Ortho Flashcards

Question

What is the general treatment strategy for a DEEP OVERBITE? Often associated with? C2D2

Answer 1

EXTRUDE posterior teeth and allow rotation of mandible DOWNWARD. Maxillary molar extrusion via cervical headgear CLASS 2 DIVISION 2

Answer 2

Interferes with digit placement and tongue 👅 thrust Once INCISORS are in TRANSITION, 6-10 years of age. Planned for 6 MONTHS wear, HABIT usually CEASES in WEEKS.

Answer 3

SNA | Sella-Nasion-A point

Answer 4

Balance of face is determined by POSITION of MANDIBLE - uses FRANKFURT HORIZONTAL PLANE as a REFERENCE plane base (Porion to Orbital) - by that determines retro, pro, or orthognathism -FACIAL ANGLE: -Inside inferior angle -Uses intersection of NASION - POGONION plane to FH (Na - Pg) -Average angle: 87.8. +/- 3.5 > 87 = Prognathism < 87 = Retrognathism

Answer 5

MANDIBLE 1. Mand Primary Canine 2. Mand Primary 1st Molar 3. Mand Permanent 1st Premolar C D 4

Answer 6

In UNILATERAL CLASS 2 cases if you want to distalize one side. As the difference in outer bow length became greater, ⬆️ asymmetric effects increased. ⬆️ Greater distal force in the longer arm side was associated with greater lateral force towards the shorter arm side and more net yawing moment.

Answer 7

Opinion vary but this is an AAPD 2019 article. “There is general agreement between pediatric dentists and orthodontists that a frenectomy should not be performed before the PERMANENT CANINES ERUPT and that the operation should follow orthodontic closure of the space.”

Answer 8

Direction of MANDIBULAR growth. S-Gn (Sella turcica to Gnathion) to the FH plane. Gnathion - the most inferior point of the mandible in the midline. Average Angle: 59 degrees Angle greater > 59: class 2, vertical growth Angle smaller < 59: class 3, horizontal growth

Answer 9

CAUSATION: In a growing child, the UPPER ARCH can be UNDERDEVELOPED because of AIRWAY ISSUES or abnormal habits like thumb sucking. This can lead to an ABNORMAL CONTACT POINT high cuspids that interfere with the child’s ability to close properly and make contact with the posterior teeth. OBSERVE: (PBSP) the PRIMATE SPACING in the upper and lower anteriors. In a functional cross-bite, there is usually NO SPACING in the UPPER arch. **A skeletal Class III exhibits normal spacing.** **In a functional Class III, the bite is usually deep. In a skeletal Class III, it’s normal or end-to-end.** **Size of the maxilla. If narrow and high-vaulted, it tends to be functional.** **Mandibular plane angle. If the angle of the mandible appears parallel to the floor, this is indicative of a functional Class III.** TREATMENT: They don’t go away on their own. This is especially true of functional anterior (Pseudo Class III) cross-bites, and they are especially critical. You must correct them. Opting out makes you the causative factor behind a host of far-reaching, prohibitively expensive problems — most significantly the development of a permanent Class III dentofacial/mandibular abnormality. Treat it with a REMOVABLE APPLIANCE that will effectively jump the cross-bite by proactively directing the growth of the premaxillary segment and the teeth. You can alleviate the interference points, and allow the maxillary arch to once again encompass the lower arch. That done, the patient has an opportunity to return to normal function.

