Primary mandibular first molar with three roots: a case report

Knowledge of the size, morphology and variation of the root canals is required to achieve a successful endodontic treatment. Primary mandibular first molars usually have two roots. Three rooted primary mandibular first molar with the formation of accessory roots is uncommon. This paper reports a case of three-rooted primary mandibular first molar in a four year old male patient

prevalence of bruxism and correlated factors in children referred to dental schools of Tehran, based on parents' report

Bruxism is defined as the habitual nonfunctional forceful contact between occlusal tooth surfaces. The aim of this study was to determine the prevalence of bruxism and correlated factors in children referred to dental schools of Tehran, based on parents' report. This cross-sectional descriptive study was conducted on 600 4-12 year-old children with a mean age of 7.4 +/- 2.4 years, who were referred to four dental schools in Tehran. After collecting information with questionnaire filled out by parents, chi[2] Fisher Test, Mann-Whitney and t-Test were used to analyze the data. The prevalence of bruxism was 26.2%. Bruxism begun in average at the age of 4.9 +/- 2 years. Also it occurred 2.6 times more in children who had a family history of bruxism [father-mother], compared to children who didn't have such a history. 87% of children with bruxism had a history of distressing events in their life, and 13% of children with bruxism did not report any history of distressing events in their life. In this study most common oral habit was nail biting. In study of parasomnias, drooling was the most, and snoring the least reported sleep disorder. Bruxism in children with drooling was twice more than in other children. The prevalence of bruxism in children with temporomandibular disorder was 63.6% and in children without TMD was 24.7%. Based on parents' report, 26.2% of children showed bruxism and there was a significant relation between bruxism and mother's job, family history, distressing event in life, parasomnias, especially drooling and sleep walking, TMD, hyperactivity, depression, acrophobia and lygophobia

Considering the second primary molar as the sole clinical index of growth condition

Assessment of skeletal maturity is an integral part of interceptive diagnosis and treatment planning. The present method of skeletal maturity assessment like handwrist or cervical vertebrae radiographies are expensive,require elaborate equipment and account for high radiation exposure, especially for growing children. This study tried to consider the value of the 2nd primary molar in growth stage. 40 samples aged 8-13 were tested by their panoramic and handwrist radiographs. there was a coincidence between presence calcified sesamoid and 2nd primary molar as the last tooth. The result showed that it could be a reliable index to predict the growth stage in 1st visit without radiography