Dentosphere : World of Dentistry

 # Fishman’s index is used in relation with: A. Population B. Hand-wrist radiographs C. Cephalograms  D. Periodontal diseases The correct answer is B. Hand-wrist radiographs. The following are the most commonly used methods for determination of skeletal maturity through hand-wrist xrays:  - Atlas method by Greulich and Pyle - Bjork Grave and Brown method - Singer's method of assessment - Fishman's skeletal maturity indicators - Hagg and Taranger method CLICK HERE FOR MORE MCQs

 # Carpal radiograph is used for assessment of: A. Bone condition B. Chronological age C. Treatment plan D. Skeletal maturation The correct answer is: D. Skeletal Maturation. There are different methods to assess the skeletal maturity of an indivudual which include: 1. Use of hand wrist radiographs 2. Evaluation of skeletal maturation using cervical vertebrae 3. Assessment of maturity by clinical and radiographic examination of different stages of tooth (Lower third molar) Hand wrist radiograph is the most reliable among all these.  CLICK HERE FOR MORE MCQs

 # A vestibuloplasty procedure is performed by: A. Reducing buccal bone from the alveolar ridge with a barrel bur and a handpiece B. Apically repositioning the muscular and mucosal attachments of the mandible C. Reflecting the gingiva and using Rongeurs to remove bone from the alveolar crest D. Using a bone file to smooth rough bony projections E. Grafting harvested iliac or rib bone onto the alveolar process The correct answer is B. Apically repositioning the muscular and mucosal attachments of the mandible Vestibuloplasty is a procedure performed to lengthen the residual ridge and deepen the oral vestibule. A vestibuloplasty can only be achieved by relocating or repositioning the muscle attachments and mucous membrane covering it into a deeper or more apical position.  Vestibuloplasties are also accompanied with the use of a mucosal graft or a skin graft.  CLICK HERE FOR MORE MCQs

 # The most ideal finish line configuration for a porcelain veneer is: A. Feather B. Chamfer C. Shoulder D. Chisel The correct answer is: C. Shoulder. #Shoulder Finish Line Indications: • All ceramic crowns • PFM crowns • Injectable porcelains  Advantages:  • Good crown contours • Esthetics  • Less distortion • Provides adequate bulk Disadvantages: • Least conservative • Inferior marginal adaptation # Shoulder with bevel Finish Line Indications: • Proximal boxes of onlays and inlays • Labial finish line of metal ceramics • Occlusal shoulder of onlays  Advantages:  • Superior marginal adaptation • Resists distortion • Facilitates removal of unsupported enamel rods Disadvantages: • Requires subgingival extension • Detection of post cementation caries is difficult # Chamfer Finish Line Indications: • Cast metal restorations • Lingual aspect of metal ceramics Advantages:  • Conservative • Good marginal adaptation • Provides bulk Di...

 # The preferred gingival finish line for veneer metal restoration is: a) Shoulder  b) Chamfer c) Shoulder with bevel  d) Radial shoulder The correct answer is B. Chamfer. #Shoulder Finish Line Indications: • All ceramic crowns • PFM crowns • Injectable porcelains  Advantages:  • Good crown contours • Esthetics  • Less distortion • Provides adequate bulk Disadvantages: • Least conservative • Inferior marginal adaptation # Shoulder with bevel Finish Line Indications: • Proximal boxes of onlays and inlays • Labial finish line of metal ceramics • Occlusal shoulder of onlays  Advantages:  • Superior marginal adaptation • Resists distortion • Facilitates removal of unsupported enamel rods Disadvantages: • Requires subgingival extension • Detection of post cementation caries is difficult # Chamfer Finish Line Indications: • Cast metal restorations • Lingual aspect of metal ceramics Advantages:  • Conservative • Good marginal ada...

