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A double-blind controlled trial initiated in 1944 has led to the common narrative that a 10-mg daily vitamin C intake is adequate to prevent and treat impaired wound healing, and by inference, other collagen-related diseases such as heart disease or stroke. The WHO relies on this narrative to set the recommended nutrient intake for vitamin C. This narrative, however, is based on what is known as the eyeball method of data assessment. The 1944 trial published individual participant data on scar strength providing an opportunity to statistically probe the validity of the 10-mg narrative, something which has not yet been done. The findings show that a vitamin C intake that averages to 10 mg/d over a mean follow-up of 11.5 mo was associated with a 42% weakened scar strength when compared with 80 mg vitamin C intake/d (P  < 0.001). The observed dose-response curve between scar strength and vitamin C intake suggests that the daily vitamin C intake needed to prevent collagen-related pathologies is in the range recommended by the National Academy of Medicine and the European Food Safety Authority (75 to 110 mg/d), not the WHO recommendation (45 mg/d). The findings also show that a vitamin C intake that averages to 65 mg/d over a mean follow-up of 6.5 mo failed to restore the normal wound-healing capacity of vitamin C–depleted tissues; such tissues had a 49% weaker scar strength when compared with nondepleted tissues (P  < 0.05). Thus, average daily vitamin C intakes ∼50% higher than the WHO recommends may fail to treat existing collagen-related pathologies. It is concluded that the prior lack of statistical analyses of a landmark trial may have led to a misleading narrative on the vitamin C needs for the prevention and treatment of collagen-related pathologies. [ABSTRACT FROM AUTHOR]

Introduction: Anterior open-bite (AOB) treatment is considered challenging because of difficulties in determining and addressing etiologic factors and the potential for relapse in the vertical dimension after treatment. In this review, we compiled evidence on the long-term stability of the major therapeutic interventions for correcting AOB. Our objective was to review and compile evidence for the stability of surgical and nonsurgical therapies for AOB malocclusion. Our data sources were PubMed, EMBASE, Cochrane Library, limited gray literature search, and hand searching. Methods: A search was performed of the electronic health literature on the stability of AOB after treatment. Hand searching of major orthodontic journals and limited gray literature searching was also performed, and all pertinent abstracts were reviewed for inclusion. Full articles were retrieved for abstracts or titles that met the initial inclusion criteria or lacked sufficient detail for immediate exclusion. Studies accepted for analysis were reviewed and their relevant data retrieved for pooling. The long-term stability estimates were pooled into nonsurgical and surgical groups, and summary statistics were generated. Results: One hundred five abstracts met the initial search criteria, and 21 articles were included in final analyses. Rejected articles failed to exhibit follow-up times of 12 months or more, did not include measurements of overbite (OB), or did not meet inclusion criteria. All included articles were divided into a surgical group (SX) with a mean age of 23.3 years and a nonsurgical group (NSX) with a mean age of 16.4 years. All studies were case series. Random-effects statistical models were used to pool the mean OB measures before and after treatment and also at the long-term follow-up. The pretreatment adjusted means of OB were –2.8 mm for the SX and –2.5 mm for the NSX. AOB closures up to +1.6 mm (SX) and +1.4 mm (NSX) were achieved. Relapse in the SX group during the mean 3.5 years of follow-up reduced the OB to +1.3 mm; the NSX group relapsed to +0.8 mm in the mean 3.2 years of follow-up. Pooled results indicated reasonable stability of both the SX (82%) and NSX (75%) treatments of AOB measured by positive OB at 12 or more months after the treatment interventions. Conclusions: In the included case series publications, success of both the SX and NSX treatments of AOB appeared to be greater than 75%. Because the SX and the NSX were examined in different studies and applied to different clinical populations, no direct assessment of comparative effectiveness was possible. The pooled results should be viewed with caution because of the lack of within-study control groups and the variability among studies. [Copyright &y& Elsevier]

Translating basic science evidence into clinical trials is particularly challenging. [Copyright &y& Elsevier]

