Dentosphere : World of Dentistry

CLICK HERE FOR REGISTRATION TO MAIN CONFERENCE CLICK HERE TO REGISTER FOR PRECONFERENCE WORKSHOPS   Calling all orthodontists, residents, and dental pros! The 16th International Orthodontic Conference of ODOAN is landing in Dharan, Nepal on Nov 15, 2025 – your ultimate hub for cutting-edge insights, networking, and innovation in orthodontics! 🌟 Don't miss the exclusive Pre-Conference Workshops on Nov 14: Workshop 1: In-Office Aligners with Dr. Abhishek Gupta (Master digital smiles!) Workshop 2: Self-Ligation & TADs for Complex Malocclusions with Dr. Abhishek Ghosh (Tackle tough cases like a pro!) Early Bird rates extended till Oct 15 – register NOW and save big! PG residents: As low as NPR 7500 for main + NPR 2000 for both workshops. International? Just $90-100 USD entry! After October 15, $120 only. Join 100s of global experts, ignite your practice, and explore Nepal's vibes. Spots filling fast – secure yours today! BANK DETAILS FOR PAYMENT OF REGISTRATION FEES CLICK HERE...

The spontaneous production of an electric current resulting from two dissimilar metals in the oral cavity is called: A. Nuclear reaction B. Galvanic action C. Precipitation reaction D. Thermodynamics The correct answer is  B. Galvanic action Galvanic action, also known as oral galvanism, occurs when two dissimilar metals in the oral cavity contact saliva (an electrolyte), forming a battery-like setup that generates a spontaneous electric current. This can cause symptoms like metallic taste, pain, or tissue irritation. Studies and dental resources confirm this electrochemical process is specific to bimetallic interactions in the mouth, distinguishing it from unrelated options: nuclear reactions (subatomic), precipitation (ion formation), and thermodynamics (energy principles).

 # Which of the following materials has been shown to stimulate reparative dentine formation most effectively when applied to the pulpal wall of a very deep cavity? A. Copalite varnish B. Calcium hydroxide preparation C. Zinc phosphate cement D. Anhydrous glass ionomer cement The correct answer is  B. Calcium hydroxide preparation Calcium hydroxide has been established as the gold standard for stimulating reparative dentin formation in deep cavities near the pulp. It promotes odontoblast differentiation and dentin bridge formation by releasing calcium ions, which enhance fibronectin expression and mineralization. Studies, including clinical reviews, show success rates of around 83% for indirect pulp capping with calcium hydroxide. In comparison: A. Copalite varnish : Acts as a protective liner to reduce irritation but does not induce reparative dentin. C. Zinc phosphate cement : Provides thermal insulation as a base but lacks bioactive properties for dentin stimulation. ...

If you need to arrange / reschedule any appointment with Dr. Raman Dhungel,  BDS (BPKIHS), MDS Resident Department of Orthodontics, BPKIHS Dharan, then you can message on Whatsapp (+9779803027654) or call on +9779803027654/+9779849510059. Call only when absolutely necessary and preferably at 6:00 PM to 8:00 PM. 

Difference in the amount of space needed for the accommodation of the incisors and amount of space available for them is known as: A. Primate space B. Leeway Space of Nance C. Anthropoid space D. Incisal liability D. Incisal liability Incisal liability, also known as incisor liability, describes the space discrepancy in the mixed dentition phase where the permanent incisors require more mesiodistal width (typically 7 mm in the maxillary arch and 5 mm in the mandibular arch) than the primary incisors they replace, creating a potential crowding issue that must be accommodated by factors like interdental spacing, arch perimeter changes, or leeway space. This is distinct from primate space (A, developmental space distal to the lateral incisor), leeway space of Nance (B, difference between deciduous and permanent molars/canines), and anthropoid space (C, a less common term sometimes used interchangeably with primate space in non-human primates). 

Type of crowding that is genetically determined and is caused by disproportionately sized teeth and jaws: A. Primary crowding B. Secondary crowding C. Tertiary crowding D. Environmental crowding The correct answer is A. Primary crowding.  Primary crowding refers to a type of dental crowding caused by a genetic discrepancy in tooth and jaw sizes, such as larger teeth relative to the jaw, leading to misalignment. This contrasts with secondary crowding, which results from environmental factors like early tooth loss, and tertiary crowding, which involves late-stage incisor irregularities. Environmental crowding isn't a standard classification but aligns with secondary causes.

