DIAGNOSTIC PROCEDURES
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INDIAN DENTAL ACADEMY Leader in continuing dental education www.indiandentalacademy.com
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CONTENTS
INTRODUCTION CASE HISTORY ATHROPOMETRY CRANIOMETRY PHOTOGRAPHIC ANALYSIS CONTOUR PHOTOGRAPHY STEREOPHOTOGR AMMETRY
STUDY MODELS HOLOGRAMS OCCLUSOGRAMS PHOTOCOPYING E-MODELS VTO DIGIGRAPH CBCT
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Examination of postural rest position, TMJ Orofacial dysfunction Radiographic examinations Conventional tomography Computed tomography Ultrasonography
Anthrography FEM Palatography Cineradiography EMG Bone scanning Lazor scanning Videocephalometry Electronic thermography MRI
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INTRODUCTION “
The first step towards cure is to know, what the disease is………..” www.indiandentalacademy.com
DIAGNOSIS SOME
DIAGNOSIS ARE EASY,MANY ARE DIFFICULT AND FEW ARE IMPOSSIBLE-YET ALL ARE IMPORTANT,FOR DIAGNOSIS IS THE TRUMP FACTOR IN PROVIDING ORTHODONTIC CARE.
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GOAL To classify malocclusion ,the patient presents with. ď‚Ą Treatment planning. ď‚Ą
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MEANING
STRANG: “There is nothing
complicated about making a diagnosis in orthodontia, for the moment one has detected a deviation from normal occlusion and so determines that there is malocclusion, the diagnosis is complete.”
ANGLE: Normal occlusion, favorable function& acceptable dentofacial esthetics represented an identity. This process could be called the TRADITIONAL APPROACH. www.indiandentalacademy.com
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CASE,HELLMAN &SIMON: Orthodontic diagnosis required a deeper understanding of the orthodontic problem. The concepts of dental and skeletal problem can be credited to these men. RATIONAL APPROACH
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MOORREES & GRON: Dental, skeletal, muscular factors and the somatic and emotional development of an individual. They also considered personal and societal factors. This view is called the OVERALL DIAGNOSIS. www.indiandentalacademy.com
DEFINITION
THOMAS RAKOSI: The recognition and systematic designation of anomalies, the practical synthesis of the findings, permitting therapy to be planned and indication to be determined, thereby enabling the doctor to act. Orthodontic diagnosis requires a broad overview of the patient’s situation. www.indiandentalacademy.com
RECOGNISING THE PROBLEM
FORMULATING THE PROBLEM
CARRYING THE NECESSARY EXAMINATIONS
INTERPRETATION OF THE RESULTS
DIAGNOSIS
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COMPREHENSIVE DIAGNOSIS
Orthodontic diagnosis should be routinely based on various methods of examination. The COMPREHENSIVE DIAGNOSIS should be a summary of the most important facts and should not take insignificant secondary symptoms into account.
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ď‚Ą
Orthodontic diagnosis can be referred to as a diagnostic process.
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DIAGNOSIS &TREATMENT PLANNING
Recognize the various characteristics of malocclusion and dentofacial deformity. Define the nature of the problem including the etiology if possible. Design a treatment strategy based on specific needs and desires of the individual. Present the treatment strategy to the patient in such a way that the patient fully understands the ramifications of the treatment. www.indiandentalacademy.com
PROBLEM ORIENTED APPROACHDIAGNOSIS
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DIAGNOSTIC AIDS
ESSENTIAL:
Case history Clinical examination Study models RADIOGRAPHS IOPA’S Cephalograms OPG Bitewing Facial Photographs
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NONESSENTIAL
Specialized radiographs EMG activity of muscle Hand wrist radiography CT scan MRI Endocrine tests Basal metabolic rate Vitality test Biopsy
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CASE HISTORY
Medical
Dental
Family
Patient
Prenatal
Postnatal
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Patient
Birth
CASE HISTORY
PATIENT HISTORY PERSONAL DETAILS: NAME AGE & DATE OF BIRTH SEX ADDRESS & OCCUPATION
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PRENATAL PERIOD
MATERNAL Tetracycline stains on teeth Viral infection and cleft formation INTRAUTERINE MOULDING :Pressure during fetal growth distorts the developing face. e.g. PIERRE ROBIN SYNDROMME. Uterine posture Fibroids of the mother Amniotic lesions www.indiandentalacademy.com
TERATOGENS
ASPIRIN
Cleft lip & palate
CIG.SMOKE
Cleft lip & palate
DILANTIN
Cleft lip & palate
ETHYL ALCOHOL
Mid face deficiency
VALIUM
Cleft lip & palate
VIT.D EXCESS
Premature suture closure.
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Maternal diet Metabolic differences: “Cephalometric study of children with various endocrine diseases” A.J.O 59:362-375 1971.These appear to be unlikely causes. (SPEIGER et al) Injury to the mother Drug induced deformities: Thalidomide German measles www.indiandentalacademy.com
BIRTH HISTORY
Forceps deliveries injuries of the TMJ. Pressure Ankylosis Mandibular growth retardation.
BREECH DELIVERY
VOGELGESICHT: Inhibited growth of the mandible due to ankylosis of the T.M.J
Cerebral Palsy
Delivery induced deformation of the upper jaw. www.indiandentalacademy.com
POST NATAL HISTORY
Type of feeding: Breast, Bottle Advantageous: Activates jaw muscle Increases functional loading Moves mandible anteriorly Compensates for the physiologic retruded jaw position at birth. The child's sucking reflex is satisfied. Fewer chances of habits. www.indiandentalacademy.com
CONSISTENCY OF FOOD: SOLID:MASSETER CHEWER
High functional load –strong bony framework. Food-ground Dec. teeth abraded Lower arch displaced forward. 1st molars positioned favorably. Decreased overbite.
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NON SOLID:TEMPORALIS CHEWER
Food chewed superficially. Low functional load: incomplete development of framework. Minimal abrasion of teeth. 1st molars unstable Lower arch not displaced anteriorly.
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HABITS: Duration, frequency & intensity. Duration is the most imp.
