22 Oral Anatomy & Charting Practice Questions & Answers

Every Oral Anatomy & Charting practice question from the Dental Assistant (DANB) Practice Test, with the correct answer and a short explanation.

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1. The dentist dictates, "existing amalgam, mesio-occluso-distal, permanent mandibular right first molar." Using the ADA Universal Numbering System and standard surface abbreviations, how should the assistant enter this in the chart?
- A.Tooth #30, surfaces DOM
- B.Tooth #3, surfaces MOD
- C.Tooth #19, surfaces MOD
- D.Tooth #30, surfaces MOD✓ Answer
Universal numbering starts at #1 (maxillary right third molar), runs across the maxillary arch to #16, drops to #17 (mandibular left third molar) and finishes at #32 (mandibular right third molar), which places the mandibular right first molar at #30; #19 is its mirror image on the left side. Combined-surface abbreviations are written in a fixed mesial-to-distal order in which every surface but the last changes its "-al" ending to "-o," giving mesio-occluso-distal = MOD.
Source: ADA Universal Tooth Designation System (permanent teeth 1-32) and ADA Dental Claim Form surface-code conventionsReport a problem with this question
2. A hygienist asks the assistant to chart a sealant placed on the patient's maxillary LEFT first permanent molar. Because the chart is laid out from the operator's viewpoint, the patient's right side appears on the left of the chart form. Which Universal number belongs in the entry?
- A.#30
- B.#14✓ Answer
- C.#3
- D.#19
Counting continuously from #1 at the maxillary right third molar, the maxillary left first molar is #14, while #3 is its mirror partner on the patient's right; the chart's mirrored layout is exactly why #3/#14 and #19/#30 are the most frequent charting errors. All four of these teeth (#3, #14, #19, #30) are the first permanent molars, the "six-year molars," and are the usual sealant teeth.
Source: ADA Universal Tooth Designation System; charting orientation from the operator's/viewer's perspectiveReport a problem with this question
3. A four-year-old needs a restoration on the primary tooth occupying the position where permanent tooth #9 will eventually erupt. Under the ADA Universal system for the primary dentition, which letter should the assistant chart?
- A.F✓ Answer
- B.E
- C.D
- D.J
Primary teeth are lettered A through T along the same path the numbers follow, so A is the maxillary right second primary molar, E is the maxillary right central incisor, F is the maxillary left central incisor and J is the maxillary left second primary molar. Since #9 is the permanent maxillary left central incisor, its primary predecessor is F, just as #8 corresponds to E.
Source: ADA Universal Tooth Designation System, primary dentition letters A-TReport a problem with this question
4. A new assistant trained on Palmer notation is confused because the letter A appears in both Palmer and Universal charting. Which statement correctly resolves the conflict?
- A.In both systems the letter A designates the maxillary right second primary molar, so the notations are interchangeable.
- B.In Palmer notation A is the primary central incisor of whichever quadrant the bracket indicates, while in the Universal system A is the maxillary right second primary molar.✓ Answer
- C.Palmer notation letters A through E number the primary teeth from the third molar region forward toward the midline.
- D.In Palmer notation A is the permanent maxillary right central incisor, while in the Universal system A is a primary central incisor.
Palmer notation counts outward FROM the midline within each bracketed quadrant, using 1-8 for permanent teeth (1 = central incisor, 3 = canine, 6 = first molar, 8 = third molar) and A-E for primary teeth (A = central incisor, E = second molar). The Universal system instead runs continuously through the whole mouth beginning at the maxillary right, so its A is the maxillary right second primary molar; the same letter therefore means opposite ends of the quadrant in the two systems.
Source: Zsigmondy-Palmer notation (quadrant brackets, 1-8 and A-E from the midline) vs. ADA Universal Tooth Designation SystemReport a problem with this question
5. A referral arrives from a clinic that uses the FDI (ISO) two-digit system. The tooth in question is the permanent mandibular right first molar, which the practice charts as #30. What is its FDI designation and how is it spoken?
- A.16, spoken "sixteen"
- B.44, spoken "forty-four"
- C.36, spoken "thirty-six"
