Robot-Assisted Nasal Reconstruction: A Cadaveric Study.

OBJECTIVE: Manual contouring of cartilage for nasal reconstruction is tedious and time-consuming. The use of a robot could improve the speed and precision of the contouring process. This cadaveric study evaluates the efficiency and accuracy of a robot methodology for contouring the lower lateral cartilage of the nasal tip. METHODS: An augmented robot with a spherical burring tool attached was utilized to carve 11 cadaveric rib cartilage specimens. In phase 1, the right lower lateral cartilage was harvested from a cadaveric specimen and used to define a carving path for each rib specimen. In phase 2, the cartilage remained in situ during the scanning and 3-dimensional modeling. The final carved specimens were compared with the preoperative plans through topographical accuracy analysis. The contouring times of the specimens were compared with 14 retrospectively reviewed cases (2017-2020) by an experienced surgeon. RESULTS: Phase 1 root mean square error of 0.40±0.15 mm and mean absolute deviation of 0.33±0.13 mm. Phase 2 root mean square error of 0.43 mm and mean absolute deviation of 0.28 mm. The average carving time for the robot specimens was 14±3 minutes and 16 minutes for Phase 1 and Phase 2, respectively. The average manual carving by an experienced surgeon was 22±4 minutes. CONCLUSIONS: Robot-assisted nasal reconstruction is very precise and more efficient than manual contouring. This technique represents an exciting and innovative alternative for complex nasal reconstruction.

How I do it: lateral canthal web revision-single Z-plasty technique.

BACKGROUND: Lateral canthal webbing is a known complication of blepharoplasty, which occurs when the lateral aspect of the upper blepharoplasty incision is taken below the equator of the lateral canthus. Removing excessive eyelid skin laterally can also result in a lateral canthal web. Currently, there is no standard approach for addressing this complication. METHODS: Retrospective review of single surgeon practice between 2011 and 2019. All patients underwent revision surgery using the proposed single Z-plasty technique. RESULTS: Twenty-three patients referred for lateral canthal web were included in the study. All patients had previous upper lid blepharoplasty, with the initial procedure occurring 8-63 months prior to the referral for revision. The majority of the blepharoplasties occurred in Ontario (n = 19), but some patients also underwent surgery in Alberta (n = 1), British Columbia (n = 1), and United States (n = 1). The initial surgeries were performed by a variety of specialities including plastic surgery (n = 16), otolaryngology (n = 4), ophthalmology (n = 2), and family medicine (n = 1). Following revision surgery using the single Z-plasty technique, all patients reported a subjective increase in functional and aesthetic satisfaction. No further revision surgery was required for any of these patients. CONCLUSION: The single Z-plasty technique is simple, robust, and could be easily incorporated into any cosmetic practice to address this complication of blepharoplasty.

Biomechanical Impact of a Zygoma Complex Fracture Using Human Cadaver.

ABSTRACT: Zygomaticomaxillary complex fractures are common in midface trauma, with treatment often involving repair using titanium mini plates. However, the need for plate fixation along the zygomaticomaxillary suture on the infraorbital rim remains controversial. This study utilized a previously reported bite force simulator to investigate craniofacial strain patterns following zygomaticomaxillary complex fracture repairs with and without plating of the infraorbital rim. Osteotomies were made to 6 fresh-frozen cadaveric heads to simulate 2 types of zygomatic complex fractures: a dipod fracture with osteotomies at the zygomaticofrontal and zygomaticomaxillary sutures, and a tripod fracture with an additional osteotomies at the zygomaticotemporal suture. Repairs with and without the use of a titanium mini plate across the infraorbital rim were compared in both dipod and tripod fractures. Physiologically proportional masticatory loads were applied using the bite force simulator by actuating intrinsic muscle lines of action. The outcome metric was facial bone strains measured using uniaxial strain gauges. Mixed-effects linear models did not find a significant main effect on the overall strain pattern with the use of an infraorbital rim plate in both dipod (P = 0.198) and tripod (P = 0.117) fracture repairs. However, statistically significant differences were found locally at the zygomatic buttress (P = 0.019) and the zygomatic arch (P = 0.027) on the fractured side in dipod fractures. This is the first known study that successfully utilized a mechanical simulator to reproduce physiological intrinsic masticatory loads in a fracture fixation study. This new technology opens avenues for future biomechanical investigations on maxillofacial fracture repairs and other surgical treatments.

Robot-Automated Cartilage Contouring for Complex Ear Reconstruction: A Cadaveric Study.