TRAUMA:# of the condyle.
PRIMARY FAILURE OF ERUPTION: Lead to posterior open bite.
POSTURE: Head: Forward, Chin extended associated with a long face.
Head backward: Short face
Extensive scar formation
MILWAUKEE BRACES www.indiandentalacademy.com
CHIEF COMPLAINT
Recorded in pt’s. Own words. Mention what the pt. feels he/she is suffering from. Pt’s. perception. What is important for the patient. Why has the pt. come? Esthetics or impaired function.
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MEDICAL HISTORY
H/O hospitalization :Tonsillectomy & adenoidectomy. Trauma Heart ds., rheumatic fever, murmur Blood transfusion: HIV, hepatitis. Diabetes mellitus Arthritis/osteoporosis Poliomyelitis Muscle dysfunction Hypothyroidism: retained dec. teeth, delayed eruption, abnormal resorption. www.indiandentalacademy.com
DRUG HISTORY
Reveal systemic ds. Epileptic pt. takes dilantin -anticonvulsant drug-gingival hyperplasia-impede tooth movement. Steroids: decreases resistance to infection-difficulty in tolerating orthodontic appliances. Osteoporosis: resorption inhibiting drugs (prostaglandin inhibitors) www.indiandentalacademy.com
ALLERGY Latex sensitivity: gloves, elastics ď‚Ą Nickel sensitivity: wires & brackets. If sensitive titanium brackets or ceramic brackets may be used. ď‚Ą
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DENTAL HISTORY
Past dental history will help in assessing the pts. or parents attitude. Indicator of pt’s susceptibility towards Pdl. ds. or caries. H/O traumatic injury to teeth: orthodontic treatment exacerbate periapical symptoms that are already present. Dental health awareness www.indiandentalacademy.com
PSYCHOSOCIAL HISTORY
Social & behavioral history. Difficult to obtain; Parent is reluctant to speak. Emotional problems are suspected when :Thumb sucking, poor progress in school, sleep walking in a young child, enuresis in an older child. www.indiandentalacademy.com
SCHOOL PROGRESS
To know about learning disability. If present modify approach. Pts have short attention span To much of detailed information about treatment can produce anxiety. Reduce responsibility of the patient.
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MOTIVATION
EXTERNAL OR INTERNAL External: supplied by pressure by another individual. Internal: comes from within based on his or her own assessment of the situation. A child or an adult who feels that the treatment is being done for him will be a more receptive patient than one who feels that the treatment is being done to him.
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EXPECTATION
HIGH, MODERATE, LOW What patient expects from treatment is related to the type of motivation. If the patient expects social adjustment problems to be solved after treatment then he or she is a poor candidate for orthodontic treatment. www.indiandentalacademy.com
COOPERATION
Problem with the child than the adult. Factors important are: The extent to which the child sees the treatment as benefit as opposed to something else he or she is required to undergo. The degree of parental control. A rebellious child with ineffective parents is likely to become a problem. www.indiandentalacademy.com
FAMILY / GENETIC HISTORY
Any siblings of the patient require any orthodontic treatment. Parents ever underwent orthodontic treatment. The tissues primarily affected are: NEUROMUSCULAR SYSTEM TEETH: Size, shape , number, mineralization, path of eruption, position of tooth germ, sequence of eruption. www.indiandentalacademy.com
BONE
SIZE: Hereditary micrognathia or macrognathia. SHAPE: Asymmetries – Crouzon’s disease, cleidocranial dysostosis. LOCATION: Prognathism, retrognathism. Class 2 div.2,Mand.prog.,bimax. protrusion, skeletal open bite, skeletal mand. retrognathism. www.indiandentalacademy.com
SOFT TISSUE Facial clefts Microstomia Anomalies of the frena Ankyloglossia
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CLINICAL EXAMINATION
EXTRAORAL GENERAL PHYSICAL DEVELOPMENT To assess the amt. of growth that has occurred & the potential of future growth that remains. Best results-good growers-amt., rate, direction, pattern that facilitates treatment. Modifiability of a problem & treatment prognosis are strongly influenced by growth. www.indiandentalacademy.com
PHYSICAL GROWTH EVALUATION
Whether the child has recently grown rapidly? Whether there is a change in the size of the clothes? Whether there are signs of sexual maturation? Whether there is a change in the voice? www.indiandentalacademy.com
GENERAL BODY TYPE(PHYSIQUE)
ASTHETIC: Thin physique, possess narrow dental arches. PLETORIC: Obese, have large square dental arches. ATHLETIC: Normally built, being neither thin nor obese. Have normal sized dental arches.
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BODY BUILD
SHELDON ECTOMORPHIC: Tall & thin physique. Grow more slowly & reach the pubertal growth spurt later. MESOMORPHIC: Average physique. ENDOMORPHIC: Short & obese. www.indiandentalacademy.com
HEIGHT & WEIGHT
Clue to the physical growth
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GAIT ď‚Ą ď‚Ą
It is the way the person walks. Abnormalities of gait are associated with neuromuscular disorders.
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POSTURE Poor postural conditions either lead to malocclusion or accentuate it. ď‚Ą A stoop shouldered child with the head hung, chin rests on the chest: Mandibular retrusion. ď‚Ą
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CEPHALIC EXAMINATION
The shape of the head is assessed. MARTIN & SALLER (1957): DOLICOCEPHALIC Long & narrow head. Narrow dental arches.
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MESOCEPHALIC
Average shape of head. Possess normal dental arches.
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BRACHYCEPHALIC
Broad & short head. Broad dental arches.
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CEPHALIC INDEX Based on anthropometric determination of the max. width of the head and max. length. ď‚Ą Cephalic index: Max. skull width Max. skull length Dolicocephalic: -75.9 Mesocephalic:76-80.9 Brachycephalic:81-85.4 Hyperbrachycephalic:85.5ď‚Ą
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QUADRATE CAPUT ď‚Ą
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Square deformity of the skull in rickets caused by the protuberances of the frontal and parietal bones.
