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BCO practice questions

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Question 1Diagnosis and Treatment Planning

A patient's manifest astigmatism is measured as 1.50 D. During subjective refinement, the patient reports clearer vision when the correcting minus cylinder axis is rotated from 180 to 175 degrees. What is the most appropriate next step?

  1. Add plus sphere power until acuity stabilizes
  2. Return the axis to 180 degrees and increase cylinder power
  3. Reduce cylinder power and recheck the axis
  4. Rotate the axis further toward 170 degrees and reassess acuity Correct answer.

Explanation

Axis refinement follows the direction that improved acuity, so the examiner continues rotating in the same direction until acuity no longer improves or begins to decline. Power changes should not be made until the axis is settled, because cylinder power interacts with axis position.

Question 2Diagnosis and Treatment Planning

Which finding during case history most strongly suggests that a patient's reduced vision is caused by an uncorrected refractive error rather than ocular disease?

  1. Gradual bilateral blur that improves with squinting Correct answer.
  2. Pain on eye movement with photophobia
  3. Flashes of light followed by a curtain over the field
  4. Sudden monocular loss with a visual field defect

Explanation

Slowly progressive, symmetric blur that improves with squinting or pinhole is the classic pattern of ametropia. Sudden unilateral loss, pain, and photopsia with field loss point toward retinal or neurologic disease and require urgent evaluation.

Question 3Diagnosis and Treatment Planning

A 45-year-old emmetrope reports needing to hold reading material farther away and experiencing blur at near. What is the most likely diagnosis?

  1. Latent hyperopia
  2. Incipient presbyopia Correct answer.
  3. Convergence insufficiency
  4. Accommodative esotropia

Explanation

Around the mid-forties the amplitude of accommodation declines enough to blur near work in an emmetrope, which is presbyopia. The complaint of pushing reading material farther away is the typical adaptive behavior.

Question 4Diagnosis and Treatment Planning

A patient with a spherical equivalent of -4.00 D reports good distance vision with spectacles but constant blur at near despite a +1.50 D add. Which measurement should be obtained first to guide the near prescription?

  1. Pupil size in dim illumination
  2. Contrast sensitivity testing
  3. Amplitude of accommodation and near point of convergence Correct answer.
  4. Corneal topography

Explanation

When a near add fails to relieve symptoms, the examiner must establish how much accommodation is available and whether convergence is adequate. Amplitude of accommodation and near point of convergence directly guide add power and binocular treatment.

Question 5Diagnosis and Treatment Planning

During cover testing, a patient's left eye moves outward to take up fixation when the right eye is covered, and the right eye moves outward when the left eye is covered. Which diagnosis fits this pattern?

  1. Esotropia
  2. Left hypertropia
  3. Exotropia Correct answer.
  4. Right hypertropia

Explanation

A deviation in which the covered eye moves outward to fix indicates an exodeviation, because the eye must turn temporally to regain the target. Alternating outward movement on either cover indicates an alternating exotropia.

Question 6Diagnosis and Treatment Planning

A patient reports intermittent diplopia at distance only, with normal near binocular vision. Which diagnosis should be considered first?

  1. Intermittent distance exotropia Correct answer.
  2. Convergence insufficiency
  3. Accommodative esotropia
  4. Monocular diplopia from cataract

Explanation

Diplopia that occurs only at distance with comfortable near alignment suggests a divergence insufficiency or intermittent distance exotropia. Accommodative esotropia and convergence insufficiency produce problems at near rather than distance.

Question 7Diagnosis and Treatment Planning

Which test result best confirms that a patient's reduced visual acuity is due to a refractive cause rather than amblyopia or media opacity?

  1. Normal color vision plates
  2. Normal confrontation fields
  3. Improvement with pinhole or stenopeic slit Correct answer.
  4. Equal pupil responses to light

Explanation

A pinhole or stenopeic slit reduces the blur circle from uncorrected refractive error, so acuity improves when ametropia is the cause. Amblyopia and dense media opacity usually show little or no pinhole improvement.

Question 8Diagnosis and Treatment Planning

A patient's retinoscopy at 50 cm with a working distance lens yields +2.00 D in the right eye. What is the net refractive error?

  1. 0.00 D Correct answer.
  2. -2.00 D
  3. +4.00 D
  4. +2.00 D

Explanation

At a 50 cm working distance, 2.00 D must be subtracted from the retinoscopy finding to remove the working distance effect. Subtracting 2.00 D from +2.00 D leaves a net refraction of plano.

