Endoscopically assisted craniosynostosis surgery (EACS): The craniofacial team Nijmegen experience.

INTRODUCTION: An evaluation of our first 111 consecutive cases of non-syndromic endoscopically assisted craniosynostosis surgery (EACS) followed by helmet therapy. METHODS: Retrospective analysis of a prospective registration database was performed. Age, duration of surgery, length of hospital stay, blood loss, transfusion rate, cephalic index and duration of helmet therapy were evaluated. An online questionnaire was used to evaluate the burden of the helmet therapy for the child and parents. RESULTS: 111 EAC procedures were performed: 64 for scaphocephaly, 34 for trigonocephaly and13 for anterior plagiocephaly. The mean age at the time of surgery was 3.9 (±1) months, mean surgical time was 58 (±18) minutes, mean blood loss was 34 (±28) ml, transfusion rate was 22% (n = 26), mean duration of postoperative helmet therapy was 10 (±2.5) months, mean preoperative and postoperative CI were respectively 0.67(±0.057) and 0.72 (±0.062) in scaphocephalic patients and the mean length of hospital stay was 2.6 (±1) days. The burden of the helmet therapy for the child and his family was deemed very low. CONCLUSION: EACS for non-syndromic patients shows low morbidity rates, short surgical time, short length of hospital stay, little blood loss and low need for blood transfusion and is associated with satisfying cosmetic results.

Accuracy of bone surface size and cortical layer thickness measurements using cone beam computerized tomography.

OBJECTIVES: The purpose of this study was to determine the accuracy of Cone Beam Computerized Tomography (CBCT) reconstructions in displaying bone surface size and cortical layer thickness. MATERIALS AND METHODS: Two fresh frozen cadaver heads were scanned using a CBCT (i-CAT(™) 3D Imaging System; Imaging Sciences International Inc.). The mandibles were sectioned and digitalized for histological evaluation. Dimensions as measured on these sections were compared with CBCT measurements of the same region with the use of 3D image-based planning software (Procera System NobelGuide(™); Nobel Biocare). To allow optimal comparison between histological and CBCT sections, reference markers were placed into the mandibles. The Student t-test was utilized to analyze the data. Differences with P-values <0.05 were considered significant. RESULTS: The total height and width of the mandibular body, as measured on CBCT views, were larger compared with the histological values with a maximum difference of 0.33 mm (SD ± 0.34). Cortical thickness measurements were significantly thicker on CBCT sections (P < 0.006) with absolute differences ranging up to ±0.63 mm (SD ±0.28) and relative differences ranging up to 82.6%. CONCLUSION: CBCT images (i-CAT 3D Imaging System), viewed on the planning software Procera System NobelGuide, tend to overestimate the anatomical truth in assessing both bone height and width; especially cortical thicknesses are depicted thicker than in reality. When using CBCT images for presurgical assessment, one should be aware of this phenomenon of exaggeration of dimensions.