Dentosphere : World of Dentistry

  Temporary Anchorage Devices in Orthodontics: A Patient’s Guide If you’re undergoing orthodontic treatment, you may have heard your orthodontist mention Temporary Anchorage Devices (TADs) . These small, innovative tools have revolutionized modern orthodontics, offering precise and efficient solutions for complex tooth movements. This article explains what TADs are, how they work, their benefits, and what you can expect if they’re part of your treatment plan. What Are Temporary Anchorage Devices (TADs)? Temporary Anchorage Devices, or TADs, are small, screw-like devices made of biocompatible materials, such as titanium, that are temporarily placed in the jawbone to assist with orthodontic treatment. Think of them as stable anchors that provide a fixed point for moving teeth in ways that traditional braces or aligners alone might not achieve. TADs are typically 6–12 mm long and about 1–2 mm in diameter, similar in size to a small earring post. They’re placed in specific areas of...

 CLICK ON THIS LINK TO DOWNLOAD THE PDF FILE OF NEPAL'S NATIONAL ORAL HEALTH POLICY 2070 DOCUMENT  DOWNLOAD THE PDF FILE 

 # Which anti tubercular drug crosses the blood brain barrier (BBB)? A. INH B. Rifampicin C. Ethambutol D. Streptomycin The correct answer is A. INH (Isoniazid). Explanation: INH (Isoniazid):  - Crosses the blood-brain barrier (BBB) effectively, even in the absence of inflammation.  - First-line drug for tuberculous meningitis due to excellent CSF penetration. - Critical for treating CNS tuberculosis. Other Options: B. Rifampicin: Penetrates the BBB only when meninges are inflamed (e.g., in active meningitis). Not as reliable as INH under normal conditions. C. Ethambutol and D. Streptomycin: Poor BBB penetration, making them unsuitable for CNS tuberculosis. Key Takeaway: INH is the most reliable anti-tubercular drug for crossing the BBB, especially in latent or early CNS infections. Rifampicin’s efficacy depends on meningeal inflammation.

 # Which of the following can be diagnosed using dark field microscopy? A. Spirochaetes B. Streptococci C. Corynebacteria D. Mycobacteria The correct answer is A. Spirochaetes. Explanation: Dark field microscopy is particularly useful for observing organisms that are difficult to stain, such as Spirochaetes (e.g., Treponema pallidum, the causative agent of syphilis). These bacteria are thin and motile, making dark field microscopy ideal for visualizing their morphology and movement. Streptococci (B), Corynebacteria (C), and Mycobacteria (D) are typically diagnosed using Gram staining, Albert staining, or acid-fast staining, respectively. They do not require dark field microscopy.

 These are some samples of Lateral cephalograms you can use to study and do analyses. 

 # A two-month-old boy is referred for evaluation because he has an abnormal head shape. Physical examination shows low-set ears, and short-webbed fingers. A CT scan shows sagittal and lambdoid synostosis. Which of the following genes is most likely to cause this syndrome ? A. TWIST1 B. FGFR1 C. FGFR2 D. RAB23 The correct answer C. FGFR2. The most likely gene to cause the syndrome described, characterized by sagittal and lambdoid synostosis, low-set ears, and short-webbed fingers in a two-month-old boy, is C. FGFR2. Explanation: The clinical presentation suggests a craniosynostosis syndrome, with sagittal and lambdoid synostosis indicating premature fusion of cranial sutures, and additional features like low-set ears and short-webbed fingers (syndactyly) pointing toward a syndromic form. Among the options, mutations in FGFR2 (Fibroblast Growth Factor Receptor 2) are strongly associated with syndromic craniosynostoses, particularly Apert syndrome and Crouzon syndrome, both of which ...

 # Which of the following antibiotics acts by inhibiting cell wall synthesis? a) Doxycycline b) Aminoglycosides c) Erythromycin d) Cefepime The correct answer is D. Cefepime. The correct answer is d) Cefepime. Explanation: Cefepime is a fourth-generation cephalosporin antibiotic that inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs), disrupting peptidoglycan cross-linking, and leading to cell lysis. Doxycycline (a tetracycline) inhibits protein synthesis by binding to the 30s ribosomal subunit, preventing tRNA attachment. Aminoglycosides (e.g., gentamicin) also target protein synthesis by binding to the 30s ribosomal subunit, causing misreading of mRNA. Erythromycin (a macrolide) inhibits protein synthesis by binding to the 50s ribosomal subunit, blocking peptide chain elongation. Thus, only Cefepime acts by inhibiting cell wall synthesis.