NBDE Part 1 - Dental Anatomy and Occlusion UPDATED ACTUAL Exam Questions and CORRECT Answers

NBDE Part 1 - Dental Anatomy and
Occlusion UPDATED ACTUAL Exam
Questions and CORRECT Answers
Which suprahyoid muscle are innervated by the facial nerve? - CORRECT ANSWER -=
Posterior Digastric and Stylohyoid


Infrahyoid Muscles - CORRECT ANSWER - = DEPRESSORS of the larynx and the hyoid
bone


1. Omohyoid (Ana Cervicalis, C1-C3)


2. Sternohyoid (Ana Cervicalis, C1-C3)


3. Sternothyroid (Ana Cervicalis, C1-C3)


4. Thyrohyoid (Ventral Ramus of C1 via Hypoglossal)


Which dental tissue most closely resembles bone? - CORRECT ANSWER - = CEMENTUM
- Cementum has COLLAGEN fibers and CELLULAR COMPONENTS (Cementocytes)


- have Acellular and Cellular cementum
- Cementoid is laid down first


Extrinsic Tongue Muscles - CORRECT ANSWER - 1. Genioglossus (Hypoglossal)
2. Hyoglossus (Hypoglossal)
3. Styloglossus (Hypoglossal)
4. Palatoglossus (VAGUS NERVE)

,Intrinsic Tongue Muscles - CORRECT ANSWER - 1. Superior Longitudinal
2. Inferior Longitudinal
3. Transverse Muscle
4. Vertical Muscle


***All of these are innervated by the HYPOGLOSSAL NERVE*****


Muscles of the Mouth/Facial Expression - CORRECT ANSWER - = are innervated by the six
branches of the Facial Nerve
- Posterior muscles = Posterior Auricular


- Anterior Muscles = 5 branches of the PAROTID PLEXUS (Temporal, Zygomatic, Buccal,
Mandibular, Cervical)


*When there's injury to the mandible (i.e., malignancy), to which side will it deviate?* -
CORRECT ANSWER - = TO THE SIDE OF INJURY
= if the hypoglossal nerve becomes damaged, the tongue will deviate TOWARD the affected side


muscles of mastication are innervated by - CORRECT ANSWER - Mandibular Division of
the Trigeminal Nerve (V3)


When the condylar head is fractured, what keeps it in the mandibular fossa? - CORRECT
ANSWER - = Temporomandibular Ligament



What muscle contracts during lateral excursive movements? - CORRECT ANSWER - = the
one lateral pterygoid muscle from the OPPOSITE SIDE
- so if the patient is moving their mandible to the right, the LEFT LATERAL PTERYGOID is
what contracts

, Gemination and fusion occur during which stage of tooth development? - CORRECT
ANSWER - = CAP STAGE (9-10th week)


- Dens in dente and Tubercle formation also occur during this time
- Proliferation, differentiation, and morphogenesis


Anodontia and Supernumerary teeth are a result of the interruption of which phase? - CORRECT
ANSWER - = INITIATION (6-7 week of gestation)
- Proliferation


During what stage does Macrodontia and Microdontia occur? - CORRECT ANSWER -=
BELL STAGE (11-12th week)
- Histodifferentiation and Morphodifferentiation


During what stage does Enamel Dysplasia, Concrescence, and Enamel Pearls occur? -
CORRECT ANSWER - = APPOSITION (varies per tooth)



How are accessory canals formed? - CORRECT ANSWER - = when the Hertwig's epithelial
root sheath encounters a blood vessel during root formation
- Root structure then forms around the vessel, forming the accessory canal


Which enamel organ layer becomes ameloblasts? - CORRECT ANSWER - = THE IEE (Inner
Enamel Epithelium)


Lines of Retzius - CORRECT ANSWER - = lines that terminate at the tooth surface and
create tiny valleys on the tooth surface that travel circumferentially around the crown
(PERIKYMATA or IMBRICATION LINES OF PICKERILL)
- *Neonatal Line* (division between enamel formed before birth and after)


Mandibular Second Premolar (Types) - CORRECT ANSWER - 1. Y-Type = 5 lobes, 3 cusps
(MOST COMMON)