Maxillofacial trauma: managing potentially dangerous and disfiguring complex injuries [digest]

Patients with maxillofacial trauma require a careful evaluation due to the anatomical proximity of the maxillofacial region to the head and neck. Facial injuries can range from soft-tissue lacerations and nondisplaced nasal fractures to severe, complex fractures, eye injuries, and possible brain injury. Though the Advanced Trauma Life Support (ATLS) guidelines provide a framework for the management of trauma patients, they do not provide a detailed reference for many subtle or complex facial injuries. This issue adds a more comprehensive and systematic approach to the secondary survey of the maxillofacial area and emergency department management of injuries to the face. In addition to an overall review of maxillofacial trauma pathophysiology, associated injuries, and physical examination, this review will also discuss relevant imaging, treatment, and disposition plans. [Points & Pearls is a digest of Emergency Medicine Practice].

SURGICAL TREATMENT OF UPPER AND MIDDLE FACIAL ZONE TRAUMAS IN PROGRESS OF CONCOMITANT TRAUMATIC CRANIOFACIAL INJURIES

In 2012-2015, 207 patients with concomitant craniofacial injuries, who underwent surgical treatment, were observed; among them 176 were men and 31- women. Age of the patients ranged from 16 to 60 years. According to localization and severity of trauma and a priority of surgical intervention, the patients conventionally were divided into 3 groups by the authors: I group (65 patients) - craniofacial injuries; the skull as well as upper and middle areas of face (subcranial and frontobasal fractures) were affected (fractured). II group (80 patients) - severe traumatic injuries of upper and especially middle zones of the face, accompanied with closed craniocerebral trauma, no need in neurosurgery. III group (62 patients) -on the background of serious head traumas, the injuries of face bones were less severe (injury of one or two anatomic areas with displacement of fractured fragments but without bone tissue defects) According to the obtained results a priority was always given to the neurosurgery (vital testimony).The reconstructive surgeries on face skeleton was conducted in combination involving neurosurgeons (I group patients). Reconstructive surgeries of facial bones were conducted in the patients of II group, immediately or at primary deferred period of time but in the patients of III group the surgical procedures for removal of early secondary or traumatic residual fractures have been performed. Reposition of the fractured facial bone fragments was performed in an open way and fixation was carried out by titanium plates and mesh cage (at bone tissue defect). For prevention and elimination of post-traumatic inflammatory processes, the final stage of surgical intervention was: sanation of nasal accessory sinuses and catheterization (5-7 days) of external carotid arteries for administration of antibiotics and other medical preparations. Early and differentiated approach to face injuries, worsening in the course of craniocephalic trauma was not revealed in any patient; there was no evidence of development inflammatory processes in traumatic regions; esthetic and functional results obtained after the surgeries of maxillofacial area were assessed as good and satisfactory.

Upper lip bite test in a patient with McCune Albright syndrome with acromegaly

We report a patient with McCune Albright syndrome with acromegaly and features predictive of difficult airway except a class I upper lip bite (ULB) test. Our patient, a 33-year-old woman, had a history of polyostotic fibrous dysplasia. Tracheal intubation was performed under general anaesthesia. Although we did not find any difficulty in visualizing the glottis by direct laryngoscopy; our patient had multiple poor predictive signs of airway assessment including a Mallampati grade III, restricted neck movement and macroglossia. Our report suggests that the ULB test in people with acromegaly may act as an indicator of easy intubation in spite of other poor predictive signs. However, this finding needs further corroboration by a large study to evaluate the role of the ULB test in people with acromegaly.

A novel oculo-oto-facial dysplasia in a Native Alaskan community with autosomal recessive inheritance

We describe a novel autosomal recessive malformation syndrome in four related individuals from a geographically isolated Native Alaskan community, who have facial defects similar to those of individuals with Treacher Collins (TCS) and Miller syndrome. Distinctive findings include malar and mandibular hypoplasia, lower eyelid coloboma, choanal atresia, orofacial clefting, and external ear malformation with preauricular tags. Intellect is normal and profound mixed hearing loss has been observed in affected adults. Variable extracranial findings include atrioseptal defect, renal dysplasia, and imperforate anus, however, no limb defects have been observed. Cranial imaging studies demonstrate relative prominence of the zygoma, inferior orbital maxillary hypoplasia, and lateral orbital wall defects with an accessory superior bony projection off the zygoma lateral to the orbital rim. We propose that these individuals have inherited a novel autosomal recessive condition we have termed oculo-oto-facial dysplasia (OOFD) with unique radiographic findings.

Effects of tongue volume reduction on craniofacial growth: A longitudinal study on orofacial skeletons and dental arches

The interaction between tongue size/volume and craniofacial skeletal growth is essential for understanding the mechanism of specific types of malocclusion and objectively measuring outcomes of various surgical and/or orthodontic treatments. Currently available information on this interaction is limited. This study was designed to examine how tongue body volume reduction affects craniofacial skeleton and dental arch formation during the rapid growth period in five 12-week-old Yucatan minipig sibling pairs. One of each pair received a standardized reduction glossectomy to reduce tongue volume by 15-17% (reduction group), and the other had the reduction glossectomy incisions without tissue removal (sham group). Before surgery, five stainless steel screws were implanted into standardized craniofacial skeletal locations. A series of cephalograms, lateral and axial, were obtained longitudinally at 1 week preoperative, and 2 and 4 weeks postoperative. These images were traced using superimposition, and linear and angular variables were measured digitally. Upon euthanasia, direct osteometric measurements were obtained from harvested skulls. Five en-bloc bone pieces were further cut for bone mineral examination by dual photon/energy X-ray absorptiometry (DEXA). The results indicate that: (1) while daily food consumption and weekly body weight were not significantly affected, tongue volume reduction showed an overall negative effect on the linear expansion of craniofacial skeletons; (2) premaxilla and mandibular symphysis lengths, and anterior dental arch width were significantly less in reduction than sham animals at 2 and/or 4 weeks after the surgery; (3) both premaxilla/maxilla and mandible bone mineral density and content were lower in reduction than sham animals, significantly lower in anterior mandible; (4) craniofacial skeletal and dental arch size were significantly smaller in reduction than sham animals, being most significant in the mandibular anterior length and ramus height, the anterior dental arch and midface width. These results suggest that reducing tongue body volume in young animals slows craniofacial skeletal growth and anterior dental arch expansion during rapid growth. The mandible, in particular its symphysis portion, and the anterior dental arch width are most affected. These effects may in part contribute to the decrease of functional loads in the anterior mouth by a volume-reduced tongue.

