Classification of periodontal biotypes with the use of CBCT. A cross-sectional study

Relationship Between Cone-Beam CT Evaluation and Clinical Evaluation Before and After Orthodontic Treatment and the Rate of Gingival Recession: A Systematic Review

A systematic review was conducted to investigate the correlation between gingival recession and orthodontic treatment analysis using cone-beam CT (CBCT) dental images to provide an accurate overview of the factors that can influence gingival recession. The literature was searched across several databases (PubMed, Scopus, Web of Science, etc.) for studies using CBCT dental images. Four full-text articles describe how CBCT is used to evaluate gingival recession during orthodontic treatment. The Risk-of-Bias VISualization tool was used to assess the risk of bias. In dentistry, CBCTs are used for various imaging modalities. An accurate assessment of gingival recession was made using CBCT. There were only 35 (22.5%) cases of retraction of the gingival margin after orthodontic treatment. In most studies, various types of malocclusions were treated successfully with fixed orthodontic treatment without gingival recession. Among the studies, 50% had a low risk of bias in all four areas, while one study (25%) had an unclear risk of bias. Only one study (25%) had a high risk of bias. CBCT systems have been extensively studied to show their wide application potential in preventing gingival recession. CBCT systems should be further investigated to address limitations associated with methodology and application. Dental applications of CBCT can be enriched by overcoming these challenges.

Gingival phenotype determination: Cutoff values, relationship between gingival and alveolar crest bone thickness at different landmarks

Background/purpose

Gingival phenotype (GP) has been reported to influence the treatment planning and clinical outcomes in several dental specialties. This study aimed to investigate optimal cutoff values for gingival thickness (GT) measurement at different landmarks to determine GP. The correlations between GT and bone thickness (BT) of buccal alveolar crest were also analyzed.

Materials and methods

A total of 600 teeth were included. GP was clinically determined by the transparency of a periodontal probe through the gingival margin (TRAN). Measurements for free gingival thickness (GT1), cementoenamel junction gingival thickness (GT2), supracrestal gingival thickness (GT3), subcrestal 1 mm gingival thickness (GT4) and BT at 1, 3 mm apical from the alveolar crest edge (BT1 and BT2) were assessed on cone-beam computed tomography (CBCT) images. Spearman's correlation coefficient was used to evaluate correlations between GT and BT.

Results

The optimal cutoff values of GT using CBCT method to discriminate GP were 0.75 mm for GT1, 0.85 mm for GT2, 1.15 mm for GT3 and 0.45 mm for GT4. There was significantly positive correlation between GT and BT at all levels (r: 0.375-0.903). The correlations between GT3 and BT (r: 0.789-0.903) were strong, while correlations between GT4 and BT were weak (r: 0.375-0.467).

Conclusion

The optimal cutoff values of gingival thickness using CBCT method to discriminate gingival phenotype at each gingival landmark were determined. The supracrestal gingival thickness might be an indicator of buccal alveolar crest bone thickness, which could provide valuable perspectives on clinical diagnosis, treatment planning and decision-making.

Clinical and computed tomographic evaluations of periodontal phenotypes in a Chinese population: a cross-sectional study

OBJECTIVES

To investigate the diagnostic value of probe transparency related to gingival thickness (GT) and keratinized gingival width (KGW) at individual and site levels and explore the relationship of buccal bone plate thickness (BT) with GT and KGW.

MATERIALS AND METHODS

A total of 1,606 teeth from 167 patients with periodontally healthy maxillary anterior region were included. GT was measured with probe transparency and transgingival probing. KGW was measured directly. BTs were assessed at the level 1 mm apical to the alveolar crest (BT1) and midpoint of the root (BT2) and evaluated at individual and tooth levels along with their mutual associations.

RESULTS

The prevalence of thick gingiva was 53% with probe transparency measurement and 51% with transgingival probing. The cutoff gingival thickness was 0.8 mm, which correlated moderately with a Cohen's kappa of 0.386. The mean GT, KGW, and BTs (BT1 and BT2) in the maxillary anterior region were 0.97 ± 0.46, 5.51 ± 1.62, 0.85 ± 0.31, and 0.79 ± 0.32 mm, respectively. GT and KGW correlated mildly (r = 0.261), and GT and BTs correlated moderately (BT1: r = 0.298; BT2: r = 0.338). GT and BTs differed significantly between men and women and among different tooth sites.