CRANIOMETRY
Used to study growth. Involves measurement of the skulls found amongst the human skeletal remains. Adv: Precise measurement can be made on dry skulls. Disadv: The growth study is crosssectional. www.indiandentalacademy.com
FACIAL EXAMINATION
“Beauty/esthetics lies in the eyes of the beholder” Goal: Detect disproportion. Done with patient either standing in a relaxed manner or seated in a straight chair. The upright position enables to assume a NHP.
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FRONTAL VIEW (FACIAL FORM)
MARTIN & SALLER(1957) EURYPROSOPIC:B road & short face Apical base is wide in trans. dimension. Dental crowding is confined to coronal part, coronal crowding. Trans. expansion indicated.
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LEPTOPROSOPIC/HYPERLEPTOPROSO
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Long & narrow face. Reduced bizygomatic width. Narrow apical base in trans. dimen. Extraction therapy should be done incase of crowding. Reduced overbite. Steep mand. Plane.
MORPHOLOGIC FACIAL INDEX Morphologic facial height Bizygomatic width Hypereuryprosopic:-78.9 Euryprosopic: 79-83.9 Mesoprosopic:84-87.9 Leptoprosopic:88.0-92.9 Hyperleptoprosopic:93.0 ď‚Ą
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SYMMETRY ď‚Ą
The width of the base of the nose should be approx. same as the inter inner canthal distance, while the width of the mouth should be approx. the distance b/w the irises.
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GROSS FACIAL ASYMMETRIES
Congenital defects Hemifacial atrophy/hypertrophy Unilateral condylar ankylosis and hyperplasia.
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ANTHROPOMETRY
Enables measurement of skeletal dimensions on living patients. Establishes facial proportion. Various landmarks established in the studies of dry skulls are measured in living individuals by using soft tissue points overlying the bony landmarks. Measurement made with st. or bow calipers. www.indiandentalacademy.com
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ADVANTAGES
Allows to follow the growth of an individual directly, making the same measurement repeatedly at diff. times. Assessment of general pattern of craniofacial growth.
DISADVANTAGES
Soft tissue introduces variation.
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FARKAS ANTHROPOMETRIC STUDY
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MIDLINE DEVIATIONS
Dentoalveolar midline shift in the upper arch. The contat of the upper CI does not coincide with the center of the philtrum.
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MIDLINE SHIFT IN THE LOWER ARCH ď‚Ą
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Dentoalveolar: Results from tooth migration. The mental spine of the mandible coincides with the midsagittal plane of the skull only contact pt. of the incisors is deviated.
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SKELETAL DEVIATION OF THE MANDIBULAR MIDLINE ď‚Ą
The skeletal midline of the mandible & the contact pt. of the lower incisors is deviated.
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LATERAL VIEW-PROFILE
“Poor man’s cephalometric analysis” Goals: To establish whether the jaws are placed proportionately in the anteroposterior plane of space. 2 lines are drawn: one from the bridge of the nose to the base of the upper lip & the 2nd one extending from that pt. downward to the chin. These line segments should form a straight line. Angle: CONVEX PROFILE: Skeletal class2 CONCAVE PROFILE: Skeletal class 3 www.indiandentalacademy.com
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DIVERGENCE OF FACE
MILO HELLMAN Defined as an anterior or posterior inclination of the lower face relative to the forehead. Profile: straight: does not matter whether it slopes anteriorly (anterior divergence) or posteriorly (posterior divergence) Divergence does not indicate facial or dental disproportion whereas profile concavity or convexity does indicate disproportion, but does not by itself indicate which jaw is at fault. www.indiandentalacademy.com
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EVALUATION OF LIP POSTURE &INCISOR PROMINENCE
Teeth protrude: The lips are prominent & everted. The lips are separated at rest by more than 3-4mm. Excessive protrusion: Revealed by prominent lips that are separated when relaxed, so that the pt. must strain to bring the lips together, RETRACTION of the teeth alone tend to improve lip function & facial esthetics. But if the lips are prominent & close over the teeth without strain, the lip posture is largely independent of tooth position. In these individuals retracting the incisors www.indiandentalacademy.com would have little effect on the lip function.
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The lip posture & prominence should be evaluated by viewing the profile with the pts. lip relaxed. The upper lip is related to a true vertical line passing through the soft tissue pt. A & the lower lip is related to a true vertical line passing through the soft tissue pt.B.
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lips fall forward from the line-PROMINENT Lips fall backward from the lineRETRUSIVE Both lips are prominent & incompetentAnterior teeth are protrusive.
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EVALUATION OF THE VERTICAL FACIAL PROPORTION & THE MANDIBULAR PLANE ANGLE
A well proportioned face can be divided into vertical thirds. This is called as the LAW OF THIRDS
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INCLINATION OF THE MANDIBULAR PLANE
Steep: open bite, long ant. facial ht. Flat: Deep bite, short ant. facial ht. Visualized by placing a finger or a mirror handle along the lower border.
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PHOTOGRAPHIC RECORDS
SANDLER & MURRAY “ Clinical photography in orthodontics” J.C.O 97
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EXTRA ORAL VIEWS- FRONTAL ď‚Ą
ď‚Ą
Assesses major disproportions & asymmetries of the face. The camera should be placed perpendicular to the facial midline during exposure.
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PHOTOGRAPHIC ANALYSIS-FRONTAL PLANE-ASSESS SYMMETRY
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Vertical reference plane: skin nasion to the subnasal pt. Upper horizontal plane: Bipupillary plane. Lower horizontal plane: parallel to the bipupillary plane through the stomion. Mild degree of asymmetry occurs b/w the 2 sides of the face.
FRONTAL DYNAMIC SMILE ď‚Ą
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Demonstrates the amount of incisor & gingival display while the pt. smiles. Reduction of large overjets or overbites can greatly enhance the pts. smile.
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CLOSE UP IMAGE OF POSED SMILE ď‚Ą
For the analysis of the smile relationship.
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THREE QUARTER EXTRA ORAL VIEW- 45 DEGREE PHOTOGRAPH
Mid face deformities.
Nasal deformities
Assessment of the way the pts. Face is viewed by others.
