Should be initiated prior to ossification of the mid-palatal suture
Time of ossification of mid-palatal suture
16 years – in girls
18 years – in boys
Contraindication of RME
Single tooth crossbites
In adults with severe anteroposterior skeletal discrepancies
Vertical growers
Periodontally weak condition
Schedule of activation of expansion screw
For patients upto 15 years – 90° rotation in morning and evening
For patients over 15 years – 45° rotation 4 times a day
Quad helix
Uses:
Expand a narrow arch
Rotation of molars
Brings
Orthopaedic movement in children
Orthodontic movement in adults
Expansion Long Essays
Question 1. Explain slow and rapid expansion, their indications, contraindications, and appliances used. Answer.
Effects Of Rapid Maxillary Expansion:
Open mid-palatal suture:
By compresses PDL
Bends buccal alveolar process and slowly opens the suture
Triangular opening:
Maximum opening at incisor region
Reduces over posterior part of palate
Maximum opening towards oral cavity
Less opening towards nasal aspect
Midline diastema
Buccal tipping of maxillary posteriors
Downward and backward mandibular rotation
Increase in mandibular plane angle
Displacement adjacent cranial bones
Increase in intra-nasal space
Reduction in airway resistance
Expansion Short Essays
Question 1. Expansion screws. Answer.
A typical expansion screw consists of an oblong body with two halves, each half consisting of threaded inner side that receives one end of a double-ended screw
The screw has a central basing with four holes, which receive a key used to turn the screw
The turning of screw to 90 degrees brings about linear movement of 0.18mm
Various types of expansion used in removable and fixed appliances are
Jackscrew
Coffin springs
Qual helix
Isacson
Hyrax
Derischweiler
Activation schedules
According to Timms:
In patient upto 15 years of age – 90 degrees rotation in the morning and evening
In patient over 15 years old – 45 degrees activation 4 times a day
According to Zimring and Isacson:
In growing individuals
Two turns each day for 4-5 days and later one turn per day till the desired expansion is achieved
In non-growing adults
Two turns each day for first 2 days and later one turn per day for next 5-7 days and one turn every alternate day till the desired expansion is achieved
Disturbance in tooth size: Micrognathia, macrognathia
Disturbance in tooth number:
Hypodontia
Anodontia
Oligodontia etc.
Disturbance in alignment of teeth:
Abnormal overjet and overbite
Open bite
Effecting other structures:
Cleft lip and palate
High arched palate
Bimaxillary protrusion
Bimaxillary atresia
Syndromes associated with it:
Down’s syndrome
Gardner’s syndrome
Marfan’s syndrome
Cleido-cranial dysplasia
Mandibulo facial dysostosis
General conditions:
Cherubism
Osteogenesis imperfecta
Retarded tooth eruption
Question 2. Importance of Genetics in Orthodontics. Answer.
First recognized by Frederick G. Kussel in 1836
He found that some of the malocclusions are transmitted from one generation to other
The cause of relapse also has a hereditary influence
Occlusal malrelations, jaw positioning and pressure habits are all results of genetic alteration
Some of examples of genetic malocclusions are
Disturbance in tooth size: Micrognathia, macrognathia
Disturbance in tooth number:
Hypodontia
Anodontia
Oligodontia etc.
Disturbance in alignment of teeth:
Abnormal overjet and overbite
Open bite
Effecting other structures:
Cleft lip and palate
High arched palate
Bimaxillary protrusion
Bimaxillary atresia
Syndromes associated with it:
Down’s syndrome
Gardner’s syndrome
Marfan’s syndrome
Cleidocranial dysplasia
Mandibulo facial dysostosis
General conditions:
Cherubism
Osteogenesis imperfecta
Retarded tooth eruption
Question 3. Syndromes and malocclusions. Answer.
Genetics In Orthodontics Short Questions And Answers
Question 1. Genetic Counselling. Answer.
It is communication between the counsellor and the patients having hereditary disease which enables the parents to decide to continue pregnancy/to abort
It is carried out only between counsellor and parents’ confidential
Decisions must be on the patient, the counsellor must not force the patient
Orthodontics includes the study of the growth and development of the jaws and face particularly and the body generally as influencing the position of the teeth, the study of action and reaction of internal and external influences on the arrested and perverted development.
Introduction To Orthodontics Important Notes
Jackson’s Triad:
Functional Efficiency
As malocclusion affects normal functioning of stomatognathic system
Orthodontic treatment restores it
Structural balance
Three tissues constituents oro-facial region i.e., dentoalveolar, skeletal and soft tissues
Orthodontic treatment obtains a balance among them
Esthetic harmony
Malocclusion effects the facial appearance of the individual
This effects the psychology of the person
Thus orthodontic treatment prevents this by improving the facial appearance
Introduction To Orthodontics Short Essays
Question 1. Aims of orthodontics. Answer.
