The aponeurotic tension model of craniofacial growth in man

Anatomic development of the upper airway during the first five years of life: A three-dimensional imaging study

Purpose

Normative data on the growth and development of the upper airway across the sexes is needed for the diagnosis and treatment of congenital and acquired respiratory anomalies and to gain insight on developmental changes in speech acoustics and disorders with craniofacial anomalies.

Methods

The growth of the upper airway in children ages birth to 5 years, as compared to adults, was quantified using an imaging database with computed tomography studies from typically developing individuals. Methodological criteria for scan inclusion and airway measurements included: head position, histogram-based airway segmentation, anatomic landmark placement, and development of a semi-automatic centerline for data extraction. A comprehensive set of 2D and 3D supra- and sub-glottal measurements from the choanae to tracheal opening were obtained including: naso-oro-laryngo-pharynx subregion volume and length, each subregion’s superior and inferior cross-sectional-area, and antero-posterior and transverse/width distances.

Results

Growth of the upper airway during the first 5 years of life was more pronounced in the vertical and transverse/lateral dimensions than in the antero-posterior dimension. By age 5 years, females have larger pharyngeal measurement than males. Prepubertal sex-differences were identified in the subglottal region.

Conclusions

Our findings demonstrate the importance of studying the growth of the upper airway in 3D. As the lumen length increases, its shape changes, becoming increasingly elliptical during the first 5 years of life. This study also emphasizes the importance of methodological considerations for both image acquisition and data extraction, as well as the use of consistent anatomic structures in defining pharyngeal regions.

Combined Symphyseal and Condylar Fractures: Considerations for Treatment in Growing Pediatric Patients

BACKGROUND

Combined symphyseal-condylar mandible fractures are relatively common but difficult to manage in children. This study investigated the cause and management of symphyseal-condylar fractures in pediatric patients.

METHODS

This study presents a retrospective review and expert opinion of pediatric symphyseal-condylar mandibular fracture management at the authors' institution between 1990 and 2019. National data from the Healthcare Cost and Utilization Project Kids' Inpatient Database (2000 to 2016) were used to determine whether institutional data had national applicability.

RESULTS

Twenty-one patients at the authors' institution met inclusion criteria. Of these patients, 26.7 percent of deciduous dentition patients underwent open reduction and internal fixation, 40 percent underwent closed treatment (maxillomandibular fixation), and 33.3 percent received a soft diet. All mixed dentition patients underwent open reduction and internal fixation or closed treatment; all permanent dentition patients underwent open reduction and internal fixation. The national database (n = 1708) demonstrated similar treatment patterns: most permanent dentition patients (88.7 percent) underwent open reduction and internal fixation, most mixed dentition patients (79.2 percent) underwent closed treatment, and among deciduous dentition patients, 53.5 percent patients received a soft diet; 38 percent received closed treatment. In this study, the overall posttreatment complication rate was 62.5 percent among open reduction and internal fixation patients, 14.3 percent among closed treatment patients, and 16.7 percent among patients treated with a soft diet.

CONCLUSIONS

Symphyseal-condylar mandibular fractures were associated with substantial morbidity in children. The authors created a treatment algorithm to maximize outcomes in children who suffer from this challenging fracture pattern.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Growth and sexual dimorphism of the hyoid bone and its relationship to the mandible from birth to 19 years: A three-dimensional computed tomography study

The hyoid bone and the hyomandibular complex subserve the functions of respiration, deglutition, and speech. This study quantified the growth of the hyoid bone and the hyomandibular relationships in males and females from birth to 19 years. Using 97 computed tomography (CT) scans, from a previous study (Kelly et al., 2017) on mandibular growth from 49 individuals (16 with longitudinal scans), landmarks were placed on 3D CT models and used to calculate four distance, and three angular measurements. A general increase in growth trend was observed in hyoid bone linear measurements-length, width, and depth-as well as relational mandible-to-hyoid distance, throughout the developmental ages examined in both males and females, with most variables having larger measurements for females up to age 10 years. A general decrease in all three angular measurements was observed in both males and females up to approximately age 12 years, at which time male angular measurements gradually increased with significant sexual dimorphism emerging after age 15 years. As expected, postpubertal males had greater hyoid angle than females; they also had greater hyoid angle of inclination than mandible body inclination (with inclination relative to the anterior-posterior nasal plane), likely related to hyo-laryngeal descent. This study contributes to normative data on hyoid bone and hyomandibular relational growth in typically developing individuals and provides a baseline against which structural and functional influences on anatomic growth may be examined by clinical disciplines that address the aerodigestive and speech functions, as well as the fields of anatomy, forensics, and anthropology.

