Evaluation of a vibration modeling technique for the in-vitro measurement of dental implant stability.

The Advanced System for Implant Stability Testing (ASIST) is a device currently being developed to noninvasively measure implant stability by estimating the mechanical stiffness of the bone-implant interface, which is reported as the ASIST Stability Coefficient (ASC). This study's purpose was to determine whether changes in density, bonding, and drilling technique affect the measured vibration of a dental implant, and whether they can be quantified as a change in the estimated BII stiffness. Stability was also measured using RFA, insertion torque (IT) and the pullout test. Bone-level tapered implants (4.1 mm diameter, 10 mm length) were inserted in polyurethane foam as an artificial bone substitute. Samples were prepared using different bone densities (20, 30, 40 PCF), drilling sequences, and superglue to simulate a bonded implant. Measurements were compared across groups at a significance level of 0.05. The ASC was able to indicate changes in each factor as a change in the interfacial stiffness. IT and pullout force values also showed comparable increases. Furthermore, the relative difference in ISQ values between experimental groups was considerably smaller than the ASC. While future work should be done using biological bone and in-vivo systems, the results of this in-vitro study suggest that modelling of the implant system with a vibration-based approach may provide a noninvasive method of assessing the mechanical stability of the implant.

The repeatability of periodontal imaging with intraoral ultrasound scanning.

OBJECTIVE: Ultrasound is a non-invasive and low-cost diagnostic tool widely used in medicine. Recent studies have demonstrated that ultrasound imaging might have the potential to be used intraorally to assess the periodontium by comparing it to current imaging methods. This study aims to characterize the repeatability of intraoral periodontal ultrasound imaging. MATERIALS AND METHODS: Two hundred and twenty-three teeth were scanned from fourteen volunteers participating in this study. One operator conducted all the scans in each tooth thrice with a 20 MHz intraoral ultrasound. The repeatability of three measurements, alveolar bone crest to the cementoenamel junction (ABC-CEJ), gingival thickness (GT), and alveolar bone thickness (ABT), was calculated with intercorrelation coefficient (ICC). Measurements were also compared with mean absolute deviation (MAD), repeatability coefficient (RC), and descriptive statistics. RESULTS: ICC scores for intra-rater repeatability were 0.917(0.897,0.933), 0.849(0.816,0.878), and 0.790(0.746,0.898), MAD results were 0.610 mm (± 0.508), 0.224 (± 0.200), and 0.067 (± 0.060), and RC results were 0.648, 0.327, and 0.121 for ABC-CEJ, GT, and ABT measurements, respectively. CONCLUSION: Results of the present study pointed towards good or excellent repeatability of ultrasound as a measurement tool for periodontal structures. CLINICAL RELEVANCE: Clinicians could benefit from the introduction of a novel chairside diagnostic tool. Ultrasound is a non-invasive imaging assessment tool for the periodontium with promising results in the literature. Further validation, establishment of scanning protocols, and commercialization are still needed before ultrasound imaging is available for clinicians.

An analytical model to measure dental implant stability with the Advanced System for Implant Stability Testing (ASIST).

A non-invasive method of quantitatively assessing dental implant stability is important to monitor its long-term health. The Advanced System for Implant Stability Testing (ASIST) is a noninvasive technique that couples the impact technique with a linear vibration model of the implant system, such that the measured signal can be used to determine a matching analytical response. The purpose of this study was to evaluate the ASIST technique by comparing stability estimates obtained from artificial implant installations with various abutments. Two Straumann dental implants were installed in four densities of uniform polyurethane foam, and the stability of each installation was measured using different healing abutments and artificial dental crowns. With the ASIST, values for the estimated interfacial stiffness increased with foam density and did not significantly change with abutment type for a specific sample. This provides evidence that the analytical model is representative of the physical system. Current methods, such as resonance frequency analysis, interpret the interface stiffness based on a single frequency measurement. With the ASIST, the measured signal provides information about the first and second modes of vibration of the implant system, both of which are influenced by the properties of the corresponding abutment. The consideration of both modes allows the technique to reliably measure the interfacial stiffness independently of the system components. As a result, the ASIST technique may provide an improved non-invasive method of measuring the stability of dental implants.

