Determination of Mouth Width for Facial Reconstruction Based on Statistical Regression Model.

INTRODUCTION: It is important to generate predictable statistical models by increasing the number of variables on the human skeletal and soft tissue structures on the face to increase the accuracy of human facial reconstructions. The purpose of this study was to determine mouth width 3-dimensionally based on statistical regression model. MATERIAL AND METHODS: Cone-beam computed tomography scan data from 130 individuals were used to measure the horizontal and vertical dimensions of orbital and nasal structures and intercanine width. The correlation between these hard tissue variables and the mouth width was evaluated using the statistical regression model. RESULTS: Orbital width, nasal width, and intercanine width were found to be strong predictors of the mouth width determination and were used to generate the regression formulae to find the most approximate position of the mouth. CONCLUSION: These specific variables may contribute to improving the accuracy of mouth width determination for oral and maxillofacial reconstructions.

Nasal Morphology in a Young Adult Middle-Eastern Population: A Stereophotogrammetric Analysis.

AIM: This study aimed to describe gender-specific three-dimensional morphology of the soft-tissue nose in Lebanese young adults and to explore the associations between nasal morphology with age and body mass index (BMI). MATERIALS AND METHODS: Three-dimensional photographs were captured for 176 young healthy Lebanese adults (75 males and 101 females) aged 18.1-37.68 years. Linear and angular nasal measurements were computed and compared between genders, in addition to other established norms. Associations with age and BMI were also assessed. RESULTS: All linear measurements were greater in males than in females, and only the nasolabial angle was significantly larger in females by 2.97 degrees on average. Most of the measurements were found to be larger than the Caucasian norms. A few significant correlations were found between the measurements and age or BMI. CONCLUSION: This study is the first to present the sex-specific norms for nasal morphology in the Lebanese population and highlights the presence of gender dimorphism in the majority of measurements. Additional studies are needed to validate our data and expand the associations with age and BMI. CLINICAL SIGNIFICANCE: The data offered in this study could help enhance the accuracy of facial reconstructive surgery and aid in personalized treatment planning for both medical and cosmetic nasal interventions. How to cite this article: Saadeh M, Shamseddine L, Fayyad-Kazan H, et al. Nasal Morphology in a Young Adult Middle-Eastern Population: A Stereophotogrammetric Analysis. J Contemp Dent Pract 2024;25(3):199-206.

Male proboscis monkey cranionasal size and shape is associated with visual and acoustic signalling.

The large nose adorned by adult male proboscis monkeys is hypothesised to serve as an audiovisual signal of sexual selection. It serves as a visual signal of male quality and social status, and as an acoustic signal, through the expression of loud, low-formant nasalised calls in dense rainforests, where visibility is poor. However, it is unclear how the male proboscis monkey nasal complex, including the internal structure of the nose, plays a role in visual or acoustic signalling. Here, we use cranionasal data to assess whether large noses found in male proboscis monkeys serve visual and/or acoustic signalling functions. Our findings support a visual signalling function for male nasal enlargement through a relatively high degree of nasal aperture sexual size dimorphism, the craniofacial region to which nasal soft tissue attaches. We additionally find nasal aperture size increases beyond dental maturity among male proboscis monkeys, consistent with the visual signalling hypothesis. We show that the cranionasal region has an acoustic signalling role through pronounced nasal cavity sexual shape dimorphism, wherein male nasal cavity shape allows the expression of loud, low-formant nasalised calls. Our findings provide robust support for the male proboscis monkey nasal complex serving both visual and acoustic functions.

A nasal chemosensation-dependent critical window for somatosensory development.

Nasal chemosensation is considered the evolutionarily oldest mammalian sense and, together with somatosensation, is crucial for neonatal well-being before auditory and visual pathways start engaging the brain. Using anatomical and functional approaches in mice, we reveal that odor-driven activity propagates to a large part of the cortex during the first postnatal week and enhances whisker-evoked activation of primary whisker somatosensory cortex (wS1). This effect disappears in adult animals, in line with the loss of excitatory connectivity from olfactory cortex to wS1. By performing neonatal odor deprivation, followed by electrophysiological and behavioral work in adult animals, we identify a key transient regulation of nasal chemosensory information necessary for the development of wS1 sensory-driven dynamics and somatosensation. Our work uncovers a cross-modal critical window for nasal chemosensation-dependent somatosensory functional maturation.

