Panagiotis Christou

The orthodontic–periodontic interrelationship in integrated treatment challenges: a systematic review

Orthodontic treatment aims at providing an acceptable functional and aesthetic occlusion with appropriate tooth movements. These movements are strongly related to interactions of teeth with their supportive periodontal tissues. In recent years, because of the increased number of adult patients seeking orthodontic treatment, orthodontists frequently face patients with periodontal problems. Aesthetic considerations, like uneven gingival margins or functional problems resulting from inflammatory periodontal diseases should be considered in orthodontic treatment planning. Furthermore, in cases with severe periodontitis, orthodontics may improve the possibilities of saving and restoring a deteriorated dentition. In modern clinical practice, the contribution of the orthodontist, the periodontist and the general dentist is essential for optimized treatment outcomes. The purpose of this systematic review is to highlight the relationship between orthodontics and periodontics in clinical practice and to improve the level of cooperation between dental practitioners. Potentials and limitations that derive from the interdisciplinary approach of complex orthodontic-periodontal clinical problems are discussed.

Vertical growth-related changes in the positions of palatal rugae and maxillary incisors

INTRODUCTION With 3-dimensional scanning, the image of 1 digital dental cast can be superimposed on another to observe growth or treatment changes; however, this requires stable references. The palatal rugae were considered reliable points for detecting dental changes on the casts occlusal plane, but is this the case in the vertical plane? Our aims were to assess the long-term stability of the palatal rugae in the vertical dimension, relate them to possible maxillary incisor posteruptive movements, and validate them as references for the evaluation of longitudinal dental changes. METHODS Four-year longitudinal lateral cephalograms and dental casts of 10 adults and 13 adolescents were used. The median palatal contour of each cast and marks corresponding to each ruga were superimposed on the palate of the cephalograms. Changes in rugae positions during the observation period were measured with respect to the palatal plane. RESULTS Vertical changes were greater for the first rugae (closest to the incisors), less for the second, and even less for the third (farthest from the incisors). The adolescents showed greater vertical changes in rugae position than the adults. There were no statistically significant differences in the anteroposterior changes between the groups. The maxillary central incisor and the first ruga had vertical displacements proportional to the increase of the subjects lower anterior facial height. CONCLUSIONS We found vertical displacement of the maxillary incisor and the rugae during the 4 years of observation in adolescents and adults. The third ruga, the farthest from the incisors, can be used as a reliable reference to assess longitudinal dental changes mainly when growth changes are less prominent.

Geometric morphometric 3D shape analysis and covariation of human mandibular and maxillary first molars

Dental casts of 160 Greek subjects (80 males, 80 females) were scanned by a structured-light scanner. The upper and lower right first molar occlusal surface 3D meshes were processed using geometric morphometric methods. A total of 265 and 274 curve and surface sliding semilandmarks were placed on the upper and lower molar surfaces, respectively. Principal component analysis and partial least square analysis were performed to assess shape parameters. Molars tended to vary between an elongated and a more square form. The first two principal components (PCs), comprising almost 1/3 of molar shape variation, were related to mesiodistal-buccolingual ratios and relative cusp position. Distal cusps displayed the greatest shape variability. Molars of males were larger than those of females (2.8 and 3.2% for upper and lower molars respectively), but no shape dimorphism was observed. Upper and lower molar sizes were significantly correlated (r(2) = 0.689). Allometry was observed for both teeth. Larger lower molars were associated with shorter cusps, expansion of the distal cusp, and constriction of the mesial cusps (predicted variance 3.25%). Upper molars displayed weaker allometry (predicted variance 1.59%). Upper and lower molar shape covariation proved significant (RV = 17.26%, P < 0.0001). The main parameter of molar covariation in partial least square axis 1, contributing to 30% of total covariation, was cusp height, in contrast to the primary variability traits exhibited by PC1 and PC2. The aim of this study was to evaluate shape variation and covariation, including allometry and sexual dimorphism, of maxillary and mandibular first permanent molar occlusal surfaces.

A novel colourimetric technique to assess chewing function using two-coloured specimens: Validation and application

