Orthodontic Records And Case Evaluation Flashcards
What are some of the most important drugs to note upon taking medical history?
Drugs that may trigger hyperplastic gingival response, such as phenytoin, calcium channel blockers, and immunosuppressive, as well as medications that may inhibit orthodontic tooth movement such as bisphosphonates or prostaglandin inhibitors
Which allergies are most noteworthy when taking medical history?
Allergies, especially to nickel or latex
In addition to obtaining the CC and medical history, what are some other points of information that are important when interviewing the patient?
Any facial or dental trauma, extractions, habits, and oral hygiene regimen
Possible familial patterns of malocclusion
Voice change in boys and menarche in girls can be used to assess the stage of pt’s development
What are some additional aspects that should be covered in the clinical examination in an adult (as opposed to an adolescent)?
Periapical and bitewing radiographs
Probing depths and document a periodontal screening index (PSI) to document the status of the periodontium prior to any orthodontic treatment
What are the five main areas of interest to the orthodontist in clinical examination (in regards to jaw and occlusal function)?
Mastication Speech Breathing mode Orofacial dysfunctions TMJ function
How is the TMJ function examined?
Initially questioned about existing TMJ problems
Manipulation
Auscultation
Palpation
Evaluation of the pts range of motion
Ideally, mandibular movements should have a normal range of ___mm maximal opening, and ___mm lateral excursions.
50mm
10mm
Functional shifts between MI and CR outside the normal range of __mm need to be recorded. Why?
1.5mm
They have been correlated with increased TMDs
TMD is subdivided into ___ and ___
True pathologies of the TMJ
Myofascial pain dysfunction (MPD) (which affects masticatory and cervical muscles.
A history of prolonged sucking habits, poor educational advancement, sleepwalking in younger children, and enuresis in older children may be related to __
Emotional problems
What are the 5 ages that need to be considered in orthodontic care?
Chronological Skeletal Dental Mental Emotional
If a treatment plan demands a skeletal dentofacial orthopedic modification, when should the patient be treated?
As close as possible to the peak velocity of growth
Thus, the use of headgear and/or functional appliances appears more effective if applied at or slightly after the onset of the pubertal growth spurt in the late mixed dentition.
What are the different classifications of a malposed tooth?
Inclinated (centrically or eccentrically)
Totally displaced
Rotated
Transposed
What is mesioversion?
A malposed tooth displaced toward the facial midline
What is distoversion?
Malposed tooth is located further away from the midline
What is labioversion?
If an incisor or canine is misplaced outside the arch form toward the lip
What is buccoversion?
If a posterior tooth is dislocated toward the cheek
What is linguoversion?
If a tooth is inclined toward the tongue
What is infraversion
When a tooth is not erupted to the occlusal plane
What is supraeruption?
An overerupted tooth
What is torsiversion?
A tooth rotated on its own axis
What is transposition or transversion?
Denotes a positional interchange of two adjacent teeth
Where is transposition most commonly found?
Most commonly found in the maxilla
Incidence is 1 in 300
What is the apical base arch?
The area of alveolar bone on the level of the root apices of the teeth
What is the basal arch?
Formed by the maxillary and mandibular corpus. Its dimensions are stable and unaffected by tooth loss or alveolar resorption
How is the dental arch perimeter measured?
Through the contact points of the teeth and ideally should be congruent to the sizes of the alveolar and basal arches
Which arch is considered to be teh “diagnostic arch”. Why?
Mandibular arch
Because of the cortical bone on the facial and lingual surfaces.
In contrast to the intermolar width, which significantly increases in the maxillary arch between 3 and 13 years of age, the mandibular intercanine distance increases during the transition of primary to permanent dentition and then decreases slightly until adulthood
What are the most common arch forms, in order from most common to least common?
Ovoid
Tapered
Squared
Define arch length discrepancy. How is it determined?
The difference between the available arch length and the required arch length
It is determined by measuring the mesiodistal tooth widths of the permanent teeth from mesial of permanent first molars
What is the Bolton analysis?
Offers a method to determine the ratio of the mesiodistal widths of the maxillary versus the mandibular teeth to determine tooth size discrepancy and its interarch effects.
True or false… tooth size discrepancies in the anterior region can be corrected with treatment changes in the posterior teeth.
False… tooth size discrepancies in the anterior region can only be corrected with compensations in the anterior region. Thus, the Bolton analysis consists of an anterior ratio analysis, designed to identify incompatibilities in anterior teeth, or a whole dentition ratio, which, when compared to the anterior ratio, determines the discrepancies of the posterior teeth.
How is the Bolton analysis conducted? (Anterior ratio)
The anterior ratio is calculated by dividing the sum of the mesiodistal widths of the mandibular six anterior teeth by the sum of the mesiodistal widths of the maxillary anterior teeth and then multiplying by 100.
What is the mean anterior ratio (Bolton analysis)?
What is the mean overall ratio?
- 2
91. 3
How is the Bolton overal ratio conducted?
Calculated according to the same principle as the anterior ratio but is calculated by dividing the sum of the mesiodistal widths of the mandibular right first molar tooth to the left first molar tooth by the sum of the MD widths of the sum of the maxillary first molar widths.
What do Bolton ratio standardization tables help determine?
Studying the Bolton ratios using standardized tables for comparison of the anterior and overall ratio relationship helps to estimate the overbite and overjet relationship that likely will be obtained through orthodontic treatment as well as to identify occlusal discrepancies produced by interarch tooth size incompatibilities.
___% of the US population presents with a normal occlusion
30%
About ___% of the US population presents with a class 1 malocclusion
50%
The prevalence of class 2 malocclusion is __-__%
15-20%
What is the prevalence of class 3 malocclusion?
