Objective:To investigate the morphological characteristics of skull base in children with hemifacial microsomia (HFM) by three-dimensional reconstruction and measurement of skull base.Methods:Three-dimensional spiral CT data of HFM children with unilateral involvement who had not received any treatment from the First Center of Maxillofacial Plastic Surgery, Plastic Surgery Hospital of the Chinese Academy of Medical Sciences from February 2010 to December 2020 were collected. The patients were divided into four groups according to the Pruzansky-Kaban classification standard: Ⅰ, Ⅱa, Ⅱb and Ⅲ. The three-dimensional reconstruction and measurement of the skull base were performed using Mimics 17.0 software. Linear measurements of the skull base included the distance from tuberculum sellae to optic canal (OT), foramen rotundum (FrT), foramen ovale (FT), internal acoustic meatus (IT), hypoglossal canal (HT), and the distance from anterior clinoid process to the lesser wing of the sphenoid bone (ClS) and the petrous ridge of the temporal bone (ClP). The measurement indexes of skull base angle included anterior cranial angle (ACA), middle cranial angle (MCA), posterior cranial angle (PCA), and petrous ridge angle (PRA). SPSS 26.0 software was used for statistical analysis of the measurement result. Paired t-test was used for comparison within each group, and one-way ANOVA was used for comparison between different types. P<0.05 was statistically significant. Results:A total of 40 children with HFM were collected, with 10 cases in each group. The result of skull base angle measurement showed that the MCA of the healthy side of typeⅠHFM was significantly larger than that of the affected side, and the MCA and PRA of the healthy side of type Ⅲ HFM were larger than those of the affected side ( P<0.05). There was no significant difference in the angle of skull base between the healthy side and the affected side of typeⅡa andⅡb HFM ( P>0.05). In terms of linear distance measurement of skull base, FrT and HT on the healthy side of typeⅠHFM were longer than those on the affected side; FrT, IT, HT and ClP on the healthy side of typeⅡa HFM were significantly longer than those on the affected side; IT, HT and ClP on the healthy side of typeⅡb HFM were longer than those on the affected side; and HT on the healthy side of type Ⅲ HFM was longer than those on the affected side ( P<0.05). The difference between FrT and ClP (affected / healthy) of four types of HFM was statistically significant ( P<0.05). Conclusions:The morphology of HFM is different between the affected side and the healthy side. As for the angle of skull base, MCA was obvious smaller in the affected side than that in the healthy side in the type Ⅰ and type Ⅲ HFM. As for the linear measurement, the distance from the hypoglossal canal to the tuberculum sellae on the affected side is shorter than that on the healthy side in each type HFM, indicating that the growth and development of the cranial base on the affected side is affected in a certain degree.

Objective:To investigate the morphological characteristics of skull base in children with hemifacial microsomia (HFM) by three-dimensional reconstruction and measurement of skull base.Methods:Three-dimensional spiral CT data of HFM children with unilateral involvement who had not received any treatment from the First Center of Maxillofacial Plastic Surgery, Plastic Surgery Hospital of the Chinese Academy of Medical Sciences from February 2010 to December 2020 were collected. The patients were divided into four groups according to the Pruzansky-Kaban classification standard: Ⅰ, Ⅱa, Ⅱb and Ⅲ. The three-dimensional reconstruction and measurement of the skull base were performed using Mimics 17.0 software. Linear measurements of the skull base included the distance from tuberculum sellae to optic canal (OT), foramen rotundum (FrT), foramen ovale (FT), internal acoustic meatus (IT), hypoglossal canal (HT), and the distance from anterior clinoid process to the lesser wing of the sphenoid bone (ClS) and the petrous ridge of the temporal bone (ClP). The measurement indexes of skull base angle included anterior cranial angle (ACA), middle cranial angle (MCA), posterior cranial angle (PCA), and petrous ridge angle (PRA). SPSS 26.0 software was used for statistical analysis of the measurement result. Paired t-test was used for comparison within each group, and one-way ANOVA was used for comparison between different types. P<0.05 was statistically significant. Results:A total of 40 children with HFM were collected, with 10 cases in each group. The result of skull base angle measurement showed that the MCA of the healthy side of typeⅠHFM was significantly larger than that of the affected side, and the MCA and PRA of the healthy side of type Ⅲ HFM were larger than those of the affected side ( P<0.05). There was no significant difference in the angle of skull base between the healthy side and the affected side of typeⅡa andⅡb HFM ( P>0.05). In terms of linear distance measurement of skull base, FrT and HT on the healthy side of typeⅠHFM were longer than those on the affected side; FrT, IT, HT and ClP on the healthy side of typeⅡa HFM were significantly longer than those on the affected side; IT, HT and ClP on the healthy side of typeⅡb HFM were longer than those on the affected side; and HT on the healthy side of type Ⅲ HFM was longer than those on the affected side ( P<0.05). The difference between FrT and ClP (affected / healthy) of four types of HFM was statistically significant ( P<0.05). Conclusions:The morphology of HFM is different between the affected side and the healthy side. As for the angle of skull base, MCA was obvious smaller in the affected side than that in the healthy side in the type Ⅰ and type Ⅲ HFM. As for the linear measurement, the distance from the hypoglossal canal to the tuberculum sellae on the affected side is shorter than that on the healthy side in each type HFM, indicating that the growth and development of the cranial base on the affected side is affected in a certain degree.