Correlating Jaw Bone Growth and Nasal Morphology Among Adult Patients With Cleft Lip and Palate: A Retrospective Cephalometric Study.

This retrospective cross-sectional study reviewed adult patients with operated cleft lip and/or palate (CL/P) and normal control, and performed comprehensive craniofacial and nasal morphological analyses based on lateral cephalometric radiographs. Pearson or Spearman correlation coefficient assessed intraclass correlation. Seven hundred fifty-seven operated patients with CL/P, and 165 noncleft normal controls were enrolled. Among the normal and CL/P groups, S-N-A angle registered positive correlations with nasal base prominence (S-N'-Sn, degrees). Upper facial height (N-ANS, mm) had positive correlations with nasal dorsum length (N'-Prn, mm) and nasal bone length (N-Na, mm). Although in patients with bilateral cleft lip and palate, there were moderate negative correlations ( r =-0.541, P <0.05) with soft tissue facial profile angle (FH-N'Pog', degree) and nasolabial angle (Cm-Sn-ULA, degree). Correlation exists between the morphology of jaw bones and external nose among patients with CL/P. Maxillary sagittal insufficiency is associated with concave nasal profile, and maxilla height is associated with nasal length.

Reliability of a face scanner in measuring the vertical dimension of occlusion.

OBJECTIVE: This study evaluated the reliability of a face scanner in measuring the vertical dimension of occlusion (VDO). METHODS: Fully dentate volunteers (n = 20; mean-age = 30.0 ± 10.7 years) were recruited. Clinical facial measurements were obtained using a digital caliper and a face scanner (Obiscanner, Fifthingenium, Italy). The scans were imported into a mesh-processing software, and the distances were measured digitally. Measurements were obtained for each participant with the jaws positioned in maximal intercuspation (MI) and with increased vertical distances of 2, 4, and 6 mm. Vertical and horizontal measures were obtained using facial anatomical landmarks: Glabella (GL), Pronasale (PrN), Subnasale (SbN), inferior border of the right and left Alare, Labiale superius (Ls), right and left Cheilion (Ch), Soft Pogonion (SPg), right and left Tragus of the ear (Tr), for all selected vertical positions. Data analysis included intra-class correlation coefficient (ICC), pairwise comparison tests, Bland-Altman plots, and Passing-Bablok regression. RESULTS: 120 VDO measurements (clinical=60, digital=60) were recorded by two independent evaluators. Mean differences between digital and clinical measurements ranged from 0.054 ± 0.14 mm to 0.203 ± 0.13 mm. All parameters were strongly correlated (r > 0.93; p < 0.001). ICC estimates revealed excellent reliability, and the measuring procedure yielded the same results on repeated trials irrespective of the raters and measurement methods. Bland-Altman plots revealed a difference, between digital and clinical measurements, of 1.7 % for the vertical measurements. Regression analysis revealed no significant proportional difference between the two methods, so both can be used interchangeably. CONCLUSIONS: The findings of this study demonstrate that VDO can be measured accurately from face scans using 3D mesh-processing software and that even small changes in the VDO could be detected using the digital methods. CLINICAL SIGNIFICANCE: Findings provide evidence about the reliability of a digital method for jaw relation registrations and may be applied towards incorporating this method into clinical workflows for computer-aided-design/ computer-assisted-manufacturing (CAD-CAM) dentures.

Implications of Malignancy, Radiation, and Timing of Major Nasal Reconstruction.