Introduction: The high prevalence of orthodontic treatment in young people makes the associated radiation to the head and neck of potential public-health significance. In this study, we estimated secular changes (1963-2003) in age-specific organ doses associated with orthodontic care and collective organ doses in the United States in 1999. Methods: A survey of radiographic records at 1 university clinic was combined with published estimates to provide organ-specific radiation doses. Collective organ doses were estimated from the 1999 US Nationwide Evaluation of X-ray Trends and published orthodontic utilization surveys. Results: Before 1992, orthodontic care in a university setting was associated with mean doses of 7.0 milligrays (mGy) to the thyroid, 0.8 mGy to the red bone marrow, 2.7 mGy to the brain, 13.2 mGy to the salivary glands, and 5.1 mGy to the bone. After 1992, the doses decreased to 2.8 mGy to the thyroid, 0.3 mGy to the red bone marrow, 0.7 mGy to the brain, 6.2 mGy to the saliva glands, and 2.4 mGy to the bone. Around 1999, the collective doses associated with orthodontic care in the United States in patients less than 19 years of age were 400 Gy to the red bone marrow and 3800 Gy to the thyroid. Conclusions: Orthodontic care, in part due to its high prevalence, potentially contributes significantly to the diagnostic radiation burden in those less than 19 years old in the United States. [Copyright &y& Elsevier]

Introduction: The goals of this study were to describe secular trends in preadult orthodontic care for people in the United States born between 1942 and 1972, and to estimate the number of new preadult orthodontic treatment starts in 2006. Methods: Orthodontic care experience in this group was ascertained by 2 questions in the Third National Health and Nutrition Examination Survey (NHANES III). Results: Of those in the 1942 birth cohort, 4.6% (SE 1.5) and, of those in the 1972 birth cohort, 29.7% (SE 3.8) received preadult orthodontic care. These increasing secular trends were more pronounced for people of higher socioeconomic positions (P <.03) and girls (P = .04). If the orthodontic care prevalence continues to increase yearly by 0.7 percentage point (SE 0.08), there will be 1.62 million new preadult patient starts in 2006, an increase of 26,000 over 2005. Conclusions: The prevalence of preadult orthodontic care has steadily increased for successive birth cohorts between 1942 and 1972, particularly for girls and those at higher socioeconomic positions. Linear extrapolations extending to 2006 reasonably agree with survey data, suggesting linear growth in orthodontic treatment use by those born in the latter half of the 20th century. [Copyright &y& Elsevier]

PURPOSE: Periodontitis has been linked to the occurrence of various systemic diseases. The goal of this study was to explore the periodontitis–cancer association in the NHANES I Epidemiologic Follow-up Study.METHODS: Data were available on 11,328 adults, age 25 to 74 years, who were diagnosed as dentate individuals with either periodontitis (n = 2092), gingivitis (n = 2603), a healthy periodontium (n = 2,671), or as individuals without teeth (edentulous n = 3,962) at the beginning of the follow-up. The main outcome measure was fatal cancer, as ascertained from death certificates.RESULTS: Compared with individuals with a healthy periodontium, fatal cancer occurrence was positively associated with periodontitis at baseline (age and gender adjusted odds ratio = 1.55, 95% confidence interval: 1.25–1.92). Of the different cancer types, lung cancer demonstrated the strongest association. After adjustment for known risk factors for lung cancer, the magnitude of the association between periodontitis and lung cancer ranged between 1.48 (95% confidence interval: 0.88–2.50) and 1.73 (95% confidence interval: 1.01–2.97).CONCLUSIONS: Associations between periodontitis and lung cancer mortality can be identified above and beyond adjustment for known risk factors for lung cancer. Despite these apparent unconfounded associations, there are reasons to believe that the periodontitis-cancer associations may be spurious. [Copyright &y& Elsevier]