Use of ultrasound imaging for assessment of the periodontium: A systematic review.

The objective of this study was to systematically review the literature regarding diagnostic applications of ultrasound imaging for evaluation of the periodontium in humans. The search was conducted on Medline, EMBASE, Web of Science, Scopus, Cochrane, and PubMed up to April 3, 2023. The studies included were exclusively human studies that assessed the periodontium with ultrasound (US) imaging (b-mode). Outcomes measured included alveolar bone level, alveolar bone thickness, gingival thickness, and blood flow quantification. References were imported to Covidence. Two reviewers conducted phases 1 and 2. The JBI risk assessment tool for cross-sectional studies was used. Extracted data included the transducer and measurements used and the study's outcomes. The search yielded 4892 studies after removing duplicates. From these, 25 studies were included and selected for extraction. Included studies retrieved outcomes from US examinations of the periodontal tissues. From the selected studies, 15 used US on natural teeth, 4 used US on implants, 2 used US on edentulous ridges, and 4 used color flow/power in US to evaluate the blood flow. The results of the present systematic review suggest that US might be a feasible and valuable diagnostic tool for the periodontium, with the potential to complement shortfalls of current radiographic technologies.

Children's Anxiety Levels and Their Perspectives on Dental Experiences in Students' Clinical Evaluation.

Aim: The purpose of this study is to present a framework for the potential implementation of children's anxiety levels and perspectives of their experiences receiving treatment from dental students through interviews and drawing into the clinical assessment of dental students. Materials and methods: A total of 51 patients between the ages of 5 and 8 years were included in the study. Pulp therapy and/or restorative treatment was performed during the first therapeutic session for all participants. Children were asked to draw about themselves at the dentist's and then verbally explain their drawings. Drawings were analyzed using Child Drawing: Hospital (CD: H) to determine the child's anxiety score. Interviews were analyzed using thematic analysis to establish the factors contributing to the patient having a positive/negative experience. The relationships between the children's level of anxiety and their experience were analyzed using correlation and regression analyses against the student clinical assessment data. Results: Most children in the study exhibited average levels of anxiety and had an overall positive perception of the dentist. The correlation and regression analyses determined that when children presented higher levels of anxiety, the students received statistically significant higher scores in evidence-informed practice (EIP), skills, and their tolerance for error during procedures. No other rubric item was related to the children's anxiety or whether their experience was positive/negative. Conclusion: Although this study provided a framework for exploring children's anxiety levels and perspectives of their experiences in teaching clinical settings, more research is needed to refine the method for student evaluation. Clinical significance: This study will enable dental students to meet the needs of child patients, which consequently increases treatment motivation and adherence to dental services as well as reduces the likelihood of patient anxiety and improves patient self-care skills over time. How to cite this article: Ortiz S, Yoon M, Gibson M, et al. Children's Anxiety Levels and Their Perspectives on Dental Experiences in Students' Clinical Evaluation. Int J Clin Pediatr Dent 2023;16(S-2):S206-S212.

Ultrasound Imaging of the Periodontium Complex: A Reliability Study.

Background: Ultrasonography is a noninvasive, low-cost diagnostic tool widely used in medicine. Recent studies have demonstrated that ultrasound imaging might have the potential to be used intraorally to assess periodontal biomarkers. Objectives: To evaluate the reliability of interlandmark distance measurements on intraoral ultrasound images of the periodontal tissues. Materials and Methods: Sixty-four patients from the graduate periodontics (n = 33) and orthodontics (n = 31) clinics were recruited. A 20 MHz handheld intraoral ultrasound transducer was used to scan maxillary and mandibular incisors, canines, and premolars. Distances between the alveolar bone crest and cementoenamel junction (ABC-CEJ), gingival thickness (GT), and alveolar bone thickness (ABT) were measured by 3 raters. The intercorrelation coefficient (ICC) and mean absolute deviation (MAD) were calculated among and between the raters. Raters also scored images according to quality. Results: The ICC scores for intrarater reliability were 0.940 (0.932-0.947), 0.953 (0.945-0.961), and 0.859 (0.841-0.876) for ABC-CEJ, GT, and ABT, respectively. The intrarater MAD values were 0.023 (±0.019) mm, 0.014 (±0.005) mm, and 0.005 (±0.003) mm, respectively. The ICC scores for interrater reliability were 0.872 (95% CI: 0.836-0.901), 0.958 (95% CI: 0.946-0.968), and 0.836 (95% CI: 0.789-0.873) for ABC-CEJ, GT, and ABT, respectively. The interrater MAD values were 0.063 (±0.029) mm, 0.023 (±0.018) mm, and 0.027 (±0.012) mm, respectively. Conclusions: The present study showed the high reliability of ultrasound in both intrarater and interrater assessments. Results suggest there might be a potential use of intraoral ultrasound to assess periodontium.