Owing to the complex, multilayered anatomy of the nose in the central face, major nasal reconstruction can pose a significant challenge for reconstructive surgeons. It is the responsibility of reconstructive surgeons to have an understanding of the most common cutaneous malignancies and excisional techniques that may lead to complex nasal defects. The purpose of this article is to discuss these malignancies, excisional techniques, and impacts of radiation on tissue that has implications for reconstructive surgeons.

Accuracy of Dolphin Imaging software in predicting soft tissue changes of Class II Division 1 incisor relationship treated by all first premolar extraction compared with post-treatment lateral cephalogram.

BACKGROUND: To quantify the accuracy of Dolphin Imaging software in predicting soft tissue changes of Class II Division 1 incisor relationship treated by all first premolar extraction compared with actual changes. METHODS: Pretreatment and post-treatment lateral cephalograms of 30 young adult subjects (25 females and 5 males; age range of 16 to 21 years) were imported and traced in Dolphin Imaging software (version 11.95). Tracings of actual treatment results and the Dolphin predicted treatment outcome were superimposed to calculate the prediction errors. The mean difference for the Holdaway soft tissue analysis and at each landmark was measured in both the X and Y axes. Paired t test was used to compare the statistical differences in Holdaway soft tissue analysis parameters. RESULTS: There were significant differences between the predicted and actual values in three parameters of the Holdaway soft tissue analysis (P < 0.05). The overall accuracy of estimation was better in vertical direction than horizontal. Prediction of upper and lower lip landmarks was overestimated horizontally and underestimated vertically, whereas that belonging to chin was underestimated horizontally and overestimated vertically. Soft tissue nasion and soft tissue A-point were most accurately predicted, whereas the least accuracy was found in soft tissue chin region. CONCLUSIONS: Dolphin Imaging Software (version 11.95) can be accurate enough for use in patient communication and education but should be used with caution. It is most accurate in predicting soft tissue changes in the nasion and A-point regions, but least accurate in chin region.

Beyond skeletal studies: A computational analysis of nasal airway function in climate adaptation.

OBJECTIVES: Ecogeographic variation in human nasal anatomy has historically been analyzed on skeletal morphology and interpreted in the context of climatic adaptations to respiratory air-conditioning. Only a few studies have analyzed nasal soft tissue morphology, actively involved in air-conditioning physiology. MATERIALS AND METHODS: We used in vivo computer tomographic scans of (N = 146) adult individuals from Cambodia, Chile, Russia, and Spain. We conducted (N = 438) airflow simulations during inspiration using computational fluid dynamics to analyze the air-conditioning capacities of the nasal soft tissue in the inflow, functional, and outflow tract, under three different environmental conditions: cold-dry; hot-dry; and hot-humid. We performed statistical comparisons between populations and sexes. RESULTS: Subjects from hot-humid regions showed significantly lower air-conditioning capacities than subjects from colder regions in all the three conditions, specifically within the isthmus region in the inflow tract, and the anterior part of the internal functional tract. Posterior to the functional tract, no differences were detected. No differences between sexes were found in any of the tracts and under any of the conditions. DISCUSSION: Our statistical analyses support models of climatic adaptations of anterior nasal soft tissue morphology that fit with, and complement, previous research on dry skulls. However, our results challenge a morpho-functional model that attributes air-conditioning capacities exclusively to the functional tract located within the nasal cavity. Instead, our findings support studies that have suggested that both, the external nose and the intra-facial soft tissue airways contribute to efficiently warming and humidifying air during inspiration. This supports functional interpretations in modern midfacial variation and evolution.

Comparison of Functional and Cosmetic Outcomes Between Dorsal Preservation and Spreader Flap Rhinoplasty: A Randomized Trial.

