Cheek mucosa territories perfused by perforators from the facial artery

Abstract

The cutaneous areas perfused by the cutaneous perforators of the facial artery have been well defined. However, the oral mucosal areas perfused by perforators of the facial artery have not been described. We studied 20 hemifaces from 10 cadavers. Perforators between the branching off sites of the labial arteries larger than 0.5 mm were selected and their diameters were measured; the distance between their exit point over the facial artery and the branching-off point from the superior labial artery was also measured. The selected perforators were injected with 1 ml of diluted ink. Both labial arteries were ligated to limit the study to the mucosal perforators from the facial artery. Seventy-four perforators from 20 hemifaces were studied; the mean diameter was 0.58 mm and the mean number per artery was 3.7. The total stained area, a triangle-shaped zone on the cheek, was determined. The more constant perforators larger than 0.5 mm were localized next to the branching-off site of the superior labial artery. With this information, flaps based on the mucosal perforators from the facial artery could be designed.

The use of oral mucosal flaps from the internal side of the cheek area to reconstruct oral defects has been well described by many authors. All these flaps are based on the facial artery and its branches. However, their vascular territories have not been established. Qassemyar et al. have described the cutaneous territories perfused by perforators from the facial artery. However, the facial artery perforators of the oral mucosa and the intraoral mucosal territories dependent on these perforators have not been described.

The objective of this study was to describe the oral mucosal perforasomes deriving from the facial artery, and also to determine their number, location, the mean perfused area, and their distribution.

Materials and methods

Twenty hemifaces from 10 fresh-frozen cadavers were used. The skin incisions followed a facelift pattern. Two incisions were added, the first from a ‘crow’s foot’ to the ipsilateral tragus, and the second from four finger widths below the horizontal branch of the jaw.

A supra-superficial musculoaponeurotic system (SMAS) dissection was performed and all superficial perforators that could be identified were ligated. The facial arteries were dissected from the base of the jaw up to the branching-off point from the upper labial artery. Oral mucosal perforators from the facial artery between the branching-off points of the superior and inferior labial arteries that were larger than 0.5 mm were selected ( Fig. 1 ).

Fig. 1
Dissection of the facial artery tree and identification of its branches; several inserts beneath the facial artery perforators are shown (light blue). Note the guide points on the gonion (G) and pogonion (P). The site corresponding to the oral commissure is shown with a green guide point.

The superior labial artery (SLA) and the inferior labial artery (ILA) were ligated after identification. Their branching-off points were determined. The posterior buccal branch of the facial artery was also ligated.

Descriptive anatomy

The length of the facial artery was measured from the lower edge of the jaw to the exit point of the SLA. The diameter of the facial artery was measured at the base of the jaw, the oral commissure, and the exit point of the SLA. The number of oral mucosal perforators was identified, as was their origin over the facial artery, taking the branching-off site of the SLA as a starting point.

Three landmark points were identified: the gonion, the pogonion, and the oral commissure. A line was traced between gonion and pogonion at the base of the jaw, and another parallel line starting from the oral commissure ( Fig. 1 ).

Perforators larger than 0.5 mm were selected and perfused with 1 ml of diluted ink. After each injection, the presence of colour in the oral mucosa was examined. If colouring was observed, the area was identified and measured using the software ImageJ version 1.45s ( Fig. 2 ).

Fig. 2
Areas of the cheek stained by the mucosal perforators from the facial artery. Note the four perforasomes: two anterior (black arrows) and two middle.

Statistical analysis

Stata software program was used for the statistical analysis (StataCorp LP, College Station, TX, USA). The Shapiro–Wilk test and the normal probability plot technique were performed to assess the normality of the variables. If the distribution of the variables was normal, the Pearson’s test was used. When distribution was non-normal, Spearman’s rank correlation coefficient was used to evaluate the results.

To determine the branching-off sites of the SLA and ILA, the guide points described previously were used. Means, standard deviations, and 95% confidence intervals (CI) were calculated. Tolerance limits (TL) were also obtained with 95% confidence, such that 95% of the general population are within the limits determined.

Results

The mean length of the facial artery from the base of the jaw to the exit point of the SLA was 62.70 ± 6.18 mm. The diameter of the facial artery was 2.74 ± 0.38 mm at the base of the jaw, 1.76 ± 0.27 mm at the oral commissure, and 1.28 ± 0.24 mm at the bifurcation of the SLA. The mean number of perforators larger than 0.5 mm was 3.70 ± 1.22. In six cases we found a fifth oral mucosal perforator, and in one case a sixth ( Table 1 ).