- D.46, spoken "four-six"✓ Answer
In the FDI/ISO two-digit system the first digit names the quadrant (1 = permanent maxillary right, 2 = permanent maxillary left, 3 = permanent mandibular left, 4 = permanent mandibular right) and the second digit counts the tooth 1-8 from the midline, so the mandibular right first molar is quadrant 4, tooth 6 = 46. The digits are always read separately as "four-six" because reading it as forty-six invites confusion with a Universal number.
Source: ISO 3950 / FDI two-digit tooth designation systemReport a problem with this question
6. A parent asks which permanent teeth will take the place of her child's primary molars. What is the accurate answer?
- A.The permanent first and second molars replace the primary first and second molars, one for one, in the same positions.
- B.Primary molars are not replaced; they are retained for life unless caries requires their removal.
- C.The permanent premolars replace the primary molars; the 12 permanent molars have no primary predecessors and erupt distal to the primary dentition.✓ Answer
- D.The permanent canines drift distally to replace the primary molars, and the premolars replace the primary canines.
The primary dentition of 20 teeth contains five teeth per quadrant (central incisor, lateral incisor, canine, first molar, second molar) and has no premolars, so the primary molars are succeeded by the permanent premolars in the same positions. Only 20 permanent teeth are succedaneous; the 12 permanent molars are accessional, erupting behind the primary teeth into new bone, which is why the primary second molar acts as a natural space maintainer for the permanent first molar.
Source: DANB AMP Exam Outline, Domain II (primary dentition and succedaneous teeth); standard dental anatomy referencesReport a problem with this question
7. During an infant oral health visit, which primary teeth are normally the first to erupt, and in what approximate age range?
- A.The mandibular first molars, about 14-18 months
- B.The maxillary canines, about 16-22 months
- C.The maxillary central incisors, about 8-12 months
- D.The mandibular central incisors, about 6-10 months✓ Answer
Primary eruption proceeds from anterior to posterior and generally begins with the mandibular central incisors in the range of about 6-10 months, followed by the maxillary centrals at roughly 8-12 months; the maxillary second primary molars are last at about 25-33 months, completing the 20-tooth primary dentition near age three. Eruption is reported as a range rather than a fixed age because individual timing varies widely while the sequence stays consistent.
Source: ADA MouthHealthy primary tooth eruption chart (eruption ranges by tooth)Report a problem with this question
8. An extracted permanent tooth shows four functional cusps, a small fifth cusp on the mesiolingual cusp, a prominent ridge running obliquely across the occlusal table from the mesiolingual cusp to the distobuccal cusp, and three roots. Which tooth is it?
- A.Maxillary first molar✓ Answer
- B.Mandibular second molar
- C.Mandibular first molar
- D.Maxillary second premolar
Three roots (mesiobuccal, distobuccal and lingual) identify the tooth as maxillary, since mandibular molars have only two roots, and the oblique ridge joining the mesiolingual and distobuccal cusps together with the fifth cusp of Carabelli on the mesiolingual cusp is characteristic of the maxillary first molar. It is the largest tooth by volume in the permanent dentition and one of the "six-year molars" (#3 and #14).
Source: Dental anatomy of the permanent maxillary first molar (oblique ridge, cusp of Carabelli, three roots); DANB AMP Domain IIReport a problem with this question
9. A permanent molar recovered after extraction has five cusps, three of them buccal and two lingual, and two roots, one mesial and one distal. Which tooth best fits this description?
- A.Mandibular first molar✓ Answer
- B.Mandibular second molar
- C.Maxillary first molar
- D.Mandibular second premolar
Two roots place the tooth in the mandibular arch, and the five-cusp pattern with an extra distal cusp on the buccal side is the classic mandibular first molar, the largest mandibular tooth; the mandibular second molar typically shows four cusps in a cross or "plus" groove pattern. Cusp count plus root count is the fastest way to discriminate between adjacent molars, since both mandibular molars share the same two-root form.
Source: Dental anatomy of the permanent mandibular first and second molars (cusp and root counts); DANB AMP Domain IIReport a problem with this question
