Facial soft tissue thickness measurement method and relationship with BMI, age and sex

Systematic review of soft-to-hard tissue ratios in orthognathic surgery: 3D analysis-update of scientific evidence

The aim of this research was to determine the soft-to-hard tissue ratio using three-dimensional (3D) analysis in different types of orthognathic surgery and to update the most recent scientific evidence provided in 2017. A systematic search covering the period January 2017-December 2023 was performed in the MEDLINE, Embase, LILACS, Scopus, and Science Direct databases to identify relevant studies. The methodological quality of the included studies was assessed using the method proposed by the Effective Public Health Practice Project. Of 897 articles identified in the database search, 10 were included in this review. These articles included analyses of points or anatomical areas of the face, and all of them used image superimposition for the analysis. The clinical analyses of the perinasal region, upper lip, and chin region produced ambiguous results. The bias in methods and variables, such as the types of surgery, patient variables, and differences in diagnosis may limit the use of the information obtained. There are no data that can be applied to daily clinical practice; the limited evidence that was previously published in 2017 remains.

Correlations of facial soft tissue thicknesses with craniometric dimensions improve craniofacial identification estimates: Fact or fiction?

Linear regression (LR) models that use cranial dimensions to estimate facial soft tissue thicknesses (FSTTs) have been posited by Simpson and Henneberg to assist craniofacial identification. For these regression equations to work well, the independent (craniometrics) and dependent (FSTTs) variables must be tightly correlated; however, such relationships have not been routinely demonstrated for adult humans. To examine the strength of these relationships further, this study employed magnetic resonance (MR) imaging to unambiguously measure cranial dimensions and FSTTs for 38 adult cadavers. This contrasts with prior published use of (a) spreading calipers to compress the face in an attempt to measure cranial dimensions through the soft tissues of the head and (b) needle puncture to measure the FSTT (a + b = legacy methods). To provide direct comparisons to prior work, this study also conducted legacy measurements for reproducibility tests. Previously published LR models were not supported by either the legacy or MR data. In the MR data, correlations between the cranial dimensions and FSTTs were generally weak with a mean absolute r = 0.13 and r range = -0.40 to 0.33. Compared to previously published arithmetic means, LR models did not improve FSTT estimates in the MR sample (SEE for LR = 5.5 mm; SEE for arithmetic mean = 5.2 mm). Using the latest MR imaging technologies, these results underscore prior warnings that cranial dimensions hold weak correlations with FSTTs and possess limited utility for improved FSTT estimation over and/or above arithmetic means.

Population comparison of facial soft tissue thickness

The thickness of the face's soft tissue has been widely measured through different populations around the world. In this study, we gathered and compared multiple measurements including our study group. We set the variables and included studies in which only females with normal values of BMI, age from 18 to 30years old were studied, and we included research with more than 10 study participants. We gathered 32 various studies and tested them with Kruskal-Wallis's test in RStudio. Statistical significance in tissue thickness was not confirmed when compared with the results of studies of different populations, which may indicate a greater importance in the bony mass in facial identification.

What comes first: teeth or face? Recommendations for an interdisciplinary collaboration between facial esthetic surgery and dentistry

OBJECTIVE

The aim of the present study was to provide recommendations in order to facilitate communication between dental professionals and surgeons who are collaborating in the field of dentofacial esthetics.

CLINICAL CONSIDERATIONS

Smile esthetics are beyond the scope, both of the surgeons who are collaborating with facial esthetics and of the dentists, as a wide range of treatment options from both sides is available. It can be difficult for the surgeon or the dentist that first comes in contact with the patient to conduct an individualized global treatment plan, in order to find out how the various phases of the treatment can be sequenced, as a workflow for an efficient interaction between facial surgery and dentistry still does not exist in the scientific literature.

CONCLUSIONS

Facial cosmetic procedures and dental treatment have to be planned as individual elements of the whole dentofacial esthetic rehabilitation. The treatment has to be initiated with the design of the smile and the intraoral mock-up, followed by the required surgical interventions, and to be finished with the delivery of the definitive dental restoration.

CLINICAL SIGNIFICANCE

Dentofacial esthetics require comprehensive communication between surgeons and dentists. Following the proposed recommendations, an individualized interdisciplinary treatment plan can be conducted, defining the role of each specialty.

Divergence between CBCT and Optical Scans for Soft Tissue Analysis and Cephalometry in Facial Imaging: A cross-sectional study on healthy adults

BACKGROUND

Facial soft tissue analysis is becoming increasingly emphasized in orthodontic diagnosis and treatment planning. While traditional cephalometry primarily focuses on hard tissues, recent non-invasive imaging techniques offer the potential to comprehensively evaluate three-dimensional (3D) facial soft tissues. The aim of the study was to establish the geometrical 3D and cephalometric divergence between Cone Beam Computed Tomography (CBCT) derived images and scanned soft tissues. Crucial for enhancing orthodontic diagnosis, minimizing patient exposure to ionizing radiation and providing facial cephalometric parameters.

MATERIAL AND METHODS

A cross-sectional study was conducted from January 2020 to May 2023. CBCT and 3D facial scans were obtained simultaneously using a specialized imaging system. Reproducible landmark points were selected for both cephalometric and soft tissue analysis. Angular and linear measurements were recorded, and correlations between CT and facial scans were statistically assessed.

RESULTS

Comparisons between 10 CBCT-derived and 10 facial scan-based soft tissue representations resulted into 1.8mm mean root median square (RMS). Angular measurements, such as ANB, right gonial angle, and left gonial angle, exhibited a 0.9° of difference with their respective soft tissue variables. In contrast, linear measurements of total anterior facial height showed a lower correlation coefficient, equal to 0.51. The correlation between soft tissues and underlying hard tissues was more pronounced for gonial angles.

CONCLUSION

Facial soft tissue analysis using either 3D facial scans or CBCT-derived offers similar results for orthodontic diagnosis and treatment planning. These findings support the use of non-invasive diagnostic tools in orthodontics, although further investigations are needed to comprehensively understand the complexity of hard and soft tissue relationships.