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THE PROFILE
Helpful since the profile of the pt. can change during orthodontic treatment. Left profile-routine diagnosis Rt. profile-facial asymmetry
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CLASSIFICATION OF THE FACIAL PROFILE-A.M SCHWARZ-1958
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Eye ear plane (Frankfort horizontal plane) Skin Nasion perpendicular Orbital perpendicular according to Simon.
JAW PROFILE FIELD: Lies b/w both the perpendiculars. Children:13-14mm wide Adults:15-17mm wide Ideal average value face: the subnasal pt. touches the skin nasion perpendicular. The soft tissue chin point: lies in the center of the “jaw profile field”. It is the most ventral point of the soft tissue part of the chin. The skin gnathion (the most inferior chin pt.) lies on the orbital pointer. www.indiandentalacademy.com
NINE POSSIBLE PROFILE VARIANTSA.M SCHWARZ –ST. JAW PROFILE
Average face: The subnasale lying on the skin nasion perpendicular. Anteface: Subnasale lying in front of the skin nasion perpendicular. Retroface: Subnasale lying behind the skin nasion perpendicular.
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BACKWARD SLANTING PROFILE
The soft tissue pogonion is displaced too far posteriorly relative to the subnasal point. Backward slanting average face Backward slanting anteface Backward slanting retroface.
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FORWARD SLANTING PROFILE
The soft tissue of the chin is too far anterior in relation to the subnasal pt. Forward slanting average face Forward slanting anteface Forward slanting retroface
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STEREO PHOTOGRAMMETRY
Use of stereophotogrammetry was first reported by Thalmaan-degen in 1964. It involves photographing a three dimensional object from 2 different coplanar views in order to derive a 3 dimensional reconstruction of an image. The landmarks are identified in 3 dimensions to allow tracking of relative changes in the location of the landmarks as a result of growth, development, mandibular movement, injury, skeletal malformation & treatment. Captures the human face well. www.indiandentalacademy.com
A 3 dimensional X-ray stereometry is produced from paired coplanar images in order to allow accurate merging of 3 dimensional coordinate data from head films, study casts & facial photographs. Two photographs are taken with 2 semimetric cameras, which form a STEREOPAIR. The cameras are mounted on a frame with a dist. Of 50cm b/w them,& positioned convergently with an angle of 15 degrees. With the use of a analytical plotter & a stereopair a 3 dimensional image of an object is created. ADV.-Noninvasive By combining X-rays with the principles of stereophotogrammetry changes in the bone density can be tracked in 2 dimensions. Gives a good impression of the surface of the object. www.indiandentalacademy.com
ORTHODONTIC APPLICATIONS
“Method
for quantifying facial asymmetry in 3 dimensions using stereophotogrammetry” Angle orthod. Vol.65 No.3 1995 Is a 3 dimensional method to quantify facial morphology for the purpose of diagnosis. Detect changes in the facial morphology during growth & development. Detects asymmetries. Assessing facial contour, surface appearance of the face. Evaluation of treatment results. Quantitative data on facial proportions & profile indices. The life like 3D model of the pt. can be rotated enlarged, measured in 3 dimensionswww.indiandentalacademy.com as required for diagnoses.
CONTOUR PHOTOGRAPHY
Uses grid projections during exposure resulting in standardized contour lines on the face. It is a light scanning technique for three dimensional facial measurement, in which telecentric lences are used to eliminate divergence. Suited for smoothly contoured surfaces. Used as an alternative to stereophotogrammetry for three dimensional facial measurement. www.indiandentalacademy.com
USES
DISADVANTAGES
Records the shape of the face. Facial symmetry Changes due to growth. To study changes following surgery. Profile
Difficulties are encountered if a surface has sharp features. Great care is needed in positioning the head since small change in the head position produces a large change in the pattern.
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SOFT TISSUE EXAMINTION
EXTRA ORAL Forehead
INTRA ORAL
Lips & cheek frenal attachments
Nose Lips
Gingiva
Chin
Palatal & oral mucosa
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EXTRA ORAL-FOREHEAD ď‚Ą
The ht. of the forehead (dist. From hairline to glabella) should be 1/3rd of the entire face ht.& is as long as the midthird (dist. of the glabella to the subnasal line)& the lower third (dist. From subnasale to menton.
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ď‚Ą
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Relationship of the forehead is considered to the bizygomatic width. It can be described as Narrow or wide. The lateral forehead contour or the slope of the forehead could be Flat, protruding, steep. The dental bases are more prognathic than incases with a flat forehead.
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NOSE Nasal growth & its contribution to profile. Can be in both vertical & anteroposterior projection. More in vertical. Males>Females-10-16 yrs. The center of this spurt at the age of 12yrs. Females-spurt for nasal growth12yrs.
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Genecov et al “Development of nose & soft tissue profile” Angle orthod 60(8)191,1990 stated that: Nasal projection in females remains virtually constant from age 12.Thus a orthodontist evaluating a pt. of class 2 at this age could expect only a reasonable increase in the nasal projection. There is a sharp peak in the nasal tip projection b/w ages 9&10 Nasal projection in males continued from ages 12-17yrs.Thus any procedure that results in upper lip retraction in combination with anterior nasal growth would produce less than optimal relationship b/w the lips & the nose www.indiandentalacademy.com
SIZE OF THE NOSE
The vertical nasal length measures 1/3rd of the total facial ht. (dist. From hairline to gnathion) The relationship b/w vertical & horizontal length of the nose is 2:1. Microhinic type: The root of the nose is high, short nasal bridge & an elevated tip.
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NASAL
CONTOUR:
Straight, convex, crooked
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SHAPE & WIDTH OF NOSTRILS:
Should be assessed since they indicate impairment of nasal breathing. Nostrils: oval & bilaterally symmetrical
LIPS
COMPETENT: Slight contact of the lips when the musculature is relaxed. Up to 4mm of lip separation is normal especially in young children.
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INCOMPETENT LIPS
Is defined as the inability to seal the lips without excessive strain.