OBJECTIVES Chewing efficiency may be evaluated using cohesive specimen, especially in elderly or dysphagic patients. The aim of this study was to evaluate three two-coloured chewing gums for a colour-mixing ability test and to validate a new purpose built software (ViewGum©). METHODS Dentate participants (dentate-group) and edentulous patients with mandibular two-implant overdentures (IOD-group) were recruited. First, the dentate-group chewed three different types of two-coloured gum (gum1-gum3) for 5, 10, 20, 30 and 50 chewing cycles. Subsequently the number of chewing cycles with the highest intra- and inter-rater agreement was determined visually by applying a scale (SA) and opto-electronically (ViewGum©, Bland-Altman analysis). The ViewGum© software determines semi-automatically the variance of hue (VOH); inadequate mixing presents with larger VOH than complete mixing. Secondly, the dentate-group and the IOD-group were compared. RESULTS The dentate-group comprised 20 participants (10 female, 30.3±6.7 years); the IOD-group 15 participants (10 female, 74.6±8.3 years). Intra-rater and inter-rater agreement (SA) was very high at 20 chewing cycles (95.00-98.75%). Gums 1-3 showed different colour-mixing characteristics as a function of chewing cycles, gum1 showed a logarithmic association; gum2 and gum3 demonstrated more linear behaviours. However, the number of chewing cycles could be predicted in all specimens from VOH (all p<0.0001, mixed linear regression models). Both analyses proved discriminative to the dental state. CONCLUSION ViewGum© proved to be a reliable and discriminative tool to opto-electronically assess chewing efficiency, given an elastic specimen is chewed for 20 cycles and could be recommended for the evaluation of chewing efficiency in a clinical and research setting. CLINICAL SIGNIFICANCE Chewing is a complex function of the oro-facial structures and the central nervous system. The application of the proposed assessments of the chewing function in geriatrics or special care dentistry could help visualising oro-functional or dental comorbidities in dysphagic patients or those suffering from protein-energy malnutrition.

Distances between facial landmarks can be measured accurately with a new digital 3-dimensional video system.

INTRODUCTION The aim of this study was to investigate a new digital 3-dimensional infrared video system to determine its accuracy, precision, and validity in measuring facial distances. METHODS Bench experiments were performed by measuring the vertical and diagonal distances of chessboard squares of known length to determine the systems accuracy and precision. To test the systems validity, 16 healthy volunteers participated in this study. Vertical and horizontal distances of the face were measured electronically at rest, and on posed and aggressive smiles. All measurements were repeated after 8 weeks. Direct measurements of the intercanthal distance were obtained twice with calipers. RESULTS A minor systematic error was found in the bench experiments, with the highest absolute error of 0.227 +/- 0.39 mm. The analysis with this video system showed good reproducibility of all measured distances when the mean of 2 frames was used to compare distances. Digital measurements of the intercanthal distances showed high agreement with the clinically obtained values. CONCLUSIONS This digital video system can measure geometric distances in a 3-dimensional environment with high precision. Facial distances can be measured with good accuracy and precision, allowing applications in research and clinical practice.

Agenesis of maxillary lateral incisor and tooth replacement: cost-effectiveness of different treatment alternatives.

PURPOSE To evaluate the long-term cost-effectiveness of five treatment alternatives for maxillary lateral incisor agenesis where space maintenance and tooth replacement are indicated. MATERIALS AND METHODS The following treatment modalities were considered: single-tooth implant-supported crown, resin-bonded fixed partial denture (FPD), cantilever FPD, full-coverage FPD, and autotransplantation. The cost-effectiveness for each treatment modality was determined as the ratio of the outcome of each modality divided by the cost. Direct costs, clinical and laboratory, were calculated based on national fee schedules and converted to international dollars using purchasing power parity exchange rates. Outcomes were based on the most recently published long-term (10-year) survival rates. Sensitivity analyses were carried out, testing the robustness of the cost-effectiveness analysis. RESULTS The five treatment modalities ranked in the following order from most to least cost-effective: autotransplantation, cantilever FPDs, resin-bonded FPDs, single-tooth implants and implant-supported crowns, and full-coverage FPDs. Sensitivity analysis illustrated that the cost-effectiveness analysis was reliable in identifying autotransplantation as the most and full-coverage FPDs as the least cost-effective treatment modalities. CONCLUSIONS When replacing a missing maxillary lateral incisor, the most costeffective, long-term treatment modality is autotransplantation, whereas the least cost-effective is full-coverage FPDs. However, factors such as patient age, the state of the dentition, occlusion, and tooth conservation should also influence the choice of restoration.

The 100 Most-Cited Human Cleft Lip and Palate–Related Articles Published in Dentistry, Oral Surgery, and Medicine Journals

Objective To identify the 100 most-cited articles pertaining to human cleft lip and palate research published in dentistry, oral surgery, and medicine journals and to identify their principal bibliometric characteristics. Design Web-based bibliometric analysis. Main Outcome Measure The Web of Science was searched to identify the 100 most-cited clinical articles related to cleft lip and/or palate. Information was extracted with regard to total number of citations, number of authors, affiliations, year, and journal of publication, Medical Subject Headings, type of study, specific area of study. Trends in citations were assessed. Results The 100 most-cited articles identified received between 437 and 58 citations. The oldest was published in 1954 and the most recent in 2008. The number of authors ranged from 1 to 12, with an average of three authors per article. Most of the first authors were affiliated with institutions in the United States, with the most prolific institution being the University of Iowa. More than 70% of the studies appeared in The Cleft Palate–Craniofacial Journal. There was a significant negative correlation between average citations per year and time since publication (P < .001); whereas, a significant positive correlation was observed between average citations per year and number of total citations (P < .001). Conclusions The 100 most-cited articles in human cleft lip and palate research published in dentistry, oral surgery, and medicine journals are listed and characterized. This can be used as a potential knowledge base for specialists in training or to produce relevant knowledge defining the direction of future research.