Which of the following is the least biocompatible? A. TMA B. Elgiloy C. Stainless steel D. Cu-NiTi The correct answer is B. Elgiloy. Elgiloy (a cobalt-chromium-nickel alloy) is the least biocompatible among the options due to its higher nickel content (14-16%) compared to stainless steel (8%), leading to greater nickel and chromium ion release in simulated oral environments. Studies show it induces significant neurotoxicity via necrosis, elevated oxidative stress, and higher cytotoxicity (2.7-fold increase in dead cells) relative to stainless steel (apoptosis, 1.7-fold dead cells), TMA (variable but generally low ion release and non-toxic), and Cu-NiTi (lower ion release and minimal cytotoxicity). This increases risks of allergic reactions and tissue irritation in orthodontic use.

 # What is facial divergence? A. Relation of maxilla to mandible B. Lower face inclination in relation to the forehead C. Relation of mandible to forehead D. Relation of lower face with cranial base The correct answer is B. Lower face inclination in relation to the forehead Examination of facial divergence is done by viewing the patient from the side. Facial divergence is often influenced by patient’s ethnicity and racial background. For instance, convex profile with an anterior facial divergence is a normal feature of negroid race groups. Facial divergence is defined as an anterior or posterior inclination of mandible (lower face) relative to the forehead. Assessment of facial divergence is done by a line drawn from the forehead to the chin. Facial divergence of an individual may fall into any one of the following three types: 1. Straight/orthognathic—A line drawn from forehead to chin is almost straight. 2. Anterior facial divergence—The line drawn from forehead to the chin is ...

 # Which radiographic landmark extends inferiorly from the medial pterygoid plate? A. Nasolabial fold B. Hamular process C. Zygomatic process D. Maxillary tuberosity The correct answer is B. Hamular process. The radiographic landmark that extends inferiorly from the medial pterygoid plate is the hamulus (or hamular process) of the sphenoid bone. The hamular process is a small, hook-like projection that extends downward from the medial pterygoid plate. It is visible on certain radiographic views, such as panoramic or lateral cephalometric radiographs, and serves as an attachment point for structures like the pterygomandibular raphe and the tensor veli palatini muscle.

# A 12 year old patient presents with premature loss of primary teeth. On radiographic examination, a sharply marginated lucency is seen in the area of tooth loss. A biopsy specimen shows a round cell infiltrate with numerous eosinophils. Which of the following diagnosis is suggested? A. Cherubism B. Gardener’s syndrome C. Fibrous dysplasia D. Langerhans’ cell disease The correct answer is D. Langerhans’ cell disease . Explanation: The clinical presentation of a 12-year-old patient with premature loss of primary teeth, a sharply marginated radiolucency on radiographic examination, and a biopsy showing a round cell infiltrate with numerous eosinophils strongly suggests Langerhans’ cell disease (also known as Langerhans cell histiocytosis, LCH). LCH is a rare disorder characterized by the proliferation of Langerhans cells, often affecting children. In the oral cavity, it commonly presents with premature tooth loss, "floating teeth" due to bone destruction, and sharply defin...

 # Dental fluorosis, a tooth defect, is categorized as one of the following: A. Hypoplasia B. Aplasia C. Hyperplasia D. Heteroplasia The correct answer is A. Hypoplasia . Dental fluorosis is a developmental defect of tooth enamel caused by excessive fluoride intake during tooth formation, leading to hypomineralization and hypoplasia of the enamel. It results in incomplete or defective enamel formation, often presenting as white spots, mottling, or pitting. Explanation of other options: B. Aplasia : This refers to the absence or complete failure of development of a tissue or organ, which does not apply to dental fluorosis, as the enamel is present but defective. C. Hyperplasia : This indicates an excessive growth or overdevelopment of tissue, which is not characteristic of fluorosis, where the issue is underdevelopment or defective enamel. D. Heteroplasia : This term is not commonly used in dental contexts and generally refers to the formation of abnormal tissue in an inapprop...

 # Which of the following cells are responsible for acute suppurative inflammation? A. Plasma cells B. Macrophages C. Neutrophils D. Lymphocytes The correct answer is C. Neutrophils. Neutrophils are the primary cells responsible for acute suppurative inflammation, which is characterized by the rapid accumulation of pus (consisting of neutrophils, dead cells, and tissue debris) in response to infection or tissue injury. They are the first responders in acute inflammatory processes, particularly in bacterial infections, and are key in forming abscesses and other suppurative (pus-forming) conditions. Explanation of other options: A. Plasma cells: These are involved in humoral immunity, producing antibodies, and are more associated with chronic inflammation or immune responses, not acute suppurative inflammation. B. Macrophages: These play a role in both acute and chronic inflammation but are more prominent in chronic inflammation and tissue repair, not specifically in suppurative (pus...

