Three-Dimensional Analysis of the Ear Morphology

3D assessment of ear morphology

Introduction

Auricular reconstruction is a technically challenging and aesthetically demanding procedure as the ear has a complex anatomy. Anthropometry aids in achieving aesthetic ear reconstruction. We considered that implication of stereophotogrammetric technology will lead to a better understanding of human ear morphology.

Material and methods

A cross-sectional study was conducted in our institutional OPD in a tertiary health care centre in the Northern part of India.400 people were chosen based on selection criteria. facial scans were done for 3D pictures using Canfield VECTRA® H2 3D imaging device. Study variables were assessed after marking landmarks on the 3D-generated auricular image of an individual.

Discussion

This study consisted of 55.5% males and 44.5% females belonging to the age group of 5-25 years (30.3%), 26-40 years (38.8%) and>40 yr (31.0%). Out of 400 cases, the majority had; oval shaped auricle, normally rolled helix, square earlobe; knob shaped tragus. The attached type of earlobe attachment was more in the right auricle (37%) and the partial attachment ear lobe was more in the left side auricle (35.5%). Darwin's tubercle showed more proportion in the case of males. The mean length and width of the auricle & attachment length are higher in males compared to females. Ear Angulation is highest among females.

Conclusion

Assessment of ear morphology using technologically sound methods like stereophotogrammetry paves the way for a more quick, reliable and easy-to-use method for understanding ear morphology. Precise assessment of ear morphology using stereophotogrammetry helps in providing more cosmetic and acceptable ear restoration.

At-home sleep monitoring using generic ear-EEG

Introduction

A device comprising two generic earpieces with embedded dry electrodes for ear-centered electroencephalography (ear-EEG) was developed. The objective was to provide ear-EEG based sleep monitoring to a wide range of the population without tailoring the device to the individual.

Methods

To validate the device ten healthy subjects were recruited for a 12-night sleep study. The study was divided into two parts; part A comprised two nights with both ear-EEG and polysomnography (PSG), and part B comprised 10 nights using only ear-EEG. In addition to the electrophysiological measurements, subjects filled out a questionnaire after each night of sleep.

Results

The subjects reported that the ear-EEG system was easy to use, and that the comfort was better in part B. The performance of the system was validated by comparing automatic sleep scoring based on ear-EEG with PSG-based sleep scoring performed by a professional trained sleep scorer. Cohen's kappa was used to assess the agreement between the manual and automatic sleep scorings, and the study showed an average kappa value of 0.71. The majority of the 20 recordings from part A yielded a kappa value above 0.7. The study was compared to a companioned study conducted with individualized earpieces. To compare the sleep across the two studies and two parts, 7 different sleeps metrics were calculated based on the automatic sleep scorings. The ear-EEG nights were validated through linear mixed model analysis in which the effects of equipment (individualized vs. generic earpieces), part (PSG and ear-EEG vs. only ear-EEG) and subject were investigated. We found that the subject effect was significant for all computed sleep metrics. Furthermore, the equipment did not show any statistical significant effect on any of the sleep metrics.

Discussion

These results corroborate that generic ear-EEG is a promising alternative to the gold standard PSG for sleep stage monitoring. This will allow sleep stage monitoring to be performed in a less obtrusive way and over longer periods of time, thereby enabling diagnosis and treatment of diseases with associated sleep disorders.

Comparison of soft tissue simulations between two planning software programs for orthognathic surgery