Question 9Diagnosis and Treatment Planning

Which patient history element most increases suspicion of keratoconus and should prompt corneal topography before contact lens fitting?

  1. Long-standing intermittent exotropia
  2. Presbyopia beginning at age 44
  3. Stable hyperopia since childhood
  4. Progressive myopic astigmatism with frequent prescription changes Correct answer.

Explanation

Keratoconus commonly presents with increasing myopia and irregular astigmatism that requires frequent prescription changes. Topography should be obtained before fitting lenses because contact lenses can mask or alter corneal shape.

Question 10Diagnosis and Treatment Planning

A diabetic patient reports fluctuating vision throughout the day. Which explanation best accounts for this symptom?

  1. Bilateral optic neuropathy
  2. Progressive nuclear sclerosis
  3. Intermittent angle closure
  4. Osmotic variation in lens hydration from fluctuating glucose Correct answer.

Explanation

Fluctuating blood glucose alters lens hydration osmotically, producing transient refractive shifts and variable blur. This pattern is characteristic of poorly controlled diabetes and should prompt coordination with the patient's physician.

Question 11Diagnosis and Treatment Planning

Which preoperative finding is most important to document before recommending refractive surgery in a patient with a stable prescription?

  1. Corneal thickness and topographic pattern Correct answer.
  2. Stereopsis threshold
  3. Tear film breakup time alone
  4. Color vision testing

Explanation

Corneal thickness and topography determine whether enough tissue remains after ablation and whether ectasia risk is present. These measurements are central to candidacy and safety planning for refractive surgery.

Question 12Diagnosis and Treatment Planning

A patient with a known allergy to preserved saline needs a diagnostic contact lens trial. Which lens selection is most appropriate?

  1. Reusable hydrogel lens stored in multipurpose solution
  2. Daily disposable lens with multipurpose solution avoided Correct answer.
  3. Rigid gas permeable lens with preserved wetting drops
  4. Scleral lens with preserved saline filling

Explanation

A daily disposable lens minimizes exposure to care solutions and is the safest choice when preservative sensitivity is documented. Reusable lenses require storage solutions that may reintroduce the offending preservative.

Question 13Diagnosis and Treatment Planning

Which measurement is essential before ordering a rigid gas permeable lens for a patient with high astigmatism?

  1. Keratometry readings and corneal diameter Correct answer.
  2. Anterior chamber depth by gonioscopy
  3. Axial length by ultrasound
  4. Macular thickness by OCT

Explanation

Rigid lens design depends on corneal curvature and diameter to achieve appropriate alignment and power. Keratometry provides the base curve reference, and the diameter guides overall lens size.

Question 14Diagnosis and Treatment Planning

A patient presents with a painful red eye, decreased vision, and a contact lens worn overnight. Which diagnosis must be excluded first?

  1. Pingueculitis
  2. Dry eye syndrome
  3. Microbial keratitis Correct answer.
  4. Simple conjunctivitis

Explanation

Overnight lens wear with pain, redness, and vision loss raises concern for microbial keratitis, which threatens sight and requires urgent corneal evaluation. This presentation should never be managed as routine conjunctivitis.

Question 15Diagnosis and Treatment Planning

A patient with intermittent exotropia shows control that worsens only when tired, with no suppression on testing and good stereoacuity. What is the most reasonable initial management?

  1. Immediate bilateral medial rectus recession
  2. Observation with periodic monitoring of control and stereoacuity Correct answer.
  3. Penalization of the dominant eye
  4. Prism adaptation with full-time patching

Explanation

Well-controlled intermittent exotropia with preserved stereoacuity can be observed, because many patients remain stable for years. Surgery is reserved for deteriorating control, increasing deviation, or declining binocular function.

Question 16Diagnosis and Treatment Planning

Which finding on a cover-uncover test distinguishes a phoria from a tropia?

  1. Deviation increases with near fixation
  2. Deviation disappears with a pinhole
  3. Deviation appears only when fusion is broken by the cover Correct answer.
  4. Deviation is present with both eyes viewing

Explanation

A phoria is a latent deviation that becomes manifest only when the cover interrupts binocular fusion. A tropia is present even with both eyes open and viewing the same target.

Question 17Diagnosis and Treatment Planning

A patient's symptoms of asthenopia occur after prolonged near work and resolve with a plus add at near. Which underlying mechanism is most likely?

  1. Aniseikonia
  2. Accommodative insufficiency Correct answer.
  3. Latent hyperopia
  4. Divergence excess

Explanation

Accommodative insufficiency produces near asthenopia because the patient cannot sustain the required accommodative effort. A plus add reduces the demand and relieves symptoms, supporting the diagnosis.

