6 - Growth and Development

Question 1

What do you need for diagnostic records for orthodontics?

Answer 1

1. Dental study models
2. 8 series photographic collage
3. Complete intra-oral radiographs
4. Cephalometric radiograph including tracing
5. Anterior-posterior radiograph when indicated (for example, when there is a possible facial or occlusal asymmetry)

Some adjustments in this standard will more than likely be forthcoming, with the use of CBCT becoming more commonplace.

Question 2

What are common orthodontic treatment risks to be covered when getting consent?

Answer 2

1. Caries
2. Root resorption
3. Periodontal disease
4. Necrotic pulp
5. Discomfort
6. Trauma
7. TMD considerations
8. Impacted teeth
9. Length of treatment
10. Prognosis
11. Relapse

Question 3

What are the three basic components of a comprehensive orthodontic assessment for a patient?

Answer 3

1. Patient questionnaire
2. Examination (oral health, function, and facial proportions)
3. Diagnostic records

Question 4

Do you have to have cephalometric evaluation for diagnostic records for orthodontic patients?

Answer 4

No. Depending on the severity of the patient’s problem, certain orthodontic records may not be necessary.

Question 5

How would CBCT influence the way orthodontic assessments have been done in the past?

Answer 5

CBCT may eliminate the need to make separate dental study models, intra-oral radiographs and cephalometric radiographs bc all three of these can be captured in the 3D CBCT image.

Question 6

What four broad areas of treatment need to be coveted during the process of informed consent?

Answer 6

1. Type of treatment to be rendered
2. Risks
3. Benefits
4. Alternatives to the treatment

Question 7

What are the alternatives to extraction and distal shoe placement?

Answer 7

1. Aggressive pulpectomy of the primary second molar
2. Extraction and no space management and permit the permanent first molar to drift mesially and impact the second premolars
3. Extraction and use of a removable acrylic pressure appliance that would guide the first permanent molars via pressure and without penetrating the alveolar mucosa

Question 8

What angulation is usually built into the distal shoe blades from an occlusal to gingival direction and why?

Answer 8

Angles mesially to help prevent the permanent first molar from getting impacted under the distal shoe blade.

Question 9

When should bilateral space maintainer be placed on the permanent first molar?

Answer 9

Once the first permanent molars are erupted far enough for banding.

Question 10

What space maintainers are used for space maintenance of the mixed dentition?

Answer 10

For unilateral loss: band and loop spacer

For bilateral loss prior to eruption of the permanent incisors: bilateral band and loop spacers (concerns about the anterior portion of the lower lingual arch wire precludes consideration of this appliance until the incisors erupt)

For bilateral loss after eruption of the permanent incisors: lower lingual arch or acrylic partial denture

Question 11

What is the leeway space?

Answer 11

The extra space between the permanent premolars and canines compared to the primary molars and canines.

Question 12

What is the Tanaka Johnston Analysis?

Answer 12

1. Divide the width of the lower permanent incisors in half.
2. To this number, add 10.5mm for the lower buccal segment; add 11mm for the upper buccal segment.
3. Subtract the number calculated above from the combined widths of the primary molars and canine for the buccal segment in question to get the leeway space for that area.

Question 13

If there is lower anterior crowding, what are the options for management in the mixed dentition?

Answer 13

1. Space redundancy - Wait until the permanent dentition has erupted to close the space, do bonding, or consider tooth replacement.
2. No crowding - Even with no crowding, long-term alignment cannot be guaranteed in some patients. Development of alignment problems later on in life may benefit from retention.
3. Mild crowding (1 to 4 mm) - Use of a lower lingual arch to hold the leeway space (lingual arches typically hold only 3 to 5mm of space), disking of select primary teeth.
4. Moderate crowding (5 to 9mm) - Flaring of anterior teeth, distalization of permanent first molars, or arch expansion with appliances such as a lip bumper or limited orthodontic with bands on the molars, brackets on the incisors (“2x4”) and open coil springs.
5. Severe crowding (10mm or more): Serial extraction, or wait until the permanent dentition and consider extraction, followed by full orthodontics.

Question 14

Why should lower lingual arches not be placed prior to eruption of the permanent lower incisors?

