Inclination of the Lip and Nose during Resting and Lip Protrusion in Children with Unilateral Cleft Lip

Abstract

Objective: To examine morphological changes of the lip and nose during resting and lip protrusion in patients with unilateral cleft lip.

Methods: A total of 41 patients with unilateral cleft lip who underwent primary lip repair were included in the study population. The distortion of the lip and nose was measured and evaluated using photographs of the preoperative and postoperative resting lips and the postoperative protruding lips.

Results: The position of the labial commissure on the affected side was cranially deviated before lip repair, and the deviation remained after surgery. The degree of cranial deviation was increased by lip protrusion. The position of the alar base on the affected side was caudally deviated before lip repair and improved after surgery; however, it was displaced cranially by lip protrusion. Horizontal displacement of the lip and nose was improved after surgery, and there was no change during lip protrusion.

Conclusions: The characteristic facial distortion in patients with unilateral cleft lip were confirmed. Patients with cleft lip had distortions in the labial commissure and the nose. One of the important future challenges in cleft lip treatment is to focus on changes caused by muscle movement and provide natural and symmetrical facial expressions.

Keywords: cleft lip; facial distortion; inclination of the lip and nose; lip protrusion; orbicularis oris muscle.

Figure 1.

Anthropometric measurements. The horizontal distance from the midline to the labial commissures (mid-ch, mid-ch’), the horizontal distance from the midline to the alae (mid-al, mid-al’), the angle between the inter-cheilion line (ch-ch’) and the horizontal axis (en-en), and the angle between the inter-subalare line (sbal-sbal’) and the horizontal axis were measured.

Figure 2.

Scatter diagrams for the lip width ratio. The relationship between the preoperative and postoperative values (a) and the relationship between resting and lip protrusion (b) are shown. The blue diagonal auxiliary line in each graph represents y = x.

Figure 3.

Scatter diagrams for the nasal width ratio. The relationship between the preoperative and postoperative values (c) and the relationship between resting and lip protrusion (d) are shown. The blue diagonal auxiliary line in each graph represents y = x.

Figure 4.

Scatter diagrams for the inclination of the lip. The relationship between the preoperative and postoperative values (e) and the relationship between resting and lip protrusion (f) are shown. The blue diagonal auxiliary line in each graph represents y = x.

Figure 5.

Scatter diagrams for the inclination of the nose. The relationship between the preoperative and postoperative values (g) and the relationship between resting and lip protrusion (h) are shown. The blue diagonal auxiliary line in each graph represents y = x.

Figure 6.

Representative case. Photographs of a patient with cCLA obtained preoperatively (left), 4 years postoperatively at rest (center), and 4 years postoperatively on lip protrusion (right). The inclination angles of the lip and nose were 1.60, 1.47, 3.37, and −5.25, 0.07, 2.15, respectively.

Figure 7.

Scatter diagrams for the inclination of the lip and nose in patients with incomplete cleft lip. The relationship between resting and lip protrusion are shown. The blue diagonal auxiliary line in each graph represents y = x.

Figure 8.

Schematic illustration of the hypothetical mechanism of the lip protrusion. (A): Resting position of the OOM and DSN. (B): Lip protrusion with the OOM and DSN function. (C): Lip protrusion without effective DSN function.