Variance components of gingival thickness

Impact of periodontal phenotype on the outcome of subgingival instrumentation in Stage II and III, Grade A and B periodontitis

Background

The influence of periodontal phenotype (PP) has been documented in the outcomes of various surgical periodontal interventions such as crown lengthening, mucogingival surgery, implant restoration, and open flap debridement. Previous studies with smaller sample sizes have assessed the role of PP on the outcome of nonsurgical periodontal therapy with inconsistent results.

Aim

The aim of the current interventional study is to estimate the influence of PP on the outcome of subgingival instrumentation in Stage II and III, Grade A and B periodontitis.

Materials and Methods

Fifty-two patients (n = 27 thick PP and n = 25 thin PP) underwent subgingival instrumentation using ultrasonic scalers and curettes under local anesthesia in a single sitting, and periodontal parameters were recorded at baseline, 2, 4, and 6 months. The McNemar and Chi-square tests were applied for categorical data, whereas the Wilcoxon signed-rank test and Mann-Whitney U-test were applied for continuous data in intra- and intergroup comparisons, respectively.

Results

Significantly better improvements in deeper pockets (>5 mm) with thick PP were observed. Loss of attachment was found in thin, bleeding on probing (BOP)-negative sites with an initial probing depth of ≤3 mm. However, BOP-positive sites belonging to both groups exhibited higher improvements in terms of clinical parameters.

Conclusion

Probing depth, PP, and periodontal inflammation recorded in terms of BOP influence the gain in clinical attachment following subgingival instrumentation.

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.

An evaluation of gingival phenotype and thickness as determined by indirect and direct methods

OBJECTIVES

To evaluate gingival phenotype (GP) and thickness (GT) using visual, probing, and ultrasound (US) methods and to assess the accuracy and consistency of clinicians to visually identify GP.

MATERIALS AND METHODS

The GP and GT of maxillary and mandibular anterior teeth in 29 orthodontic patients (mean age 25 ± 7.5 years) were assessed using probing and US by a single examiner. General dentist and dental specialist assessors (n = 104) were shown intraoral photographs of the patients, including six repeated images, and asked to identify the GP via a questionnaire.

RESULTS

An increasing trend in GT values of thin, medium, and thick biotype probe categories was found, though this was not statistically significant (P = .188). Comparison of probing method to determinations of GT made by US yielded slight agreement (κ = 0.12). Using the visual method, assessors' identification of the second GP determination ranged from poor to moderate agreement (κ = 0.29 to κ = 0.53).

CONCLUSIONS

The probe method is sufficient in differentiating between different categories of GP. However, further research is required to assess the sensitivity of the probe method in recognizing phenotypes in the most marginal of cases. Assessors using the visual method lack the ability to identify GP accurately and consistently among themselves.

Overview of Ultrasound in Dentistry for Advancing Research Methodology and Patient Care Quality with Emphasis on Periodontal/Peri-implant Applications

BACKGROUND

Ultrasound is a non-invasive, cross-sectional imaging technique emerging in dentistry. It is an adjunct tool for diagnosing pathologies in the oral cavity that overcomes some limitations of current methodologies, including direct clinical examination, 2D radiographs, and cone beam computerized tomography. Increasing demand for soft tissue imaging has led to continuous improvements on transducer miniaturization and spatial resolution. The aims of this study are (1) to create a comprehensive overview of the current literature of ultrasonic imaging relating to dentistry, and (2) to provide a view onto investigations with immediate, intermediate, and long-term impact in periodontology and implantology.

METHODS

A rapid literature review was performed using two broad searches conducted in the PubMed database, yielding 576 and 757 citations, respectively. A rating was established within a citation software (EndNote) using a 5-star classification. The broad search with 757 citations allowed for high sensitivity whereas the subsequent rating added specificity.

RESULTS

A critical review of the clinical applications of ultrasound in dentistry was provided with a focus on applications in periodontology and implantology. The role of ultrasound as a developing dental diagnostic tool was reviewed. Specific uses such as soft and hard tissue imaging, longitudinal monitoring, as well as anatomic and physiological evaluation were discussed.

CONCLUSIONS

Future efforts should be directed towards the transition of ultrasonography from a research tool to a clinical tool. Moreover, a dedicated effort is needed to introduce ultrasonic imaging to dental education and the dental community to ultimately improve the quality of patient care.

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.

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.

Clinical Outcomes of the Double Lateral Sliding Bridge Flap Technique with Simultaneous Connective Tissue Graft in Sextant V Recessions: Three-Year Follow-Up Study

The presence of isolated or multiple gingival recessions in the mandibular anterior region is a challenge for the clinician, as they may be associated with a shallow vestibule, high frenum insertion and/or little or no attached gingiva. Only limited evidence is available on the use of the double lateral sliding bridge flap technique with connective tissue graft (CTG) technique for treating gingival recessions in the mandibular anterior region. The aim of this study was to describe and evaluate the clinical and esthetic outcomes of the double lateral sliding bridge flap technique with CTG on isolated and multiple gingival recessions at the level of the mandibular incisors. Nine patients required treatment of gingival recessions in the mandibular incisors at the University of Salamanca (Spain) (seven females, two males; mean age: 27.9 ± 6.9) with a total of 14 isolated (42.9%) and multiple (57.1%) Miller class II and III gingival recessions. After a mean follow-up of 36 months, the mean percentage of root coverage was 80.5% for all treated recessions. Statistically significant differences (p < 0.05), were observed for reduction in recession depth, increased width of keratinized tissue and increased gingival thickness, this being dependent on the Miller class. The esthetic outcome was acceptable, with a final mean esthetic score of 7.4 out of 10. The double lateral sliding bridge flap surgical technique with CTG is an effective procedure for the coverage of isolated and multiple gingival recessions in the anterior mandibular region, as it offers satisfactory esthetic results.

