Craniofacial Anatomy Research Articles

Cephalometric analysis for microvascular head and neck reconstruction

While a large body of literature exists involving normative measurements for the craniofacial skeleton, few have analyzed the necessary dimensions that are pertinent in reconstruction using microvascular free flaps. Cephalometric analysis was performed using 3-dimensional CT scans from 70 adults. Relevant dimensions of the fibula were obtained from a subset of 20 patients. Normative cephalometric values, including various distances and angles, for the mandible and maxilla were obtained and compared to the dimensions of the fibula. Comparisons were made between measurements from men and women, and patients with full dentition and edentulous patients. Schematics for designing mandibular and maxillary reconstructions are presented. When premorbid craniofacial anatomy cannot be discerned in the setting of extensive trauma or tumor involvement, normative dimensions may be a helpful guide for flap design and should be in the armamentarium of surgeons engaged in complex head and heck reconstruction.

Direct 3D Cephalometric Analysis Performed on CBCT

Cone Beam Computed Tomography produces distortion-free and accurate images of the craniofacial anatomy, and can be considered as a useful instrument to perform a correct diagnosis and treatment using a cephalometric analysis. Now a days the 3D cephalometric analysis are made by adapting on 3D what was born on 2D, so it can be necessary to find a new technique that was born directly on 3D.Sixty-five Ricketts’ first skeletal classes were chosen in an archive of 700 CBCT acquisitions. 3 easily repeatable reference planes were found on each case and then 15 points were selected on the skull, for a total of 18 cephalometric points. Each point of these 65 patients creates a cloud of points that could represent the range of normality in the 3D space. The coordinates of each analyzed point presented a standard deviation between 0, 00 and 5, 64. This range of values may be considered representative for the first skeletal class.Authors agree that further studies are needed but the Direct 3D cephalometric analysis may be considered a new easy, precise and rapid way to reach a correct diagnosis and treatment with a cephalometric analysis born directly on 3D.

Pediatric Maxillary Fractures

Pediatric craniofacial structures differ from those of adults in many ways. Because of these differences, management of pediatric craniofacial fractures is not the same as those in adults. The most important differences that have clinical relevance are the mechanical properties, craniofacial anatomy, healing capacity, and dental morphology. This article will review these key differences and the management of pediatric maxillary fractures. From the mechanical properties' perspective, pediatric bones are much more resilient than adult bones; as such, they undergo plastic deformation and ductile failure. From the gross anatomic perspective, the relative proportion of the cranial to facial structures is much larger for the pediatric patients and the sinuses are not yet developed. The differences related to dentition and dental development are more conical crowns, larger interdental spaces, and presence of permanent tooth buds in the pediatric population. The fracture pattern, as a result of all the above, does not follow the classic Le Fort types. The maxillomandibular fixation may require circum-mandibular wires, drop wires, or Ivy loops. Interfragmentary ligatures using absorbable sutures play a much greater role in these patients. The use of plates and screws should take into consideration the future development with respect to growth centers and the location of the permanent tooth buds. Pediatric maxillary fractures are not common, require different treatments, and enjoy better long-term outcomes.

Three‐dimensional analysis of deciduous maxillary anterior teeth using cone‐beam computed tomography

The recent introduction of cone-beam computed tomography (CBCT) into the medical field has allowed the nondestructive investigation of internal structures at relatively low cost and radiation exposure. The accuracy of CBCT in both two and three dimensions has been demonstrated, and CBCT has been used successfully for craniofacial anatomy. Knowing the anatomical structure of deciduous teeth is essential for clinical dentistry. However, the root structure of deciduous teeth is rarely reported because of the scarcity of intact deciduous teeth without root resorption. The aim of this study was to evaluate the intact root form of deciduous teeth using CBCT. Data from 38 young children was analyzed using an image-analyzing program. The degree of buccal dilacerations was 26.3° for deciduous maxillary central incisors (DMA), 16.5° for deciduous maxillary lateral incisors (DMB), and 17.5° for deciduous maxillary canines (DMC) in about half of the root length. The crown-to-root ratios were 0.52 for DMA, 0.48 for DMB, and 0.52 for DMC. These data will be helpful for understanding the development of dentition, and for clinical dentistry.

Unique Features of the Pediatric Craniofacial Anatomy

From the Division of Plastic and Reconstructive Surgery, Department of Surgery, School of Medicine, University of Miami Miller; and Jackson Memorial Hospital, Miami, Florida. Received September 7, 2010. Accepted for publication November 14, 2010. Address correspondence and reprint requests to Rosiane A. Roeder, MD, MPH, 1611 NW 12th Ave, RM-88, Miami, FL 33135; E-mail: [email protected] The authors report no conflicts of interest.