 # Partial veneer crown is contraindicated in: a) Long teeth  b) Short teeth c) Tipped teeth  d) Tapered teeth The correct answer is B. Short Teeth. Indications for partial veneer crown: • Intact or minimally restored teeth . • Teeth with normal anatomic crown form i.e., without excessive cervical constriction. • Teeth with adequate crown Length. Contraindications for partial veneer crown: • High caries rate. • Short teeth. • Bell shaped teeth. • Teeth with insufficient buccolingual width. • Excessively restored teeth. CLICK HERE FOR MORE MCQs

 # In partial veneer crown, retention can be increased by: a) Increased length of path of insertion b) Increase in taper c) Making path of removal parallel to long axis of adjacent teeth d) None of the above The correct answer is A. Increased length of path of insertion. Crown preparation with long, parallel axial walls and grooves produces maximum retention. Increasing the taper decreases retention. A short, over tapered preparation, decreases the retention because the restoration can be removed along an infinite number of paths. CLICK HERE FOR MORE MCQs

 # The amount of reduction required for a tooth for all metal crown restoration is: a) So that there is proper clearance between the teeth b) So that the tooth architecture interferes with the arch of rotation c) So that the tooth architecture doesn't interfere with the arch of rotation d) At least 2mm on all the surfaces The correct answer is: B. So that the tooth architecture interferes with the arch of rotation The longer the occlusogingival length of the preparation, the greater is the retention. This is because longer preparations interfere with the arc of the casting pivoting about a point than shorter preparations. CLICK HERE FOR MORE MCQs

 # Finish lines of a complete coverage crown should lie? a) Supragingivally  b) Subgingivally c) Subgingival if required d) Gingival margin The correct answer is C. Subgingival if required.  Whenever possible the finish lines of crowns should terminate supragingivally. Subgingival margins are required in the following situations. • Esthetics. • Cervical erosion and caries. • Insufficient crown length for retention. • Elimination of persistent root hyper sensitivity. CLICK HERE FOR MORE MCQs

 # Which of the following is a paired cartilage of larynx? A. Thyroid B. Cricoid C. Epiglottis D. Arytenoid The correct answer is D. Arytenoid. The laryngeal skeleton is made of nine cartilages: the thyroid cartilage, cricoid cartilage, epiglottis, arytenoid cartilages, corniculate cartilages, and cuneiform cartilages. The first three are unpaired cartilages, and the latter three are paired cartilages. Paired = Arytenoid, Corniculate, Cuneiform Unpaired= Thyroid, Cricoid, Epiglottis CLICK HERE FOR MORE MCQs

 # Larynx extends from: A. C2-C7 B. C1-C4 C. C5-C6 D. C3-C6 The correct answer is D. C3-C6 Larynx is the organ of voice (Phonation), an air passage sphincter at the inlet of the lower respiratory passage. In adult male, it lies opposite to third, fourth, fifth, sixth cervical vertebrae, but in children, and in adult female, it lies at a higher level. CLICK HERE FOR MORE MCQs

 # The arterial supply of trachea is by the: A. Bronchial artery B. Tracheal artery C. Inferior thyroid artery D. Superior thyroid artery The correct answer is C. Inferior thyroid artery. Inferior thyroid artery is a branch of thyrocervical trunk, which arises from the subclavian artery. Its terminal part is related to recurrent laryngeal nerve. Apart from trachea, it also supplies lower two thirds of thyroid lobe and lower half of the isthmus, parathyroid, thymus, larynx, pharynx, and the surrounding muscles.  CLICK HERE FOR MORE MCQs

 # Trachea bifurcates at the level of: A. C7 B. Lower border of T3 C. Upper border of T4 D. Upper border of T5 The correct answer is D. Upper border of T5. Trachea begins at C6 and bifurcates at the level of T5. Trachea bifurcates at the level of sternal angle. CLICK HERE FOR MORE MCQs

 # Select the incorrect statement about the carotid sinus: A. It is a dilatation near the beginning of the internal carotid artery B. It is innervated by the glossopharyngeal nerve C. It acts as a chemoreceptor D. Its wall has thick tunica adventitia The correct answer is C. It acts as a chemoreceptor; which is incorrect because carotid sinus is a baroreceptor.  Carotid Sinus : The termination of the common carotid artery, or the beginning of the internal carotid artery shows a slight dilatation, known as the carotid sinus which receives a rich innervation from the glossopharyngeal and sympathetic nerves. The carotid sinus acts as a baroreceptor or pressure receptor and regulates blood pressure. Carotid Body: Carotid body is a small, oval reddish-brown structure situated behind the bifurcation of the common carotid artery. It receives a rich nerve supply mainly from the glossopharyngeal nerve, but also from the vagus and sympathetic nerves. It acts as a chemoreceptor and respo...

