Lecture 14 Flashcards
1
Q
what are 6 things we can control in orthodontics?
A
- diagnosis -treatment plan
- selection of orthodontic appliances
- brackets, wires, bands
- placement of orthodontic appliances
- forces on teeth
2
Q
what are a bunch of things we cannot control, or have limited control over, in orthodontics?
A
patient compliance, growth, tooth size and form, root resorption, ankylosis, impacted teeth, abnormal tooth eruption, bone loss, gingival recession, periodontal disease, temporomandibular joint disorders, muscle/oral habits (tongue, thumb), post treatment tooth movement
3
Q
what is involved in the questionnaire/consultation appointment?
A
- chief concern
- medical history
- dental history
- habits
4
Q
what is involved in the clinical evaluation appointment?
A
oral health (dental, periodontal, caries, recession, bone loss), TMJ evaluation (max opening, lateral range, CR/CO), facial and dental appearance, pathology, radiographic examination (pano - missing, supernumerary, impacted), molar and canine relationship, transverse and anterior posterior relationships, dentally and skeletally, crowding, spacing, overjet, overbite, curve of spee and wilson, midlines, profile, chin deviation, developmental age compared to dental age, growth disharmony, lip position, primary teeth eruption, tooth size/shape
5
Q
when evaluating medical history, along with regular dental health evaluations, there are also drugs that can interfere with orthodontic treatment. describe this.
A
some drugs can stimulate tooth movement (these are unlikely to be encountered, although efforts to produce them continue), direct injection of prostaglandin into the PDL has been shown to increase the rate of tooth movement, but this is quite painful (similar to a bee sting)
6
Q
which two types of drugs are known to depress the patient’s orthodontic response and may influence treatment?
A
- prostaglandin inhibitors - pain control
- bisphosphonates - used in the treatment of osteoporosis
7
Q
osteoporosis is commonly seen in postmenopausal women but can be associated with either males or females. bisphosphonates bind to ___ in bone and act as specific inhibitors of ___.
A
- hydroxyapatite
- osteoclast-mediated bone resorption
8
Q
T or F: bisphosphonates are incorporated into the structure of the bone and are quickly eliminated
A
- false
- while it is true that bisphosphonates are incorporated into the structure of bone, they are actually slowly eliminated over a period of years, so merely stopping the drug does not eliminate all of its effects
9
Q
most of the bisphosphonate drug is absorbed on the surface of the bone, which makes orthodontic treatment possible after ___ months if bisphosphonate therapy is discontinued
A
3 months
10
Q
___ are very important in the inflammatory response, and are formed from arachidonic acid, which in turn is derived from ___
A
- prostaglandins
- phospholipids
11
Q
___ reduce prostaglandin synthesis by inhibiting the formation of arachidonic acid
A
corticosteroids
12
Q
what are 2 examples of corticosteroids?
A
- prednisone
- dexamethasone
13
Q
NSAIDs are prostaglandin inhibitors that work on a chemical level by blocking ___ and ___ enzymes, which play an important role in making prostaglandins
A
COX-1 and COX-2
14
Q
___ is a potent NSAID that is used in the treatment of arthritis and can decrease orthodontic tooth movement
A
indomethacin
15
Q
what type of NSAIDs typically don’t effect orthodontic treatment?
A
- over the counter NSAIDs like aspirin, ibuprofen, and aleve, which are short acting
- these are not a problem if they are being use to control acute pain
- however, if an adult or child is being treated for arthritis and is chronically taking over the counter NSAIDs, then this medication could become a problem
16
Q
what other drugs can affect prostaglandin levels and effect the response to orthodontic force?
A
- tri-cyclic antidepressants (doxepin, imipramine)
- antiarrhythic agents (procaine)
- antimalarial drugs (quinine)
- anticonvulsant (phenytoin/dilantin)
17
Q
what should the consultation outcome include?
A
- informed consent to possible treatment plan options
- the doctor’s role at that point is to determine the treatment plan details, considering effectiveness and efficiency of the various methods to achieve the desired outcome
18
Q
during orthodontic treatment planning, what should the cast analysis include?
