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Selected Publication:
Bruneder, S.
Anatomy of the Le Fort I Segment:
Are arterial variations a potential risk factor for avascular bone necrosis in Le Fort I osteotomies?
Zahnmedizin; [ Diplomarbeit/Master Thesis (UNI) ] Graz Medical University; 2018. pp.42.
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- Authors Med Uni Graz:
- Bruneder Simon
- Advisor:
- Weiglein Andreas
- Zemann Wolfgang
- Altmetrics:
- Abstract:
- Background and objectives: Osteotomies of the Le Fort I segment are routine operations in orthognathic surgery with low complication rates. In this context ischemic complications are, with an occurrence of about 1% rare, but can have severe consequences. These ischemic complications range from gingival retraction and/or loss of tooth vitality to avascular bone necrosis of the mobilized Le Fort I segment. Anatomically the blood supply of the Le Fort I segment is mainly based on the ascending palatine, the ascending pharyngeal, the descending palatine artery and smaller arteries that reach the alveolar process from the buccal side. The aim of this study was to investigate the blood supply and special arterial variants of the Le Fort I segment responsible for arterial hypoperfusion or ischemic avascular necrosis after surgery. Material and methods: A total of 30 halved human cadaver head specimens, preserved with a high-quality embalming method were selected according to defined inclusion and exclusion criteria. All specimens were subjected to arterial latex injection for improved visibility. The arterial anatomy of the Le Fort I segment was analyzed after the ascending palatine and ascending pharyngeal arteries were completely dissected until the submicroscopic level by clinical and anatomical specialists. Dissection was performed using surgical standard methods and a dissection microscope. In all specimens the arterial variants of the Le Fort I segment as also the arterial diameters measured at two points (D1: origin and D2: palate-entry of artery) were evaluated to categorize the occurring types of arterial variations. Results: The typical known palatine vascularization pattern was apparent in 90% of all specimens, in which the ascending palatine artery (D1: 1,2mm ± 0,34mm; D2: 0,8mm ± 0,34mm) and ascending pharyngeal artery (D1: 1,3mm ± 0,58mm; D2: <0,4mm) were both supplying the Le Fort I segment. However in 10% of all specimens, the Le Fort I segment was dependent on the ascending pharyngeal artery alone. In these special cases the missing ascending palatine artery was replaced with the anterior branch of the ascending pharyngeal artery (D1: 1,9mm ± 0,32; D2: 1,0mm ± 0,3mm). Conclusion: This study is the first description of a special type of arterial variation of the Le Fort I segment which occurred in 10% of the investigated cases. The type of this arterial variation, potential risk factors and resulting clinical consequences accompanied with the variation are explained. Individuals with this special variant of arterial anatomy may clinically be at a high risk of hypoperfusion and avascular necrosis of the Le Fort I segment due to surgical procedures and segment mobilization. An individualized operation plan that considers the arterial anatomy may prevent ischemic avascular complications in at-risk patients.