Radiographic and Esthetic Evaluation Following Immediate Implant Placement with or without Socket Shield and Delayed Implant Placement Following Socket Preservation in the Maxillary Esthetic Region - A Randomized Controlled Clinical Trial

OBJECTIVE

The purpose of this study was assessment of the changes in soft and hard tissues in the esthetic zone of maxilla following immediate implant placement (IIP) with and without the socket shield technique (SST) and placement of implants 4 months following socket preservation (DIP) in terms of alterations in crestal bone thickness (CBT) and soft tissue changes evaluated by means of pink esthetic scores (PES) following placement of implants in the esthetic zone of maxilla.

MATERIALS AND METHODS

In the maxillary esthetic region, 75 dental implants were placed totally, with 25 implants each in the SST, IIP, and DIP groups. All participants were subjected to undergo CBCT for assessing the variations in thickness of crestal aspect of facial/buccal/labial alveolar bone (CBT). PES and PROMS (patient-related outcome measures) were assessed using VAS for pain threshold and esthetic satisfaction following implant placement and after 6th post-operative month.

RESULTS

The mean reduction in CBT showed a statistically significant difference between and within the groups, in comparison to IIP and DIP groups, which demonstrated an average reduction in CBT 0.4 ± 0.1 and 0.2 ± 0.1 at 6 months following implant placement, respectively. The SST group showed a significantly lesser reduction in CBT of 0.05 ± 0.02. However, the mean difference in PES within and among the groups showed no significant difference statistically at P < 0.05. On comparison of individual scores of PES between the groups, the results showed significant difference statistically at P < 0.001.

CONCLUSION

The SST group demonstrated minimal reduction in CBT and a superior PES at the end of 6 months compared with the IIP and DIP groups.

Width and thickness of the gingiva in periodontally healthy individuals in a central Indian population: a cross-sectional study

OBJECTIVES

The present study was performed to determine the gingival dimensions (width and thickness) among young individuals in a central Indian population.

MATERIALS AND METHODS

Periodontal probing depth, width of the keratinized and attached gingiva, and gingival thickness were recorded on maxillary and mandibular teeth from central incisor to first molar unilaterally in 75 systemically healthy individuals (32 males and 43 females; 19-30 years of age). Comparisons were made gender-wise, arch-wise, tooth-wise, and site-wise using either the Student's t test or the ANOVA.

RESULTS

Keratinized and attached gingiva were wider in the maxilla than in the mandible both at proximal and at mid-buccal aspects (p < 0.001). At the tooth level also, gingiva was wider at the maxillary teeth than the corresponding mandibular teeth and at proximal aspects than at the mid-buccal aspect (p < 0.001). Regarding the thickness, gingiva was thicker among males, in the mandible, and at inter-proximal sites (p < 0.001). In either arch, maximum thickness was observed at the incisor region and least at the canine region.

CONCLUSIONS

Dimensions of the gingival tissues vary between different populations and between different areas of the dentition within the same subject. These variations need to be better understood because these aspects may have an important bearing on periodontal treatment planning as width and thickness of gingiva are important in terms of maintenance of periodontal health.

CLINICAL RELEVANCE

The dimensions of the clinically healthy gingiva are important in clinical practice as they can influence the progression of periodontal disease as well as impact the outcome of periodontal and restorative and orthodontic therapy.

Gingival phenotype distribution in young Caucasian women and men - An investigative study

OBJECTIVES

To evaluate the relationship between gingival phenotype and tooth location based on selected index teeth ("Ramfjord") and assess possible differences between women and men.

MATERIAL AND METHODS

Thirty-six women and 20 men voluntarily participated in this investigation with an average age of 23 years (min: 19; max: 37). Gingival phenotypes (GP) were assessed by transparency of a periodontal probe through the buccal gingival margin.

RESULTS

A comparable and similar GP on all index teeth was only found in seven out of the 56 subjects, that is, thin or thick only: Five participants (three male/two female) showed a uniform and constantly thick and two females a constantly thin GP. While the majority of molars (94.6%; p = 0.006) showed a thick GP, premolars (61.6%; p = 0.09) as well as incisors (70.5%; p = 0.046) were predominantly categorized as thin. In addition, significantly thicker GP was in general observed for maxillary teeth (p = 0.001) but without differences between genders (p = 0.722).

CONCLUSION

No constant GP can be expected within one dentition. The use of the "Ramfjord teeth" may serve as a quick overview and reliable method to screen GP distribution.

[Three-dimensional morphology analysis of the supraosseous gingival profile of periodontally healthy maxillary anterior teeth]

OBJECTIVE

To measure the three-dimensional morphology of the labial supraosseous gingiva (SOG) and the thickness of related labial bone in maxillary anterior teeth of periodontally healthy Han nationality youth using soft tissue indirect imaging cone-beam computed tomography (CBCT).

METHODS

Twenty-five periodontally healthy subjects (11 males and 14 females) with 150 maxillary anterior teeth were involved in this study. A special impression with radiopaque material including the maxillary teeth was made, then a CBCT scan with the elastomeric matrix in position was taken for each subject. The imaging data were generated and transferred to a volumetric imaging software in which three-dimensional reconstruction was conducted and the image analyses were carried out. Measurements were made at the site of labial center of the maxillary anterior teeth. The height of the SOG, the distance between cemento-enamel junction (CEJ) and bone crest, the gingival thickness at the CEJ, and the thickness of bone 2 mm below the labial bone crest were measured and the correlation analysis between the parameters was made. All the data analyses were performed using SPSS 22.0. The data were analyzed with ANVOA and Pearson correlation tests with the significance level at α=0.05.

RESULTS

The mean SOG values were (3.49±0.70) mm, (3.48±0.81) mm, and (3.54±0.67) mm for central incisors, lateral incisors and canines, respectively. There were no statistically significant differences among the different sites (P > 0.05). The mean gingival thickness values were (1.45±0.23) mm, (1.13±0.24) mm, (1.14±0.22) mm for central incisors, lateral incisors and canines, respectively. The gingival thickness of the central incisors was the largest among the maxillary anterior teeth with statistically significant difference (P < 0.05). No correlation was found between the SOG and gingival thickness among the maxillary anterior teeth (P > 0.05).

