ORPTH ADONS DSE of OSSEOUS STRUCTUREs

Question 1

1. Anomalies or malformations of individual bones or their pairs
   is referred to as
   (a) Dysplasia
   (b) Dysostosis
   (c) Dystrophy
   (d) Enostosis

Answer 1

(b) Dysostosis refers only to defects or malformations of
individual or pairs of bones and does not refer to any
generalized disorder of the skeleton.

Question 2

2. Generalized abnormalities of cartilage or bone growth and
   development is called as
   (a) Osteochondrodysplasia
   (b) Osteochondrometaplasia
   (c) Osteoid dysplasia
   (d) Chondrometaplasia

Answer 2

(a) This term signifies a generalized disorder of skeletal system
involving multiple bones at the time of presentation.

Question 3

3. Lobstein’s disease is another name of
   (a) Osteogenesis imperfecta
   (b) Dentinogenesis imperfecta
   (c) Osteopetrosis
   (d) Paget’s disease

Answer 3

(a) Osteogenesis imperfecta comprises a heterogeneous group of
heritable disorders characterized by impairment of collagen
maturation.

Question 4

4. Osteogenesis imperfecta results from an abnormality in _______
   collagen.
   (a) Type III (b) Type II
   (c) Type I (d) Type IV

Answer 4

(c) Abnormal maturation of collagen results in bone with a thin
cortex, fine trabeculation, and diffuse osteoporosis

Question 5

5. In which of the following diseases is pale blue sclera not seen?
   (a) Paget’s disease
   (b) Marfan syndrome
   (c) Ehlers-Danlos syndrome
   (d) Pierre Robin anomalad

Answer 5

(d) This anomaly comprises of three skeletal components, i.e.
micrognathia, cleft palate and glossoptosis.

Question 6

6. Characteristic skeletal defects like arachnodactyly, dolichostenomelia and hyperextensibility of joints are featuresof
   (a) Pierre Robin anomalad
   (b) Ehlers-Danlos syndrome
   (c) Cleidocranial dysostosis
   (d) Marfan syndrome

Answer 6

. (d) This is a spectrum of disorders caused by a heritable genetic
defect of connective tissue that has an autosomal dominant
mode of transmission.

Question 7

7. Hypophosphatasia is a rare inherited metabolic disorder which
   refers to a lack of
   (a) Alkaline phosphatase (b) Acid phosphatase
   (c) Hydroxyapatite (d) Calcium phosphate

Answer 7

(d) It is a disease of decreased tissue nonspecific alkaline
phosphatase TNSALP and defective mineralization. A
mutation in the ALPL gene, coding for TNSALP is believed
to be the cause.

Question 8

8. Failure of osteoclasts to resorb bone thereby resulting in
   thickened sclerotic bones with reduced mechanical strength is
   a characteristic feature of
   (a) Osteogenesis imperfecta
   (b) Osteopetrosis
   (c) Paget’s disease
   (d) Fibrous dysplasia

Answer 8

(b) Defective osteoclastic bone resorption, combined with
continued bone formation and endochondral ossification,
results in thickening of cortical bone and sclerosis of the
cancellous bone

Question 9

9. Hyperparathyroidism is most commonly associated with which
   syndrome?
   (a) von Recklinghausen’s disease
   (b) Cleidocranial dysostosis
   (c) Multiple endocrine neoplasia Type 1
   (d) Fibrous dysplasia

Answer 9

(c) It is a syndrome of hypercalcemia caused by excessive
release of the parathyroid hormone. In 85% of cases primary
hyperparathyroidism results from an adenoma in a single
gland.

Question 10

12. The common site of involvement of polyostotic form of fibrous
    dysplasia is
    (a) Bones of skull and face (b) Femur
    (c) Ribs (d) Spine

Answer 10

(a) Involvement of the mandible often results not only in
expansion of the lingual and buccal plates but also bulging of
the lower border. When the maxilla is involved, the lesional
tissue displaces the sinus floor superiorly and commonly
obliterates the maxillary sinus

Question 10

10. Monostotic form, polyostotic form, craniofacial form and
    cherubism are disease patterns of which disease?
    (a) Paget’s disease
    (b) Fibrous dysplasia
    (c) Cleidocranial dysostosis
    (d) Brown’s tumor

Answer 10

(b) It is a developmental tumor-like condition characterized by
replacement of normal bone by an excessive proliferation of
cellular fibrous connective tissue intermixed with irregular
bony trabeculae.