Summarized by Jackson
Also termed as Jackson’s triad
Aims Of Orthodontics:
Functional Efficiency:
As malocclusion affects normal functioning of stomatognathic system
Orthodontic treatment restores it
Structural Balance:
Three tissues constituents oro-facial region i.e., dentoalveolar, skeletal and soft tissues
Orthodontic treatment obtains a balance among them
Esthetic harmony:
Malocclusion effects the facial appearance of the individual
This effects the psychology of the person
Thus orthodontic treatment prevents this by improving the facial appearance
Introduction To Orthodontics Short Questions And Answers
Question 1. Define orthodontics. Answer.
By British Society
Orthodontics includes the study of the growth and development of the jaws and face particularly and the body generally as influencing the position of the teeth, and the study of action and reaction of internal and external influences on the arrested and prevented development.
Question 2. Sequele of Malocclusion. Answer.
Poor facial appearance
Risk of caries
Predisposition to periodontal diseases
Psychological disturbances
Risk of trauma
Abnormalities of function
TMJ problems
Question 3. Jackson’s triad/Aims of orthodontics. Answer.
Functional efficiency
Structural balance
Esthetic harmony
Question 4. Need for orthodontic treatment. Answer.
For esthetic problems
For restoration of functions
For the balance of oro-facial structure
To prevent periodontal problems
Question 5. Angle’s contribution to orthodontics. Answer.
Chief complaints: Help to identify the expectations of the patient
Medical history: epilepsy, diabetes, and blood dyscrasias complicate the treatment
Dental history: to know the attitude of the patient toward treatment
Pre-natal history: for knowing the condition of the mother during pregnancy
Forcep delivery leads to cross-bite
Post-natal history: to know milestones of development
Family history: some occlusions like clefts are hereditary
Clinical Examination:
General:
Height
Weight
Gait
Posture
Body build
Extra-Oral:
Head shape
Facial form
Facial Profile
Facial symmetry
Facial divergence
Anteroposterior relationship
Facial proportions
Lips
Nose
Nasolabial angle
Intra-Oral:
Tongue
Palate
Gingiva
Frenal attachment
Tonsils
Adenoids
Dentition
Orthodontic Diagnosis Posterior Divergence
Functional Examination:
Postural rest position
Path of closure
TMJ
Swallowing
Speech
Respiration
Study models:
Provide a 3D view of the situation
Uses Of Orthodontics:
Studies occlusion from all aspects
Enables accurate measurement
Treatment planning
Assess the severity of malocclusion
Motivate the patient
For mock surgery
For transparency records
Steps in Fabrication:
Impression making – By alginate
Disinfecting it – By Biocide
Casting the impression – By model stone
Basing and trimming the cast
Finishing and Polishing – By fine-grained sandpaper
Radiographs:
Commonly used radiographs are
Cephalometric: For skeletal malocclusion
IOPA – to know the bone condition
Occlusion radiograph – for arch length
Facial Photographs:
To compare pre and post-treatment conditions
Supplemental Diagnostic Aids
Require only in specialized cases
Includes – electromyography
Hand wrist radiograph
Endocrine test
Estimation of BMR (Basal Metabolic Rate)
Diagnostic set up
Occlusograms
MRI, CT scan
Question 2. What are various diagnostic aids in orthodontics? Write in detail about clinical examination and case history records. Answer.
Diagnostic Aids:
Essential Diagnostic aids:
Case history
Clinical examination
Study models
Certain radiographs
Facial photographs
Supplemental diagnostic aids:
Specialized radiographs
Electromyographs
Hand wrist radiographs
Endocrine tests
Estimation of basal metabolic rates
Diagnostic set-up
Occlusograms
Case History involves:
Personal details:
Name – For maintaining a record
Addressing patient
For communication
Age – for treatment planning
Growth period – Myofunctional appliances
After cessation of growth-surgical treatment
Sex – growth spurts differ in both sex
Address – for further correspondence
Chief complaints: Help to identify the expectations of the patient
Medical history: Epilepsy, diabetes, and blood dyscrasias complicate the treatment
Dental history: To know the attitude of the patient toward treatment
Pre-natal history: For knowing the condition of the mother during pregnancy
Forcep delivery leads to cross-bite
Post-natal history: To know milestones of development
Family history: Some occlusions like clefts are hereditary
Clinical Examination:
General:
Height
Provide information on physical growth and maturation of the patient that may influence oro-facial development
Weight
Provide information on the physical growth and maturation of the patient that may influence oro-facial development
Gait
Gait abnormality is associated with neuromuscular problems
Posture
Abnormal posture can predispose to malocclusion
