New putative periodontopathogens and periodontal health-associated species: A systematic review and meta-analysis.

To investigate the existence of any association between new putative periodontal pathogens and periodontitis. Two independent reviewers conducted electronic literature searches in the MEDLINE (PubMed), EMBASE, DOSS and Google Scholar databases as well as a manual search to identify eligible clinical studies prior to November 2022. Studies comparing the prevalence of microorganisms other than the already-known periodontal pathogens in subgingival plaque and/or saliva samples between subjects with periodontitis and subject with periodontal health were included. Meta-analyses were performed on data provided by the included studies. Fifty studies including a total of 2739 periodontitis subjects and 1747 subjects with periodontal health were included. The Archaea domain and 25 bacterial species (Anaeroglobus geminatus, Bacteroidales [G-2] bacterium HMT 274, Desulfobulbus sp. HMT 041, Dialister invisus, Dialister pneumosintes, Eubacterium brachy, Enterococcus faecalis, Eubacterium nodatum, Eubacterium saphenum, Filifactor alocis, Fretibacterium sp. HMT 360, Fretibacterium sp. HMT 362, Mogibacterium timidum, Peptoniphilaceae sp. HMT 113, Peptostreptococcus stomatis, Porphyromonas endodontalis, Slackia exigua, Streptococcus gordonii, Selenomonas sputigena, Treponema amylovorum, Treponema lecithinolyticum, Treponema maltophilum, Treponema medium, Treponema parvum and Treponema socranskii) were found to be statistically significantly associated with periodontitis. Network studies should be conducted to investigate the role of these newly identified periodontitis-associated microorganisms through interspecies interaction and host-microbe crosstalk analyses.

Correlation of Redondovirus and Entamoeba gingivalis Detections in the Human Oral Cavity Suggests That This Amoeba Is Possibly the Redondovirus Host.

The virome of the human oral cavity and the relationships between viruses and diseases such as periodontitis are scarcely deciphered. Redondoviruses were reported in the human oral cavity in 2019, including in periodontitis patients. Here, we aimed at detecting redondoviruses and at searching for a potential viral host in human saliva. Non-stimulated saliva was collected between December 2020 and June 2021. These samples were tested using real-time PCR regarding the presence of redondovirus and Entamoeba gingivalis DNA. Similarity searches were performed using BLAST against eukaryotic and prokaryotic sequences from GenBank. The redondovirus DNA was detected in 46% of the 28 human saliva samples. In addition, short fragments of redondovirus genomes were detected in silico within Entamoeba sequences. Finally, Entamoeba gingivalis DNA was detected in 46% of the 28 saliva samples, with a strong correlation between redondovirus DNA and E. gingivalis DNA detections, in 93% of the cases. Regarded together, these findings and previous ones strongly support the presence of redondoviruses in the human oral cavity and their association to E. gingivalis as their likely host.

Microscopic observations of SARS-CoV-2 like particles in different oral samples.

The emerging coronavirus pneumonia epidemic caused by the SARS-CoV-2 infection has spread rapidly around the world. The main routes of transmission of SARS-CoV-2 are currently recognised as aerosol/droplet inhalation. However, the involvement of the oral cavity in coronavirus disease 2019 (COVID-19) is poorly known. The current data indicates the presence of viral RNA in oral samples, suggesting the implication of saliva in SARS-CoV-2 transmission, however, no direct observation of SARS-CoV-2 particles in different oral samples has been reported. In this study, we investigated whether particles of SARS-CoV-2 were present in oral samples collected from three symptomatic COVID-19 patients. Using scanning electron microscopy (SEM), the correlative strategy of light microscopy and electron microscopy and immunofluorescence staining, we showed the presence of SARS-like particles in RT-qPCR SARS-CoV-2-positive saliva, dental plaque and gingival crevicular fluid (GCF) samples. In the saliva samples, we demonstrated the presence of epithelial oral cells with morphogenetic features of SARS-CoV-2 infected cells. Inside those cells, vacuoles filled with nascent particles were observed, suggesting the potential infection and replication of SARS-CoV-2 in oral tissues. Our results corroborate previous studies and confirm that the oral cavity may be a potential niche for SARS-CoV-2 infection and a potential source of transmission.

Effectiveness of surgical root coverage on dentin hypersensitivity: A systematic review and meta-analysis.