Question 11

11. Large café-au-lait spots with irregular margins, precocious
    puberty and a “ground glass” appearance of affected bones
    (a) Paget’s disease (b) Pierre Robin anomalad
    (c) Fibrous dysplasia (d) Osteogenesis imperfecta

Answer 11

(c) Polyostotic fibrous dysplasia (affecting multiple bones)
along with café-au-lait spots is termed Jaffe-Lichtenstein
syndrome and if it occurs along with café-au-lait spots
and multiple endocrinopathies, then it is termed McCuneAlbright syndrome.

Question 12

13. All of the following except __________________ are histological
    features found in fibrous dysplasia.
    (a) Irregular, Chinese character-shaped bony trabeculae
    (b) Osteoblastic rimming of bony trabeculae
    (c) Larger than normal osteoblasts
    (d) Collagen fibers of trabeculae extending into fibrous tissue

Answer 12

(b) Rimming by plump appositional osteoblasts is missing in
fibrous dysplasia as the bone trabeculae in this disease are
produced as a result of metaplasia.

Question 13

14. The most common malignancy arising in fibrous dysplasia is
    (a) Fibrosarcoma (b) Osteosarcoma
    (c) Ewing’s sarcoma (d) Multiple myeloma

Answer 13

(b) Osteosarcoma developing in fibrous dysplasia has been
reported in patients who received radiation therapy for
the treatment of this disease. Hence, radiotherapy is
contraindicated.

Question 14

15. McCune-Albright syndrome is also better known as
    (a) Monostotic fibrous dysplasia
    (b) Paget’s disease
    (c) Polyostotic fibrous dysplasia
    (d) Hyperparathyroidism

Answer 14

(c) When polyostotic fibrous dysplasia occurs along with café-
au-lait pigmentation and multiple endocrinopathies, then
it is termed McCune-Albright syndrome.

Question 15

16. A hereditary nonneoplastic bone lesion, histologically similar to
    central giant cell granuloma and affecting the jaws of children
    bilaterally is called as
    (a) Monostotic fibrous dysplasia
    (b) Cherubism
    (c) Hypophosphatasia
    (d) Brown’s tumor

Answer 15

(b) Cherubism is a rare developmental jaw condition that is
generally inherited as an autosomal dominant trait with
high penetrance but variable expressivity.

Question 16

17. Phosphate diabetes is also known as
    (a) Hypophosphatasia (b) Renal rickets
    (c) Hypophosphatemia (d) Vitamin D resistant rickets

Answer 16

(d) Vitamin D resistant rickets refers to an autosomal dominant
genetic condition due to which there is hypophosphatemia
leading to rickets, which cannot be cured even with high
doses of Vitamin D.

Question 17

18. Crouzon syndrome is most commonly associated with which
    skin lesion?
    (a) Dermatitis herpetiformis
    (b) White sponge nevus
    (c) Dyskeratosis congenita
    (d) Acanthosis nigricans

Answer 17

(d) Crouzon syndrome belongs to a group of anomalies called
craniosynostosis which refers to premature fusion of one
or more cranial sutures often resulting in abnormal head
shape.

Question 18

19. The primary defect in mandibulofacial dysostosis is
    (a) Failure of differentiation of mandibular mesoderm
    (b) Failure of differentiation of maxillary mesoderm
    (c) Failure of differentiation of 3rd arch mesenchyme
    (d) Failure of differentiation of 4th arch mesenchyme

Answer 18

(b) This is a hereditary disease following an irregular form
of dominant transmission and is thought to result from
retardation or failure of differentiation of maxillary arch
mesoderm at and after the 50 mm stage of embryo.

Question 19

20. Cleft palate, micrognathia and glossoptosis are components of
    ______ syndrome.
    (a) Treacher Collins (b) Crouzon
    (c) Pierre Robin (d) Apert

Answer 19

(c) Apart from the three anomalies, other associated anomalies
include otitis media, hearing loss, nasal deformities, dental
and philtral malformations.