Biomechanical effects of rapid palatal expansion on the craniofacial skeleton with cleft palate: a three-dimensional finite element analysis

OBJECTIVE

To explore the biomechanical effects of rapid palatal expansion (RPE) on the craniofacial skeleton with cleft palate.

DESIGN

A finite element model of a patient's skull with cleft lip and palate (CLP) was generated using data from spiral computed tomographic (CT) scans. Finite elemental analysis (FEA) was performed to depict the physiological changes and stress distribution in craniofacial structures loaded with orthopedic forces that created 5 mm of displacement on the region of the maxillary first premolar and first molar crown.

PATIENTS, PARTICIPANTS

A 14-year-old girl with left complete unilateral CLP was included in this study.

INTERVENTIONS

Spiral CT was carried out prior to any treatment.

MAIN OUTCOME MEASURE(S)

Three-dimensional (3D) features of displacement and stress distribution were analyzed following application of transverse orthopedic force.

RESULTS

Marked amount of displacement and deformation occurred in the dental region. Asymmetric displacement and deformation of UCLP under RPE were evident. The stress generated by RPE was dispersed around the cleft palate and nasal cavity, and was distributed at the buttress of the maxilla-inferior border of the nasal cavity, outboard of the orbit, and central frontal bone near the nasion.

CONCLUSIONS

Application of RPE to UCLP patients induces a pyramid-like displacement of the nasomaxillary complex along with fan-like expansion of the upper dental arch. The uniqueness of RPE with UCLP, however, lies in the asymmetric expansion and dispersed stress distribution around the lateral maxilla buttress and outboard of orbit.

The effects of muscular dystrophy on the craniofacial shape of Mus musculus

Skeletal anomalies are common in patients with muscular dystrophy, despite an absence of mutations to genes that specifically direct skeletogenesis. In order to understand these anomalies further, we examined two strains of muscular dystrophy (laminin- and merosin-deficient) relative to controls, to determine how the weakened muscle forces affected skull shape in a mouse model. Shape was characterized with geometric morphometric techniques, improving upon the limited analytical power of the standard linear measurements. Through these techniques, we document the specific types of cranial skeletal deformation produced by the two strains, each with individual shape abnormalities. The mice with merosin deficiency (with an earlier age of onset) developed skulls with more deformation, probably related to the earlier ontogenetic timing of disease onset. Future examinations of these mouse models may provide insight regarding the impact of muscular forces and the production and maintenance of craniofacial integration and modularity.

Comparative cephalometric study between nasal and predominantly mouth breathers

Aim

to evaluate the possible correlation between the respiratory pattern in determining the craniofacial dimensions, using as baseline the Tweed-Merrifield's cephalometric analysis, added to angle SN-GoGn and to Y axis angle.

Methodology

The selected sample to this study comprised 50 teleradiographies taken in lateral and natural positions of the head in young female patients at the age of 9 to 12 years, presenting mean age of 10 years and 5 months and Class 1 malocclusion. After diagnosis of respiratory pattern, the sample was divided into two groups: control group, 25 teleradiographies of nasal breathers in lateral and natural positions of the head; experimental group, 25 teleradiographies of predominantly mouth breathers in lateral and natural positions of the head.

Results

The results were submitted to descriptive analysis (mean and standard deviation), test F and “t” Student test with significance level of 5%. There was no significant difference between the group with nasal breathing and the group with predominantly mouth breathing for any of the studied variables.

Craniofacial growth and functional change in oligodontia with ectodermal dysplasia: a case report

A case of ectodermal dysplasia in a Japanese boy is presented in this report. After prosthetic treatment was performed with partial dentures in both jaws, mandibular movement, dental casts, and lateral and frontal cephalograms were taken at an initial visit (age 7 years 8 months), and at follow-up 1 year and 8 months later (age 9 years 3 months) to evaluate the developmental changes in masticatory movement, dental arch width, and craniofacial morphology. Stability of the jaw movements improved during the follow-up period both with and without dentures. The facial skeleton grew between the initial visit and follow-up. Mandibular length remained long compared with the average value for Japanese children. A possible genetic marker for mandibular growth (growth hormone receptor), which is considered to be an important factor in mandibular growth and development, was analysed for the gene variant and the result supported the characteristic mandibular growth in the reported case. These results indicate the characteristic craniofacial growth in this disease and emphasize the potential ability of functional development of jaw movements with oligodontia.

Single and combination drug therapy for fetal hemoglobin augmentation in hemoglobin E-beta 0-thalassemia: Considerations for treatment

Patients with hemoglobin E (Hb E)-beta 0-thalassemia, one of the most common hemoglobinopathies worldwide, could benefit from drugs that increase fetal and total hemoglobin levels and thereby decrease the need for transfusions. The long-term clinical outcome of such therapy, its hematologic effects, and which patients are likely to benefit from treatment are unknown. Consequently, the use of such drugs for Hb E-beta 0-thalassemia is limited, and countries where resources for safe and regular transfusion are scarce cannot benefit from them. In a multicenter trial of 42 patients treated with hydroxyurea for two years, almost half the patients demonstrated a significant increase in steady-state hemoglobin level. Drug toxicity was minimal. Combined treatment of hydroxyurea with erythropoietin benefited selected patients, but the addition of sodium phenyl butyrate was ineffective. After 5 years of follow-up, a subset of patients remained off transfusions. Hydroxyurea should be considered for a subset of Hb E-beta 0-thalassemia patients.

Concepts in a multiprong approach to photoaging

Photoaging is a multisystem degenerative process that involves the skin and the skin support systems, including the bone, cartilage, and subcutaneous compartments. These structures provide the architectural support for the dermis, epidermis, and stratum corneum. A multiprong approach to photoaging involves reversing the undesirable changes in each of these structures. Dermatologists should become adept at treating all of the visible manifestations of photoaging.