A
symmetry, spacing, crowding, tooth size, and occlusal relationships
19
Q
orthodontic casts have traditionally been trimmed with symmetric bases, where the backs are trimmed perpendicular to the midsagittal line. what does this allow?
A
it allows the models, so that when they are placed on their backs, the models can be picked up in maximum intercuspation
20
Q
T or F: when trimming orthodontic casts, precise angulation is more important than symmetry
A
- false
- symmetry is more important than precise angulation
21
Q
what are virtual dental casts?
A
- they are produced from laser scans of impressions
- accurate measurements can be done on a virtual dental cast
22
Q
when examining orthodontic models, what measurements are evaluated?
A
- occlusal relationship (class I, II, III molar and canine relationships)
- tooth size, shape, and morphology
- overjet, overbite, and open bite (mm measurements describing the severity of each individual problem)
23
Q
if the incisors flare forward, they occupy an arc of a larger circle, which provides more space to accommodate the teeth and alleviate ___. conversely, if the incisors move lingually, there is less space and ___ becomes worse
A
- crowding
- crowding
24
Q
crowding and protrusion of incisors must be considered two aspects of the same thing: how crowded and irregular the incisors are reflects both ___ and ___
A
how much room is available and where the incisors are positioned relative to supporting bone
25
space analysis requires a comparison between ___ and \_\_\_
the amount of space available for the alignment of the teeth, and the amount of space required to align them properly in the dental arches
26
what are three ways space analysis can be done?
* directly on the dental casts
* by a computer algorithm after appropriate digitization of the arch and tooth dimensions by scanning the casts
* or intraorally
27
when doing a space analysis, what is the first step?
* calculation of the space available
* this is accomplished by measuring arch perimeter from the mesial of one first molar to the mesial of the other over the buccal cusps and incisal edges
* this can be done by dividing the dental arch into segments that can be measured as straight line approximations of each arch
* another method can be used by contouring a piece of wire or curved line on a computer image to the arch, then measuring the length of the wire or have the computer compute the length of the line
28
what is the second step of the space analysis?
* calculate the amount of space required
* measure the MD width of each erupted tooth from contact point to contact point and estimate the widths of the size of the unerupted teeth
* available space minus space required is used to determine the amount of crowding or spacing
29
in order for space analysis to be correct, what are 3 assumptions?
* the AP position of the incisors in correct
* the space available will not change because of growth and dental compensatory tipping
* all the teeth are present and are reasonably normal in size
* \*none of these assumptions can be taken for granted, and all of them must be kept in mind when space analysis is performed
30
\_\_\_ is critical to space analysis and information about incisor position must be available from the clinical exam or cephalometric analysis prior to performing space analysis
dental incisor position
31
the assumption that space is available will not change during growth is valid for most, but not all, children. describe this.
* in a child with a well-proportioned face, there is little or not tendency for the dentition to be displaced relative to the jaw during growth
* teeth often shift anteriorly or posteriorly in a child with a jaw discrepancy, for this reason space analysis is less accurate and less useful for children with skeletal problems
32
how can unerupted teeth be predicted during a mixed dentition analysis?
* moyers analysis: measure mandibular incisors and then refer to a chart for prediction values
* tanaka and johnston prediction values
33
the bolton analysis is a cast analysis that was designed following observation that ___ was important to ideal occlusion
tooth size
34
in the bolton analysis, in order to obtain the proper interdigitation and arch coordination when the molars are in a class I relationship, the ___ has to be proportional to the \_\_\_
dimension of the lower teeth has to be proportional to the dimension of the upper teeth (for a patient to have a normal overbite and overjet, the lower teeth must occupy a dental arch that is smaller than the upper arch)
35
bolton calculated that a ___ between the upper and lower dentition was present when the occlusion was perfect
constant proportion
36
bolton determined that the sum of the MD dimension of the lower teeth must be equal to \_\_\_% the sum of the MD dimension of the upper teeth
91%
37
bolton also discovered that a satisfactory class I canine occlusion was only possible if a ___ was present between the upper and lower anterior teeth
specific proportion
38
the sum of the size of the MD dimension of the lower anteriors must be \_\_\_% of the sum of the size of the MD dimension of the upper anterior teeth
77%
39
the bolton analysis is now mainly used for \_\_\_
anterior region
40
what 3 things does photographic analysis examine?
