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Purpose: To analyze the success and survival of splinted and nonsplinted implants. Materials and Methods: A total of 423 patients (n = implants: 888) were included in the study. The success and survival of implants for 15 years were analyzed using a multivariable Cox regression model, and the significant effect of the splinting of prostheses and other risk factors were evaluated. Results: The cumulative success rate was 34.2%: 33.2% in nonsplinted (NS) and 34.8% in splinted implants (SP). The cumulative survival rate was 92.9% (94.1%, NS; 92.3%, SP). Whether to splint was not related to the success and survival of implants. The smaller the implant diameter, the lower the survival rate. The crown length and implant length were significantly associated only with NS implants: The longer the crown length and the shorter the implant length, the greater the risk of implant failure. The emergence angle (EA) and the emergence profile (EP) had a significant effect on only the SP implants: EA3 showed a higher risk than EA1, and EP2 and EP3 had a higher risk of implant failure. Conclusion: Crown length and implant length affected only the nonsplinted implants: The higher the crown length and the shorter the implant length, the greater the risk of implant failure. A significant effect for emergence contour was found only in SP implants: the implants restored with prostheses with EA ≥ 30 degrees on both the mesial and distal sides, and convex EP on at least one side had higher risks of failure. [ABSTRACT FROM AUTHOR]

An assessment of the main morphometric features of the ramets of clones of Scots pine plus trees in a comparative aspect has been carried out. The vegetative progeny of plus trees of the species are represented as part of a clonal plantation created in 2005 in the Dyurtyulinskiy forestry of the forest-steppe zone of the Republic of Bashkortostan in an area with the С2 type of forest growing conditions. Compliance with the breeding and genetic principle of phenotypic assessment of intraand intergroup differences in Scots pine clones and ramets, as well as methodical and methodological requirements for conducting the field stage of the study, has been ensured. Taxation indicators (the height and diameter of the stem, the diameter and length of the crown, the increment of the central shoot in height) have been taken into account for 100 clones at a continuous count. A varying nature of the distribution of the average values of the analyzed stem indicators in the vegetative progeny of plus trees has been revealed. The best growth in stem diameter (25.5±0.73 cm) and height (11.2±0.16 m), as well as central shoot increment (0.45±0.02 m), are typical for the progeny of clones of the plus tree 29/17. Clones 263/40, 264/41, 262/39 with taxation indicators above the average for the entire set of trees in the clone archive are of high breeding value, which indicates the specificity of the genotypes of these specimens. The levels of significance of the differences and the intensity of selection of the best clones of plus trees based on morphometric features have been determined, which indicates the different nature of the individual non-identity of each of the plus trees relative to the rest of the trees studied. The valuable genotypes of the progeny of Scots pine plus trees identified in the clone archive can be recommended for further use in forest seed breeding when creating highly productive and sustainable artificial plantations of this valuable tree species in the region.

In patients with severe alveolar bone resorption on mandibular anterior edentulous areas, it can be difficult to place implants in the location for crowns, and to create the fixed prosthesis having an adequate emergence profile or embrasure, which makes maintenance difficult. Fabricating a removable zirconia prosthesis with a milled bar on poorly positioned implants can be a good option because of easy maintenance. In this case, the patient had severe bone resorption on mandibular anterior region, and large vertical space. We report on the aesthetical and easy-to-maintain results by placing two implants and fabricating a zirconia prosthesis using milled bar. [ABSTRACT FROM AUTHOR]