Relationship between periodontal disease and lung cancer: A systematic review and meta-analysis. Wang J, Yang X, Zou X, Zhang Y, Wang J, Wang Y. J Periodontal Res. 2020 Oct;55(5):581–593. doi: 10.1111/jre.12772. Epub 2020 Jun 25. PMID: 32,583,879. National Natural Science Foundation of China and Scientific Research foundation of the Health Planning Committee of Sichuan. Systematic review with meta-analysis of cohort and case-control studies. [ABSTRACT FROM AUTHOR]

Disasters surrounding medical drugs and devices that led to public outcries for regulation have led to both legislation and the recognition that all sources of evidence are not equal in terms of reliability. Randomized controlled trials provide more reliable evidence than case-series, and human studies provide more reliable evidence than animal studies. In evidence-based medicine, different hierarchies have been created to grade the reliability of evidence. This report provides a brief review of the evidence-pyramid. [Copyright &y& Elsevier]

Three different types of systematic experiments are powerful tools to evaluate whether the low-level evidence on cause and effect indeed translates into tangible outcomes in humans. The evidence pyramid forms the core of evidence-based dentistry that allows grading the evidence. [Copyright &y& Elsevier]

Article Title and Bibliographic Information: Miyamoto T, Kumagai T, Jones JA, Van Dyke TE, Nunn ME. Compliance as a prognostic indicator: retrospective study of 505 patients treated and maintained for 15 years. J Periodontol 2006;77(2):223-32. Level of Evidence: 3a Purpose/Question: To evaluate the impact of compliance with maintenance on tooth loss Source of Funding: Not reported Type of Study/Design: Cohort study [Copyright &y& Elsevier]

Introduction: Most of the published literature on the management of overbite with the Invisalign appliance (Align Technology, Santa Clara, Calif) consists of case reports and case series.Methods: In this retrospective study of 120 patients, we sought to assess the nature of overbite changes with the Invisalign appliance. Records were collected from 3 practitioners, all experienced with the Invisalign technique. The patients were consecutively treated adults (>18 years old) who underwent orthodontic treatment only with the Invisalign appliance. Patients with major transverse or anteroposterior changes or extraction treatment plans were excluded. The study sample included 68 patients with normal overbites, 40 with deepbites, and 12 with open bites. Their median age was 33 years, and 70% of the patients were women.Results: Cephalometric analyses indicated that the deepbite patients had a median overbite opening of 1.5 mm, whereas the open bite patients had a median deepening of 1.5 mm. The median change for the normal overbite patients was 0.3 mm. Changes in incisor position were responsible for most of the improvements in the deepbite and open bite groups. Minimal changes in molar vertical position and mandibular plane angle were noted.Conclusions: The Invisalign appliance appears to manage the vertical dimension relatively well, and the primary mechanism is via incisor movements. [ABSTRACT FROM AUTHOR]

Article Title and Bibliographic Information: Safety of oral bisphosphonates: controlled studies on alveolar bone Jeffcoat MK. Int J Oral Maxillofac Implants 2006 May-Jun;21(3):349-53 Level of Evidence: 4 Purpose/Question: To determine if oral bisphosphonates cause osteonecrosis of the jaw Source of Funding: Proctor and Gamble & Merck Research Type of Study/Design: 2 cohort studies [Copyright &y& Elsevier]

Original Article: Sedaghatfar M, August MA, Dodson TB. Panoramic radiographic findings as predictors of inferior alveolar nerve exposure following third molar extraction. J Oral Maxillofac Surg 2005;63(1):3-7. Level of Evidence: 3 Source of Funding: Not reported Type of Study/Design: Cross-sectional study [Copyright &y& Elsevier]

Original Article: Longstreth WT Jr, Phillips LE, Drangsholt M, Koepsell TD, Custer BS, Gehrels JA, et al. Dental x-rays and the risk of intracranial meningioma: a population-based case-control study. Cancer 2004;100(5):1026-34. Level of Evidence: 3a Purpose: The purpose of the study was to investigate whether dental radiography increases the risk for intra-cranial meningioma. Source of Funding: National Cancer Insitute Type of Study/Design: Population-based case-control study [Copyright &y& Elsevier]