No abstract available.
Neck*

No abstract available.
Neck*

PURPOSE: The purpose of this study was to evaluate the fracture strength of straight and angled zirconia abutments for internal hex and external hex implants. MATERIALS AND METHODS: Twenty internal hex implants and 20 external hex implants were prepared. The prefabricated straight zirconia abutments and 17-degree-angled zirconia abutments were connected to those 40 implants. The specimens were classified into 4 groups depending on the connection type and abutment angulation; internal hex implant/straight abutment, group INS; internal hex implant/angled abutment, group INA; external hex implant/straight abutment, group EXS; external hex implant/angled abutment, group EXA. All specimens were loaded at a 30-degree angle with a crosshead speed of 1 mm/min using universal testing machine. The fracture loads were analyzed using 2-way ANOVA and independent t-test (α= .05). RESULTS: The mean fracture load for INS was 955.91 N, 933.65 N for INA, 1267.20 N for EXS, and 1405.93 N for EXA. External hex implant showed a significantly higher fracture load, as compared to internal hex implant (P < .001). No significant differences in fracture loads were observed between the straight and angled abutment in internal hex implants (P = .747) and external hex implants (P = .222). Internal hexes of abutments were fractured horizontally in internal connection implants, while lingual cervical neck portions were fractured in external connection implants. CONCLUSION: The zirconia abutments with external hex implants showed significantly higher fracture strength than those with internal hex implants. However there was no difference in fracture strength between the straight and 17-degree-angled zirconia abutment connected to both implant systems.
Neck

Anterior and posterior parallel opposed field technique covering entire neck is desirable for elimination of junctional problems in treating upper neck with bilateral parallel opposed fields and lower neck with anterior one field. For good dose distribution in neck, dose in build-p region should be high for anterior field and should be low for posterior field. And so, with 10 MV X-ay, lead absorber was used for anterior field only. The adequate thickness of lead absorber, absorber-kin separation, width of central cord block for posterior field and anterior & posterior field weight were studied using film dosimery. The results are as follows. 1. As the thickness of the lead absorber increased the dose in build-p region increased. 2. As the absorber-kin separation decreased the dose in build-p region increased. 3. The adequate thickness of lead absorber was around 5.6mm. 4. The adequate absorber-kin separation was around 5cm. 5. The adequate posterior cord block width was 3cm. 6. 4:1 weighting for anterior and posterior field was adequate. And so with this technique, adequate dose distribution could be made as well as elimination junction problems.
Neck*

No abstract available.
Neck*

No abstract available.
Neck*

No abstract available.
Neck*

No abstract available.
Neck*

Penetrating vascular trauma to zone one of the neck is potentially life-threatening. Trauma in this anatomical location is difficult to access and manage because the neck is a small anatomic area with the anatomical proximity of vital structures. An accurate diagnosis and aggressive surgical intervention are critical to the successful outcome of penetrating zone one vascular trauma in the neck. Here we report two cases with review of the medical literature.
Neck

No abstract available.
Neck*