OBJECTIVES/HYPOTHESIS: Auricular reconstruction requiring manual contouring of costal cartilage is complex and time consuming, which could be facilitated by a robot in a fast and precise manner. This feasibility study evaluates the accuracy and speed of robotic contouring of cadaver costal cartilage. METHODS: An augmented robot with a spherical burr was used on cadaveric rib cartilage. Using a laser scanner, each rib section was converted to a three-dimensional model for preoperative planning. A model ear was also scanned to define a carving path for each piece of cartilage. After being contoured, each specimen was compared against the preoperative plan utilizing deviation maps to analyze topographic accuracy. Contouring times of the robot were compared with 13 retrospectively reviewed cases (2006-2017) by an experienced surgeon. RESULTS: Scanning the cartilage sections took 24.8 ± 6.8 seconds. Preoperative processing took an additional 29.9 ± 8.9 seconds for the preparation of the contouring path. Once the path was prepared, the robot contoured the specimens with a root mean square error of 0.54 mm and a mean absolute deviation of 0.40 mm. The average time to contour the specimens with the robot was 13 ± 2 minutes compared to 71 ± 6 minutes for the manual contouring in the reviewed cases. CONCLUSIONS: The accuracy of the robotic system was high, with submillimeter deviations from the preoperative plan. The robot required <20% of the contouring time compared to the experienced surgeon. This represents a fast and accurate alternative to hand-contouring costal cartilage grafts for auricular reconstruction. Laryngoscope, 131:1002-1007, 2021.

Near-infrared heating of skin to delineate non-melanoma skin cancer lesions: A pilot study.

BACKGROUND: Surgical excision is a mainstay of treatment for non-melanoma skin cancer (NMSC); improving margin delineation can reduce the need for further monitoring/treatment. The objective of this pilot study was to determine if near-infrared radiation (NIR) application to skin causes visible changes in normal and NMSC skin, to help delineate margins. MATERIALS/METHODS: Eleven biopsy-proven NMSC lesions were included. The skin was then heated under a 175W NIR heating bulb; margins were traced onto acetate film before and after heating. Lesions were then randomly assigned to excision based on pre- or post-heating margins. Composite images were generated by overlaying the heat and no-heat lesion contours. All specimens were sent for histopathology. RESULTS: The range of closest margins in the control group was 2.0-3.0 mm with a median of 2.0 mm; the range in the intervention group was 4.0-9.0 mm with a median of 5.0 mm. Composite images showed larger heat contours when the initial lesion was larger. There was a statistically significant difference between the two groups. Overall, NIR light caused visible hyperaemia to skin, and more intense erythema to malignant skin lesions. CONCLUSION: Near-infrared light may have use in an outpatient setting for skin cancer delineation, possibly reducing the rate of positive margins.

Does endoscopic sinus surgery alter the biomechanics of the orbit?

OBJECTIVE: The purpose of this study is to determine if removal of ethmoid cell septations as commonly performed in endoscopic sinus surgery leads to a change in orbital wall fracture patterns and the force required to create them. METHODS: Six fresh-frozen cadaveric heads were acquired and underwent endoscopic uncinectomy, maxillary antrostomy, and anterior and posterior ethmoidectomy on one, randomized, side. The contralateral sinuses were used as intra-specimen control. Hyaluronic acid gel globe injections were performed to simulate normal intra-ocular pressure. Post-op CT scans confirmed no orbital fractures or violation of the lamina papyracea prior to trauma testing. Orbital trauma was induced using a guided weight-drop technique. Both orbits were tested in random order, and sequentially higher drops were performed until both the test and control side demonstrated an orbital fracture on CT scan. RESULTS: In all six heads, the post-sinus surgery side incurred a medial orbital wall fracture, and no orbital floor fractures were identified. On the other hand, on the control side, all six heads incurred orbital floor fractures at drop heights equal to, or higher than, the surgical side. Fisher's exact test demonstrated a significant difference in fracture pattern (p <  0.001). CONCLUSIONS: To our knowledge, this is the first demonstration that the structures removed during sinus surgery may act as a buttress for the medial orbital wall. The anatomic changes of sinus surgery may alter the biomechanics of the orbit and affect the pattern of subsequent traumatic blowout fractures.

Bite Force Simulator: A Novel Technique to Simulate Craniofacial Strain In Vitro.