An Insight into the Role of the Maxillary Labial Frenum in the Growth of the Maxilla: A Systematic Review

Background: The review attempts to provide synthesis of published studies evaluating the influence of an aberrant frenum attached close to the gingival margin or with inadequate width of attached gingiva on the growth of the maxilla.

Methodology: This review was reported using the PRISMA checklist as a template. PubMed, EBSCO and Google scholar were searched for in earlier publications up to January 2019. In addition, reference lists of the included studies were hand searched. The eligibility criteria were listed out based on Population, Intervention, Comparison, Outcome, Study type (PICOS) concept.

Results: A total of 148 articles were found by database search strategies and 27 additional studies by hand search. Finally three cross sectional and one longitudinal study were selected based on the eligibility criteria. A meta-analysis was not justified. Risk of bias was assessed using AXIS tool for cross sectional studies and Newcastle-Ottawa scale for longitudinal study. Common weaknesses of the studies were failure to justify or calculate the sample size and insufficient statistical reporting.

Conclusion: This review reveals that there is a need for methodologically standardized studies that will throw light on to the physiological importance of labial frenum in the growth of the nasomaxillary complex.

Prevalence of variations in morphology and attachment of maxillary labial frenum in various skeletal patterns - A cross-sectional study

Background

Maxillary labial frenum is a dynamic structure with a diverse morphology. Although an abnormal labial frenum is associated with syndromic and nonsyndromic conditions, it is often been neglected during the routine intraoral examination. The significance of various types of frenum (normal to abnormal), based on the attachment site and morphology in different skeletal patterns, has not been studied yet.

Materials and Methods

A cross-sectional study was conducted in a clinical setting on 150 participants (50 each in Class I, Class II, and Class III skeletal pattern) within the age group of 13-30 years. Frenum was examined by direct visual method and intraoral photographs were taken for all the participants.

Results

Chi-square and Fisher's exact tests were used. No gender-wise differences were found among the various frenum typologies. Mucosal type was the most prevalent in Class I and II and gingival type in Class III. Simple frenum was the common type in all the three groups. However, abnormal frenum categories based on its location and morphology were more in class III and found to be statistically significant. Papillary and papillary penetrating types are significantly associated with skeletal class III pattern and midline diastema (P < 0.05).

Conclusion

The prevalence of papillary and papillary penetrating types of frenum are significantly more in Class III skeletal pattern. A labial frenum that is attached close to the gingival margin could be an etiological factor in midline diastema, mucogingival problems, and affect the growth of the alveolar process. Hence, an early diagnosis of abnormal frenum prevents the emergence of periodontal as well as orthodontic problems.

Involvement of Mechanical Stress in Androgenetic Alopecia

Context:

Androgenetic alopecia (AGA) is a frequent disorder characterized by progressive hair miniaturization in a very similar pattern among all affected men. The pathogenesis is related to androgen-inducible overexpression of transforming growth factor β-1 from balding dermal papilla cells, which is involved in epithelial inhibition and perifollicular fibrosis. Recent research shows that hair follicle androgen sensitivity is regulated by Hic-5, an androgen receptor co-activator which may be activated by the mechanical stimulation. Moreover, the dermis of scalp susceptible to be affected by AGA is firmly bounded to the galea aponeurotica, so the physical force exerted by the occipitofrontalis muscle is transmitted to the scalp skin.

Aims:

To know whether mechanical stress supported by hair follicles is involved in AGA phenomenon.

Materials and Methods:

It is performed with a finite element analysis of a galea model and a schematic representation of AGA progression according to Hamilton–Norwood scale in order to establish the correlation between elastic deformation in scalp and clinical progression of male pattern baldness.

Results:

The result was a highly significant correlation (r: −0.885, P < 0.001) that clearly identifies a mechanical factor in AGA development.

