Skeletal and Dental Age Determination MCQs

From the given options, mineralization of teeth is the more accurate method of age determination in childhood . The relationship between the chronological age and dental age is stronger than between chronological age and skeletal age. Two aspects of tooth development have been used in the estimation of dental age: The emergence of teeth - superior part of the crown of the tooth appearing level with the surface of the alveolar bone The stage of mineralization of crowns and roots during development Mineralization of teeth begins at 14 weeks in utero and lasts for a long time after birth. Two important processes in tooth development, dentinogenesis and amelogenesis, are responsible for the formation of dentin and enamel, respectively. Reference ; Encyclopedia of Forensic and Legal Medicine, Page no. 125

Tooth length is not assessed in Gustafson's method. Gustafson's method of estimation of age of an individual is based on physiological changes in teeth. It is mainly useful in adults over 25 years of age. Gustafson criteria includes: Attrition - Wear and tear changes of occlusal surface Periodontosis - Regression of gums surrounding the tooth resulting in loosening of the tooth and falling Secondary dentin formation - Deposition of dentin in pulp cavity Cementum apposition - Deposition of cementum in the root forming incremental lines Root resorption - Involves both cementum and dentin Transparency of the root - This is the most reliable criteria. Canals in dentin get filled with mineral and they become less transparent. Reference: The Essentials of Forensic Medicine & Toxicology, KS Narayan Reddy, 35th edition, Page No. 50, 51.

Explanation: The pelvis is most reliable single bone for sex determination of an unknown individual. The accuracy in sex determination by the pelvis alone is 95%. The femur is the most useful long bone for sex determination, due to its length and massiveness. Krogman's degree of accuracy in sex determination from adult skeletal remains: Entire skeleton - 100% Pelvis alone - 95% Skull alone - 92% (Option B) Pelvis plus skull - 98% Long bones plus pelvis - 98% Long bones alone - 80% (Option C & D)

Explanation: The talus starts its ossification process around the 7th month of intrauterine life . During this stage, an ossification center appears in the talus, marking the transition from cartilage to bone tissue. Like other fetal bones, the timing of ossification of the talus is well defined and is a key milestone in skeletal development. Explanation of Other Options: 3 months (Option A): At this stage, the talus exists purely in a cartilaginous form, with no ossification initiated. 9 months (Option C): By full term, the talus is already ossifying, but the process began earlier, at 7 months, not at 9. 2 months (Option D): Too early for ossification, as the fetal skeletal system is still predominantly cartilaginous at this point. Reference: Talus

Transparency of the root is the most reliable criteria. Gustafson's method of estimation of age of an individual is based on physiological changes in teeth. It is mainly useful in adults over 25 years of age. Gustafson criteria includes: Attrition - Wear and tear changes of occlusal surface Periodontosis - Regression of gums surrounding the tooth resulting in loosening of the tooth and falling Secondary dentin formation - Deposition of dentin in pulp cavity Cementum apposition - Deposition of cementum in the root forming incremental lines Root resorption - Involves both cementum and dentin Transparency of the root - This is the most reliable criteria. Canals in dentin get filled with mineral and they become less transparent. Reference: The Essentials of Forensic Medicine & Toxicology, KS Narayan Reddy, 35th edition, Page No. 50, 51.

Explanation: The gestational age of this fetus is 6-7 months. Crown heel length (CHL) = Crown-rump length (CRL) + Length of lower limb The rule of Haase and Morrison's rule enables the estimation of the gestational age of the fetus in lunar months from its crown-heel length (in cm). According to the Rule of Haase , if the crown-heel length is less than 25 cm , Gestational age (GA) in lunar months = Square root of crown-heel length (GA = √CHL) According to Morrison's rule, if the crown-heel length is more than 25 cm, Age in lunar months = crown-heel length divided by 5 . (GA = CHL/5) Here, Crown heel length = Crown-rump + lower limb length = 21cm + 10cm = 31 cm. Hence, gestational age = 31 / 5 = 6.2, i.e., 6-7 months.

Explanation: Rule of Hasse is applied for estimating fetal age up to 5 months : Age (months) = Square root of crown heel length (cm) Thus, √25 = 5 → Age = 5 months . For fetuses beyond 5 months , Morrison’s rule applies: Age (months) = Crown heel length (cm) / 5 Key takeaways: Rule of Hasse for ≤5 months, Morrison’s rule for >5 months. CHL is a reliable fetal age estimator during autopsy. Helps in medicolegal estimation of viability and gestational age. References: Age

Gestational age of this foetus is 6-7 months. Crown rump length + Length of lower limb = Crown heel length Rule of Haase and Morrison's rule enables the estimation of the gestational age of the foetus in lunar months from its crown-heel length (in cm). According to Rule of Haase, if the crown-heel length is less than 25 cm, Age in lunar months = Square root of crown-heel length According to Morrison's rule, if the crown-heel length is more than 25 cm, Age in lunar months = crown-heel length divided by 5. Here, crown heel length = Crown rump + lower limb length = 31 cm. Hence, gestational age = 31 / 5 = 6-7 months. Reference: Knight's Forensic Pathology, 4 th Edition, Page No. 459. The Essentials of Forensic Medicine & Toxicology, KS Narayan Reddy, 35th Edition, Page No. 61.