Cone Beam Computed Tomography: A Link with the Past, a Promise for the Future

During the last quarter of the 20th century, changes in clinical orthodontics were largely driven by improvements in bracket design, attachment mechanisms, and arch wire materials. This focus on the mechanical aspects of treatment led to decreased clinical interest in the underlying biology of facial growth and, for a time, craniofacial practitioners often ignored the bio in biomechanics. There was even more disappointment after the completion of the Human Genome Project. Although this project promised exciting possibilities for biologically based manipulation of the growing face, the resulting data were interesting but in most cases not clinically useful. In 2001, the introduction of low-cost, low-radiation dose, high-resolution cone beam computed tomography (CBCT) in clinical orthodontics created the potential for new discoveries in craniofacial biology and facial growth. This technology provides researchers and clinicians with the tools needed to study 3-dimensional changes in craniofacial anatomy associated with the growth process and clinical care. In the 20th century, radiographic cephalometry was a pioneering advance that led to many fundamental insights into the behavior of the face and neurocranium during growth. CBCT imaging promises similar advances in the 21st century. However, to take advantage of this opportunity, clinicians will need to interpret 3D anatomic changes in the context of the underlying growth process. This paper presents a short history of imaging in orthodontics, reports on the current state of the art, and suggests 3 ways CBCT imaging may influence the future of the specialty.

Practical Applications of Cone-Beam Computed Tomography in Orthodontics

Comprehensive visualization and records of the craniofacial complex have been goals in orthodontic imaging. These tasks have been performed by means of plaster, photographs and radiographs. These approaches have evolved across time, and cone-beam computed tomography (CBCT) has emerged as a comprehensive imaging modality for orthodontics. The authors provide a practical guide for applying CBCT in orthodontics, with an emphasis on situations in which conventional imaging is limited. These situations include dental development, limits of tooth movement, airway assessment, craniofacial morphology and superimposition. Complexities of the craniofacial complex, dentition and airway present challenges in obtaining conventional images. CBCT has image-fidelity advantages over conventional imaging that can lead to improved visualization. CBCT is changing orthodontics with respect to clinically assessing patients and is evolving with respect to diagnosis, clinical techniques and outcomes. The clinical value proposition of CBCT is to describe craniofacial anatomy accurately and provide comprehensive information regarding anatomical relationships and individual patient findings for improved diagnosis, treatment planning and prognostication.

Prenatal Ultrasound Diagnosis in 51 Cases of Holoprosencephaly: Craniofacial Anatomy, Associated Malformations, and Genetics

To analyze the prenatal ultrasound findings of the craniofacial and extracephalic anatomy, the postnatal pathological findings, and the genetic anomalies in 51 cases of holoprosencephaly (HPE). Between 1990 and 2005, a collective of 51 fetuses with tentative ultrasound diagnosis of HPE was recruited at two tertiary referral centers for prenatal ultrasound diagnostics via the Pia Fetal Database (GEMedical Systems, Webling, Germany). Cephalic as well as extracephalic anomalies were investigated, and all cases were subdivided into the subgroups lobar, a lobar, and semilobar HPE. In addition to the ultrasound investigation, 45 fetuses were analyzed for genetic anomalies and 21 fetuses underwent an autopsy. The average age at diagnosis was 21.9 weeks of gestation. There was a greater number of female fetuses, with an overall ratio of 2.67:1. In 61% of all cases, there was a reduction of growth in comparison with healthy fetuses of the same age. Within the second trimenon, the cephalic anomalies became evident when investigating the diameter of the fetal head (second trimenon: 71%below the fifth percentile; third trimenon: 92% below the fifth percentile). In 82%of the cases, extracephalic anomalies were diagnosed additionally. In 63%, the diagnosis of holoprosencephaly led to a termination of pregnancy. Ten percent of the fetuses were born alive. In 81% of the cases, the diagnosis of HPE was confirmed postnatally. The remaining 19% showed other severe cephalic and extracephalic anomalies. Chromosomal anomalies were detected in 79% of the fetuses, most frequently trisomy 13 (59%). Because of recent advances in the development and improvement of high-resolution ultrasound, early diagnosis of congenital anomalies such as HPE is now possible. In this study, which represents the largest collection of prenatally diagnosed HPE reported in the literature to date, the average age at diagnosis was earlier than in other studies. The ultrasound devices of today provide excellent images of the fetus that allow an exact diagnosis of craniomaxillofacial anomalies as well as extracephalic anomalies. Apart from a very few cases, the diagnosis of HPE is incompatible with life.