Question 18Diagnosis and Treatment Planning

Which test is most useful for detecting a small-angle esotropia in a young child with suspected amblyopia?

  1. Tear film breakup time
  2. Amsler grid testing
  3. Hirschberg and Krimsky testing with fixation preference Correct answer.
  4. Contrast sensitivity testing

Explanation

Hirschberg and Krimsky testing estimate the angle of deviation using corneal light reflexes and prism neutralization, which is practical in young children. Fixation preference adds information about amblyopia in preverbal patients.

Question 19Diagnosis and Treatment Planning

A patient with a long-standing unilateral cataract reports diplopia that persists when either eye is covered. What does this finding indicate?

  1. Binocular diplopia
  2. Divergence insufficiency
  3. Internuclear ophthalmoplegia
  4. Monocular diplopia Correct answer.

Explanation

Diplopia that persists with one eye covered is monocular and arises from optical or retinal causes within that eye, such as cataract or irregular astigmatism. Binocular diplopia disappears when either eye is occluded.

Question 20Diagnosis and Treatment Planning

Which patient report most strongly suggests that a new spectacle prescription is causing aniseikonia?

  1. Near vision is blurred only after reading
  2. Objects appear different in size between the two eyes with the new glasses Correct answer.
  3. Distance vision is clear but colors appear dull
  4. Objects appear tilted and distorted at the edges

Explanation

Aniseikonia is a perceived difference in image size between the eyes, often induced by anisometropic spectacle correction. Edge distortion and tilt suggest unwanted prism or lens aberrations rather than size difference.

Question 21Diagnosis and Treatment Planning

A patient with myopia of -8.00 D asks about refractive surgery. Which factor most limits candidacy for corneal laser ablation?

  1. High myopia requiring extensive tissue removal Correct answer.
  2. Blue iris color
  3. Age over 40 years
  4. Mild dry eye symptoms

Explanation

High myopia requires greater central tissue removal, increasing ectasia risk and reducing residual stromal bed thickness. This is a key limiting factor when evaluating laser ablation candidacy.

Question 22Diagnosis and Treatment Planning

A patient with a suspected retinal detachment reports a new temporal visual field defect in the left eye. Which area of the retina is most likely affected?

  1. Temporal retina of the left eye
  2. Nasal retina of the left eye Correct answer.
  3. Superior retina of the right eye
  4. Inferior retina of the right eye

Explanation

Visual field defects are projected opposite to the retinal location, so a temporal field defect corresponds to nasal retinal damage in the same eye. The nasal retina receives light from the temporal field.

Question 23Diagnosis and Treatment Planning

Which clinical finding would most likely prompt referral for a dilated fundus examination before finalizing a new prescription in a patient with floaters?

  1. New onset of numerous floaters with photopsia Correct answer.
  2. Mild blur corrected by a small minus lens
  3. Slight anisometropia of 0.50 D
  4. Long-standing stable floaters without change

Explanation

A sudden increase in floaters with flashes suggests vitreous detachment or retinal tear and requires prompt dilated fundus evaluation. Chronic stable floaters without new symptoms are lower risk.

Question 24Diagnosis and Treatment Planning

A patient with keratoconus is being fitted with rigid gas permeable lenses. Which lens design principle best improves comfort and centration?

  1. A soft toric lens with high cylinder
  2. A smaller diameter with steep central curve
  3. A larger diameter with alignment on the cone apex avoided Correct answer.
  4. A flat lens that touches the cone apex

Explanation

In keratoconus, rigid lenses are designed to align with the midperipheral cornea and avoid bearing on the cone apex. Larger diameters and appropriate peripheral curves improve centration and comfort.

Question 25Diagnosis and Treatment Planning

Which factor most affects the near add power selected for a patient with a strong accommodative convergence to accommodation ratio?

  1. The patient's iris color
  2. The near esophoria present at the working distance Correct answer.
  3. The patient's distance cylinder axis
  4. The corneal curvature

Explanation

A high accommodative convergence to accommodation ratio produces near esophoria, and a plus add reduces accommodative demand and the associated convergence. The add is therefore guided by the near phoria measurement.

Question 26Diagnosis and Treatment Planning

A 62-year-old patient reports gradual painless loss of near vision over two years and now holds reading material at arm's length. Distance acuity is 20/20 unaided and near acuity improves with a plus lens. What is the most likely diagnosis?