Existing in vitro simulators rely on external manipulation of the skull to replicate masticatory forces; however, external manipulations do not accurately represent internal loads as in physiological muscle forces.The purpose of the project is to develop an in vitro simulator that internally replicates the forces of mastication. The simulator has 3-dimensional-printed piston mounts that are reverse-engineered using a computed tomography scan of the specimen. The mounts are attached to the skull at muscle attachment sites using adhesive. The pneumatic pistons are sutured to muscle tendons; when the pistons are activated, they pull on the tendons which proportionally replicate muscle loads. The force output of the pistons can be individually modified by a custom software. Strain gauges are attached to craniofacial bones to measure deformation under replicated muscle loads. A 6 degrees-of freedom force sensor is placed intraorally to measure the generated bite force.The methodology was validated on 6 fresh-frozen cadaveric heads. Change in strain measurements was observed with change in simulated muscle loads. The simulator can validate computer simulation models and provide an experimental platform for craniofacial and dental implants. It sets the framework for a new, more physiologically consistent way of studying craniofacial stresses.

Nonmelanoma Skin Cancer.

This article reviews the most common nonmelanoma skin cancers affecting the head and neck region. Although the most common of these malignancies rarely result in mortality, local morbidity caused by the tumors and their extirpation cannot be underestimated. Complete tumor extirpation with pathologically confirmed negative margins is the gold standard. Regional and distant metastases are rare, but must be treated appropriately should they occur. Although reconstructive surgery can be life changing for the patients and rewarding for the clinicians, it behooves the treating surgeons to remain true to oncologic principles above all else.

The aesthetic unit principle of facial aging.

IMPORTANCE: In youth, facial aesthetic units flow together without perceptible division. The face appears as a single dynamic structure with a smooth contour and very little if any shadowing between different anatomical regions. As one ages, facial aesthetic units slowly become distinct. This process may be a consequence of differences in skin thickness, composition of subcutaneous tissue, contour of the facial skeleton, and location of facial ligaments. Although the impact of aesthetic unit separation is clinically apparent, its fundamental role in perceived facial aging has not yet been defined empirically. OBJECTIVES: To evaluate and define the effect of aesthetic unit separation on facial aging and to empirically validate the rationale for the blending of aesthetic units as a principle for facial rejuvenation. DESIGN, SETTING, AND PARTICIPANTS: We prepared the photographs of 7 women for experimental evaluation of the presence or absence of facial aesthetic unit separation. Photographic stimuli were then presented to 24 naive observers in a blinded paired comparison. For each stimulus pair, observers were asked to select the facial photograph that they considered to be more youthful in appearance. Each stimulus was compared with all others. MAIN OUTCOMES AND MEASURES: We calculated a preference score for the total number of times any photograph was chosen to be more youthful compared with all others. Paired t tests were used to compare the preference scores between the facial stimuli with and without aesthetic unit separation. RESULTS: We generated 4032 responses for analysis. Photographs without facial aesthetic unit separation were consistently judged to be more youthful than their aged original or modified counterparts, with mean preference scores of 0.66 and 0.33, respectively (P ≤ .047). When we selected the paired stimulus that directly compared one photograph with aesthetic unit separation with another with blended aesthetic units (2015 pairs), observers indicated that the photograph with the blended aesthetic unit was younger 95% of the time. Within-rater reliability was found to be very good (r = 0.88). CONCLUSIONS AND RELEVANCE: Our data support the hypothesis that facial aesthetic unit separation influences perceived facial youthfulness among photographs of women. The presence of facial aesthetic unit separation results in a less youthful appearance. Based on these empirical data, the concept of facial aesthetic unit separation appears to play a significant role in perceived facial aging. LEVEL OF EVIDENCE: NA.

The effectiveness of modified cottle maneuver in predicting outcomes in functional rhinoplasty.

Objective. To assess the outcomes of functional rhinoplasty for nasal valve incompetence and to evaluate an in-office test used to select appropriate surgical techniques. Methods. Patients with nasal obstruction due to nasal valve incompetence were enrolled. The modified Cottle maneuver was used to assess the internal and external nasal valves to help select the appropriate surgical method. The rhinoplasty outcomes evaluation (ROE) form and a 10-point visual analog scale (VAS) of nasal breathing were used to compare preoperative and postoperative symptoms. Results. Forty-nine patients underwent functional rhinoplasty evaluation. Of those, 35 isolated batten or spreader grafts were inserted without additional procedures. Overall mean ROE score increased significantly (P < 0.0001) from 41.9 ± 2.4 to 81.7 ± 2.5 after surgery. Subjective improvement in nasal breathing was also observed with the VAS (mean improvement of 4.5 (95% CI 3.8-5.2) from baseline (P = 0.000)). Spearman rank correlation between predicted outcomes using the modified Cottle maneuver and postoperative outcomes was strong for the internal nasal valve (Rho = 0.80; P = 0.0029) and moderate for the external nasal valve (Rho = 0.50; P = 0.013). Conclusion. Functional rhinoplasty improved subjective nasal airflow in our population. The modified Cottle maneuver was effective in predicting positive surgical outcomes.