The role of Dentin Sialophosphoprotein (DSPP) in craniofacial development.

DSPP is known to be important in the formation of dentin. In DSPP's absence, a severely hypomineralized dentin is formed, in a condition known as dentinogenesis imperfecta (DGI). DSPP has recently been found in several different tissues, including the mandibular condylar cartilage and craniofacial skeleton. However, there is limited literature on the role of DSPP in these tissues. Therefore, the objective of the present study was to investigate the role of DSPP in craniofacial development. Two mice strains, DSPP knockout and C57BL/6J wild type, were compared at 1, 3, and 6-months of age. Skulls and condyles were investigated through morphological and histological analyses. Cell culture was also conducted to investigate the potential effects of DSPP absence in osteoblasts from the calvaria. Mineralization defects were noticed in the structures of skulls and MCC, with the most significant impact at 1 month of age. Therefore, DSPP is an essential protein for the normal mineralization of craniofacial tissues.

Characterization of SIBLING Proteins in the Mineralized Tissues.

The SIBLING proteins are a family of non-collagenous proteins (NCPs) previously thought to be expressed only in dentin but have been demonstrated in other mineralized and non-mineralized tissues. They are believed to play vital roles in both osteogenesis and dentinogenesis. Since they are tightly regulated lifelong processes and involve a peak of mineralization, three different age groups were investigated. Fifteen wild-type (WT) mice were euthanized at ages 1, 3, and 6 months. Hematoxylin and eosin staining (H&E) was performed to localize various microscopic structures in the mice mandibles and tibias. The immunostaining pattern was compared using antibodies for dentin sialoprotein (DSP), dentin matrix protein 1 (DMP1), bone sialoprotein (BSP), and osteopontin (OPN). Immunostaining of DSP in tibia showed its most noticeable staining in the 3-month age group. DSP was expressed in alveolar bone, cellular cementum, and PDL. A similar expression of DMP1 was seen in the tibia and dentin. BSP was most noticeably detected in the tibia and acellular cementum. OPN was mainly expressed in the bone. A lower level of OPN was observed at all age groups in the teeth. The immunostaining intensity was the least detected for all proteins in the 6-month tibia sample. The expression patterns of the four SIBLING proteins showed variations in their staining intensity and temporospatial patterning concordant with skeletal and dental maturity. These findings suggest some role in this tightly regulated mineralization process.

Inflammatory bowel disease and periodontitis: A retrospective chart analysis.

OBJECTIVES: This study examined the variation in prevalence of periodontitis among different sexes, age groups, smoking status, and oral hygiene adherence in patients affected by either Crohn's disease (CD) or ulcerative colitis (UC). MATERIALS & METHODS: This study was a retrospective chart analysis that collected data from the School of Dentistry's Oral Health Clinic at the University of Alberta, Edmonton, Canada. Patients' electronic health records between the years of 2013 and 2019 were analyzed. Multiple keywords such as IBD, CD, UC, and periodontal disease with various spelling combinations were used for searching and gathering pertinent data, which was then further assessed. After applying the inclusion and exclusion criteria, a total of 80 patient charts were included. These patient charts were thoroughly screened to gather information such as age, sex, smoking status, and a variety of periodontal parameters. Collected data were analyzed using SPSS software by using Pearson's χ2 , Pearson's correlation, and Mann-Whitney U-test. RESULTS: IBD had an impact on the severity of periodontitis in patients between the ages of 50 and 64 years with higher odds ratio (OR). Biological sex or history of smoking in IBD patients did not have higher odds of developing periodontitis. Plaque score derived from this retrospective study was used to estimate the patient's oral hygiene status and showed no impact. Also, prevalence of periodontitis did not differ between UC and CD. We anticipated some of these findings because of the retrospective nature of the study. CONCLUSIONS: Within the limitation of the retrospective study, IBD patients in the 50-64 age group years showed a higher odds ratio for a greater prevalence of periodontitis. Thus, a closer periodontal recall and evaluation in these patients is recommended for early diagnosis and preventive care. It is advised that periodontists work closely with gastroenterologists to maintain periodontal health in IBD-affected individuals.