Body build
Types:
Aesthetic
Thin physique
Narrow dental arches
Plethoric
Obese persons
Large, square dental arches
Athletic
Normal built
Normal-size dental arches
Extra-Oral:
Head shape
Types:
Mesocephalic
The average shape of the head
Normal dental arches
Dolichocephalic
Long and narrow head
Narrow dental arches
Brachycephalic
Broad and short head
Broad dental arches
Facial form:
Types:
Mesoprosopic
Average face from
Euryprosopic
Broad and short facial form
Leptoprosopic
Long and narrow facial form
Facial profile:
Examined by viewing the patient from the side
Diagnoses gross deviations in the maxillo-mandibular relationship
Types:
Straight
Convex
Concave
Facial symmetry:
Determines disproportions of the face in transverse and vertical planes
Facial divergence:
It is an anterior or posterior inclination of the lower face relative to the forehead
Types Of Facial Divergence:
Anterior divergence
Posterior divergence
Straight or orthognathic
Anteroposterior relationship
This can be assessed by the following
Seat the patient in an upright position
Ask to occlude gently
Place index and middle finger at soft tissue points A and B respectively
In class 1 hand is at an even level
In class 2 Index finger is anterior to the middle finger
In class 3 Middle finger is ahead of the forefinger
Facial proportions:
The face is divided into three equal thirds by four horizontal planes
At the level of hairline
Supraorbital ridge
The base of the nose
The inferior border of the chin
Lips:
Types:
Competent lips
Incompetent lips
Potentially incompetent lips
Everted lips
Note:
It contributes to the esthetics of the face
Nasolabial angle:
It is the angle formed between the lower border of the nose and the line connecting the intersection of the nose and the upper lip
It is normally 110 degrees
Intra-Oral:
Tongue:
Abnormalities in the tongue disturb muscle balance and equilibrium leading to malocclusion
Palate:
Examined for
Palatal depth
Presence of swelling
Mucosal ulceration
Presence of clefts
Third rugae
Gingiva:
Examined for
Inflammation
Recession
Mucogingival lesions
Frenal attachment:
Abnormal labial frenum leads to midline diastema
Ankyloglossia leads to the narrowing of the maxillary arch
Tonsils:
Abnormal inflamed tonsils cause alteration in tongue and jaw posture
Adenoids:
Dentition:
Assess the following
Number of teeth present
Number of teeth missing
Status of teeth-erupted or unerupted
Presence of caries, restorations, or malformed
Assess occlusion
Assess overjet and overbite
Assess individual tooth irregularities like rotations, intrusion, and extrusions
Assess transverse relationship
Examine the upper and lower arch separately
Question 3. Exumerate essential diagnostic aids. Describe study models in detail. Answer.
Essential Diagnostic Aids:
Case history
Clinical examination
Study models
Certain radiographs
Facial photographs
Study Models:
Uses Of Diagnostic Aids:
Studies occlusion from all aspects
Enables accurate measurement
Treatment planning
Assess the severity of malocclusion
Motivate the patient
For mock surgery
For transparency records
Requirements Of Diagnostic Aids:
Should accurately reproduce oral structures
Should be pleasing to the eye
Should accurately reproduce occlusion
Should have a clean, smooth surface
Should reproduce as much of the alveolar process as possible
Parts Of Diagnostic Aids:
Anatomic portion
Artistic portion
Steps:
Impression making
Disinfecting the impression
Casting the impression – Using orthodontic stone/model stone
Basing and trimming of cast
Trimming
Step 1: Trimming of mandibular base
Step 2: The back of the mandibular model is made perpendicular to the midline
Step 3: Both casts should occlude
Step 4: Backs of both casts are made right-angled to base
Step 5: Buccal cuts are made on mandibular cast
Step 6: Anterior segments made on lower cast
Step 7: Posterior cuts on the lower cast
Step 8: Buccal cuts made on the upper cast
Step 9: Anterior cuts on the upper cast
Step 10: Posterior cuts on the upper cast
Finishing and polishing – Done using fine-grained sandpaper
Orthodontic Diagnosis Short Essays
Question 1. Intra-oral X-rays in Orthodontics Answer.
Types Of Intra-Oral X-rays:
Intra-Oral Periapical Radiograph:
Techniques:
Paralleling technique
Bisecting angle technique
Uses:
View the presence/absence of teeth
Supernumerary teeth
Root formation
Periapical pathology
PDL space
The contour of alveolar bone – to assess the abnormality
Unerupted teeth – for tooth morphology
Disadvantages:
Not convenient for the entire dentition
Gag reflex
Uncomfortable for children
Bitewing:
Uses:
To assess the height and contour of bone
To evaluate periodontal changes
To assess interproximal calculus
Occlusal:
Uses:
For impacted/unerupted teeth
For supernumerary teeth
For foreign bodies
To view the effects of the arch expansion procedure
Question 2. Inter-incisal angle. Answer.