  1. Nuclear sclerotic cataract
  2. Posterior capsule opacification
  3. Presbyopia Correct answer.
  4. Accommodative esotropia

Explanation

Gradual, painless decline in near function after about age 40, with preserved distance acuity and improvement with plus lenses at near, is the classic picture of presbyopia from age-related loss of accommodative amplitude. The key discriminator is that a plus add restores near acuity, which indicates an optical rather than a pathological cause.

Question 27Diagnosis and Treatment Planning

During a subjective refraction, a patient accepts -1.00 DS and achieves 20/20. When +0.50 DS is added, acuity remains 20/20. What is the appropriate next step?

  1. Increase minus to -1.50 DS and recheck acuity
  2. Repeat the entire refraction from scratch
  3. Keep -1.00 DS as the final sphere Correct answer.
  4. Add -0.50 DS cylinder instead

Explanation

When acuity is unchanged after adding plus, the patient is at or near the maximum plus (least minus) endpoint, so the original -1.00 DS is retained rather than pushed further in the minus direction. This avoids overminus, which can provoke accommodative fatigue and asthenopia.

Question 28Diagnosis and Treatment Planning

A patient's presenting visual acuity is 20/200 in the right eye with no improvement on pinhole. Which additional finding most strongly suggests the reduced acuity is not simply uncorrected refractive error?

  1. A near acuity of 20/25 with a plus add
  2. A stable acuity over several visits
  3. A relative afferent pupillary defect in the affected eye Correct answer.
  4. A normal red reflex with clear media

Explanation

A relative afferent pupillary defect indicates asymmetric optic nerve or extensive retinal dysfunction and points to an organic cause of vision loss rather than an optical one. Refractive blur does not produce an afferent pupillary defect.

Question 29Diagnosis and Treatment Planning

A patient with a long-standing tropia reports that the double image disappears when one eye is covered. What does this indicate about the origin of the diplopia?

  1. It is cortical and requires neuroimaging
  2. It is monocular and requires ocular media evaluation
  3. It is likely malingering
  4. It is binocular and arises from misalignment of the two eyes Correct answer.

Explanation

Diplopia that resolves with occlusion of either eye is binocular, meaning the two eyes are receiving images that cannot be fused because of misalignment. Binocular diplopia is therefore investigated with a motility and deviation workup rather than a media workup.

Question 30Diagnosis and Treatment Planning

A 9-year-old presents with 20/25 acuity in the right eye and 20/20 in the left with no strabismus. Cover testing is normal and there is no anisometropia. Which diagnosis best fits?

  1. Isoametropic amblyopia
  2. No amblyopia; acuity is within normal limits for age Correct answer.
  3. Anisometropic amblyopia
  4. Strabismic amblyopia

Explanation

Visual acuity of 20/25 in a 9-year-old is within accepted normal limits, and there is no strabismus or anisometropia to support amblyopia. Amblyopia requires a demonstrable amblyogenic factor plus reduced acuity relative to the fellow eye.

Question 31Diagnosis and Treatment Planning

A patient with a suspected carotid-related ocular ischemic process reports transient monocular vision loss. Which history feature is most important to elicit?

  1. Duration and frequency of episodes Correct answer.
  2. Use of artificial tears
  3. Family history of glaucoma
  4. Recent spectacle change

Explanation

Transient monocular vision loss from vascular insufficiency is characterized by brief episodes, often described as a curtain or shade, and the duration and frequency help distinguish it from other causes. This history guides urgency of referral for systemic vascular evaluation.

Question 32Diagnosis and Treatment Planning

A patient with a known esotropia of 20 prism diopters at distance and 25 at near is being planned for prism correction. Which measurement is essential to determine the prism prescription?

  1. Alternating cover test with prism neutralization at both distances Correct answer.
  2. Stereopsis threshold
  3. Fusional vergence amplitudes
  4. Near point of convergence

Explanation

Prism neutralization of the deviation at each fixation distance quantifies the angle to be corrected and confirms the measurement is stable. Fusional reserves and convergence findings inform management but do not determine the prism power.

Question 33Diagnosis and Treatment Planning

A patient with a strong accommodative convergence to accommodation ratio and a high hyperopic prescription reports asthenopia at near. Which approach best addresses the symptoms?

  1. Reduce the hyperopic correction to encourage accommodation
  2. Prescribe a stronger minus distance correction
  3. Prescribe a base-in prism for all viewing distances
  4. Prescribe the full hyperopic correction for constant wear Correct answer.