CONCLUSIONS

GT and BTs correlated positively in the maxillary anterior region and varied within and among individuals. Sex was a factor influencing the gingival phenotype and bone morphotype.

CLINICAL RELEVANCE

GT measured with transgingival probing, with a cutoff of 0.8 mm, could serve as an objective measure to distinguish different gingival phenotypes.

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.

Gingival landmarks and cutting points for gingival phenotype determination: A clinical and tomographic cross-sectional study

BACKGROUND

This cross-sectional study assessed the role of gingival landmarks (GLs) and cutting points (CPs) for gingival phenotype (GP) determination.

METHODS

Six maxillary anterior teeth (70 subjects) were evaluated using soft tissue cone-beam computed tomography (ST-CBCT). Gingival thickness was measured at different GLs: 1) tissue zone (gingival margin [GM], 1 and 2 mm apical to GM, cemento-enamel junction, above the bone crest); 2) bone zone (buccal bone crest [BBC], 1, 2, and 3 mm apical to BBC). CPs of 0.6, 0.8, 1.0, 1.2, and 1.5 mm were used to discriminate between thin and thick GP. The clinical determination of GP was made based on transparency of the periodontal probe (TRAN).

RESULTS

The prevalence of thin and thick GP depended on the GL and CP. Considering the CP (1 mm), thin GP at the tissue zone ranged from 99% at the GM to 10.2% above the bone crest. In the bone zone, thick GP ranged from 28% at the BBC to 6% at 3 mm apical to the BBC. The predictability of a correct assessment of GP by TRAN compared with ST-CBCT was influenced by the GLs and CPs. A slight agreement (kappa <0.2) and low accuracy (area under the curve <0.7) were found between methods.

CONCLUSIONS

The determination of thin and thick GPs is related to the gingival landmarks and CPs. Further studies are required for a well-defined treatment protocol considering different gingival landmarks in tissue and bone zones. An ST-CBCT may be useful for this purpose.

Assessment of the relationship between tooth inclination and gingival and alveolar bone dimensions using computed tomography of the maxillary anterior teeth: a cross-sectional study

OBJECTIVE

The present study aimed to investigate the relationship between tooth inclination and gingival and bone dimensions in maxillary anterior teeth.

METHODS

This cross-sectional study included cone-beam computed tomography (CBCT) images of 160 maxillary anterior teeth (30 individuals). Tooth inclination, gingival and bone thickness, and distances from cementoenamel junction to alveolar bone crest and gingival margin were measured in the labial surface. The correlations were analyzed using Pearson and partial correlation tests (p≤0.05).

RESULTS

In the central incisors, tooth inclination was positively and significantly related to apical bone thickness (R = 0.34, p= 0.001). In the canines, tooth inclination was negatively and significantly related to cervical bone thickness (R = - 0.34, p= 0.01) and positively associated to apical bone thickness (R = 0.36, p= 0.01) and to gingival margin-cementoenamel junction distance (R = 0.31, p= 0.03). In the lateral incisors, tooth inclination was not associated with gingival or bone dimensions.

CONCLUSIONS

In the central incisors, the greater the labial tooth inclination, the greater is the apical bone thickness. In the canines, the greater the labial tooth inclination, the smallest is the cervical bone thickness, the greater is the apical bone thickness, and the greater is the gingival margin. Gingival and bone dimensions should be assessed when planning orthodontic treatment involving buccal movement of central incisors and canines.

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.