Contemporary Issues in Head and Neck Pathology and Radiology

The comprehensive evaluation, assessment, and management of patients with non-tooth-related conditions of the head and neck area are essential aspects of the practice of dental medicine. The manuscripts selected for publication in this special issue serve to illustrate the importance of close cooperation between oral and maxillofacial pathology, radiology, oral medicine, and head and neck anatomy in both the initial diagnostic and subsequent treatment phases when evaluating and treating patients with non-tooth-related conditions of the oral and maxillofacial complex. I would like to genuinely thank my Guest Editors, Dr. Neil S. Norton from Creighton University in Omaha, Neb, USA Dr. Preetha P. Kanjirath, from the University of Michigan at Ann Arbor, Mich, USA and Dr. Tarnjit Saini, Brooke Army Medical Center Fort Sam Houston, in San Antonio, Tex, USA for their assistance. Without their involvement and thoughtful discussions, this special issue would not have been possible. I also extend my thanks to the authors who have contributed to this special issue, as well as to the many reviewers who graciously volunteered with the peer-review process. In the lead article in this special edition, “Bone Diseases of the Jaws”, by P. J. Slootweg, provides an overview of the more common and/or important lesions occurring in the oral and maxillofacial complex, while emphasizing the considerable overlap in clinical, histological, and radiological features among these entities. Y. Morimoto and colleagues review the usefulness of ultrasound imaging for the detection of noninvasive and soft tissue-related diseases and introduce three new potential applications of ultrasonography: guided fine-needle aspiration, measurement of tongue cancer thickness, and diagnosis of metastasis to cervical lymph nodes. Subsequent manuscripts explore the relationship between craniofacial pathology and anatomy. L. Sonnesen summarizes recent studies on the link between morphological deviations of the cervical vertebral column and craniofacial morphology, while Guest Coeditor Neil S. Norton and colleagues employ volumetric tomography to review the anatomy of the greater palatine canal and also to rule out a statistically significant association between the prevalence of maxillary sinus disease and the presence of concha bullosa and/or nasal septal deviation. R. A. Mesquita and colleagues critically review the available literature on the nonsurgical treatment of oral leukoplakia, while E. de S. Tolentino and colleagues present a well-documented case of an ameloblastic fibroma that illustrates the need to integrate radiology, oral and maxillofacial pathology, and head and neck anatomy in both the initial diagnosis and subsequent treatment of lesions of the maxillofacial complex. On behalf of my Guest Coeditors and myself, I hope that you will find the manuscripts that comprise this special issue both interesting and informative. Paul C. Edwards Preetha P. Kanjirath Tarnjit Saini Neil S. Norton

Developmental craniofacial anthropometry: Assessment of race effects.

Differences in craniofacial anatomy among racial groups have been documented in a variety of structures, but the oral and maxillofacial regions have been shown to be a particularly defining region of variability between different racial/ethnic groups. Such comparisons are informative, but they neither address developmental changes of the craniofacial anatomy nor do they assess or take into account the natural variability within individual races that may account for similar reported, across-group variations. The purpose of this report was to compare-using medical imaging studies-the growth trend of select race-sensitive craniofacial variables in the oral and pharyngeal regions when all races [White, Asian, Black, and Hispanic (AR)] are included versus only a single race category [White (WR)]. Race effect was tested by comparing sex-specific growth fits (fourth degree polynomial model) for AR versus WR data. Findings indicate that the inclusion of all races versus a single race did not significantly alter the growth model fits. Thus, the inclusion of all races permits the advancement of general growth models; however, methodologically, it is best to treat the race variable as a covariate in all future analysis to test for both potential all race effects or individual race effects, on general growth models.

Prenatal Ultrasound Diagnosis in 51 Cases of Holoprosencephaly - Craniofacial Anatomy, Associated Malformations and Genetics

Prenatal Ultrasound Diagnosis in 51 Cases of Holoprosencephaly - Craniofacial Anatomy, Associated Malformations and Genetics

Frontofacial Monobloc Distraction Using the StealthStation Intraoperative Navigation System

The frontofacial monobloc advancement is a safe, effective, and cosmetically acceptable treatment of frontal and midface retrusions present in craniofacial syndromes. Although a number of modifications have been put forward to supplement this procedure, the basic steps of cleaving the facial skeleton from the skull base remain the same. We present a case where intraoperative navigation was used to visualize the craniofacial anatomy while the bone cuts were made for this cleaving process. This technique visually demonstrates parts of this procedure that were hitherto performed solely using tactile and auditory inputs superimposed on a 3-dimensional model of the craniofacial anatomy in the surgeon's mind. This technique offers a significant advantage for teaching purposes, in performing cases with complex anatomy and for accurate positioning of the distractor devices.