AIM: To assess the effect of surgical root coverage (RC) on dentin hypersensitivity (DH) associated with gingival recession. MATERIALS AND METHODS: Two independent reviewers conducted electronic literature searches in MEDLINE (PubMed), EMBASE, Cochrane Library, Web Of Science, Dentistry & Oral Sciences Source, ScienceDirect, and ClinicalTrials.gov databases as well as a manual search to identify eligible clinical studies from January 2000 to March 2022. Randomized controlled trials (RCTs) comparing two surgical RC techniques or a surgical RC technique with or without adjuvant were included. Meta-analyses were performed on data provided by RCTs. RESULTS: Thirteen RCTs with a total of 701 patients (1086 recessions) were included. The percentage of DH suppression was 70.8% (95% confidence interval [CI] [64.4-76.6]; I2  = 39.2% [3.5-61.8], Q-test = 0.02) after surgical RC. Recession reduction and percentage of RC were both statistically significantly associated with DH suppression (estimate = 0.66 [0.10-1.23], p = .022, R2  = 14.45% and estimate = 0.04 [0.01-0.08], p = .012, R2  = 29.54%, respectively). Coronally advanced flap (CAF) + connective tissue graft showed results statistically more effective than CAF + xenogeneic collagen matrix in DH suppression (73.3% [65.6-79.8] and 61.4% [51.7-70.3], respectively; p = .048). CONCLUSIONS: Success of surgical RC is associated with DH suppression.

Smile Aesthetic Evaluation on Videographs: An Intra-Rater and Inter-Rater Agreement Study.

The aim of this study was to assess on videographs the intra- and inter-rater reproducibility of the Smile Esthetic Index (SEI) that has been previously validated on photographs. Smile videographs were obtained using a smartphone associated with the Smile Lite MDP mounted on a tripod. They were then randomized and evaluated twice consecutively at a 1-week interval by three periodontists according to the SEI based on 10 variables. Cohen's Kappa and Fleiss' Kappa tests were performed to measure intra- and inter-rater agreement. Sixty-five smile videographs of 24 men and 41 women (mean age 33 ± 11.3 years) were scored. A mean intra-rater agreement of 0.68 (0.64-0.73) was obtained, representing substantial agreement. The inter-rater agreement calculated for each variable ranged from 0.31 for the variable "absence of visible excessive gingiva" to 0.90 for the variable "absence of diastema and/or missing inter-dental papilla." Within the limits of this study, we have demonstrated that it was possible to use videographs to reproducibly evaluate an aesthetic score (SEI) previously validated on photographs.

Isolation and characterization of Campylobacter massiliensis sp. nov., a novel Campylobacter species detected in a gingivitis subject.

A Gram-negative bacterium, designated strain Marseille-Q3452T, was isolated from subgingival dental plaque of a subject suffering from dental plaque biofilm-induced gingivitis on an intact periodontium in Marseille, France. The strain was characterized by 16S rRNA and atpA gene sequence analysis and by conventional phenotypic and chemotaxonomic testing. The average nucleotide identity (ANI) and core genome phylogeny were determined using whole-genome sequences. Although strain Marseille-Q3452T showed 99.72 % 16S rRNA gene sequence similarity with Campylobacter showae strain ATCC 51146T, atpA and ANI analyses revealed divergence between the two strains. The two species could also be distinguished phenotypically on the basis of the absence of flagella and nitrate reduction. On the basis of the results from phenotypic, chemotaxonomic, genomic and phylogenetic analyses and data, we concluded that strain Marseille-Q3452T represents a novel species of the genus Campylobacter, for which the name Campylobacter massiliensis sp. nov. is proposed (=CSUR Q3452=CECT 30263).

Isolation and description of Selenomonas timonae sp. nov., a novel Selenomonas species detected in a gingivitis patient.