Anatomically short upper lip which do not contact when the musculature is relaxed. Lip seal is achieved after active contraction of orbicularis oris & mentalis muscle
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Vig & Cohen “Vertical growth of the lips, A serial cephalometric study” A.J.O 75:405 1979
Both upper & lower lip grew more than the skeletal lower face.
The lower lip grew vertically more than the upper lip.
Most children exhibited lip incompetence at age 6-8 yrs. This is due to incomplete soft tissue growth & should be considered normal. www.indiandentalacademy.com
POTENTIALLY INCOMPETENT EVERTED LIPS ď‚Ą
Lip seal is prevented due to protruding max. incisors despite normally developed lips.
These are hypertrophied lips with redundant tissue & weak muscular tonicity
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VERTICAL LIP RELATIONSHIP ď‚Ą
In a balanced face the length of the upper lip measures 1/3rd the lower lip & the chin 2/3rd of the lower face ht.
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ď‚Ą
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The upper incisal edge exposure with the upper lip at rest should be normally 2mm. It is important to distinguish excessive exposure of teeth caused by over eruption of the incisors from that caused by underdevelopment of the upper lip.
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LIP STEP-KORKHAUS ď‚Ą
Positive lip step: Protrusion of the lower lip in relation to the upper lip. Seen in class 3 malocclusion.
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NORMAL LIP PROFILE ď‚Ą
Slightly negative lip profile. The lower lip slightly behind the upper lip.
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NEGATIVE LIP STEP ď‚Ą
Marked retrusion of the lower lip as a symptom of class 2 malocclusion.
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MAMANDRAS “Linear changes of the maxillary & mandibular lips” A.J.O 94:405,1988 Max. lip length in females-14yrs.The mand. vertical lip length growth -16yrs.They attained the max. Lip thickness by age 14 followed by thinning. Males attained max lip length-18yrs,it was not complete. Max lip thickness was attained by 16yrs. Thus the effect of extraction therapy would be more noticeable in females with straight or convex profile than in males. www.indiandentalacademy.com
NASOLABIAL ANGLE-110degree
Formed b/w a tangent to the lower border of the nose & a line joining the subnasale with the tip of the upper lip. (Labrale Superius) Reduces: max. prog., proclined ant. Obtuse: Retrognathic maxilla
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CHIN
The bone structure
Thickness & tone of the mentalis muscle
Morphology & craniofacial relation of the mandible.
Recessive, adequate or prominent. www.indiandentalacademy.com
MENTALIS ACTIVITY
The mentalis muscle becomes hyperactive.
Seen in class 2 div 1 cases where puckering of the chin may be seen.
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MENTOLABIAL SULCUS ď‚Ą
It is the concavity present below the lower lip.
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DEEP SULCUS
SHALLOW SULCUS
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OVER DEVELOPMENT OF THE CHIN HT. (Mentolabial sulcus to menton)
Lip closure is difficult in this type of facial morphology. Hyperactivity of the mentalis muscle Genioplasty required to change the insertion of the mentalis muscle.
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CHIN FORMATION & PROFILE CONTOUR
Protruded chin, marked mentolabial sulcus – retruded lip profile. Negative chin, absence of the mentolabial sulcus causing a protruded lip profile.
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ASYMMETRY OF THE CHIN:MIDLINE OF THE MANDIBLE
Rotation of the entire mandible to the left side- MANDIBULAR LATEROGNATHY Placement of the chin on to the left side.
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TONGUE
Small, Long & broad. Long tongue: Tip of the nose.
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TONGUE WIDTH ď‚Ą ď‚Ą
Class3:Broad ,low lying Imprints of the teeth on the lateral margins of the tongue indicate a discrepancy b/w the width of the dental arch & width of the tongue. Size of the oral cavity should not be decreased further by ortho treat.
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LINGUAL FRENUM
Tongue tie-can lead to impaired tongue movements. The tongue lies low.
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LIP & CHEEK FRENA
Maxillary labial frenum Heavy: midline diastema
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FRENECTOMY Only indicated when the attachment is inserted deeply with the fibre inserted into the interdental papilla. Done after the eruption incisors. X ray shows a bony fissure b/w the roots of upper CI. BLANCH TEST: Upper lip is held away - pull is exerted on the frenum-Area around the incisive papilla becomes blanched.
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MANDIBULAR LABIAL FRENUM ď‚Ą
Broad insertion which exerts a strong pull on the FREE & ATTACHED GINGIVA can lead to gingival recession.
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GINGIVA
Gingival type: Thick fibrous or thin fragile.
Gingival inflammation
Mucogingival regions
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THIN FRAGILE GINGIVA
Alv. Process is narrow Roots can be palpated through the mucosa. Gingival recessions develop around the lower incisors. Visible vascular pattern of mucous membrane Increased tendency of the tissue to produce periodontal damage by labiolingual orthodontic movement
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IDIOPATHIC GINGIVAL HYPERPLSIA ď‚Ą
Hereditary, hinders dental eruption
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OCCLUSAL TRAUMA LINGUAL RECESSIONS
Lead to mucogingival problems
Anomalous relation b/w the tip of the tongue & the lower incisors. Tongue dyskinesia
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PALATE
Palatal depth & shape varies in accordance with the facial form. Brachycephalic pt.- have broad & shallow palate. Rugae can be used as a diagnostic criteria for ant. proclination. Third rugae can be seen in line with the canine. www.indiandentalacademy.com
PALATAL MUCOSA & PALATAL VAULT
Palatal swellingDisplaced tooth germs & cysts.
Ulceration
Scar tissue formation
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MUCOSAL INDENTATIONS
Traumatic deep bite class2 div 1 Groove in the palatal mucosa caused by the lower anterior teeth due to long standing vertical occlusion.
SCAR TISSUE
Scarred palate after surgical closure of an isolated palatal cleft.
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DENTAL CHARACTERISTICS
No. of teeth present, unerupted, missing
The counting must include not only the teeth seen but those developing or not developing within the jaws.
Girls develop teeth earlier than boys.
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APICAL BASE ď‚Ą
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Balanced relationship b/w the width of the dental arches & transverse development of the apical bases. Tangents along the outer surfaces of posterior teeth are parallel to each other.
