BDS4 Oral Surgery PPs Flashcards
What foramen does the ophthalmic branch of CNV pass through?
Superior orbital fissure
What foramen does the maxillary branch of CNV pass through?
Foramen rotundum
What foramen does the mandibular branch of CNV pass through?
Foramen ovale
What is the origin, insertion, innervation & function of the masseter?
Origin = zygomatic process of maxilla (superficial head) & zygomatic arch (deep head)
Insertion = ramus + angle of mandible
Innervation = masseteric nerve of CNV3
Function = Elevation of mandible
What is the origin, insertion, innervation & function of the Temporalis?
Origin = floor of temporal fossa
Insertion = coronoid process & ramus of mandible
Innervation = deep temporal nerves of CNV3
Function = Elevation of mandible, retraction of mandible
What is the origin, insertion, innervation & function of the Medial Pterygoid?
Origin = medial surface of lateral pterygoid plate & maxillary tuberosity
Insertion = medial surface of angle of mandible
Innervation = medial pterygoid nerve of CNV3
Function = Elevation of mandible, protrusion of mandible, side to side movements
What is the origin, insertion, innervation & function of the Lateral Pterygoid?
Origin = greater wing of sphenoid bone (superficial head) & lateral pterygoid plate (deep head)
Insertion = articular disc of TMJ & neck of mandibular condyle
Innervation = lateral pterygoid nerve of CNV3
Function = protrusion, lateral movement, stabilisation of TMJ
What is the histopathology of a squamous cell carcinoma?
- Increased mitotic activity
- Cellular atypia
- Abnormal keratinisation
- Pleomorphism
- Basal cell hyperplasia
- Disturbed polarity of cells
Patient attends with a right body mandibular fracture.
Other than pain, bruising & swelling, list 6 other signs and symptoms of mandibular fractures:
- Step deformity
- Facial asymmetry
- Occlusal derangement
- Sublingual haematoma/bleeding
- Numbness of lower lip
- AOB
Patient attends with a right body mandibular fracture.
What factors cause displacement of mandibular fractures?
- Direction of fracture line
- Opposing occlusion
- Magnitude of force applied
- Mechanism of injury
- Soft tissue status (intact or not)
- Other associated fractures
Patient attends with a right body mandibular fracture.
What does displacement of fragments depend on?
- Pull of attached muscles
- Angulation and direction of fracture line
- Integrity of periosteum
- Extent of communication
What anaesthetic is not recommended for pregnant patients?
Citanest [contains Felypressin which can induce labour]
What type of joint is the TMJ?
synovial, hinge type joint
What artery supplies the TMJ?
Branches of the external carotid:
- superficial temporal artery
- deep auricular artery
- ascending pharyngeal
- maxillary artery
What nerves supply the TMJ?
Innervated by:
- Auriculotemporal branch of CNV
- Masseteric branch of CNV
Disc displacement with reduction:
In terms of disc and condylar movement, describe how disc displacement with reduction occurs.
- Articular disc is displaced from normal position and moved anterior to the condyle
- When the jaw opens, the displaced disc “reduces” or snaps back into its normal position between condyle and fossa
- Associated with clicking or popping sound
- As jaw closes the disc can again displace anteriorly causing another click/pop
What is the risk of not treating disc displacement with reduction?
- May progress to a closed lock state
- Wear on the disc
Give 5 signs of Zygomatico-Orbital fracture:
- facial asymmetry
- periorbital ecchymosis
- subconjunctival haemorrhage
- numbness in infraorbital area
- step deformity of zygomatic arch
- flattened appearance
How would you clinically assess for a zygomatico-orbital fracture?
- visual inspection
- palpation of zygomatic arch/infraorbital rim/maxilla
- assessment of jaw movement & trismus
- test for sensory deficits in the infraorbital distribution
- check for visual diplopia
, restricted eye movement, displacement of eye
What radiographic views may be taken for a zygomatic-orbital fracture?
- CT scan
- OM radiograph 10 and 40 degrees
What INITIAL management should you consider for a zygomaticoorbital fracture?
- Analgesia and anti-inflammatories to control pain and swelling
- Consider antibiotics to eliminate infection
- Asses for additional injuries
- Ice to reduce swelling
What DEFINITIVE management should you consider for a zygomaticoorbital fracture?
If fracture is stable & non-displaced:
- Observation and conservative care
If displaced:
- Surgery via open reduction and internal fixation with pins and plates
What are the 5 radiographic signs of fractures?
- Sharply-defined radiolucent line/lines contained within the boundary of a bone
- Radiopaque line/area contained within the boundary of a bone (caused by overlap of bone
- Change in normal anatomical outline/shape of a bone or soft tissue [asymmetry]
- Opacification (i.e. ↑ radiopacity of contents) of paranasal sinuses
- Surgical emphysema (i.e. air within the soft tissues resulting in radiolucent areas)
What is a tripod fracture?
