Fogorvosi szemle, 2021 (114. évfolyam, 1-4. szám)

2021-12-01 / 4. szám

FOGORVOSI SZEMLE

114. évf. 4. sz. 2021.

n

177

the analysis of the facial changes, we conducted the deviation analysis of the facial meshes in seven morphological regions across the whole face rather than focusing only on certain linear and angular measurements.

Although the high positive and negative deviation limits were observed in the total face region in our study, the mean deviation of all landmarks forming the region didn’t exceed 0.52 ± 0.25 mm. This small magnitude can be explained by the multidirectional soft tissue changes in the facial parts forming the overall facial envelope.

We found facial soft tissue changes in both the upper face and lower face regions with a mean of 0.77 ± 0.51 and 0.67 ± 0.38 mm respectively, while the mean deviation at the nasal region was 1.03 ± 0.14 mm. Previous studies of maxillary advancement and mandibular setback reported more soft-tissue movement in the central parts than in the lateral parts [25

]. While Gjorup et al found that no changes occurred in the cheeks, they took into consideration that the influence of the muscles and soft tissue tension decreased as the distance from the area where the hard tissue changes increased [20

].

The highest magnitude of the soft tissue changes was found in the upper lip region with a mean deviation of 3.25 ± 0.19 mm and high positive and negative deviation peaks of 5.71 ± 0.11 mm and –2.67 ± 0.27 mm respectively.

In regard to the lower lip and chin regions, we noticed soft tissue decrease of –1.21 ± 0.37 mm and –1.66 ± 0.09 mm respectively. Baik et al.

suggested that the semi-circular shapes of the maxilla and the mandible correspond to fewer changes in the sub-commissural region (a lateral part) than in the labio-mental or chin regions (a central part) [7

].

To provide a better overview of the facial changes, we calculated the deviation using designated landmarks of the face. The magnitude of deviation at the level of bilateral Alar points (1.26mm and 0.85 mm for the right and the left respectively) emphasizes lateral and anterior movements mentioned above. A similar movement can be anticipated at the level of bilateral Alar curvature landmarks (1.36, 1.14 mm), indicating soft tissue changes in the nasal region along with the deviation noticed at the level of pronasal and subnasal (1.93mm and 3.03 mm) regions respectively.

Similar results were found in the study of Çoban et al

, which reported lateral movement of bilateral alar and alar curvature landmarks in addition to the upward and forward movements of alar and alar curvature, subnasale, labiale superior, sublabiale, and pogonion, which concurs with our findings [14

].

In the upper lip area, a positive deviation of 3.12 mm was found at the level of Labiale superius point, which is indicative of anterior moment following a bimaxillary surgery. Furthermore, following bimaxillary osteotomies, deviations of –3, –2.5, –1.3 mm at the level of Labiale inferius, Soft tissue pogonion, and Soft tissue menton respectively were reported in our study, which may indicate a posterior movement of the soft tissue in both the lower lip and the chin regions and confirm our previous results in the linear and angular measurements.

Even though small sample size being is one of the limitations of our study, it has delivered relevant and valuable information regarding three-dimensional soft tissue changes of the face. In order to further advance the clinical research and the analysis, it may be beneficial to be repeat the study with a larger sample size and to consider the gender-related effects.

Conclusion

In our present comprehensive 3D evaluation, we succeeded to quantify and visualize the post-operative soft tissue changes in the 6th month of post bimaxillary surgery. Even in the presence of limitations of a small sample size, we concluded that, compared to the other facial structures, the middle third of the face, especially the nose and the upper lip, will be affected by the bimaxillary surgery. These expected changed should be taken into account when planning the treatment, and the patients must be informed accordingly. Further investigations with a larger sample size and appropriate controls will be necessary for a more precise evaluation of the soft tissue responses following a bimaxillary surgery.

References

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