Bone and aging: Effects on the maxillofacial skeleton

The originally balanced system of normal bone metabolism with an equilibrium of bone resorption and bone formation experiences involutionary changes along with increasing age. This article provides an overview on the effects of aging on bone, in particular on the bone of the maxillofacial skeleton. It explains differences between the postmenopausal type and the senile type of osteoporosis, deals with age-related morphologic changes of bone, mechanisms leading to age-related changes, depicts bones at high fracture risk in aging persons, analyses the reduced bone quantity and quality in cranial bone, and discusses the preservation of maxillofacial bone dimensions by implants. Therefore, research on wound healing, in particular bone healing, and on the regenerative potential of tissue of mesenchymal origin is of major interest and will eventually translate into improved care for patients during daily clinical routine.

A case of McCune-Albright syndrome associated with Gs alpha mutation in the bone tissue

The syndrome of McCune-Albright syndrome (MAS) is clasically defined as a triad presentation with the findings of polyostotic fibrous dysplasia, café-au-lait spots, and sexual precocity. However, not all patients present with complete symptoms. A 52-year-old man was diagnosed as having a variant of McCune-Albright syndrome with the following findings: polyostotic fibrous dysplasia, acromegaly due to pituitary tumor and subclinical hyperthyroidism due to toxic multinodular goiter. Sexual precocity and café-au-lait spots were not noted. Acromegaly was confirmed by laboratory examination (IGF-1, glucose suppression test and TRH stimulation test). Long acting somatostatin analogue was used as treatment. Although the pituitary tumor could not be removed due to technical problems, mass lesions on the cranium were removed subtotally. Histopathological evaluation demonstrated that the lesion complied with fibrous dysplasia. Genomic DNAs were isolated from the craniofacial bones and peripheral leucocytes of the patient. After amplifying the related regions, Gs alpha (Gs alpha) gene was analysed by automatic DNA sequence analysis. An activating mutation of the Gs alpha gene (Arg 201 Cys) was found in the genomic DNA isolated from the bone tissue of the patient, but not in the genomic DNA isolated from the blood. We described a case of MAS associated with Gs alpha mutation in the bone tissue, presenting with polyostotic fibrous dysplasia, subclinical hyperthyroidism and acromegaly.

Prevention of facial fractures from night vision goggle impact

Facial bone fractures in the military can result from direct loading of night vision goggles on the orbital region. Facial fracture research has shown that increasing the area over which the load is applied increases the load tolerance. The purpose of this study is to apply this concept to reducing the risk of facial bone fracture from night vision goggle impacts. The effectiveness of countermeasures in prevention of orbital fracture was evaluated using a vertical drop tower with two impact velocities of 2.6 m/s and 3.6 m/s. The countermeasure used was a rigid plastic custom face shield made from a plaster impression of each head. In addition to two human cadaver subjects, one male and one female, tests were completed on a Hybrid III 50th percentile dummy head. Three impacts to the dummy headform included no countermeasure, safety glasses, and a custom face shield. These tests yielded peak loads of 8700 N, 7500 N, and 5640 N respectively. Using the female subject, impacts were preformed successively until injury occurred. These two impacts to the subject wearing a custom face shield resulted in peak loads of 4025 N and 5158 N. The highest load corresponds to an impact velocity of 3.6 m/s and a nasal bone fracture. Two impacts to the male subject with a custom face shield resulted in peak loads of 4554 N and 5101 N with no injury. The final impact to the male subject had a peak load of 2010 N with complete orbital fracture due to the absence of a countermeasure. From these tests it is shown that facial fracture risk from night vision goggle impact can be reduced using a contoured rigid face shield.

Muscle Influence on Postnatal Craniofacial Development and Diagnostics

The postnatal craniofacial development is determined by exogenous and endogenous factors that may result in morphological and functional muscle changes and influence the dentoskeletal region in terms of a physiologic or dysgnathic development. Using functional appliances, efforts are made to treat skeletal malocclusions through targeted exercise and to prevent an undesirable development of the dentition and the craniofacial structures. However, the success of the treatment and the stability of the outcome are not always adequate. To illustrate the treatment processes, clinically relevant measures for diagnosing muscle function and morphology have been developed in recent years. Electromyographic investigations and bite-force measurements show an excessively high variability and the histologic examinations applied to date are restricted in their suitability for analysis of the human masticatory muscles. Animal experimental studies have meanwhile succeeded in simulating functional jaw orthopedics and in demonstrating muscle remodeling processes at the genetic level. Despite some invasiveness, the time and the small quantity of muscle tissue involved permit molecular biological measuring in the orofacial system.

Influence of the Furlow palatoplasty for patients with submucous cleft palate on facial growth

The purpose of this study was to investigate the facial growth in patients with submucous cleft palate operated on using the Furlow palatoplasty. A total of 30 patients with submucous cleft palate underwent Furlow palatoplasty from 1993 to 1998. The mean follow-up period was 4 years and 3 months. Twenty-five of 30 patients were followed up. Mid-facial growth was measured using lateral cephalograms in 18 patients whose age was greater than 8 years. The parameters obtained in the lateral cephalogram were compared with those of a healthy population in Korea. Eleven (61.1%) of 18 patients observed were within the clinical normal range for the age group for the parameter of the span between the anterior nasal spine and posterior nasal spine, 6 patients (33.3%) were over the range, and 1 patient (5.6%) was below the range. For the sella-nasion-subspinale angle, 55.6% of patients were within the clinical normal range, 27.8% were over the range, and 16.6% were below the range. For the sella-nasion-supramentale angle, 55.6% of patients were within the clinical normal range, 22.2% were over the range, and 22.2% were below the range. For the sella-nasion-subspinale-sella-nasion-supramentale angle, 72.2% of patients were within the clinical normal range, 27.8% were over the range, and none were below the range. For the span between the basion and posterior nasal spine, 50.0% of patients were within the clinical normal range, 27.8% were over the range, and 22.2% were below the range. In conclusion, our results suggest that the Furlow palatoplasty is a useful procedure as an initial treatment of submucous cleft palate and that this technique has a less harmful effect on facial growth because there is no excessive surgical intervention on the hard palate and alveolar process.

