary central incisors, lateral incisors and canines, respectively. There were no significant differences in ACT of maxillary anterior teeth (P > 0.05). GT3 of men was greater than that of women (P < 0.05). In addition, GT and ACT were positively correlated (r = 0.32, P < 0.01).

Conclusion

15-MHz B-mode US is an effective tool for measuring labial GT and ACT of anterior teeth. There are sex-associated differences in GT3 and the correlation between the GT3 and ACT of anterior teeth is moderately positive.

Epinephrine penetrates through gingival sulcus unlike keratinized gingiva and evokes remote vasoconstriction in human

Background

It has been demonstrated in non-oral tissues that the locally evoked vasoconstriction could elicit remote vasoconstriction. This study aimed to investigate the spreading vasoconstrictor effects of epinephrine in the gingiva.

Methods

Gingival blood flow (GBF) was measured by laser speckle contrast imager in 21 healthy volunteers. In group A, two wells were fabricated from orthodontic elastic ligature and placed 2 mm apically to the free gingival margin at the mid buccal line of 12 (test side) and 21 (control side) teeth. The GBF was measured in the wells and tightly apical, coronal, distal and mesial to the wells. In group B, the wells were made on the buccal surface of the same teeth, including the gingival sulcus. Four regions were selected for measurement from the gingival margin reaching the mucogingival line (coronal, midway1, midway2 and apical). After the baseline recording, 3 µg epinephrine was applied into the test, and physiological saline into the control well. The GBF was recorded for 14 min. The gingival thickness was measured with a PIROP Ultrasonic Biometer.

Results

In group A, the GBF did not increase or decrease after the application of epinephrine. In group B, the GBF significantly decreased in all regions of the test side and remained low for the observation period. The vasoconstriction appeared with delays in more apical regions (at min 1 in the coronal and the midway1, at min 2 in the midway2, at min 4 in the apical region). Similarly, the amount of the decrease at 14 min was the largest close to sulcus (− 53 ± 2.9%), followed by the midway1 (− 51 ± 2.8%) and midway2 (− 42 ± 4.2%) and was the lowest in the apical region (− 32 ± 5.8%). No correlation was found between GBF and gingival thickness.

Conclusion

Epinephrine could evoke intense vasoconstriction propagating to the mucogingival junction, indicating the presence of spreading vasoconstriction in the human gingiva. The attached gingiva is impermeable to epinephrine, unlike the gingival sulcus.

This trial was registered in ClinicalTrials.gov titled as Evidence of Spreading Vasoconstriction in Human Gingiva with the reference number of NCT04131283 on 16 October 2019. https://clinicaltrials.gov/show/NCT04131283

Three-Dimensional Bone Block Planning for Mandibular Sagittal Bone Defect Reconstruction

Bone defects seen in severe sagittal discrepancies between the maxilla and mandible do not solely qualify for orthodontic treatment. An interdisciplinary approach with the aid of a surgical, orthodontic, and periodontal team should be implemented in the treatment of such cases. Despite the use of standard treatment methods, the therapy is always planned and carried out individually for each patient. The surgical treatment of bone defects in the area of the jawbones is associated with a number of potential complications. Regenerative medicine, which has already been practiced in reconstructive surgery, is now gradually receiving more attention in the treatment of orthognathic defects. We developed a method for the reconstruction of the alveolar bone in the sagittal dimension using 3D allogenic graft blocks, as a preparing feature in the orthodontic treatment of borderline cases or as a treatment option for complications arising during general orthodontic treatment.

In Vivo Evaluation of Periodontal Phenotypes Using Cone-Beam Computed Tomography, Intraoral Scanning by Computer-Aided Design, and Prosthetic-Driven Implant Planning Technology