* profile type (concave, convex, orthognathic)
* facial symmetry (chin, eyes, nose, cheeks)
* lip position (protrusion, retrusion)
41
vertical facial proportions in the frontal and lateral views are best evaluated in the context of \_\_\_, which are typically equal in height in well-proportioned faces
facial thirds
42
in modern caucasians, the ___ facial third is often slightly longer than the ___ third
* lower
* central
43
which facial third is further divided into its own thirds, and what are they?
* lower third
* the corners of the mouth should be 1/3 the way between the base of the nose and chin
* the chin and lower lip should occupy 2/3 of the lower third
44
in the frontal plane, an ideally proportioned face can be divided into \_\_\_, \_\_\_, and ___ equal fifths
central, medial, and lateral
45
describe how the frontal plane is divided into fifths
* the separation of the eyes and the width of the eyes, which should be equal, determine the central and medial fifths
* the lateral fifths are from the outside corner of the eye to the edge of the face
* the nose and chin should be centered within the central fifth, with the width of the nose the same as, or slightly wider than, the central fifth
* the interpupillary distance should equal the width of the mouth
46
everyone typically has some ___ in their facial appearance
asymmetry
47
the degree of asymmetry determines if the asymmetry is within normal ranges. typically, the asymmetry is considered abnormal if it is \_\_\_
noticeable to the general public or patient
48
\_\_\_ are the best way to illustrate normal facial asymmetry
* composite photographs
* this technique dramatically illustrates the difference in the two sides of a normal face
49
usually, the ___ side of the face is a littler larger than the ___ side
right side is a little larger than the left side
50
profile convexity or concavity results from a \_\_\_, but does not by itself indicate which jaw is at fault
disproportion in the size of the jaws
51
a ___ facial profile indicates a class II jaw relationship, which can result from either a maxilla that projects too far forward or a mandible too far back
convex
52
a ___ facial profile indicates a class III relationship, which can result from either a maxilla that is too far back or a mandible that protrudes forward
concave
53
ENT doctors referral and allergists are often needed for what patients?
dolicocephalic, adnoid facies, long face syndrome
54
what is the clinical presentation of brachiocephalic patients?
* low mandibular plane angle
* short anterior face height
* deep bite
* patients typically follow a class III growth pattern with low horizontal mandibular growth
55
bimaxillary dentoalveolar protrusion is seen in the facial appearance in what 3 ways?
* excessive separation of the lips at rest (lip incompetence)
* excessive effort to bring the lips into closure (lip strain and mentalis activity)
* prominence of lips in the profile view
* \*remember that all 3 soft tissue characteristics must be present to make the diagnosis bimaxillary dentoalveolar dental protrusion
56
the general guideline for lip separation at rest should be no more than \_\_\_mm, which holds for all racial groups
4mm
57
the guideline for lip separation at rest holds for all racial groups because different racial groups and individuals within those groups generally have the same degrees of lip prominence that are independent of tooth position
* false
* different racial groups and individuals within those groups have the different degrees of lip prominence that are independent of tooth position
58
because different racial groups and individuals within those groups have different degrees of lip prominence, excessive dental protrusion must be a ___ diagnosis
* clinical diagnosis
* it cannot be made accurately from cephalometric radiographs
59
the usual cause of excessive display of maxillary gingiva is a long face due to \_\_\_
excessive downward growth of the maxilla, which moves the maxilla down below the upper lip and results in a disproportionately long lower 3rd of the face
60
is gingival display in adulthood viewed the same as gingival display in childhood?
* no, because the gingival recession that accompanies eruption is incomplete
* this should also not be confused with gingival display due to a combination of incomplete eruption and/or a short upper lip (botox injections, surgery, etc.)