Answer 10

Leeway space is the SIZE DIFFERENTIAL between the PRIMARY POSTERIOR teeth (canine, first and second molars labeled C, D and E in the picture), and the PERMANENT canine and first and second premolar Per QUADRANT: Maxillary space of 1.5mm / 3mm total Mandibular space 2.5mm / 5mm total

Answer 11

EARLY MS: PRIMATE SPACES - Occurs about 6 years old - Incoming 6 year permanent molars - seen in @65% of patients (those who have primate space) LATE MS: - Exfoliation of the Second Primary molars - Occurs around 11 years old - seen in ALL patients

Answer 12

BONE GROWTH - FUNCTION OVER FORM Phenomenological description of bone growth. Soft tissues and capsules drive growth control. It proposes that "the origin, development and maintenance of all SKELETAL UNITS are SECONDARY, compensatory and mechanically OBLIGATORY RESPONSES to temporally and operationally prior demands of related functional matrices. bones do not grow but are grown, thus stressing the ontogenetic primacy of FUNCTION OVER FORM.

Answer 13

Flaring of the Mandibular Incisors

Answer 14

The most common cause of Class III malocclusions is excessive growth of the mandible. The molar position of these patients is referred to as mesio-occlusion, whereas the anterior relationship shows a negative overjet.

Answer 15

Posterior Crossbite

Answer 16

Displacement

Answer 17

MOST: Circummaxillary Sutures -Significant width increases in the intermaxillary, internasal, maxillonasal, frontomaxillary, and frontonasal sutures. -The greatest increase in width was recorded for the intermaxillary suture -The midpalatal suture showed the greatest increase in width at the central incisor level LEAST: Posterior (zygomatic interface) craniofacial structures. Frontozygomatic, zygomaticomaxillary, zygomaticotemporal, and pterygomaxillary sutures showed nonsignificant changes.

Answer 18

Class I The bite is normal, but the upper teeth slightly overlap the lower teeth. CLASS I MALOCCLUSION THE MESIOBUCCAL CUSP OF THE UPPER FIRST PERMANENT MOLAR OCCLUDES WITH THE MESIOBUCCAL GROOVE OF THE LOWER FIRST MOLAR, BUT LINE OF OCCLUSION IS INCORRECT BECAUSE OF MALPOSED TEETH, ROTATIONS OR OTHER DISCREPANCIES.

Answer 19

The most favorable morphologic factors for serial extraction include: - Class 1 malocclusion, a favorable morphogenetic pattern – one that does not change, - a flush terminal plane or a mesial step relationship of the primary second molars - minimum overjet and minimum overbite. - arch length discrepancy by 10mm or more - Permanent teeth congenitally absent

Answer 20

.25mm x 2 x 7 = 3.5mm

Answer 21

Infants’ palatal tissues are highly plastic and readily reflect the influences of sucking habits. Duration and intensity of pacifier sucking, as well as the size and shape of the pacifier, all are factors that contribute to the extent of the deformation. When the children were 12 months old, researchers found palatal tissue deformations in 96 percent of the pacifier-using children.

Answer 22

When upper jaw or dental arch is narrow patient needs to slide the jaw to one side in order to fit the teeth together. This shift is called functional shift. Expansion is required to address this issue.

Answer 23

Functional shift

Answer 24

The most favorable morphologic factors for serial extraction include: - Class 1 malocclusion, a favorable morphogenetic pattern – one that does not change, - a flush terminal plane or a mesial step relationship of the primary second molars - minimum overjet and minimum overbite. - arch length discrepancy by 10mm or more - Permanent teeth congenitally absent

Answer 25

.25mm x 2 x 7 = 3.5mm

Answer 26

Becomes LESS CONVEX with maturation | Downward And Forward

Answer 27

Point A Most concave point of anterior maxilla.

Answer 28

Direction of MANDIBULAR growth Angle Formed between the Sella (S) and Gnathion (GN) line and the FH plane. 59 degrees average ⬆️ Increase of Y-Axis is suggestive of greater vertical growth of the mandible. Angles increases ⬆️ with CLASS II facial patterns

Answer 29

X-Bite side: CLASS II | Non-X bite side: Class 1 or 3

Answer 30

More than 90% >90% of posterior crossbites in mixed dentition have a Functional Component.