CONCLUSION

The gingival thickness of central incisors was the largest and the supraosseous gingival height had no correlation with gingival thickness among the periodontally healthy maxillary anterior teeth.

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.

Ultrasonography for noninvasive and real-time evaluation of peri-implant soft and hard tissue: a case series

BACKGROUND

The diagnosis of soft and hard tissue at dental implants will be challenging in the future, as high prevalence of mucositis and peri-implantitis were described in the population. Ultrasonography is a promising non-invasive, inexpensive, painless, and radiation-free method for imaging hard and soft tissue at implants, especially an ultrasound device with a 25-MHz probe demonstrating a high correlation between ultrasound, clinical, and radiological measurements.

CASE PRESENTATION

The following case series demonstrates the use of ultrasonography with high spatial resolution probe in patients with dental implants affected by soft tissue recession and/or crestal bone loss.

CONCLUSION

These ultrasound images can provide valuable additional information for the assessment of peri-implant soft and hard tissue.

The effect of different micro-osteoperforation depths on the rate of orthodontic tooth movement: A single-center, single-blind, randomized clinical trial

OBJECTIVE

This study aimed to identify the clinical effectiveness of two different penetration depths of micro-osteoperforations (MOPs) on the rate of orthodontic tooth movement.

METHODS

Twenty-four patients requiring the removal of the upper first premolar teeth were selected and randomly divided into two groups. The control group participants did not undergo MOPs. Participants in the experimental group underwent three MOPs each at 4-mm (MOP-4) and 7-mm (MOP-7) depths, which were randomly and equally performed to either the left or right side distal to the canine. The retraction amount was measured on three-dimensional digital models on the 28th day of retraction. MOP-related pain was measured using a visual analog scale (VAS). Between-group statistical differences in the VAS scores were determined using an independent t-test and those in canine retraction were determined using analysis of variance and posthoc Tukey test.

RESULTS

No significant difference was found between the MOP- 4 (1.22 ± 0.29 mm/month) and MOP-7 (1.29 ± 0.31 mm/month) groups in terms of the canine retraction rate. Moreover, both the groups demonstrated a significantly higher canine movement than the control group (0.88 ± 0.19 mm/ month). MOPs did not significantly affect the mesialization of the posterior teeth (p > 0.05). Moreover, the pain scores in the MOP-4 and MOP-7 groups were similar and showed no statistically significant difference.

CONCLUSIONS

Three MOPs with a depth of 4 mm can be performed as an effective method to increase the rate of tooth movement. However, three MOPs with depths of 4-7 mm does not additionally enhance tooth movement.

Periodontal and Implant Radiology

Dental radiography can be used to detect alveolar bone levels around periodontal and peri-implant structures. Periodontal radiographic images can assess alveolar bone height, periodontal ligament, furcation involvement, and evidence of bone destruction. Peri-implant radiographic images can assess the alveolar bone height in relation to the implant structure. As an adjunct to patient care, radiography can aid in the diagnosis of non-health.

Gingival phenotype and its relationship with different clinical parameters: a study in a Dominican adult sample

OBJECTIVES

The purpose of this study was to estimate the prevalence of thin and thick gingival phenotype (GPh) in a sample of Dominican subjects and correlate it with clinical parameters.

MATERIALS AND METHODS

One-hundred seven periodontal healthy volunteers in the range of 18-73 years were enrolled in the study. GPh was defined by the transparency of a periodontal probe through the buccal gingival margin on the upper right or left central incisor. Clinical periodontal parameters such as keratinized gingiva width (WKG), attached gingiva width (WAG), probing depth (PD), plaque index (PI), and gingival index (GI) were recorded by a calibrated examiner. Frequency distribution of qualitative variables was calculated. For quantitative variables, Mann-Whitney and Kruskal-Wallis tests were used for comparison of groups.

RESULTS

There was no association between GPh and sex. There were no significant differences between thin and thick GPh regarding age, PD, GI, and interproximal index. The association between tooth morphology and GPh was significant (p = 0.018). Median amount of keratinized gingiva was significantly larger (p = 0.01) in subjects with thin gingival phenotype (median = 6.00 mm) when compared with subjects with thick gingival phenotype (median = 5 mm).

CONCLUSIONS

Subjects with thin GPh presented larger WKG. Furthermore, there was an association between tooth morphology and GPh.

CLINICAL RELEVANCE

This is the first study to report the distribution of gingival phenotype and its relationship with different periodontal parameters of a Caribbean population. Our findings can contribute to the clinicians when planning or performing dental procedures.

Clinical evaluation of impact of periodontal phenotype on the outcome of open flap debridement in patients with chronic periodontitis: A comparative interventional study

BACKGROUND

Several studies have implicated the role of periodontal phenotype (PP) in the outcome of various periodontal interventions. However investigations have not been performed to estimate such impact on the outcome of open flap debridement (OFD) for the management of chronic periodontitis.

METHODS

A total of 73 individuals with chronic periodontitis underwent scaling and root planing (SRP). Eight weeks following SRP, modified Widman flap (MWF) surgery was performed in 40 patients (20 of either PP) presenting with probing depth (PD) ≥4 mm and gingival index (GI) ≥1 at ≥4 sites distributed over ≥2 anterior teeth with radiographic evidence of horizontal bone loss. PD, clinical attachment level (CAL), gingival recession, plaque index, GI, and bleeding on probing (BOP) were recorded at baseline, 3 and 6 months. PP was assessed using transparency of periodontal probe through the gingival margin at midfacial level.

RESULTS

A total of 34 patients were re-evaluated after intervention. All periodontal parameters improved in both groups after periodontal surgery. PD & PP were found to have positive correlation with CAL gain in ≥7 mm probing sites. Attachment gain of >2 mm was observed in more percentage of sites in thick PP than in thin PP.

CONCLUSION

PP can be an important factor influencing CAL gain in OFD.

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.

Correlation between clinical parameters of crown and gingival morphology of anterior teeth and periodontal biotypes

Background

In this study, we conducted a quantitative analysis of the clinical parameters of crown and gingival morphology (CGM) of the maxillary anterior teeth (MAT). We also analyzed the correlation of these parameters with periodontal biotype (PB), with a view to providing objective standards for PB diagnosis.

