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International Journal of Bioprinting 3D-printed post-otoplasty ear retainer

Figure 3. 3D-printed personalized ear retainer for post-ear correction surgery. (A and D) A 3D-printed BioMed Flex 80A retainer (A) that conforms to
the patient’s auricular morphology (D), (B and E) the positioning cover printed with BioMed Clear Resin (B) and attached with a split-type retainer on
the patient’s auricle (E), (C and F) an outer shell printed with BioMed Clear Resin (C) and equipped with a soft headband that is comfortably worn on the
patient’s auricle (F), effectively protecting the internal structure.
uniform distribution patterns from the contour map of both The results of FEA indicated that the overall structure
contact stress and von Mises stress indicate good contact has good stability when worn. Changes in stress and
between the retainer and the skin. Notably higher stress strain suggest that the retainer mechanically supports
occurred near the helix, triangular fossa, antihelix, and the structures post-otoplasty and should be constantly
the upper and lower legs of the ear skin; the surrounding maintained. Otoplasty repairs the underdeveloped antihelix
ear skin exhibits relatively uniform stress distribution and obtuse concho-scaphal angle, and the postoperative
with lower stress values. The area behind the ear also mold for the scaphal and antihelical fossa on the back of
demonstrated higher localized stress, with peak values the ear is essential for maintaining the morphology. In
higher than the surrounding skin stress. This suggests that cryptotia corrective surgery, the upper part of the auricle
after wearing the retainer, most of the force is transferred (under the ear skin) and the auriculotemporal sulcus are
near the helix, triangular fossa, antihelix, and the superior restored, supporting the auriculotemporal sulcus.
crus and inferior crus, with stress diffusion around the 3.4. Clinical validation
ear being relatively uniform or lower. Moreover, the The satisfaction of patients wearing the retainer was assessed,
structure of the retainer also withstands the pressure to and the findings are presented in Table 3. Most participants
resist deformation towards the back of the ear, resulting in were “satisfied” or “very satisfied” with the retainer (n = 17;
higher localized stress areas. 85%). The highest satisfaction was reported for “safety”

Volume 10 Issue 5 (2024) 469 doi: 10.36922/ijb.3986