Dental Students' Knowledge, Confidence, Ability, and Self-Reported Difficulties in Periodontal Education: A Mixed Method Pilot Study.

Evidence on periodontal education areas in which students have difficulties and their factors are limited. In this study, third- and fourth-year dental students' knowledge was assessed as well as their confidence and ability in five periodontal educational areas using a mixed-method approach. A survey was used to collect data related to history-taking, medical examination, diagnosis, treatment planning, and follow-up. Student answers were compared to the consensual answers of an expert panel using the cosine-similarity index (CSI). Descriptive statistics assessed confidence and ability for diagnosis. Semi-structured individual interviews were used to collect data on reported reasons for difficulties in periodontal education. A content analysis was employed to analyze the interview data. Eighteen third- and fourth-year dental students completed the survey and eleven were interviewed. Students' knowledge was adequate regarding diagnosis and treatment planning. Third-year students' median CSI were 0.93 and 0.89, respectively. Fourth-year students' median CSI were 0.9 and 0.93, respectively. Students felt confident in history-taking and examination but lacked confidence and ability in diagnosis and treatment planning. Reported reasons for difficulties in periodontal education were linked to both preclinical and clinical pedagogical issues. Further improvements in preclinical and clinical periodontal education are needed to address students' lack of knowledge, confidence, and skills in key periodontal areas.

Failure rates associated with guided versus non-guided dental implant placement: a systematic review and meta-analysis.

OBJECTIVE: The purpose of the systematic review and meta-analysis was to evaluate implant failure rates and their association with guided and free-hand implant placement techniques. MATERIALS AND METHODS: A literature search was conducted across PubMed, Medline via Ovid, Cochrane database, and Google Scholar. The search was completed in September 2020. Series of meta-analyses were conducted to compare implant failure rates with guided and free-hand techniques. RESULTS: A total of 3387 articles were identified from the electronic search. After applying the inclusion criteria, eight articles were selected for qualitative assessment and four for quantitative synthesis (meta-analysis). The included studies had a risk ratio of 0.29 (95% CI: 0.15, 0.58), P < 0.001 for the use of guided implant placement. Implant failure rates were affected by the different placement techniques indicated by the test for overall effect (Z = 3.53, P = 0.0004). The incidence of implant failure in guided surgery versus free-hand surgery was found to be 2.25% and 6.42%, respectively. CONCLUSION: Both guided and free-hand implant placement techniques resulted in a high implant survival rate. However, implant failure rates were almost three times higher in the free-hand implant placement category. A guided implant placement approach is recommended for a successful outcome.

The impact of vaping on periodontitis: A systematic review.

BACKGROUND AND OBJECTIVE: While tobacco cigarette smoking has been proven to be a risk factor for periodontitis, limited information is available regarding vaping, a new alternative to smoking that has been branded as less harmful. Several important in vitro studies have shown that vaping has a similarly damaging effect as cigarette smoking on the health of the periodontium. However, a comprehensive review is lacking in this field. Therefore, we aimed to systematically review the literature about the impact of vaping on periodontitis. METHODS: The research question was created using the PICOs format. A systematic search of the following electronic databases was performed up to March 2020: Medline, Embase, PubMed, Cochrane, and grey literature. Human studies that assessed periodontal status (plaque index, bleeding on probing, clinical attachment loss, marginal bone loss, and probing depth) in e-cigarette users compared to non-smokers (control group) were assessed based on an estimate of fixed effects. The weights of the studies were calculated based on their risks of bias. RESULTS: After duplicates were removed, 1,659 studies were screened and 8 case-control studies that investigated the relationship between vaping and periodontal parameters in humans were selected after their risk of bias assessment. Estimated effects of vaping after weighting results based on their standard deviation showed increased plaque, marginal bone loss, clinical attachment loss, pocket depth, and reduced bleeding on probing. CONCLUSION: This study concluded that there is not enough evidence to fully characterize the impacts of vaping on periodontitis. However, within the limitations of our review and the selected included studies, the available results point to increased destruction of the periodontium leading to the development of the disease.