BACKGROUND: Preservation rhinoplasty is a novel and increasingly utilized method in nasal plastic surgery. OBJECTIVES: The study aimed to compare the functional and aesthetic outcomes of dorsal preservation rhinoplasty, a new and interesting method, with conventional hump resection. METHODS: A total of 84 rhinoplasty applicants were randomly assigned to 2 groups. The first group underwent convention dorsal hump resection with spreader flap midvault reconstruction and the second group underwent dorsal preservation rhinoplasty with the modified subdorsal strip method. Aesthetic and functional outcomes, including residual hump, nasal width, projection, and rotation, were evaluated after 1 year with the Standardized Cosmesis and Health Nasal Outcomes Survey (SCHNOS), visual analog scale (VAS), and image analysis. RESULTS: Eighty-four patients with a mean age of 30.96 ± 6.75 years were recruited, of whom 15 (17.6%) were male. There were no significant differences in confounding variables between the 2 groups. There were no significant differences in residual hump (P = .11), nasal width (P = .37), projection (P = .70), rotation (P = .79), VAS (P = .81), or SCHNOS (P = .90) between the 2 groups. CONCLUSIONS: Dorsal preservation rhinoplasty with the modified subdorsal strip method may have comparable aesthetic and functional outcomes to spreader flaps midvault reconstruction.

Anatomical and Ultrasonographic Analyses of the Levator Labii Superioris Alaeque Nasi Muscle at the Level of the Nasal Ala / Análisis Anatómico y Ecográfico del Músculo Elevador Nasolabial a Nivel del Ala Nasal

SUMMARY: We aimed to determine the width of the levator labii superioris alaeque nasi muscle (LLSAN) at the level of the nasal ala through cadaveric dissections and ultrasonography (US), to provide essential anatomical information for use during both invasive and noninvasive procedures in the nasal ala region. The LLSAN was investigated in the 40 hemifaces of 20 Korean cadavers, comprising 10 males and 10 females with a mean age of 73.6 years. The LLSAN width of the 40 specimens at the level of the midpoint of the nasal ala was 5.02±2.35 mm (mean±standard deviation), and ranged from 1.45 mm to 10.11 mm. The LLSAN widths were 5.96±2.36 mm and 3.93±1.89 mm in males and females, respectively, with ranges of 2.40-10.11 mm and 1.45-6.96 mm, respectively. The LLSAN widths on the left and right sides were 4.77±2.72 mm and 5.26±1.99 mm, respectively. The proportions of the LLSAN fibers inserting into the nasal ala and upper lip were similar in 13 specimens (32.5 %), while more fibers inserted into the nasal ala in 11 specimens (27.5 %) and more fibers inserted fibers of the LLSAN into the upper lip in 16 specimens (40 %). When clinicians need to target or avoid the LLSAN, the present width and range data can be helpful for ensuring the efficacy and safely of both invasive and noninvasive procedures. In addition, the possibility of asymmetry in the width of the LLSAN in the nasal ala region should be confirmed by US before performing such procedures.

Nuestro objetivo fue determinar el ancho del músculo elevador nasolabial (MENL) a nivel del ala nasal mediante disecciones cadavéricas y ecografía, para proporcionar información anatómica esencial, para su uso durante procedimientos invasivos y no invasivos, en la región del ala nasal. El MENL se estudió en 40 hemicaras de 20 cadáveres coreanos (10 hombres y 10 mujeres) con una edad media de 73,6 años. El ancho de MENL de las 40 muestras a nivel del punto medio del ala nasal fue de 5,02 ± 2,35 mm (media ± desviación estándar) y osciló entre 1,45 mm y 10,11 mm. Los anchos de MENL fueron 5,96 ± 2,36 mm y 3,93 ± 1,89 mm en hombres y mujeres, respectivamente, con rangos de 2,40 a 10,11 mm y 1,45 a 6,96 mm, respec- tivamente. Los anchos de MENL en los lados izquierdo y derecho fueron 4,77 ± 2,72 mm y 5,26 ± 1,99 mm, respectivamente. Las proporciones de fibras de MENL que se insertaban en el ala nasal y en el labio superior fueron similares en 13 muestras (32,5 %), mientras que se insertaron más fibras en el ala nasal en 11 muestras (27,5 %) y además, se insertaron fibras de MENL en el labio superior en 16 ejemplares (40 %). Cuando los médicos necesitan apuntar o evitar el MENL, los datos actuales de ancho y rango pueden ser útiles para garantizar la eficacia y seguridad de los procedimientos, tanto invasivos como no invasivos. Además, la ecografía puede ser utilizada para confirmar una posible asimetría en el ancho del MENL en la región del ala nasal antes de realizar los procedimientos.