Methods

The three-dimensional (3D) maxillary digital models of 56 individuals were obtained using an intra-oral scanner. The following parameters were measured with the SpaceClaim software: gingival angle (GA), papilla width (PW), papilla height (PH), crown length (CL), crown width (CW), crown width/crown length ratio (CW/CL), bucco-lingual width of the crown (BLW), contact surface width (CSW), and contact surface height/crown length ratio (CS/CL). The PB were determined based on the transparency of the periodontal probe through the gingival sulcus. Independent factors influencing PB were analyzed by logistic regression, and the optimal cutoff values for the independent influencing factors were analyzed using receiver operating characteristic curves (ROC curves).

Results

There was no significant difference in the parameters of CGM of the MAT at the left and right sides. The thick biotype accounted for 69.6%, and the parameters of GA, PW, PH, CW, CW/CL and CS/CL were significantly correlated with PB (P ≤ 0.2). GA (odds ratio (OR) = 1.206) and PW (OR = 5.048) were identified as independent predictive factors of PB, with areas under the ROC curve (AUC) of 0.807 and 0.881, respectively, and optimal cutoff values of 95.95° and 10.01 mm, respectively.

Conclusion

The CGMs of the MAT at the left and right side are symmetrical. The thin biotype accounts for a small proportion, and GA and PW are independent influencing factors of PB. GA of 95.95° and PW of 10.01 mm are the optimal cutoff values for categorization of individuals as thick biotype. This indicates that when the GA and PW of the right maxillary central incisor are G ≥ 95.95° and ≥ 10.01 mm, respectively, there is a higher probability that these individuals will be categorized as thick biotype.

Ultrasonography for chairside evaluation of periodontal structures: A pilot study

BACKGROUND

The crestal bone level and soft tissue dimension are essential for periodontal diagnosis and phenotype determination; yet, existing measurement methods have limitations. The aim of this clinical study was to evaluate the correlation and accuracy of ultrasound in measuring periodontal dimensions, compared to direct clinical and cone-beam computed tomography (CBCT) methods.

METHODS

A 24-MHz ultrasound probe prototype, specifically designed for intraoral use, was employed. Periodontal soft tissue dimensions and crestal bone levels were measured at 40 teeth and 20 single missing tooth gaps from 20 patients scheduled to receive a dental implant surgery. The ultrasound images were interpreted by two calibrated examiners. Inter-rater agreement was calculated by using inter-rater correlation coefficient (ICC). Ultrasound readings were compared with direct clinical and CBCT readings by using ICC and Bland-Altman analysis.

RESULTS

The following six parameters were measured: 1) interdental papilla height (tooth), 2) mid-facial soft tissue height (tooth), 3) mucosal thickness (tooth), 4) soft tissue height (edentulous ridge), 5) mucosal thickness (edentulous ridge), and 6) crestal bone level (tooth). Intra-examiner calibrations were exercised to achieve an agreement of at least 0.8. ICC between the two readers ranged from 0.482 to 0.881. ICC between ultrasound and direct readings ranged from 0.667 to 0.957. The mean difference in mucosal thickness (tooth) between the ultrasound and direct readings was -0.015 mm (95% CI: -0.655 to 0.624 mm) without statistical significance. ICC between ultrasound and CBCT ranged from 0.654 to 0.849 among the measured parameters. The mean differences between ultrasound and CBCT range from -0.213 to 0.455 mm, without statistical significance.

CONCLUSION

Ultrasonic imaging can be valuable for accurate and real-time periodontal diagnosis without concerns about ionizing radiation.

Association between Gingival Biotype and Facial Typology through Cephalometric Evaluation and Three-Dimensional Facial Scanning

In dentistry, the assessment of periodontal biotype is considered one of the most important parameters with which to plan treatment, and craniofacial morphology might affect it. The aim of this study was to investigate the association between facial typology and gingival biotype in patients by means of two-dimensional and three-dimensional evaluations of facial typology. This study included 121 participants searching for orthodontic treatment (43 M, 78 F; 20.4 ± 10.4). Gingival biotype was evaluated based on the transparency of the periodontal probe through the gingival margin of the mid-buccal sulcus for both upper (UGB) and lower (LGB) anterior teeth. SellionNasion^GonionGnation (SN^GoGn) and CondylionGonionMenton (CoGoMe^) angles were measured on two-dimensional cephalograms. Three-dimensional face scans were acquired by means of a three-dimensional facial scanner (3dMD system) and successively analyzed to assess the facial typology using the ratio between lower facial height (SNMe) and total facial height (NMe). A chi-squared test and regression analysis were used to evaluate the associations between gingival biotype and facial morphology (p < 0.05). The chi-squared test showed that there was no statistically significant association between facial typology and gingival biotype (UGB p = 0.83; LGB p = 0.75). The logistic regression showed an association between SNMe/NMe and the UGB (p = 0.036), and SNMe/NMe and LGB (p = 0.049). The decreased ratio of SNMe/NMe might be a protective factor for a thin gingival biotype.

A noninvasive imaging and measurement using optical coherence tomography angiography for the assessment of gingiva: An in vivo study

Gingiva is the soft tissue that surrounds and protects the teeth. Healthy gingiva provides an effective barrier to periodontal insults to deeper tissue, thus is an important indicator to a patient's periodontal health. Current methods in assessing gingival tissue health, including visual observation and physical examination with probing on the gingiva, are qualitative and subjective. They may become cumbersome when more complex cases are involved, such as variations in gingival biotypes where feature and thickness of the gingiva are considered. A noninvasive imaging technique providing depth-resolved structural and vascular information is necessary for an improved assessment of gingival tissue and more accurate diagnosis of periodontal status. We propose a three-dimensional (3D) imaging technique, optical coherence tomography (OCT), to perform in situ imaging on human gingiva. Ten volunteers (five male, five female, age 25-35) were recruited; and the labial gingival tissues of upper incisors were scanned using the combined use of state-of-the-art swept-source OCT and OCT angiography (OCTA). Information was collected describing the 3D tissue microstructure and capillary vasculature of the gingiva within a penetration depth of up to 2 mm. Results indicate significant structural and vascular differences between the two extreme gingival biotypes (ie, thick and thin gingiva), and demonstrate special features of vascular arrangement and characteristics in gingival inflammation. Within the limit of this study, the OCT/OCTA technique is feasible in quantifying different attributes of gingival biotypes and the severity of gingival inflammation.