Antibiotic prophylaxis for implant placement: a systematic review of effects on reduction of implant failure.

Introduction Despite excellent reviews in the past several years, the use of antibiotics as prophylaxis for implant placement remains controversial.Aim To assess the literature on the efficacy of prophylactic antibiotics prescribed prior to and immediately following implant surgery (PIFS).Outcomes Whether administration of antibiotics reduced implant failure and post-operative complications.Design Databases searched were PubMed and Medline via Ovid (1946 to February 2018), Cochrane Library (Wiley) and Google Scholar.Materials and methods Quality assessment, meta-analysis with a forest plot and incorporated assessment of heterogeneity. A two-tailed paired t-test was performed, analysing differences in mean failure rates between groups.Results Fourteen publications were collected; 5,334 implants were placed with pre-operative antibiotics, 82 implants with antibiotics PIFS and 3,862 placed with no antibiotics. The overall risk ratio (RR) was 0.47 (95% CI 0.39-0.58), with the implant failure rates significantly affected by pre-operative intervention (Z = 7.00, P <0.00001). The number needed to treat (NNT) was 35 (95% CI 26.3-48.2). The difference between mean failure rates was statistically significant (P = 0.0335).Conclusion Administering prophylactic antibiotics reduced the risk of implant failures. Further investigations are recommended to establish a standardised protocol for the proper use of antibiotic regimen.

Inhibition of neutrophil inflammatory mediator expression by azithromycin.

BACKGROUND AND OBJECTIVE: Peri-implant tissues appear to exhibit a more vigorous inflammatory response during post-operative healing than periodontal tissues. There is evidence that a single dose of amoxicillin (AMX) prior to implant surgery reduces the risk of early peri-implant healing complications. This study compared the effects of AZM and AMX on neutrophil expression of mRNA for mediators involved in peri-implant healing. MATERIALS AND METHODS: Neutrophils were isolated from healthy human donors and pre-incubated with AZM (4 or 8 µg/ml) or AMX (2 or 4 µg/ml). Cells were then incubated with LPS (1 µg/ml), TNF-α (10 ng/ml), or medium alone (control) for 1, 2, and 4 h. Total RNA was analyzed with qPCR to quantify changes in expression of the six inflammatory mediators. RESULTS: LPS and TNF-α induced a similar pattern of IL-1ß mRNA expression, with peak expression at 1 h. For most mediators, gene expression in neutrophils activated by LPS was markedly reduced in a dose-dependent manner by AZM. Therapeutic concentrations of AZM (8 µg/ml) consistently reduced expression of mediators tested in this study. AMX was effective only in a few cases and under certain conditions. Therefore, AZM was more effective in its direct anti-inflammatory action. CONCLUSION: AZM is a consistent and effective inhibitor of neutrophil inflammatory mediator mRNA expression. CLINICAL RELEVANCE: Given that a single dose of AZM produces higher and more sustained concentrations of this agent in periodontal tissues than AMX when used as a pre-operative prophylactic antibiotic, AZM has greater potential to inhibit inflammatory mediator expression at peri-implant wound sites than AMX.

Surgically accelerated orthodontic techniques and periodontal response: a systematic review.