Predicting optimal continuous positive airway pressure in Japanese patients with obstructive sleep apnoea syndrome

Several algorithms that predict the optimal CPAP have been developed for Caucasian patients with OSA syndrome, but these algorithms do not allow for racial differences in craniofacial anatomy. We investigated whether an equation that included data on craniofacial structure, physique and severity of OSA could more accurately predict the optimal CPAP for Japanese patients with OSA syndrome. In 170 Japanese patients with OSA syndrome, the optimal CPAP was determined by manual titration during polysomnography. An equation predicting the optimal pressure was derived from anthropometric, polysomnographic and cephalometric data. This equation was validated in another 110 Japanese patients with OSA syndrome. Stepwise multiple regression analysis identified AHI, BMI, mean SaO(2) and a cephalometric parameter: the angle between a line from point B to the menton (Me) and a line from Me to the hyoid bone (H) (BMeH), as independent predictors of optimal CPAP. The following equation was constructed to predict the optimal CPAP: 27.78 + (0.041 x BMeH) + (0.141 x BMI) + (0.040 x AHI) - (0.312 x mean SaO(2)). This equation accounted for 47% of the variance in optimal pressure (R(2) = 0.47, P < 0.0001). The measured optimal pressure and the pressure calculated using this equation were very similar in the other 110 patients with OSA syndrome (9.5 +/- 3.0 and 9.2 +/- 2.1 cmH(2)O, respectively). Optimal CPAP was more accurately predicted by combining a cephalometric parameter with BMI and polysomnographic data in Japanese patients with OSA, suggesting that craniofacial structure may be important in the pathogenesis of OSA syndrome among Asians.

Craniofacial Profile Assessment in Patients with Obstructive Sleep Apnea

Craniofacial Profile Assessment in Patients with Obstructive Sleep Apnea

Identifying people at high risk for developing sleep apnea syndrome (SAS): a cross-sectional study in a Pakistani population

BackgroundObstructive Sleep Apnea (OSA) is associated with many cardiovascular and psychiatric diseases. Day-time sleepiness is a common consequence of sleep apnea and correlates with road-traffic accidents (RTA). Pakistan has a high prevalence of factors which predispose an individual to OSA and death from RTAs are a huge burden. However there is a dearth of prevalence studies in this regard. We aim to understand local relevance of the disease and estimate the prevalence of individuals high-risk for OSA.MethodsThis cross-sectional survey was conducted among 450 individuals at Aga Khan University Hospital (AKUH), which is a tertiary care teaching hospital in Pakistan. We used the BQ as our measurement tool. Based on the responses, participants were grouped into high or low-risk for OSA.ResultsOur study sample size was 418 with 63.2% males. Mean age of our study population was 30.4 SD +/- 12.3 years; and mean BMI was 23.2 SD +/- 5 kg/m2. Out of the total sample size 24.9% reported snoring and there were twice as many males who snored as compared to females. Forty-five individuals reported that they had nodded off to sleep while driving at least once in their lifetime. On the other hand, the highest proportion of high risk individuals 47.6% was found in the age group 60 or above. The overall prevalence of individuals who were high risk for sleep apnea was 10%.ConclusionA significant proportion of the population is at high-risk for OSA. Our study shows that despite low BMI and favorable craniofacial anatomy sleep apnea is still a locally relevant disease. Given the local relevance of OSAS, it is important to increase awareness among general population but more importantly among physicians of the developing countries, like Pakistan, about common clinical features and pertinent risk factors and complications of OSAS.

Analyse céphalométrique tridimensionnelle à 14 points : compensations des dysmorphies maxillo-faciales

The eight points cephalometric Treil model and the alveolodental parameters already allows an initial description of the maxillofacial framework and the teeth. Added six points allows taking into consideration an intermediate level: the maxillary and mandibular skeletal basis. So, the 14 points complete model allows a complete craniofacial anatomy description in three analysis levels: the framework or envelope, the osseous bases, the alveolodental arch. The correlation study between the 3D parameters at different levels defines the compensation notion. It allows understanding how skeletal disharmony may be distributed among the different levels. Only vertical direction compensations are analysed here.

The genesis of cartilage size and shape during development and evolution.