Conclusions:

All these data suggest that mechanical stress determines AGA patterning and a stretch-induced and androgen-mediated mechanotransduction in dermal papilla cells could be the primary mechanism in AGA pathogenesis.

Clinical and symptomatological reflections: the fascial system

Every body structure is wrapped in connective tissue, or fascia, creating a structural continuity that gives form and function to every tissue and organ. Currently, there is still little information on the functions and interactions between the fascial continuum and the body system; unfortunately, in medical literature there are few texts explaining how fascial stasis or altered movement of the various connective layers can generate a clinical problem. Certainly, the fascia plays a significant role in conveying mechanical tension, in order to control an inflammatory environment. The fascial continuum is essential for transmitting muscle force, for correct motor coordination, and for preserving the organs in their site; the fascia is a vital instrument that enables the individual to communicate and live independently. This article considers what the literature offers on symptoms related to the fascial system, trying to connect the existing information on the continuity of the connective tissue and symptoms that are not always clearly defined. In our opinion, knowing and understanding this complex system of fascial layers is essential for the clinician and other health practitioners in finding the best treatment strategy for the patient.

Evolution of the 3-dimensional video system for facial motion analysis: ten years' experiences and recent developments

Since the implementation of the computer-aided system for assessing facial palsy in 1999 by Frey et al (Plast Reconstr Surg. 1999;104:2032-2039), no similar system that can make an objective, three-dimensional, quantitative analysis of facial movements has been marketed. This system has been in routine use since its launch, and it has proven to be reliable, clinically applicable, and therapeutically accurate. With the cooperation of international partners, more than 200 patients were analyzed. Recent developments in computer vision--mostly in the area of generative face models, applying active--appearance models (and extensions), optical flow, and video-tracking-have been successfully incorporated to automate the prototype system. Further market-ready development and a business partner will be needed to enable the production of this system to enhance clinical methodology in diagnostic and prognostic accuracy as a personalized therapy concept, leading to better results and higher quality of life for patients with impaired facial function.

Visual pathway-related horizontal reference plane for three-dimensional craniofacial analysis

OBJECTIVES

To construct three-dimensional (3D) horizontal reference planes based on visual pathway and to determine their stability and reliability by analyzing the structural patterns of normal and dysmorphology for 3D craniofacial analysis.

SETTING AND SAMPLE POPULATION

Thirty-six subjects with maxillofacial dysmorphology and malocclusion, and eight normal controls. MATERIALS AND METHODS POPULATION: On the 3D computed tomographic images of the subjects, the visual pathway-based planes, including the orbital axis plane (OAP), visual axis plane (VAP), and the optical axis plane (OpAP), were constructed and evaluated.

RESULTS

The OAP, but not the VAP and OpAP, showed the ideal relationship between the midsagittal and posterior maxillary plane, and properly described the different patterns of maxillofacial dysmorphology with craniofacial plane 1 of Delaire's analysis and the occlusal plane.

CONCLUSIONS

The proposed visual pathway-related horizontal reference planes, and in particular the OAP, seem to correctly express the visual axis and the position of the head in natural head position and can be used as a horizontal reference plane for the 3D analysis of craniofacial dysmorphology and anthropology.

Reflections on the theory of "silver bullet" octreotide tracers: implications for ligand-receptor interactions in the age of peptides, heterodimers, receptor mosaics, truncated receptors, and multifractal analysis

The classical attitude of Nuclear Medicine practitioners on matters of peptide-receptor interactions has maintained an intrinsic monogamic character since many years. New advances in the field of biochemistry and even in clinical Nuclear Medicine have challenged this type of thinking, which prompted me to work on this review. The central issue of this paper will be the use of somatostatin analogs, i.e., octreotide, in clinical imaging procedures as well as in relation to neuroendocirne tumors. Newly described characteristics of G-protein coupled receptors such as the formation of receptor mosaics will be discussed. A small section will enumerate the regulatory processes found in the cell membrane. Possible new interpretations, other than tumor detection, based on imaging procedures with somatostatin analogs will be presented. The readers will be taken to situations such as inflammation, nociception, mechanosensing, chemosensing, fibrosis, taste, and vascularity where somatostatin is involved. Thyroid-associated orbitopathy will be used as a model for the development of multi-agent therapeutics. The final graphical summary depicts the multifactorial properties of ligand binding.