BACKGROUND: Reduction in orthodontic treatment time is gaining popularity due to patient demands. Several new techniques of acceleratory orthodontic treatment have been introduced to effectively treat the malocclusion in a shorter time period with minimal adverse effects. OBJECTIVE: The objective of this systematic review is to critically evaluate the potential effect of accelerated surgically assisted orthodontic techniques on periodontal tissues. MATERIALS AND METHODS: Electronic databases used to perform the search were Medline (Ovid), EMBASE, PubMed, Scopus, Cochrane, Google Scholar, and hand searching of the literature was also performed. SELECTION CRITERIA: Only randomized control trials (RCTs) that assessed the relationship between accelerated surgically assisted orthodontic techniques and its effects on periodontium were included. DATA COLLECTION AND ANALYSIS: The Joanna Briggs Institute (JBI) critical appraisal checklist tool (2016) was used to assess the finally selected studies. Among these studies, five evaluated corticotomy-facilitated orthodontics, two tested accelerated tooth movement with piezocision, one compared corticotomy-facilitated orthodontics with piezocision, and one studied the effects of periodontally accelerated osteogenic orthodontics. The duration of these studies was relatively short and had moderate to high risk of bias. RESULTS: Literature search identified 225 records from 5 databases and 50 articles from the partial grey literature (Google scholar) search. Finally, nine eligible RCTs were included in the review. LIMITATIONS: Most of the included studies were of a high risk of bias due to high experimental heterogeneity and small sample size. Long-term follow-up of the periodontal response to these interventions was also lacking. CONCLUSIONS: There is an absence of evidence considering the lack of long-term follow-up and small sample size therefore, the results of this review should be carefully interpreted. IMPLICATIONS: Due to the need for more studies with less risk of bias, these techniques should be implemented in dental practice with caution. With stronger evidence, the study may be confirmed to provide quicker desired results for orthodontic patients. REGISTRATION: This study protocol was not registered. FUNDING: No funding was obtained for this systematic review.

Prevalence of Periodontitis in Young Populations: A Systematic Review.

PURPOSE: To assess the prevalence of periodontitis in young populations (previously termed aggressive periodontitis - AgP) and report on the earliest known occurrence of this disease. MATERIALS AND METHODS: A search was performed covering the last 18 years utilising the following databases: Medline (Ovid), PubMed and Embase. Four reviewers evaluated each study. Review findings were summarised using the PRISMA Statement for reporting and Joanna Briggs Institute (JBI) Critical Appraisal tools for quality assessment, respectively. Twenty-two articles were included in this systematic review, consisting of 6 prevalence studies and 16 case reports. Only prevalence studies were considered for prevalence estimates. RESULTS: The average reported prevalence of periodontitis in young populations was 1.7% (ranging from 0.66% in Argentina to 5.9% in Israel). The prevalence was higher for the localised form of this disease. Permanent teeth were the most common dentition affected (114 out of 115 affected patients). In terms of age, the prevalence was 0.6%, 0.8% and 1.6% for the age groups 2-12, 20-25 and 13-20, respectively. There was no significant difference noted between males and females. The earliest age diagnosed with periodontitis was 3 years 7 months. CONCLUSION: The prevalence of periodontitis in young patients is ranges widely, which could indicate populational predispositions, underdiagnosing or lack of standardisation in diagnosis.

Diagnosis of aggressive periodontitis: A dilemma?

Periodontitis is one of the leading causes of tooth loss in the adult population. This disease can be classified into various categories, and one of the most destructive amongst them is aggressive periodontitis (AgP). The incidence of AgP is lower than other types of periodontitis. However, it affects young individuals and can cause severe destruction of tooth-supporting structures including tooth loss if left untreated. The current classification for diagnosing periodontal disease was established by the American Academy of Periodontology (AAP) in 1999. This classification provided strict guidelines to aid in AgP diagnosis. These include three main factors: systemically healthy individual, rapid loss of clinical attachment, and familial aggregation. In spite of these specific guidelines, AgP diagnosis is often missed clinically due to various reasons. There is still a vast variation in the diagnostic criteria for identifying AgP and not all practitioners utilize the AAP guidelines for their diagnosis. Furthermore, the definition of the disease might be changing in the future to better represent the current understanding of the disease. Since early diagnosis and prompt treatment is key in treating these patients, it is important to have calibration in the diagnosis process. This review aims to identify sources of variation and ambiguity in diagnosing AgP among dental practitioners. For this purpose, we have conducted an extensive literature search and outlined the various diagnostic aids for AgP patients reported in the literature. Understanding and correcting these variations can simplify the diagnostic process leading to faster treatment of patients affected with AgP. This review also emphasizes the importance of minimizing the bias in identifying patients with AgP and highlights the best tools for this purpose.

