Dental Identification — MCQs
Age estimation from teeth can be done by all the following methods, except:
The most reliable criterion in Gustafson's criteria is:
Best site for DNA extraction from a 2-month-old decomposed body?
Which traditional method is considered most reliable for personal identification in forensic science?
Pell and Gregory classification includes all of the following except:
Which of the following devices does not use the principle of fluorescence in the diagnosis of caries?
Height of contour of a tooth is determined by.
Which of the following tests is not used to assess the biocompatibility of dental materials?
During a postmortem examination of a young adult found with a faded tattoo, relatives mentioned that the tattoo was once visible. What is the best method to identify the tattoo?
Which of the following is NOT a post-mortem finding in carbon monoxide poisoning?
Dental Identification Indian Medical PG Practice Questions and MCQs
Question 1: Age estimation from teeth can be done by all the following methods, except:
- A. Boyde's method
- B. Miles' method
- C. Frame's method (Correct Answer)
- D. Gustafson's method
Explanation: ***Frame's method*** - **Frame's method** is not a recognized technique for **age estimation from teeth**. It is commonly described in the context of forensic anthropology concerning **bone analysis**. - While other methods listed explicitly use dental parameters, Frame's method is unrelated to direct **dental maturity** or **wear analysis**. *Boyde's method* - **Boyde's method** involves analyzing **incremental lines in enamel** or cementum, which are indicators of rhythmic growth and can be used for age determination. - This method focuses on the **microscopic structure** of tooth tissues to estimate age, a common approach in forensic odontology. *Miles' method* - **Miles' method** assesses age based on the degree of **attrition or tooth wear** observed on a molar's occlusal surface. - It is particularly useful for **age estimation in skeletal remains** where other dental indicators might be limited or absent. *Gustafson's method* - **Gustafson's method** is a comprehensive approach that considers six parameters of dental change: **attrition**, **secondary dentin deposition**, **periodontosis**, **cementum apposition**, **root resorption**, and **transparency of root dentin**. - These parameters are assigned scores, summed, and then correlated with age, making it a widely used and reliable method for **forensic age estimation**.
Question 2: The most reliable criterion in Gustafson's criteria is:
- A. Attrition
- B. Root resorption
- C. Transparency of root (Correct Answer)
- D. Periodontosis
Explanation: ***Transparency of root*** - This criterion, specifically **dentinal translucency**, is considered the most reliable age indicator in **Gustafson's criteria** due to its continuous and predictable increase with age. - The **translucency** results from the deposition of **secondary dentin** and obliteration of dentinal tubules, progressing from the apex towards the crown. *Attrition* - **Attrition** refers to the wear of tooth surfaces, which is highly variable and depends on diet, habits, and dental health, making it an unreliable age indicator. - While it generally increases with age, its rate is subject to many confounding factors. *Root resorption* - **Root resorption** is the progressive loss of tooth structure from the root and can be caused by various factors like trauma, infection, or orthodontic treatment, not solely age. - It is an unpredictable process and not a consistent age-related change. *Periodontosis* - **Periodontosis**, or **periodontal disease**, is inflammation and infection of the supporting structures around the teeth, influenced by oral hygiene and genetics. - While its prevalence may increase with age, it's not a direct and reliable physiological age marker for individuals.
Question 3: Best site for DNA extraction from a 2-month-old decomposed body?
- A. Muscle
- B. Bone
- C. Teeth (Correct Answer)
- D. Hair
Explanation: ***Teeth*** - Teeth, particularly the **pulp and dentin**, provide a highly protected environment for DNA, making them ideal for DNA extraction from **decomposed remains** due to their robust structure. - The hard enamel casing shields the internal DNA from environmental degradation and microbial contamination, allowing for excellent preservation over extended periods. - **Dental pulp** is consistently reliable and easily accessible, making teeth the **preferred first choice** in forensic DNA extraction from decomposed bodies. *Bone* - **Bone**, particularly the **petrous portion of the temporal bone** and long bones, is also an **excellent source** of DNA in decomposed remains and is widely used in forensic practice. - However, DNA extraction from bone requires more extensive processing (demineralization, grinding) compared to teeth, making it a **second-line choice** when teeth are available. - The petrous temporal bone is notably resistant to degradation, but teeth remain more practically accessible. *Muscle* - **Muscle tissue** contains significant DNA when fresh, but is highly susceptible to **autolysis and bacterial degradation** in a decomposed body. - As decomposition progresses over 2 months, muscle tissue breaks down rapidly, reducing both the quantity and quality of recoverable DNA significantly. *Hair* - **Hair shafts** primarily contain mitochondrial DNA (mtDNA) with minimal nuclear DNA, which limits their use for individual identification. - Hair roots (if present) contain nuclear DNA, but in decomposed remains, hair is often shed or degraded, making it an unreliable source compared to teeth.
