NEET MDS Synopsis
Lip Bumper
OrthodonticsLip Bumper
A lip bumper is an orthodontic appliance designed to create
space in the dental arch by preventing the lips from exerting pressure on the
teeth. It is primarily used in growing children and adolescents to manage dental
arch development, particularly in cases of crowding or to facilitate the
eruption of permanent teeth. The appliance is typically used in the lower arch
but can also be adapted for the upper arch.
Indications for Use
Crowding:
To create space in the dental arch for the proper alignment of
teeth, especially when there is insufficient space for the eruption of
permanent teeth.
Anterior Crossbite:
To help correct anterior crossbites by allowing the anterior teeth
to move into a more favorable position.
Eruption Guidance:
To guide the eruption of permanent molars and prevent them from
drifting mesially, which can lead to malocclusion.
Preventing Lip Pressure:
To reduce the pressure exerted by the lips on the anterior teeth,
which can contribute to dental crowding and misalignment.
Space Maintenance:
To maintain space in the dental arch after the premature loss of
primary teeth.
Design and Features
Components:
The lip bumper consists of a wire framework that is typically made
of stainless steel or other durable materials. It includes:
Buccal Tubes: These are attached to the molars
to anchor the appliance in place.
Arch Wire: A flexible wire that runs along the
buccal side of the teeth, providing the necessary space and support.
Lip Pad: A soft pad that rests against the
lips, preventing them from exerting pressure on the teeth.
Customization:
The appliance is custom-fitted to the patient’s dental arch to
ensure comfort and effectiveness. Adjustments can be made to accommodate
changes in the dental arch as treatment progresses.
Mechanism of Action
Space Creation:
The lip bumper creates space in the dental arch by pushing the
anterior teeth backward and allowing the posterior teeth to erupt
properly. The lip pad prevents the lips from applying pressure on the
anterior teeth, which can help maintain the space created.
Guiding Eruption:
By maintaining the position of the molars and preventing mesial
drift, the lip bumper helps guide the eruption of the permanent molars
into their proper positions.
Facilitating Growth:
The appliance can also promote the growth of the dental arch,
allowing for better alignment of the teeth as they erupt.
Nephrosclerosis
General Pathology
Nephrosclerosis
Disease of the renal arteries.
Clinical manifestations:
(1) Benign (arterial) nephrosclerosis → Caused by the formation of atherosclerotic plaques in the renal artery. Results in narrowing of the arterioles.
(2) Malignant nephrosclerosis → Caused by malignant hypertension. Common signs of malignant hypertension include severe hypertension, retinal hemorrhages, and hypertrophy of the left ventricle. Results in inflammatory changes in the vascular walls, which may lead to rupture of the glomerular capillaries.
Erythromycin
Pharmacology
Erythromycin
used for people who have an allergy to penicillins. For respiratory tract infections, it has better coverage of atypical organisms, including mycoplasma. It is also used to treat outbreaks of chlamydia, syphilis, and gonorrhea.
Erythromycin is produced from a strain of the actinomyces Saccaropolyspora erythraea, formerly known as Streptomyces erythraeus.
Mechanism of action Erythromycin prevents bacteria from growing, by interfering with their protein synthesis. Erythromycin binds to the subunit 50S of the bacterial ribosome, and thus inhibits the translocation of peptides.
Erythromycin is easily inactivated by gastric acids, therefore all orally administered formulations are given as either enteric coated or as more stable salts or esters. Erythromycin is very rapidly absorbed, and diffused into most tissues and phagocytes. Due to the high concentration in phagocytes, erythromycin is actively transported to the site of infection, where during active phagocytosis, large concentrations of erythromycin are released.
Most of erythromycin is metabolised by demethylation in the liver. Its main route elimination route is in the bile, and a small portion in the urine.
Erythromycin's half-life is 1.5 hours.
Side-effects. More serious side-effects, such as reversible deafness are rare. Cholestatic jaundice, Stevens-Johnson syndrome and toxic epidermal necrosis are some other rare side effects that may occur.
Contraindications Earlier case reports on sudden death prompted a study on a large cohort that confirmed a link between erythromycin, ventricular tachycardia and sudden cardiac death in patients also taking drugs that prolong the metabolism of erythromycin (like verapamil or diltiazem)
erythromycin should not be administered in patients using these drugs, or drugs that also prolong the QT time.
Intramembranous ossification
Anatomy
Intramembranous ossification
Flat bones develop in this way (bones of the skull)
This type of bone development takes place in mesenchymal tissue
Mesenchymal cells condense to form a primary ossification centre (blastema)
Some of the condensed mesenchymal cells change to osteoprogenitor cells
Osteoprogenitor cells change into osteoblasts which start to deposit bone
As the osteoblasts deposit bone some of them become trapped in lacunae in the bone and then change into osteocytes
Osteoblasts lie on the surface of the newly formed bone
As more and more bone is deposited more and more osteocytes are formed from mesenchymal cells
The bone that is formed is called a spicule
This process takes place in many places simultaneously
The spicules fuse to form trabeculae
Blood vessels grow into the spaces between the trabeculae
Mesenchymal cells in the spaces give rise to hemopoetic tissue
This type of bone development forms the first phase in endochondral development
It is also responsible for the growth of short bones and the thickening of long bones
Parvoviruses
General Pathology
Parvoviruses
- smallest DNA virus
- erythema infectiosum (fifth disease) is characterized by a confluent rash usually beginning on the cheeks ("slapped face") which extends centripetally to involve the trunk; fever, malaise and respiratory problems; and arthralgias and joint swelling (50%).
other associations:
- aplastic anemia in patients with chronic hemolytic anemias (e.g., sickle cell disease, spherocytosis).