Table 1
General description of the facial artery.
Dissection number Sex FA diameter at the mandible (mm) FA diameter at the oral commissure (mm) FA diameter at the origin of the SLA (mm) Length of the FA from mandible to SLA (mm) Number of FAPM > 0.5 mm
1 M 2.30 1.90 0.90 62.30 2
2 M 2.98 1.50 1.25 52.20 2
3 M 3.65 1.71 1.37 59.05 2
4 M 2.74 1.91 0.98 57.93 5
5 M 2.44 1.61 1.25 63.98 6
6 M 2.55 1.90 1.11 64.58 5
7 M 2.51 1.62 1.23 63.30 5
8 M 2.71 1.68 0.96 64.96 3
9 F 2.86 1.64 1.20 66.22 3
10 F 2.23 1.76 1.10 61.71 3
11 F 2.24 1.56 0.97 65.23 5
12 F 2.51 1.59 1.28 74.77 3
13 F 2.73 2.03 1.35 60.72 3
14 F 2.50 1.85 1.70 58.98 4
15 M 3.06 1.71 1.67 65.19 4
16 M 2.62 1.63 1.59 74.87 4
17 F 3.51 2.68 1.58 67.43 4
18 F 2.67 1.87 1.49 64.27 5
19 F 2.96 1.61 1.27 49.56 4
20 F 3.03 1.42 1.39 56.82 2
Mean 2.74 1.76 1.28 62.70 3.70
SD 0.37 0.27 0.23 6.03 1.19
FA, facial artery; SLA, superior labial artery; FAPM, facial artery perforators of the oral mucosa; M, male; F, female; SD, standard deviation.

The SLA branched bilaterally from the facial artery in all cases. Taking the oral commissure as reference, the branching-off site of the SLA was identified 7.4 mm laterally and 5.1 mm above a line parallel to the lower edge of the jaw, between the gonion and pogonion. Using inferential statistics, we predicted the point of emergence of the upper labial artery within an area of 3 cm 2 in the general population ( Table 2 ).

Table 2
Statistical analysis of measurements relative to guide points. Inferential statistics to determine the branching-off site of the superior labial artery and the inferior labial artery in the general population from our sample, with a 95% confidence interval.
Artery Surface landmark Number of dissections Mean value (mm) SD (mm) 95% CI P < 0.05 95% TL P < 0.05
Superior labial artery Oral commissure Lateral 20 7.40 ±3.63 ±1.70 ±9.98
Oral commissure a Superior 20 5.12 ±2.76 ±1.29 ±7.60
Inferior labial artery Oral commissure Lateral 20 24.19 ±8.95 ±4.19 ±24.63
Base of jaw Superior 20 9.60 ±5.46 ±2.56 ±15.04
SD, standard deviation; CI, confidence interval; TL, tolerance limits.

a A line parallel to the base of the jaw was used.

The ILA was present bilaterally in eight of 10 heads. In the other two cases, the sub-labial artery was identified. The mean point of emergence of the ILA was 9.60 mm above the lower edge of the jaw, on a line from the gonion to the pogonion, and 24.19 mm lateral to the oral commissure. Statistical tolerance limits were 3 cm in the first case and 5 cm in the second ( Table 2 ).

Seventy-four perforators were measured. The mean diameter of the perforators at the branching-off site from the facial artery was 0.58 ± 0.19 mm. The 74 perforators were perfused and the mean area per perforator was 279.72 ± 156.24 mm 2 . The perforators were measured from the branching-off site from the SLA, and only those larger than 0.5 mm were selected ( Table 3 ).

Table 3
Analysis of mucosal perforators in order of appearance. Distribution of the 74 areas found in the 20 dissected hemifaces and anatomical localization: three anterior zones, two middle zones, and one posterior zone. a
FAPM position n FAPM origin over the course of FA (mm) Diameter (mm) Anatomical localization Coloured skin surface (mm 2 )
1st 20 4.51 ± 2.90 0.52 ± 0.20 45.0% Antero-superior 90% Anterior zones 379.23 ± 182.55
45.0% Antero-medial
10.0% Middle superior 10% Middle zone
2nd 20 10.34 ± 4.19 0.55 ± 0.21 35.0% Antero-medial 65% Anterior zones 305.83 ± 161.84
30.0% Antero-inferior
20.0% Middle superior 30% Middle zones
10.0% Middle inferior
5.0% Posterior
3rd 16 16.65 ± 4.01 0.52 ± 0.19 25.0% Antero-inferior 25% Anterior zones 187.02 ± 73.25
50.0% Middle superior 69% Middle zones
18.8% Middle inferior
6.3% Posterior 6% Posterior zone
4th 11 23.10 ± 5.23 0.49 ± 0.15 36.4% Middle superior 82% Middle zones 235.05 ± 99.77
45.5% Middle inferior
18.2% Posterior 18% Posterior zone
5th 6 31.74 ± 5.31 0.49 ± 0.13 50.0% Middle inferior 211.12 ± 105.58
50.0% Posterior
6th 1 40.92 100.0% Posterior 153.36
Total 74 0.53 ± 0.19 279.72 ± 156.24
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Jan 17, 2018 | Posted by in Oral and Maxillofacial Surgery | Comments Off on Cheek mucosa territories perfused by perforators from the facial artery
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