The aim of this study was to compare the soft tissue predicative abilities of two established programs depending on the surgical technique and amount of displacement. On the basis of 50 computed tomography images, 11 orthognathic operations with differences in displacement distances and technique (maxillary advancement, MxA; maxillary impaction, MxI; mandibular setback, MnS; mandibular advancement, MnA bimaxillary displacement, MxA/MnS) as well as corresponding soft tissue predictions were simulated using the programs Dolphin (D) and ProPlan (PP). For all the soft tissue predictions by the two programs, eight linear and two angular measurements were performed and compared. The simulation of maxillary impaction showed a similar soft tissue behaviour between the two programs. However, differences or divergent behaviours were observed for other procedures. In the middle third of the face these significant differences concerned in particular the nasolabial angle (Ns-Sn-Ls)(5 mm-MA, D: 119.9 ± 8.6° vs. PP: 129.5 ± 8.4°; 7 mm-MnS: D: 128.5 ± 8.2° vs. PP: 129.6 ± 8.1°; 10 mm-MnA D: 126.0 ± 8.0° vs. PP: 124.9 ± 8.4°; 5 mm-MxA/4 mm-MnS, D: 120.2 ± 8.7° vs. PP: 129.9 ± 8.3°; all p < 0.001) and in the lower third the mentolabial angle (Pog´-B´-Li) (5 mm-MA, D: 133.2 ± 11.4° vs. PP: 126.8 ± 11.6°; 7 mm-MnS: D: 133.1 ± 11.3° vs. PP: 124.6 ± 11.9°; 10 mm-MnA D: 133.3 ± 11.5° vs. PP: 146.3 ± 11.1°; bignathic 5 mm-MxA/4 mm-MnS, D: 133.1 ± 11.4° vs. PP: 122.7 ± 11.9°; all p < 0.001) and the distance of the inferior lip to the aesthetic Line (E-Line-Li) (5 mm-MA, D: 3.7 ± 2.3 mm vs. PP: 2.8 ± 2.5 mm; 7 mm-MnS: D: 5.1 ± 3.0 mm vs. PP: 3.3 ± 2.3 mm; 10 mm-MnA D: 2.5 ± 1.6 mm vs. PP: 3.9 ± 2.8 mm; bignathic 5 mm-MxA/4 mm-MnS, D: 4.8 ± 3.0 mm vs. PP: 2.9 ± 2.0 mm; all p < 0.001). The soft tissue predictions by the tested programs differed in simulation outcome, which led to the different, even divergent, results. However, the significant differences are often below a clinically relevant level. Consequently, soft tissue prediction must be viewed critically, and its actual benefit must be clarified.

Evaluation of the External Ear and Head Anthropometric Dimensions Among Fars and Turk Workers for the Ergonomic Design of the Earmuffs

Background: Anthropometry plays an important role in the ergonomic design of hearing protection equipment and its compatibility with the dimensions of the external ear and head of workers. Few studies have been conducted on the dimensions of the external ears and heads of workers in Iran with different ethnicities. Objectives: This study aimed to collect the anthropometric dimensions of the external ear and head of workers of two prominent ethnicities of Iran for the ergonomic design of earmuffs. Methods: Following a cross-sectional design, this study was performed on 300 male workers (150 Turk and 150 Fars) aged 20 - 60 years. Anthropometric dimensions of the external ear and head were measured using a spreading caliper, camera, tripod, and tape measure. Photographs were analyzed using Digimizer V5.3.5 software, and data were analyzed using SPSS 21. Results: The mean age of Turk and Fars workers was 33.51 ± 5.41 and 33.95 ± 6.05 years, respectively. The ear shape was oval in more than half of the male workers of the two studied ethnicities. There was a positive correlation between anthropometric dimensions of head and ears in both ethnicities. The 95th percentile of the length and width of the pinna in Fars and Turk workers was larger than the average dimensions of inner ring earmuffs. Conclusions: Hearing protection devices available in the Iranian market should be examined to fit the ear dimensions of different Iranian ethnicities. External ear anthropometric data obtained from this study can be used to redesign the earmuffs in Fars and Turk male workers.

Evaluation of the Usability of a Low-Cost 3D Printer in a Tissue Engineering Approach for External Ear Reconstruction

The use of alloplastic materials instead of autologous cartilage grafts offers a new perspective in craniofacial reconstructive surgery. Particularly for regenerative approaches, customized implants enable the surgeon to restore the cartilaginous framework of the ear without donor site morbidity. However, high development and production costs of commercially available implants impede clinical translation. For this reason, the usability of a low-cost 3D printer (Ultimaker 2+) as an inhouse-production tool for cheap surgical implants was investigated. The open software architecture of the 3D printer was modified in order to enable printing of biocompatible and biologically degradable polycaprolactone (PCL). Firstly, the printing accuracy and limitations of a PCL implant were compared to reference materials acrylonitrile butadiene styrene (ABS) and polylactic acid (PLA). Then the self-made PCL-scaffold was seeded with adipose-tissue derived stem cells (ASCs), and biocompatibility was compared to a commercially available PCL-scaffold using a cell viability staining (FDA/PI) and a dsDNA quantification assay (PicoGreen). Secondly, porous and solid patient-customized ear constructs were manufactured from mirrored CT-imagining data using a computer-assisted design (CAD) and computer-assisted manufacturing (CAM) approach to evaluate printing accuracy and reproducibility. The results show that printing of a porous PCL scaffolds was possible, with an accuracy equivalent to the reference materials at an edge length of 10 mm and a pore size of 0.67 mm. Cell viability, adhesion, and proliferation of the ASCs were equivalent on self-made and the commercially available PCL-scaffolds. Patient-customized ear constructs could be produced well in solid form and with limited accuracy in porous form from all three thermoplastic materials. Printing dimensions and quality of the modified low-cost 3D printer are sufficient for selected tissue engineering applications, and the manufacturing of personalized ear models for surgical simulation at manufacturing costs of EUR 0.04 per cell culture scaffold and EUR 0.90 (0.56) per solid (porous) ear construct made from PCL. Therefore, in-house production of PCL-based tissue engineering scaffolds and surgical implants should be further investigated to facilitate the use of new materials and 3D printing in daily clinical routine.