Determinação do biótipo periodontal através da análise de fotografias intra-orais

Resumo Objetivo Caracterizar os Biótipos Periodontais (BP) por meio de fotografias, além de verificar a concordância com o método clínico de determinação, bem como com diferentes profissionais em Odontologia. Material e método A avaliação clínica intra-bucal de 34 pacientes (n=34) e verificação de fotografias padronizadas foram realizadas para caracterização dicotômica do BP em fino e espesso. A avaliação subjetiva, por meio da fotografia, foi comparada ao método clínico da transparência à sondagem. A determinação do BP por meio de fotografias foi realizada através da aplicação de um questionário contendo três categorias (fino, espesso e intermediário), direcionadas a 90 cirurgiões-dentistas divididos igualmente em três grupos: clínicos gerais, periodontistas e protesistas. A concordância em ambas as comparações foi avaliada por meio do Teste Kappa, além dos testes de sensibilidade e especificidade. Resultado Na comparação entre o método clínico e o fotográfico, não houve concordância (K = 0,264, p = 0,113). Na comparação entre os grupos dos profissionais, foi encontrada uma baixa concordância (kappa = 0,160; p<0,05) entre os periodontistas e protesisas, bem como entre protesistas e clínicos gerais (kappa = 0,110; p = 0,142). Houve maior concordância, ainda que fraca, entre periodontistas e clínicos gerais (kappa = 0,291; p = 0,00). O questionário obteve um valor de sensibilidade e especificidade maior para o diagnóstico do BP espesso. Conclusão A avaliação clínica do paciente por meio dos parâmetros clínicos ainda é necessária para caracterizar o BP, visto que a determinação usando-se análise visual por meio do fotografia, independentemente da especialidade, não foi efetiva, embora o BP espesso tenha sido o mais facilmente identificado.

Ultrasonography for noninvasive and real-time evaluation of peri-implant tissue dimensions

AIM

Existing methods for evaluating marginal bone loss and tissue biotype around dental implants present with many limitations. The aim of this study was to examine the accuracy of high-resolution, 3-dimensional ultrasound to measure peri-implant tissue dimensions.

MATERIAL AND METHODS

A 25-MHz ultrasound probe prototype was used to scan peri-implant tissues of 17 implants from seven fresh human cadavers. Four ultrasonic measurements were made as follows: the marginal bone level/thickness, and mucosal level/thickness. The readings were statistically compared to cone beam computed tomography (CBCT) and/or open bone measurements.

RESULTS

The correlations (r) between the ultrasound and direct/CBCT readings of the four parameters ranged from 0.85 to 0.98 (p < 0.0001). The mean absolute difference in the four parameters between ultrasound-direct and ultrasound-CBCT ranged from 0.033 to 0.24 mm.

CONCLUSION

Encouraging evidence is shown that ultrasound can accurately measure peri-implant tissue dimensions. Following clinical trial validations, ultrasound offers potential as a valuable tool to evaluate long-term peri-implant tissue stability without concerns of ionizing radiation and image artefacts around implants.

Integration of ultrasound imaging into pre-clinical dental education

INTRODUCTION

Patients have complex healthcare needs and typically require more than one healthcare discipline to address issues regarding their health. Interprofessional teams of healthcare professionals may be able to address these complex needs and improve patient outcomes by combining resources. To evaluate the feasibility of integrating ultrasound into a dental school curriculum to teach anatomy as part of an interprofessional education experience, the current study surveyed first-year dental students to determine their perceptions of the integration of ultrasound techniques into the curriculum.

MATERIALS AND METHODS

Ultrasound laboratory exercises were developed for first-year dental students as part of their anatomy course. The exercises were focused on head, neck and abdominal anatomy. To assess student perception of the integration of ultrasound into the dental curriculum, a survey was created specifically for the current study.

RESULTS

Between 2013 and 2015, two classes of first-year dental students participated in the ultrasound laboratory exercise and completed the survey (n = 83). Student survey responses suggested ultrasound was a valuable teaching tool because it allowed them to visualise anatomical structures using live imaging. They also agreed that the ultrasound laboratory exercises were an efficient learning tool, but the majority did not believe that they would use ultrasound regularly in their future practice.

CONCLUSIONS

Results of the current study suggested first-year dental students were satisfied with the integration of ultrasound techniques into the dental curriculum. Survey results indicated that the students enjoyed the ultrasound laboratory exercise and felt ultrasound was an effective learning tool.

Observation and determination of periodontal tissue profile using optical coherence tomography

BACKGROUND AND OBJECTIVE

Diagnosis is a crucial step in periodontal treatment. The aim of this study was to evaluate the effectiveness of optical coherence tomography (OCT) for observation and determination of periodontal tissue profiles in vivo.

MATERIAL AND METHODS

In experiment 1, refractive indices of purified water, porcine gingiva and human gingiva at 1330 nm were determined for the analysis of OCT images of periodontal tissues. In experiment 2, OCT examination was performed in the midlabial apico-coronal plane of mandibular anteriors in 30 Asian volunteers with healthy gingiva. Sulcus depth was measured on intra-oral photographs taken during probing. In the OCT images, the gingival, epithelial and connective tissue thickness, and the position of alveolar bone crest were determined and finally, the biologic width was measured.