Answer 14

The anterior portion of the lingual wire can interfere with normal eruption of the incisors.

Question 15

What can oral habits cause?

Answer 15

1. Decreased arch width
2. Crossbite
3. Increased overjet
4. Decreased overbite or open bite

Question 16

What two important concepts are necessary to correct an oral habit?

Answer 16

1. Often, parental anxiety and scolding about the habit increases its intensity, instead of ameliorating it.
2. The child must be old enough to understand the need to stop the habit and must want to stop the habit for interventions to be helpful.

Question 17

What do you do if a patient is determined to continue an oral habit despite an intra-oral appliance?

Answer 17

In these cases, the patient may not truly want to stop the habit and a child therapist should be consulted to determine if there are other psycho-social issues involved.

Question 18

What are the three main areas of treatment for a patient with an oral habit?

Answer 18

1. Behavior modification: This technique uses positive reinforcement to encourage the child’s compliance. E.g., a rewards calender (a star is placed for each successful day of no oral habit and at the end of each week a small reward is given, usually works within a month’s time)
2. Extra-oral means: Various options are available including wrapping an Ace bandage around the elbow at night to keep the child from bending her arm to place their digit in her mouth (must be careful not to cut off blood circulation), placement of bitter-tasting liquids on the digit, and use of a glove-like appliance that covers the thumb and straps around the wrist.
3. Intra-oral appliances: Palatal appliances with cribs, loops, irritating spurs, or beads can all be helpful.

Question 19

What is the main difference between non-nutritive sucking habits that are benign and those that have deleterious oral effects?

Answer 19

Patients with habits of minimal frequency, duration or intensity have no or milder deleterious effects.

Question 20

What two important concepts are necessary to correct an oral habit?

Answer 20

1. Often, parental anxiety and scolding about the habit increases its intensity, instead of ameliorating it.
2. The child must be old enough to understand the need to stop the habit and must want to stop the habit for interventions to be helpful.

Question 21

What are the three main areas of treatment for a patient with an oral habit?

Answer 21

1. Behavior modification: This technique uses positive reinforcement to encourage the child’s compliance. E.g., a rewards calender (a star is placed for each successful day of no oral habit and at the end of each week a small reward is given, usually works within a month’s time)
2. Extra-oral means: Various options are available including wrapping an Ace bandage around the elbow at night to keep the child from bending her arm to place their digit in her mouth (must be careful not to cut off blood circulation), placement of bitter-tasting liquids on the digit, and use of a glove-like appliance (or sock) that covers the thumb and straps around the wrist.
3. Intra-oral appliances: Palatal appliances with cribs, loops, irritating spurs, or beads can all be helpful.

Question 22

What is the main difference between non-nutritive sucking habits that are benign and those that have deleterious oral effects?

Answer 22

Patients with habits of minimal frequency, duration or intensity have no or milder deleterious effects.

Question 23

In managing a patient’s sucking habit, what is the most critical component to consider for success?

Answer 23

The child must be old enough to understand the need to stop the habit and must want to stop the habit for interventions to be helpful.

Question 24

Deleterious effects on the teeth and supporting structures are minimized if children will stop their digit sucking habits by approximately what age?

Answer 24

Before age 6; that is, before eruption of the permanent teeth.

Question 25

In a crossbite, what is the importance of a functional shift of the mandible?

Answer 25

The longer a patient with a shift retains that shift, the more long-term skeletal asymmetries will develop. Having these crossbites with shifts are like wearing a full-time functional appliance; however, unlike the appliances, the effect is not beneficial.

Question 26

What kind of shifting is normally seen in an anterior crossbite?

Answer 26

The mandible will tend to shift in a protrusive direction.

Question 27

What is the difference in the teeth between an anterior crossbite with significant protrusive shift vs one with little to no protrusive shift?

Answer 27

1. If there is significant protrusive shift: the maxillary incisors will be very upright and the crossbite is more dental in nature and may be managed by flaring the maxillary incisors labially.
2. If there is little to no protrusive shift: the maxillary incisors will not necessarily upright, the patient should be evaluated cephalometrically for a class III skeletal problem.

Question 28

What kind of occlusion will be seen with a bilateral posterior crossbite?