How do cartilaginous elements attain their characteristic size and shape? Two intimately coupled processes underlie the patterned growth of cartilage. The first is histogenesis, which entails the production of cartilage as a discrete tissue; the second is morphogenesis, which pertains to the origins of three-dimensional form. Histogenesis relies on cues that promote the chondrogenic differentiation of mesenchymal cells, whereas morphogenesis requires information that imbues cartilage with stage-specific (e.g. embryonic versus adult), region-specific (e.g. cranial versus appendicular) and species-specific size and shape. Previous experiments indicate that early programmatic events and subsequent signaling interactions enable chondrogenic mesenchyme to undergo histogenesis and morphogenesis, but precise molecular and cellular mechanisms that generate cartilage size and shape remain unclear. In the face and jaws, neural crest-derived mesenchyme clearly plays an important role, given that this embryonic population serves as the source of chondrocytes and of species-specific patterning information. To elucidate mechanisms through which neural crest-derived mesenchyme affects cartilage size and shape, we made chimeras using quail and duck embryos, which differ markedly in their craniofacial anatomy and rates of maturation. Transplanting neural crest cells from quail to duck demonstrates that mesenchyme imparts both stage-specific and species-specific size and shape to cartilage by controlling the timing of preceding and requisite molecular and histogenic events. In particular, we find that mesenchyme regulates FGF signaling and the expression of downstream effectors such as sox9 and col2a1. The capacity of neural crest-derived mesenchyme to orchestrate spatiotemporal programs for chondrogenesis autonomously, and to implement cartilage size and shape across embryonic stages and between species simultaneously, provides a novel mechanism linking ontogeny and phylogeny.

Hong Kong craniofacial dissection workshop: a first for FGDP(UK)'s implant dentistry diploma

The diploma in implant dentistry, one of many successful educational programmes developed by the FGDP(UK), comprises 16 weekend units of study culminating in a rigorous assessment. Integral to the course is a craniofacial anatomy module, in which under supervision the participants perform a sequence of detailed dissections on cadaver heads, with a view to reinforcing their understanding of surgical anatomy relevant to general and implant dentistry. Interspersed with the dissection sessions are five or six tutorials, each intended as a prelude to the dissection exercise.

A Virtual Reality Atlas of Craniofacial Anatomy

Head and neck anatomy is complex and represents an educational challenge to the student. Conventional two-dimensional illustrations inherently fall short in conveying intricate anatomical relationships that exist in three dimensions. A gratis three-dimensional virtual reality atlas of craniofacial anatomy is presented in an effort to address the paucity of readily accessible and customizable three-dimensional educational material available to the student of head and neck anatomy. Three-dimensional model construction was performed in Alias Maya 4.5 and 6.0. A basic three-dimensional skull model was altered to include surgical landmarks and proportions. Some of the soft tissues were adapted from previous work, whereas others were constructed de novo. Texturing was completed with Adobe Photoshop 7.0 and Maya. The Internet application was designed in Viewpoint Enliven 1.0. A three-dimensional computer model of craniofacial anatomy (bone and soft tissue) was completed. The model is compatible with many software packages and can be accessed by means of the Internet or downloaded to a personal computer. As the three-dimensional meshes are publicly available, they can be extensively manipulated by the user, even at the polygonal level. Three-dimensional computer graphics has yet to be fully exploited for head and neck anatomy education. In this context, the authors present a publicly available computer model of craniofacial anatomy. This model may also find applications beyond clinical medicine. The model can be accessed gratis at the Plastic and Reconstructive Surgery Web site or obtained as a three-dimensional mesh, also gratis, by contacting the authors.

A web-based instruction module for interpretation of craniofacial cone beam CT anatomy

To develop a web-based module for learner instruction in the interpretation and recognition of osseous anatomy on craniofacial cone-beam CT (CBCT) images. Volumetric datasets from three CBCT systems were acquired (i-CAT, NewTom 3G and AccuiTomo FPD) for various subjects using equipment-specific scanning protocols. The datasets were processed using multiple software to provide two-dimensional (2D) multiplanar reformatted (MPR) images (e.g. sagittal, coronal and axial) and three-dimensional (3D) visual representations (e.g. maximum intensity projection, minimum intensity projection, ray sum, surface and volume rendering). Distinct didactic modules which illustrate the principles of CBCT systems, guided navigation of the volumetric dataset, and anatomic correlation of 3D models and 2D MPR graphics were developed using a hybrid combination of web authoring and image analysis techniques. Interactive web multimedia instruction was facilitated by the use of dynamic highlighting and labelling, and rendered video illustrations, supplemented with didactic textual material. HTML coding and Java scripting were heavily implemented for the blending of the educational modules. An interactive, multimedia educational tool for visualizing the morphology and interrelationships of osseous craniofacial anatomy, as depicted on CBCT MPR and 3D images, was designed and implemented. The present design of a web-based instruction module may assist radiologists and clinicians in learning how to recognize and interpret the craniofacial anatomy of CBCT based images more efficiently.