Explanation

In a high accommodative convergence to accommodation ratio, the near deviation worsens with accommodative effort, so correcting the hyperopia reduces the accommodation needed and lessens the near esodeviation. This is the standard first step before considering add or prism.

Question 34Diagnosis and Treatment Planning

A patient reports glare and halos at night and has a history of high myopia with prior corneal refractive surgery. Which finding would most warrant evaluation for corneal ectasia?

  1. A central flat cornea with regular astigmatism
  2. Normal pachymetry in both eyes
  3. A stable refraction over three years
  4. Irregular astigmatism on topography with inferior steepening Correct answer.

Explanation

Irregular astigmatism with inferior steepening on topography raises concern for ectasia, particularly after refractive surgery in a highly myopic eye. Topographic irregularity is the key screening signal that prompts corneal cross-linking evaluation and referral.

Question 35Diagnosis and Treatment Planning

A patient with a history of angle-closure symptoms is being evaluated for dilation. Which finding most strongly supports avoiding pharmacologic mydriasis?

  1. A deep anterior chamber with an open angle
  2. A family history of myopia
  3. A shallow anterior chamber with a narrow angle on gonioscopy Correct answer.
  4. A history of seasonal allergies

Explanation

A shallow chamber with narrow angles indicates a high risk of angle closure with mydriasis, so dilation should be avoided or performed with caution and appropriate monitoring. Gonioscopic assessment of the angle is the decisive finding.

Question 36Diagnosis and Treatment Planning

A child presents with a new-onset constant esotropia and no prior eye examination. Which step is most appropriate before finalizing a spectacle prescription?

  1. Cycloplegic retinoscopy Correct answer.
  2. Observation for six months without refraction
  3. Immediate prism prescription
  4. Non-cycloplegic autorefraction only

Explanation

Cycloplegic retinoscopy is the standard for uncovering latent hyperopia in children, which can drive accommodative esotropia. Autorefraction alone may underestimate hyperopia and lead to an inadequate prescription.

Question 37Diagnosis and Treatment Planning

A patient reports that a new spectacle prescription causes distortion and a pulling sensation at the edges of the lenses. Which factor most contributes to this symptom?

  1. A change in base curve with high minus power Correct answer.
  2. An increase in cylinder power only
  3. A decrease in pupillary distance
  4. A change in vertex distance

Explanation

High minus lenses with a changed base curve alter peripheral magnification and prismatic effects, producing distortion and spatial swim. The effect is most noticeable when the base curve or lens form changes substantially.

Question 38Diagnosis and Treatment Planning

A patient with a suspected retinal detachment reports a new temporal visual field defect in the left eye. Which retinal area corresponds to this defect?

  1. Nasal retina of the left eye Correct answer.
  2. Macula of the left eye
  3. Superior retina of the right eye
  4. Temporal retina of the left eye

Explanation

Visual field defects are projected opposite to the retinal location, so a temporal field defect in the left eye corresponds to nasal retinal involvement in that eye. This localization guides the urgency and extent of the dilated fundus examination.

Question 39Diagnosis and Treatment Planning

A patient with a history of amblyopia in the left eye is being evaluated for a new prescription. Which finding would most prompt a dilated fundus examination before finalizing the prescription?

  1. A stable refraction over five years
  2. A history of contact lens wear
  3. A new afferent pupillary defect Correct answer.
  4. A normal red reflex

Explanation

A new afferent pupillary defect suggests optic nerve or retinal disease and warrants a dilated fundus examination before attributing the acuity change to refraction. New asymmetric findings in a patient with prior amblyopia should not be assumed to be amblyopic in origin.

Question 40Diagnosis and Treatment Planning

A patient with keratoconus is being fitted with a rigid gas permeable lens and reports poor comfort with a steep, small-diameter lens. Which design change best improves comfort and centration?

  1. Increase the optical zone thickness
  2. Increase the lens power
  3. Increase the base curve radius to flatten the lens Correct answer.
  4. Decrease the overall lens diameter

Explanation

Flattening the base curve reduces excessive apical bearing over the cone, which is a common source of discomfort and decentration in keratoconus. A flatter fit distributes bearing more evenly and improves tolerance.

Question 41Craniofacial Growth and Development

According to the functional matrix theory, which structure is considered the primary determinant of mandibular growth?

  1. The inferior alveolar nerve
  2. The alveolar bone
  3. The condylar cartilage Correct answer.
  4. The mandibular body

Explanation

The functional matrix concept proposes that growth of skeletal units is driven by their associated soft tissues. The condylar cartilage is regarded as a secondary, compensatory growth site responding to the demands of the surrounding functional matrix rather than initiating growth itself.

