NEET MDS Synopsis
Antral Puncture and Intranasal Antrostomy
Oral and Maxillofacial SurgeryAntral Puncture and Intranasal Antrostomy
Antral puncture, also known as intranasal antrostomy, is a
surgical procedure performed to access the maxillary sinus for diagnostic or
therapeutic purposes. This procedure is commonly indicated in cases of chronic
sinusitis, sinus infections, or to facilitate drainage of the maxillary sinus.
Understanding the anatomical considerations and techniques for antral puncture
is essential for successful outcomes.
Anatomical Considerations
Maxillary Sinus Location:
The maxillary sinus is one of the paranasal sinuses located within
the maxilla (upper jaw) and is situated laterally to the nasal cavity.
The floor of the maxillary sinus is approximately 1.25 cm below
the floor of the nasal cavity, making it accessible through the nasal
passages.
Meatuses of the Nasal Cavity:
The nasal cavity contains several meatuses, which are passageways
that allow for drainage of the sinuses:
Middle Meatus: Located between the middle and
inferior nasal conchae, it is the drainage pathway for the frontal,
maxillary, and anterior ethmoid sinuses.
Inferior Meatus: Located below the inferior
nasal concha, it primarily drains the nasolacrimal duct.
Technique for Antral Puncture
Indications:
Antral puncture is indicated for:
Chronic maxillary sinusitis.
Accumulation of pus or fluid in the maxillary sinus.
Diagnostic aspiration for culture and sensitivity testing.
Puncture Site:
In Children: The puncture should be made through
the middle meatus. This approach is preferred due to
the anatomical differences in children, where the maxillary sinus is
relatively smaller and more accessible through this route.
In Adults: The puncture is typically performed
through the inferior meatus. This site allows for
better drainage and is often used for therapeutic interventions.
Procedure:
The patient is positioned comfortably, usually in a sitting or
semi-reclined position.
Local anesthesia is administered to minimize discomfort.
A needle (often a 16-gauge or larger) is inserted through the chosen
meatus into the maxillary sinus.
Aspiration is performed to confirm entry into the sinus, and any
fluid or pus can be drained.
If necessary, saline may be irrigated into the sinus to help clear
debris or infection.
Post-Procedure Care:
Patients may be monitored for any complications, such as bleeding or
infection.
Antibiotics may be prescribed if an infection is present or
suspected.
Follow-up appointments may be necessary to assess healing and sinus
function.
OCCLUSION AND DENTAL DEVELOPMENT-Stages-Deciduous dentition period
Dental Anatomy
Deciduous dentition period.
-The deciduous teeth start to erupt at the age of six months and the deciduous dentition is complete by the age of approximately two and one half years of age.
-The jaws continue to increase in size at all points until about age one year.
-After this, growth of the arches is lengthening of the arches at their posterior (distal) ends. Also, there is slightly more forward growth of the mandible than the maxilla.
1. Many early developmental events take place.
-The tooth buds anticipate the ultimate occlusal pattern.
-Mandibular teeth tend to erupt first. The pattern for the deciduous incisors is usually in this distinctive order:
(1) mandibular central
(2) maxillary central incisors
(3) then all four lateral incisors.
-By one year, the deciduous molars begin to erupt.
-The eruption pattern for the deciduous dentition as a whole is:
(1) central incisor
(2) lateral incisor
(3) deciduous first molar
(4) then the canine
(5) then finally the second molar.
-Eruption times can be variable.
2. Occlusal changes in the deciduous dentition.
-The overjet tends to diminish with age. Wear and mandibular growth are a factor in this process.
-The overbite often diminishes with the teeth being worn to a flat plane occlusion.
-Spacing of the incisors in anticipation of the soon-to-erupt permanent incisors appears late. Permanent anterior teeth (incisors and canines) are wider mesiodistally than deciduous anterior teeth. In contrast, the deciduous molar are wider mesiodistally that the premolars that later replace them.
