OBS Quiz Flashcards
Jim is an 82 year old bricklayer, has been diagnosed with squamous cell carcinoma of the lower lip.
Which of the following lymph nodes was first involved in the spread of the cancer cells?
Submental nodes
Cells that are responsible for the production of reactive dentin are most likely to present in which of the following areas of pulp?
Pulp periphery
The oral bacteria that is associated with the initiation of dental caries is:
Mutans streptococci
Further info: lactobacillus is associated with caries progression
Which of the following does not provide supportive evidence of the role of mutans streptococci in dental caries?
The ability to breakdown collagen using pro teases.
Which pattern of inheritance is the following genetic tree referring to? (Black circles and squares)
Mitochondrial inheritance
Regarding odontoblasts and their processes
Odontoblast processes branch dichotomously at the dentinoenamel junction (DEJ) and may sometimes be incorporated into enamel as enamel spindles
Eutetic point defines
Binary alloy formulation that has a single melting point
Oral fungal infections that appear as a creamy white, loosely adherent membrane covering the various oral surfaces may be caused by:
Candida albicans
In relation to bio materials, stiffness refers to
Resistance to elastic deformation
Herpangina and hand, foot and mouth disease are infections that have prominent oral manifestations appearing particularly as vesicles. These infections are caused by:
Type A coxsackie viruses
Regarding pulp
It includes undifferentiated cells some of which may differentiate into odontoblasts
Which statement regarding dental cements is INCORRECT?
Eugenia in zinc oxide-Eugenia cement has inflammatory effect on the tissue
The incident laser beam travels through the thickness of human cementum at the incident angle of pi/3. The refractive index of human cementum is 1.58. What is the refractive index of human dentine if the refractive angle was pi/2.87?
1.54
The difference in staining between GRam positive and gram negative organisms:
Is determined by their cell wall structure
Regarding to Thea quirked tooth pellicle, which of the following statement is NOT TRUE?
Can be readily removed from teeth by tooth brushing
Which is NOT correct regarding the chronology of the human development?
Upper lip and palate fusion is complete at six weeks of development
Which artery is a branch of the maxillary artery?
Infra-orbital
The tongue includes the following features:
Lingual papillae which include vallate papillae and filiform papillae
If the facial nerve was cut as it exited the stylomastoid foramen, which of the following muscles would NOT be affected?
Stapedius
Explanation: the facial nerve originates in the pons, traverses the facial canal of the temporal bone, and exits the cranium through the stylomastoid foramen and then extends laterally around the neck of the mandible through th parotid gland. With the exception of the stapedial nerve, all branchiomotor fibres in the facial nerve emerge from the facial canal via the stylomastoid foramen. The branchial motor of facial nerve supplies the muscles of facial expression, posterior or anterior belly of digastric muscle, stylohyoid.
HArdness of human dentine specimen was measured using microindentation instrument. The indentation experiment was conducted at 20mN force and resulted in the residual impression area of 18.52 cm^2. What was the hardness of the specimen?
1.08 GPa
A person eats a starch rich diet. Saliva from which of the following glands is most likely to produce amylase to digest this food?
Parotid glands
Linear coefficient of thermal expansion of human enamel is 25 x 10^-6 C^o-1. What is the human enamel volumetric coefficient of thermal expansion?
75 x 10^-6 C^o-1
The structure depicted at the arrow is a: (dental papilla histology image)
Successional laminators
Advantages for microorganisms living within a dental plaque (biofilm) include all of the following except:
Production of bacteriocins within the biofilm.
Reason: bacteriocins are antimicrobial agents which suppress competing microorganisms.