Biomechanical and clinical implications of distraction osteogenesis in craniofacial surgery

INTRODUCTION

Craniofacial distraction osteogenesis is an established surgical procedure to correct bony malformations. Force transduction through the osteotomized bone fragments elicits defined biological responses in the gap tissue, which determines the clinical success of the distraction treatment.

OBJECTIVE

The purpose of this investigation was to evaluate clinically a new distraction protocol based on an analysis of the biological and biomechanical parameters executing direct effects on bone regeneration during distraction.

STUDY DESIGN

A multistep distraction protocol was used in 39 patients and the clinical outcome was monitored postoperatively.

RESULTS

All the distraction cases were successful with a single exception. Segmental displacements were stable clinically and radiologically.

CONCLUSION

In order to improve the clinical success of distraction osteogenesis, individual treatment protocols are recommended.

The development of intracranial relations in patients with complete unilateral cleft lip and palate in relation to surgery method and gender aspect

This study focuses on cranium development during puberty growth spurt in patients with complete unilateral cleft of the lip and palate (UCLPc) after use of various surgery methods. Next, this study focuses on cranium development differences between the genders in patients undergoing operations by the same method, as well as comparison of intracranial relations between impaired and healthy individuals. The work is based on longitudinal cephalometric measurement of X-ray films and it is interpreted by cluster analysis. It focuses mainly on mutual interrelations of linear dimensions (meaning longitudinal and vertical) with angular dimensions (characteristic of shape and position). Mutual relationships of linear characteristics were closer than its relationship with the angular characteristics and characteristics of shape and position were mutually closely related than with characteristics of the size. The development of the cranial shape in regards to the linear dimensions is influenced particularly by the depth of maxilla, the length of the ramus of the mandible, and the height of the upper face. The study confirms the least positive development of cranium in boys with a bone graft. Girls undergoing operations with the same technique have the advantage of earlier growth termination of most parts of the cranium, which makes it possible to maintain the results of the therapeutical compensation of the defect.

Gross growth and regrowth of sutures: reflections on some personal research

A series of experiments was performed on young monkeys, rabbits, and turtles to study gross sutural growth of bones. Radiopaque implants in conjunction with serial, direct gross, and indirect radiographic measurements were employed. Differences in growth were observed in the monkey among five facial sutures and also the same suture at different times. Growth was greatest at the zygomaticotemporal suture and least at the premaxillomaxillary suture. In the rabbit, the nasal bone side of the frontonasal suture grew about twice as fast as the frontal bone side. In the turtle shell, the midsagittal suture grew faster than the transverse suture. In all of the animals, the rate of sutural growth decreased with an increase in age. No gross regional growth disturbance was noted after resection of the frontonasal, midpalatine, or transpalatine sutures. The frontonasal suture reformed presumably because of the underlying nasomucoperiosteum, as in a cranial suture, presumably because of the underlying dura. After extirpation of the midpalatine suture with the formation of a complete cleft and despite no underlying membrane, a new suture reformed in an eccentric position in a number of instances. Bone growth at sutures is secondary or compensatory to some other factors.

Progressive osseous heteroplasia in the face of a child

We describe a rare case of progressive osseous heteroplasia of the face in a child. Biopsy showed osteoma cutis superficially with ectopic bone formation in the deeper tissues including skeletal muscle. Analysis of DNA from peripheral blood leukocytes showed mutations in the gene encoding the alpha subunit of the stimulatory G protein of adenylyl cyclase (GNAS1), confirming the diagnosis of progressive osseous heteroplasia.

Study of stress distribution and displacement of various craniofacial structures following application of transverse orthopedic forces--a three-dimensional FEM study

The purpose of this study was to analyze the stress distribution patterns within the craniofacial complex during rapid maxillary expansion. Therefore, a finite element model of a young human skull was generated using data from computerized tomographic scans of a dried skull. The model was then strained to a state of maxillary expansion simulating the clinical situation. The three-dimensional pattern of displacement and stress distribution was then analyzed. Maximum lateral displacement was 5.313 mm at the region of upper central incisors. The inferior parts of the pterygoid plates were also markedly displaced laterally. But there was minimum displacement of the pterygoid plates approximating the cranial base. Maximum forward displacement was 1.077 mm and was seen at the region of the anteroinferior border of the nasal septum. In the vertical plane, the midline structures experienced a downward displacement. Even the ANS and point A moved downward. The findings of this study provide some additional explanation of the concept of correlation between the areas of increased cellular activity and the areas of dissipation of heavy orthopedic forces. Therefore, the reason for the occurrence of sensation of pressure at various craniofacial regions, reported by the patients undergoing maxillary expansion could be correlated to areas of high concentration of stresses as seen in this study. Additionally, the expansive forces are not restricted to the intermaxillary suture alone but are also distributed to the sphenoid and zygomatic bones and other associated structures.

Porous polymethylmethacrylate as bone substitute in the craniofacial area

In craniofacial surgery, alloplastic materials are used for correcting bony defects. Porous polymethylmethacrylate (PMMA) is a biocompatible and nondegradable bone cement. Porous PMMA is formed by the classic bone cement formulation of methylmethacrylate liquid and PMMA powder in which an aqueous biodegradable carboxymethylcellulose gel is dispersed to create pores in the cement when cured. Pores give bone the opportunity to grow in, resulting in a better fixation of the prostheses. We evaluated the long-term results (n = 14), up to 20 years, of augmentations and defect fillings in the craniofacial area, with special interest in possible side effects and bone ingrowth. The evaluation consisted of a questionnaire, a physical examination, and a computed tomography (CT) scan. There were no side effects that could be ascribed to the porous PMMA. Twelve CT scans showed bone ingrowth into the prostheses, proving the validity behind the concept of porous PMMA.

