NEET MDS Synopsis
Psoriasis
General Pathology
Psoriasis
1. Characterized by skin lesions that appear as scaly, white plaques.
2. Caused by rapid proliferation of the epidermis.
3. Autoimmune pathogenesis; exact mechanism is unclear.
Flossing
PeriodontologyFlossing Technique
Flossing is an essential part of oral hygiene that helps remove plaque and
food particles from between the teeth and along the gumline, areas that
toothbrushes may not effectively clean. Proper flossing technique is crucial for
maintaining gum health and preventing cavities.
Flossing Technique
Preparation:
Length of Floss: Take 12 to 18 inches of dental
floss. This length allows for adequate maneuverability and ensures that
you can use a clean section of floss for each tooth.
Grasping the Floss: Hold the floss taut between
your hands, leaving a couple of inches of floss between your fingers.
This tension helps control the floss as you maneuver it between your
teeth.
Inserting the Floss:
Slip Between Teeth: Gently slide the floss between
your teeth. Be careful not to snap the floss, as this can cause trauma
to the gums.
Positioning: Insert the floss into the area between
your teeth and gums as far as it will comfortably go, ensuring that you
reach the gumline.
Flossing Motion:
Vertical Strokes: Use 8 to 10 vertical strokes with
the floss to dislodge food particles and plaque. Move the floss up and
down against the sides of each tooth, making sure to clean both the
front and back surfaces.
C-Shaped Motion: For optimal cleaning, wrap the
floss around the tooth in a C-shape and gently slide it beneath the
gumline.
Frequency:
Daily Flossing: Aim to floss at least once a day.
Consistency is key to maintaining good oral hygiene.
Best Time to Floss: The most important time to
floss is before going to bed, as this helps remove debris and plaque
that can accumulate throughout the day.
Flossing and Brushing:
Order of Operations: Flossing can be done either
before or after brushing your teeth. Both methods are effective, so
choose the one that fits best into your routine.
Mouth Protectors
Dental Materials
Mouth Protectors
Use - to protect against effects of blows to chin, top of the head, the face, or grinding of the teeth
Types
o Stock protectors-least desirable because of poor fit
o Mouth-formed protectors-improved fit compared with stock type
o Custom-made protectors-preferred because of durability. low speech impairment, and comfort
I. Components
a. Stock protectors-thermoplastic copolymer of PYA-PE (polyvinyl acetate-polyethylene copolymer)
b. Mouth-formed protectors-thermoplastic copolymer
c. Custom-made protectors- thermoplastic copolymer, rubber. or polyurethane
2. Reaction-physical reaction of hardening during cooling
3. Fabrication
Alginate impression made of maxillary arch. High-strength stone cast poured immediately. Thermoplastic material is heated in hot water and vacuum-molded to cast .
Mouth protector trimmed to within ½ inch of labial fold, clearance provided at the buccal and labial frena, and edges smoothed by flaming. Gagging, taste, irritation. and impairment of speech are minimized with properly fabricated appliances
4. Instructions for use
a. Rinse before and after use with cold water
b. Clean protector occasionally with soap and cool water
c. Store the protector in a rigid container
d. Protect from heat and pressure during storage
e. Evaluate protector routinely for evidence of deterioration
Properties
1. Physical-thermal insulators
2. Chemical-absorbs after during use
3. Mechanical-tensile strength, modulus, and hardness decrease after water absorption, but elongation, tear strength, and resilience increase
4. Biologic-nontoxic as long as no bacterial, fungal, or viral growth occurs on surfaces between uses
The Temporal Bones
Anatomy->The sides and base of the skull are formed partly by these bones.
->Each bone consists of four morphologically distinct parts that fuse during development (squamous, petromastoid, and tympanic parts and the styloid process).
->The flat squamous part is external to the lateral surface of the temporal lobe of the brain.
->The petromastoid part encloses the internal ear and mastoid cells and forms part of the base of the skull.
->The tympanic part contains the bony passage from the auricle (external ear), called the external acoustic meatus. The petromastoid part also forms a portion of the bony wall of the tympanic cavity (middle ear). The meatus and tympanic cavity are concerned with the transmission of sound waves.
->The slender, pointed styloid process of the temporal bone gives attachment to certain ligaments and muscles (e.g., the stylohyoid muscle that elevates the hyoid bone).
->The temporal bone articulates at sutures with the parietal, occipital, sphenoid, and zygomatic bones.
->The zygomatic process of the temporal bone unites with the temporal process of the zygomatic bone to form the zygomatic arch. The zygomatic arches form the widest part of the face.