RESULTS

Refractive indices of purified water, porcine gingiva and human gingiva were 1.335, 1.393 and 1.397, respectively. Cross-sectional images of gingival epithelium, connective tissue and alveolar bone were depicted in real-time. The sulcular and junctional epithelium could be visualized occasionally. Laser penetration and reflection were limited to a certain depth with an approximate maximal imaging depth capability of 1.5 mm and OCT images of the periodontal structure were not clear in some cases. The average maximal thickness of gingiva and epithelium and biologic width at the mandibular anteriors were 1.06 ± 0.21, 0.49 ± 0.15 and 2.09 ± 0.60 mm, respectively.

CONCLUSION

OCT has promise for non-invasive observation of the periodontal tissue profile in detail and measurement of internal periodontal structures including biologic width in the anterior region.

Non-invasive evaluation of facial crestal bone with ultrasonography

Purpose

Facial crestal bone level and dimension determine function and esthetics of dentition and dental implants. We have previously demonstrated that ultrasound can identify bony and soft tissue structures in the oral cavity. The aim of this study is to evaluate the accuracy of using ultrasound to measure facial crestal bone level and thickness.

Materials and methods

A commercially available medical ultrasound scanner, paired with a 14 MHz imaging probe was used to scan dental and periodontal tissues at the mid-facial site of each tooth on 6 fresh cadavers. The alveolar crest level in relation to the cemento-enamel junction and its thickness on ultrasound images were measured and compared to those on cone-beam computed tomography (CBCT) scans and/or direct measurements on a total of 144 teeth.

Results

The mean crestal bone level measured by means of ultrasound, CBCT and direct measures was 2.66 ± 0.86 mm, 2.51 ± 0.82 mm, and 2.71 ± 1.04 mm, respectively. The mean crestal bone thickness was 0.71 ± 0.44 mm and 0.74 ± 0.34 mm, measured by means of ultrasound and CBCT, respectively. The correlations of the ultrasound readings to the other two methods were between 0.78 and 0.88. The mean absolute differences in crestal bone height and thickness between ultrasound and CBCT were 0.09 mm (-1.20 to 1.00 mm, p = 0.06) and 0.03 mm (-0.48 to 0.54 mm, p = 0.03), respectively.

Conclusion

Ultrasound was as accurate in determining alveolar bone level and its thickness as CBCT and direct measurements. Clinical trials will be required to further validate this non-ionizing and non-invasive method for determining facial crestal bone position and dimension.

Non-ionizing real-time ultrasonography in implant and oral surgery: A feasibility study

PURPOSE

Ultrasound imaging has potential to complement radiographic imaging modalities in implant and oral surgery given that it is non-ionizing and provides instantaneous images of anatomical structures. For application in oral and dental imaging, its qualities are dependent on its ability to accurately capture these complex structures. Therefore, the aim of this feasibility study was to investigate ultrasound to image soft tissue, hard tissue surface topography and specific vital structures.

MATERIAL AND METHODS

A clinical ultrasound scanner, paired with two 14-MHz transducers of different sizes (one for extraoral and the other for intraoral scans), was used to scan the following structures on a fresh cadaver: (i) the facial bone surface and soft tissue of maxillary anterior teeth, (ii) the greater palatine foramen; (iii) the mental foramen and (iv) the lingual nerve. Multiple measurements relevant to these structures were made on the ultrasound images and compared to those on cone-beam computed tomography (CBCT) scans and/or direct measurements.

RESULTS

Ultrasound imaging could delineate hard tissue surfaces, including enamel, root dentin and bone as well as soft tissue with high resolution (110 μm wavelength). The greater palatine foramen, mental foramen and lingual nerve were clearly shown in ultrasound images. Merging ultrasound and CBCT images demonstrated overall spatial accuracy of ultrasound images, which was corroborated by data gathered from direct measurements.

CONCLUSION

For the first time, this study provides proof-of-concept evidence that ultrasound can be a real-time and non-invasive alternative for the evaluation of oral and dental anatomical structures relevant for implant and oral surgery.

Keratinized Gingiva Height Increases After Alveolar Corticotomy and Augmentation Bone Grafting

BACKGROUND

The aim of the present study is to compare the keratinized gingival tissue (KT) height labial to the mandibular incisors after active orthodontic treatment (AOT) with and without alveolar corticotomy and bone grafting.

METHODS

Two orthodontically treated groups of 35 patients each, with (Cort) and without (Conv) alveolar decortication and augmentation bone grafting, are matched in this case-control study for sample size, sex, mandibular premolar extractions, pretreatment age, post-treatment observation period, and pretreatment KT height. Standardized digital frontal occlusion photographs taken before and at least 1 year after AOT were adjusted to 96 dots per inch and measured with image analysis software for vertical KT height labial to each mandibular incisor.

RESULTS

An average of 1.5 years after completion of AOT, KT height had increased significantly by 0.78 mm (P < 0.001) in the Cort group and decreased 0.38 mm (P = 0.002) in the Conv group; a 1.28-mm KT height gain was demonstrated in the subgroup representing the lowest half of Cort KT height at pretreatment. Mandibular incisor inclination and prominence explained neither the decrease in KT height in Conv nor the KT height gain in Cort.

CONCLUSIONS

Orthodontic therapy combined with alveolar decortication and augmentation bone grafting resulted in a significant increase in KT height. Although KT height surrounding the dentition has been devalued by evidence-based studies, the value-added protection of KT height increase after decortication and augmentation bone grafting offsets the concerns of orthodontic proclination or expanding mandibular incisors facially.

Cone-beam computed tomography as a diagnostic method for determination of gingival thickness and distance between gingival margin and bone crest

The objective of the present study was to assess cone-beam computed tomography (CBCT) as a diagnostic method for determination of gingival thickness (GT) and distance between gingival margin and vestibular (GMBC-V) and interproximal bone crests (GMBC-I). GT and GMBC-V were measured in 348 teeth and GMBC-I was measured in 377 tooth regions of 29 patients with gummy smile. GT was assessed using transgingival probing (TP), ultrasound (US), and CBCT, whereas GMBC-V and GMBC-I were assessed by transsurgical clinical evaluation (TCE) and CBCT. Statistical analyses used independent t-test, Pearson's correlation coefficient, and simple linear regression. Difference was observed for GT: between TP, CBCT, and US considering all teeth; between TP and CBCT and between TP and US in incisors and canines; between TP and US in premolars and first molars. TP presented the highest means for GT. Positive correlation and linear regression were observed between TP and CBCT, TP and US, and CBCT and US. Difference was observed for GMBC-V and GMBC-I using TCE and CBCT, considering all teeth. Correlation and linear regression results were significant for GMBC-V and GMBC-I in incisors, canines, and premolars. CBCT is an effective diagnostic method to visualize and measure GT, GMBC-V, and GMBC-I.