Craniofacial morphology in preschool children with sleep-related breathing disorder and hypertrophy of tonsils

The purpose of this study was to examine craniofacial morphology, pharyngeal airway space and hyoid bone position in preschool children with sleep-related breathing disorder associated with hypertrophy of tonsils (SBDT). Thirty-eight preschool children, mean age 4.7 y, with SBDT and with an apnoea index (AI) of 0 < AI < 5, were divided into two groups. One consisted of 15 children with sleep-related breathing disorder (SBD) and more than 75% of the tonsils visible (GIII) and the other of 23 children with SBD and 25-75% of the tonsils visible (GII). The control group consisted of 31 children without ear, nose and throat disease and with GI (barely visible) tonsils. Compared with the controls, GIII children had a retrognathic mandible, a large posterior facial height, a large interincisal angle with retroclined lower incisors, a narrow pharyngeal airway space, an anterior tongue base position and a long soft palate. Compared with the controls, GII children had a large anterior lower facial height and a short nasal floor. However, like the controls, GII children did not have a retrognathic mandible.

CONCLUSION

The findings show that children with SBDT display a characteristic facial appearance at an early age. Since the condition has an effect on growth, it needs to be prevented by controlling morphology and function at the preschool age.

Cephalometric evaluation of facial types in preschool children without sleep-related breathing disorder

OBJECTIVE

this study was aimed at characterizing the craniofacial structures, i.e. the facial skeleton, cranial base, dentition, pharyngeal airway space, and the hyoid bone position, in healthy preschool children without sleep-related breathing disorder.

MATERIALS AND METHODS

from lateral cephalometric radiographs taken of 92 children for diagnostic purposes, 45 were selected for the present investigation on the basis of head position, and divided according to the classification of Siriwat and Jarabak (Angle Orthod. 55 (1985) 127) into groups representing counter-clockwise (CC), straight downward (SD), and clockwise (C) facial types.

RESULTS

the findings showed that, in comparison with the other groups, CC is associated with larger facial taper and posterior facial height, smaller mandibular line angle, ramus position, lower facial height and cranial base angle. By a similar comparison, C is associated with larger mandibular line, gonial angles and convexity, and with a smaller L-1 to mandibular line angle. There were no significant differences in hyoid bone position among the three groups. However, the distance of the lower pharynx was smaller in CC than in C, while the tongue base of CC was noted to be in a posterior position.

CONCLUSIONS

thus, the results indicate that there are significant differences in the madibular position and form among the present three groups of children. It is proposed that the objective of vertical facial control ought to be included in the treatment of preschool children with malocclusion and respiratory disorder.

Contribution of body habitus and craniofacial characteristics to segmental closing pressures of the passive pharynx in patients with sleep-disordered breathing

Obesity and craniofacial abnormalities may contribute to the pathogenesis of obstructive sleep apnea. The purpose of this study was to evaluate the influence of body habitus and craniofacial characteristics on types of pharyngeal closure. The types of pharyngeal closure were determined by endoscopic evaluations of closing pressures of the passive pharynx in 54 paralyzed and anesthetized patients with sleep-disordered breathing (SDB). Assessment of craniofacial characteristics of the SDB patients and 24 normal subjects were made by lateral cephalometry. As compared with normal subjects, SDB patients demonstrated receded mandibles and long lower faces with downward mandible development. SDB patients with positive closing pressures at both the velopharynx and oropharynx (VP + OP group) demonstrated smaller maxillas and mandibles than those with positive closing pressures at the velopharynx only (VP-only group). Obesity was more prominent in the VP-only group than in the VP + OP group. Our results suggest that obesity and craniofacial abnormalities contribute synergistically to increases in collapsibility of the passive pharyngeal airway in patients with SDB. Furthermore, the relative contribution of obesity and craniofacial anomaly appears to determine the type of pharyngeal closure in SDB.

[Evaluation of the usefulness of vascularized bone grafts for surgical reconstruction of the face]

The process of healing of vascularised bone grafts was examined clinically and the use of vascularised bone grafts in face reconstruction surgery was assessed basing on author's experience with the surgical technique, availability of graft recipient and donor sites and final outcome. Patients enrolled in this study were treated at the Department of Maxillofacial Surgery, Pomeranian Academy of Medicine in Szczecin, for cancer, injuries, developmental anomalies and atrophic changes. In each case it was necessary to restore facial bone structures of functional and aesthetic importance, including: floor of the orbital cavity, alveolar process of maxilla, palate, malar bone and mandible (Tab. 2). Reconstruction was done mostly with parietal bone grafts pedicled on temporal fascia and muscle, coronoid process of the mandible pedicled on temporal muscle, and lower part of the diaphysis of mandible pedicled on masseter and pterygoid muscles. In some cases, reconstruction material consisted of a rib on greater pectoral muscle, clavicle on sternocleidomastoid muscle and scapular bone crest pedicled on trapezius muscle. Free microvascular flaps with some elements of fibula and radius were used in two patients for the reconstruction of mandible and soft tissues. In total, 41 vascularised grafts were performed in 40 patients. Graft healing was examined clinically and usefulness of this technique for face reconstruction surgery was assessed basing on author's experience with the preparation technique, intraoperative complications and extent of trauma to donor sites. The results of healing of specific grafts are enclosed in Table 1. The surgical technique for graft preparation and its transfer into the recipient site varied from case to case. The most difficult and effortful approach was with free bone grafts transferred from remote sites by means of a microsurgical technique (group V). Despite the complexity of the reconstruction method, no intraoperative complications occurred in the course of preparation of the radial and fibular bone grafts. In group IV, the most difficult grafts included those taken from ribs, clavicle and scapular bone. Parietal bone grafts were much less troublesome (subgroups Ia and Ib) although associated with the largest number of intraoperative complications. The easiest preparation method applied to the grafting of coronoid process and lower part of the body of mandible (group II and III). Clinical evaluation of vascularised bone grafts confirmed without reservations the value of this approach in face reconstruction surgery. However, the extent to which individual graft types proved to be usable varied. The most valuable ones included parietal bone grafts pedicled on temporal muscle and fascia used for restoring upper and central facial structures and the coronoid process of mandible pedicled on temporal muscle used for reconstructing the floor of the orbital cavity and alveolar process of the maxilla. Rib grafts pedicled on pectoral muscle were of limited use. The same applies to grafts from the lower part of the body of mandible pedicled on masseter and pterygoid muscles occasionally used for restoring the mental part of mandible. Grafts from remote sites (fibula, radius) should be used only when other reconstruction methods are unavailable.

