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

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

Tomographic sagittal root position in relation to maxillary anterior bone housing in a Brazilian population.

Purpose: This cross-sectional study evaluated and categorized the tomographic sagittal root position (SRP) of the maxillary anterior teeth in a Brazilian population. Materials and Methods: Cone-beam computed tomographic scans of 420 maxillary anterior teeth of 70 patients (35 men and 35 women, mean age 25.2±5.9 years) were evaluated. The SRP was classified as class I, II, III, or IV. In class I, the root is positioned against the buccal cortical plate; in class II, the root is centered in the middle of the alveolar housing; in class III, the root is positioned against the palatal cortical plate; and in class IV, at least two-thirds of the root engage both the buccal and palatal cortical plates. Results: In total, 274 teeth (65.2%) were class I, 39 (9.3%) were class II, 3 (0.7%) were class III, and 104 (24.8%) were class IV. The frequency distribution over the teeth groups was different from the overall analysis. Important differences were found in the frequencies of classes I, II, and IV compared to other populations. Sex was not associated with the SRP classes (P=0.307). Age distribution was significantly different over the classes (P=0.004). Conclusion: The findings of this study on the distribution of SRP classes among the Brazilian population compared to other populations demonstrate that the SRP should be analyzed on a case-by-case basis for an accurate treatment plan in the maxillary anterior area.

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

BACKGROUND: This cross-sectional study assessed the role of gingival landmarks (GLs) and cutting points (CPs) for gingival phenotype (GP) determination. METHODS: Six maxillary anterior teeth (70 subjects) were evaluated using soft tissue cone-beam computed tomography (ST-CBCT). Gingival thickness was measured at different GLs: 1) tissue zone (gingival margin [GM], 1 and 2 mm apical to GM, cemento-enamel junction, above the bone crest); 2) bone zone (buccal bone crest [BBC], 1, 2, and 3 mm apical to BBC). CPs of 0.6, 0.8, 1.0, 1.2, and 1.5 mm were used to discriminate between thin and thick GP. The clinical determination of GP was made based on transparency of the periodontal probe (TRAN). RESULTS: The prevalence of thin and thick GP depended on the GL and CP. Considering the CP (1 mm), thin GP at the tissue zone ranged from 99% at the GM to 10.2% above the bone crest. In the bone zone, thick GP ranged from 28% at the BBC to 6% at 3 mm apical to the BBC. The predictability of a correct assessment of GP by TRAN compared with ST-CBCT was influenced by the GLs and CPs. A slight agreement (kappa <0.2) and low accuracy (area under the curve <0.7) were found between methods. CONCLUSIONS: The determination of thin and thick GPs is related to the gingival landmarks and CPs. Further studies are required for a well-defined treatment protocol considering different gingival landmarks in tissue and bone zones. An ST-CBCT may be useful for this purpose.

Relationship between smile type and periodontal phenotype: A clinical and tomographic cross-sectional study.

OBJECTIVES: To evaluate the correlation between smile type (ST) and the periodontal phenotype (PP). MATERIAL AND METHODS: Clinical and photographic examinations of 164 participants (48 men and 116 women, mean age 22.9 ± 4.6 years) were performed, including an evaluation of ST (high, average, and low), gingival phenotype (GP) by transparency of the periodontal probe (TRAN), keratinized tissue width (KTW), gingival architecture (GA), tooth shape (TS), and papilla height (PH). A subgroup of 70 participants underwent soft-tissue cone-beam tomographic examinations (ST-CBCT), in which GP, gingival thickness (GT), buccal bone thickness (BBT), and the distances from the gingival margin and cementoenamel junction to the buccal bone crest (GM-BBC and CEJ-BBC) were evaluated. The data were analyzed using one-way ANOVA, Student's t-test, and chi-square tests, with the level of significance set at 0.05. RESULTS: High, average, and low STs were found in 31.7%, 56.7%, and 11.6% of the participants, respectively. Sex (p=0.001), GP evaluated using TRAN (p=0.021) and ST-CBCT scans (p=0.009), GA (p<0.001), and TS (p=0.001), were associated with STs. The prevalence of thin GP was: 63% in low, 50% in average, and 38% in high smile types. KTW (p=0.004), PH (p<0.001), GT at different landmarks (p<0.05), CEJ-BBC (p=0.017), and GM-BBC (p=0.001) were significantly different among STs. The highest GT and KTW were found in the high-smile group, average-smile presented the higher CEJ-BBC while GM-BBC and PH, were higher in low-smile group. CONCLUSION: Periodontal phenotype components presented important difference over the smile types. CLINICAL RELEVANCE: A detailed examination of smile types is an essential part of treatment planning, especially when the patient has high esthetic demands. Clinical and tomographic individual analysis of periodontal phenotypes over the smile types may be helpful for a case-by-case approach, and for the development of well-defined treatment protocols.