1. In orthodontic biomechanics, a low moment-to-force ratio typically results in which type of tooth movement? A. Bodily movement B. Controlled tipping C. Uncontrolled tipping D. Intrusion E. Extrusion 2. The center of resistance of a single-rooted tooth is located approximately at what distance from the alveolar crest? A. One-third of the root length B. One-half of the root length C. Two-thirds of the root length D. At the apex E. At the cervical margin

  The Hidden Environmental Cost of Face Masks: How Disposable Masks Contribute to Microplastic Pollution In the wake of the COVID-19 pandemic, disposable face masks became our everyday armor against an invisible enemy. Billions were produced, worn, and discarded, saving countless lives but leaving a lingering question: What happens to all that waste? A recent study published in Environmental Pollution (2024) by researchers Anna A. Bogush and Ivan Kourtchev from Coventry University sheds light on a troubling side effect—disposable masks as a sneaky source of microplastics and harmful chemicals leaching into our environment. If you're concerned about plastic pollution, ocean health, or the long-term legacy of the pandemic, this is a must-read. Let's dive into the findings and explore what it means for our planet. The Pandemic's Plastic Boom: A Quick Recap Remember 2020? As the world grappled with COVID-19, face masks went from niche medical gear to global essentials. The ...

# An orthodontist is using a bracket with a 0.022-inch slot. Which of the following is the most significant disadvantage of using a wire that is not fully seated in this slot? A. Inability to express the full programmed torque and angulation. B. Increased friction between the wire and the bracket. C. Higher risk of bracket debonding. D. Reduced anchorage control. # A patient presents with a history of nickel allergy. What type of orthodontic bracket would be the most appropriate choice to avoid an allergic reaction? A. Stainless steel brackets. B. Ceramic brackets. C. Nickel-titanium brackets. D. Gold-plated brackets. # What is the primary advantage of a self-ligating bracket system compared to a conventional bracket system with elastomeric ligatures? A. Increased control over individual tooth rotation. B. Improved oral hygiene due to less plaque accumulation. C. Reduced treatment time due to increased friction. ...

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 This is a compilation of all the thesis topics done at B.P. Koirala Institute of Health Sciences, Dharan, Nepal, by postgraduate residents in the Department of Orthodontics and Dentofacial Orthopedics. 1. ORIENTATION AND POSITION OF HYOID BONE IN ORTHODONTIC PATIENTS WITH DIFFERENT DENTOFACIAL GROWTH PATTERNS REPORTING TO CODS, BPKIHS: Dr. Bhushan Bhattarai, July 2014 2. THE SHAPE, SIZE, AND BRIDGING OF THE SELLA TURCICA IN SKELETAL CLASS I, II & III ADULT ORTHODONTIC PATIENTS, REPORTING TO CODS, BPKIHS: Dr. Gunjan Kumar Shrestha, July 2014 3. PHARYNGEAL WIDTHS COMPARISON IN DIFFERENT SKELETAL MALOCCLUSIONS AND GROWTH PATTERNS OF PATIENTS VISITING DEPARTMENT OF ORTHODONTICS, BPKIHS: Dr. Nabin Kumar Chaudhary, December 2020 4. CORRELATION BETWEEN DENTAL ARCH WIDTH AND VERTICAL FACIAL MORPHOLOGY IN PATIENTS SEEKING ORTHODONTIC TREATMENT IN BPKIHS, DHARAN, NEPAL: Dr. Subash Shrestha, May 2023 5. NEPALESE TRANSLATION AND VALIDATION OF THE ORAL AESTHETIC SUBJECTIVE IMPACT SCORE (OA...

 These are some very useful thesis topics that are practically useful and doable by postgraduate students. ## 1. Cephalometric and Radiographic Studies cephalometric analysis in orthodontic treatment planning These studies utilize 2D radiographs (Lateral Cephalograms and OPGs) which are widely available. Cephalometric Norms for a Specific Nepalese Ethnic Group: Establish Steiner's or Tweed's cephalometric norms for a specific population (e.g., Newar, Rai, Gurung) to create a local database. Practical Application: Provides more accurate diagnostic standards for local populations instead of relying solely on Caucasian norms. Soft Tissue Profile Changes after First Premolar Extractions: A retrospective study evaluating changes in the lips and chin position in Class I bimaxillary protrusion cases. Practical Application: Helps in predicting esthetic outcomes and managing patient expectations regarding facial changes.

I. Introduction to Advanced Dental Training This report provides a comprehensive overview of advanced educational pathways within the medical and dental fields, specifically distinguishing between fellowships and clerkships. The primary aim is to offer detailed guidance for orthodontists holding a Master of Dental Surgery (MDS) degree who seek to pursue further specialization in cleft lip and palate orthodontics. The information presented herein is designed to equip dental professionals with the knowledge necessary to make informed decisions regarding their advanced training and career trajectory. Your specific interest in cleft lip and palate orthodontics underscores a desire for highly specialized, multidisciplinary training that extends beyond a general orthodontic residency. This report will address the unique requirements, opportunities, and challenges inherent in this niche field, providing a structured pathway for aspiring specialists. II. Understanding Fellowships in Medical an...