10. Which permanent tooth is characterized by two cusps, a mesial developmental depression on the crown extending onto the root, and most often two roots, one buccal and one lingual?
- A.Mandibular first premolar
- B.Maxillary second premolar
- C.Mandibular second premolar
- D.Maxillary first premolar✓ Answer
The maxillary first premolar is the usual two-rooted premolar, splitting into a buccal and a lingual root, and its mesial developmental depression is a distinguishing feature; the maxillary second premolar normally has a single root. Among mandibular premolars the first has a large buccal cusp with a small nonfunctional lingual cusp on one root, and the second commonly has three cusps (one buccal, two lingual) on one root, so root and cusp counts separate all four.
Source: Dental anatomy of the permanent premolars (root and cusp morphology); DANB AMP Domain IIReport a problem with this question
11. At the orthodontic evaluation the assistant records that the mesiobuccal cusp of the permanent maxillary first molar occludes mesial to the buccal groove of the permanent mandibular first molar, the mandible is retruded, and the maxillary central incisors are proclined with 8 mm of overjet. How is this occlusion classified?
- A.Angle Class II, Division 2 (distoclusion)
- B.Angle Class II, Division 1 (distoclusion)✓ Answer
- C.Angle Class III (mesioclusion)
- D.Angle Class I (neutroclusion)
Angle's classification is defined by where the mesiobuccal cusp of the maxillary first molar meets the buccal groove of the mandibular first molar: in the buccal groove is Class I, mesial to it means the mandible sits distally (Class II, distoclusion) and distal to it means the mandible sits mesially (Class III, mesioclusion). Class II is subdivided by the incisors, with Division 1 showing proclined maxillary incisors and excessive overjet and Division 2 showing retroclined maxillary central incisors with a deep overbite; overjet is horizontal overlap while overbite is vertical.
Source: Angle's classification of occlusion (molar relationship: maxillary first molar mesiobuccal cusp to mandibular first molar buccal groove); DANB AMP Domain IIReport a problem with this question
12. The dentist finds caries on the distal surface of the maxillary left lateral incisor, and the lesion involves the incisal angle. Under G.V. Black's cavity classification, how should this be recorded?
- A.Class VI
- B.Class V
- C.Class III
- D.Class IV✓ Answer
Class III and Class IV both involve proximal (mesial or distal) surfaces of anterior teeth and differ only in whether the incisal angle is involved: Class III spares it, Class IV includes it, so this lesion is Class IV. For contrast, Class I is pit-and-fissure, Class II is proximal surfaces of posterior teeth, Class V is the cervical third of any facial or lingual surface, and Class VI is a worn incisal edge or cusp tip.
Source: G.V. Black cavity classification, Classes I-VI (Class IV = proximal surface of an anterior tooth including the incisal angle)Report a problem with this question
13. Which statement about the calcified tissues of the tooth is accurate?
- A.Enamel, produced by ameloblasts that are lost when the tooth erupts, is the hardest tissue in the body and cannot regenerate, while the underlying dentin is produced by odontoblasts that survive and can add reparative dentin.✓ Answer
- B.Cementum is the hardest calcified tissue of the body and forms the outer covering of the anatomic crown.
- C.Dentin is deposited by ameloblasts and contains no tubules, which is why it is insensitive when exposed.
- D.The pulp is a calcified tissue that remineralizes and rebuilds lost enamel after a fracture.
Enamel is the hardest tissue in the body because it is almost entirely inorganic hydroxyapatite and it is acellular, so once the ameloblasts are lost at eruption no new enamel can be made and lost enamel must be restored artificially. Dentin makes up the bulk of the tooth, is formed by odontoblasts whose processes occupy the dentinal tubules that transmit sensitivity, and those odontoblasts remain in the pulp and can lay down secondary and reparative dentin; cementum covers the anatomic root and is the softest of the three calcified tissues.
Source: Histology of the dental tissues: enamel (ameloblasts, acellular), dentin (odontoblasts, dentinal tubules), cementum; DANB AMP Domain IIReport a problem with this question