It is the angle formed between the long axis of the upper and lower incisors
Value – 135.4°
Range – 130 – 150.5°
Significance Of Inter-incisal Angle:
Increased in Class 2, Division 2
Decreased – Class 1 bimaxillary protrusion
Class 2 Division 1
Question 3. Occlusal X-ray. Answer.
Advantages Of Occlusal X-ray:
Views a large segment of the dental arch
For viewing palate and floor of mouth
Useful in trismus
Uses Of Occlusal X-ray:
Locate impacted teeth
Locate fracture
Locate supernumerary teeth
Locate foreign bodies
Locate effects of arch expansion procedures
Assess the arch length
Assess any pathology of jaws
Question 4. Overjet and Overbite. Answer.
Overjet: It is the horizontal overlapping of maxillary and mandibular anterior
Value: 1.5 – 2mm
Significance Of Overjet: Increases in open bite cases
Increases in anterior proclination
Overbite: It is the vertical overlapping of maxillary and mandibular anterior
Value: 1.5 – 2mm
Significance Of Overbit: Decrease – Deep bite
Increase: Open bite
Orthodontic Diagnosis Short Questions And Answers
Question 1. Facial Divergence. Answer.
It is defined as an anterior/posterior inclination of the lower face relative to the forehead
Types Of Facial Divergence:
Anterior divergent: A line between the forehead and chin inclines anteriorly
Posterior divergent: A line between forehead and chin inclines posteriorly
Straight/Orthognathic: A line between the forehead and chin is straight or perpendicular to the floor.
Orthodontic Diagnosis Posterior Divergence
Question 2. Uses of Panoramic Radiograph./Orthopentogram Answer.
Assessing dental development
Studying root resorption/root formation
For Ankylosis
Impacted teeth
Path of eruption
Diagnose pathology
Status of eruption
Unerupted teeth
Question 3. Bite Wing Radiographs. Answer.
Records coronal part of upper and lower dentition together
Uses Of Bite Wing Radiographs:
For proximal caries
For interdental bone contour
For secondary caries
Detect overhanging restoration
Detect periodontal changes
Detect interproximal calculus
Question 4. Electromyography. Answer.
Used for recording the electrical activity of muscles
Types Of Electrodes Used:
Surface electrode – Plated superficially
Needle electrode – Placed deeply
Useful In:
In severe Class 2 division 1 malocclusion
Abnormal buccinator activity
Overclosure of jaws
Cerebral palsy
After orthodontic therapy
Question 5. Clinical Evaluation of Facial Profile. Answer.
The patient is viewed from the side
Reference Lines:
A line from forehead to point A
A line from point A to pogonion
Types Of Profiles:
Straight: Two lines straight line Ex. Class 1 cases
Convex: Two lines form an angle with concavity facing tissue Ex. Class 2, Division 1
Concave: Two lines form an angle with convexity facing tissue Ex. Class 3 malocclusion
Question 6. Importance of Family History. Answer.
Some malocclusions are hereditary
These affect the treatment planning
Thus details of it should not be neglected Ex. Class 2 malocclusion, Cleft lip and palate
Question 7. Kesling’s diagnostic setup. Answer.
Proposed by H.D. Kesling
Used for assessing the effect of treatment
Procedure Of Kesling’s Diagnostic:
Question 8. Freeway Space. Answer.
The position of the mandible at which muscles that are useful in opening and closing of jaws are in a state of minimal contraction is called posture rest position
At this position, space is present between both the jaws
This is called free-way space
Value – 3mm
Site – In canine region
Question 9. Gnathostatic Models. Answer.
Type of study model
Uses: Provide 3D view of occlusion
For treatment planning
For assessing the outcome
Gnathostatic:
Question 10. Overjet. Answer.
It is a horizontal overlapping of the maxillary and mandibular anterior
Value: 1.5 – 2mm
Significance Of Overjet: Increases in open bite cases
Increases in anterior proclination
Question 11. Nasolabial angle. Answer.
It is the angle formed between the lower border of the nose and the line connecting the intersection of the nose and the upper lip
It is normally 110 degrees
Reduces in
Patients having proclined upper anterior or prognathic maxilla
Increases in
Patients with retrognathic maxilla or reclined maxillary anterior
Question 12. Cephalic index Answer.
The cephalic index was described by Martin and Saller in 1957
It is calculated as follows
Cephalic index = Maxillary skull width / Maxillary skull length
Interpretation Of Cephalic Index:
Value – 76-80.9
Indicates mesocephalic individuals
Value – 81-85.4
Indicates brachycephalic individuals
Value < 75.9
Indicates dolichocephalic individuals
Value > 85.5
Indicates hyperbradycephalic
Question 13. Orthodontic study models Answer.