Assessment of the relationship between labial gingival thickness and the underlying bone thickness in maxillary anterior teeth by two digital techniques

This study aimed to noninvasively assess the relationship between the labial gingival thickness (GT) and the underlying bone thickness (BT) of maxillary anterior teeth by two digital techniques. A total of 30 periodontally healthy participants with 172 maxillary anterior teeth were enrolled. GT and BT were measured at 2, 4 and 6 mm apical to the cemento-enamel junction (CEJ) by two digital techniques: M1—cone-beam computed tomography (CBCT) and M2—digital intraoral scanning (DIS) combined with CBCT. The Pearson's correlation coefficient was calculated to determine the correlation between GT and BT. A significant negative correlation was identified between GT and BT at 2 mm apical to the CEJ for central incisors (CI), lateral incisors (LI), and canines (CA) both by M1 and M2, while a weak negative correlation at 4 mm apical to the CEJ was observed by M1 for CA. No significant correlation was found at other sites by both M1 and M2. The labial BT was < 1 mm in most cases (85% of CI; 97% of LI; and 90% of CA). Within the limitation of this study, it was concluded that GT and BT seemed to be negatively correlated at 2 mm apical to the CEJ. Therefore, caution is warranted when implant restoration at the esthetic area of the anterior teeth.

Evaluation of the association between gingival phenotype and alveolar bone thickness: A systematic review and meta-analysis

OBJECTIVE

To conduct a systematic review and meta-analysis of studies that evaluated the association between gingival phenotype (GP) and the underlying alveolar bone thickness (ABT).

DESIGN

An electronic search was performed in PubMed, Embase, Scopus, ProQuest, and Web of Science. The following inclusion criteria were applied: English original studies that compared the ABT in periodontally healthy patients presenting thin versus thick GPs. Studies that evaluated the correlation between gingival thickness (GT) and ABT were also included. Pooled mean difference (95% confidence interval) was estimated using random-effects maximum likelihood model meta-analysis.

RESULTS

From a total of 1427 retrieved articles, 17 were included. The majority of eight studies that compared the ABT between thick and thin GPs, reported a significantly greater ABT associated with a thick phenotype. Based on the meta-analysis results of six studies, the mean difference between the two phenotypes (0.33 mm) was statistically significant (P < 0.01). The majority of ten studies that investigated the correlation between GT and ABT evidenced a significant positive correlation (r = 0.11 -0.49). The association was more evident in the crestal areas and decreased toward the apex.

CONCLUSIONS

There is contradictory evidence concerning the correlation between soft and hard tissue thickness; however, the meta-analysis revealed a significantly thicker alveolar plate in the presence of a thick phenotype. Since the evaluation of GP could be simply performed using a periodontal probe, such a relationship could provide clinical perspective at the initial examination. This is particularly beneficial in procedures affecting periodontal structures, including immediate implant placement and orthodontic treatments.

Relationship between anterior maxillary tooth sagittal root position and periodontal phenotype: a clinical and tomographic study

OBJECTIVES

To evaluate the relationship between the tomographic sagittal root position (SRP) of maxillary anterior teeth and periodontal phenotype (PP).

MATERIAL AND METHODS

Seventy volunteers (420 teeth) were evaluated. Clinical and photographic exams included the evaluation of gingival phenotype (GP) by transparency of the periodontal probe, keratinized tissue width (KTW), gingival architecture, tooth shape, and papilla height (PH). Soft tissue tomographic scan (ST-CBCT) measurements included the SRP classification, GP, gingival thickness in the tissue zone (GT-TZ) and in the bone zone (GT-BZ), buccal bone thickness (BBT), and the distances from the gingival margin and from cementoenamel junction to the buccal bone crest (GM-BBC and CEJ-BBC). Kruskal-Wallis test and a linear regression analysis model were used.

RESULTS

The frequency of SRP over the 420 teeth was 65.2% (class I), 9.3% (class II), 0.7% (class III), and 24.8% (class IV). Linear regression analysis showed that SRP is related to PP (p < 0.05). Significantly different measurements of PP parameters were found in SRP classes. The higher and lower GT and BBT were found in classes II and I, respectively. Class IV presented the highest KTW, PH, CEJ-BBC, and GM-BBC. Central incisors (CI) classes I and II were most frequently square-shaped, while 89% of CI Class IV were triangular-shaped.

CONCLUSION

The SRP of maxillary anterior teeth is related to periodontal phenotype.