Determining the optimal time for consolidation after distraction osteogenesis

The consolidation period, one of the biological factors participating in the distraction osteogenesis phenomenon, has not been elucidated. Parameters to assess new bone formation and consolidation in craniofacial distraction have been borrowed from the orthopedic experience. Up until now, the decision to discontinue distraction has been based more on personal experience than on objective data. By using Scintigraphy with Tc99 DP a method has been developed to accurately assess the termination of the consolidation phase. Scintigraphic evidence of consolidation was seen between the fourth and the fifth week after terminating distraction in infants (younger than 12 months). Not before the 10th week in children and between the 10th and the 14th week in adolescents and adults. The data roughly correlates with previous reports. It is believed that the consolidation period should be addressed in biologic terms and not in radiologic terms as done up until now. A method is proposed that offers objective qualitative and quantitative data for the noninvasive evaluation of bone consolidation which could have further applications in distraction of the craniofacial skeleton.

Internal craniofacial distraction with biodegradable devices: early stabilization and protected bone regeneration

Internal craniofacial distraction has several advantages over distraction with external devices. The scars may be less conspicuous; the devices are buried and therefore easier for patients to tolerate; and the devices are more rigidly secured to bone, preventing uncontrolled rotation of the advancing segments. There are several types of internal devices. The Modular Internal Distraction System developed by one of the authors (S.R.C.) and Stryker-Leibinger, Inc. has had widespread use for midface distraction, but requires a substantial surgical procedure for device removal. This is justified in selected children with syndromic craniosynostosis, who frequently need secondary orbitocranial reconstruction at the conclusion of distraction with any type of device. It would be preferable to develop a device that would retain the positive characteristics of the Modular Internal Distraction system, while allowing easy removability. Moreover, the entire distraction procedure would benefit from a technique that would assist in bone regeneration within the distraction gap. Such a biodegradable, stabilizing device may enable early explanation, accelerating the recovery period, while providing fixation of the distraction gap and protected bone regeneration. Accordingly, we have developed a new, biodegradable distraction device with Macropore, Inc. that may be used with the Modular Internal Distraction system to permit easy removability of the device without the need for a large operation for exposure. Second, we have developed a biodegradable stabilizer that permits earlier removal of the distraction device while providing simultaneous fixation and protected bone regeneration. Last, we have demonstrated the feasibility of midcourse correction of the distraction procedure, should this be necessary for whatever reason.

[The aging face in Black Africans]

The face is the part of the human body that most reflects external marks of time. The change of this region concerns the body support as well as the musculo-cutaneous surface. In this survey, we have described its evolution during the life, in the Black African, particularly on the esthetical plane.

[Post-traumatic enophthalmos. Physiopathologic considerations and current therapeutics]

The article is an overview of the available literature on post-traumatic enophthalmos (PTE). The PTE has a clinical definition and its diagnosis is based on a clinical examination. Fully assessment of the deformity requires complete ophthalmological examination and a measurement of the globe backward displacement by the mean of Hertel's ophthalmometer. Focusing on the pathophysiology, we insist on the role of periorbit and extraocular muscle retraction; nevertheless, according to most of the author's, opinion, the main pattern of the PTE seems to be the increased orbital post-traumatic volume, as it can be demonstrated by computed tomography (CT scan). In fact, thorough evaluation of the deformity needs at less a CT scan examination, providing horizontal and coronal slices. Sometimes, even a three-dimensional reconstruction can be obtained, helping the surgeon assessing the orbital deformity pre-operatively. We present five patients victims of a high-energy facial injury (motor vehicular accidents is responsible for an overwhelming majority of cases) leading to severe orbital lesions, and presenting a PTE as the main sequelae. We use homologous bone grafts to repair orbital fractures, especially calvarial bone. Osteotomy of the zygomatic bone (total or partial) can be proposed, combined with grafting of the orbit, to improve the correction of PTE. Most of all, patients with acute orbital trauma must be operated on as quick as possible: the sooner the surgery, the lower the probability for the PTE to occur.

Biomechanical effects of rapid maxillary expansion on the craniofacial skeleton, studied by the finite element method

The aim of this study was to evaluate the biomechanical effect of rapid maxillary expansion (RME) on the craniofacial complex by using a three-dimensional finite element model (FEM) of the craniofacial skeleton. The construction of the three-dimensional FEM was based on computer tomography (CT) scans of the skull of a 12-year-old male subject. The CT pictures were digitized and converted to the finite element model by means of a procedure developed for the present study. The final mesh consisted of 2270 thick shell elements with 2120 nodes. The mechanical response in terms of displacement and von Mises stresses was determined by expanding the maxilla up to 5 mm on both sides. Viewed occlusally, the two halves of the maxilla were separated almost in a parallel manner during 1-, 3- and 5-mm expansions. The greatest widening was observed in the dento-alveolar areas, and gradually decreased through the superior structures. The width of the nasal cavity at the floor of the nose increased markedly. However, the postero-superior part of the nasal cavity was moved slightly medially. No displacement was observed in the parietal, frontal and occipital bones. High stress levels were observed in the canine and molar regions of the maxilla, lateral wall of the inferior nasal cavity, zygomatic and nasal bones, with the highest stress concentration at the pterygoid plates of the sphenoid bone in the region close to the cranial base.

The effect of musculoskeletal facial pain on registration of maxillomandibular relationships and treatment planning: a synthesis of the literature

STATEMENT OF PROBLEM

A significant number of patients exist who are in need of prosthodontic rehabilitation and who at the same time report musculoskeletal pain in the facial area.

PURPOSE

This article, which is based on an assessment of both the past and the most recent basic science and clinical literature, evaluates the effect of musculoskeletal facial pain on two static (physiologic rest position and centric relation) and two dynamic (protrusive border and lateral border movements) maxillomandibular relationships.

MATERIAL AND METHODS

To find the relevant studies addressing the association between musculoskeletal facial pain and maxillomandibular relationships, a MEDLINE search was conducted, which was complemented by a hand search in selected journals.