# The base of the submental triangle is formed by: A. Chin B. Anterior belly of digastric C. Posterior belly of digastric D. Hyoid bone The correct answer is D. Hyoid bone. Submental triangle is a median triangle. On each side, there is the anterior belly of the corresponding digastric muscles. Its base is formed by the body of the hyoid bone. Its apex lies at the chin. The floor of the triangle is formed by the right and left mylohyoid muscles and the median raphe uniting them. CLICK HERE FOR MORE MCQs

 # All of the infrahyoid muscles are supplied by ansa cervicalis EXCEPT: A. Thyrohyoid B. Sternohyoid C. Sternothyroid D. Inferior belly of omohyoid The correcct answer is A. Thyrohyoid. Infrahyoid muscles are sternohyoid, sternothyroid, thyrohyoid and omohyoid present in the superficial plane of the anterior triangle of neck. Sternohyoid, sternothyroid, omohyoid are supplied by ansa cervicalis EXCEPT thyrohyoid which is supplied by the first cervical nerve through hypoglossal nerve. CLICK HERE FOR MORE MCQs

 # All of the following belongs to suprahyoid group of muscles EXCEPT: A. Omohyoid B. Mylohyoid C. Stylohyoid D. Geniohyoid The correct answer is A. Omohyoid.  Suprahyoid Muscles are: Digastric, Stylohyoid, Mylohyoid, Geniohyoid   @ Super Stylish Getho and Mylo Di.  Infrahyoid muscles: Sternohyoid, Sternothyroid, Thyrohyoid, Omohyoid  (SH, ST, TH, OH) CLICK HERE FOR MORE MCQs

 # Torticollis or Wry Neck is the result of spasm of which of the following muscles? A. Omohyoid and sternohyoid B. Trapezius and Sternocleidomastoid C. Platysma and mentalis D. Scaleneus anterior and scaleneus posterior The correct answer is B. Trapezius and Sternocleidomastoid Torticollis or Wry neck is a deformity in which the head is bent to one side and the chin points to the other side. This is a result of spasm or contracture of the muscles supplied by the spinal accessory nerve, these being the sternocleidomastoid and the trapezius. CLICK HERE FOR MORE MCQs

 # Which of the following are called as ‘Signal nodes’? A. Supraclavicular nodes B. Jugulo-omohyoid C. Jugulodigastric D. Submandibular The correct answer is A. Supraclavicular nodes The left supraclavicular nodes or Virchow's or scalene nodes are also involved in malignant growths of distant organs, e.g. the stomach, the testis and other abdominal organs. Therefore, they are known as signal nodes. Scalene node biopsy is very helpful in the early diagnosis of such malignancies.  CLICK HERE FOR MORE MCQs

 # The origin of clavicular head of sternocleidomastoid muscle is from the: A. Medial one third of the inferior surface of the clavicle B. Lateral one third of the inferior surface of the clavicle C. Medial one third of the superior surface of the clavicle D. Lateral one third of the superior surface of the clavicle The correct answer is C. Medial one third of the superior surface of the clavicle. Origin of Sternocleidomastoid Muscle 1. The sternal head is tendinous and arises from the superolateral part of the front of the manubrium sterni. 2. The clavicular head is musculotendinous and arises from the medial one third of the superior surface of the clavicle. Insertion of Sternocleidomastoid Muscle It is inserted  a) by a thick tendon into the lateral  surface of the mastoid process from its tip to its superior border, and  b) by a thin aponeurosis into the lateral half of the superior nuchal line of the occipital bone. Nerve Supply of Sternocleidomastoid The spinal...