Objectives: To assess the trueness of digital measurements using direct and indirect scanning approaches compared to the actual clinical measurements. Materials and Methods: The crown length, width, and width/length ratio were measured in 36 anterior maxillary teeth using three different methods. The first was clinically using a digital caliper, the second was by scanning the teeth using a digital scanner and the third was by making an impression of the teeth, constructing a stone cast in the lab, and scanning it to obtain digital measurements. Bland–Altman test and intraclass correlation were used to assess the data and make comparisons. Results: Measurements taken using both approaches were highly reliable, with intraclass correlations ranging from 0.934 to 0.977 (p ≤ 0.000). Bland–Altman plot reflected a minimal mean difference between measurements especially in crown width measurements. Crown width/crown length measurement displayed the highest mean difference. Conclusions: Both direct and indirect optical surface scans showed similar high trueness in linear measurements of teeth. A higher discrepancy was detected in the crown width/length ratio. Clinical Significance: Digital dentistry is the new era in patient management. The use of conventional impression techniques and physical dental casts is associated with several disadvantages. Scanning dental casts to convert physical records into digital ones has multiple advantages. Optical surface scans (digital models) of the dentition are currently being more broadly used and advocated in the different dental disciplines including the construction of surgical guides for esthetic crown lengthening procedures. The trueness and reliability of linear measurements are of paramount importance to allow for proper fit and predictable outcomes. In this study, the trueness of these linear measurements obtained using direct and indirect methods was compared to the actual clinical measurements. [ABSTRACT FROM AUTHOR]

The age, size and morphology of trees, including crown dimensions, can influence crown defoliation. In Croatia, the selection management of silver fir (Abies alba Mill.) forests involves pure or mixed stands, either of which can be affected by various disturbances, resulting in unbalanced stand structures. The aim of this study was to estimate the probability of trees transitioning from one defoliation class to the next, examine the influence of tree attributes on that process and analyze the changes in survival over time. The study was conducted over a 18-year period (1990–2007) on two sites with contrasting stand structures: a uniform stand with a dominant share of silver fir (Site A) and an uneven-aged mixed beech–fir stand (Site B). Logistic regression was used to model tree transitions between defoliation classes. Uniform stand structure increased the likelihood of silver fir trees transitioning to a higher defoliation class, with limited dependence on the tree crown position. In contrast, suppressed and central trees in uneven-aged stands were more likely to transition to a higher defoliation due to greater competition between them. Diameter at breast height (DBH) was found to be a significant predictor of tree transition to higher defoliation classes, with a linear trend of increasing probability with increasing DBH. Crown position and crown length were also found to be significant predictors of changing defoliation class, with observed differences between sites occurring due to differences in stand structure. To ensure a balanced stand structure and enhance tree vitality, careful consideration of easily measurable tree elements such as DBH, crown length, and tree crown position is imperative when selecting trees for felling. [ABSTRACT FROM AUTHOR]

Objectives: The aim of this study is to analyze the esthetic perception of selected canine features, namely crown length, shade, inclination, and angle of incisal edge tip. Materials and methods: The anterior maxillary teeth of a Central European woman were photographed and digitally modified in order to investigate esthetic perceptions of the above four categories. Three groups of examiners with different levels of experience in the field of dentistry (laypersons/inexperienced dental students, advanced dental students, dentists) evaluated the photographs twice with the help of visual analogue scales. Results: The best-evaluated canines have approximately the same length as the central incisor, have the same shade as the other anterior teeth, are best embedded in a lighter overall tooth shade, are neutral to slightly palatal inclined, and have a right angled to rounded incisal edge (≥ 90°). The canines evaluated as least esthetic, however, are longer than the central incisors, darker, inclined labially, and have a tapered incisal edge. No significant differences could be found between the evaluations of the groups with regard to the four feature categories. Conclusions: Laypersons, advanced dental students, and dentists generally evaluate according to the same esthetic standards. Gender does not have a significant influence on evaluation. Clear definitions of esthetically favored shades, incisal edge shapes, inclination, and lengths of the canines can be given. Clinical relevance: Since the esthetics of the smile line play a critical role for patients, dentists, dental technicians, and their supplying industry, knowledge of the esthetically preferred morphology of canines is essential. Clinical significance: The aim of this study is to give clear definitions of esthetically favored shades, incisal edge shapes, and lengths of the canines, as the esthetics of the smile line play a critical role for patients, dentists, dental technicians, and their supplying industry (e.g., denture tooth manufacturers). Precise knowledge of esthetic preferences is important in clinical practice for both dentists and dental technicians, for example, in order to adequately advise patients regarding esthetic corrections. Also, in the case of missing teeth, this knowledge is essential for optimal and satisfactory restorations. Thus, this study can contribute to the satisfaction of general practitioners and patients. [ABSTRACT FROM AUTHOR]