RESULTS AND CONCLUSIONS

Musculoskeletal facial pain seems to variably affect the aforementioned positions and movements. Hence, the validity of maxillomandibular registrations in patients with existing facial pain is questioned. In those patients with facial pain who simultaneously are in need of a prosthodontic rehabilitation, clinicians should be cautious with regard to the timing of the restorative procedures.

Final height and craniofacial development after surgical resection of craniopharyngioma

Seventeen patients (twelve males and five females) with craniopharyngioma were studied by retrospective review (stature, bone age, and hormone therapy) and by follow-up assessment in all seventeen survivors (stature and craniofacial development). Roentgencephalometric films in the lateral and frontal projections were analyzed. Individual and mean facial diagrams were produced based on 221 reference points in the individual patients and compared to normative data. The posterior cranial base was significantly reduced in length and the cranial base angle was significantly increased. In the facial regions great variations in size and prognathy of the jaws were recorded; on average the patients' maxilla and especially the mandible were short and retrognathic in relation to the anterior cranial base when compared to average adults. Average size and shape of the calvaria, cranial base, and facial regions in the adult male craniopharyngioma group corresponded closely to the average male at the stage of maximum growth in body height, i.e., around 14 years of age. It was concluded that size and morphology of the sphenoid and basioccipital bones were severely affected, possibly as a result of the interfering growth of a craniopharyngioma in childhood. The retrusion of the facial regions might be present as a result of the flattening of the posterior cranial base, but the relatively short and retruded mandible could also be caused by growth hormone deficiency before diagnosis/operation and in periods of sub-optimal therapy. The close resemblance of craniofacial morphology between adult males with craniopharyngioma and normal boys at the time of peak height velocity might reflect the fact that imitation of the natural, optimal balance between growth hormone and sex steroid in puberty is difficult to obtain in therapy.

Component bone marker displacements revealed by image-corrected cephalometric analysis. A lateral cephalometric study of the cranium in normal and craniosynostosis--an implant study

Displacement of bony component anatomy has not been comprehensively described in human cranial development. In this study, tantalum implants were used to define cranial bone position on serial cephalometric surveys. Image correction (ICCA method) was used to eliminate artifactual shift of component markers before serial analysis was used to define implant movement. In addition, applicable normative standards were used to assess all case presentations. Three normal subjects comprised a normal mixed longitudinal sample aged 2 to 84 months. Two plagiocephaly subjects were studied, one from 6 to 77 months and the other from 16 to 44 months of age. Three syndromic craniosynostosis subjects demonstrated both abnormal and normalized growth following craniotomy, from 14 to 45, from 0.5 to 5.5, and from 2 to 75 months of age. A pattern of backward rotation of cranial component anatomy was observed in three normal subjects and two plagiocephaly subjects. The posterior fossa (PF) showed the greatest growth activity, with displacement adjustments throughout the study, and the anterior cranial fossa (ACF) least growth activity, with imperceptible frontal bone movement after age 3 years. After traditional bifrontal craniotomy, an abnormal displacement growth pattern was observed from age 14 to 45 months in the patient with syndromic craniosynostosis (Pfeiffer syndrome). Extensive fronto-parietal "bossing" and grossly deficient movement in the PF were observed. However, after a bifrontal craniotomy that also crossed lambdoid sutures, a normalized pattern of displacement growth was observed in two Apert syndrome patients. These two patients with extensive syndromic craniosynostosis had cranial component pattern adjustments as in the normal and plagiocephalic subjects.

[Effect of breathing mode and nose ventilation on growth of the facial bones]

Correlations between breathing mode and craniofacial morphology were investigated in 47 children at the ages of 6-15 years (average, 9.9 years). Apart from history and clinical examination, nasal endoscopy, rhinomanometry and measurements of cephalometric radiographs were included in the analysis. After separating the patients into a "normal face" group and a "long face" group by measuring the angle between the frontal skull base and the mandibular plane, we analyzed the data in attempting to correlate nasal obstruction with craniofacial development. Findings demonstrated a significant predominance of mouth-breathing compared to nasal breathing in the vertical growth patterns studied. Furthermore, significant differences were found during nasal endoscopy in the growth pattern and were attributed to large adenoids. These findings were confirmed separately in all patients up to the age of 9 years, but differences were clearer. Rhinomanometry and planimetric measurements of the sizes of the adenoids in craniofacial radiographs showed no unambiguous differences between the patient groups. Our present study was not able to establish clear causal correlations between mouth-breathing, craniofacial development and adenoid size, suggesting that existing genetically determined craniofacial growth patterns are modulated by exogenic influences. Nonetheless, our results show a correlation between obstructed nasal breathing, large adenoids and vertical growth patterns.

Transverse dentofacial structure of young men who have undergone surgical correction of unilateral cleft lip and palate: a posteroanterior cephalometric study

The transverse dentofacial structure of 34 young adult males with unilateral cleft lip and palate, studied by means of posteroanterior cephalograms, was compared to that of a normal sample of 102 young adult males. All cleft patients had been treated surgically and orthodontically in accordance with a standardized protocol. Orthognathic surgical treatment was carried out when growth had ended in a few subjects. In studying the posteroanterior cephalograms, eight lengths, 10 ratios, and three angular variables were used. Comparison of the cephalometric values of the subjects with cleft palate and the normal sample of young adult males indicated (1) the absence of any significant differences in angular variables describing the transverse dentoalveolar relationships in the maxillary and mandibular incisal regions as well as the mandibular position; (2) the absence of any significant differences in the ratios of the nasal, maxillary, and mandibular widths to the interorbital width; (3) the presence, in the cleft group of significantly decreased ratios of maxillary intermolar width to interorbital width, mandibular intermolar width to interorbital width, maxillary intermolar width to mandibular intermolar width, and maxillary intermolar width to maxillary width; (4) the presence, in the cleft group, of a significantly increased ratio of innerorbital width to interorbital width; and (5) significant correlations between the maxillary and mandibular molar widths in the cleft group.