 # Following is the action of digastric muscle: A. Elevates the mandible and depresses the hyoid bone B. Elevates the hyoid bone and depresses the mandible C. Depresses the mandible as well as hyoid bone D. Elevates the mandible as well as hyoid bone The correct answer is B. Elevates the hyoid bone and depresses the mandible. Digastric muscle depresses the mandible when the mouth is opened widely or against resistance and elevates the hyoid bone. CLICK HERE FOR MORE MCQs

 # Temporalis muscle originates from: A. Side of the skull B. Zygomatic process C. Ramus of the mandible D. Pterygopalatine fossa The correct answer is A. Side of the skull. Temporalis muscle arises from temporal fossa and temporal fascia and inserts into deep surface of coronoid and anterior border of the ramus of mandible.  CLICK HERE FOR MORE MCQs WATCH THIS VIDEO TO KNOW ABOUT ORIGIN AND INSERTION OF ALL THE MUSCLES OF MASTICATION:

 # Medial pterygoid muscle is attached to: A. Medial surface of lateral pterygoid plate B. Lateral surface of medial pterygoid plate C. Medial surface of medial pterygoid plate D. Lateral surface of lateral pterygoid plate The correct answer is A. Medial surface of the lateral pterygoid plate Deep head of the medial pterygoid muscle arises from medial surface of lateral pterygoid plate and palatine bone. The lateral pterygoid muscle arises from lateral surface of lateral pterygoid plate. CLICK HERE  FOR MORE MCQs

 # Lymphatic drainage of TMJ is mainly to: A. Submandibular nodes B. Submental nodes C. Deep cervical nodes D. Parotid nodes The correct answer is D. Parotid nodes. CLICK HERE FOR MORE MCQs

 # Which of the following supplies capsule of TMJ? A. Facial nerve B. Auriculotemporal nerve C. Branch of maxillary nerve D. First cervical nerve The correct answer is B. Auriculotemporal nerve. Sensory nerve supply: Sensory innervation of the TMJ is derived from the auriculotemporal and masseteric branches of V3 (otherwise known as the mandibular branch of the trigeminal nerve). Blood supply of TMJ: Its arterial blood supply is provided by branches of the external carotid artery, predominantly the superficial temporal branch. Other branches of the external carotid artery, namely, the deep auricular artery, anterior tympanic artery, ascending pharyngeal artery, and maxillary artery, may also contribute to the arterial blood supply of the joint. CLICK HERE FOR MORE MCQs

 # Which of the following are dynamic receptors of the TMJ joint? A. Ruffini endings B. Pacinian corpuscles C. Golgi tendon D. Free nerve endings The correct answer is B. Pacinian corpuscles Pacinian corpuscles  are dynamic mechanoreceptors which accelerate movement during reflexes.  The receptors for specific mechanics of proprioception: Ruffini endings- static  mechanoreceptors which position the mandible Pacinian corpuscles- Dynamic mechanoreceptors which accelerate movement during reflexes Golgi tendon organs- Static mechanoreceptors for protection of ligaments around the temporomandibular joint Free nerve endings- Pain receptors for protection of the temporomandibular joint itself CLICK HERE FOR MORE MCQs

 # Articular disc of TMJ is: A. Fibrocartilaginous B. Bony C. Hyaline cartilage D. Elastic cartilage The correct answer is A. Fibrocartilaginous The unique feature of the TMJ is the articular disc. The disc is composed of fibrocartilaginous tissue which is positioned between the two bones that form the joint. There is neither innervation nor vascularization within the central portion of the articular disc. Articular disc is oval fibrous plate with concavoconvex superior surface and concave inferior surface. It divides joint into upper and lower compartments. Upper compartment permits gliding and lower permits gliding as well as rotatory movements.  CLICK HERE FOR MORE MCQs