Objective and Subjective Comparisons of Split Thickness Skin Graft and Full Thickness Skin Graft for Radial Forearm Flap Donor Sites Using a New Measuring Method

ABSTRACT

A split thickness skin graft (STSG) or a full thickness skin graft (FTSG) are commonly used for donor site closure after raising a radial forearm flap. The aesthetic outcome of the donor site is frequently not satisfying for the patient. This study evaluated the aesthetic outcome of the donor site of a radial forearm flap covered with an STSG or FTSG using an objective measurement method. The forearms of 30 patients (15 FTSG, 15 STSG) were scanned with an optical three-dimensional scanner. The surface of the forearm at the skin transplant was cut out and filled by an automatic hole-filling algorithm. The mean surface deviation between the original and the filled forearm was acquired. This method was validated with a control group of 15 volunteers. A questionnaire investigating aesthetical and healing satisfaction, postoperative pain and scarring was filled in by the patients. The mean surface difference in the STSG group was 0.9907 ± 0.3120 and 0.6177 ± 0.2245 mm in the FTSG group. The difference in the surface deviation between STSG and FTSG groups was significant (P = 0.0009). Correlations between the surface deviation and the subjective aesthetical satisfaction of the patient were not significant. In the questionnaires no significant differences between STSG and FTSG group were measured. Both FTSGs and STSGs resulted in good aesthetical outcomes after closure of a radial forearm flap donor site. Scanning the radial forearm flap donor site with an optical three-dimensional scanner supplied an objective, fast, and reliable measuring method of aesthetical outcomes.

Esthetic outcome after nasal reconstruction with paramedian forehead flap and bilobed flap

The incidence of skin cancer, which often affects the facial skin, has risen worldwide. After resecting such facial lesions, plastic reconstruction is necessary in most cases. The paramedian forehead flap (PFF) and the bilobed flap (BF) are commonly used for nasal reconstruction, but whether patients and physicians are satisfied with the esthetics is undetermined? In this study, scar questionnaires (Manchester Scar Scale, Vancouver Scar Scale, and Patient and Observer Scar Assessment Scale) and optical three-dimensional (3D) imaging were used for subjective and objective evaluation of esthetical outcomes after plastic reconstruction of the nose in 30 patients. The distances between landmarks and changes in volume between the treated and both the mirrored, healthy side of the face as well as an untreated, matched control group were measured using the optical (3D) scans. The questionnaires ascertained whether the patient was content with the esthetical outcome of both flaps. In the opinion of the observer, the esthetical outcome of both flaps was sufficient; only a few of the measured distances differed significantly between the patients and the control group. However, the measured volume differences of the donor site of the flap differed significantly between the PFF group and the control group (p = 0.0078). The BF was used for smaller defects, while the PFF was used for major defects. Besides a greater donor-side morbidity for the PFF, both flaps led to esthetically sufficient results and could be used for the reconstruction of the nose depending on the defect size and localization.

Morphological changes of the human face after massive weight-loss due to bariatric surgery

The aim of this study was to evaluate the morphological changes in the face of obese patients during massive weight loss using a more reliable method than two dimensional photographs or tape measures. The faces of 23 patients were recorded prior to and six months after bariatric surgery. Distances between important anatomical landmarks of the face were calculated and the volume of the neck was compared. The distance between the Tragion and Subnasale (132.7 ± 6.804 mm to 131.5 ± 6.866 mm; p = 0.0003), and the distance between Tragion and Stomion became significantly longer 136.0 ± 8.016 mm to 134.3 ± 7.698 mm; p = 0.0031), while distances between the Tragion and Pogonion (150.2 ± 8.216 mm to 148.3 ± 8.383 mm; p < 0.0001), Tragion and Menton (152.3 ± 9.037 mm to 148.9 ± 9.623 mm; p < 0.0001), and Tragion and tip of the nose (144.9 ± 7.273 mm to 144.0 ± 7.416 mm; p = 0.0023) were significantly reduced. The mean volume loss of the neck was 75.218 ± 40.197 ml. No significant correlation was found between total weight loss and cervical volume loss (r = 0.3447; p = 0.1072). The morphological changes of the face after massive weight loss vary in different areas of the face. Patients and their attending physicians must be aware of the face's morphology change after massive weight loss in an extent that does not correlate with the total weight loss of the patient.