Background and Objectives: The knowledge of the morphology of impacted maxillary central incisors may lead to more effective treatment. Therefore, this systematic review aimed to evaluate the morphology of impacted maxillary central incisors and compare them with contralateral teeth. Material and methods: This systematic review adhered to the PRISMA statement. The literature search was carried out using PubMed (Medline database), Cochrane Library, ProQuest, Web of Science and Science Direct electronic databases with no publication date restrictions up to July 2021. Data assessing the morphology of unilaterally impacted maxillary central incisors (ICI) evaluated with CBCT were extracted, and the quality of the studies was evaluated. Crown length, root length, and root dilaceration of impacted maxillary central incisors were compared with contralateral unimpacted teeth. Results: The initial database search identified a total number of 287 studies. After applying the selection criteria, 21 articles were selected for a full-text analysis, and four retrospective studies involving 205 patients were included in the systematic review. According to the Newcastle-Ottawa Scale (NOS), two of included articles were graded as "Good" and the remaining two as "Fair" quality. The results showed no difference between impacted teeth and their contralateral crowns, or a minor decrease in ICI crown length (from 0.15 to 0.56 mm). The root lengths of impacted maxillary central incisors were considerably shorter than contralateral incisors (from 2.13 to 3.22 mm) and, as dental age increased, root growth decreased and the incidence of root dilaceration was more frequent. Conclusions: The root lengths of impacted maxillary central incisors were considerably shorter compared to the contralateral incisors. Root dilacerations frequency and severity increased as dental age increased. [ABSTRACT FROM AUTHOR]

Background: Teeth morphometrics have been considered to be integral in identifying an individual as it is correlated with the body stature. Aim: The aim of the study was to determine the association between crown length and physical height of children and derive mathematical equations for the prediction of physical height from crown length of primary maxillary anterior teeth. Setting and Design: A dentomorphometric study was carried out among 100 Saudi Arabian children of 3-6 years of age. Maxillary arch impressions were taken for all participants. Clinical crown length and physical height were measured using digital Vernier Caliper and Physician Mechanical Beam Scale, respectively. Regression analysis, correlation analysis and unpaired t-test were performed for data analysis. Results: In female children, a statistically significant moderate positive correlation between primary maxillary right lateral incisor and primary maxillary left central incisor and height of the children, and highly significant association between primary maxillary left lateral incisor and height of the children was found. Whereas for male children, there was a significant moderate positive correlation between primary maxillary right central incisor, primary maxillary right canine and primary maxillary left central incisor with physical height of children. Conclusions: The research has established a significant positive correlation between the clinical crown length and the height of the children in combined sample for teeth numbers 51, 52, 53, 61 and 62. The study has derived the mathematical equations for the prediction of physical height from crown length of few maxillary anterior teeth, for both male and female children. Clinical Significance: The estimation of physical height from the tooth-crown dimensions can prove to be quite beneficial aid in forensic investigations as teeth are resistant to huge traumatic forces such as in case of mass disasters. [ABSTRACT FROM AUTHOR]