Recent advances of ultrasound imaging in dentistry--a review of the literature

Ultrasonography as an imaging modality in dentistry has been extensively explored in recent years due to several advantages that diagnostic ultrasound provides. It is a non-invasive, inexpensive, painless method and unlike X-ray, it does not cause harmful ionizing radiation. Ultrasound has a promising future as a diagnostic imaging tool in all specialties in dentistry, for both hard and soft tissue detection. The aim of this review is to provide the scientific community and clinicians with an overview of the most recent advances of ultrasound imaging in dentistry. The use of ultrasound is described and discussed in the fields of dental scanning, caries detection, dental fractures, soft tissue and periapical lesions, maxillofacial fractures, periodontal bony defects, gingival and muscle thickness, temporomandibular disorders, and implant dentistry.

Thickness of palatal masticatory mucosa and its relationship with different parameters in Turkish subjects

BACKGROUND

The aim of the study was to clinically investigate the mucosal variations in different parts of hard palate subject to soft tissue harvesting and its relationship with selected parameters in patients with gingival recessions.

MATERIALS & METHODS

Fifty periodontally healthy, dentate subjects (13 males) with gingival recessions were enrolled into the study. After initial periodontal therapy they were scheduled for surgical procedures. Palatal masticatory mucosa of five teeth was evaluated at five different points from the gingival margin and two points on the buccal gingival mucosa were evaluated on the day of surgical intervention via bone sounding method. Totally 27 assessments were performed for each patient.

RESULTS

The overall mean thickness of palatal masticatory mucosa (PMM) was 2.55±0.49mm. The mean mid-facial gingival thickness was 1.11±0.39mm. The PMM showed an increase towards the posterior and raphe palatina. No difference was observed between genders, and no association of body mass index (BMI) and age with PMM was determined. An association was observed between the thicknesses of mid-facial gingival and palatal masticatory mucosa.

CONCLUSION

The thickness of PMM in this study seems to be less than other reports possibly due to ethnicity or measurement design. Canine and premolar region reveals higher thickness values, and the increase in the tissue thickness towards the midline should also been taken into consideration. Clinicians planning soft tissue harvesting from the palate should take this variation into consideration. In this regard transmucosal probing of the donor site may provide valuable information where considerable variation exists.

Relationships between different tooth shapes and patient's periodontal phenotype

BACKGROUND AND OBJECTIVE

The purpose of the present study was to establish whether any correlation exists between tooth shapes and patient-related factors such as gingival and periodontal characteristics.

MATERIAL AND METHODS

Clinical measurements, including the width and the height of maxillary central incisor crowns, the apico incisal height of the keratinized mucosa (KM), the buccal gingival thickness (GT), the depth of the sulcus (SD), the bone-sounding depth (BS) and the height of the interproximal maxillary central papilla (Ph), were investigated in 50 healthy individuals. These individuals were then divided into three groups based on the shape of their maxillary central incisor crowns: triangular; square; or square-tapered. The three groups were analyzed to determine any significant differences among the groups in the values obtained for clinical measurements.

RESULTS

There were no significant differences among the three groups in terms of the SD (p = 0.11) or the BS (p = 0.54), whilst statistically significant differences were observed for the KM (p < 0.001), the GT (p = 0.012) and the Ph (p < 0.001).

CONCLUSION

The results of this study indicate that different tooth shapes are associated with significantly different values for the extent of the KM, its bucco-lingual thickness and the height of the interproximal maxillary central papilla.

Measurement of gingival thickness using digital vernier caliper and ultrasonographic method: a comparative study

BACKGROUND

The measurement of the thickness of the gingival tissues has been done using different techniques. Trans-gingival probing with a graduated probe, use of vernier calipers, ultrasonography and cone-beam computed tomography (CBCT), have all been tried, but no one technique has been shown to be consistent and better than the others. The present study was done to evaluate and compare the gingival thickness as measured with a digital vernier caliper and ultrasonography.

METHODS

A total of 30 systemically healthy, non-smokers were included in the study. The gingival measurements were made and recorded from the maxillary and mandibular lateral incisor areas at 2 locations: (a) at a point apical to the free gingival groove; and (b) at a point immediately coronal to the muco-gingival junction.

RESULTS

The mean gingival thickness ranged from 0.56 to 1.02 mm. Males had a significantly thicker gingiva as compared to females (P < 0.10). Significant differences were not observed when the measurements made using the digital vernier caliper and those made with ultrasonography were compared.

CONCLUSIONS

The thickness of the gingiva was in the range of 0.56-1.02 mm. A digital vernier caliper and ultrasonography both can be used to assess the gingival thickness with equal accuracy.

Intraoral ultrasonography: development of a specific high-frequency probe and clinical pilot study

Although ultrasonography is a non-invasive, inexpensive and painless diagnostic tool for soft tissue imaging, this technique is not currently used for oral exploration. Therefore, we developed a 25-MHz high-frequency ultrasound probe, specially designed for intraoral applications. This paper aims to present clinical intraoral ultrasound images actually interpretable, in order to identify the relevant applications of this novel tool and to design future oral studies. Two independent radiologists performed ultrasound examinations on three healthy volunteers. All the teeth were explored on the lingual and buccal sides (162 samples) to evaluate the ergonomics of the system and the visualisation of anatomic structures. Osseointegrated dental implants and a mucocele were also scanned. At the gingivodental junction of the maxillary and mandibular teeth, the device clearly identifies the tooth surfaces, the alveolar bone reflection with its surrounding subepithelial connective tissue of the gingiva and the gingival epithelia. The bone level and the thickness of soft tissue around the implant are measurable on the buccal and lingual sides. Therefore, intraoral ultrasonography provides additional morphological information that is not accessible by conventional dental x-rays. We propose a novel diagnostic tool that explores the biological width and is able to define the thin or thick nature of the gums. Moreover, intraoral ultrasonography may help to monitor precancerous lesions. This promising device requires large-scale clinical studies to determine whether it should remain a research tool or be used as a diagnostic tool for daily dental practice.

