Distinguishing Craniomorphometric Characteristics of Unilateral Lambdoid Craniosynostosis

Abstract

Background: Unilateral lambdoid synostosis (ULS) represents the rarest form of single suture nonsyndromic craniosynostosis. Differentiating between posterior deformational plagiocephaly (DP) and ULS has been difficult due to overlapping clinical findings. Past analyses have been limited by sample size. This study was undertaken to clarify anatomical features of ULS. Methods: A multiinstitution study was undertaken, analyzing CT imaging from patients with documented ULS to determine clinical and pathological characteristics. Similar analyses were performed on DP patients to differentiate the 2 conditions. Results: Twenty-seven ULS patient scans and 10 DP scans were included. For ULS patients mean age was 6.6 months, majority male (75%), and majority left-sided ULS (71%). The synostosed side ear was anteriorly displaced in 100% of ULS patients, mean difference of 9.6° (P < 0.001), and inferiorly in 96.3% of patients, mean difference of 4.4 mm, relative to the nonsynostosed side. The posterior fossa deflection (PFD) was deviated 5.9° toward the synostosed side relative to the anterior midline. In DP, there was no significant difference between sides in EAC measurements. The PFD and EAC displacements were significantly smaller in DP relative to ULS (P < 0.001 for each). An ipsilateral mastoid bulge was found in 100% of ULS and 0% of DP on CT imaging. Conclusion: Contrary to some previously published findings, the ear is more anteriorly displaced ipsilateral to the fused lambdoid suture in 100% of ULS patients. Ear position alone is not a reliable indicator to differentiate between DP and ULS. A mastoid bulge is a more reliable indicator of ULS.

Utilizing Computer-Assisted Design and Virtual Surgical Planning for Correction of Unilateral Lambdoid Synostosis

“…Similar clinical findings between ULS and far more common nonsynostotic deformational plagiocephaly complicates prompt diagnosis. The presence of a mastoid bulge and inferior ear displacement have been suggested as the most specific findings in ULS 12. The rarity of the condition has also prevented consensus on optimal surgical technique.…”

“…The presence of a mastoid bulge and inferior ear displacement have been suggested as the most specific findings in ULS. 12 The rarity of the condition has also prevented consensus on optimal surgical technique. The use of custom cutting guides to create a neooccipital bandeau allows for a fixed step-off height that ensures symmetric occipital skull position.…”

“…Preoperative and postoperative craniometric measurements were made as described previously for ULS from the postoperative imaging 12. The ratio of the right and left anterior and middle cranial fossas remained unchanged (1.04 and 0.77, respectively), whereas the ratio of the posterior cranial fossa areas became nearly symmetrical (0.85–0.97) postoperatively (Fig.…”

Long-Term Results After Head Orthosis Therapy for Early Childhood Position-Related Cranial Deformities: Stability of Treatment Outcome and Parental Satisfaction

“…Thereby, the soft skullcap of the infant possess a tendency to deform 5,6 . Indications for treatment of the head deformity are delayed cognitive, motor, and linguistic development as well as the aesthetic appearance 7–10 . In the present literature only few articles concerning the long-term stability outcome after molding helmet therapy in children with deformational Plagiocephalus (DP) or deformational Brachycephalus (DB) or a combination of both are listed 11–13 .…”

“…5,6 Indications for treatment of the head deformity are delayed cognitive, motor, and linguistic development as well as the aesthetic appearance. [7][8][9][10] In the present literature only few articles concerning the long-term stability outcome after molding helmet therapy in children with deformational Plagiocephalus (DP) or deformational Brachycephalus (DB) or a combination of both are listed. [11][12][13] The purpose of the present study was to investigate changes in head shape depending on the initial diagnosis within the treatment time and in a period of 1 until 5 years after helmet therapy.…”