Dental MCQ
Choosing the appliance · Orthodontics · INBDE Patient Cases

Fixed, Removable & Functional Appliances INBDE Patient Cases

By Dr. Isaac Sun, DDS

7 ADA INBDE-format patient cases on fixed, removable & functional appliances. Each case is a shared patient box (chief complaint, history, medications, allergies, exam) followed by linked multiple-choice questions with full distractor explanations. Practice the way the real exam is structured.

7 patient cases35 linked questionsADA INBDE formatFull distractor explanations

Seven ADA INBDE-format patient cases on orthodontic appliances: Twin Block functional appliance in a growing Class II Division 1 patient (with Herbst as a fixed alternative), cervical vs high-pull headgear with vertical pattern (FMA) driving the choice, rapid maxillary expansion with a Hyrax appliance in a growing patient and SARPE in adults whose midpalatal suture has fused, reverse-pull facemask for growing Class III with maxillary deficiency (combined with palatal expansion), clear aligners with composite attachments and IPR (with strengths in mild crowding and limits for big rotations, extrusion, torque, and complex skeletal cases), white spot lesions around fixed appliances with topical fluoride and CPP-ACP prevention, and hygiene around fixed lower lingual retainers with interproximal hygiene aids. Topics include the straight-wire appliance, self-ligating brackets, NiTi/TMA/stainless steel archwire sequence, removable Hawley appliances, functional appliances, headgear types, clear aligners, and palatal expansion (Hyrax and slow).

Case Coverage Map
What each case is testing
Twin Block in a growing Class II Div 1:
Twin Block design, pubertal-spurt timing, Herbst alternative, and the comprehensive fixed/aligner finishing phase.
Cervical vs high-pull headgear in Class II:
Vertical pattern decides: low-pull (cervical) extrudes (low-angle/deep-bite); high-pull avoids extrusion (high-angle/open-bite); compliance ~12-14 h/day.
RPE/Hyrax for maxillary constriction with crossbite:
Hyrax activation rate, midline diastema as a positive sign, and SARPE in adults whose suture has fused.
Reverse-pull facemask for growing Class III:
Facemask for growing maxillary deficiency, combination with palatal expansion, optimal age window, and orthognathic surgery in non-growing severe cases.
Clear aligners: indications and limitations:
Aligner design (trays + attachments + IPR), strengths in mild crowding/tipping, known limits (big rotations, extrusion, torque, complex Class II/III), and refinement.
Fixed appliances and white spot lesions:
Decalcification mechanism, prevention with topical fluoride and CPP-ACP, deband consideration if hygiene fails, and post-deband management options.
Hygiene around a fixed lower lingual retainer:
Interproximal hygiene aids for fixed retainers, Hawley vs Essix differences, broken-wire relapse risk, and case-specific retainer choice.
Patient case: Twin Block in a growing Class II Div 1
0 of 5 answered, 0 correct
Patient
Male, 11 years old
Chief Complaint
Mandibular retrognathia with large overjet; family asks about a Twin Block.
Background and/or Patient History
  • Skeletal Class II with mandibular retrognathia (ANB 6°, normal FMA)
  • Pubertal growth spurt approaching per CVM staging
  • Twin Block planned
Allergies
NKDA
Medications
  • None
Current Findings
  • Growing Class II Div 1 with mandibular deficiency
  • Functional appliance candidate
  1. Question 1
    Easy
    The Twin Block appliance is best characterized as a:
  2. Question 2
    Moderate
    Twin Block works best when:
  3. Question 3
    Moderate
    An alternative fixed (non-removable) functional appliance with continuous mandibular advancement is:
  4. Question 4
    Moderate
    After successful Twin Block therapy, the next phase is usually:
  5. Question 5
    Easy
    The teaching point is that functional appliances:

Reset this case?

This clears your answers for this patient case only.

Patient case: Cervical vs high-pull headgear in Class II
0 of 5 answered, 0 correct
Patient
Female, 12 years old
Chief Complaint
Class II molar with mild overjet; growing; high-angle vertical pattern.
Background and/or Patient History
  • Class II Div 1 with FMA 33° (high-angle)
  • Headgear discussed as adjunct mechanics
  • Question of cervical vs high-pull
Allergies
NKDA
Medications
  • None
Current Findings
  • High-angle Class II growing patient
  • Headgear choice driven by vertical pattern
  1. Question 1
    Moderate
    Cervical (low-pull) headgear primarily:
  2. Question 2
    Hard
    In a HIGH-angle Class II patient, the preferred headgear is:
  3. Question 3
    Moderate
    Cervical headgear suits:
  4. Question 4
    Moderate
    Headgear depends heavily on:
  5. Question 5
    Easy
    The teaching point is that the vertical pattern (FMA, mandibular plane angle):

Reset this case?

This clears your answers for this patient case only.

