A new method of determining facial size for three-dimensional photogrammetry quantification
Nova metoda določanja velikosti obraza v tridimenzionalni fotogrametriji

M. Verdenik, N. Ihan Hren, Ž. Kadivnik, I. Drstvenšek
2021 Materiali in Tehnologije  
Contemporary craniofacial surgery includes the pre-and post-operative optical 3D scanning of faces as a method for diagnosing and verifying the achieved results. The influence of head size in 3D scans must be excluded in order to accurately and uniformly compare different three-dimensional facial shapes in craniofacial surgery. Regarding this purpose, different head-size parameters must be measured to obtain the scaling factor. A special device, a so-called head ring, has been produced as a
more » ... n produced as a structure that can be fixed to a person's head. Among defined points, different linear distances (head width, length and height) and volumetric parameters (lower and upper head volumes) were calculated and compared to body-size measurements. Measurements were performed on 3D scans of the heads of 26 healthy adults with normocclusion (12 men and 14 women) taken using the head ring set. Body mass index (BMI) statistically significantly correlates with the lower and whole-head volume in men, while in women more precisely with the upper-head volume. BMI in men does not correlate with any linear distance, while in women it is closely connected to the facial width. In men the head width and lower head volume are the main contributors to head size, while in women the crown-to-chin length and upper volume determine the size of the head. A conclusion can be made that the correlation between the head volume, the BMI and the linear head parameters exists and is gender dependent. Na podro~ju karniofacialne kirurgije so vedno bolj uveljavljene 3D-metode, med njimi tudi neinvazivni povr{inski posnetki glave in obraza. Za natan~no primerjavo 3D-posnetkov razli~nih obrazov med seboj, je potrebno izkllju~iti vpliv velikosti glave in obraza. Za namen bolj objektivne registracije, je bil izdelan poseben pripomo~ek, ki smo ga poimenovali naglavni obro~. Z njegovo uporabo smo pridobili dodatne podatke, kot so: razdalja med u{esi, razdalja med najvi{jo to~ko glave in brado, razdalja med navideznim sredi{~em in bazo nosu ter s pomo~jo markerjev izmerjeni volumen spodnje in zgornje piramide ter volumen elipsoida, ki ga markerji opi{ejo. Dodatno je mo'no, kot parameter dolo~anja velikosti obraza, uporabiti tudi indeks glave (kot analog obraznemu indeksu) izra~unan kot razmerje med obrazno dol'ino in {irino. Meritve so bile izvedene na 26 zdravih preiskovancih brez skeletnih in zobnih nepravilnosti (12 mo{kih in 14'enskah). ITM (indeks telesne mase) je zna~ilno koreliral z volumnom spodnje obrazne piramide in celotnim volumnom pri mo{kih preiskovancih, pri'enskah pa z volumnom zgornje piramide. ITM pri mo{kih ni imel zna~ilne povezave z opazovanimi linearnimi razdaljami, pri'enskah pa smo na{li povezavo z razdaljo med u{esi. Pri mo{kih smo ugotovili, da k velikosti glave najbolj prispevata razdalja med u{esi in volumen spodnje piramide, pri'enskah pa razdalja med najvi{jo to~ko glave in brado ter volumen zgornje piramide. Ugotovljene so bile zna~ilne povezave med ITM, spolom in nekaterimi obraznimi parametri, ki smo jih dolo~ili s pomo~jo naglavnega obro~a.
doi:10.17222/mit.2020.113 fatcat:exv3dfwpt5bvlpzxcr5hgztq54