Overview of Nasal Airway and Nasal Breathing Evaluation.

Several methods are available for evaluating nasal breathing and nasal airflow, as this evaluation may be made from several different perspectives.Physiologic methods for nasal airway evaluation directly measure nasal airflow or nasal airway resistance, while anatomical methods measure nasal airway dimensions. Subjective methods evaluate nasal breathing through several validated patient-reported scales assessing nasal breathing. Computational fluid dynamics evaluates nasal airflow through the analysis of several physics' variables of the nasal airway.Being familiar to these methods is of utmost importance for the nasal surgeon to be able to understand data provided by the different methods and to be able to choose the combination of evaluation methods that will provide the information most relevant to each clinical situation.

Secondary Bilateral Cleft Rhinoplasty: Achieving an Aesthetic Result.

BACKGROUND: Secondary rhinoplasty in patients with bilateral cleft lip poses ongoing challenges and requires a reliable method for achieving optimal outcomes. OBJECTIVES: The purpose of this study was to establish a safe and effective method for secondary bilateral cleft rhinoplasty. METHODS: A consecutive series of 92 skeletally matured patients with bilateral cleft lip and nasal deformity were included. All had undergone secondary open rhinoplasty, performed by a single surgeon with a bilateral reverse-U flap and septal extension graft, between 2013 and 2021. Medical records of these 92 patients were reviewed to assess the clinical course. A 3-dimensional (3D) anthropometric analysis and panel assessment of 32 patients were performed to evaluate the aesthetic improvement, with an age-, sex-, and ethnicity-matched normal control group for comparisons. RESULTS: The methods showed statistically significant improvement in addressing a short columella (columellar height), short nasal bridge (nasal bridge length), de-projected nasal tip (nasal tip projection, nasal dorsum angle), poorly defined nasal tip (nasal tip angle, dome height, and panel assessment), and transversely oriented nostrils (columellar height, alar width, nostril type). Importantly, these improvements were accompanied by a low complication rate of 4%. However, upper lip deficiency over the upper lip angle and labial-columellar angle remained without significant improvement. CONCLUSIONS: In this study we described effective secondary rhinoplasty, which was composed of a bilateral reverse-U flap and septal extension graft, with acceptable outcome. The 3D anthropometric analysis and panel assessment clarified that our rhinoplasty procedure could bring the nasal morphology in these patients closer to the normal data.

Nasal Breathing Assessment Using Computational Fluid Dynamics: An Update from the Rhinologic Perspective.

An objective assessment of nasal breathing is currently insufficiently achievable. The application of computational fluid dynamics for this purpose is increasingly gaining attention. However, the suggested specific frameworks can differ considerably. To the best of our knowledge, there is not yet a widely accepted clinical usage of computational fluid dynamics. In this article, selected aspects are addressed that might be crucial for future development and possible implementation of computational fluid dynamics in rhinology.

Nasal Airway Evaluation.

The nose has several important functions including inspiration, humidification of air, and filtering of allergens. The nose also has a major role in facial harmony as the central focal point. Patients will present to the rhinoplasty surgeon in an effort to fix the inability to breathe through the nose or correct a perceived nasal deformity in the shape of the nose. Choosing the optimal techniques to effectively change the nose requires a thorough understanding of nasal anatomy and nasal mechanics. Ultimately, a complete nasal evaluation is essential in identifying what corresponds to a patient's complaints and how those issues can be addressed surgically or perhaps nonsurgically. When the nose is divided into subunits, and a systematic nasal analysis is performed, one can be confident that all components of the nasal skeleton have been assessed.

Regression analysis of nasal shape from juvenile to adult ages for forensic facial reconstruction.