Answer 31

A DECREASE ⬇️ of 2-3mm per QUADRANT | 4-6mm total arch

Answer 32

Intercanine width - The distance between the cusps of the canines ⬆️ Increase of MANDIBULAR = 2.4 Mean (0-5mm) ⬆️ Increase of MAXILLARY = 3.0 Mean ( 0-6.5mm)

Answer 33

Excessive Overbite Retroclined Central Incisors The maxilla was prognathic in both malocclusions. (I/II) A Class II skeletal pattern and reduced interincisal angle were common features of Class II/1 malocclusion, while a Class II skeletal pattern, increased interincisal angle, and skeletal deep bite were common features of Class II/2 malocclusion.

Answer 34

Mandibular Retrognathia A condition in which the lower jaw is set further back than the upper jaw, making it look like a person has a severe overbite.

Answer 35

BRADYFACIAL In Class II, Division 1 patients, with an excess overjet and proclined maxillary incisors.

Answer 36

MAX1 Loss of Maxillary 1ST Primary Molar AFTER 6 year Molar erupted

Answer 37

Middle to upper 1/3 of the crown

Answer 38

Mandibular Condyle

Answer 39

TRANSVERSE (Horizontal) - Least amount of change of any facial dimension - Facial Width - Greatest rate observed between 2-6 years - Lower face width (Bigonal) 85% complete by the time first molars erupt

Answer 40

Transverse (width) For both the maxilla and mandible, on average, growth in width is completed in advance of that in length, which ceases before growth in the vertical dimension. The transverse dimensions of the jaws and dental arches do not tend to alter during puberty, as growth in width is largely completed before the growth spurt. ***For males and females, growth of the MAXILLA in all dimensions is completed before that of the mandible**** Growth in length usually continues until 14–17 years in girls and 17–19 years in boys, while vertical growth may extend into the late teens in girls and into the twenties in boys.

Answer 41

PRIMARY: when it occurs early in life SECONDARY: when it is placed in the mixed dentition before or after eruption of the canines TERTIARY: when it is placed in the permanent dentition

Answer 42

Reciprocal Brings Mandibular molars forward with only a slight distalization of the Maxillary Molars. Can also cause elongation of Mandibular molars and Maxillary Incisors. Good for Brachyfacial and Mesofacial types

Answer 43

1. Level and Aligning 2. Correction of Molar Relationship and Space Closure 3. Finishing: Root paralleling, Torque of Incisors, Vertical Incisal relationship, Midline discrepancies, Tooth-Size discorepencies.

Answer 44

Both effective in Crossbite Correction Both forces are equivalent Quad: more flexible, great range of action, More bulky for reminder if finger habit is an issue.

Answer 45

1. After 6 year molars and Permanent Incisors have erupted up to the age of 10. 2. Used for children with a-p and Vertical maxillary deficiency. NOT for a combination on maxillary and Mandibular problems 3. Anchorage is obtained by force on the chin and forehead. Maxillary teeth should be splinted together as one unit. Forward force of maxillary teeth by elastics attached from teeth to appliance 4. Backward displacement of the Mandibular teeth, Forward displacement of the Maxillary teeth occur. (Not forward movement of the Maxilla)

Answer 46

Extractions in this order: 1. Primary Canine 2. Primary 1st Molar 3. Permanent 1st Premolar Interval between extractions is 6-15 months

Answer 47

Space loss after premature extraction of second primary molar in THREE weeks time frame. An increased amount of space loss in the maxillary arch may be due to significant MESIAL ROTATION of the first molars around the PALATAL ROOT. MESIO-LINGUAL Rotation Cortical plates anterior to the molar narrow after extraction, preventing the Molar from advancing directly, limiting its movement to rotation

Answer 48

Bilateral: Anterior open bite is a very common finding in patients with TMJ degenerative diseases. Unilateral: Posterior open bite associated with unilateral condylar resorption. Associated with mandibular shift to the affected side. The result is an anterior open bite associated with a posterior open bite on the contralateral side, with occlusal contact occurring only on the posterior region of the affected side