Uses Of Orthodontic Study Models:
Studies occlusion from all aspects
Enables accurate measurement
Treatment planning
Assess the severity of malocclusion
Motivate the patient
For mock surgery
For transparency records
Requirements Of Orthodontic Study Models:
Should accurately reproduce oral structures
Should be pleasing to the eye
Should accurately reproduce occlusion
Should have a clean, smooth surface
Should reproduce as much of the alveolar process as possible
Parts Of Orthodontic study models:
Anatomic portion
Artistic portion
Question 14. Importance of medical history Answer.
Some medical conditions contraindicate the use of orthodontic appliances
They may require special precautionary measures to be taken before or during orthodontic therapy
It is advisable to delay orthodontic treatment in patients suffering from epilepsy until it is controlled
Patients with a history of blood dyscrasias may need special management if extractions are planned
Diabetic patients can undergo orthodontic therapy if it is under control
Patients having rheumatic fever or cardiac anomalies require antibiotic coverage for certain dental procedures
Children who are severely handicapped either mentally or physically may require special management
The use of aspirin may impede orthodontic tooth movement
Patients suffering from acute, debilitating conditions should be allowed to recover before initiating orthodontic treatment
Orthodontic Diagnosis Viva Voce
Hyperactive mental activity and abnormal buccinators activity are seen in class 2 division 1
Overclosure of jaws is associated with accentuated temporalis muscle activity
Normally the upper lip covers the anterior labial surface of the upper anterior except for the incisal 2-3mm while the lower lip covers the entire labial surface of the lower anterior and 2–3mm of the incisal edge of the upper anterior
With the complete reform of interstate and international travel, accidents are high and causing most of the disasters worldwide
In the analysis of these incidences where children often become victims, the task of identification is very complicated
The vast number of victims who are burnt, decomposed, and mutilated can be overwhelming
These can be systemically examined and identified by the dentist
Question 2. Sunray appearance Answer.
Sunray appearance
It is a radiographic feature of larger lesions
It may cause cortical expansion with radiating spicules at the expanding perphery
This results in the sunray appearance of the lesions
It is seen in
Osteosarcoma
Hemangioma
Osteoblastoma
Question 3. Moth-eaten appearance Answer.
Moth-eaten appearance
It is seen as radiolucent areas
These areas enlarge
Outline is irregular
It gets separated by islands of normal-appearing bone
This is due to the enlargement of medullary spaces and widening of Volkmann’s canals, secondary to lysis of bone and replacement with granulation tissue
It is seen in
Early stage of osteosarcoma
Squamous cell carcinoma
Osteomyelitis
Leukemia
Malignant lymphoma
Question 4. Fracture of teeth Answer.
Types
Concussion:
There is a widening of periodontal ligament space at the apex
Presence of pulpal necrosis and periapical lesion
Luxation:
Refers to dislocation or loosening of teeth due to loss of periodontal attachment
It can be
Intrusive
Extrusive
Lateral
Features:
Disruption of continuity of lamina dura in the apical region
Widening of periodontal ligament space in the periapical region
Presence of pulpal necrosis or calcification of pulp chamber
Avulsion:
Refers to complete displacement of tooth from its socket
Radiographically it shows an empty socket
Radiographic Changes In Fracture Of Teeth:
The radiolucent line between tooth segments
Displacement of tooth fragments
Disruption of the continuity of the tooth surface
In case of root fracture, there may be a radiolucent line transversing the midportion of the tooth suggestive of fracture
Question 5. Lacerated wounds Answer.
Features:
Margins are irregular, ragged, and uneven and their extremities are pointed or blunt.
Bruising is seen either in the skin or the subcutaneous tissues around the wounds
Deeper tissues are unevenly divided with tags of tissue at the bottom of the wound bridging across the margin.
Hair bulbs are crushed.
Hemorrhage is less because the arteries are crushed and torn across irregularly.
Foreign matter may be found in the wound.
Depth varies according to the thickness of the soft parts and the degree of force applied.
A laceration is usually curved.
The skin on the side of the wound opposite to direction of force is usually torn free or undermined.
Question 6. Contrast radiography Answer.
Contrast radiography
Contrast radiography is a method of studying body organs using X-rays and the administration of a special dye, called contrast medium.
The contrast medium will highlight the specific areas in the body and help them to be seen in greater X-ray on the x-ray image.
Contrast medium can be given in different ways, depending on what organ or tissue needs to be examined.
This test allows us to evaluate these structures that are not clear on conventional x-ray exams.
Types:
Various types of contrast radiography are given for different reasons.
Intravenous pyelography, or IVP,
Allows to examine the urinary system, including kidneys, ureters, and bladder, and identify tumors, cysts, and stones.
Upper GI (gastrointestinal) and small bowel series
Used to examine your esophagus, stomach, and upper small intestine and identify ulcers, obstructions, tumors, or inflammations.
A barium enema, also called a lower GI series
Used to examine your colon and rectum and detect polyps, cancer, inflammation, and diverticula [pouches within the colon].