Background and Objectives: The knowledge of the morphology of impacted maxillary central incisors may lead to more effective treatment. Therefore, this systematic review aimed to evaluate the morphology of impacted maxillary central incisors and compare them with contralateral teeth. Material and methods: This systematic review adhered to the PRISMA statement. The literature search was carried out using PubMed (Medline database), Cochrane Library, ProQuest, Web of Science and Science Direct electronic databases with no publication date restrictions up to July 2021. Data assessing the morphology of unilaterally impacted maxillary central incisors (ICI) evaluated with CBCT were extracted, and the quality of the studies was evaluated. Crown length, root length, and root dilaceration of impacted maxillary central incisors were compared with contralateral unimpacted teeth. Results: The initial database search identified a total number of 287 studies. After applying the selection criteria, 21 articles were selected for a full-text analysis, and four retrospective studies involving 205 patients were included in the systematic review. According to the Newcastle-Ottawa Scale (NOS), two of included articles were graded as “Good” and the remaining two as “Fair” quality. The results showed no difference between impacted teeth and their contralateral crowns, or a minor decrease in ICI crown length (from 0.15 to 0.56 mm). The root lengths of impacted maxillary central incisors were considerably shorter than contralateral incisors (from 2.13 to 3.22 mm) and, as dental age increased, root growth decreased and the incidence of root dilaceration was more frequent. Conclusions: The root lengths of impacted maxillary central incisors were considerably shorter compared to the contralateral incisors. Root dilacerations frequency and severity increased as dental age increased.

Background Teeth serve many functions, and aesthetics is one of the most important aspects served by teeth, perceived by the limbic system of the human brain. The golden divine ratio is the unique proportion often correlated with beauty. The present study was devised to estimate the dimension of human permanent canines and approximation to the golden divine ratio. Materials and methods The present study included 47 extracted human permanent canines retrieved from the tooth repository of our institute's Department of Oral Biology. Using digital vernier calipers (Themisto TH-M61 digital vernier caliper, 0-150mm/ 6 inch, JIPVI Ecommerce Pvt. Ltd, India, 2022), the following measurements were taken: Mesio-distal and labiolingual dimensions of the crown, crown length, root length, root to crown ratio (R/C) and the tooth to root ratio (T/R). The data were analyzed using Statistical Package for Social Sciences (SPSS) software version 26. Results All the dimensions' mean and standard deviations were calculated for both maxillary and mandibular canines. While the means of mesio-distal and labiolingual dimensions of the crown approximated the values reported in the literature, there was some variation in crown and root lengths. The mean crown lengths of the upper and lower canines were 10.34mm and 9.76mm, respectively, while the root lengths were 16.52 and 15.54mm, respectively. The R/C of both sets and the T/R of the upper canine only followed the golden ratio. T/R of the lower canine was slightly higher (1.64) Conclusion Although the number of included teeth was less, owing to the fact that canines are rarely extracted, our results provided new values of canines for updation in a unique population. More studies are required for comparative anthropological data updates., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2024, Kumar et al.)

• Spruce sapling architecture and growth responses to light and elevation were studied. • Light was a better predictor of sapling growth compared with architecture properties. • Ability of spruce to shape its crown morphology and growth decreased with altitude. • Diameter growth improved under better light conditions regardless of altitude. • Saplings showed negative crown length but not crown width growth in the shade. In their natural environments, trees are able to act adaptively by changing their morphology, functional traits and growth while facing different factors and stimuli. Yet, there is insufficient information on how intraspecific growth and architectural properties vary along elevation gradients, especially for young saplings of tree species regarded as highly important in forestry. We measured the height, diameter, crown growth and several architectural properties of Norway spruce (Picea abies (L.) H. Karst.) saplings along the light gradient in three elevational transects encompassing natural distributions of subalpine spruce forest in two different locations over a 3-year span. We employed generalized linear and mixed models to determine intraspecific differences in spruce architecture and growth responses to light at different elevations. Light was a better predictor of sapling growth compared to architecture properties. At higher altitudes, we observed limited abilities in the spruce saplings to change their crown architecture and enhance their height, crown length and crown width growth with the improvement in light conditions. However, the response of diameter growth to light was well pronounced in all elevational transects. Our results suggested that spruce sapling plasticity in shaping their crown morphology and growth decreased with altitude. Yet, we reported a similar improvement in diameter growth with an improvement in light conditions regardless of altitude. These results raised the question, to what extent do current climatic conditions at upper elevations inhibit Norway spruce diameter growth. We recommend that forest managers increase their efforts to obtain a desirable stem quality and crown shape by regulating light conditions mainly in the middle and lower parts of subalpine forests rather than at the elevational limit of this species. [ABSTRACT FROM AUTHOR]