Answer 49

The main object of RME is to correct maxillary arch narrowness but its effects are not limited to the maxilla as it is associated with 10 bones in the face and head. Typically .5mm of lateral expansion per day is achieved by instructing the patient to activate the screw 1/4 turn in the morning and 1/4 turn at night. approximately 1mm per week is the maximum rate at which the tissue of the midpalatal suture can adapt. The main resistance to midpalatal suture opening is probably not the suture itself, but in the surrounding structures particularly the sphenoid and zygomatic bones. Anatomically, there is an increase in the width of the nasal cavity immediately following expansion thereby improves in breathing. The nasal cavity width gain averages of 1.9 mm, but can be as wide as 8 to 10 mm.

Answer 50

Improves Class III malocclusion through: 1. Posterior repositioning of the mandible 2. Redirection of mandibular growth backwards and/or downwards. 3. Closing of the gonial angle 4. Remodelling of the mandible and temporomandibular joint (TMJ) 5. Retardation of mandibular growth, and retroclination of mandibular incisors Pull directed Below the Condyle results in a downward and backwards growth on Mandible Pull directed Through Condyle if no Mandible angle change is desired.

Answer 51

Interstitial Growth - Interstitial growth is the LENGTHENING of the bone resulting from the growth of cartilage and its replacement with bone tissue. - occurs in hyaline cartilage of epiphyseal plate, increases LENGTH of growing bone.

Answer 52

Posterior Crossbite Equilibrate interference if possible, if not expand Maxilla.

Answer 53

Maxillary Deficiency

Answer 54

The curve, viewed from the front, that contacts the buccal and lingual cusps of the molars, being lower in the middle due to the lingual inclination of the long axes of the mandibular molars. Deepens Posteriorly

Answer 55

The curvature of the mandibular occlusal plane beginning at the premolar and following the buccal cusps of the posterior teeth, continuing to the terminal molar. The pull of the main muscle of mastication, the masseter, is at a perpendicular angle with the curve of Spee to adapt for favorable loading of force on the teeth. The long axis of each lower tooth is aligned nearly parallel to their individual arch of closure. It is of importance to orthodontists as it may contribute to an increased overbite. A flat or mild curve of Spee was essential to an ideal occlusion.

Answer 56

Where the connecting medium is hyaline cartilage, a cartilaginous joint is termed a synchondrosis. Sometimes, this is a temporary form of joint called epiphyseal growth plate, where the cartilage is converted into bone before adult life. They are immovable joints between bones of the cranial base.

Answer 57

NO There is no evidence for a cause-effect relationship between orthodontic treatment and temporomandibular disorders, or that such treatment might improve or prevent them.

Answer 58

Intramembranous Ossification The DIRECT CONVERSION of MESENCHYMAL tissue into bone is called intramembranous ossification. This process occurs primarily in the bones of the SKULL.

Answer 59

The upward and forward rotation of the maxilla during protraction is a major unwanted side effect.

Answer 60

Nasion to Menton N = nasion, the most anterior point of the FRONTONASAL suture in the midsagittal plane Me = menton, the most inferior point of the outline of the SYMPHASIS in the midsagittal plane

Answer 61

Resisting movement of a tooth or number of teeth. -Unplanned or unwanted tooth movement can have dire consequences in a treatment plan, and therefore using anchorage stop a certain tooth movement becomes important. Multi-rooted, longer-rooted, triangular shaped root teeth usually provide more anchorage than the single-rooted, short-rooted and ovoid rooted teeth.