A Gram-stain-negative bacterium, designated strain Marseille-Q3039T, was isolated from subgingival dental plaque of a woman with gingivitis in Marseille, France. Strain Marseille-Q3039T was found to be an anaerobic, motile and spore-forming crescent-shaped bacterium that grew at 25-41.5 °C (optimum, 37 °C), pH 5.5-8.5 (optimum, pH 7.5) and salinity of 5.0 g l-1 NaCl. The results of 16S rRNA gene sequence analysis revealed that strain Marseille-Q3039T was closely related to Selenomonas infelix ATCC 43532T (98.42 % similarity), Selenomonas dianae ATCC 43527T (97.25 %) and Centipedia periodontii DSM 2778T (97.19 %). The orthologous average nucleotide identity and digital DNA-DNA hybridization relatedness between strain Q3039T and its closest phylogenetic neighbours were respectively 84.57 and 28.2 % for S. infelix ATCC 43532T and 83.93 and 27.2 % for C. periodontii DSM 2778T. The major fatty acids were identified as C13 : 0 (27.7 %), C15 : 0 (24.4 %) and specific C13 : 0 3-OH (12.3 %). Genome sequencing revealed a genome size of 2 351 779 bp and a G+C content of 57.2 mol%. On the basis of the results from phenotypic, chemotaxonomic, genomic and phylogenetic analyses and data, we concluded that strain Marseille-Q3039T represents a novel species of the genus Selenomonas, for which the name Selenomonas timonae sp. nov. is proposed (=CSUR Q3039=CECT 30128).

Isolation and Characterization of Capnocytophaga bilenii sp. nov., a Novel Capnocytophaga Species Detected in a Gingivitis Subject.

Capnocytophaga species are commensal gliding bacteria that are found in human and animal oral microbiota and are involved in several inflammatory diseases, both in immunocompromised and immunocompetent subjects. This study contributes to increased knowledge of this genus by characterizing a novel species isolated from a dental plaque sample in a male with gingivitis. We investigated morphological and chemotaxonomic characteristics using different growth conditions, temperature, and pH. Cellular fatty acid methyl ester (FAME) analysis was employed with gas chromatography/mass spectrometry (GC/MS). Phylogenetic analysis based on 16S rRNA, orthologous average nucleotide identity (OrthoANI), and digital DNA-DNA hybridization (dDDH) relatedness were performed. The Marseille-Q4570T strain was found to be a facultative aerobic, Gram-negative, elongated, round-tipped bacterium that grew at 25-56 °C and tolerated a pH of 5.5 to 8.5 and an NaCl content ranging from 5 to 15 g/L. The most abundant fatty acid was the branched structure 13-methyl-tetradecanoic acid (76%), followed by hexadecanoic acid (6%) and 3-hydroxy-15-methyl-hexadecanoic acid (4%). A 16S rDNA-based similarity analysis showed that the Marseille-Q4570T strain was closely related to Capnocytophaga leadbetteri strain AHN8855T (97.24% sequence identity). The OrthoANI and dDDH values between these two strains were, respectively, 76.81% and 25.6%. Therefore, we conclude that the Marseille-Q4570T strain represents a novel species of the genus Capnocytophaga, for which the name Capnocytophaga bilenii sp. nov. is proposed (=CSUR Q4570).

Isolation and Description of Catonella massiliensis sp. nov., a Novel Catonella Species, Isolated from a Stable Periodontitis Subject.

The genus Catonella currently counts a unique species, C. morbi, isolated from periodontal pockets and associated with periodontitis and endodontic infections. This study contributed to the taxonomical and clinical knowledge of this genus by describing a novel species isolated from a saliva sample from a man in clinical gingival health following successful treatment of periodontitis. Morphological and chemotaxonomic characteristics were investigated using different growth conditions, pH, and temperature. Cellular fatty acid methyl ester (FAME) analysis was conducted by gas chromatography/mass spectrometry (GC/MS). Phylogenetic analysis based on 16S rRNA, orthologous average nucleotide identity (OrthoANI), and digital DNA-DNA hybridization (dDDH) relatedness were performed. Strain Marseille-Q4567T was found to be an anaerobic and non-spore-forming rod-shaped bacterium that grew at 28-41.5 °C (optimum 37 °C), pH 6.5-8.5 (optimum pH 7.5), and 5-10 g/L of NaCl (optimum 5 g/L). The predominant cellular fatty acid was C16:0 (64.2%), followed by unsaturated structures C18:1n9 (12.5%) and C18:2n6 (7.8%). Based on 16S rRNA sequence comparison, the closest phylogenetic neighbor was C. morbi ATCC 51271T (98.23% similarity). The OrthoANI and dDDH values between strain Q4567T and C. morbi ATCC 51271T were respectively 79.43% and 23.8%. Therefore, we concluded that strain Marseille-Q4567T represents a novel species of the genus Catonella, for which the name Catonella massiliensis sp. nov. is proposed (= CSUR Q4567).

Isolation and Characterization of Kingella bonacorsii sp. nov., A Novel Kingella Species Detected in a Stable Periodontitis Subject.