Zygomatic complex fracture that involves:
- zygomatic arch
- infraorbital rim
- lateral orbital rim
Give 3 methods for abscess drainage post incision:
- Irrigation and debridement
- Place a drain
- Open drainage
Give two common bacteria found in dentoalveolar infections. For each bacteria give the antibiotic effective against it:
Streptococcus Anginosus = penicillin (cell wall), clindamycin (protein synthesis)
Prevotella Intermedia = penicillin (cell wall), metronidazole (DNA synthesis)
How would you describe the key features of a swelling case to theConsultant over the telephone?
- Prior to phoning, ensure that you have all the patients details to hand.
- Ensure location for conversation is in a location that does not compromise patient confidentiality.
- Situation – patient, age, diagnosis(a severe spreading submandibular odontogenic infection)
- Background- Summarise the significant points in the patients history eg when/if extraction carried out, signs and symptoms since.
- Assessment- what have you found today? Any relevant E/O and I/O findings as well as results of observations. Be specific when giving a description of the pathology ie which anatomical location (landmarks), structures involved, size of lesion (avoid non-specific terms such as small/large).
- Recommendation- what you think should happen eg “I think this patient needs to be seen urgently as I’m concerned about their airway”
Despite effective antimicrobial activity against oral anaerobes, clindamycin is not routinely used instead of metronidazole. Why not?
- Risk of C. Difficile infection
- Metronidazole more targeted spectrum of activity against anaerobic bacteria
What 2 drugs are found in Co-Amoxiclav?
- Amoxicillin
- Clavulanic acid
EFFECTIVE AGAINST BETA LACTAMASE that is RESISTANT TO AMOXICILLIN
Co-amoxiclav may be used as a second choice antibiotic.
ii. When should it be given to patients instead of the standard second choice antibiotic?
Severe spreading infection with spreading cellulitis and where the infection is not responding to first line antimicrobials
State 3 red flags signs of sepsis:
- Systolic BP </= 90mmHg
- HR >/= 130bpm
- Respiratory rate >/= 25/min
You assess a patient and they have one sepsis red flag present. What must be done next?
- Dial 999 and state pt has red flag sepsis
- Start pt on oxygen to maintain saturation >94%
- Arrange blue light transfer to hospital
List the therapeutic indications for XLA of mandibular 3rd molars:
- Infection
- Caries in 3rd molar or adjacent teeth
- Periapical abscess
- Periodontal disease
- Cyst formation
- Tumour formation
What is the goal of marsupialisation of a cyst?
Creates a permanent opening in the cyst allowing continuous drainage and pressure release
- aim for cyst shrinkage
Give 5 reasons for failure of endodontic treatment:
- incomplete root canal filling
- missed canals [eg accessory canals]
- coronal leakage
- fractured instruments
- root fractures
Give 2 aims of periradicular surgery:
- Remove pathology and infection need root apex
- Create a sealed apical barrier to prevent ingress of microbes
What flap designs are used in periradicular surgery?
- Semilunar flap
- Mucoperiosteal full thickness 3 sided flap
Name 2 instruments used in root-end preparation of periradicular surgery:
- Ultrasonic tips
- Specialised endodontic handpieces
Name 3 retrograde root filling materials:
- MTA
- GI cement
- Amalgam
- Ethoxybenzoic Acid Cement
Give five reasons for failure of periradicular surgery:
- Inadequate root end seal
- Persistent aggressive infection or pathology
- Root fracture
- Inadequate surgical technique
- Patient has poor OH or fails to adhere to post op care
Give 3 reasons why a root may fracture during extraction:
- Extensive decay of tooth
- Poor extraction technique with excessive force
- Complex anatomy of root
Give 3 indications for leaving a root in situ:
- Close proximity to anatomical structures
- Risk of excessive trauma required to extract
- Pt cannot tolerate surgery
What is an OAC vs OAF?
OAC = acute open passage or communication between oral cavity and sinus
OAF = chronic opening that has become lined with epithelium, forms when OAC does not heal properly
Give 5 risk factors for development of OAC:
- XLA of posterior maxillary teeth
- Root in close proximity to sinus on radiograph
- Pre-existing sinus pathology
- Severe dental/maxillary trauma
- Poor XLA technique with excessive force
List three peri-operative signs of an OAC:
- Visible communication/hole
- Air bubbling/blood bubbling
- Whistling sound when pt breathes
List three post-operative signs of an OAC afte extractions:
- Nasal discharge when drinking
- Recurrent sinus infections
- Altered voice/nasal resonance tone to voice
Discuss three types of OAF closure methods:
- Buccal advancement flap [create buccal mucoperiosteal flap, advanced to cover hole]
- Palatal flap
- Buccal fat pad flap
Aside from surgery, what other management option exists for OAC pts?
Obturator