CLINICAL RELEVANCE

Clinical and ST-CBCT individual analysis of PP and SRP may be helpful for an esthetic and functional treatment plan based on soft and hard tissue thickness and tooth positioning.

Efficacy of bone-substitute materials use in immediate dental implant placement: A systematic review and meta-analysis

OBJECTIVE

To assess the efficacy of using a bone substitute material (BSM) in the fixture-socket gap in patients undergoing tooth extraction and immediate implant placement.

MATERIALS AND METHODS

MEDLINE, EMBASE, and CENTRAL databases were searched for randomized controlled trials (RCTs). RCTs were screened for eligibility, and data were extracted by two authors independently. Risk of bias (ROB) was assessed using Cochrane's ROB tool 2.0. Primary outcomes were implant failure, overall complications, and soft-tissue esthetics. Secondary outcomes were vertical buccal bone resorption, vertical interproximal bone resorption, horizontal buccal bone resorption, and mid-buccal mucosal recession. Meta-analysis was performed using random-effects model with generic inverse variance weighing. GRADE was used to grade the certainty of the evidence.

RESULTS

After screening 19 544 potentially eligible references, 20 RCTs were included in this review, with a total of 848 patients (916 sites). Most included RCTs were deemed of some concerns (53%) or at low (38%) risk of bias, except for overall complications (high ROB). Implant failure did not differ significantly RR = 0.92 (confidence intervals [CI] 0.34 to 2.46) between using a BSM compared with not using a BSM (NoBSM). BSM use resulted in less horizontal buccal bone resorption (MD = -0.52 mm [95% CI -0.74 to -0.30]), a higher esthetic score (MD = 1.49 [95% CI 0.46 to 2.53]), but also more complications (RR = 3.50 [95% CI 1.11 to 11.1] compared with NoBSM. Too few trials compared types of BSMs against each other to allow for pooled analyses. The certainty of the evidence was considered moderate for all outcomes except implant failure (low), overall complications (very low), and vertical interproximal bone resorption (very low).

CONCLUSION

BSM use during immediate implant placement reduces horizontal buccal bone resorption and improves the periimplant soft-tissue esthetics. Although BSM use increases the risk of predominantly minor complications.

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.

Clinical and tomography evaluation of periodontal phenotypes of Brazilian dental students

BACKGROUND

The periodontal phenotype (PP) plays an important role in the function, esthetics, and maintenance of periodontal health and has a great influence in periodontal, restorative, and dental implant therapies.

AIM

The aim of this study was to conduct a clinical evaluation of the PP and its morphometric variations through the cone-beam computed tomography (CBCT), from dentistry students with periodontal health.

MATERIALS AND METHODS

Sixty students were examined, and the clinical parameters of probing depth and width of keratinized tissue (WKT) in the upper anterior segment were accessed. The gingival thickness was evaluated as thick or thin, through the translucency of the periodontal probe through the marginal gingiva. By convenience sample, 13 students were selected to assess bone thickness and gingival thickness and biological width through the previous CBCT examination.

RESULTS

The most prevalent PP, according to the classification by De Rouck et al., was the thick scalloped (55%), and using the classification of Kao and Pasquinelli, the thick PP was most common (73,3%). The thick PP in both the classifications was more prevalent in both genders and the WKT was significantly higher in the thick-flat scalloped PP. The bone thickness was always greater than the gingival thickness in CBCT examinations both in the measures 1 mm and 3 mm above the bone crest. The average of the biological width measurement was 2.02 mm.

CONCLUSIONS

The thick PP was most prevalent in the sample studied, and the gingival thickness was always thinner than the bone thickness in the measures evaluated.

Correlation analysis of periodontal tissue dimensions in the esthetic zone using a non-invasive digital method

Purpose

Direct intraoral scanning and superimposing methods have recently been applied to measure the dimensions of periodontal tissues. The aim of this study was to analyze various correlations between labial gingival thickness and underlying alveolar bone thickness, as well as clinical parameters among 3 tooth types (central incisors, lateral incisors, and canines) using a digital method.