The nose is a prominent feature for facial recognition and reconstruction. To investigate the relationship of the nasal shape with the piriform aperture in Korean adults and juveniles, we performed regression analysis. By regression analysis, prediction equations for nasal shape were obtained in relation to the shape of the piriform aperture considering sex and age groups. Three-dimensional skull and face models, rendered from computed tomography images, were assessed (331 males and 334 females). Juveniles (<20 years) were divided into three age groups according to the development of the dentition. Adults were divided into three age groups of two decades each, according to their age. To measure the nasal area, nine landmarks and nine measurements were chosen, while seven landmarks and five measurements were selected to measure the piriform aperture area. Four measurements were defined to explain the direct relationship between the nasal aperture and nasal shape. First, descriptive statistical analyses were performed according to sex and age groups. Subsequently, the correlation of nasal soft tissue measurements with piriform measurements was analyzed. Last, we performed a linear regression analysis of the measurements with higher correlations, considering sex and age groups as variables. Prediction equations were used to estimate the nasal bridge length, height, protrusion, and width. Equations considering sex and age groups showed better explanation ability. Measurements related to the height of the nasal bridge presented improvement. This study may assist in the more accurate approximation of nasal shape in facial reconstruction.

Longitudinal changes of the natural craniofacial and dentoalveolar complex in the fourth decade of life.

INTRODUCTION: This study aimed to longitudinally examine the changes in craniofacial and dentoalveolar regions during the third and fourth decades of life. METHODS: The data from this study constitute the cephalometric films and plaster models of 8 female and 8 male dental students or dentists. The mean chronological ages of the subjects at the first observation period was 22.09 years for females and 22.64 years for males. The material was collected over 3 intervals: 1985-1989, 1998-2000, and 2016-2017. The observation period was approximately 28 years. Acquired cephalometric recordings and dental models were assessed for subjects in their 20s (baseline), 30s, and 40s. Maxillary, mandibular, maxillomandibular, soft-tissue, and dentoalveolar cephalometric variables were measured with a cephalometric analysis software, and dental cast measurements were made with a digital caliper. Changes in the cephalometric films and dental casts were evaluated statistically. RESULTS: Statistical analysis showed that the length of the midfacial region increased with age. The height of the lower face increased significantly in females and the mandible can be seen mildly rotating to the posterior as it increased in length. The nose moved slightly forward and downward in males and females. Upper lip height was significantly increased in females; however, there was a significant reduction in upper lip thickness for males and females. Soft-tissue pogonion measurements showed a significant forward and downward chin movement in females. Overjet was significantly increased in females, whereas the mandibular arch length was significantly decreased for both sexes, although it was more prominent in females. There was a loss of space in the anterior segments of males and females, resulting in increased crowding. However, the loss of space was only significant in the mandible. CONCLUSIONS: We observed significant changes in skeletal, soft-tissue, and dentoalveolar variables of subjects in their third and fourth decades of life. The fact that many changes have occurred throughout this study demonstrates that the process of maturation and aging is ongoing.

Peak Nasal Inspiratory Flow (PNIF) for Nasal Breathing Evaluation.

Measuring nasal airflow and nasal breathing has been a major goal of rhinology. Many objective methods for measuring nasal airflow or nasal airway resistance or dimensions provide valuable data but are time-consuming and require expensive equipment and trained technicians, thus making these methods less practical for clinical practice. Peak nasal inspiratory flow (PNIF) measurement is fast, unexpensive, noninvasive, and able to provide an objective evaluation of nasal airflow in real-time. Unilateral PNIF measurements allow separated evaluation of each side of the nasal airway and may prove particularly useful when clinical assessment detects significant asymmetry between both nasal cavities.PNIF measurements are most useful for assessing changes in nasal airflow achieved by any form of therapy, including surgical treatment of the nasal airway. These measurements generally correlate with other objective methods for nasal airway evaluation, but not unequivocally with patient-reported evaluation of nasal breathing. Nevertheless, as low PNIF values prevent the sensation of a suitable nasal breathing, PNIF measurement may also prove useful to optimize the decision of how to best address patients with complaints of nasal airway obstruction.