# Which of the following terms describes an increase in the number of cells? A. Hypertrophy B. Maturation C. Accretion D. Hyperplasia # The concept that growth occurs along an axis from head to tail is known as which growth pattern? A. Anteroposterior B. Proximodistal C. Somatic D. Cephalocaudal # According to Scammons' curves, which tissue system exhibits the most rapid growth during the first few years of life, followed by a plateau? A. Genital system B. General body growth C. Lymphoid system D. Neural system # Which theory of craniofacial growth posits that growth occurs primarily due to adaptive responses of the skeletal tissues to functional demands of surrounding soft tissues and spaces? A. Sutural theory B. Servosystem theory C. Cartilage theory D. Functional Matrix Theory # The primary mechanism for the increase in size of the cranial vault after birth is: A. Su...

# Which of the following cephalometric parameters suggest skeletal class III malocclusion? 1. ANB is less than 0 degree 2. SNA= 84 degrees 3. SNB=82 degrees 4. Wit’s appraisal shows point A before point B 5. FMA is 40 degrees A. 2, 4 and 5 B. 1, 4 and 5 C. 3, 4 and 5 D. 1 and 3 # A patient presents with anterior crowding as a result of large size of teeth in comparison to the base of mandible. This will be classified as: A. Tertiary crowding B. Secondary crowding C. Third degree crowding D. Primary crowding # Which of the following cephalometric angles is primarily used to assess the anteroposterior position of the maxilla relative to the cranial base? A. FMA B. SNB C. ANB D. SNA # A patient with a skeletal Class II malocclusion typically exhibits which of the following characteristics? A. Prognathic mandible B. ANB angle greater than 4° C. Retrognathic maxilla D. Point B anterior to Point...

 # Which of the following cephalometric parameters suggest skeletal class III malocclusion? 1. ANB is less than 0 degree 2. SNA= 84 degrees 3. SNB=82 degrees 4. Wit’s appraisal shows point A before point B 5. FMA is 40 degrees (INICET 2025) A. 1, 4 and 5 B. 1 and 3 C. 2, 4 and 5 D. 3, 4 and 5 The correct answer is B. 1 and 3.  Explanation: 1. ANB is less than 0  degrees:  A negative ANB angle indicates that point B (mandible) is anterior to point A (maxilla), which is a classic sign of skeletal Class III malocclusion. 3. SNB= 82  d e g rees : While the average SNB is around 80 degrees, an SNB of 82 degrees indicates a more protrusive mandible relative to the cranial base, which is consistent with a Class III tendency (especially if SNA is normal or reduced). In contrast, SNA= 84  d e g rees (option 2) suggests a protrusive maxilla, which is typically seen in Class II, not Class III. 4. Wit’s appraisal shows point A before point B : This indicates...

 # A patient presents with anterior crowding as a result of large size of teeth in comparison to the base of mandible. This will be classified as: (AIIMS PG 2020) A. Primary Crowding B. Secondary Crowding C. Tertiary crowding D. Third degree crowding The correct answer is A. Primary Crowding. Explanation: Primary Crowding refers to crowding that arises due to a disproportion between the size of the teeth and the size of the jawbones. In this case, the patient has large teeth relative to a smaller mandible, leading to anterior crowding. This is often genetic in origin and present even before all permanent teeth have erupted. Secondary Crowding typically develops later, often due to factors like premature loss of primary teeth, leading to mesial migration of posterior teeth and a reduction in arch length for the erupting permanent teeth. Tertiary Crowding (also known as late adult crowding) usually occurs in late adolescence or early adulthood, often involving the lower anterior teet...

 # Anterior inclined plane (Catlan’s appliance) cannot be used in the following cases EXCEPT: A. Posterior open bite B. Class I with anterior flaring C. Severe class III with reverse overjet D. Anterior open bite The correct answer is A. Posterior open bite. The Catlan's appliance's mechanism of action involves disoccluding the posterior teeth, which is functionally similar to a posterior open bite. Therefore, an existing posterior open bite does not inherently prevent the appliance from being used to correct a co-existing anterior crossbite. The most common contraindications for Catlan's appliance are: Existing anterior open bite Periodontally compromised mandibular anterior teeth Cases where further proclination of maxillary anterior teeth is undesirable (e.g., severe anterior flaring if the goal is to reduce it). Severe skeletal discrepancies. Comparing the options: A. Posterior open bite: Not a direct contraindication for using Catlan's, but Catlan's doesn'...