Members of the genus Kingella are mostly commensals of the oral cavity, but some of them are involved in invasive infections, especially in young children. This study provides new knowledge on the diversity of this genus by describing a novel species of Kingella isolated from a dental plaque sample from a 51-year-old man with a history of periodontitis. Morphological and chemotaxonomic characteristic were investigated using different growth conditions, pH and temperature. Cellular fatty acid methyl ester (FAME) analysis was performed by gas chromatography/mass spectrometry (GC/MS). Phylogenetic analysis based on 16S rRNA, orthologous average nucleotide identity (OrthoANI) and digital DNA-DNA hybridization (dDDH) relatedness were also performed. Strain Marseille-Q4569T was found to be a facultative aerobic, nonmotile and non-spore-forming rod-shaped bacterium that grows at 28-41.5 °C (optimum 37 °C), pH 5.5-8.5 (optimum pH 7.5) and 5-15 g/L of NaCl. The major fatty acids were Hexadecanoic acid (32.7%), 11-Octadecenoic acid (26.1 %) and 9-Hexadecenoic acid (21.3 %). Despite high 16S rRNA gene sequence similarity (98.72%) between strain Marseille-Q4569T and Kingella oralis strain UB-38T, the degree of OrthoANI was at the limit of the cutoff (95.83%), and the degree of dDDH was lower (63.6%) than thresholds used to delineate prokaryotic species. Therefore, it is proposed that strain Marseille-Q4569T represents a novel species of the genus Kingella, for which the name Kingella bonacorsii sp. nov. is proposed (=CSUR Q4569).

Rapid diagnosis of periodontitis, a feasibility study using MALDI-TOF mass spectrometry.

AIM: The aim of the present study was to assess the feasibility and diagnostic contribution of protein profiling using MALDI-TOF mass spectrometry applied to saliva, gingival crevicular fluid (GCF) and dental plaque from periodontitis and healthy subjects. We hypothesized that rapid routine and blinded MALDI-TOF analysis could accurately classify these three types of samples according to periodontal state. MATERIALS AND METHODS: Unstimulated saliva, GCF and dental plaque, collected from periodontitis subjects and healthy controls, were analyzed by MALDI-TOF MS. Based on the differentially expressed peaks between the two groups, diagnostic decision trees were built for each sample. RESULTS: Among 141 patients (67 periodontitis and 74 healthy controls), the decision trees diagnosed periodontitis with a sensitivity = 70.3% (± 0.211) and a specificity = 77.8% (± 0.165) for saliva, a sensitivity = 79.6% (± 0.188) and a specificity = 75.7% (± 0.195) for GCF, and a sensitivity = 72.1% (± 0.202) and a specificity = 72.2% (± 0.195) for dental plaque. The sensitivity and specificity of the tests were improved to 100% (CI 95% = [0.91;1]) and 100% (CI 95% = [0.92;1]), respectively, when two samples were tested. CONCLUSION: We developed, for the first time, diagnostic tests based on protein profiles of saliva, GCF and dental plaque between periodontitis patients and healthy subjects. When at least 2 of these samples were tested, the best results were obtained.

Perioperative management of oral anticoagulated patients undergoing an oral, implant, or periodontal procedure: a survey of practices of members of two dental scientific societies, the PRADICO study.

OBJECTIVES: Studies on the perioperative management of patients on direct oral anticoagulants (DOACs) receiving oral invasive procedures are sparse. Moreover, the recommendations of the scientific societies on DOACs are discordant, and the practices are highly variable. We conducted a survey of general and specialized dentists in France to compare their practices concerning the management of patients receiving vitamin K antagonists (VKAs) and DOACs. MATERIALS AND METHODS: Members of two dental surgical societies were invited to participate in the survey. One hundred forty-one practitioners answered an online questionnaire focusing on the periprocedural management of oral anticoagulated patients (participation rate, 17.8%). RESULTS: Practitioners at hospitals or mixed practices and specialists treated significantly more anticoagulated patients and more frequently performed procedures with high hemorrhagic risk than practitioners with private practice and general dentists. Greater than 90% of practitioners did not modify the treatment for patients on VKAs and controlled the International Normalized Ratio (INR) preoperatively. Regarding DOACs, 62.9% of practitioners did not change the treatment, 70.8% did not prescribe any biological tests, and 13.9% prescribed an INR. Practitioners at hospitals and mixed practices and specialists had better training and knowledge about DOACs. CONCLUSIONS: This survey showed that anticoagulated patients were managed mostly by specialists in private or hospital care, notably when requiring oral procedures at high hemorrhagic risk. CLINICAL RELEVANCE: A growing proportion of anticoagulated patients are being treated by dentists in primary care. Consequently, they need training, especially concerning DOACs. Additionally, consensus recommendations are necessary for better coordination of stakeholders and patient safety. Trial registration on ClinicalTrials.gov : NCT03150303.

