Lecture 11

Question 1

INTEGRINS

Answer 1

TRIGGER SIGNAL TRANSDUCTION TO CELL INTERIOR

(1) TRANSMEMBRANE RECEPTORS THAT BRIDGE CELL-CELL AND CELL-ECM INTERACTIONS
(2) ACTIVATE TRANSCRIPTION FOR REGULATION OF CELL CYCLE AND CELL SHAPE
(3) DETECT ECM COMPOSITION AND MECHANICAL STATUS

Question 2

WNT PATHWAY EXAMPLES

Answer 2

(1) ESSENTIAL CANONICAL WNT SIGNALING PATHWAY - (MOST COMMON)
WNT BINDS TO FZ CELL SURFACE PROTEIN => TRANSDUCTION OF B-CATENIN AND ITS ACTIVATION => STIMULATION TO RELOCATE TO NUCLEUS WHERE IT ACTS ON TcF7 TO STIMULATE TRANSCRIPTION
PATHWAY CAN BE INHIBITED BY LITHIUM => B-CATENIN DEGRADATION
(2) WNT SIGNALING INDUCES EPITHELIAL-MESENCHYMAL TRANSITION (EMT) AND MIGRATION
EPITHELIAL CELLS LOSE CELL POLARITY AND CELL-CELL ADHESION INDUCED BY WNT SIGNALING - INVOLVES DOWN REGULATION OF CADHERINS TYPE I TRANSMEMBRANE PROTEINS
ALLOWS TRANSITION INTO MESENCHYMAL STEM CELLS THAT ARE NO LONGER HELD IN PLACE
CELLS DETACH AND BECOME MIGRATORY AND INVASIVE

Question 3

REMODELING OF PERIODONTIUM ON TENSION SIDE

Answer 3

1. ) PDL FIBROBLASTS UNDER STRAIN => IL-1 AND IL-6
2. ) IL-6 STIMULATES MMP AND INHIBITS TISSUE INHIBITOR OF METALLOPROTEINASE SYNTHESIS BY PDL
3. ) VASCULAR ENDOTHELIAL GF PRODUCED BY MECHANICALLY ACTIVATED FIBROBLASTS => ANGIOGENESIS
4. ) DEGRADATION OF ECM BY MMPs => CELL PROLIFERATION AND CAPILLARY GROWTH
5. ) PDL CELLS, OSTEOBLASTS AND BONE LINING CELLS SYNTHESIZE STRUCTURAL AND OTHER MATRIX MOLECULES

Question 4

REMODELING OF PERIODONTIUM ON COMPRESSION SIDE

Answer 4

1. ) PDL CELLS UNDER COMPRESSIVE STRAIN => IL-1 AND IL-6
2. ) IL-1 AND IL-6 ACT LOCALLY AND UPREGULATE RANKL AND MMP IN PDL AND OSTEOCLASTS
3. ) RANKL STIMULATES FORMATION AND FUNCTION OF OSTEOCLASTS FROM PRECURSOR CELLS => DEGRADATION OF BONE SURFACE
4. ) DEFORMATION OF ALVEOLAR BONE UPREGULATES MMPs EXPRESSION BY OSTEOCLAST ADJACENT TO BONE SURFACE

Question 5

SUSTAINED LIGHT PRESSURE PHYSIOLOGICAL RESPONSES

Answer 5

1. ) 3-5S - ALTERATION IN BLOOD FLOW
2. ) MINUTES - O2 LEVELS CHANGE => INCREASED PROSTOGLANDIN AND CYTOKINES
3. ) HOURS - HISTOLOGICAL CHANGE IN PDL CELLS = INCREASED cAMP
4. ) 2-DAYS - OC/OB ACTIVITY => FRONTAL RESORPTION

Question 6

SUSTAINED HEAVY PRESSURE PHYSIOLOGICAL RESPONSES

Answer 6

1. ) MINUTES - BLOOD FLOW STOPS
2. ) HOURS - CELL DEATH FROM COMPRESSION
3. ) DAYS - OC/OB ACTIVITY BEGINS AND REMODELING OF ADJACENT MARROW SPACES
4. ) WEEKS - UNDERMINING RESORPTION REMOVES DEAD BONE => LOSS OF VITALITY OF LOCALIZED PDL AREAS