14. While charting the periodontium, the hygienist calls out a 5 mm probing depth at the distobuccal of tooth #30 with 3 mm of gingival recession, so the free gingival margin sits 3 mm apical to the cementoenamel junction. What clinical attachment loss should be recorded at that site?
- A.3 mm
- B.8 mm✓ Answer
- C.2 mm
- D.5 mm
Clinical attachment loss is measured from the cementoenamel junction to the base of the pocket, so when recession has moved the gingival margin apical to the CEJ it is calculated as probing depth plus recession: 5 mm + 3 mm = 8 mm. Probing depth alone understates destruction in a recessed site, which is why six sites per tooth (mesiobuccal, mid-buccal, distobuccal, mesiolingual, mid-lingual, distolingual) are probed and recession is recorded separately; a healthy sulcus measures about 1-3 mm.
Source: American Academy of Periodontology definition of clinical attachment level (probing depth plus recession measured from the CEJ)Report a problem with this question
15. The dentist is about to prepare crowns on the mandibular right first and second molars and asks for the block that will anesthetize those teeth. Which nerve is the target?
- A.The ophthalmic division (V1), by a supraorbital block
- B.The facial nerve (CN VII), which carries sensation from the mandibular teeth
- C.The maxillary division (V2), by a posterior superior alveolar block
- D.The mandibular division (V3), by an inferior alveolar block✓ Answer
Sensation from the mandibular teeth travels in the inferior alveolar nerve, a branch of the mandibular division (V3) of the trigeminal nerve, which runs in the mandibular canal and continues as the mental and incisive branches. The facial nerve (CN VII) is a distractor because it supplies the muscles of facial expression, not dental sensation, and V2 supplies only the maxillary teeth and palate.
Source: Trigeminal nerve (CN V) branches: mandibular division V3 and the inferior alveolar nerve; CN VII supplies muscles of facial expressionReport a problem with this question
16. Anesthesia is needed for the palatal soft tissue lingual to the maxillary central and lateral incisors before a soft-tissue procedure. Which nerve is anesthetized, and at which landmark is the injection given?
- A.The greater palatine nerve, at the greater palatine foramen near the second molar
- B.The nasopalatine nerve, at the incisive papilla just lingual to the central incisors✓ Answer
- C.The long buccal nerve, in the mucobuccal fold distal to the molars
- D.The lesser palatine nerve, in the soft palate
The nasopalatine nerve, a branch of the maxillary division (V2), emerges through the incisive foramen beneath the incisive papilla and supplies the palatal mucosa of the anterior maxilla from canine to canine, so the papilla is the injection landmark. The greater palatine nerve supplies the posterior hard palate and its palatal rugae region behind the canines, which is why the two palatal injections are chosen by how far anterior the working field lies.
Source: Maxillary division (V2) branches: nasopalatine nerve at the incisive foramen/papilla; greater palatine nerve to the posterior hard palateReport a problem with this question
17. While retracting the cheek, the assistant sees the orifice of the parotid duct (Stensen's duct). Where does that duct normally open?
- A.On the buccal mucosa opposite the maxillary first molar
- B.At the sublingual caruncle in the anterior floor of the mouth
- C.On the buccal mucosa opposite the maxillary second molar✓ Answer
- D.On the buccal mucosa opposite the mandibular second molar
The parotid gland, the largest salivary gland and the one producing serous saliva, drains through Stensen's duct, which crosses the masseter and pierces the buccinator to open on the buccal mucosa opposite the maxillary second molar. Knowing that landmark matters clinically because the papilla can be traumatized by a rubber dam clamp, matrix band or high-volume evacuator tip placed too far posteriorly on the cheek.
Source: Anatomy of the major salivary glands: parotid gland and Stensen's duct orifice opposite the maxillary second molarReport a problem with this question
18. A patient has a stone obstructing the duct that opens at the sublingual caruncle in the anterior floor of the mouth. Which gland and duct are involved?
- A.The parotid gland, draining through Stensen's duct
- B.The submandibular gland, draining through Wharton's duct✓ Answer
- C.The sublingual gland, draining through the ducts of Rivinus along the floor of the mouth
- D.The parotid gland, draining through Wharton's duct behind the maxillary tuberosity