Question 20

21. Histologically, the primary abnormality seen in the bones of
    patients with achondroplastic persons is
    (a) Abnormal trabeculae
    (b) Abnormal endochondral ossification
    (c) Abnormal intramembranous ossification
    (d) Abnormal periosteal ossification

Answer 20

(b) Achondroplasia is a common nonlethal chondrodysplasia transmitted as an autosomal dominant trait with
complete penetrance, resulting in decreased endochondral
ossification, decreased cellular hypertrophy, and decreased
cartilage matrix production

Question 21

22. In cleidocranial dysplasia, ___________ suture is characteristically
    sunken giving the skull a flat appearance.
    (a) Sagittal (b) Frontal
    (c) Temporal (d) Occipital

Answer 21

(a) It is an autosomal dominant disorder characterized by
clavicular hypoplasia/genesis with narrow thorax, delayed
ossification of skull, excessively large fontanels and delayed
closing of sutures

Question 22

23. Trisomy 21 syndrome is better known as _______ syndrome.
    (a) Down (b) Apert
    (c) Klinefelter (d) Ehlers-Danlos

Answer 22

(a) Down syndrome is a common form of mental retardation
resulting from trisomy 21, chromosomal translocation and
mosaicism. Trisomy refers to additional chromosome

Question 23

24. Which one of the following histological features is found in Paget’s
    disease?
    (a) Failure of endochondral ossification
    (b) Failure of fibroblastic maturation
    (c) Abnormal and excessive remodeling of bone
    (d) Abnormal collagen maturation

Answer 23

(c) Paget’s disease of bone is a disease characterized by
abnormal and anarchic resorption and deposition of bone,
resulting in distortion and weakening of the affected bones. The cause of Paget’s disease is unknown, but inflammatory,
genetic, and endocrine factors may be contributing factors.

Question 24

25. Infantile cortical hyperostosis is an _____ process of unknown
    etiology.
    (a) Viral (b) Inflammatory
    (c) Autoimmune (d) Developmental

Answer 24

(b) It is a syndrome of unknown etiology in which there is
unusual cortical thickening of certain bones in infants. It is
a self-limiting disorder and causes bone changes, soft tissue
swelling and irritability

Question 25

26. Characteristic “Cotton wool” appearance of involved bones is
    seen in
    (a) Fibrous dysplasia
    (b) Infantile cortical hyperostosis
    (c) Osteopetrosis
    (d) Paget’s disease

Answer 25

(d) During the osteoblastic phase of the disease, patchy areas of
sclerotic bone are formed, which tend to become confluent.
The patchy sclerotic areas often are described as having a
“cotton wool” appearance.

Question 26

29. All except ____ are considered as etiological factors of Paget’s
    disease of bones.
    (a) Viral (b) Bacterial
    (c) Vascular (d) Autoimmune

Answer 26

(b) Recent evidence suggests a genetic etiology as Paget’s
disease has been shown to be present in families. Some
studies have shown viral inclusions in pagetic osteoclasts

Question 27

27. Identify the sign which is not a cardinal sign of temporomandibular joint syndrome
    (a) Swelling over joint
    (b) Muscle tenderness
    (c) Clicking/popping noise in TMJ
    (d) Limitation of jaw movement

Answer 27

(a) TMJ disorder/syndrome is the most common cause
of facial pain after toothache. It is classified broadly as
TMD secondary to MPD and TMD secondary to true
articular disease. Its etiology is multifactorial and includes
malocclusion, bruxism, personality disorders, increased
pain sensitivity, stress and anxiety.

Question 28

28. Letterer-Siwe disease, eosinophilic granuloma and HandSchüller-Christian disease all belong to various clinical spectra
    of
    (a) Wegener’s granulomatosis
    (b) Robinow syndrome
    (c) Marfan syndrome
    (d) Langerhans cell histiocytosis

Answer 28

(d) It is a group of idiopathic disorders characterized by clonal
proliferation of Langerhans cells and mature eosinophils.
These disorders primarily affect bones, but occasionally also
affect other organ systems.

Question 29

30. Caffey’s disease is another name of
    (a) Histiocytosis X
    (b) McCune-Albright syndrome
    (c) Chondroectodermal dysplasia
    (d) Infantile cortical hyperostosis

Answer 29

(d) It is now believed to exist in two forms familial and sporadic.
The classical triad of presentation includes irritability,
swelling and bone lesions.