61
growth of the ___ as a patient ages typically reduces some excessive gingival display
upper lip
62
display of all the ___ and some ___ on smiling is a youthful and appealing characteristic
maxillary incisors and some gingiva
63
T or F: less display of maxillary incisors and some gingiva is less attractive, although it is not considered objectionable by lay observers
* true
* there is a considerable range of maxillary incisor display that observers consider acceptable
64
as a person ages, less ___ and ___ show is normal
* incisor and gingiva
* this happens as the upper lip lengthens with age and the teeth wear down from use
* having less maxillary incisal show gives the face an older appearance
65
with respect to facial analysis and incisor display, the anterior occlusal plane should be parallel to the \_\_\_
interpupillary line
66
throat form is evaluated in terms of the contour of the \_\_\_
* submental tissues
* straight is better; longer throat length is better, up to a point
67
both ___ and ___ contribute to a stepped throat contour, which becomes a "double chin" when extreme
submental fat deposition and a low tongue posture
68
chin-throat angles closer to ___ degrees are better
90
69
the naso-labial angle is the angle formed between the ___ and the \_\_\_; ideally, this angle should be ___ or \_\_\_
* base of the nose and the upper lip
* perpendicular or slightly obtuse
70
the naso-labial angle can be influenced by the position of the \_\_\_
maxillary incisors
71
extraction of premolars can cause the naso-labial angle to ___ as the maxillary incisors are retracted. what patient can this be beneficial for?
* open up
* this can be beneficial to a patient that has an acute naso-labial angle with lip incompetency
72
\_\_\_ can also be incorporated with orthodontic treatment to improve the naso-labial angle
rinoplasty
73
the mandibular plane angle can be visualized clinically by placing a mirror handle or other instrument along the \_\_\_
border of the mandible
74
a flat mandibular plane angle correlates with what 4 things?
* short anterior facial height
* braciocephalic
* class III skeletal relationship
* anterior deep bite
75
a high mandibular plane angle correlates with what 4 things?
* long anterior facial height
* dolicocephalic
* class II skeletal relationship
* anterior open bite
76
the width of the maxillary dental arch, as seen on smile, should be proportional to the \_\_\_
* width of the midface
* a broad smile is appropriate for a face with relatively large width across the zygomatic arches
* a narrower smile is preferred when the face width is narrow across the zygomatic arches
77
the ___ is the relationship of the curvature of the lower lip to the curvature of the maxillary incisors
* smile arc
* the appearance of the smile is best when these two curvatures match
* a flat or reverse smile arc is less attractive in both males and females
78
in ideal tooth width proportions, it can be seen that the width of the lateral incisors is \_\_\_% of the width of the central incisor; the apparent width of the canine is \_\_\_% of the width of the lateral incisor; the apparent width of the first premolar is \_\_\_% of the width of the canine
62% for all
79
in ideal tooth width proportions, the width of the tooth should be about \_\_\_% of its height
80% (or, the length should be 20% longer than the width)
80
for ideal appearance, the contour of the gingiva over the maxillary central incisors is a \_\_\_, with the zenith (height of contour) located \_\_\_
* horizontal half-ellipse (flattened horizontally)
* distal to the midline of the tooth
81
in contrast to the central, the maxillary lateral incisor has a gingival contour of a \_\_\_, with the zenith located at the \_\_\_
* half-circle
* midline of the tooth
82
the gingival contour of the canine is a \_\_\_, with the zenith located \_\_\_
* vertical half-ellipse (higher contour than a half circle)
* just distal to the midline
83
the gingival height should be the same for the central incisors and canines, with the lateral incisors being \_\_\_mm below a line connecting the canine gingival height and central gingival height
0.5-1mm
84
the contact points of the maxillary teeth move progressively ___ from the central incisors to the premolars, so that there is a progressively ___ incisal embrasure
* gingivally
* larger
* the embrasure angle gets progressively larger going from the central incisors posteriorly
85
what is a "connector", with respect to contact points?