Patient case: RPE/Hyrax for maxillary constriction with crossbite
0 of 5 answered, 0 correct
Patient
Female, 9 years old
Chief Complaint
Bilateral posterior crossbite with a narrow upper arch.
Background and/or Patient History
  • Bilateral maxillary constriction in a growing child
  • Bilateral posterior crossbite
  • Plan for rapid maxillary expansion with a Hyrax appliance
Allergies
NKDA
Medications
  • None
Current Findings
  • Growing child with maxillary constriction
  • RPE/Hyrax candidate
  1. Question 1
    Moderate
    RPE (Hyrax) opens the:
  2. Question 2
    Moderate
    Activation of the Hyrax screw is typically:
  3. Question 3
    Moderate
    A midline diastema during RPE activation:
  4. Question 4
    Moderate
    In an ADULT whose midpalatal suture has fused, skeletal expansion typically requires:
  5. Question 5
    Easy
    The teaching point is that palatal expansion in growing vs adult patients:

Reset this case?

This clears your answers for this patient case only.

Patient case: Reverse-pull facemask for growing Class III
0 of 5 answered, 0 correct
Patient
Male, 9 years old
Chief Complaint
Class III with maxillary deficiency; family asks about early treatment.
Background and/or Patient History
  • Skeletal Class III with maxillary deficiency
  • Anterior crossbite
  • Growing patient (within facemask window)
Allergies
NKDA
Medications
  • None
Current Findings
  • Growing skeletal Class III patient
  • Facemask candidate
  1. Question 1
    Moderate
    Reverse-pull (facemask) therapy:
  2. Question 2
    Hard
    Facemask is often combined with:
  3. Question 3
    Moderate
    Facemask works best when:
  4. Question 4
    Moderate
    Severe non-growing Class III is often treated with:
  5. Question 5
    Easy
    The teaching point is that growth status:

Reset this case?

This clears your answers for this patient case only.

Patient case: Clear aligners: indications and limitations
0 of 5 answered, 0 correct
Patient
Female, 24 years old
Chief Complaint
Asks about clear aligners for mild lower crowding.
Background and/or Patient History
  • Mild lower anterior crowding (about 3 mm)
  • Class I molar and canine
  • Aesthetic concerns; preference for aligners
Allergies
NKDA
Medications
  • None
Current Findings
  • Healthy adult with mild crowding suitable for aligners
  1. Question 1
    Easy
    Clear aligners deliver tooth movement through:
  2. Question 2
    Hard
    Aligners are LIMITED for:
  3. Question 3
    Moderate
    Compliance with aligners means wearing them about:
  4. Question 4
    Moderate
    If a planned movement does not track at the end of an initial aligner series, the next step is:
  5. Question 5
    Easy
    The teaching point is that aligners are:

Reset this case?

This clears your answers for this patient case only.

Patient case: Fixed appliances and white spot lesions
0 of 5 answered, 0 correct
Patient
Male, 14 years old
Chief Complaint
Chalky white spots visible around brackets at the 6-month progress visit.
Background and/or Patient History
  • Comprehensive fixed appliances for 6 months
  • Suboptimal oral hygiene
  • Chalky white opacities at cervical and labial bracket margins
Allergies
NKDA
Medications
  • None
Current Findings
  • Early white spot lesions (decalcification) around brackets
  1. Question 1
    Moderate
    White spot lesions around brackets are:
  2. Question 2
    Moderate
    Prevention and management include:
  3. Question 3
    Hard
    If hygiene cannot be improved during a long treatment, the dentist should:
  4. Question 4
    Moderate
    After deband, residual white spot lesions may be addressed with:
  5. Question 5
    Easy
    The teaching point is that fixed appliances:

Reset this case?

This clears your answers for this patient case only.

Patient case: Hygiene around a fixed lower lingual retainer
0 of 5 answered, 0 correct
Patient
Female, 19 years old
Chief Complaint
Post-treatment fixed lingual retainer placed on the lower 3-3; patient asks about cleaning.
Background and/or Patient History
  • Comprehensive orthodontic treatment completed
  • Bonded lingual 3-3 wire on the lower anterior teeth
  • Healthy patient
Allergies
NKDA
Medications
  • None
Current Findings
  • Fixed lower lingual retainer hygiene counseling
  1. Question 1
    Moderate
    Fixed lower lingual retainers (3-3 or 4-4):
  2. Question 2
    Easy
    An alternative removable retainer is:
  3. Question 3
    Moderate
    Hawley retainers differ from Essix in that:
  4. Question 4
    Moderate
    If a bonded retainer wire breaks at one end and is not noticed for months, the consequence is:
  5. Question 5
    Easy
    The teaching point is that retainer choice is:

Reset this case?

This clears your answers for this patient case only.

Keep studying
Fixed, Removable & Functional Appliances core recall

Refresh the anatomy facts these cases depend on: nerve numbers, foramina, functions, and lesion findings.

← Back to Fixed, Removable & Functional Appliances