-Primate spaces occur in about 50% of children. They appear in the deciduous dentition. The spaces appear between the upper lateral incisor and the upper canine. They also appear between the lower canine and the deciduous first molar.
The Soft Palate
Anatomy
This is the posterior curtain-like part, and has no bony support. It does, however, contain a membranous aponeurosis.
The soft palate, or velum palatinum (L. velum, veil), is a movable, fibromuscular fold that is attached to the posterior edge of the hard palate.
It extends posteroinferiorly to a curved free margin from which hangs a conical process, the uvula (L. uva, grape).
The soft palate separates the nasopharynx superiorly and the oropharynx inferiorly.
During swallowing the soft palate moves posteriorly against the wall of the pharynx, preventing the regurgitation of food into the nasal cavity.
Laterally, the soft palate is continuous with the wall of the pharynx and is joined to the tongue and pharynx by the palatoglossal and palatopharyngeal folds.
The soft palate is strengthened by the palatine aponeurosis, formed by the expanded tendon of the tensor veli palatini muscle.
This aponeurosis attaches to the posterior margin of the hard palate.
White Spot Lesions
Pedodontics White Spot Lesions (Incipient Caries)
White spot lesions, also known as incipient caries, are early signs of dental
caries that manifest as opaque areas on the enamel surface. These lesions are
significant indicators of the demineralization process that occurs before the
development of cavitated carious lesions.
Characteristics of White Spot Lesions
Appearance:
White spots are characterized by a high concentration of minerals
and fluoride at the surface layer of the enamel, which diffracts light
and creates an opacity that is clinically visible.
These lesions typically appear as white, chalky areas on the enamel
surface.
Caries Development:
While white spots are recognized as the first clinical evidence of
developing caries, the carious process actually begins much earlier at
the microscopic level.
Demineralization of the enamel occurs before the white spot becomes
visible, indicating that the caries process is ongoing.
Influence of Fluoride:
The presence of fluoride can positively affect the appearance and
texture of white spot lesions:
With Fluoride: The surface of the white spot
becomes smooth and shiny, indicating some degree of remineralization.
Without Fluoride: The lesion appears rough and
chalky, suggesting a higher level of demineralization and a greater
risk of progression to cavitation.
Clinical Considerations
Probing:
It is important to avoid probing the surface of white spot lesions
too aggressively. Although the surface may appear intact, the underlying
enamel is mineral-deficient and weak.
Excessive probing can lead to the breakdown of these weak layers,
potentially resulting in cavitation and the progression of caries.
Management:
Early intervention is crucial for managing white spot lesions.
Strategies may include:
Fluoride Treatments: Application of fluoride
varnishes or gels to promote remineralization.
Dietary Counseling: Educating patients about
reducing sugar intake and improving oral hygiene practices to
prevent further demineralization.
Monitoring: Regular dental check-ups to monitor
the progression of white spot lesions and assess the effectiveness
of preventive measures.
COMPOSITE RESINS - Finishing and Polishing
Dental Materials
Finishing and Polishing
Remove oxygen-inhibited layer .Use stones or carbide burs for gross reduction.Use highly fluted carbide burs or special diamonds for fine reduction.Use aluminum oxide strips or disks for finishing. Use fine aluminum oxide finishing pastes. Microfills develop smoothest finish because of small size of filler particles
INFARCTION
General Pathology
INFARCTION
An infarct is an area of ischemic necrosis caused by occlusion of either the arterial supply or the venous drainage in a particular tissue
Nearly 99% of all infarcts result from thrombotic or embolic events
other mechanisms include: local vasospasm, expansion of an atheroma, extrinsic compression of a vessel (e.g., by tumor); vessel twisting (e.g., in testicular torsion or bowel volvulus; and traumatic vessel rupture
MORPHOLOGY OF INFARCTS
infarcts may be either red (hemorrhagic) or white (anemic) and may be either septic or aseptic
All infarcts tend to be wedge-shaped, with the occluded vessel at the apex and the periphery of the organ forming the base
The margins of both types of infarcts tend to become better defined with time
The dominant histological characteristic of infarction is ischemic coagulative necrosis
most infarcts are ultimately replaced by scar. The brain is an exception, it results in liquefactive necrosis
RED INFARCTS:
occur in
(1) venous occlusions (such as in ovarian torsion)
(2) loose tissues (like lung) that allow blood to collect in the infarcted zone
(3) tissues with dual circulations (lung and small intestine)
(4) previously congested tissues because of sluggish venous outflow
(5) when flow is re-established to a site of previous arterial occlusion and necrosis
WHITE INFARCTS
occur with:
1) arterial occlusions
2) solid organs (such as heart, spleen, and kidney).