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DISHARMONY IN WIDTH OF APICAL BASE & MAX. DENTAL ARCH (APICAL CROWDING)
Upper post. teeth are tilted buccally in comparison to their apical base. Cranially convergent tangents of the posterior buccal tooth surface imply that the basal bone is smaller than the dental arch. Expansion of the dental arch is contraindicated.
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BROAD APICAL BASE
The apical base is wider than the dental arch & the posterior teeth are tipped lingually. Discrepancy is indicated by interdental spacing. The tangents of the post. buccal surfaces converge occlusally. Expansion therapy is indicated.
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CARIOUS TEETH ď‚Ą
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Orthodontic treatment is contraindicated when carious teeth are present. There is reduced enamel resistance which is a contraindication for fixed appliance treatment.
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WEAR FACETS ď‚Ą
Occlusal abrasions are a result of attrition & indicative of parafunctional mandibular movements.
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TOOTH FORM & SIZE
Crown size discrepancy: cannot attain proper alignment & intercuspation. Discrepancy b/w tooth size & arch dimension : crowding
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INTERARCH DISCREPANCIES
NEUTRO-OCCLUSION The anteroposterior relationship of the maxillary and mandibular molars is correct, with the mesiobuccal cusp of the maxillary 1st molar occluding in the mesiobuccal groove of the mandibular 1st molar.
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CLASS - 2
DISTO OCCLUSION The lower dental arch is in a distal relationship to the upper dental arch. The mesiobuccal groove of the mandibular 1st molar contacts the distobuccal cusp of the maxillary 1st molar
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CLASS - 3 ď‚Ą ď‚Ą
MESIO-OCCLUSION The mandibular 1st molar is mesial to the maxillary 1st molar and the mandibular incisors are in anterior crossbite.
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OVERBITE ď‚Ą
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The vertical overlap 0f the maxillary incisors over the mandibular incisors is termed as OVERBITE. The maxillary and the mandibular incisors should be in contact in order to prevent supra eruption of the mandibular incisors
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VARIATIONS IN THE BITE - DEEP BITE
INVERTED OVERBITE
CROWN LENGTH
CLOSED BITE: Due to premature loss of posteriors.
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OVERJET- MEAN VALUE-2mm
Is the term used to express the horizontal distance between the most labial surface of the mand. Incisor and the incisal edge of the max. incisor. Equal to the labio lingual thickness of the max. incisor edge. Reflects the anteroposterior relationship Sensitive to abnormal lip and tongue function. Variations are due to abnormal position of either upper or lower incisors.
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CURVE OF SPEE ď‚Ą
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It refers to the anteroposterior curvature of the occlusal surface beginning at the tip of the lower cuspid & following cusp tip of bicuspids & molars continuing as an arc through the condyle. Results in the alignment of teeth to offer max. resistance to functional loading.
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Excessive: restricts the amt. space available for the upper teeth. Normal: Flat Reverse: creates excessive space in the upper jaw.
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CROSS BITE
An abnormal relationship of one or more teeth to one or more teeth of the opposite arch ,in the buccolingual or labiolingual direction. Can be dental or skeletal. Can be either unilateral or bilateral.
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TRANSVERSE OCCLUSAL DEVIATIONS OF THE POSTERIOR SEGMENT
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INTRA ARCH DISCREPANCY
Occlusal view of the orthodontic casts: crowding, spacing & rotation. “Arch width and form” A.J.O 1999:115:305-313 Robert et al: Male arches grow wider than female. Lower intercanine width does not increase after 12yrs. Little changes occur in the premolar arch width after the age of 12. The upper & lower intermolar width increases to a considerable extent b/w ages 7 & 18. www.indiandentalacademy.com
Expansion can be applicable to a growing child. There is no evidence that appliance can stimulate growth beyond that which would occur normally. Arch expansion is more stable in the absence of extractions & is most effective in the posterior region. There is unlikely to be stable expansion in the lower intercanine width unless the canines are displaced lingually. Expansions of the arches posteriorly can be achieved more readily where anteroposterior movement of the arches take place. www.indiandentalacademy.com
VISUAL TREATMENT OBJECTIVE
Can give an excellent clue whether any functional appliance that postures the mandible forward would improve the facial appearance & the profile. The patient is asked to to posture the mandible forward into a correct sagittal relationship. Profile improves-motivates the pt. to achieve a treatment goal. Not improved-other forms of treatment are required. www.indiandentalacademy.com
Indicated in: Functinal retrusion, deep overbites excessive interocclusal clearances with a normally positioned maxilla. V.T.O: manually or cephalometric tracing Tracing represents the changes expected or desired during treatment. In a child the V.T.O would have to incorporate the expected growth, any growth changes induced during treatment & any repositioning of teeth expected from orthodontic tooth movement. www.indiandentalacademy.com
STUDY MODELS ď‚Ą
Replica of the patients oral condition.
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Serves as an important reference as the case progresses.
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ADVANTAGES
Records dental anatomy. Records intercuspation. Arch form Measures progressAids in pt. motivation Space analysis Permanent record medico legal considerations Inexpensive
DISADVANTAGES
Occupy large amt. of space. Liable to damage during storage & transportation. Difficult to discuss a particular case over the phone.
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HOLOGRAMS
Holography uses laser light to reproduce a very high quality, three dimensional image of the cast. The recorded image is called a HOLOGRAM. The first hologram was produced by LEITH & UPATNIEKS in 1964. They permit three dimensional model analysis, superimpositions & storage. HOLOGRAPHIC VIEWS: Frontal, occlusal,Rt. buccal & left buccal.
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Holograms in orthodontics: A.J.O Oct 1995
SYSTEM: Holocamera, the automatic developer, illumination & measureing system. Holocamera: easy to handle. The model being photographed is placed on glass plate for exposure. The laser beam used in the camera is divergent.
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AUTOMATIC DEVELOPER
Developed to expose plates without assistance. Consists of series of trays that contain the various chemicals used, a mechanical engine that controls the movements of the holder in which plates can be placed. 30 plates can be developed simultaneously. The holder carries the plate from tray to tray each having a different function during exposure.