Impact of nasal surgery on speech resonance.

OBJECTIVES: The nose and paranasal sinuses contribute to speech resonance and changes to these structures may alter speech nasality. This change may influence one's vocational and social functioning and quality of life. Our investigation explored objective and subjective changes in nasality following nasal surgery in a prospective and longitudinal fashion. METHODS: Recordings of sustained vowel and sentence stimuli and voice-related quality of life measurements were obtained preoperatively and at 2, 4, 8, and 24 weeks postoperatively from individuals undergoing nasal and/or sinus surgery. Objective measures of fundamental frequency, jitter, shimmer, and harmonic to noise ratio (HNR) were determined. Pre- and postoperative speech samples were assessed by 15 naïve listeners. RESULTS: In all, 15 subjects completed the study. Neither speakers nor listeners perceived a subjective change in nasality following surgery. No statistically significant change in microacoustic measures were identified. Although nasal sentences did not reveal differences for 3 microacoustic measures, a difference in HNR was identified. CONCLUSIONS: Patients undergoing nasal surgery did not exhibit subjective changes in resonance postoperatively. Aside from a difference in HNR for the nasal sentence, objective microacoustics remained unchanged. These results demonstrate the stability of oranasal resonance despite nasal surgery and provide valuable data for patient informed decision-making.

Implants in facial skeletal augmentation.

PURPOSE OF REVIEW: Alloplastic implants have demonstrated longstanding utility in the augmentation of the facial skeleton. Although their popularity may have waned in recent years, their established efficacy endures. This review summarizes the techniques, limitations, and complications associated with the use of facial implants. RECENT FINDINGS: Given the recognized utility of facial implants in the augmentation of the facial skeleton, they have received little attention in the recent literature. Contemporary reports have focused on the refinement of techniques--with renewed interest in the vertical transoral approach, and expanding the scope of facial implants--that is, the utility of facial implants as alternatives and/or adjuncts to orthognathic surgery. SUMMARY: Facial augmentation using alloplastic implants remains a tried, tested, and true means of correcting skeletal insufficiencies and abnormalities. Thus, what was once old will be new again, and a renaissance in the use of facial implants will undoubtedly occur.

Biomechanical properties of the facial retaining ligaments.

OBJECTIVE: Osteocutaneous facial retaining ligaments play an important role in the aging face. We sought to better characterize the biophysical properties of these ligaments and, in doing so, provide an empirical basis for the natural descent seen in facial aging. METHODS: Five fresh frozen cadaver heads yielding 10 hemifaces were dissected to expose the orbital, zygomatic, buccomaxillary, and mandibular osteocutaneous ligaments. Each ligament was assessed and subjected to biomechanical testing. The main outcome measures included ligament dimensions, stiffness, percentage of elongation, and force to initial and ultimate failure. RESULTS: Initial and ultimate failure testing revealed the zygomatic ligament to be strongest, followed by the orbital, mandibular, and maxillary ligaments. The zygomatic ligament was also stiffest, followed by the orbital, maxillary, and mandibular ligaments. The percentage of elongation acted as a surrogate marker of elasticity, with the greatest elasticity maintained by the mandibular ligament, followed by the orbital, zygomatic, and buccomaxillary ligaments. Ligament dimensions and biophysical properties did not vary relative to cadaveric hemiface, age, or sex. CONCLUSIONS: To our knowledge, this is the first investigation to quantify the biomechanical properties of the facial retaining ligaments. Inherent ligament properties seem to be related to the changes observed in facial aging, although further study is required.

Is three-dimensional videography the cutting edge of surgical skill acquisition?

The process of learning new surgical technical skills is vital to the career of a surgeon. The acquisition of these new skills is influenced greatly by visual-spatial ability (VSA) and may be difficult for some learners to rapidly assimilate. In many cases, the role of VSA on the acquisition of a novel technical skill has been explored; however, none have probed the impact of a three-dimensional (3D) video learning module on the acquisition of new surgical skills. The first aim of this study is to capture spatially complex surgical translational flaps using 3D videography and incorporate the footage into a self-contained e-learning module designed in line with the principles of cognitive load theory. The second aim is to assess the efficacy of 3D video as a medium to support the acquisition of complex surgical skills in novice surgeons as evaluated using a global ratings scale. It is hypothesized that the addition of depth in 3D viewing will augment the learner's innate visual spatial abilities, thereby enhancing skill acquisition compared to two-dimensional viewing of the same procedure. Despite growing literature suggesting that 3D correlates directly to enhanced skill acquisition, this study did not differentiate significant results contributing to increased surgical performance. This topic will continue to be explored using more sensitive scales of measurement and more complex "open procedures" capitalizing on the importance of depth perception in surgical manipulation. Anat Sci Educ. © 2012 American Association of Anatomists.