[Oral and periodontal hygiene in orthodontic patients]. / Hygiène orale et parodontale chez les patients porteurs de dispositifs orthodontiques.

INTRODUCTION: Orthodontic appliances promote dental plaque retention and make tooth-brushing less easy. They result in both quantitative and qualitative changes in dental plaque, exposing orthodontic patients to dental caries and periodontal diseases. MATERIALS AND METHODS: The authors explain the effects of orthodontic treatments on dental plaque and the occurrence of dental and periodontal problems; they emphasize the role of pathogenic bacteria and highlight the need for efficient (both individual and professional) control of dental plaque. DISCUSSION: Therefore, orthodontists have to educate their patients on oral and periodontal hygiene in order to control this bacterial factor and to avoid the occurrence of dental and/or periodontal complications.

[Perfecting smile esthetics: keep it pink!] / Comment parfaire l'esthétique du sourire : toujours en rose !

INTRODUCTION: Smile aesthetics is based on numerical, physical, physiological and psychological data regarding beauty, while taking into account the desires of the patient. It is determined by the shape, colour and position of the lips, teeth and gingival tissues. Periodontal examination in both the facial and labial settings supports analysis of the gingival display during natural and forced smiling, the health of the periodontium, the gingival contours, the aesthetic gingival line, and the presence of the papillae. MATERIALS AND METHODS: All these data will help establish a gingival aesthetic score to determine the causes of disharmony and possible treatment. DISCUSSION: During implementation of the global orthodontic treatment plan, periodontal plastic surgery can change the gingival appearance and morphology in order to restore the harmony of the smile. Subtractive periodontal plastic surgery treats biological space defects and excess tissue during incomplete passive eruption by gingivectomy or apically positioned flap, combined, or not, with osteoplasty or osteoectomy. Finally, injections of hyaluronic acid in the papillae can plump them up and minimize the size of any black holes.

[Reason for failure in the treatment of impacted and retained teeth]. / Échec de la mise en place de dents retenues et incluses.

The positioning of an impacted or retained tooth in either children or adults presents a real challenge for the two practitioners involved, the orthodontist and the surgeon in charge of the surgical exposure. The maxillary canine is the tooth most often impacted in the anterior segment, with a prevalence of 2% in the general population. One can understand, therefore, the functional and esthetic challenge for the surgical-orthodontic team whose aim will be to reposition the impacted or retained tooth in the arch. A large number of mistakes must be avoided in order to achieve a satisfactory result for both the patient and the practitioner. Modern imaging techniques should be used to obtain a precise diagnosis of the location of the tooth and to perform surgery which will spare the tooth in question as well as the surrounding anatomic structures. The directions and forces of the traction used will need to be carefully thought out in order to move the tooth into its final position on the arch in optimal conditions. The periodontal setting will be optimized and checked at every step of the treatment. The aim, in fact, is to anticipate the onset of periodontal problems on the grounds that prevention is easier than cure.

[Behavior of the periodontium during leveling of the mandibular incisors: what precautions are needed?]. / Comportement du parodonte au cours du nivellement des incisives mandibulaires : précautions à prendre∗.

Since the position of the mandibular incisors is one of the keys to successful treatment, most orthodontic treatments focus on control but take no special precautions regarding the periodontal environment. Can we trust the lateral headfilm alone when evaluating such slender quantities of bone surrounding the mandibular incisors? What is the true bone situation prior to treatment and above all, following alignment, leveling and uprighting of the incisors? We performed a prospective 3-year study on 50 patients to assess the periodontal behavior of the mandibular incisors following a leveling phase by means of a clinical approach using periodontal and radiologic probing based on measurements of bone thickness obtained by cone beam. The bone loss observed was not inconsiderable given the thinness of the initial bone. In the face of this clinical situation, we need to adapt our treatment by performing a pre-orthodontic periodontal check-up and by supplementing the diagnosis with 3D examinations for at-risk patients and by checking the incisal axes during the leveling phase. The advent of cone beam has provided us with a valuable tool making it possible to individualize orthodontic treatment and view the posttreatment bone environment and root positions.