Question 4: Which traditional method is considered most reliable for personal identification in forensic science?
- A. Gustafson's method
- B. Anthropometry
- C. DNA profiling
- D. Galton method (Correct Answer)
Explanation: ***Galton method*** - The **Galton method**, which refers to **fingerprint analysis**, is considered a highly reliable traditional method for personal identification due to the uniqueness and permanence of fingerprints. - No two individuals, even identical twins, have been found to have the exact same **fingerprint patterns**, making it a robust identifier. *Gustafson's method* - **Gustafson's method** is a technique used for **age estimation based on dental changes**, not for definitive personal identification. - While it provides an estimate of age, it cannot uniquely identify an individual. *DNA profiling* - **DNA profiling** is indeed the most reliable method for personal identification in modern forensic science, but it is not considered a "traditional" method. - The question specifically asks for a **traditional method**, distinguishing it from newer genetic techniques. *Anthropometry* - **Anthropometry** involves the measurement of the **human body and its parts**, often used for classification or to establish demographic profiles. - It is not reliable for unique personal identification as many individuals share similar physical measurements.
Question 5: Pell and Gregory classification includes all of the following except:
- A. Angulation of 3rd molar.
- B. Height of mandible.
- C. Relationship to adjacent teeth.
- D. Root size. (Correct Answer)
Explanation: ***Root size*** - The Pell and Gregory classification for impacted mandibular third molars assesses the **spatial relationship** between the impacted tooth and surrounding structures - It specifically evaluates: (1) **Class I-III** based on the relationship to the ramus and second molar, and (2) **Position A-C** based on depth relative to the occlusal plane - **Root size and morphology** are NOT parameters in this classification system, making this the correct answer *Angulation of 3rd molar* - While angulation is important in surgical planning, it is classified by **Winter's classification** (mesioangular, distoangular, vertical, horizontal), not by Pell and Gregory - However, Pell and Gregory does assess the **position** of the tooth, which is different from its angulation *Height of mandible* - The Pell and Gregory classification indirectly relates to mandibular dimensions through its assessment of available **anteroposterior space** - **Class I:** Sufficient space between distal of 2nd molar and anterior border of ramus - **Class II:** Space is less than the mesiodistal width of the 3rd molar crown - **Class III:** 3rd molar is completely within the ramus *Relationship to adjacent teeth* - The Pell and Gregory classification specifically includes the **spatial relationship** of the impacted 3rd molar to the 2nd molar and the ascending ramus - This relationship to adjacent structures is a fundamental component of the classification
Question 6: Which of the following devices does not use the principle of fluorescence in the diagnosis of caries?
- A. Diagnodent
- B. QLF
- C. FOTI (Correct Answer)
- D. Soprolife
Explanation: ***FOTI*** - **Fiber optic transillumination (FOTI)** detects caries by illuminating the tooth with a high-intensity light source and observing changes in light transmission, which do not involve fluorescence. - Caries lesions appear as **dark shadows** or translucency changes because demineralized enamel scatters light differently than healthy enamel. *Diagnodent* - The **Diagnodent** device uses a 655 nm laser diode to excite porphyrins produced by cariogenic bacteria within the tooth structure. - These porphyrins emit **fluorescence**, which is then detected by the device to quantify the extent of demineralization. *QLF* - **Quantitative Light-induced Fluorescence (QLF)** uses a specific wavelength of light to excite natural fluorophores in healthy enamel. - Demineralized areas associated with caries show a **loss of autofluorescence** or increased red fluorescence from bacterial byproducts, which is then quantified. *Soprolife* - **Soprolife** is an intraoral camera system that utilizes light-induced fluorescence to detect caries. - It uses specific wavelengths to highlight healthy tissue fluorescence in green and carious lesions with a **red or orange fluorescence**, indicating bacterial presence.
Question 7: Height of contour of a tooth is determined by.
- A. Non-undercut area of the tooth
- B. Undercut area of the tooth
- C. Survey line (Correct Answer)
- D. None of the options
Explanation: **Survey line** - The **height of contour** on a tooth is identified by the **survey line**, which represents the greatest circumference at a specific horizontal plane. - This line is crucial in removable prosthodontics for determining the most prominent part of the tooth, which dictates the path of insertion and removal of a prosthesis. *Non-undercut area of the tooth* - The non-undercut area is located **occlusal to the height of contour** and is not directly responsible for defining the height of contour itself. - This area is typically used for rigid clasp arms, as it does not allow for **flexibility** in prosthesis placement. *Undercut area of the tooth* - The undercut area is located **gingival to the height of contour** and is characterized by a decrease in tooth circumference. - While essential for **retention** in prosthodontics, it is the area *below* the height of contour, not the height of contour itself. *None of the options* - This option is incorrect because the **survey line** accurately defines the height of contour of a tooth.
