No meta-analyses or systematic reviews have been conducted to evaluate numerous potential biasing factors contributing to the controversial results on congenitally missing teeth (CMT). We aimed to perform a rather comprehensive meta-analysis and systematic review on this subject. A thorough search was performed during September 2012 until April 2013 to find the available literature regarding CMT prevalence. Besides qualitatively discussing the literature, the meta-sample homogeneity, publication bias, and the effects of sample type, sample size, minimum and maximum ages of included subjects, gender imbalances, and scientific credit of the publishing journals on the reported CMT prevalence were statistically analyzed using Q-test, Egger regression, Spearman coefficient, Kruskal-Wallis, Welch t test (α = 0.05), and Mann-Whitney U test (α = 0.016, α = 0.007). A total of 111 reports were collected. Metadata were heterogeneous (P = 0.000). There was not a significant publication bias (Egger Regression P = 0.073). Prevalence rates differed in different types of populations (Kruskal-Wallis P = 0.001). Studies on orthodontic patients might report slightly (about 1%) higher prevalence (P = 0.009, corrected α = 0.016). Non-orthodontic dental patients showed a significant 2% decline [P = 0.007 (Mann-Whitney U)]. Enrolling more males in researches might significantly reduce the observed prevalence (Spearman ρ = -0.407, P = 0.001). Studies with higher minimums of subjects' age showed always slightly less CMT prevalence. This reached about -1.6% around the ages 10 to 13 and was significant for ages 10 to 12 (Welch t test P < 0.05). There seems to be no limit over the maximum age (Welch t test P > 0.2). Studies' sample sizes were correlated negatively with CMT prevalence (ρ = -0.250, P = 0.009). It was not verified whether higher CMT rates have better chances of being published (ρ = 0.132, P = 0.177). CMT definition should be unified. Samples should be sex-balanced. Enrolling both orthodontic and dental patients in similar proportions might be preferable over sampling from each of those groups. Sampling from children over 12 years seems advantageous. Two or more observers should examine larger samples to reduce the false negative error tied with such samples.

Background and objective: Diode lasers are becoming popular in gingival treatment following orthodontic treatments. Despite their merit and clinical implications, postoperative pain and bleeding after surgery with diode lasers are not assessed except in few controversial studies.Method: This controlled clinical trial was conducted on 30 healthy orthodontic patients aged 17–29 years, needing esthetic-only gingivectomy in the anterior maxilla. The patients were randomly divided into two groups of 15 each: experimental (laser-assisted surgery) and control (traditional surgery using scalpels). The bleeding rate following the surgery was assessed using the bleeding criteria established by the World Health Organization. The postsurgical pain level was recorded using visual analog scales immediately after the surgery and in patients who consumed analgesics, also 2 h after the analgesic consumption. The data were analyzed using the independent-samplest, Mann-Whitney U, and chi-square tests (α = 0.05).Results: The average bleeding rates were 1.15 and 0.36 in the conventional and laser groups, respectively (Mann-Whitney UP < 0.05). Experimental patients had no postsurgical pain (VAS1 and VAS2 = 0). In the control group, the average VAS1 pain was 5.2 out of 10. The difference between VAS1 values in the control/experimental groups was significant (Mann-Whitney UP < 0.001).Conclusion: 940-nm diode laser seems promising in reducing postoperative bleeding and pain of patients needing cosmetic smile lift surgeries.

As the most common complication of orthodontic treatment, pain can negatively impact quality of life and cause patients to discontinue treatment. However, few studies have evaluated pain during orthodontic treatment, with controversial findings. This study assessed the intensity and duration of pain and discomfort caused by active orthodontic treatment. This descriptive cross-sectional study examined 67 patients (22 men, 45 females; age range: 18-32 years) undergoing fixed orthodontic treatment. Patients were interviewed after the active treatment stage to assess their perceived pain and discomfort at different sites during different activities by a visual analogue scale. Frequency and duration of pain in different areas were analyzed by the chi-squared and chi-squared goodness-of-fit tests (α = 0.05). Among the 67 patients, 65.7% experienced general dentogingival pain or discomfort and 34.3% had localized dentogingival pain or discomfort (p = 0.010, chi-squared goodness-of-fit test). Masticating soft foods reduced discomfort (p = 0.000, chi-squared) in the tongue, cheeks, and in or around the teeth and gingivae. Pain and discomfort were mostly moderate while masticating sticky, fibrous, and firm foods. Mild pains were mostly reported during tooth brushing and while consuming soft foods (p < 0.05, chi-squared). Pain and discomfort tended to last for more than 4 weeks, except in the tongue, where pain and discomfort lasted less than 4 weeks (p < 0.05, chi-squared goodness-of-fit test). Pain and discomfort occur for more than 4 weeks after beginning fixed orthodontic treatment. Changing diets to incorporate softer foods is recommended to alleviate pain.