The submandibular gland empties through Wharton's duct, which runs forward beneath the tongue and opens at the sublingual caruncle beside the lingual frenum, and it contributes the greatest volume of saliva of the three major glands. The parotid drains far posteriorly through Stensen's duct on the cheek, and the sublingual gland drains through Bartholin's duct and the small ducts of Rivinus along the floor of the mouth, so the caruncle location identifies the submandibular gland.
Source: Anatomy of the major salivary glands: submandibular gland and Wharton's duct opening at the sublingual caruncleReport a problem with this question
19. Which muscle of mastication protrudes the mandible and assists in depressing it to open the mouth, rather than elevating it to close?
- A.Lateral pterygoid✓ Answer
- B.Masseter
- C.Temporalis
- D.Medial pterygoid
Of the four muscles of mastication, the masseter (the most powerful elevator), the temporalis and the medial pterygoid all close the jaw, while the lateral pterygoid pulls the condyle and articular disc forward down the articular eminence, producing protrusion and assisting opening. All four are innervated by the mandibular division (V3) of the trigeminal nerve, which is why V3 anesthesia and trigeminal disorders affect chewing.
Source: Muscles of mastication and their actions; all innervated by the mandibular division (V3) of CN VReport a problem with this question
20. A patient reports clicking and limited opening, and the assistant records findings for the temporomandibular joint. Which description of that joint is correct?
- A.A fibrous immovable joint uniting the mandible to the maxilla
- B.A ball-and-socket joint between the mandibular condyle and the zygomatic arch
- C.A ginglymoarthrodial joint between the mandibular condyle and the glenoid (mandibular) fossa of the temporal bone, with an articular disc between the bony surfaces✓ Answer
- D.A hinge-only joint that permits rotation but no forward translation of the condyle
The temporomandibular joint is ginglymoarthrodial, meaning it both rotates like a hinge in early opening and glides (translates) as the condyle and disc move forward along the articular eminence during wide opening and protrusion, with the articular disc cushioning the condyle against the temporal bone. The mandible is the only movable bone of the skull, and disc-condyle incoordination during that translation is the usual source of the clicking a patient reports.
Source: Anatomy of the temporomandibular joint: mandibular condyle, glenoid (mandibular) fossa of the temporal bone, articular disc, ginglymoarthrodial movementReport a problem with this question
21. A patient with a current upper respiratory infection reports a dull ache in several maxillary posterior teeth on one side. All of those teeth test vital, none are carious or restored, and no periodontal defect is found. Which anatomical structure most likely explains the symptom?
- A.The maxillary sinus✓ Answer
- B.The frontal sinus
- C.The mandibular canal
- D.The sublingual space
The maxillary sinus is the largest paranasal sinus and its floor lies directly above the roots of the maxillary premolars and molars, often separated by only a thin plate of bone, so sinus inflammation refers pain to several adjacent posterior teeth at once rather than to a single tooth. That same proximity explains why root apices can be displaced into the sinus or an oroantral communication created during a maxillary posterior extraction.
Source: Anatomy of the paranasal sinuses: maxillary sinus relationship to maxillary posterior root apicesReport a problem with this question
22. A patient's chart shows generalized 6 mm probing depths, bleeding on probing, furcation involvement on the first molars and radiographic bone loss. To which recognized dental specialty is this patient most appropriately referred?
- A.Orthodontist
- B.Endodontist
- C.Periodontist✓ Answer
- D.Prosthodontist
Specialty referral follows the tissue that is diseased: a periodontist treats the supporting structures of the teeth, the gingiva, periodontal ligament, cementum and alveolar bone, which is exactly what pocketing, furcation involvement and bone loss describe. An endodontist treats disease of the pulp and periapical tissues, a prosthodontist restores and replaces teeth with fixed and removable prostheses, and an orthodontist corrects tooth position and occlusal relationships.
Source: National Commission on Recognition of Dental Specialties and Certifying Boards: scope of periodontics (supporting structures of the teeth)Report a problem with this question