Carbon dioxide laser treatment for lentigo maligna: a retrospective review comparing 3 different treatment modalities.

OBJECTIVE: To assess outcomes in managing primary lentigo maligna through surgical excision, radiation therapy, and carbon dioxide laser ablation. METHODS: Retrospective case series review of all patients with primary lentigo maligna diagnosed and treated in London, Ontario, Canada, between July 2, 1991, and June 29, 2010. RESULTS: Seventy-five patients aged 39 to 93 years (mean age, 64.8 years) were included in the study; 73 patients chose treatment. Twenty-seven patients were treated with surgical excision, 31 patients with radiation therapy, and 15 patients with carbon dioxide laser ablation. The median follow-up times were 16.6 months for surgical excision, 46.3 months for radiation therapy, and 77.8 months for carbon dioxide laser ablation (P < .001). Recurrence rates by treatment modality were 4.2% (1 of 27) for surgical excision, 29.0% (9 of 31) for radiation therapy, and 6.7% (1 of 15) for carbon dioxide laser ablation. CONCLUSIONS: A trend toward lower recurrence rates with surgical excision and carbon dioxide laser ablation was identified, but the results were not statistically significant. Carbon dioxide laser ablation may have a role as an alternative treatment for lentigo maligna among patients in whom standard treatments, such as surgical excision and radiation therapy, are declined or carry significant morbidity.

Using photodynamic therapy as a neoadjuvant treatment in the surgical excision of nonmelanotic skin cancers: prospective study.

BACKGROUND: Topical photodynamic therapy (PDT) is a successful treatment for nonmelanotic skin cancers (NMSCs). Nevertheless, surgical excision continues to be the gold standard treatment. Cervicofacial excision often results in functional and aesthetic impairment. We hypothesize that topical PDT as a neoadjuvant therapy to surgical excision may reduce tumour size and subsequently decrease local morbidity. OBJECTIVE: To determine the utility of PDT in reducing the NMSC area for the purpose of surgical excision. METHOD: A prospective cohort study. RESULTS: Thirty-three basal cell carcinomas with a mean area of 523.11 ± 120.93 mm² and 26 squamous cell carcinomas with a mean area of 357.53 ± 61.96 mm² were included. Of these lesions, 22 demonstrated a complete curative response after an average of two PDT treatments, which were then confirmed with histologically negative biopsies. The remaining lesions demonstrated a partial response to topical PDT with a maximum reduction in lesion area following an average of three PDT treatments of at least 88% (p < .05). These lesions were then excised with clear histologic margins. Follow-up at 1 year for all lesions demonstrated no locoregional recurrence. CONCLUSIONS: This is the first study to investigate the efficacy of neoadjuvant topical PDT in the management of NMSC. The results suggest that for NMSC not demonstrating a complete curative response to PDT, neoadjuvant PDT can substantially reduce tumour burden, allowing for less morbid surgical excisions with histologically clear margins.

Neoadjuvant use of photodynamic therapy in Basal cell and squamous cell carcinomas of the face.

Background. This preliminary study sought to determine the success of photodynamic therapy (PDT) in reducing lesion size in an effort to assess the potential application of this treatment approach in a neoadjuvant role. Objectives. To quantify the effects of PDT on lesion area (mm(2)) for basal cell and squamous cell carcinomas of the face. Results. Eighteen participants (10 BCC lesions and 8 SCC lesions of the face) were assessed. Four lesions (all from the BCC group) showed a complete response to PDT. Of the remaining 14 lesions, 85.7% (n = 12) showed reductions in lesion area, while two lesions showed increase in lesion area. Proportional reductions for the 12 lesions that did not demonstrate complete response or an increase in area following-PDT were found to range from 13.2% to 85.1% (BCC) and 6.7% to 89.7% (SCC). Conclusions. PDT as a neoadjuvant treatment may provide a simple, efficient, and viable approach to reducing the area of malignant lesions of the face with the advantage of reduced cosmetic and aesthetic morbidities.