Question 42Craniofacial Growth and Development

The cephalometric point sella is best described as which of the following?

  1. The midpoint of the entrance to the sella turcica Correct answer.
  2. The tip of the anterior nasal spine
  3. The lowest point of the orbit
  4. The most anterior point of the frontal bone

Explanation

Sella is defined as the geometric center of the sella turcica, the bony depression housing the pituitary gland. It serves as a key reference point in cephalometric analysis because of its relative stability after early childhood.

Question 43Craniofacial Growth and Development

During which period does the greatest percentage of cranial vault growth occur?

  1. Prenatally and in the first few postnatal years Correct answer.
  2. After the third decade of life
  3. During the pubertal growth spurt
  4. In early adulthood

Explanation

Neural tissue and the cranial vault follow a cephalocaudal gradient, growing most rapidly before and shortly after birth. By about age six or seven the brain has reached nearly adult size, so later vault growth is minimal.

Question 44Craniofacial Growth and Development

Which of the following best characterizes the pattern of facial growth described by Scammon's curve for skeletal tissue?

  1. A general or neural pattern Correct answer.
  2. A genital pattern
  3. A neural pattern
  4. A lymphoid pattern

Explanation

Scammon described four growth curves: lymphoid, neural, general (somatic including skeletal), and genital. Skeletal tissue follows the general curve, growing steadily through childhood with a pubertal spurt.

Question 45Craniofacial Growth and Development

The term 'drift' in bone remodeling refers to which process?

  1. Movement of a whole bone through coordinated deposition and resorption Correct answer.
  2. Loss of alveolar bone after tooth extraction
  3. Passive displacement caused by growth of adjacent structures
  4. Sudden fracture of cortical bone

Explanation

Drift is the relocation of a bone or its parts by coupled resorption on one surface and deposition on the opposite surface. It differs from displacement, which is passive movement of a bone as neighboring structures enlarge.

Question 46Craniofacial Growth and Development

A clinician notes that the mandible grows primarily by apposition at the posterior border of the ramus with simultaneous resorption at the anterior border. This observation supports which principle?

  1. Enlargement of the cranial base
  2. Cortical drift of the mandible Correct answer.
  3. Passive displacement of the maxilla
  4. Eruption of the permanent molars

Explanation

The mandible enlarges through surface apposition and resorption that shift the ramus posteriorly, lengthening the body. This coordinated cortical drift allows the arch to accommodate erupting molars while maintaining proportions.

Question 47Craniofacial Growth and Development

Which suture is most closely associated with growth of the midface and is often implicated in maxillary deficiency?

  1. The midpalatal suture Correct answer.
  2. The lambdoid suture
  3. The coronal suture
  4. The squamosal suture

Explanation

The midpalatal suture lies between the two maxillary halves and contributes to transverse growth of the midface. Its premature fusion can produce a constricted maxilla requiring expansion.

Question 48Craniofacial Growth and Development

A cephalometric analysis shows an SNA of 84 degrees and an SNB of 78 degrees. What does the ANB angle indicate?

  1. A skeletal Class III tendency
  2. A normal skeletal relationship
  3. A skeletal Class II tendency Correct answer.
  4. A severe vertical discrepancy

Explanation

ANB is calculated by subtracting SNB from SNA, giving 6 degrees here. An ANB greater than about 4 degrees suggests the maxilla is positioned forward relative to the mandible, indicating a skeletal Class II pattern.

Question 49Craniofacial Growth and Development

The term 'remodeling' as distinguished from 'displacement' in craniofacial growth refers to which of the following?

  1. Movement of a bone as a whole due to adjacent growth
  2. Change in size and shape of a bone by deposition and resorption Correct answer.
  3. Formation of new sutures between bones
  4. Increase in number of osteocytes within bone

Explanation

Remodeling alters a bone's size and shape through localized deposition and resorption. Displacement, by contrast, is the translation of an entire bone caused by growth elsewhere.

Question 50Craniofacial Growth and Development

Which of the following best describes the growth of the maxilla in the transverse dimension during childhood?

  1. It decreases steadily with age
  2. It increases primarily through sutural growth at the midpalatal suture Correct answer.
  3. It grows only after puberty
  4. It remains constant from birth

Explanation

Transverse maxillary growth occurs largely at the midpalatal suture and other circummaxillary sutures. This growth is most active in early childhood and tapers after the pubertal period.