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MEASUREMENT SYSTEM ď‚Ą
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Illumination element: Halogen lamp: to illuminate the hologram. Analysis or measuring element: Plate holder mounted on an x-y-z positioner. The z micropositioner has an optical fiber which is connected to a laser diode that projects a small red spot light used for depth measurement.
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ORTHODONTIC APPLICATIONS
Measurement of incisor intrusion. Study the effects of high pull headgear. Tooth position measurements. Study the effect of max. expansion on facial skeleton. Study the effect of class2 elastics on bone displacement. Study the effect of cervical headgear on maxilla. Facial & dental arch symmetry. Determine the centre of rotation produced by orthodontic forces. Lower incisor space analysis. www.indiandentalacademy.com
ADVANTAGES
Convenient, low bulk Resistant to almost all destructive agents apart from fire. These films may be scratched or bent or covered in dust without interfering with the latent image. Superimposition of images is possible, thus detection of any changes & tooth movement are possible. Holographic image can be measured in 3 dimensions. Ease in storage, transportation Cost similar to conventional photography.
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DISADVANTAGES
Inability to place the holograms immediately next to the patient’s mouth to make side by side comparisons. Cannot be adjusted once made. Incorrect occlusion of the models when the holograms are being made. www.indiandentalacademy.com
OCCLUSOGRAMS
Involves positive-print 1:1 photographs of dental casts. The tracings of these photographs are called as occlusograms. These are actual size photographs of the occlusal surface of the dental cast. Developed by C.J BURSTONE in 1961. Thus combining occlusograms & cephalometric head films it now possible to make treatment discussions in all three planes of space. TECHNIQUES: Photographic & photocopying www.indiandentalacademy.com
OCCLUSOGRAM SET-UP
4 into 5 inch box camera mounted on a sliding rack so that the distance from the track is adjusted. registration track on the oclusostat for the placement of the cast. The occlusal surfaces of the teeth are flush with the leading edge of the oclusostat which is also the focal length of the camera.
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The recommended focal length of the camera:210mm & can be stopped down to f:45 for the best depth of field. The dist. from the leading edge of the occlusostat to the camera lens & from the camera lens to the film is abt.42cm.At these settings no enlargement is found. Exposure time:5-30 secs. depending on the lighting (incandescent to florescent) & the film can be processed with X-ray developer & fixer. www.indiandentalacademy.com
OCCLUSOGRAM PROCEDURE
The occlusal surfaces of the upper & lower dental casts are photographed in a 1:1 ratio & a tracing is made using the photographs. 4 into 5 inch positive film transparencies are ideal. These transparencies allow the occlusograms to be held one over the other to examine cuspal relations. However for treatment planning purpose tracings are still required. These photographs can be taken either with a 35mm camera & enlarged to a 1: 1 magnification or with a 4 into 5 inch Polaroid camera for 1:1 instant photographic prints. Photographic prints are ideal for tracing purposes. One problem with these positive film traspararencies is the maintenance of the accurate orientation of the dental cast, which needs to be trimmed in the centric relation position www.indiandentalacademy.com
Impressions are made-casts are poured & trimmed. The posterior borders are trimmed perpendicular to the occlusal plane & the palatal midline. They are in flush with each other when the casts are in C.R. The bases are parallel to the occlusal plane. Wax jaw registration is made with the mandible in most retruded position, recording the occlusal surfaces without perforating the wax. For lateral orientation each cast has an extended registration groove. The casts are then finished & polished. www.indiandentalacademy.com
OCCLUSOGRAM TRACING
For the occlusogram tracing acetate paper with the rough side up is placed over the occlusograms & the max. & mand. teeth are outlined ,showing the gingival tooth contour, incisal edges, buccal cusp ridges, central grooves & cusp tips, the upper & lower registration lines, mid sagittal reference line based on the mid palatal raphe & incisive papilla. “R” & “L” should be marked on the right & left sides to avoid confusion.
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TECHNIQUE USING PHOTOCOPYING
The study models are prepared as described earlier. With models in the centric relation & teeth in occlusion three marks on each model are made. i.e. on the rt. & lt. side of the buccal segment & in the midline. The casts are then photocopied on a Xerox machine & the occlusal photocopy is used to obtain a tracing.
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ORTHODONTIC APPLICATIONS
Determine arch form & width. Arch length discrepancies (crowding or spacing). To estimate occlusal relationships. To estimate tooth movements in all three planes. Anchorage requirements in each quadrant for extraction cases. The presence & extent of skeletal asymmetries. Presence & extent of tooth mass discrepancies. Determines changes in the cant of occlusal plane. Aid in arch wire construction. Growth changes in the arch can be seen with the help of the tracings. Quantifying treatment progress. www.indiandentalacademy.com
DISADVANTAGES
Not very accurate. Time consuming Possibility of using a occlusogram with a head film produces difference in magnification. To overcome this a user friendly software was developed…………!
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3-D OCCLUSOGRAM SOFTWARE
A.J.O Sept. 1999 The procedure includes : Image scanning & setting. Occlusal view processing Lateral cephalometric processing Occlusogram construction
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ADVANTAGES
Combination of lateral cephalometric image with the occlusal views of the upper & lower dental casts complete the 3 dimensional set up of the patient. Demonstrates all the treatment possibilities. All the needed movements of the teeth are clearly visible on the occlusal views in the 3 planes of space allowing the design for the “custom made appliance” & the lateral cephalogram shows the planned displacement for the molars & the incisors. The software can simulate the results of standard surgical procedures. Ease in using Accurate & precise www.indiandentalacademy.com Rapid
e-MODELS-3D Digital dental models using laser technology- J.C.O (2)-2003
Three dimensional digital study model. Methods of producing digital models: Destructive imaging: Removes the part of the cast ,a little at a time ,while it is being imaged. Non destructive imaging: Uses structural light ,laser light or x-rays to image while leaving the original cast intact.
