Case-specific Questions Flashcards
Why FPD instead of RPDs?
patient did not want RPD
Caries rate of FPD vs. RPD?
RESEARCH
1) look at survival rate of abutment teeth in both scenarios
2) look at rate of recurrent caries in both scenarios
Recurrent caries is the second most likely case of FPD failure.
Plaque buildup around abutment teeth is common in FPDs
Why did you choose zirconia instead of metal-ceramic?
RESEARCH
Coello (2023) - An in vitro trial on the effect of arch form on connector size requirements in long span anterior zirconia fixed dental prostheses
Parameters for designing zirconia FPD??
RESEARCH
Coello (2023) - An in vitro trial on the effect of arch form on connector size requirements in long span anterior zirconia fixed dental prostheses
Ogino (2016) - Effect of Connector Design on Fracture Resistance in Zirconia-based Fixed Partial Dentures for Upper Anterior Region
Chong (2014) - Fracture force of cantilevered zirconia frameworks: an in vitro study
Lopez-Suarez (2019) - Effect of Thermomechanical and Static Loading on the Load to Fracture of Metal-Ceramic, Monolithic, and Veneered Zirconia Posterior Fixed Partial Dentures
Poppel (2022).- Fracture Load and Fracture Patterns of Monolithic Three-Unit Anterior Fixed Dental Prostheses after In Vitro Artificial Aging-A Comparison between Color-Gradient and Strength-Gradient Multilayer Zirconia Materials with Varying Yttria Content
ElShamoty (2024) - Effect of connector height and retainer occlusal thickness on the fracture resistance of posterior 4-unit monolithic 5Y-TZP fixed partial dentures after thermomechanical aging
Takuma (2013) - Effect of framework design on fracture resistance in zirconia 4-unit all-ceramic fixed partial dentures
Does a scanned or PVS impression produce better marginal fit for zirconia FPDs?
Marginal discrepancy in a conventional method was higher than the scanned method, but not significant. (Kalantari, 2023)
Why not veneer the zirconia?
Increased instance of fracture
- Bidra??
Veneering can lead to deterioration in fit
- Abduo (2010) - Fit of zirconia fixed partial denture: a systematic review
What type of LeFort osteotomy was this?
based on the location of the fixation screws and plates, it appears to be a LeFort I
Surgical boundaries of one-piece LeFort I
maxilla sectioned above apices of teeth but below nasal bones
through nasal septum
completing in disjunction of the pterygomaxillary junction
Why would a surgeon perform a segmented LeFort instead of one piece?
Segmentation is more common when the presurgical orthodontia is suboptimally leveled, aligned, and coordinated, which is more common in the cleft palate patient.
Indications and sectioning boundaries for 2-piece LeFort I
Indication:
- advancement alone does not correct the transverse discrepancy
Sectioning:
- typically section between central incisors
- in the cleft patient, it is reasonable to instead section at the alveolar cleft site
Indications and sectioning boundaries for 3-piece LeFort I
Indications:
- cleft lip & palate or craniofacial patient with midfacial hypoplasia in the anteroposterior dimension (acute SNA - sella-nasion-A point)
- class III malocclusion with suboptimal leveling, aligning, and coordination (more common in cleft patients)
Sectioning:
- typically section between lateral and canine bilaterally
- in the cleft patient, it is reasonable to section at the alveolar cleft site (which is usually in about the same place)
What is a potential risk of performing LeFort in a cleft patient vs. a non-cleft patient?
blood supply to the maxilla may be less abundant and predictable due to previous surgical interventions
Le Fort I vs. Le Fort II vs. Le Fort III
Le Fort I: horizontal fx resulting in mobility of maxilla
Le Fort II: pyramidal fx resulting in mobility of maxilla and nasal bones (through nasal-orbital-ethmoid area and nasofrontal bone)
Le Fort III: craniofacial disjunction fx resulting in mobility of maxilla, nasal bone, & zygomas (fx in pterygoid process and zygomatic arch)
What are the two main symptoms of oronasal fistula?
nasal regurgitation
hypernasality
Describe hypernasality
excessive nasal resonance typically on:
- vowels (u and i are most susceptible)
- glides (y, qu),
- liquids (l, r)
- in severe cases, voiced oral consonants (b, d, g)