Methods

In 20 periodontally healthy subjects, cone-beam computed tomography images and intraoral scanned files were obtained. Measurements of labial alveolar bone and gingival thickness at the central incisors, lateral incisors, and canines were performed at points 0–5 mm from the alveolar crest on the superimposed images. Clinical parameters including the crown width/crown length ratio, keratinized gingival width, gingival scallop, and transparency of the periodontal probe through the gingival sulcus were examined.

Results

Gingival thickness at the alveolar crest level was positively correlated with the thickness of the alveolar bone plate (P<0.05). The central incisors revealed a strong correlation between labial alveolar bone thickness at 1 and 2 mm, respectively, inferior to the alveolar crest and the thickness of the gingiva at the alveolar crest line (G0), whereas G0 and labial bone thickness at every level were positively correlated in the lateral incisors and canines. No significant correlations were found between clinical parameters and hard or soft tissue thickness.

Conclusions

Gingival thickness at the alveolar crest level revealed a positive correlation with labial alveolar bone thickness, although this correlation at identical depth levels was not significant. Gingival thickness, at or under the alveolar crest level, was not associated with the clinical parameters of the gingival features, such as the crown form, gingival scallop, or keratinized gingival width.

Long-term evaluation of lower incisors gingival recessions after orthodontic treatment

AIM

The development of gingival recessions has been associated with orthodontic treatment; however, a clear etiology is still unknown. The aim of the present study was to further clarify potential association between the development of labial and lingual recessions and inclination of the lower incisors during orthodontic treatment, vertical facial morphology, width of the alveolar bone process, height and width of their symphysis after orthodontic treatment and at long-term retention.

METHODS

On dental casts and good quality lateral cephalograms of 126 orthodontically treated patients, relevant measurements were performed and gingival recessions were assessed and recorded before, immediately after treatment and at long-term retention.

RESULTS

Taking into account the whole sample at three different occasions, on the buccal side, the lateral incisors have significantly less recessions than the central incisor. On the lingual side, tooth 32 presented with lower risk of recession compared to all other three incisors. No association was found between the width of the alveolar bone process at the apex (Wapex), at the level of the crest (Wcrest) and at mid of the root (Wmid), the width (D), the vertical skeletal pattern (AnsPns-Go'Me) and the onset of buccal or lingual recessions. Development of new recessions was clearly associated with males and with increasing age. The symphysis height (Me-Wcrest) was statistically related with the onset of lingual recessions on 32 and 42. The ratio between the symphysis height and the width at the crest level demonstrated a statistically significant association with the presence of buccal and lingual recessions. Excessive proclination (≥10°) of the lower incisors demonstrated an association with the onset of recessions in 25 per cent of the cases.

CONCLUSION

Based on the sample of this study, there is some evidence that increased symphysis height (Me-Wcrest), and ratio between the symphysis height and the width at the crest level as well as big change of lower incisor inclination during treatment are associated with the development of recessions.

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.

Correlation between gingival phenotype in the aesthetic zone and craniofacial profile-a CBCT-based study

OBJECTIVES

To investigate the correlation between gingival phenotype and craniofacial profile and to evaluate the morphology of periodontal supporting tissues in the maxillary and mandibular anterior zones.

MATERIALS AND METHODS

A total of 66 patients with 264 central incisors in good periodontal health were included in this cross-sectional study. CBCT images were used to assess gingiva and alveolar bone thickness of the maxillary and mandibular incisors at four vertical levels. Cephalometric analysis was used to assess the sagittal profile of the craniofacial structures. Gingival thickness was compared in patients with different craniofacial profiles based on ANB value. Linear regression coefficients adjusted by age and gender were used to evaluate the correlation between gingival thickness and the cephalometric parameters.

RESULTS

Individuals with a smaller ANB value (ANB< 2) presented with thinner supporting tissue and a keratinized gingiva width in the anterior zone. Labial gingival thickness on the mandibular incisors at the cementoenamel junction (G1) and at the alveolar bone crest (G2) was positively related to cephalometric measures, indicating a maxillae-mandibular sagittal relationship (ANB value, Wits appraisal, A-NPog value).