[Reciprocal relationships between orthodontics and periodontics in esthetic treatments]. / Apport de la parodontologie dans l'esthétique du sourire.

The objective of this article is to review various unsightly periodontal defects and the treatments that have previously been used to eliminate them in order to establish guidelines for future therapy. The inter-relationship between orthodontic and periodontal disciplines is well established and needs no defense here. Periodontal tissues change throughout life and the same is true for the smile. The periodontium is an essential component of the appearance of the face as well as the lips. These are dynamic esthetic criteria while the gingiva and the static character of the dentition also contribute to the character of an individual's smile. In order to conduct orthodontic therapy most effectively it is essential that orthodontists and periodontists utilize a coordinated approach. From the beginning, they must establish an etiological diagnosis of any esthetic defects that will insure that their joint therapy is conducted appropriately and at the proper moment.

Do membrane undulations help cells probe the world?

Cells sense physical properties of their environment including substratum rigidity, roughness, and topography of recognition sites. The cell surface displays continuous deformations of nanometer-scale amplitude and Hz frequency. Recent results support the hypothesis that these surface undulations constitute a powerful strategy for the rapid acquisition of environmental cues: transient contact with surroundings generates forces of piconewton intensity as a result of rapid formation and dissociation of intermolecular bonds. The combination of binding and steric forces is expected to drive conformational changes and lateral reorganization of membrane biomolecules, thus generating signaling cascades. We propose that spontaneous membrane mobility shapes the initial information generated by cell-to-surface contacts, and thereby biases later consequences of these interactions.

Qualitative cosmetic evaluation after root-coverage procedures.

BACKGROUND: The purpose of the present study was to evaluate the esthetic outcome using four categories of root-coverage procedures (pedicle soft tissue grafts, non-submerged grafts, submerged grafts, and envelope techniques) and to identify factors associated with esthetic assessment. METHODS: A professional panel of three observers (two periodontists and one control) used a before-after panel scoring system to evaluate the esthetics of 162 root-coverage surgeries. A five-point ordinal scale was used to evaluate the overall esthetic improvement and seven variables that may be considered in the assessment. RESULTS: The intraobserver agreement of the two trained periodontists for the overall cosmetic assessment was almost perfect (kappa = 0.83), and substantial agreement was found between them (kappa = 0.68). Good to excellent overall esthetic results were found by the professionals and control in >70% of the surgical procedures. Analysis of variance indicated a statistical difference between the non-submerged grafts category and the three other surgical categories (P <10(-3)). Multivariate analysis showed that the degree of root coverage was not a significant predictive factor, whereas soft tissue appearance variables and the follow-up were significantly associated with cosmetic assessment. CONCLUSIONS: The present study demonstrated that non-submerged grafts are not recommended in cases of esthetic demand. Future root-coverage trials, basing their justification on esthetics, should include overall qualitative evaluation as the primary variable. The follow-up period should not be <12 months. The before-after panel scoring system is a tool that can be used to evaluate cosmetic outcomes.

Gingival contour assessment: clinical parameters useful for esthetic diagnosis and treatment.

BACKGROUND: The purposes of this study were to quantify some clinical parameters that are useful as esthetic guidelines when the gingival contour is modified and to compare the left and right sides of the six maxillary anterior teeth. METHODS: Maxillary casts mounted on an articulator according to the axis orbital plane were photographed from 103 young adults. The angle formed between the gingival line and the maxillary midline (GLA) and the distance between the gingival zenith of the lateral incisor and the gingival line (LID) were measured. The asymmetry was evaluated using a paired t test for the left versus right measurements of GLA and LID. The descriptive statistics for GLA and LID were calculated. RESULTS: The GLA measurements of the left side (86.5 degrees +/- 5.1 degrees ) were significantly greater than those of the right side (85.2 degrees +/- 4.9 degrees ), and the mean absolute asymmetry for GLA was 4.1 degrees +/- 3.0 degrees . The mean LID measurement was 0.68 +/- 0.52 mm. CONCLUSIONS: The gingival zenith of the canine is apical to the gingival zenith of the incisors (GLA <90 degrees ), and the gingival zenith of the lateral incisor is below (81.1%) or on (15%) the gingival line when the head is oriented in the axis orbital plane. A directional asymmetry was shown, with the right side higher than the left side. Along with other parameters related to dental esthetics, these clinical parameters applied to the gingival contours may serve as esthetic guidelines and may enable us to obtain a more predictable esthetic outcome.