Morphometric Variation in Maxillary Central Incisors and Its Influence on Gingival Characteristics: A Preliminary Epidemiologic Study in an Indian Population

The presence of interdental papilla between the maxillary central incisors has a considerable influence on harmonizing esthetics and biologic functions. Preliminary investigations indicate an association between tooth shapes and periodontal characteristics. This study aimed to evaluate the prevalence of morphologic variation in maxillary central incisors and its influence on gingival characteristics. It was determined that varied crown forms have a definite influence on gingival characteristics, which could act as a valuable guideline in periodontal, restorative, and anterior implant placement procedures.

Influence of a Laser-Lok Surface on Immediate Functional Loading of Implants in Single-Tooth Replacement: Three-Year Results of a Prospective Randomized Clinical Study on Soft Tissue Response and Esthetics

The purpose of the present prospective randomized study was to evaluate the influence of Laser-Lok microtextured surface on soft tissue peri-implant parameters and esthetics around immediate, functionally loaded implants for single-tooth replacement in the esthetic zone. This study included 77 patients divided into two groups based on different implants used: the control group had BioHorizons tapered internal non-Laser-Lok-type implants (NLL; n = 39) and the test group had BioHorizons tapered internal Laser-Lok-type implants (LL; n = 39). Outcome measures were survival, radiographic marginal bone-level changes, soft tissue parameters, and esthetics. One implant was lost in the test group and one in the control group, for a total survival rate of 96.1% after 3 years. Radiographically, mean crestal bone loss ± standard deviation was 0.59 ± 0.27 mm in the LL group compared with 1.17 ± 0.31 mm in the NLL group. A mean gain in papilla level of 0.41 ± 0.34 mm and 0.17 ± 0.36 mm was observed in the LL and the NLL groups, respectively, while the level of the midfacial peri-implant mucosa remained stable in both groups with no statistically significant differences (0.08 ± 0.42 mm for the LL group vs 0.06 ± 0.36 mm for the NLL group). The mean probing depth values in the LL and NLL groups were 0.58 ± 0.2 mm and 1.89 ± 0.3 mm, respectively. Within the limitations of this study, it was demonstrated that the clinical and esthetic outcome of immediate functional loading was more favorable for LL implants than for NLL implants.

Influence of horizontal dimensions around single gap and adjacent zirconia implants on the papilla - a cross-sectional survey

PURPOSE

To evaluate a possible association between the inter-implant distance and the papilla deficit. Additionally, the effect of high or low contact points of the crowns on the papilla deficit was investigated.

MATERIALS AND METHODS

Periapical radiographs taken 1 year after loading were used to assess the distance from the shoulder of the implant to the adjacent tooth or implant. On the clinical images, the interdental papilla height, soft tissue deficit and crown length were evaluated. The papilla crown proportion and the proportion of the height of the contact point to the crown length were assessed.

RESULTS

Eighty-one patients, with a total of 104 zirconia implants and 208 measurements were involved in this cross-sectional survey. Considering patient means, the correlation between the papilla deficit and the interproximal distance, respectively inter-implant distance, was very low (r = -0.05220; P = 0.6435, N = 81). Logistic regression at implant-level showed that there was no significant difference in the likelihood for a papilla deficit between a high and a low contact point of the crowns with P = 0.8191 (Odds ratio: 1.106 with 95%CI 0.461; 2.654).

CONCLUSIONS

Horizontal interproximal dimensions around zirconia implants showed very weak influence on the papilla height. A high or a low contact point position of the crowns did not affect the papilla deficit. Conflict of Interest and sources of funding: All authors reported no conflict of interest. There were no sources of funding for the research.

Influence of periodontal biotype on the presence of interdental papillae

The absence of interdental papillae can be a negative influence in aesthetics. Periodontal biotype (PB) is one of the factors that can possibly influence this relation and has to be considered in periodontal diagnosis and treatment planning. The objective of this study was to evaluate the influence of the periodontal biotype on the presence and absence of interdental papillae. Forty-seven patients were included in this transversal clinical study. The PB, presence and height of interdental papilla, loss of papillary height, and the distance between the base of the contact point and bone crest (CP-BC) were evaluated. The chi-square test was used to verify the significance level of the PB distribution frequency between groups. The Mann-Whitney test was used to compare the CP-BC measures between the different PB groups, and the correlation test was used to verify the relation between the CP-BC distance and the presence of papillae. The thin PB group presented a significantly higher presence of papillae (71.1%) than did the thick PB group (59.6%, P < 0.05). An inverse and proportional correlation between the CP-BC distance and the presence of papillae was found. The authors concluded that the PB influenced the presence and height of interdental papillae.

[Measurement and analysis of smile line of 62 Han-Chinese]

OBJECTIVE

To analyze smile features in maximum lip-dynamic in Chinese.

METHODS

Sixty-two Han-Chinese, travelling in Germany, with a mean age of 28.5 years were enrolled and photographed. Standardized digital photos were made to measure the height of displayed maxillary gingiva, papilla and tooth during an enjoyment smile. Statistical analysis was performed using Mann-Whitney-U Test and non-parametric analysis.