CONCLUSIONS

A moderate correlation was found between mandibular gingival thickness and the sagittal craniofacial profile. Patients with a concave craniofacial profile had a smaller keratinized gingiva width and gingival thickness in the aesthetic zone.

CLINICAL RELEVANCE

Knowledge of these features on supporting tissue and their correlations with craniofacial morphology will help clinicians to develop a reasonable treatment plan and make decisions to achieve the best aesthetic outcome.

Analysis of Alveolar Bone Morphology of the Maxillary Central and Lateral Incisors with Normal Occlusion

Background and objectives: This study investigated the morphology of the labial and palatal bony wall of the maxillary central and lateral incisors using cone-beam computed tomography (CBCT). The difference between males and females and the measurement between right and left sides were measured. Materials and Methods: Twenty participants, consisting of 11 females and 9 males having normal occlusion, were used for the analysis. The mean age was 21.9 ± 3.0 years. The thickness of the labial bony wall and palatal bony wall, perpendicular to the long axis of the root, were evaluated at 3 and 5 mm apical from the cemento-enamel junction (CEJ) and at the root apex. The available bony wall below the apex of the central and lateral incisors, and the angulation between the long axis of the tested tooth and outer surface of the labial bone were measured. Results: The mean labial bony wall thickness at the 3 and 5 mm apical from the CEJ were 1.1 ± 0.3 mm and 1.0 ± 0.4 mm for central incisors, respectively, as well as 1.2 ± 0.4 mm and 1.0 ± 0.4 mm for lateral incisors, respectively. The mean palatal bony wall thickness at 5 mm from the CEJ was above 2 mm in the central and lateral incisors. The percentage of labial bony wall thickness 2 mm or greater at the root apex in central incisors was higher than in lateral incisors (62.5% vs. 55.0%). The percentage of palatal bony wall thickness ≥2 mm at 3 mm apical from the CEJ in the central incisors was higher than in the lateral incisors (37.5% vs. 15.0%). The results on the left and right sides did not show statistically significant differences, except in the labial and palatal bony wall thickness at 3 mm from the CEJ in the lateral incisor. Generally, no significant differences were seen between males and females, but males had a significantly higher labial bony wall thickness at 3 and 5 mm from the CEJ in the central and lateral incisors when compared with females. Conclusions: This study showed that a majority of the cases of Korean participants had less than 2 mm of labial bony wall thickness at 3 and 5 mm apical from the CEJ at central and lateral incisors, and this should be kept in mind while performing dental practices, including tooth extraction or immediate implantation in anterior regions. Preoperative analysis using CBCT may be beneficial for establishing the treatment plan.

Prevalence of gingival biotype in adult patients of the dentistry services of two Peruvian hospitals April-June 2018

Introduction: The gingival biotype of a population is important epidemiological data for the best treatment planning, while preserving periodontal health. In Peru there is a shortage of similar data published. Objective: To determine the prevalence of gingival biotype in adult patients of the Dental Service of the Víctor Lazarte Echegaray and Hospital Regional Docente de Trujillo, April - June 2018. Ma-terials and Methods: This cross-sectional, descriptive and observational study included 200 patients from the Dentistry Service of the Víctor Lazarte Echegaray and Hospital Regional Docente de Trujillo. Using the accidental non-probabilistic selection method, the gingival biotype was evaluated through the transparency of periodontal probe technique. To determine the reliability of the method the Kappa statistic was used, finding an inter-evaluator reliability of 0.750 and intra-evaluator of 0.762. Descriptive statistics were used for the results, presenting absolute and percentage frequencies. Results: The prevalence of the thick gingival biotype was 57.5%. Males and females presented predominantly a thick biotype, 63.1% and 54.8% respectively. The groups of 18 to 29 and 30 to 39 years old presented 62.1% and 64.5% a thick biotype, respectively. On the other hand, the majority of people 40 to 50 years old presented a thin gingival biotype (52.8%). Conclusions: The thick gingival biotype was predominant in both sexes and in both hospitals. Also, gingival biotype varies with age, with the thick biotype more prevalent in younger age groups.

