Comparison of Computed Tomographic Imaging Measurements with Clinical Findings in Children with Unilateral Lambdoid Synostosis

Abstract

Mastoid bossing, skull base cant, and inferior ear deviation ipsilateral to the fused sutures were clinical findings that were consistent with computed tomographic measurements in these patients. Trapezoid head shape and posterior ear deviation were not. Radiographic suture fusion was observed in all cases; however, the extent of fusion did not correlate with the degree of deformity.

The Variable Position of the Ear in Lambdoid Synostosis

“…Other diagnostic criteria (clinical and radiologic), however, can be used to secure the diagnosis. 2,3 Clinically, the most consistent feature of isolated unilateral lambdoid craniosynostosis seems to be the ipsilateral occipitomastoid bossing. Other methods, such as using the overall skull shape as a diagnostic tool, can be tricky, because Lossee et al showed that lambdoid synostosis takes on a trapezoid shape in a vertex view and a parallelogram shape from a posterior view.…”

“…Their distinction has historically been unclear, because similar clinical characteristics cause a true dilemma to arise. [1][2] Historically, Muakkassa et al described lambdoid craniosynostosis with the ear displaced anteroinferiorly. Muakkassa et al 7 published data on 64 cases of unilateral lambdoid synostosis and commented on the ear position (anterior in all cases); however, as Mulliken et al 8 points out, Muakkassa most likely over-reported cases of true lambdoid synostosis by including cases of posterior positional plagiocephaly in his cohort, and for that reason, his description of 64 cases of unilateral lambdoid synostosis has been excluded from this literature review.…”

“…[1][2][3] One of these features, the ipsilateral ear position, is a contentious diagnostic factor in lambdoid craniosynostosis. A classic article written by Huang et al, 1 the first report differentiating between the 2 conditions, remarked that the ear position in patients with lambdoid synostosis is posterior in comparison with the contralateral ear; however, more recently, at the Texas Children's Hospital, we have objectively noted that there are a number of patients with lambdoid synostosis, documented radiographically and intraoperatively, who clearly had anterior position of the ipsilateral ear.…”

Lambdoid Synostosis Versus Positional Posterior Plagiocephaly, a Comparison of Skull Base and Shape of Calvarium Using Computed Tomography Imaging

“…However, several distinguishing features have been previously presented. [1][2][3] According to these, a true ULC can be distinguished from PPP by the posterior bossing in the mastoid area in the synostotic side to the flat part of the lambdoid head. However, PPP is also noted to sometimes cause frontal bossing ipsilateral to the flat part of the head.…”

“…This condition is frequently confused with posterior positional plagiocephaly (PPP), which is a common craniofacial deformity caused by external forces on the skull during periods of craniofacial growth and maturation. [1][2][3][4] The clinical diagnostic features of ULC and PPP have considerable overlapping. Both skull types have calvarial deformities such as flattening of the occipital region.…”