RESULTS

The mean height of tooth display for the central incisors was 10 mm, with no significant difference between the gender (P > 0.05). The mean height of gingival display was 1.3 mm and the mean papilla height was 3.4 mm. There was no significant difference between the genders (P > 0.05). 31% (19/62) of the subjects belonged to high smile line type, 50% (31/62) to medium smile line type and 19% (12/62) to low smile line type.

CONCLUSIONS

The red esthetics is a paramount factor for Chinese men and women in the esthetic restoration. 81% of the Chinese studied showed various degree of gingival exposure from central incisor to the premolars, which defined the esthetic area for Chinese people. Papilla is a critical parameter for esthetic evaluation and treatment design. The ratio of high smile line in Chinese may be higher than that in Caucasian.

The association between embrasure morphology and central papilla recession: a noninvasive assessment method

BACKGROUND

The distance from bone crest to contact point is only the most frequently studied of the many factors that influence whether interdental papilla are present. The purpose of this study was to discover the association between embrasure morphology and central papilla recession.

METHODS

The central papilla was visually assessed in 310 adults using paralleling periapical radiographs of the maxillary central incisors. The following vertical distances were measured: the recession distance, i.e., papilla tip (PT) to contact point (PT-CP), bone crest (BC) to contact point (BC-CP), proximal cementoenamel junction (pCEJ) to contact point (pCEJ-CP), papilla height (PH), and bone crest to proximal cementoenamel junction (BC-pCEJ). Interdental width was measured horizontally. Subjects were divided into 4 groups according to interdental width and pCEJ-CP distance: long-narrow, short-narrow, long-wide, and short-wide.

RESULTS

Statistical analysis revealed the following for all four study groups: a positive correlation between papilla recession distance and age, a positive correlation between bone crest-contact point distance and age, and a negative correlation between age and papilla height.

CONCLUSION

Central papilla recession as a result of aging occurs most frequently in the long-wide group, that is, among people who have both a wide interdental width and a long distance between the proximal cementoenamel junction and the contact point. However, other factors also affect the likelihood of central papilla recession. Thus, there is a need for further study of the interaction among these causal factors.

Influence of interimplant distance on gingival papilla formation and bone resorption: clinical-radiographic study in dogs

PURPOSE

The purpose of this study was to evaluate in dogs the area between implants after prosthetic restoration within 5 mm distance between the contact point (CP) between crowns and the bone crest (BC).

MATERIALS AND METHODS

The mandibular premolars of 6 dogs were extracted bilaterally. After 12 weeks of healing, each dog received 8 implants. On each side, 2 implants were separated by 2 mm (group 1) and 2 by 3 mm (group 2). After a healing period (3 months), the implants were restored with temporary acrylic resin prostheses and after 4 more weeks, with definitive metallic prostheses. After 8 weeks, the distance between the CP and the papilla (P) was measured. The distance between a line extending from the CP and the gingival height at the distal extension of the prosthesis (DE) was also measured. Digital radiographic images were obtained for evaluation of the CP-BC and BC-P distances and the analysis of bone resorption adjacent to the implant surfaces.

RESULTS

The median CP-P distances were 1.75 mm and 1.98 mm for groups 1 and 2, respectively; the median CP-DE distances were 2.60 and 2.69, respectively. The mean CP-BC distances were 5.64 mm and 6.45 mm, for groups 1 and 2, respectively; mean BC-P distances were 3.07 mm and 3.55 mm, respectively.

DISCUSSION AND CONCLUSIONS

The differences in distances of 2 and 3 mm between implants did not present significant differences in the formation of papillae or in crestal resorption. The CP-BC distances for prostheses should be different from those of natural teeth because in natural teeth, the biologic width is already present, and in the case of implant-supported prostheses, it will develop following second-stage surgery.

The Influence of Anatomical Features on the Outcome of Gingival Recessions Treated With Coronally Advanced Flap and Enamel Matrix Derivative: A 1-Year Prospective Study

BACKGROUND

Coronally advanced flap (CAF) is one of the most effective treatments of Miller Class I and II recessions. Even if excellent outcomes are reported in the literature, complete root coverage is not always predictable, since many surgical and host-related factors may affect the percentage of root coverage obtained. The aim of this clinical study was to evaluate if some anatomical features such as tissue thickness, papillae height and width, recession depth, and vestibular bone height may influence defect coverage of Miller Class I and II gingival recessions treated with CAF in combination with enamel matrix derivative (EMD).

METHODS

Thirty healthy, non-smoking patients (13 men and 17 women; mean age 32.8 +/- 6.2 years) were enrolled. Each patient was treated for one single recession using a CAF with the adjunct of EMD. Clinical parameters at baseline and 6 and 12 months were recorded and compared by using paired Student t test. Data were subdivided in two groups according to the baseline recession depth (REC): REC < 4 mm (group 1) and REC > or = 4 mm (group 2). The relation between the anatomical parameters (papilla height, papilla width, crestal bone height, and flap thickness) and percent of root coverage was evaluated by multiple linear regression analysis.