A novel soft tissue thickness measuring method using cone beam computed tomography

OBJECTIVE

The aim of this study was to introduce a novel soft tissue thickness measurement method using cone beam computed tomography (CBCT) and to compare the new method with ultrasonic device applications and transgingival probing measurements.

METHODS

Twenty-five participants (12 female, 13 male, age range, 25-51 years) were included the study. Soft tissue thickness in lateral incisor, canine, premolar, and molar regions were measured using transgingival probing (group T), ultrasonic device (group U), and CBCT scan measurements (group C). Differences and correlations between groups and agreement between measurement methods were evaluated.

RESULTS

Soft tissue thickness was significantly lower in group U in premolar region, but was significantly higher in molar region compared with group C and group T (P < .05). There were significant positive correlations in lateral incisor and canine region, between group U and group C, in premolar region between group T and group C, and in molar region between group U and group C, and between group C and group T (P < .05). The highest agreement between measurement methods was evident between group T and group C.

CONCLUSION

Soft tissue thickness values in maxilla may differ depending on the measurement method and location of the measurement. Ultrasonic device, transgingival probing, and CBCT measures may not necessarily correlate in all locations. The high agreement between CBCT measurements and transgingival probing may suggest the newly introduced method as a promising technique for soft tissue thickness evaluation.

CLINICAL SIGNIFICANCE

This study evaluated the relation between different soft tissue thickness measurement methods and demonstrated a novel method which can be used in any part of the mouth. The outcome also suggested that the measurement method and the location might affect the soft tissue thickness value obtained, and therefore might be important in clinical decision making.

Clinical Efficacy and Patient Perceptions of Pyogenic Granuloma Excision Using Diode Laser Versus Conventional Surgical Techniques

The use of laser in oral surgery and periodontology is a matter of debate, mainly because of the lack of consensual therapeutic protocols. The aim of this study was to evaluate the surgical advantages of diode laser versus traditional surgery with a cold blade for the surgical excision of pyogenic granuloma (PG). Twenty-one patients (10 males, 11 females, aged 19-66 years; mean age: 46.5 years), requiring PG excision, were enrolled in the study. Through a randomized clinical trial design, all patients were randomly subjected to PG surgical excision with either diode laser or cold blade. Parameters analyzed were the speed of incision, time of intervention, intraoperative bleeding, number of stitches, and patient compliance. Histologic examination was performed before and after surgical excision of the lesions. Patients compiled a subjective evaluation questionnaire. Both treatments were successful in surgical excision of PG. However, the mean speed of incision was significantly reduced in diode laser group (0.61 ± 0.29 mm/s) compared with cold blade group (1.47 ± 1.23 mm/s) (P < 0.05). The mean lengths of time for the whole surgical intervention were significantly lower in diode laser group (221.15 ± 220.89 s) compared with cold blade group (316.10 ± 248.69 s) (P < 0.05). Moreover, diode laser induced a reduced intrasurgical bleeding, and a better gingival healing compared with cold blade surgical treatment. This study demonstrated that the use of diode laser showed additional advantages compared with cold blade in terms of less postoperative discomfort and pain for surgical removal of PG.

Assessment of Periodontal Biotype in a Young Chinese Population using Different Measurement Methods

Periodontal biotype is used to describe the morphological characteristics of periodontal tissues and is closely related to periodontal health and prognosis of many dental treatments. This study was undertaken to explore the periodontal biotype distribution in a young Chinese population and to evaluate the accuracy of different methods for gingival thickness (GT) measurement. A total of 372 teeth from 31 periodontally healthy subjects were included. GT was measured simultaneously by probe transparency, transgingival probing and cone-beam computed tomography (CBCT). Some other anatomic parameters, including crown width/crown length ratio, attached gingival width, labial bone thickness and papilla volume were recorded for periodontal biotype classification. As found by probe transparency, the gingivae of 222 teeth (59.68%) were thick, while those of 150 teeth (40.32%) were thin. The mean GT of included subjects was 1.03 ± 0.31 mm as measured by transgingival probing and 1.03 ± 0.24 mm as measured by CBCT. Four groups were identified by cluster analysis. Thick-flap biotype, average-scalloped biotype, average-flap biotype and thin-scalloped biotype comprised 137 teeth (36.83%), 96 teeth (25.81%), 39 teeth (10.48%) and 100 teeth (26.88%), respectively. These results demonstrate that the most common periodontal biotype in this young Chinese population was the thick-flap type with low aesthetic risk.