Angiography
Angiograexaminationows to examination of blood vessels and various organs to detect obstructions, tumors, and other problems in the heart, lungs, kidneys, arms, and legs.
Cardiac catheterization
Used to evaluate the heart and its vessels.
Question 7. Professional negligence Answer.
Professional negligence
Professional negligence is a common law tort and broadly occurs when a professional fails to perform his responsibilities to the required standard.
Professional negligence claims have become more common in recent years.
This is due to a combination of factors including an increasing reliance upon professional advice, the complexity of work carried out, and a raised awareness of legal rights.
Professional negligence is a subset of the general rules on negligence to cover the situation in which the defendant has represented him or herself as having more than average skills and abilities.
The usual rules rely on establishing that a duty of care is owned by the defendant to the claimant, and that the defendant is in breach of the duty.
The standard test of breach is whether the defendant has matched the abilities of a reasonable person.
This specialized set of rules determines the standards against which to measure the legal quality of the services delivered by those who claim to be among the best in their fields of expertise.
Question 8. Child abuse Answer.
Definition:
It is defined as the non-accidental physical injury, minimal or fatal, inflicted upon children by persons caring for them
It is an overact of commission of a physical, emotional, or sexual
There are no spontaneous smiles and almost no eye contact among abused children
Lack of cleanliness
Presence of short stature concerning age
Malnutrition
Overdressed children
Periorbital ecchymosis, scleral hemorrhage, ptosis, deviated nasal septum, cigarette burn marks and hand slap marks
Fractured anterior teeth
Short Answers
Question 1. Bite marks Answer.
Definition:
It is a mark caused by teeth alone or in combination with other oral parts or consists of teeth marks produced by the antagonist teeth which can be as two opposing arch marks
Classification:
Depending on the blinding agent
Human
Animals
Mechanical
Depending on the material bitten
Skin
Perishable items
Non-perishable items
Depending on the degree of biting
Definite bite marks
Amorous bite marks
Aggressive bite marks
Characteristics:
An elliptical or ovoid pattern containing tooth and arch marks
Presence of 4-5 teeth marks reflecting the shape of their incisal or occlusal surfaces
The presence or absence of each tooth
The peculiar shape of each tooth
Mesiodistal dimensions
Arch form and size
Relationship between the upper and lower jaws
Question 2. Battered baby syndrome Answer.
Battered baby syndrome
It is a disease in which children are physically abused.
The battered child syndrome is a form of child abuse
It is a child who shows clinical or radiographic evidence of lesions that are frequently multiple and involve mainly the head, soft tissues, long bones, and thoracic cage and cannot be unequivocally explained
Question 3. Identification and aging of the dead from teeth Answer.
Identification and aging of the dead from teeth
Some of the common identifying features of teeth are examined
They are:
Faulty development
Faulty alignment
Localized wear on certain teeth
Missing teeth
Aging is determined by
Root calcification
Stages of eruption
Question 4. Scope of Forensic Dentistry Answer.
Scope of Forensic Dentistry
Forensic dentistry is one of the most rapidly developing branches of forensic medicine
It plays an important role in helping forensic experts identify the affected victims or criminals
It contributes to supporting families to enable them to care for children more adequately and the society to develop sensitivity and skills for respectful and healthy personal relationship
Question 5. Determination of age in forensic dentistry Answer.
Age is determined by
Visual observation
Stages of eruption of dentition are looked for
Attrition of teeth with increasing age is used
Radiography
Provide gross information on dental development of dentition
Histological
Determines the stage of development of the dentition
Physical and chemical analysis
Determine alterations in levels with age
Question 6. Sex determination Answer.
Sex determination
Identification of sex can be determined by
Examining the sexual organs of the victims or their secondary sexual characteristics
Examine sex chromosome
Identification of Bar body in buccal smear
Question 7. Lip prints Answer.
. Lip prints
Lip prints are used as an identification aid
Minor differences have been observed between the right and left sides and between upper and lower lips
Lip prints on drinking glasses, facial tissues, and magazines have been used as evidence in actual court cases also
The science of examining lip prints is called coloscopy
Types Of Lip Prints:
Vertical
Branched
Intersected
Reticular pattern
Question 8. Coolidge’s tube Answer.
Coolidge’s tube
In 1913, William David Coolidge invented the Coolidge tube, an X-ray tube with an improved cathode for use in X-ray machines that allowed for more intense visualization of deep-seated anatomy and tumors.
The Coolidge tube, which also utilized a tungsten filament, was a major development in the then-nascent medical specialty of radiology, and its basic design is still in use.
He invented the first rotating anode X-ray tube.
The Coolidge tube, also called the hot cathode tube, is the most widely used.
It works with a very good quality vacuum (about 10-4pa, or 10-6 Torr).