Answer 28

A mandibular shift from initial contact into maximum intercuspation, a midline shift during closure, and a crossbite.

Question 29

What can cause a bilateral posterior crossbite?

Answer 29

Maxillary skeletal constriction or dental buccal segment tipping.

Question 30

What is seen in a bilateral posterior crossbite and not a unilateral posterior crossbite?

Answer 30

Bilateral crossbite patients will exhibit a shift of the dental midlines during closure, whereas, those with unilateral crossbites will not.

Question 31

What is the difference in appliances for bilateral vs unilateral posterior crossbites?

Answer 31

Many appliances (W-arch, Hyrax, Quad helix, Expansion Plate, etc.) to varying extents, will effectively correct bilateral crossbites, both dental and skeletal. However, true unilateral crossbites benefit from an appliance design that only addresses the maxillary arch side that is causing the crossbite.

Question 32

What are some basic pros and cons of early orthodontic treatment?

Answer 32

Pros:

1. Correction is done sooner, so patient enjoys outcome sooner.
2. Younger children tend to be more compliant.
3. Often parents want treatment sooner.
4. Less skeletal asymmetry the sooner correction is done.
5. Can alleviate traumatic occlusions.

Cons:

1. Less efficient; therefore, more appointments spread out over longer treatment time with increased costs.
2. No improved results for earlier treatment in most cases.
3. Need for between phase retention until permanent dentition treatment commences.

Question 33

When correcting anterior and posterior crossbites, is it important to disclude or “open the bite” so that the treatment mechanics can move the affected teeth past the point of the crossbite?

Answer 33

No. An often misunderstood concept is that occlusal acrylic pads or other bite opening technique is needed to correct crossbites. In fact, this is generally not necessary. The main reasons for doing so would be if the crossbite itself interferes with the appliance to be used or if there is pathology associated with the affected teeth.

Question 34

An obtuse interincisal angle, “upright incisors,” is a sign of which type of problem associated with an anterior crossbite, dental or skeletal?

Answer 34

Upright incisors are an indication of a dental etiology.

Question 35

Is it true that a distinct advantage of early orthodontic treatment is that mandibular skeletal length can have clinically significant increases with early functional type appliances?

Answer 35

No, research has shown that typical initial significant improvements in mandibular length do not maintain themselves when patients are re-examined at the end of normal growth.

In other words, treatment of malocclusions early does not result in an otherwise unobtainable mandibular skeletal lengthening.

Question 36

What are the names of three common orthognathic surgical procedures and give an overview of each?

Answer 36

1. Maxilla-Le Fort I osteotomy: Involves a transverse sectioning of the maxilla to accomplish various repositionings of the bone for proper three-dimensional alignment with the base of the skull and mandible.
2. Mandible-bilateral split sagittal osteotomy: Involves a vertical sectioning of the mandible in the mandibular ramus, distal to the dentition for the most part to allow either forward or backward repositioning of the anterior segment of the mandible.
3. Chin button-genioplasty: This procedure involving the bony portion of the chin allows realignment or recontouring of the chin to enhance its position relative to the face.

Question 37

Hemifacial microsomia includes what constellation of problems?

Answer 37

Underdevelopment of one side of the mandible, which involves problems with the ear and hearing.

Question 38

What are the timing considerations when considering extraction of badly carious first permanent molar to be substituted by the second permanent molar?

Answer 38

If possible, it is advantageous to extract the first permanent molar months prior to eruption of the second permanent molar (by age 10) to facilitate mesial drift, molar substitution and uprighting.

Question 39

List some advantages of team management of craniofacial patients?

Answer 39

Increased coordination and communication between specialty providers, development of management protocols for efficiency and effectiveness, team cooperation and consultation for increased quality of care, and reduced patient/parent absence from school/work bc appointments are simultaneous and coordinated.

Question 40

What are some common procedures to manage high-caries risk patients during orthodontic treatment?

Answer 40

Do not start treatment until caries risk is considered to be low. Increase oral hygiene (brushing, flossing, high frequency toothbrushes, parental involvement in hands-on oral hygiene procedures), at-home fluoride mouth rinses, in-office fluoride varnish administration, fluoride-releasing orthodontic elastic ties, use of remineralizing products containing amorphous calcium phosphate (ACP).