The radiographic evaluation of sinonasal tumors: an overview

It is axiomatic that advances in head and neck imaging improve our understanding of head and neck diseases. Dramatic improvements in radiologic imaging in recent years have, as a corollary, dramatically improved our understanding of sinonasal tumors. Older techniques such as plain film radiography and multidirectional tomography poorly delineate normal anatomy and pathologic changes in the craniofacial region. Modern imaging modalities depict sinonasal tumors and their metastases in detail, yielding information that allows treatment planning to proceed rationally. The radiologic examination is commonly employed as a precise "map" for implementation of therapy, and imaging studies are essential in the follow-up evaluation for tumor residual or recurrence. This article provides an overview of the current contributions made by head and neck radiology to the understanding and clinical management of sinonasal tumors.

Healing of experimentally created defects: a review

Within cranio-maxillofacial surgery and orthopedic surgery a bone graft or a bone substitute is required to recontour or assist bony healing in repair of osseous congenital deformities, or in repair of deformity due to trauma or to surgical excision after elimination of osseous disease processes exceeding a certain size. An autogenous bone graft is the optimal material of choice, however its use is problematic due to donor site morbidity, sparse amounts and uncontrolled resorption. Immunological responses and risk of viral contamination of allogenous and xenogenous bone materials make the use of these materials questionable. Healing and degradation of alloplastic materials are inconsistent with subsequent restricted use. The principle of guided tissue regeneration excluding soft tissue cells from a certain area is not alone sufficient to insure complete bony healing. Recombinant bone morphogenetic proteins have with success been added as adjuncts to already known biomaterials. In the future, inductive materials together with a suitable carrier and a biodegradable membrane may be the choice of bone substitute used within cranio-maxillofacial and orthopaedic surgery.

Irradiated bone and its management

There are two undeniable attributes of radiotherapy: its value in controlling head and neck malignancies and the progressive damage it inflicts on all treated tissues. It is fortunate that over the past decade, we have developed techniques and treatments that counteract, at least in part, the negative effects of radiotherapy on bone. Some of these measures are purely preventive and must be employed before or during radiation therapy to be successful. They include limiting the total radiation dose to less than 7000 Rads, appropriately shielding structures that do not require radiation, sparing one or more major salivary glands to minimize xerostomia, limiting fraction dosages to less than 200 Rads, obtaining pre-radiation dental evaluations, and performing dental extractions before radiotherapy begins. Additionally, treatments have been devised to prevent ORN following radiotherapy. They consist of patient participation in aggressive dental maintenance programs, oral fluoride treatments, and the use of preextraction hyperbaric oxygen when unhealthy teeth need to be removed. Should radiation-induced complications develop in spite of these efforts, treatments have been developed that effectively deal with ORN, namely, hyperbaric oxygen (the Marx protocol) and prolonged courses of intravenous antibiotics. Finally, when ORN results in mandibular loss and deformity, these defects can be effectively reconstructed with either corticocancellous particulate bone grafts or microvascular osseous tissue transfers, depending on the clinical situation. Much can be done to prevent and treat radiation-induced complications involving bone, and it remains the responsibility of the head and neck surgeon to make sure that these measures are utilized. When all priorities in treating ORN are considered, differentiating a radiation-induced wound healing problem from a delayed tumor recurrence remains paramount. This differentiation should always be the first step in the treatment of any radiation-induced wound.

Facial bone wound healing. An overview

Facial bone wound healing has practical importance not only in acute fracture repair, but also in head and neck surgery. Fundamental principles of fracture fixation are now understood, and the benefit of acute bone grafting has emerged. In the future, bone healing may be augmented with growth factors and implants incorporating cells grown in tissue culture.

Effects of prostaglandins on the skeleton

Prostaglandins (PGs), particularly those of the E series, have potent effects on bone resorption in vitro and on bone formation, bone remodeling, and bone modeling in vivo. When given systemically, PGEs have powerful anabolic effects--increasing bone formation rates, bone modeling in the formation mode, and remodeling with a net increase in bone mass. When applied locally, PGE1 increases periosteal bone formation and alveolar bone mass, and appears to promote periodontal soft-tissue regeneration. PGs have potential clinical application in the local restoration or augmentation of bone mass, focal stimulation or bone formation, and the regeneration of soft tissues associated with osseous tissues, such as fibrous and ligamentous insertions into bone.

Bone grafting in craniofacial surgery

Bone graft surgery is the basis of all craniofacial surgery. The use of bone grafts in the craniofacial region has changed from a basic trial-and-error concept of surgical triumph to the understanding of the fundamental concepts of bone healing and bone physiology. The search for the super graft continues, and may become a reality before the end of the millennium.

Impact tolerances of the rigidly fixated maxillofacial skeleton

A study was designed to determine how soon an athlete who undergoes rigid fixation of a facial fracture can return to full competition. The impact resistance of a rigidly fixated malar complex fracture was studied and compared with that of an intact malar complex. Twelve fresh human cadaver heads were used. A custom-designed impact device was used to deliver a blow of a specific energy to each intact malar complex. The subsequent fractures were rigidly fixated at three points using titanium miniplates and screws. A second impact of identical energy was delivered. The forces generated and the subsequent displacement of hard and soft tissues were recorded after each impact. It was concluded from this study that an impact to a rigidly fixated malar complex fracture produced less force and greater displacement of hard and soft tissues than an impact of identical energy to an intact malar complex. The potential for sustaining more severe maxillofacial injuries after an initial facial fracture should be seriously considered. The results suggest that sufficient time should be allowed for the bony healing of a facial fracture to occur, even after rigid fixation, before an athlete can resume full contact activities.

Facial balance in cleft lip and palate. I. Normal development and cleft palate

A full understanding of balanced facial growth, based on a complete knowledge of the anatomy and physiology of the region, is essential if cleft lip and palate is to be treated successfully. The cleft abnormality is the cause of underdevelopment and subsequent loss of function. Cleft surgery must aim to restore normal anatomy and physiology with emphasis on muscle reconstruction of the lip and soft palate if normal facial development is to be achieved.

Facial balance in cleft lip and palate. II. Cleft lip and palate and secondary deformities

The cleft abnormality is the cause of underdevelopment and subsequent loss of function. Primary cleft surgery and surgery to correct the secondary deformities of previous non-functional repair should aim to restore normal anatomy and physiology, with an emphasis on muscle reconstruction of the lip and soft palate if normal facial development is to be encouraged.