In the Coolidge tube, the electrons are produced by the thermionic effect from a tungsten filament heated by an electric current.
The filament is the cathode of the tube.
The high voltage potential is between the cathode and the anode, the electrons are thus accelerated and then hit the anode.
Question 1. Describe the principle, indication, and limitations of panoramic radiographs. Or Describe the principles of panoramic radiography. Enumerate its indications and limitations Answer.
Panoramic Radiographs Principle:
This is based on the curvilinear variant of conventional tomography
The movement of the tube head and the film produces an image through the process known as “tomography”
Curvilinear tomography is also based on the principle of reciprocal movement of an X-ray source and an image receptor around a central point or plane called an image layer
Panoramic Radiographs Indications:
As a substitute for full mouth intraoral periapical radiograph
For evaluation of tooth development for children, the mixed dentition and also the aged
To assist and assess the patient for and during orthodontic treatment
To establish the site and size of lesions
Prior to any surgical procedures
Forthe detection of fractures
For follow-up of treatment, progress of pathology or prostoperative bony healing
Investigation of TMJ dysfunction
To study the antrum
For overall view of the alveolar bone levels
Assessment of underlying bone diseases
Evaluation of developmental anomalies
Evaluation of bone level before inserting implants
Panoramic Radiographs Limitations:
Areas of diagnostic interest outside the focal through may be poorly visualized
Poor diagnostic value in terms of magnification, distortion, loss of details
There is overlapping of teeth in the bicuspid area of the maxilla and mandible
In cases of pronounced inclination, the anterior teeth are poorly defined
The density of spine causes lack of clarity in central portion of the film
Formation of ghost images due to soft tissue shadows and air spaces
Panoramic Radiography Short Essays
Question 1. OPG. Or Note on panoramic imaging Or Panoramic radiography Answer.
OPG Definition:
It is a technique for producing a single tomographic image of the facial structures that induces both the maxillary and mandible dental arches and their supporting structures
OPG Principle:
This is based on curvilinear variant of conventional tomography
The movement of the tube head and the film produces an images through the process known as “tomography”
Curvilinear tomography is also based on the principle of reciprocal movement of an X-ray source and an image receptor around a central point or plane called as image layer
OPG Procedure:
Explain the procedure to the patient
Make the patient to remove all the accessories that may interfere with the image
Position the patient such that he is in the focal through
Instruct the patient to look straight
Patient is positioned such that dental arches are located in the middle of the focal through
Occlusal plane is adjusted such that the Frankfort plane is parallel to the floor
This is done by placing central incisor into a notched incisal device with lead marker
Center the lower border of mandible on the chin rest and is equidistant
Instruct the patient to position the tongue on the palate
Exposure the film
Process it as usual
Question 2. Advantages and disadvantages of orthopantomograph Answer.
Orthopantograph:
It is a technique for producing a single tomographic image of the facial structures that induces both the maxillary and mandible dental arches and their supporting structures
Can be used in patients with trismus or in patients who cannot tolerate intraoral radiography
Quick and convenient technique
Useful visual aid in patient education and case presentation
Orthopantograph Disadvantages:
Resolution is very low
Cannot be used in the diagnosis of caries
Cannot be used in the evaluation of bone loss due to periodontal diseases
Shows superimposition, especially in the premolar region
Structures outside the image layer cannot be visualized
Cannot be used as substitute to intraoral radiography
Magnification across image is unequal
Requires accurate patient positioning to avoid positioning errors and artifacts
Difficult to image both jaws when patient have severe maxillomandibular discrepancy
Panoramic Radiography Short Answers
Question 1. Principle of panoramic imaging. Answer.
Panoramic Imaging Principle:
This is based on curvilinear variant of conventional tomography
The movement of the tube head and the film produces an images through the process known as “tomography”
Curvilinear tomography is also based on the principle of reciprocal movement of an X-ray source and an image receptor around a central point or plane called as image layer
Question 2. Advantages of OPG Answer.
Advantages of OPG
Broad coverage of facial bones and teeth
Low radiation dose
Ease of apnoramic radiographic technique
Can be used in patients with trismus or in patients who cannot tolerate intraoral radiography
Quick and convenient technique
Useful visual aid in patient education and case presentation
Question 3. OPG – indications Answer.
OPG – indications
As a substitute for full mouth intraoral periapical radiograph
For evaluation of tooth development for children, the mixed dentition and also the aged
For assist and assess the patient for and during orthodontic treatment
To establish the site and size of lesions
Prior to any surgical procedures
For detection of fractures
For follow up of treatment, progress of pathology or prostoperative bony healing
Investigation of TMJ dysfunction
To study the antrum
For overall view of the alveolar bone levels
Assessment of underlying bone diseases
Evaluation of developmental anomalies
Evaluation of bone level before inserting implants
Panoramic Radiography Viva Voce
3 centers of rotation are there in OPG
Radiation exposure is less for panoramic radiography compared to CT scan. It is highest for arthography.