Answer 62

Moyer’s Tanaka Johnson Ballard and Wylie

Answer 63

Nance’s Huckaba’s

Answer 64

Hixon and Oldfather Staley Kerberos

Answer 65

Passive prevention of rotation of the Maxillary first molars, holds them in place

Answer 66

When analysing the positions of the anterior teeth on the underlying bone and within the face, it is often obvious that the incisors are positioned well forward (regardless of overjet) in longer faces, often with more convex lip profiles. Equally, it is common for the incisors in shorter faces to appear relatively upright (even retroclined), often with more concave lip profiles. Vertical growth carries the chin downward, while anteroposterior growth carries it forward. The major sites of bony additions contributing to the facial growth include the facial sutures, maxillary alveolar processes, mandibular condyle and mandibular alveolar processes. If vertical growth increments at the facial sutures and the maxillary and mandibular alveolar processes exceed the condylar growth, the mandible would rotate backward. However, if growth at the condyle exceeds the total vertical growth at the facial sutures and alveolar processes, the mandible would rotate forward. These growth changes significantly alter the lower facial height and the position of chin horizontally and vertically.

Answer 67

Condylar head The primary growth centre of the mandible, grows in upward and backward directions with the resultant downward and forward displacements of the mandible and carries the mandibular dentition away from the vertebral column and cranial base.

Answer 68

Because of the need to avoid undue opening of the vertical relationship during treatment and to avoid increasing lip protrusion and convexity, extractions of premolar teeth (with or without enhanced vertical and anteroposterior anchorage) may be necessary in DOLICHOFACIAL patients, For negative discrepancies of more than 10 mm extraction is almost always required, preferably of first premolars because second premolar extraction is not suitable for large discrepancies

Answer 69

NO change in patient's facial height with bicuspid extraction.

Answer 70

FMA were found to be the most reliable indicators Frankfurt to Mandibular Plane Angle

Answer 71

Distal and intrusive movement of maxillary molars Mesial movement of mandibular molars Retrusion of maxillary incisors, Protrusion of mandibular incisors

Answer 72

Pogonion (Pog) Facial Plane: N-Pog

Answer 73

50% Baume reported two consistent morphologic arch forms of the primary dentition: Generalized spaces between the teeth were present (type I) Teeth were proximal contact without spacing (type II) Type 1 - 2/3 of kids Type 2 - 1/3 of Kids

Answer 74

Midpoint on the anterior margin of the Foramen Magnum Line that defines the cranium from the face.

Answer 75

Posterior Crossbite

Answer 76

Maxillary arch: ``` Central incisors (9.05 mm in males and 8.62 mm in females) Lateral incisors (7.07 mm in males and 6.95 mm in females). ``` Mandibular Arch: ``` Central incisors was lesser (5.68 mm in males and 5.55 mm in females) Lateral incisors (6.31 mm in males and 5.98 mm in females) ```

Answer 77

The Pendulum Appliance is used to distalize the molars for the correction of Class II. It produces a wide swinging arc of force from the midline of the palate to the upper molars producing a pendulum motion of the spring.

Answer 78

Acute Otitis Media

Answer 79

Quad Helix

Answer 80

Maxilla to Cranium: 82 degrees +/- 3 ``` + = Max prognathism - = Max retrognathism ```

Answer 81

The cephalocaudal trend, or cephalocaudal gradient of growth, refers to the pattern of changing spatial proportions over time during growth. (Head to body) By the time of birth the head has decreased to approximately 30% of total body length. In adults, the head represents approximately 6% of the body length.

Answer 82

True It completes a large portion of growth prenatally and during infancy and childhood.

Answer 83

True However, The timing of cessation of maxillary and mandibular growth may be closer in some individuals than clinicians assume.

Answer 84

FALSE The cranial vault (which encloses the brain) bones are formed by INTRAMEMBRONOUS ossification.

Answer 85

Endochondral Formation Endochondral bone formation can be found in the bones associated with joint movements and some parts of the skull base.

Answer 86

Of the sides with a flush terminal plane, FTP, relationship in the deciduous dentition, 56% progressed to a Class I molar relationship and 44% to Class II in the permanent dentition. The presence of a mesial step in the deciduous dentition indicates a greater probability for a Class I molar relationship and a lesser probability for a Class II molar relationship.