Gingival changes and secondary tooth eruption in adolescents and adults: a longitudinal retrospective study

INTRODUCTION Our aim was to investigate 8 years of vertical changes of the gingival margin and tooth displacement of maxillary molars and incisors in adolescents and adults. METHODS Twenty-five adolescents and 10 adults were included in this study, with dental casts taken 2 and 10 years after orthodontic treatment. The gingival contour of the teeth was traced digitally using calibrated photographs of the 2 dental casts, and gingival changes were measured on crown superimposition. Eruption of the central incisors and first molar were measured on dental casts after scanning and superimposition on the palatal vault. RESULTS Adults and adolescents presented a mean molar eruption of 0.27 and 0.34 mm and a mean incisor eruption of 0.39 and 0.73 mm, respectively. Adults and adolescents presented a mean molar gingival displacement of respectively 0.34 and 0.77 mm, and the adolescents a mean incisor gingival displacement of 0.44 mm. Correlation between secondary tooth eruption and gingival displacement was obtained only for the incisors in the adolescent group. CONCLUSIONS Adolescents and adults presented apical displacement of the gingival contour of the maxillary first molars, as was the case for maxillary incisors in adolescents. Secondary eruption of maxillary first molars and central incisors continues in adolescents and adults.

Highly cited orthodontic articles from 2000 to 2015

Introduction: Identification of highly cited articles based on the h‐index and its properties is important for the evaluation of the past, present, and future of any research discipline. In this study, we aimed to identify the h‐classic articles in orthodontics. Methods: One search on the Web of Science identified all articles from 2000 to 2015 in the 89 journals indexed by the 2015 InCites Journal Citation Reports in the scientific area “dentistry, oral surgery, and medicine.” A second search was performed in the Web of Science using all mesh terms related to orthodontics. Then, we applied the h‐classic method to select the recent articles with the greatest scientific impact in orthodontics. Results: Eighty articles were considered as h‐classic articles. They were published in 20 of the 89 dental journals of the 2015 InCites Journal Citation Reports list. Only 36 articles appeared in orthodontic journals: 23 in the American Journal of Orthodontics & Dentofacial Orthopedics (28.8%), 7 in The Angle Orthodontist (8.8%), and 6 in European Journal of Orthodontics (7.5%). Thirty‐eight articles originated from Europe, 28 from the Americas, and 14 from the Middle East and Asia. Conclusions: More than half of fundamental orthodontic research is published in nonorthodontic journals showing that our field is currently limited, and interactions with other research fields should be sought to increase orthodontic research importance and appeal. HighlightsThe h‐index measures an articles or authors productivity and citation impact.The 80 most cited orthodontic articles were identified as h‐classics.More than 25% of the orthodontic h‐classics originated from U.S. universities.Scandinavian countries accounted for a third of the articles from Europe.Fewer than half of the orthodontic h‐classics were published in orthodontic journals.

Experiences Of Individuals Concerning Combined Orthodontic and Orthognathic Surgical Treatment: A Qualitative Twitter Analysis

Objective: The aim of this qualitative study was to analyze the content of posts on Twitter in order to gain an in-depth understanding of patients’ thoughts and experiences surrounding orthognathic surgical treatment. Materials and Methods: Using the Twitter search function, with the keywords “jaw surgery,” the 1,000 most recent posts on Twitter with relevance to a combined orthodontic and orthognathic surgical treatment were extracted. After applying relevant inclusion and exclusion criteria, the selected posts were analyzed using thematic analysis by 2 independent investigators. Distinct themes and subthemes were developed. Results: A total of 689 posts were analyzed; the 3 main themes identified in relation to orthognathic surgery were preoperative engagement, postoperative difficulties, and posttreatment satisfaction. Twelve subthemes were also identified, expressing issues such as anticipation or apprehension of the surgical procedure, postoperative pain and edema, dietary restrictions and weight loss, paresthesia, depression, and satisfaction with improvements in appearance and self-confidence. The 6 terms most frequently used in tweets were “recovery,” “braces,” “swollen,” “eat,” “liquid diet,” and “pain.” Conclusions: The findings from the present study can increase the awareness of clinicians involved in the combined orthodontic and orthognathic surgical treatment of patients with dentofacial deformities, allowing them to better educate and counsel their patients throughout the entire treatment process.