- repeated abortions associated with hydrops fetalis.
- pure RBC aplasia by involving the RBC precursors (no reticulocytes peripherally).
-chronic arthritis
Behavioral Classification
PedodonticsBehavioral Classification Systems in Pediatric Dentistry
Understanding children's behavior in the dental environment is crucial for
effective treatment and management. Various classification systems have been
developed to categorize these behaviors, which can assist dentists in guiding
their approach, systematically recording behaviors, and evaluating research
validity.
Importance of Behavioral Classification
Behavior Guidance: Knowledge of behavioral
classification systems helps dentists tailor their behavior guidance
strategies to individual children.
Systematic Recording: These systems provide a
structured way to document children's behaviors during dental visits,
facilitating better communication and understanding among dental
professionals.
Research Evaluation: Behavioral classifications can aid
in assessing the validity of current research and practices in pediatric
dentistry.
Wright’s Clinical Classification
Wright’s clinical classification categorizes children into three main groups
based on their cooperative abilities:
Cooperative:
Children in this category exhibit positive behavior and are
generally relaxed during dental visits. They may show enthusiasm and can
be treated using straightforward behavior-shaping approaches. These
children typically follow established guidelines and perform well within
the framework provided.
Lacking in Cooperative Ability:
This group includes children who demonstrate significant
difficulties in cooperating during dental procedures. They may require
additional support and alternative strategies to facilitate treatment.
Potentially Cooperative:
Children in this category may show some willingness to cooperate but
may also exhibit signs of apprehension or reluctance. They may need
encouragement and reassurance to engage positively in the dental
environment.
Frankl Behavioral Rating Scale
The Frankl behavioral rating scale is a widely used tool that divides
observed behavior into four categories, ranging from definitely positive to
definitely negative. The scale is as follows:
Rating 1: Definitely Negative:
Characteristics: Refusal of treatment, forceful crying, fearfulness,
or any other overt evidence of extreme negativity.
Rating 2: Negative:
Characteristics: Reluctance to accept treatment, uncooperativeness,
and some evidence of a negative attitude (e.g., sullen or withdrawn
behavior).
Rating 3: Positive:
Characteristics: Acceptance of treatment with cautious behavior at
times; willingness to comply with the dentist, albeit with some
reservations. The patient generally follows the dentist’s directions
cooperatively.
Rating 4: Definitely Positive:
Characteristics: Good rapport with the dentist, interest in dental
procedures, and expressions of enjoyment (e.g., laughter).
Application of the Frankl Scale
Research Tool: The Frankl method is popular in research
settings for assessing children's behavior in dental contexts.
Shorthand Recording: Dentists can use shorthand
notations (e.g., “+” for positive behavior, “-” for negative behavior) to
quickly document children's responses during visits.
Limitations: While the scale is useful, it may not
provide sufficient clinical information regarding uncooperative children.
For example, simply recording “-” does not convey the nuances of a child's
behavior. A more descriptive notation, such as “- tearful,” offers better
insight into the clinical problem.
Dental Formula, Dental Notation, Universal Numbering System
Dental Anatomy
Dental Formula, Dental Notation, Universal Numbering System
A. Dental Formula. The dental formula expresses the type and number of teeth per side
The Universal Numbering System. The rules are as follows:
1. Permanent teeth are designated by number, beginning with the last tooth on the upper right side, going on to the last tooth on the left side, then lower left to lower right
2. Deciduous teeth are designated by letter, beginning with the last tooth on the upper right side and proceeding in clockwise fashion
The Parotid Glands
AnatomyThe Parotid Glands
The parotid glands are the largest of the three pairs of salivary glands.
Each gland is wedged between the mandible and the sternocleidomastoid muscle and partly covers them.
The parotid gland is wrapped with a fibrous capsule (parotid fascia) that is continuous with the deep investing fascia of the neck.
Viewed superficially, the parotid gland is somewhat triangular in shape.
Its apex is posterior to the angle of the mandible and its base is along the zygomatic arch.
The parotid gland overlaps the posterior part of the masseter muscle.
The parotid duct (Stensen's duct) is about 5 cm long and 5 mm in diameter.
It passes horizontally from the anterior edge of the gland.
At the anterior border of the masseter muscle, the parotid duct turns medially and pierces the buccinator muscle.
It enters the oral cavity opposite the second maxillary molar.
Blood Vessels of the Parotid Gland
This gland is supplied by branches of the external carotid artery.
The veins from the parotid gland drains into the retromandibular vein, which enters the internal jugular vein.
Lymphatic Drainage of the Parotid Gland
The lymph vessels of this gland end in the superficial and deep cervical lymph nodes.
Nerves of the Parotid Gland
These nerves are derived from the auriculotemporal nerve and from the sympathetic and parasympathetic systems.
The parasympathetic fibres are derived from the glossopharyngeal nerve (CN IX) through the otic ganglion.
Stimulation of these fibres produces a thin watery (serous) saliva to flow from the parotid duct.
The sympathetic fibres are derived from the cervical ganglia through the external carotid plexus.
Stimulation of these fibres produces a thick mucous saliva.