* the area that looks to be in contact in an unmagnified frontal view
* the connector decreases in size from the centrals posteriorly
* connectors that are toot short often are part of the problem when black triangles appear between teeth, which can be caused by poor tooth shape or a defect in the gingival tissues
86
what are the two primary diagnostic xrays used in orthodontics?
cephalogram and panoramic xray
87
the cephalometric radiograph is taken with the patient in a ___ head position
* neutral
* neutral head position is having the patient stand in a relaxed natural position when the xray is taken staring at the horizon
* NHP is preferred in modern cephalometrics to anatomic head positioning
88
the cephalogram is used to diagnose ___ and ___ classifications by using angular and linear measurements to compare these measurements to standard normal values
skeletal and dental classifications
89
the panoramic xray is used to evaluate what 7 things?
missing teeth, extra or abnormal teeth, abnormal eruption patterns, evaluate the TMJ, bone level, root structure (length/resorption), and pathology
90
T or F: hand wrist radiographs can be used to determine the chronology of skeletal development
* true
* by looking at the ossification and development of the carpal bones of the wrist and the metacarpals and of hands and phalanges of the fingers
* these xrays can be compared to age standards in a reference atlast
91
in hand wrist radiographs, the ___ or ___ are considered landmarks to obtain an estimate of the timing of the adolescent growth spurt
ulnar sesamoid or hamate bones (calcification of the hook)
92
growth in ___ of the jaws is generally completed before the adolescent growth spurt begins; growth in ___ of the jaws continues throughout the growth spurt.
* width
* length
93
the state of physical maturity or skeletal developement correlates well with the \_\_\_, which is used to predict how much jaw growth can be expected
jaw growth
94
T or F: after sexual maturity, much more growth is expected, and therefore growth modification is attempted
* false
* much less growth is expected, and therefore growth modification is not attempted
95
in cephalometrics, the ___ structure is broken down into skeletal and dental components, which are then compared to normal values
craniofacial
96
what are all of the independent functional units of the craniofacial structure that can be displaced relative to each other?
* cranium and cranial base
* skeletal maxilla and nasomaxillary complex
* skeletal mandible
* maxillary teeth and alveolar process
* mandibular teeth and alveolar process
97
the major goal of cephalometric analysis is to establish \_\_\_
* the relationship of the independent functional units in both the anterior-posterior and vertical planes of space
* the objective is to visualize the contribution of skeletal and dental relationships to the malocclusion
98
cephalometric analysis can distinguish and clarify the differing dental and skeletal contributions to ___ that can be presented by identical dental relationships
malocclusion
99
cephalometric measurements and other analytic procedures are a means of understanding the ___ and ___ for an individual patient
dental and skeletal relationships
100
cephalometrics can be used to identify and measure ___ and ___ by comparison of different cephalograms over a period of time
* growth and tooth movement
* this is done by superimposing the different cephalograms onto one another
101
what are 3 major superimpositions used in orthodontics?
* superimposition on the anterior cranial base along the SN line
* superimposition on the maxilla, specifically on the contour of the palate behind the incisors and along the palatal plane (shows changes of the maxillary teeth relative to the maxilla)
* superimposition on the mandible, specifically on the inner surface of the mandibular symphysis and the outline of the mandibular canal and unerupted 3rd molar crypts (shows changes in the mandibular ramus and condylar process, and changes in the position of the mandibular teeth relative to the mandible)
102
once you have finished your consultation, clinical exam, and analysis of diagnostic records, you then formulate a database of values for each patient; you then determine which values in the database are \_\_\_
the most severe, then list the patients problems in a prioritized problem list
103
the first step in treatment planning is to consider the management of the \_\_\_
pathologic problems (these must be under control before orthodontic treatment begins)
104
orthodontic treatment in the presence of ___ can accentuate the pathology
active disease
105
your prioritized problem list should evaluate the patient using the values in their database in all 3 \_\_\_
planes of space
106
the patient should be evaluated for abnormalities in what 4 areas?
skeletal, dental, soft tissue elements, all 3 planes of space
107
once you have identified your problem list, you can then make a ___ for the patient, and formulate a ___ which addresses all the problems in your problem list
* diagnosis
* treatment plan
* it is also important to have alternative treatment plans and present them to the patient, and make sure they understand the compromises and benefits with each treatment option
108
the development of the treatment plan should include what 4 things?