Practice questions based on the DANB Radiation Health and Safety (RHS), Infection Control (ICE), and General Chairside Assisting (GC) content outlines, CDC dental infection-prevention guidance, the OSHA Bloodborne Pathogens Standard, and ADA/FDA radiographic selection criteria. DANB, CDA, RHS, ICE, and GC are marks of the Dental Assisting National Board; this site is not affiliated with or endorsed by DANB. The duties a dental assistant may legally perform — and any radiography permit or certification required — are set by your own state dental board. Confirm current requirements with that board and with DANB before testing. About the DANB exams →

1. The dentist dictates, "existing amalgam, mesio-occluso-distal, permanent mandibular right first molar." Using the ADA Universal Numbering System and standard surface abbreviations, how should the assistant enter this in the chart?

2. A hygienist asks the assistant to chart a sealant placed on the patient's maxillary LEFT first permanent molar. Because the chart is laid out from the operator's viewpoint, the patient's right side appears on the left of the chart form. Which Universal number belongs in the entry?

3. A four-year-old needs a restoration on the primary tooth occupying the position where permanent tooth #9 will eventually erupt. Under the ADA Universal system for the primary dentition, which letter should the assistant chart?

4. A new assistant trained on Palmer notation is confused because the letter A appears in both Palmer and Universal charting. Which statement correctly resolves the conflict?

5. A referral arrives from a clinic that uses the FDI (ISO) two-digit system. The tooth in question is the permanent mandibular right first molar, which the practice charts as #30. What is its FDI designation and how is it spoken?

6. A parent asks which permanent teeth will take the place of her child's primary molars. What is the accurate answer?

7. During an infant oral health visit, which primary teeth are normally the first to erupt, and in what approximate age range?

8. An extracted permanent tooth shows four functional cusps, a small fifth cusp on the mesiolingual cusp, a prominent ridge running obliquely across the occlusal table from the mesiolingual cusp to the distobuccal cusp, and three roots. Which tooth is it?

9. A permanent molar recovered after extraction has five cusps, three of them buccal and two lingual, and two roots, one mesial and one distal. Which tooth best fits this description?

10. Which permanent tooth is characterized by two cusps, a mesial developmental depression on the crown extending onto the root, and most often two roots, one buccal and one lingual?

12. The dentist finds caries on the distal surface of the maxillary left lateral incisor, and the lesion involves the incisal angle. Under G.V. Black's cavity classification, how should this be recorded?

13. Which statement about the calcified tissues of the tooth is accurate?

14. While charting the periodontium, the hygienist calls out a 5 mm probing depth at the distobuccal of tooth #30 with 3 mm of gingival recession, so the free gingival margin sits 3 mm apical to the cementoenamel junction. What clinical attachment loss should be recorded at that site?

15. The dentist is about to prepare crowns on the mandibular right first and second molars and asks for the block that will anesthetize those teeth. Which nerve is the target?

16. Anesthesia is needed for the palatal soft tissue lingual to the maxillary central and lateral incisors before a soft-tissue procedure. Which nerve is anesthetized, and at which landmark is the injection given?

17. While retracting the cheek, the assistant sees the orifice of the parotid duct (Stensen's duct). Where does that duct normally open?

18. A patient has a stone obstructing the duct that opens at the sublingual caruncle in the anterior floor of the mouth. Which gland and duct are involved?

19. Which muscle of mastication protrudes the mandible and assists in depressing it to open the mouth, rather than elevating it to close?

20. A patient reports clicking and limited opening, and the assistant records findings for the temporomandibular joint. Which description of that joint is correct?

21. A patient with a current upper respiratory infection reports a dull ache in several maxillary posterior teeth on one side. All of those teeth test vital, none are carious or restored, and no periodontal defect is found. Which anatomical structure most likely explains the symptom?

22. A patient's chart shows generalized 6 mm probing depths, bleeding on probing, furcation involvement on the first molars and radiographic bone loss. To which recognized dental specialty is this patient most appropriately referred?