Question 8: Which of the following tests is not used to assess the biocompatibility of dental materials?
- A. Implantation test
- B. Sensitization test
- C. Ames test (Correct Answer)
- D. Buehler test
Explanation: ***Ames test*** - This test is a **mutagenicity assay** that assesses the ability of a chemical to cause mutations in DNA, primarily used to identify potential **carcinogens**. - While related to safety, it does not directly evaluate the **biocompatibility** (tissue response and interaction) of a material in a biological system. *Buehler test* - The Buehler test is a common method for assessing **sensitization potential** of a material, often used to evaluate whether a material causes an allergic contact dermatitis. - This is a direct measure of an adverse biological response and thus contributes to the overall assessment of **biocompatibility**. *Implantation test* - This test involves placing the material directly into an animal tissue (e.g., muscle, subcutaneous tissue) to evaluate the **local tissue response** over time. - It assesses aspects like **inflammation**, encapsulation, and tissue integration, which are primary indicators of a material's **biocompatibility**. *Sensitization test* - These tests, like the Buehler test mentioned, aim to identify if a material can induce an **allergic reaction** in a host. - Detecting such immune responses is crucial for determining if a material is safe for long-term contact with biological tissues, making it an essential part of **biocompatibility assessment**.
Question 9: During a postmortem examination of a young adult found with a faded tattoo, relatives mentioned that the tattoo was once visible. What is the best method to identify the tattoo?
- A. Use a spectrophotometer for analysis
- B. Illuminate with ordinary light
- C. Perform an X-ray examination
- D. Illuminate with ultraviolet (UV) light (Correct Answer)
Explanation: ***Illuminate with ultraviolet (UV) light*** - **UV light** causes residual tattoo pigments, even faded ones, to **fluoresce**, making them visible again for identification. - This method is particularly effective for **older or faded tattoos** where the pigment has degraded or spread. *Use a spectrophotometer for analysis* - A spectrophotometer is used to measure the **intensity of light** as a function of wavelength, which is useful for **analyzing chemical components or color intensity**. - While it can analyze pigments, it is not the primary or most practical method for merely **identifying the presence and pattern of a faded tattoo** on skin, especially in a postmortem context. *Illuminate with ordinary light* - **Ordinary visible light** is typically insufficient to reveal tattoos that have significantly faded or been subjected to processes that obscure them. - If the tattoo is already faded to the point of being invisible to the naked eye, **ordinary light will not enhance its visibility** as it lacks the specific wavelengths needed to cause fluorescence. *Perform an X-ray examination* - **X-rays** are used to visualize dense structures like **bones and foreign bodies**, not for examining skin or pigments. - Tattoo pigments are generally **not radiopaque** and would not be visible on an X-ray film, rendering this method useless for tattoo identification.
Question 10: Which of the following is NOT a post-mortem finding in carbon monoxide poisoning?
- A. Froth at mouth and nose
- B. Blue skin discoloration (Correct Answer)
- C. Cerebral edema
- D. Cherry red discoloration of skin
Explanation: ***Blue skin discoloration*** - **Cyanosis**, or blue skin discoloration, indicates **hypoxia** due to deoxygenated hemoglobin. - In carbon monoxide poisoning, **carboxyhemoglobin** prevents oxygen release but does not cause deoxygenation of the remaining hemoglobin, thus typically avoiding cyanosis. *Froth at mouth and nose* - **Frothing** at the mouth and nose can be seen in various forms of asphyxia and pulmonary edema, which can be secondary to carbon monoxide poisoning if there is significant cardiac or respiratory compromise. - While not universally present, it is a possible finding associated with acute physiological distress preceding death. *Cerebral edema* - **Cerebral edema** is a common post-mortem finding in severe carbon monoxide poisoning due to **hypoxic brain injury**. - Carbon monoxide directly impairs cellular respiration, leading to widespread tissue hypoxia, including the brain, which can manifest as swelling. *Cherry red discoloration of skin* - **Cherry red discoloration** of the skin and lividity is a classic and highly characteristic post-mortem sign of carbon monoxide poisoning. - This color is due to the formation of **carboxyhemoglobin**, which has a bright red hue and is visible through the skin.
Want unlimited practice?
Get full access to all questions, explanations, and performance tracking.
Start For Free