* timing of the treatment
* complexity of the treatment that would be required, and the duration of treatment
* the predictability of success with a given treatment approach including alternative treatment plans
* the patient's and parent's goals and desires are addressed
109
a ___ is used when taking a cephalometric xray so the soft tissue can be visualized
soft tissue shield
110
\_\_\_ describe anatomic points that are used in measuring a cephalogram for analysis
* anatomic landmarks
* when these measurements are compared to "normal", they aid in diagnosis and in deciding what treatment can be done to correct the problems
111
certain structures fall in the midsaggital plane, and are therefore identified as a \_\_\_
* single point
* many other structures occur on both sides of the face
112
how are bilateral structures measured in cephalometrics?
* the bilateral structures result in 2 points that are not coincident due to enlargement by the xray beam
* these points are then bisected, taking an average of the 2 points to provide a single, measurable point
113
what are the basic steps to trace a lateral cephalogram?
1. trace the cranial base
2. trace key ridge, orbits, and PTM (pterygomaxillary fossa)
3. trace the palate, maxillary incisors, and molars
4. trace the mandible and external auditory meatus
5. trace the soft tissue profile
114
the tear-drop shape of the PTM tracing points to the ___ of the maxillary bone
posterior nasal spine
115
the anterior aspect of the maxilla can be difficult to identify especially with poor positioning of the \_\_\_
soft tissue shield
116
after the ceph tracing is completed, ___ are added
ceph landmarks
117
what is considered the most stable point in a growing skull from a cephalometric standpoint?
the sella
118
where is the sella located?
center of the pituitary fossa of the sphenoid bone (S)
119
where is the nasion located?
intersection of the internasal suture with the nasofrontal suture in the midsagittal plane (N)
120
where is the orbitale located?
lowest point of the floor of the orbit, the most inferior point of the external border of the orbital cavity (bisected) (Or)
121
where is the porion located?
the point on the upper most portio of the external auditory meatus (bisected) (Po)
122
where is the anterior nasal spine located?
most anterior bony point on the maxilla at the base of the nose (ANS)
123
where is the posterior nasal spine located?
posterior limit of the bony palate (PNS)
124
what is the A point?
deepest point of the curve of the maxilla, between anterior nasal spine and the dental alveolus. usually located just opposite the root tip of the central incisor
125
what is the B point?
most posterior point in the concavity along the anterior border of the symphysis, usually opposite the root tip of the mandibular incisor
126
what does the B point represent?
the anterior limit of the mandibular base
127
where is the pogonion located?
the most anterior point on the anteior curvature of the mandibular symphysis (Pog)
128
where is the gnathion located?
the most outward and everted point on the profile curvature of the symphysis of the mandible, located midway between pogonion and menton (Gn)
129
where is the menton located?
the most inferior point on the mandibular symphysis (Me)
130
where is the gonion located?
the point at the middle of the curvature at the angle of the mandible (Go)
131
what does the gonion represent?
the junction of the ramus and the body of the mandible at its posterior inferior aspect (bisected)
132
what is the SN?
plane formed by connecting the sella (S point) to the nasion (N point)
133
what is the frankfort horizontal?
formed by connecting the porion and orbitale (FH)
134
what is the palatal plane?
formed by a line connecting the anterior nasal spine to the posterior nasal spine (PP)
135
what is the occlusal plane?
formed by a line connecting the distal cusp of the mandibular first molar and the incisal edge of the mandibular incisors (OP)
136
what is the mandibular plane?
the plane formed by connecting the menton to the gonion (MP)
137
what is the y-axis?
the line connecting the sella to the gnathion (S-Gn)
138
which cephalometric plane is used as an indicator for vertical facial growth tendency?
y-axis
139
an SNA angle greater than 82 degrees signifies \_\_\_
maxillary prognathism
140
an SNA angle less than 82 degrees signifies \_\_\_
maxillary retrognathism
141
an SNB angle greater than 80 degrees signifies \_\_\_
mandibular prognathism
142
an SNB angle less than 80 degrees signifies \_\_\_
mandibular retrognathism
143
the ANB angle is normally ___ degrees
2
144
a class I skeletal profile has an ANB angle of \_\_\_
2 degrees +/- 2 degrees
145
a class II skeletal profile has an ANB angle of \_\_\_
\>4 degrees
146
a class III skeletal profile has an ANB angle of \_\_\_
\<0 degrees