The gingival biotype revisited: transparency of the periodontal probe through the gingival margin as a method to discriminate thin from thick gingiva

AIM

To detect groups of subjects in a sample of 100 periodontally healthy volunteers with different combinations of morphometric data related to central maxillary incisors and surrounding soft tissues.

MATERIAL AND METHODS

Four clinical parameters were included in a cluster analysis: crown width/crown length ratio (CW/CL), gingival width (GW), papilla height (PH) and gingival thickness (GT). The latter was based on the transparency of the periodontal probe through the gingival margin while probing the buccal sulcus. Every first volunteer out of 10 was re-examined to evaluate intra-examiner repeatability for all variables.

RESULTS

High agreement between duplicate recordings was found for all parameters, in particular for GT, pointing to 85% (kappa=0.70; p=0.002). The partitioning method identified three clusters with specific features. Cluster A1 (nine males, 28 females) displayed a slender tooth form (CW/CL=0.79), a GW of 4.92 mm, a PH of 4.29 mm and a thin gingiva (probe visible on one or both incisors in 100% of the subjects). Cluster A2 (29 males, five females) presented similar features (CW/CL=0.77; GW=5.2 mm; PH=4.54 mm), except for GT. These subjects showed a clear thick gingiva (probe concealed on both incisors in 97% of the subjects). The third group (cluster B: 12 males, 17 females) differed substantially from the other clusters in many parameters. These subjects showed a more quadratic tooth form (CW/CL=0.88), a broad zone of keratinized tissue (GW=5.84 mm), low papillae (PH=2.84 mm) and a thick gingiva (probe concealed on both incisors in 83% of the subjects).

CONCLUSIONS

The present analysis, using a simple and reproducible method for GT assessment, confirmed the existence of gingival biotypes. A clear thin gingiva was found in about one-third of the sample in mainly female subjects with slender teeth, a narrow zone of keratinized tissue and a highly scalloped gingival margin corresponding to the features of the previously introduced "thin-scalloped biotype" (cluster A1). A clear thick gingiva was found in about two-thirds of the sample in mainly male subjects. About half of them showed quadratic teeth, a broad zone of keratinized tissue and a flat gingival margin corresponding to the features of the previously introduced "thick-flat biotype" (cluster B). The other half could not be classified as such. These subjects showed a clear thick gingiva with slender teeth, a narrow zone of keratinized tissue and a high gingival scallop (cluster A2).

Breaking biological barriers with a toothbrush

Toothbrushing exposes epithelia and other tissues of the oral cavity to mechanical stress. Here, we investigated whether brushing induces cell wounding--plasma membrane disruption--in epithelial and other cell types in the oral cavity. Brushing of the gingivae and tongues of rats resulted in a striking increase in the number of cells positive for a marker of disruption injury. These cells included those in all strata of the gingival epithelium, and in the skeletal muscle of the tongue. Additionally, we found that brushing resulted in an increase in c-fos expression by junctional epithelial and skeletal muscle cells. Epithelial barrier function, however, was not overtly affected by brushing, despite the observed individual injuries to cells. We concluded that brushing disrupts cell plasma membrane barriers in the oral cavity and activates gene expression events that may lead to local adaptive changes in tissue architecture beneficial to gingival health.

Repeatability of ultrasonic determination of gingival thickness

The aim of the present study was to assess the degree of disagreement of ultrasonic measurements of gingival thickness at different teeth. Gingival thickness was determined in 33 volunteers with plaque-induced gingivitis. Facial/buccal gingiva was measured at the level of the gingival sulcus depth. Measurements were repeated after 2 and 4 weeks. A repeated measures, two-level (occasion, subject), variance components model revealed a within-subject variance of 0.187 mm(2) resulting in a repeatability coefficient of 1.20 mm. When modeling level 1 (occasion) variance as a function of tooth type, respective error terms were used for calculating 95% repeatability coefficients for different teeth. Unreliable measurements were largely confined to upper and lower second and third molars. Error terms were lowest (0.03-0.05) at upper canines and first premolars as well as lower anterior teeth and premolars, where repeatability coefficients of 0.5 to 0.6 mm could be estimated. It was concluded that performance of the device was best at certain tooth types with rather thin gingiva. The present resolution and rather high degree of disagreement may preclude, however, detection of minute increases in thickness in the micrometer range, which seem to occur during gingivitis.

Skeletal bone mineral density in relation to thickness, bone mass, and structure of the mandibular alveolar process in dentate men and women

Peri-apical radiographs have been used to identify women with low bone mineral density (BMD) in various parts of the skeleton, but their usefulness for men has not been elucidated. The aim of this study was to test if the mandibular bone structure and bone mass in men and women were related to the BMD of the forearms, determined by dual X-ray absorptiometry, in 42 men and 42 women (aged 18-84 yr). Mandibular alveolar thickness was measured in casts, and alveolar 'bone mass' was estimated on digital radiographs using gray-shade distribution. Alveolar bone structure was evaluated visually (trabecular pattern) on analog radiographs and with its bone texture on digitized radiographs. Bone texture was correlated to BMD in both men and women. BMD was correlated to alveolar bone mass and trabecular pattern in women, but not in men. Bone texture and body mass index (BMI) explained 57% of the variance in BMD for men, whereas trabecular pattern and age explained 50% of the variance in BMD for women. Sparse trabeculation was associated with osteopenia. We conclude that alveolar bone texture and BMI are predictors of BMD for men, and age and trabecular pattern are predictors of BMD for women.