BACKGROUND Two clinical parameters, the gingival thickness (GT) and the width of keratinized tissue (WKT), describe the gingival phenotype, which is defined as the 3-dimensional volume of the gingiva. The periodontal phenotype additionally includes the thickness of the labial plate of the alveolar crest (TLPAC). MATERIAL AND METHODS Thirty patients with healthy periodontium on the upper canines and incisors underwent measurements for crestal, supracrestal, free gingival thickness (FGT), the alveolar crest-gingival margin (AC-GM), alveolar crest-cementoenamel junction distance, and the TLPAC at 2, 4, and 8 mm apically from the edge of the alveolar crest using cone-beam computed tomography (CBCT) with computer-aided design and prosthetic-driven implant planning technology. For each tooth, the gingival and periodontal phenotype was evaluated on the basis of the gingival thickness, width of keratinized tissue (WKT), and TLPAC measurements. Each patient's periodontal phenotype was evaluated according to the coronal width/length ratio of both the upper central incisors. RESULTS The dentogingival units had varying average values for the 3 periodontal phenotypes (thin phenotype: FGT 0.65±0.06 mm, WKT 4.85±1.18 mm, AC-GM 3.17±0.64 mm, TLPAC2 0.66±0.28 mm; medium phenotype: FGT 0.87±0.07 mm, WKT 5.49±1.23 mm, AC-GM 3.36±0.65 mm, TLPAC2 0.76±0.37 mm; and thick phenotype: FGT 1.20 mm, WKT 6.00 mm, AC-GM 3.90 mm, TLPAC2 0.90 mm). Positive correlations were seen among WKT, FGT, AC-GM, and TLPAC2. CONCLUSIONS Positive correlations between the FGT and WKT, and the AC-GM distance confirm that measurements using CBCT with computer-aided design and prosthetic-driven implant planning technology can evaluate the gingival phenotype and TLPAC2 for the periodontal phenotype.

Periodontal phenotype: A review of historical and current classifications evaluating different methods and characteristics

OBJECTIVE

To review the historical and current periodontal phenotype classifications evaluating methods and characteristics. Moreover, to identify and classify the methods based on periodontal phenotype components.

OVERVIEW

Several gingival morphology studies have been frequently associated with different terms used causing confusion among the readers. In 2017, the World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions recommended to adopt the term "periodontal phenotype". This term comprises two terms, gingival phenotype (gingival thickness and keratinized tissue width) and bone morphotype (buccal bone plate thickness). Furthermore, gingival morphology has been categorized on "thin-scalloped", "thick-scalloped" and "thick-flat" considering the periodontal biotype. However, by definition, the term phenotype is preferred over biotype. Periodontal phenotype can be evaluated through clinical or radiographic assessments and may be divided into invasive/non-invasive (for gingival thickness), static/functional (for keratinized tissue width), and bi/tridimensional (for buccal bone plate thickness) methods.

CONCLUSIONS

"Thin-scalloped," "thick-scalloped," and "thick-flat" periodontal biotypes were identified. These three periodontal biotypes have been considered in the World Workshop but the term periodontal phenotype is recommended. Periodontal phenotype is the combination of the gingival phenotype and the bone morphotype. There are specific methods for periodontal phenotype evaluation.

CLINICAL SIGNIFICANCE

The term periodontal phenotype is currently recommended for future investigations about gingival phenotype and bone morphotype. "Thin-scalloped," "thick-scalloped," and "thick-flat" periodontal phenotypes can be evaluated through specific methods for gingival thickness, keratinized tissue width, and buccal bone plate thickness evaluation.

Evidence of spreading vasodilation in the human gingiva evoked by nitric oxide

BACKGROUND AND OBJECTIVE

Spreading vasodilation is an important means of increasing local blood flow effectively during increased metabolic demands or in case of vascular injury. Our aim was to develop a technique proving the presence of spreading vasodilation in the human keratinized gingiva.

METHODS

Local vasodilation was evoked by the application of nitric oxide (NO) donor nitroglycerin into a well, fixed 2 mm above the marginal gingiva, in 20 subjects with healthy periodontal tissue. Either 1 or 8 mg/mL nitroglycerin solutions were dropped into the test well at the upper right second incisor, and saline was applied into the control well at the upper left first incisor. The gingival blood flow (GBF) was recorded for 15 minutes by a laser speckle contrast imager below the well and in the surrounding area in the mesial, distal, apical and coronal directions. Gingival thickness was measured by an ultrasonic biometer.

RESULTS

Peak GBF increase was similar after 1 mg/mL and after 8 mg/mL nitroglycerin application in the well (51% ± 12% vs 42% ± 8%) and in the apical region (33 ± 9% vs 55% ± 13%). While the lower dose of nitroglycerin increased GBF only in the apical region around the well, the higher dose induced significant elevations in all surrounding regions, with apical prominence. Hyperaemia lasted 10-14 minutes in the low-dose group whereas it extended beyond the observation period in the high-dose group. Neither the baseline nor the NO-induced peak GBF were correlated with gingival thickness.

CONCLUSION

The role of the direct effect of NO in the regulation of perfusion was demonstrated in the human gingiva as well as the propagation of local vasodilation to distant, especially apical areas, probably by the mechanism of flow-mediated dilation. This mechanism may have a clinical importance for flap survival or wound healing.