->The head of the mandible articulates with the mandibular fossa on the inferior surface of the zygomatic process of the temporal bone.
->Anterior to the mandibular fossa is the articular tubercle.
->Because the zygomatic arches are the widest parts of the face and are such prominent facial features, they are commonly fractured and depressed. A fracture of the temporal process of the zygomatic bone would likely involve the lateral wall of the orbit and could injure the eye.
AGE CHANGES of the Periodontal Ligament (PDL)
Dental Anatomy
AGE CHANGES
Progressive apical migration of the dentogingival junction.
Toothbrush abrasion of the area can expose dentin that can cause root caries and tooth mobility.
Histology of the alveolar bone
Near the end of the 2nd month of fetal life, mandible and maxilla form a groove that is opened toward the surface of the oral cavity.
As tooth germs start to develop, bony septa form gradually. The alveolar process starts developing strictly during tooth eruption.
The alveolar process is the bone that contains the sockets (alveoli) for the teeth and consists of
a) outer cortical plates
b) a central spongiosa and
c) bone lining the alveolus (bundle bone)
The alveolar crest is found 1.5-2.0 mm below the level of the CEJ.
If you draw a line connecting the CE junctions of adjacent teeth, this line should be parallel to the alveolar crest. If the line is not parallel, then there is high probability of periodontal disease.
Bundle Bone
The bundle bone provides attachment to the periodontal ligament fibers. It is perforated by many foramina that transmit nerves and vessels (cribiform plate). Embedded within the bone are the extrinsic fiber bundles of the PDL mineralized only at the periphery. Radiographically, the bundle bone is the lamina dura. The lining of the alveolus is fairly smooth in the young but rougher in the adults.
Clinical considerations
Resorption and regeneration of alveolar bone
This process can occur during orthodontic movement of teeth. Bone is resorbed on the side of pressure and opposed on the site of tension.
Osteoporosis
Osteoporosis of the alveolar process can be caused by inactivity of tooth that does not have an antagonist
VITAMIN -K
Pharmacology
VITAMIN -K
Group of lipophilic, hydrophobic vitamins.
Needed for the post-translational modification of coagulation proteins.
Phylloquinone (vitamin K1) is the major dietary form of vitamin K.
Vitamin K2 (menaquinone, menatetrenone) is produced by bacteria in the intestines.
The Superior Roof of the Orbit
AnatomyThe Superior Roof of the Orbit
The superior wall or roof of the orbit is formed almost completely by the orbital plate of the frontal bone.
Posteriorly, the superior wall is formed by the lesser wing of the sphenoid bone.
The roof of the orbit is thin, translucent, and gently arched. This plate of bone separates the orbital cavity and the anterior cranial fossa.
The optic canal is located in the posterior part of the roof.
Extraction Patterns for Presurgical Orthodontics
Oral and Maxillofacial SurgeryExtraction Patterns for Presurgical Orthodontics
In orthodontics, the extraction pattern chosen can significantly influence
treatment outcomes, especially in presurgical orthodontics. The extraction
decisions differ based on the type of skeletal malocclusion, specifically Class
II and Class III malocclusions. Here’s an overview of
the extraction patterns for each type:
Skeletal Class II Malocclusion
General Approach:
In skeletal Class II malocclusion, the goal is to prepare the dental
arches for surgical correction, typically involving mandibular
advancement.
Extraction Recommendations:
No Maxillary Tooth Extraction: Avoid extracting
maxillary teeth, particularly the upper first premolars or any maxillary
teeth, to prevent over-retraction of the maxillary anterior teeth.
Over-retraction can compromise the planned mandibular advancement.
Lower First Premolar Extraction: Extraction of the
lower first premolars is recommended. This helps:
Level the arch.
Correct the proclination of the lower anterior teeth, allowing
for better alignment and preparation for surgery.
Skeletal Class III Malocclusion
General Approach:
In skeletal Class III malocclusion, the extraction pattern is
reversed to facilitate the surgical correction, often involving
maxillary advancement or mandibular setback.
Extraction Recommendations:
Upper First Premolar Extraction: Extracting the
upper first premolars is done to:
Correct the proclination of the upper anterior teeth, which is
essential for achieving proper alignment and aesthetics.
Lower Second Premolar Extraction: If additional
space is needed in the lower arch, the extraction of lower second
premolars is recommended. This helps:
Prevent over-retraction of the lower anterior teeth, maintaining
their position while allowing for necessary adjustments in the arch.