RESULTS

At 12 months, 91.7% of root coverage was obtained with a mean attachment gain of 3.23 mm. Better results in terms of percentage of root coverage were obtained when the baseline REC was < 4 mm compared to defects > or = 4 mm (96.5% versus 83.5%). Flap thickness was positively correlated to the percentage of root coverage. For gingival recessions > or = 4 mm, 100% root coverage was achieved only when tissue thickness was > or = 1 mm. Root coverage percentage was slightly related to papilla width in both groups, while it was associated with papilla height only in group 1 (P = 0.004). Only in patients in group 1 was the height of bone on the vestibular side related to the percentage of root coverage obtained (P = 0.003).

CONCLUSIONS

The results of the present study suggest that baseline recession depth and flap thickness may influence the outcome of marginal tissue recession therapy with CAF plus EMD at 12 months. There is not a clear relation between root coverage and other anatomical features as papilla width, papilla height, and the amount of bone on the vestibular side.

The influence of the distance from the contact point to the crest of bone on the presence of the interproximal dental papilla

BACKGROUND

Loss of the interproximal dental papilla may cause functional and, especially in the maxillary anterior region, phonetic and severe esthetic problems. The purpose of this study was to investigate whether the distance from the contact point to the bone crest on standardized periapical radiographs of the maxillary anterior teeth could be correlated with the presence of the interproximal papilla in Taiwanese patients.

METHODS

In total, 200 interproximal sites of maxillary anterior teeth in 45 randomly selected patients were examined. Selected subjects were adult Taiwanese with fully erupted permanent dentition. The presence of the interproximal papilla was determined visually. If there was no visible space apical to the contact area, the papilla was recorded as being present. The distance from the contact point to the crest of bone was measured on standardized periapical radiographs using a paralleling technique with a RinnXCP holder.

RESULTS

Data revealed that when the distance from the contact point to the bone crest on standardized periapical radiographs was 5 mm or less, the papillae were almost 100% present. When the distance was 6 mm, 51% of the papillae were present, and when the distance was 7 mm or greater, only 23% of the papillae were present.

CONCLUSION

The distance from the contact point to the bone crest on standardized periapical radiographs of the maxillary anterior teeth is highly associated with the presence or absence of the interproximal papilla in Taiwanese patients, and is a useful guide for clinical evaluation.

Bone morphogenetic protein-7 (osteogenic protein-1, OP-1) and tooth development

Bone morphogenetic proteins (BMPs) form a family of growth factors originally isolated from extracellular bone matrix that are capable of inducing bone formation ectopically. We studied the expression, tissue localization, and function of BMP-7 (OP-1) during tooth development in rodents. Patterns of BMP-7 gene expression and peptide distribution indicated that BMP-7 was present in dental epithelium during the dental lamina, bud, and cap stages. During the bell stage, BMP-7 mRNA expression and protein distribution shifted from dental epithelium toward the dental mesenchyme. With advancing differentiation of odontoblasts, BMP-7 protein staining in the dental papilla became restricted to the layer of fully functional odontoblasts in the process of depositing (pre)dentin. Secretory-stage ameloblasts exhibited weak immunostaining for BMP-7. A restricted pattern of staining in ameloblasts became apparent in post-secretory stages of amelogenesis. Also, cells of the forming periodontal ligament were immunopositive. Histological analysis of tooth development in neonatal BMP-7-deficient mice did not reveal obvious changes compared with wild-type mice. We conclude that, in developing dental tissues, BMP-7 has distribution and expression patterns similar to those of other BMP members but is not an essential growth factor for tooth development, possibly because of functional redundancy with other BMP members or related growth factors.

Temporal and spatial patterns of transforming growth factor-beta 1 expression in developing rat molars

Regulatory peptides of the TGF-beta family affect various aspects of embryonic development. Recent immunolocalization and in situ hybridization studies have demonstrated a specific time- and tissue-dependent expression of TGF-beta 1 in the developing mouse embryo. The purpose of this study was to evaluate the distribution of TGF-beta 1 within rat molars at different stages of development, using a well-characterized antibody, highly specific for TGF-beta 1, and immunohistochemical methods of detection. TGF-beta 1 was immunolocalized intensely within the ectodermally derived stellate reticulum and the mesenchyme of the dental papilla at the bell stage of development. Marked immunostaining was also evident in the papillary layer and the reduced dental organ subjacent to ameloblasts in the differentiation and secretory phases of amelogenesis. During the formation of coronal tissues and in the pre-eruptive phase, immunoreactive TGF-beta 1 was localized conspicuously within the dental follicle overlying the tooth germ. This temporospatial pattern of expression of TGF-beta 1 appears to correlate with specific events in morphogenesis, histogenesis and cytodifferentiation during tooth development.