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e - models: are constructed through a laser scanning process that digitally maps the geometry of a patient’s dental anatomy to a high resolution 3D digital image with an accuracy of .+ 01mm.A laser stripe is projected onto the surface of the plaster cast & a digital camera is used to analyze distortions in the stripe. The plaster cast is oriented on all axes to expose all its surfaces for scanning.
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This process produces 3D vertices that are connected into thousands of triangles to form the 3D image. The software then displays the emodel on the computer screen by assigning color shades to each triangle based on its relative orientation to a digital light source. This results in a high-resolution 3D image that can be viewed measured & manipulated on the computer screen as if the cast is in your hand. www.indiandentalacademy.com
ADVANTAGES OF e-model
Measurements can be made in any plane or orientation. Various analysis such as Bolton’s analysis, arch width & length analysis can be done. Cross-sectional tools allow e-models to be sliced in any vertical or horizontal plane to check symmetry, overjet, overbite & complete measurements at any location. Permits analysis of occlusal relationships. Improves accuracy & efficiency of orthodontic diagnosis, treatment planning & bracket placement. Midline analysis (skeletal or dental asymmetries can be evaluated). Mock surgeries & presurgical evaluation can be done. Record keeping Ease in storage www.indiandentalacademy.com
e-plan Latest innovation in 3D treatment planning. Simulates multiple treatment options to help determine the most effective treatment plan. Enables the clinician to simulate tooth rotations ,movements & extractions with a click of the mouse. They allow pts. to watch the movement of their own teeth from a malocclusion view to a post treatment view. Effective communication tool for pts., their families www.indiandentalacademy.com & referring dentists.
PHOTOCOPYING
Photocopies of models appear to be valid for: Comparing pre & post treatment arch forms. Checking original tooth rotations For ease in communication Producing occlusograms for demonstration purposes. For maintaining pt. record. Adv: Easy to handle & store www.indiandentalacademy.com
DISADVANTAGES Less precise for measuring arch length. Less precise for producing occlusograms for space analysis Can produce varying degree of distortion since the models are 3 dimensional. The distortion can be limited to 1-2% enlargement.
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DIGIGRAPH
Is a synthesis of video imaging, computer technology & three dimensional sonic digitizing. It enables the clinician to perform non invasive & non radiographic cephalometric analysis. Product of DOLPHIN IMAGING SYSTEMS www.indiandentalacademy.com
DIGIGRAPH WORK STATION EQUIPMENT
Measures about 5 feet into 3 feet into 7 feet. The main cabinet contains electronic circuitry & the pt. sits next to the cabinet in an adjustable chair. The head holder is suspended from a boom, supported by a vertical column attached to the cabinet. Two videocameras, permanently armed & focused are mounted on a vertical column. Light emanates from sources inside the boom, thus ensuring all images are properly illuminated.
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This device uses sonic digitizing electronics to record cephalometric landmarks by lightly touching the sonic digitizing probe to the pt. skin. This emits a sound which is then recorded by a microphone as x, y,z coordinates.
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OPTIONAL COMPONENTS INCLUDE
A consultation unit that transports information into the operatory, doctors office or consultation area thus allowing viewing & comparison of information & development of visual treatment objectives. 2nd high resolution video camera with a telephoto lens for taking intra oral views Light box for x-rays & a study model holder for video imaging. Camera & video printer for producing copies of video monitor information. www.indiandentalacademy.com
CAPABILITIES OF THE MACHINE
A landmark can be identified as a point in three dimensions. A cephalometric analysis can be made independent of head position. Neither parallelism of the x-ray in the mid sagittal plane nor the symmetry of anatomic morphology b/w left & rt. side is necessary. www.indiandentalacademy.com
ORTHODONTIC APPLICATIONS
Perform cephalometric analysis e.g. Holdaway, Jaraback, Down, Steiner, Burstone, Tweed, Ricketts Superimpositions Monitor patient treatment progress VTO Useful in quantifying facial asymmetries Allows pts. radiograph, photos& models to be stored on a small disk thereby reducing storage requirements. Valuable tool for improving communication among clinician patient & staff. www.indiandentalacademy.com
ADVANTAGES
Non invasive Consistent & reproducible No radiation exposure With practice relatively efficient.
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3 DIMENSIONAL CONE BEAM COMPUTERIZED TOMOGRAPHY IN ORTHODONTICS
Computerized tomography was developed by GODFREY HOUNSFIELD in 1967.
It utilizes conventional x-ray technology & computerized volumetric reconstruction to reproduce a three dimensional image.
The object to be evaluated is captured as the radiation source falls onto a 2 dimensional detector.
Images may be a full head view, skull view or regional components. www.indiandentalacademy.com
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Produces a more focused beam & less scatter radiation as compared to the conventional fan shaped CT devices. Increases x-ray utilization & reduces the Xray tube capacity.
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CBCT ACQUISITION SYSTEMS
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ORTHODONTIC APPLICATIONS
To locate ectopic cuspids & to design treatment strategies that allow minimally invasive surgery. Location of oral abnormalities (oral cysts, ectopic/ buried teeth & supernumeraries). Airway & volumetric analysis Assessment of bone density, dimensions. quality & alveolar bone height. Implant therapy Imaging TMJ www.indiandentalacademy.com
ADVANTAGES
DISADVANTAGES
Radiation exposure is less than conventional CT. It depends upon the settings used- kVp & mA. Effective dose as low as 45uSv to as high as 650uSv. Less expensive & smaller than conventional CT.
Does not map out muscle structures & their attachments. Does not capture color texture of the skin. Long capture time for the full view of the subject:30-40 secs. during which involuntary muscle movements (nostrils & breathing) will lead to inaccuracies in the soft tissue capture. High maintenance
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BIBLIOGRAPHY
Orthodontic diagnosis: Thomas Rakosi Graber Vanarsdall: Orthodontics current principles & techniques Athanasios: Orthodontic cephalometry Proffit: Contemporary orthodontics Swain: Orthodontics: Current principles & techniques T.M Graber: Orthodontics principles & practice www.indiandentalacademy.com
“IMPROVING SMILE”USING INNOVATIVE TECHNOLOGY
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