Septic infarctions - occur when bacterial vegetations from a heart valve embolize or when microbes seed an area of necrotic tissue. - the infarct is converted into an abscess, with a correspondingly greater inflammatory response
FACTORS THAT INFLUENCE DEVELOPMENT OF AN INFARCT
- nature of the vascular supply
- rate of development of the occlusion (collateral circulation )
- vulnerability to hypoxia - Neurons undergo irreversible damage
- 3 to 4 minutes of ischemia. - Myocardial cells die after only 20 to 30 minutes of ischemia
- the oxygen content of blood
Assessing New Attachment in Periodontal Therapy
PeriodontologyAssessing New Attachment in Periodontal Therapy
Assessing new attachment following periodontal therapy is crucial for
evaluating treatment outcomes and understanding the healing process. However,
various methods of assessment have limitations that must be considered. This
lecture will discuss the reliability of different assessment methods for new
attachment, including periodontal probing, radiographic analysis, and histologic
methods.
1. Periodontal Probing
Assessment Method: Periodontal probing is commonly used
to measure probing depth and attachment levels before and after therapy.
Limitations:
Coronal Positioning of Probe Tip: After therapy,
when the inflammatory lesion is resolved, the probe tip may stop coronal
to the apical termination of the epithelium. This can lead to misleading
interpretations of attachment gain.
Infrabony Defects: Following treatment of infrabony
defects, new bone may form so close to the tooth surface that the probe
cannot penetrate. This can result in a false impression of improved
attachment levels.
Interpretation of Results: A gain in probing
attachment level does not necessarily indicate a true gain of connective
tissue attachment. Instead, it may reflect improved health of the
surrounding tissues, which increases resistance to probe penetration.
2. Radiographic Analysis and Reentry Operations
Assessment Method: Radiographic analysis involves
comparing radiographs taken before and after therapy to evaluate changes in
bone levels. Reentry operations allow for direct inspection of the treated
area.
Limitations:
Bone Fill vs. New Attachment: While radiographs can
provide evidence of new bone formation (bone fill), they do not document
the formation of new root cementum or a new periodontal ligament.
Therefore, radiographic evidence alone cannot confirm the establishment
of new attachment.
3. Histologic Methods
Assessment Method: Histologic analysis involves
examining tissue samples under a microscope to assess the formation of new
attachment, including new cementum and periodontal ligament.
Advantages:
Validity: Histologic methods are considered the
only valid approach to assess the formation of new attachment
accurately.
Limitations:
Pre-Therapy Assessment: Accurate assessment of the
attachment level prior to therapy is essential for histologic analysis.
If the initial attachment level cannot be determined with certainty, it
may compromise the validity of the findings.
Vitamin B12: Cobalamin
Biochemistry
Vitamin B12: Cobalamin
Vitamin B12, also known as cobalamin, aids in the building of genetic material, production of normal red blood cells, and maintenance of the nervous system.
RDA The Recommended Dietary Allowance (RDA) for vitamin B12 is 2.4 mcg/day for adult males and females
Vitamin B12 Deficiency
Vitamin B12 deficiency most commonly affects strict vegetarians (those who eat no animal products), infants of vegan mothers, and the elderly. Symptoms of deficiency include anemia, fatigue, neurological disorders, and degeneration of nerves resulting in numbness and tingling.