In panoramic radiograph smiling or appearance of structures is seen if patients chin is tilted downward.
Frowning appearance is seen if patient’s chin is tilted upwards
Question 1. What are the indications for occlusal radiographs? Describe radiographic technique in taking maxillary and mandibular cross sectional occlusal radiograph. Or What are the indications for occlusal radiographs? Describe radiographic technique in taking maxillary and mandibular topographic occlusal radiograph. Answer.
occlusal radiograph Indications:
To locate retained roots of extracted teeth
To locate supernumerary, unerupted or impacted teeth
To locate foreign bodies in the jaw
To locate salivary stones in ducts of submandibular gland
To locate and evaluate the extend of the lesion
To evaluate boundaries of the maxillary sinus
To evaluate fractures of the maxilla and mandible
To aid in examination in patient with trismus
To examine area of cleft palate
To measure changes in the size and shape of the maxilla and mandible
For determining the bucco/palatal position of unerupted canines
Maxillary Cross Sectional View:
Image Field:
It shows palate
Zygomatic process of the maxilla
Anterior inferior aspects of each antrum
Nasolacrimal canals
Teeth from right second molar to left second molar
Nasal septum
Film Placement:
The film is placed crosswise into the mouth and gently pushed back until it contacts the anterior border of the rami
Projection of the Central Ray:
Angulation:
Vertical: +6°
Horizontal: 0°
Entry of central ray through the bridge of the nose
Mandibular Cross Sectional View:
Image Field:
It shows
Soft tissues of the floor of the mouth
Delineates the lingual and Buccal plates of the jaw bone
Teeth from second molar to second molar
Film Placement:
The film is placed in the mouth with its long axis perpendicular to the sagittal plane
The pebbled surface is towards the mandible
The anterior border of the film should be approxiamately 1/2 inch anterior to the Mandibular central incisors
Projection of the Central Ray:
It is directed at right angles to the center of the film
Buccal and lingual objects shift positions when the direction of the X-ray beam is changed. A Buccal and lingual are superimposed in the original radiograph B If the tube head is shifted in the distal direction, the buccal object moves mesially and the lingual object moves distally (same direction = Lingual; Opposite Direction = Buccal)
The right angle technique A – The object appears to be located in bone on the periapical radiograph. B – The occlusal radiograph reveals that the object is located in the soft tissue lingual to the mandible
Right-angled localization technique. Two films are exposed at right angles to each other to identify the location of an object. The periapical radiograph A – will demonstrate the superior-inferior and anterior-posterior position of the objects. A cross-sectional occlusal radiograph B – will demonstrate the anteroposterior and buccal lingual positions. Thus these two radiographs will demonstrate all three dimensions of an area, and the location of objects can be identified
Question 2. Indications and interpretation of Clarke’s technique. Answer.
Clarke’s Technique Indications:
Foreign bodies
Impacted teeth
Unerupted teeth
Retained roots
Salivary stones
Broken needles
Jaw fractures
Filling materials
Root position
Clarke’s Technique Method:
Two radiographs are taken
The first one with proper technique and angulation
The second radiograph is taken by either changing the vertical or horizontal angulation
Clarke’s Technique Interpretation:
When the dental structure or object seen in the second radiograph appears to have moved in the same direction as the shift of the position-indicating device, the structure is said to be positioned lingually
If the object appears to have moved in the opposite direction, then the object is said to be positioned buccally
Clarke’s Technique Slob Rule:
Buccal and lingual objects shift positions when the direction of the X-ray beam is changed. A – Buccal (cross-hatched circle and lingual (black circle) are superimposed in the original radiograph B – if the tube head is shifted in the distal direction, the buccal object moves mesially and the lingual object moves distally (same direction = Lingual; Opposite Direction = Buccal)
Object Localisation Techniques Short Answers
Question 1. SLOB technique. Answer.
SLOB Technique Method:
Two radiographs are taken
The first one with proper technique and angulation
The second radiograph is taken by either changing the vertical or horizontal angulation
SLOB Technique Interpretation:
When the dental structure or object seen in the second radiograph appears to have moved in the same direction as the shift of the position-indicating device, the structure is said to be positioned lingually
If the object appears to have moved in the opposite direction, then the object is said to be positioned buccally
SLOB Technique Slob Rule:
Same side Lingual Opposite side Buccal:
Buccal and lingual objects shift positions when the direction of the X-ray beam is changed. A – Buccal (cross-hatched circle0 and lingual (black circle) are superimposed in the original radiograph B – if the tube head is shifted in the distal direction, the buccal object moves mesially and the lingual object moves distally (same direction = Lingual; Opposite Direction = Buccal)