Question 7

ANCHORAGE TECHNIQUES

Answer 7

USE LARGE GROUP OF TEETH TO PULL AGAINST A SMALLER GROUP OF TEETH
USE OF A SPECIAL APPLIANCE (CAN BE USED TO PROVIDE ANCHORAGE)
I.E. ELASTICS/HEADGEAR - USED TO PREVENT UNWANTED TOOTH MOVEMENT
SKELETAL ANCHORAGE TECHNIQUES - UNDERLYING JAW BONES USED FOR ANCHORAGE (DENTAL IMPLANTS)

Question 8

FACTORS AFFECTING ANCHORAGE

Answer 8

OF ROOTS
SHAPE, SIZE AND LENGTH OF EACH ROOT
(I.E. MULTIROOTED > SINGLE ROOTED) (I.E. LONGER ROOTED > SHORTER ROOTED) (I.E. TRIANGULAR SHAPED ROOT > CONICAL OR OVOID ROOT) (I.E. LARGER SA > SMALLER SA)

Question 9

TYPES OF ANCHORAGE

Answer 9

SIMPLE - RESISTANCE TO TIPPING
STATIONARY - RESISTANCE TO BODILY MOVEMENT
RECIPROCAL - 2+ TEETH OMVING IN OPPOSITE DIRECTION AND PITTED AGAINST EACH OTHER BY THE APPLIANCE (I.E. CLOSURE OF A CENTRAL DIASTEMA)

Question 10

ANGLES CLASSIFICATIONS OF MALOCCLUSION

Answer 10

CLASSIFICATIONS BASED ON RELATIVE POSITION OF MAXILLARY FIRST PERMANENT MOLAR
LOOK AT THE SAGITTAL DENTAL RELATIONSHIP

Question 11

CLASS I

Answer 11

MESIOBUCCAL (MB) CUSP OF MAX. 1ST PERMANENT MOLAR OCCLUDES WITH THE MB GROOVE OF THE MANDIBULAR 1ST MOLAR
MESIAL INCLINE OF MAXILLARY CANINE OCCLUDES W/ THE DISTAL INCLINE OF THE MANDIBULAR CANINE
MESOGNATHIC = NORMAL, STRAIGHT FACE PROFILE W/ FLAT FACIAL APPEARANCE

Question 12

CLASS II

Answer 12

MB GROOVE OF MANDIBULAR 2ST MOLAR IS DISTALLY POSITIONED WHEN IN OCCLUSION W/ MB CUSP OF MAXILLARY 1ST PERMANENT MOLAR
MESIAL INCLINE OF MAXILLARY CANINE OCCLUDES ANTERIORLY W/ THE DISTAL INCLINE OF THE MANDIBULAR CANINE
RETROGNATHIC = CONVEX FACIAL PROFILE RESULTING FROM A SMALL MANDIBLE/LARGE MAXILLA

Question 13

CLASS III

Answer 13

MB CUSP OF MAXILLARY 1ST PERMANENT MOLAR OCCLUDES DISTALLY TO THE MB GROOVE OF MANDIBULAR 1ST 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
PROGNATHIC = CONCAVE FACE PROFILE W/ A PROMINENT MANDIBLE ASSOCIATED W/ CLASS III MALOCCLUSION

Question 14

CROSSBITE

Answer 14

TEETH HAVE A MORE BUCCAL/LINGUAL POSITION THAN CORRESPONDING ANTAGONIST TEETH IN THE UPPER OR LOWER DENTAL ARCH

Question 15

INDICATIONS FOR EXPANSION OF DENTAL ARCHES

Answer 15

UPPER PROTRUSION - OVERJET
SPACING/CROWDING PROBLEMS
MISPLACED MIDLINE
OPEN BITE
OVER BITE
UNDER BITE
CROSS BITE
ROTATION

Question 16

PALATAL EXPANSION (RAPID MAXILLARY EXPANSION)

Answer 16

USUALLY => DIASTEMA AT THE MAXILLARY INCISORS
CLOSES NATURALLY OVER TIME
MOST SUCCESSFUL ON CHILDREN 5 < X < 16 Y.O.
ADULTS MAY ONLY NEED DENTAL AND NOT PALATAL EXPANSION

Question 17

EXPANDING USING ORTHODONTIC/ORTHOPEDIC FORCE

Answer 17

ORTHODONTIC FORCE = TEETH ALONE ARE SUPPOSED TO MOVE

ORTHOPEDIC FORCE = CHANGE IN THE STRUCTURE OF MANDIBLE/MAXILLA

Question 18

DEVELOPMENTAL STAGES OF PALATAL SUTURE

Answer 18

INFANTILE = BROAD AND Y-SHAPED
JUVENILE = MORE WAVY
ADOLESCENT = INCREASED INTEGRATION