Three-dimensional analysis of positional plagiocephaly before and after molding helmet therapy in comparison to normal head growth.
OBJECTIVE
Stereophotogrammetry enables a simple and radiation free longitudinal analysis of skull asymmetries: in a three-dimensional coordinate system various distances (length, breadth, cephalic index, oblique diameters, ear shift, head circumference) can be analyzed. We also defined separate volume sections in order to further quantify the degree of asymmetry in the posterior and anterior components of both sides of the head.


METHODS
In 51 infants (mean age, 6 months; SD 0.97) with positional plagiocephaly, we determined these parameters at the beginning as well as at the end of molding helmet therapy (mean therapy time 4.9 months). Thirty-seven infants without positional deformity (mean age, 6.4 months; SD 0.3) served as control group and provided data about what appears to be normal and how these parameters change during growth over a comparable period of time.


RESULTS
Compared with the control group, the plagiocephalic heads were more brachycephalic, but closely approximated the normal shape under molding therapy. The striking volume difference between the left and right posterior sections in the plagiocephalic children (the mean volume of the flattened side being 21% smaller than the one on the contralateral side) improved as well (to a residual difference of mean 8%) and ended up with a value close to the control group (mean 6%).


CONCLUSIONS
There is a broad clinical application area for stereophotogrammetry analyzing skull morphology: In plagiocephalic infants we demonstrate impressive changes of head shape under molding therapy; in normal-looking infants we describe the extent of unperceived asymmetry.
Department of Pediatric Neurosurgery, Craniofacial Center, University of Würzburg, Josef-Schneider-Strasse 11, 97080, Würzburg, Germany. schweitzer.t@nch.uni-wuerzburg.de.
Tilmann
T
Schweitzer
Department of Maxillo-Facial-Surgery and Plastic Surgery, Craniofacial Center, University of Würzburg, Würzburg, Germany.
Hartmut
H
Böhm
Department of Maxillo-Facial-Surgery and Plastic Surgery, Craniofacial Center, University of Würzburg, Würzburg, Germany.
Christian
C
Linz
Department of Pediatric Neurosurgery, University of Würzburg, Josef-Schneider-Strasse 11, 97080, Würzburg, Germany.
Beatrice
B
Jager
Department of Pediatric Neurology, University Childrens Hospital, Würzburg, Germany.
Lucia
L
Gerstl
Department of Orthodontics, Craniofacial Center, University of Würzburg, Würzburg, Germany.
Felix
F
Kunz
Department of Orthodontics, University of Würzburg, Würzburg, Germany.
Angelika
A
Stellzig-Eisenhauer
Department of Neurosurgery, University of Würzburg, Josef-Schneider-Strasse 11, 97080, Würzburg, Germany.
Ralf-Ingo
RI
Ernestus
Department of Pediatric Neurosurgery, University of Würzburg, Josef-Schneider-Strasse 11, 97080, Würzburg, Germany.
Jürgen
J
Krauß
Department of Orthodontics, Craniofacial Center, University of Würzburg, Würzburg, Germany.
Philipp
P
Meyer-Marcotty
D016022:Case-Control Studies; D002508:Cephalometry; D005260:Female; D006260:Head Protective Devices; D006801:Humans; D021621:Imaging, Three-Dimensional; D007223:Infant; D008297:Male; D009989:Orthotic Devices; D010780:Photogrammetry / Q000379:methods*; D049068:Plagiocephaly, Nonsynostotic / Q000628:therapy*; D016896:Treatment Outcome
Molding helmet; Positional plagiocephaly; Stereophotogrammetry; Unperceived asymmetry