Measurement properties of gingival biotype evaluation methods

BACKGROUND

There are numerous methods to measure the dimensions of the gingival tissue, but few have compared the effectiveness of one method over another.

OBJECTIVE

This study aimed to describe a new method and to estimate the validity of gingival biotype assessment with the aid of computed tomography scanning (CTS).

MATERIALS AND METHODS

In each patient different methods of evaluation of the gingival thickness were used: transparency of periodontal probe, transgingival, photography, and a new method of CTS). Intrarater and interrater reliability considering the categorical classification of the gingival biotype were estimated with Cohen's kappa coefficient, intraclass correlation coefficient (ICC), and ANOVA (P < .05). The criterion validity of the CTS was determined using the transgingival method as the reference standard. Sensitivity and specificity values were computed along with theirs 95% CI.

RESULTS

Twelve patients were subjected to assessment of their gingival thickness. The highest agreement was found between transgingival and CTS (86.1%). The comparison between the categorical classifications of CTS and the transgingival method (reference standard) showed high specificity (94.92%) and low sensitivity (53.85%) for definition of a thin biotype.

CONCLUSION

The new method of CTS assessment to classify gingival tissue thickness can be considered reliable and clinically useful to diagnose thick biotype.

[How to analyze periodontal morphotypes in order to reduce the risk of periodontal recession]

INTRODUCTION

The periodontal morphotype is a leading feature to be born in mind during surgical, implant, prosthetic, restorative as well as orthodontic treatment. A fragile morphotype will rapidly trigger severe and worrying clinical repercussions for the patient.

MATERIALS AND METHODS

In order to minimize the risks involved, sound knowledge of the different morphotypes and of the techniques for clinically evaluating them is a major requirement. These factors need to be regularly reassessed since morphotypes can vary throughout the course of treatment.

RESULTS

Detecting and controlling mucogingival risk factors will enable an appropriate clinical approach designed to avoid the onset of secondary recessions or other gingival pathologies.

New method of assessing the relationship between buccal bone thickness and gingival thickness

Purpose

The aim of this study was to determine the relationship between buccal bone thickness and gingival thickness by means of a noninvasive and relatively accurate digital registration method.

Methods

In 20 periodontally healthy subjects, cone-beam computed tomographic images and intraoral scanned files were obtained. Measurements of buccal bone thickness and gingival thickness at the central incisors, lateral incisors, and canines were performed at points 0–5 mm from the alveolar crest on the superimposed images. The Friedman test was used to compare buccal bone and gingival thickness for each depth between the 3 tooth types. Spearman's correlation coefficient was calculated to assess the correlation between buccal bone thickness and gingival thickness.

Results

Of the central incisors, 77% of all sites had a buccal thickness of 0.5–1.0 mm, and 23% had a thickness of 1.0–1.5 mm. Of the lateral incisors, 71% of sites demonstrated a buccal bone thickness <1.0 mm, as did 63% of the canine sites. For gingival thickness, the proportion of sites <1.0 mm was 88%, 82%, and 91% for the central incisors, lateral incisors, and canines, respectively. Significant differences were observed in gingival thickness at the alveolar crest level (G0) between the central incisors and canines (P=0.032) and between the central incisors and lateral incisors (P=0.013). At 1 mm inferior to the alveolar crest, a difference was found between the central incisors and canines (P=0.025). The lateral incisors and canines showed a significant difference for buccal bone thickness 5 mm under the alveolar crest (P=0.025).

Conclusions

The gingiva and buccal bone of the anterior maxillary teeth were found to be relatively thin (<1 mm) overall. A tendency was found for gingival thickness to increase and bone thickness to decrease toward the root apex. Differences were found between teeth at some positions, although the correlation between buccal bone thickness and soft tissue thickness was generally not significant.