Effect of the aging process on columella-labial, naso-mental and facial angles and how to apply it in clinical practice

BACKGROUD

Aging is the result of the interplay of changes occurring in the facial skeleton, ligaments, muscles, adipose tissue, and skin (1), and these changes befall each mentioned structure at a different pace, start in each individual at a different age, and differ between ethnic background. (4) It changes directly the measurements of the face angles, making the face more concave and flattened aspect, while the young face presents a more convex and rounded aspect. Female skulls had an increase in all transverse facial widths and depth of the middle face with increasing age. Therefore, aging is consequence of progressive changes through intrinsic and extrinsic factors (5) and different methods can be used to assess and diagnose these changes.

AIMS

The aim of the study is to evaluate facial angles and their aging changes.

METHODS

A retrospective study was performed with a total of 1213 Caucasian female patients in the author's private clinic. The angles evaluate age-related changes were analyzed: facial, naso-mental, and columella-labial angle. Photograph analysis program Vectra 3D (Canfield) was used to perform the anthropometric assessment of the angles, and after data collection, the analysis was performed statistics.

RESULTS AND CONCLUSION

We could conclude angles analyzed change with age, while two angles increase (naso-mental and facial angle), the other decreases (columella-labial angle). The study reinforces the principle of an objective clinical anthropometric assessment of facial angles as a relevant guide for a more appropriate treatment plan for the doctor to perform aesthetic procedures in order to restore a youthful face.

Three-dimensional evaluation of important surgical landmarks of the face during aging

BACKGROUND

One surgical objective is creating an aesthetically satisfying outcome. The morbidity increases with age. Standard values for areas of the face, which are frequently surgically treated, are needed for the surgeon.

METHODS

240 Caucasians aged 21-65 were divided into six subgroups by gender and age. They were scanned by a three-dimensional (3D) scanner. Distances and angles in faces between landmarks were evaluated.

RESULTS

During aging, the relation of the eye's width to the eye's height became significantly smaller (M: p=0.001, F: p≤0.0001). The outer contour of the nose became significantly sharper with increasing age (M: p=0.001, F: p=0.0021). Seen from caudal, the nose formed an isosceles triangle with the base between the left and right alar curvature and the base had an average length of 31.35mm±2.97mm. The leg of this triangle had an average length of 33.67mm±2.09mm. The nose got longer and wider during aging; the age-dependent changes between the different groups of males (p≤0.0001) and the difference between females and males were significant (p≤0.0001). The thickness of the nasal wings remained the same size during a lifetime. Females had significantly greater heights for both lips (p≤0.0001, p=0.027). In males and females, the heights decreased with increasing age.

CONCLUSION

This study provided a database of measurements of parts of the face, especially those parts that can underlie various surgical treatments.

Correlation Between Mandible and External Ear in Patients with Treacher-Collins Syndrome

BACKGROUND

Patients with Treacher-Collins syndrome (TCS) are frequently affected by congenital ear deformities. The external ear in patients with TCS tends to have both abnormal morphology and reduced overall volume. Previous studies considered a correlation exists between TCS mandibular skeletal features and external ear volume. The purpose of this study was to assess the external ear volume in patients with TCS 3-dimensionally. Furthermore, this study evaluated the relationship between mandibular morphology, external ear profile, and external ear volume.

METHODS

A total of 36 nonoperated patients with TCS were compared to 39 age- and gender-matched normal controls. Morphologic variables of the mandible and the external ear were compared between TCS group and controls by 3-dimensional cephalometrics. The external ear volume and morphologic variables were analyzed with independent sample T-tests and Pearson correlation coefficient analyses (level of evidence: level III).

RESULTS

The external ear volume was reduced by approximately 50% in patients with TCS compared to controls (P < 0.001). External ear length and width were positively correlated with external ear volume (length: r = 0.809, P < 0.001 on left and r = 0.732, P < 0.001 on right; width: r = 0.518, P = 0.001 on left and r = 0.447, P < 0.010 on right). A negative correlation of right ear inclination angle and external ear volume was shown in patients with TCS (r = -0.396, P = 0.027). However, no correlation was shown for the mandibular anatomic variables.

CONCLUSIONS

Three-dimensional analysis confirmed that external ear volume is significantly reduced in patients with TCS. The external ear dimensions and orientation correlated significantly with ear volume. There was no intrinsic association between the severity of mandibular deformity and external ear volume.