Answer 87

Buccal canine impaction is mostly associated with anterior transverse (dental and skeletal) deficiency and incisor impaction. Palatal impaction is mostly associated with small or missing lateral incisors, consistent with the guidance theory.

Answer 88

Herbst and Frankel

Answer 89

Excessive growth of the mandible. The molar position of these patients is referred to as mesio-occlusion, whereas the anterior relationship shows a negative overjet.

Answer 90

Normal occlusion: -The mesiobuccal cusp of the upper first molar occludes with the buccal groove of the lower first molar. - The mesial incline of the maxillary canine occludes with the distal incline of the mandibular canine. The distal incline of the maxillary canine occludes with the mesial incline of the mandibular first premolar. Class II malocclusion: -The mesiobuccal cusp of the upper first molar occludes anterior to the buccal groove of the lower first molar.  -The mesial incline of the maxillary canine occludes ANTERIORLY with the distal incline of the mandibular canine.  The distal surface of the mandibular canine is POSTERIOR to the mesial surface of the maxillary canine by at least the width of a premolar. Class III malocclusion: - The mesiobuccal cusp of the upper first molar occludes posterior to the buccal groove of the lower first molar. - Distal surface of the mandibular canines are mesial to the mesial surface of the maxillary canines by at least the width of a premolar . Mandibular incisors are in complete crossbite.

Answer 91

At the time the primary second molars are lost, both the maxillary and mandibular molars tend to shift mesially into the leeway space, but the mandibular molar normally moves mesially more than its maxillary counterpart. ***Late Mesial Shift*** This differential movement contributes to the normal transition from a flush terminal plane relationship in the mixed dentition to a Class I relationship in the permanent dentition.

Answer 92

Anterior displacement of the maxillary complex ( ⬆️ increase in SNA) Anterior displacement of upper teeth ➡️ Lingual inclination of lower incisors ⬅️ B ackward-downward rotation of the mandible 🔁 (increase in AFAI, SN.GoGn and FMS ⬆️) Decrease in SNB ⬇️

Answer 93

Nasal Index = Nasal Breadth / Nasal Height x100 Leptorrhine (long and narrow or Caucasian) Mesorrhine (medium or Asian) Platyrrhine (broad and flat or African)

Answer 94

80 degrees ``` + = Mand prognathism - = Mand retrognathism ```

Answer 95

A severe transverse discrepancy, when all buccal cusps of the mandibular molars are telescoped within the lingual cusps of the maxillary molars.

Answer 96

Basion - Nasion (BN)

Answer 97

Down and forward

Answer 98

Occlusal Interference

Answer 99

FMA FMA: the angle between the Frankfort horizontal (orbitale – porion) and mandibular plane.

Answer 100

The lip bumper appliance is designed to gain space and make room for your mandibular teeth. It does this by moving your molars toward the back of your mouth or allowing the front teeth to drift forward. - Can cause the first molar to tip distally - Increase in the arch width seen in the intercanine and deciduous intermolar and premolar distances. - Incisor proclination

Answer 101

Mandibular Condyle

Answer 102

Flaring of mandibular incisors

Answer 103

``` Fixed: Class III elastic with skeletal anchorage -Skeletal effect Removable Modified Balters’ Bionator III -Dental effect Frankel III -Skeletal/dental ``` ``` Removable: Reverse twin block -Dental effect Eschler/progenic appliance (removable mandible retractor) -Dental effect Double-piece corrector -Dental effect Tandem appliance -Skeletal/dental ``` Extra-Oral Chin cap - Skeletal Face mask - Skeletal Headgear for mandibular arch - Skeletal/dental

Answer 104

Restricts growth of Mandible

Answer 105

High: Anterior Open Bite Low: Deep Bite

Answer 106

N-pogonion

Answer 107

NASION Facial Plane: Nasion-Pogonion Cranial Base: Nasion-Sella