Treatment of Gummy Smile of Multifactorial Etiology: A Case Report.

INTRODUCTION: This case report describes the management of a patient diagnosed with excessive gingival display caused by altered passive eruption and hyperactive lip. Treatment for this patient was staged and included esthetic crown lengthening and a subsequent lip repositioning procedure. CASE PRESENTATION: A 17-year-old female was referred for assessment of a "gummy smile." The patient reported a history of mouth breathing and a sports injury causing a non-vital tooth #9, which had been temporarily restored. After periodontal evaluation, the patient was diagnosed with plaque-induced gingivitis and excessive gingival display due to hyperactive lip and altered passive eruption. After initial therapy, an esthetic crown lengthening procedure was performed on the maxillary anterior sextant, resulting in ideal maxillary anterior crown contours. Six weeks after esthetic crown lengthening, the patient was treated for hyperactive lip by a modified lip repositioning surgery. Subsequently, the patient received a permanent restoration on tooth #9. During the 1.5-year follow-up time the patient repeatedly expressed her satisfaction with the improvement of her smile. Persistent mouth breathing and associated recurrent gingival inflammation remained a challenge. CONCLUSIONS: The presented case illustrates results of sequentially applied techniques for management of a gummy smile of multifactorial etiology and limitations imposed by unresolved factors. Excessive gingival display can be a significant esthetic concern for patients. Understanding the etiology can be challenging due to multiple factors that may be concomitantly involved. Accurate diagnosis and treatment planning are critical for proper management. When multifactorial etiology is present, multiple treatment modalities, including various surgical approaches, are necessary to obtain positive outcomes in such patients.

Transgenic expression of Dspp partially rescued the long bone defects of Dmp1-null mice.

Dentin matrix protein 1 (DMP1) and dentin sialophosphoprotein (DSPP) belong to the Small Integrin-Binding Ligand N-linked Glycoprotein (SIBLING) family. In addition to the features common to all SIBLING members, DMP1 and DSPP share several unique similarities in chemical structure, proteolytic activation and tissue localization. Mutations in, or deletion of DMP1, cause autosomal recessive hypophosphatemic rickets along with dental defects; DSPP mutations or its ablation are associated with dentinogenesis imperfecta. While the roles and functional mechanisms of DMP1 in osteogenesis have been extensively studied, those of DSPP in long bones have been studied only to a limited extent. Previous studies by our group revealed that transgenic expression of Dspp completely rescued the dentin defects of Dmp1-null (Dmp1(-/-)) mice. In this investigation, we assessed the effects of transgenic Dspp on osteogenesis by analyzing the formation and mineralization of the long bones in Dmp1(-/-) mice that expresses a transgene encoding full-length DSPP driven by a 3.6-kb rat Col1a1 promoter (referred as "Dmp1(-/-);Dspp-Tg mice"). We characterized the long bones of the Dmp1(-/-);Dspp-Tg mice at different ages and compared them with those from Dmp1(-/-) and Dmp1(+/-) (normal control) mice. Our analyses showed that the long bones of Dmp1(-/-);Dspp-Tg mice had a significant increase in cortical bone thickness, bone volume and mineral density along with a remarkable restoration of trabecular thickness compared to those of the Dmp1(-/-) mice. The long bones of Dmp1(-/-);Dspp-Tg mice underwent a dramatic reduction in the amount of osteoid, significant improvement of the collagen fibrillar network, and better organization of the lacunocanalicular system, compared to the Dmp1(-/-) mice. The elevated levels of biglycan, bone sialoprotein and osteopontin in Dmp1(-/-) mice were also noticeably corrected by the transgenic expression of Dspp. These findings suggest that DSPP and DMP1 may function synergistically within the complex milieus of bone matrices.