 # Sublingual salivary gland is located superior to: A. Genioglossus B. Hyoglossus C. Mylohyoid D. None of the above The correct answer is C. Mylohyoid. Sublingual salivary gland lies superior to mylohyoid and lateral to the genioglossus muscle. Its duct opens directly into floor of mouth on the summit of sublingual fold. CLICK HERE FOR MORE MCQs

 # The opening of submandibular gland duct into oral cavity is at: A. Maxillary Second molar B. Mandibular third molar C. Dorsum of tongue D. Sublinugual caruncle The correct answer is D. Sublingual caruncle. Submandibular duct or Warthin's duct is 5 cm long, emerges from submandibular gland and in its course runs on the hyoglossus between lingual and hypoglossal nerve and opens at the sublingual papilla at the side of frenum of tongue. CLICK HERE FOR MORE MCQs

 # For an Ideal class V restoration on a mandibular premolar, which of the following is the MOST IMPORTANT factor when choosing a restorative material? A. Ease of manipulation of material B. Esthetics C. Compressive strength D. Reaction of gingival tissue The correct answer is D. Reaction of gingival tissue. Restorative materials that do not induce gingival tissue reaction should be considered when selecting the proper restorative material for class V restorations. Esthetics are not a factor because the class V restoration in question is placed at the cervical area of a mandibular premolar and is not within the esthetic zone. Compressive strength is only required for occlusal restorations or those cavities which are under heavy occlusal load. CLICK HERE FOR MORE MCQs

 # Secretomotor fibres from inferior salivary nucleus supply: A. Lacrimal gland B. Parotid gland C. Submandibular salivary gland D. Sublingual salivary gland The correct answer is B. Parotid gland. The preganglionic fibres begin in the inferior salivatory nucleus, pass through the 9th cranial nerve and relay in the otic ganglion. The post ganglionic fibres reach the gland through the auriculotemporal nerve. # Inferior salivatory nucleus --> IX cranial nerve tympanic branch ----> tympanic plexus ---> Lesser petrosal nerve ---> relays in otic ganglion ---> parotid gland. # Edinger westphal nucleus ---> III nerve ---> Inferior oblique ---> Branch to ciliary ganglion ---> relay ---> short ciliary nerves supply cliliaris and constrictor pupillae muscle. # Superior salivatory nucleus of VII nerve ---> VII nerve ---> chorda tympani branch --->  via lingual nerve ---> submandibular ganglion ---> relays ---> submandibular gland and lingua...

 # The orifice of parotid duct is located: A. At the hamular notch B. In proximity to the incisive papilla C. On the buccal mucosa near the maxillary second molar D. Slightly posterior to the mandibular central incisors The correct answer is C. On the  buccal mucosa near the maxillary second molar Parotid duct is 5 cm long, thick walled and it emerges from anterior border of the gland and runs on the masseter muscle. At the anterior border of masseter it turns medially and pierces:  Buccal pad of fat Buccopharyngeal fascia Buccinator (obliquely) Then, the duct runs forwards and obliquely for a short course between buccinator and oral mucosa. This acts as  a valve which prevents inflation of ductt during blowing. Finally it opens into the vestibule of mouth, at upper second molar tooth.  CLICK HERE FOR MORE MCQs

 # Which of the following is predominantly mucous? A. Parotid gland B. Submandibular gland C. Sublingual gland D. Von  Ebner’s gland The correct answer is C. Sublingual gland. Sublingual gland is a mixed gland and is predominantly mucous. @ MuSuLi. Parotid gland is purely serous gland. @ SerPa Submandibular gland is mixed gland and is predominantly serous. CLICK HERE FOR MORE MCQs

# Number of somatic chromosomes in humans is: A. 42 B. 41 C. 46 D. 44 # Which of the following is true of meiosis? A. It exclusively takes place in somatic cells B. At the end, same number of chromosomes are maintained in the daughter cells C. Only two daughter cells are formed at the end of meiosis D. Crossing over and genetic variability is enhanced