Observing specialists

 Today I spent the day observing in the specialist clinics upstairs. I am in a transition period  with my part time private hours and am yet to start a teaching position so I still had the free weekday to do this. In the morning I watched in the OMFS clinic which was mainly post operative reviews and pre-surgical consultations. The students that were rostered to the OMFS rotation got the preference to watch in theatre so I didn't get any exposure there. Some things they mentioned were:

- Trauma signs: CSF leak will result in a halo sign i.e the fluid will have blood in the centre and clear CSF around it which resembles a halo

-With a vertical ramus fracture, displacement of the bone opening the fracture will be due to the lateral pterygoid and temporalis which pull in different directions whereas the masseter and medial pterygoid will act as a stabiliser

 - Titanium jaw plates will generally stay in situ for the rest of the patient's life but can occasionally show through and may need to be removed

-As part of a trauma ATLS survey, things you can't miss are C spine which will show midline tenderness or restriction to movement of the head to the side and up and down as well as cranial nerves especially trigeminal and facial as these are the most exposed in base of skull and back of skull injuries respectively. Test the trigeminal  by feeling the face bilaterally in V1, V2, V3 zones. Test the facial each zone at a time: raise the eyebrows (temporal), close their eyes firmly and smile (zygomatic), puff their cheeks out (buccal), pucker their lips looking at the lower lip (marginal mandibular), tense their platysma (cervical)

-Facial bone fractures can be assessed by feeling along the bones especially at the sutures which is the weak spots where they will fracture. Feeling along the orbital rim, at the zygomatic sutures, border of the mandible, wiggle the maxilla and feel intraorally for the zygomatic buttress.

-Medial orbital rim fractures are usually left alone if there is no proptosis or exopthlamos. They used an exophthalmeter to measure this. This was a horizontal bar placed in contact with the lateral orbital rim and lateral to the eyes were mirrors that allowed the user to view the side of the eye from the front. There was a measuring gauge which allowed the anterior-posterior position of the eye to be measured and as long as both sides are the same then surgery can be avoided. Any fracture involving the nasal airway e.g the medial orbital wall or zygomatic fracture they instructed them not to blow their nose or use CPAP/BiPAP machines for 4 weeks.

-Displaced zygomatic fractures generally present with limited mouth opening as it blocks the passage of the temporalis muscle sliding through and blocks the movement of the coronoid process anteriorly. Mild displacements can be reduced intraorally with a slit cut in the maxillary labial sulcus and an instrument used to lever the zygoma laterally.

-Bony fractures e.g mandible can wait up to 2 weeks to be reduecd. This is important in cases where more urgent problems are prioritised e.g C spine or the patient is intubated

- Sublingual hematoma is pathognomonic of a fracture of the mandible as there is bleeding into the sublingual space

In the afternoon I asked if I could watch in the perio and pros specialist department which they kindly obliged.

I was watching a full arch implant placement joint between periodontics and prosthodontics. A final year periodontics student was placing the implants under the guidance of a prosthodontist who did the planning and periodontist. A surgical guide was placed and screwed into tissue and the tissue marked through the holes to mark the future implant sites. The guide was removed and the markings used to guide the crestal incision slightly to the palatal and a buccal and palatal flap was raised. The osteotomy sites were drilled with the guide in place and the anterior 4 implants were placed through the guide. It is important to have the implant itself absolutely parallel to the guide cylinder or it may bind on the walls and stall due to the torque on the implant. As the implants were placed, they were started on low torque ~20 Ncm and as the torque limit was reached, they increased the torque of the motor controls to advance the implant further. This was to slowly advance the implant and not overstretch the bone. If the implant stalled at a high torque, they partially backed the implant out at a high torque and then advanced it back in at a lower torque. This continued multiple times with some of the implants as each motion slowly expanded the bone. 

Loading was planned immediately but as the surgery took much longer than planned (7 hours long planned for 4 hours) this was delayed to a couple of days later. The plan was to convert their full denture to a fixed prosthesis. This would be done by inserting temporary cylinders and picking them up with chairside acrylic. One of the molar implants had a palatal dehiscence and so biooss collagen was placed with a bioguide membrane to attempt to allow the palatal bone to fill the defect. Anteriorly, the implants placed in the sockets were left ungrafted as there was 2mm of bony envelope buccal to the implant surface which would allow bony infill. As the implant was grafted, the prosthodontist didn't want to load that implant and said he would cut the denture just distal to the more anterior implant.Loading has to be done within 1 week as the primary stability of the implants decrease after this due to bone resorption.

It was interesting observing a surgery from the outside as even the highly trained periodontics student was having difficulty with the complexity and length of the procedure. Simple tasks such as suturing, placement of one implant and grafting were clumbsier and took longer than normal as there were so many other things to consider. There was also an element of visual fatigue where obvious things were missed e.g tissue tags and periosteum that hadn't been raised because he had spent so long looking and focussing at fine details. This just serves to highlight the difficulty of any procedure that is lengthy and complex where individual parts would be simple but when put in sequence, the fatigue of our bodies and minds can get the better of us.

After this surgery I had a look at a review of some buildups that another prosthodontist did. She explained to me that as it was a hypodontia case and there weren't many teeth to build up she didn't bother with a waxup but took a putty key of some denture teeth that were the same mesiodistal width as the tooth she was building up. She filled the occlusal surface of these with flowable resin, very thin up to the marginal ridge and cured. She then removed this and it acted as a sort of "componeer" where she prepared the tooth for bonding, placed composite resin on the tooth and this templated flowable occlusal surface on top of this, manipulating it until it was at the right position then cured the whole lot. sort of like an indirect composite. If this was a larger case, she would consider building composite restorations on the model, sandblasting the fitting surface and cementing them with resin cement or flowable composite. 

I will see if they will allow me to observe in these clinics again before I start more work days and won't have the time to do so.