Less than 1%
Define laterognathy
If the center of the mandible is not aligned with the facial midline in rest position, a true asymmetry is present and is termed laterognathy
Define laterocclusion
If a midline shift of the mandible is discernible only in occlusion within a symmetric skeleton, a functional shift is most likely the cause of this phenomenon, and is called laterocclusion
What happens if a patients posterior crossbite with functional shift is not treated early with maxillary expansion and equilibration?
Facial asymmetry becomes permanent
What are some things that may contribute to dental arch asymmetry?
Ankylosis of primary molars with resultant tipping of the adjacent teeth
Ectopic erutpion of maxillary permanent first molars that leads to premature loss of primary second molar and subsequent loss of arch length
Congenitally missing or supernumerary teeth
Space loss cause by interproximal caries or loss of teeth
Are digital models as reliable for diagnosis as stone models?
Yes, with an accuracy of +/- 0.01mm
What is a prognostic/diagnostic setup?
When is it useful?
Process that involves cutting teeth off a working cast and resetting them into a more desirable position to visualize space concerns and ascertain amount and direction of tooth movement before treatment is initiated.
It may be especially helpful in interdisciplinary cases using implants, unusual extraction patterns, as well as prediction of treatment outcomes.
Digital models, however, offer less time-consuming tool to address the issues
What are indications for mounting orthodontic casts on an articulator?
Determining CO-CR discrepancy (this is important because a study revealed that 34% of adolescents and 66% of adults present with CO-CR discrepancies greater than 2mm. however, there is no evidence to support the need to mount orthodontic models. The key assumption of articulator mounted models (that the relative position of the condyle to the occlusion will remain stable) is never met in growing patients
Mounted models are indicated in treatment planning and splint fabrication for orthognathic surgery patients, especially those undergoing a bimaxillary procedure, as well as recording excursive movements in interdisciplinary cases
Or if CO-CR shift is greater than 2mm is present
When are PA radiographs indicated?
If pano suggests pathologic condition
Assess periodontal status of adult patients
Evaluate root morphology and length in cases of root resorption
Evaluate PDL to rule out ankylosis
What is the main reason to take a posteroanterior ceph film? (Pt facing you)
Significant facial asymmetries who display large discrepancy of the border of the mandible in the lateral ceph as well as for evaluation of severe dental midline discrepancies
The horizontal symmetry of the mandible as well as angulation of its condyles and craniofacial anomalies can also be further explored with submentovertex cephs
What is the difference between anatomic and derived cephalometric landmarks?
Anatomic - represent actual anatomic structures
Derived - constructed points from anatomic structures
What is the SN plane?
Plane formed by connecting S point to N point. It represents a relatively stable anatomic structure known as the anterior cranial base. During growth and treatment, the SN plane remains relatively constant and can be used as a reference point to measure positional change of the maxilla and mandible
What is the Frankfort horizontal plane?
Formed by connecting porion to orbitale
The palatal plane is formed by connecting the ___ with the ___. It is usually near parallel to the ___
ANS
PNS
Frankfort horizontal
What is the mandibular plane?
A line drawn from the menton to gonion. The inferior border of the mandible may vary somewhat from the line, especially in cases with steep (high) MP angles.
What is the Y-axis?
The line from sella to gnathion. It is used as an indicator for facial growth tendency by measuring the angle formed between SGn and FH
The __ and ___ angles indicate the anterioposterior position of the maxilla and mandible relative to the cranial base
SNA
SNB
What is the ANB angle? What is the norm?
SNB - SNA. Forms a relative determination of the relationship of the maxilla to the mandible
Norm = 2 +/- 2
An ANB of 0 or less indicates a Class __ problem
3
What is VTO?
Visual treatment objective. It is a tool to predict desirable anteroposterior and vertical changes that will occur as a result of changes in the denture bases and tooth positions caused by growth, orthodontic treatment, and orthognathic surgery
Since the growth prediction is based on average changes, this method is more reliable in adults or late adolescents with little or no remaining growth.
Pretreatment and posttreatment cephs are superimposed on the ___ to evaluate changes in the maxilla
Lingual curvature of the palate.
In order to evaluate change in mandibular tooth movement as well as incremental growth of the lower jaw, where are the pretreatment and posttreatment cephs superimposed?
The mandibular composite is registered on the internal cortical outline of the symphasis with best fit on the mandibular canal
Where are pretreatment and posttreatment cephs superimposed in order to evaluate overall growth and treatment changes?
On the sella (SN line)
This technique is also used in orthognathic surgery cases to confirm growth cessation in the craniofacial region by superimposing two sequential cephs taken within a 6-12 month interval.
In order to confirm growth cessation. Two cephs are superimposed on the sella that are taken within a ___ interval. The lack of bony changes affirms that no further growth has taken place.
6-12 month
Orthodontic photons should be oriented to the ___
Frankfort horizontal plane
The NLA (nasolabial angle) is an excellent reference in the decision to ___
Extract teeth
How does the NLA (nasolabial angle) determine if extraction should be completed?
Acute NLA indicates that extraction would be beneficial to the facial profile. However, extraction in a patient with an obtuse NLA would be detrimental to facial esthetics.
Condylar resorption occurs in __-__% of patients who undergo orthognathic surgery
5-10%
True or false… the quality of the images of the TMJ with CBCT machines is comparable to conventional CTs but the image-taking is faster and less expensive, and provides less radiation exposure
True
What are some limitations to CBCT?
Although it is excellent in imaging hard-tissue structures and most soft-tissue components, it does not have the ability to precisely map out the muscles.
Soft tissue images do not capture the true color texture of skin
Long capture time (30-40s) during which involuntary muscle movements lead to inaccuracies in soft-tissue capture
