Biomedical subjects

Robert J Havlik

Publications and source records attributed to Robert J Havlik.

8 recordsLinked to original sources

PubMed2005

The spectrum of orofacial clefting.

LEARNING OBJECTIVES: After studying this article, the participant should be able to: 1. Describe the differing types of congenital clefting defects that extend outward from the perioral region. 2. Define the sites of anatomical disruption and deformities that these types of facial clefts cause. 3. Describe the cause and incidence, if known, of orofacial clefts and their inheritance/transmission risks. BACKGROUND: Clefts of the orofacial region are among the most common congenital facial defects. The clinical presentation is usually that of a lateral cleft of the lip through the philtrum with or without extension through the palatal shelves. However, atypical forms of clefts with lip involvement also occur in a variety of patterns, some of which are embryologically predictable; others are not. METHODS: An overview of the embryology, cause, and incidence of this diverse and interesting group of congenital orofacial clefts is presented. RESULTS: Clefts involving the lateral upper lip; median upper lip; and oblique facial, lateral facial, and median mandibular regions are reviewed. CONCLUSIONS: This review of orofacial malformations describes clefting anomalies that emanate from the mouth and lips. As the causes of orofacial clefts are better understood, it is becoming clear that a complex interplay between genetic and environmental variables causes these clefts. Future study of orofacial clefts will require increasingly sophisticated methods of elucidating these subtle interactions.

Abnormalities, Multiple↗

PubMed2005

"Keystone" approach for intracranial nasofrontal dermoid sinuses.

Nasofrontal dermoid sinus tracts that extend intracranially through the foramen cecum or ethmoid can be difficult to completely resect. Complete extirpation of nasofrontal dermoid sinus cysts is essential for effective treatment of this problem to minimize the chance of recurrence. The authors describe a new technique based on parasagittal osteotomies through the supraorbital bar, or bandeau, that ensures that the resection of the nasofrontal dermoid sinus cysts is complete. This technique also limits the size of the external nasal incision and enhances the surgeon's exposure of the anterior cranial base for resection of intradural extension. This approach also enhances exposure for the direct repair of the dura and the cranial vault.

Child↗

PubMed2004

Resorbable PLLA-PGA plate and screw fixation in pediatric craniofacial surgery: clinical experience in 1883 patients.

The need to provide rigid bony fixation in the surgical treatment of craniofacial deformities has inspired an on-going evolution of surgical innovations and implants. Because of the young age of many treated craniosynostosis patients and the unique pattern of cranial vault growth, the extensive implantation of metal devices is potentially problematic. The use of resorbable plate and screw devices offers all of the benefits of rigid fixation without many of their potential risks. Since the introduction of resorbable plate and screw devices in 1996, tens of thousands of craniofacial patients have received implants, but long-term results from a large series have yet to be reported. A combined prospective and retrospective analysis was done on 1883 craniosynostosis patients under 2 years of age treated by 12 surgeons from seven different geographic locations over a 5-year period who used the same type of resorbable bone fixation devices (poly-L-lacticpolyglycolic copolymer). Specifically, the incidence of postoperative infection, fixation device failure, occurrence of delayed foreign-body reactions, and the need for reoperation resulting from device-related problems were determined. Technical difficulties and trends in device use were also noted. From this series, significant infectious complications occurred in 0.2 percent, device instability primarily resulting from postoperative trauma occurred in 0.3 percent, and self-limiting local foreign-body reactions occurred in 0.7 percent of the treated patients. The overall reoperation rate attributable to identifiable device-related problems was 0.3 percent. Improved bony stability was gained by using the longest plate geometries/configurations possible and bone grafting any significant gaps across plated areas that were structurally important. The specific types of plates and screws used evolved over the study period from simple plates, meshes, and threaded screws to application-specific plates and threadless push screws whose use varied among the involved surgeons. This report documents the safety and long-term value of the use of resorbable (LactoSorb) plate and screw fixation in pediatric craniofacial surgery in the infant and young child. Device-related complications requiring reoperation occurred in less than 0.5 percent of the implanted patients, which is less frequent than is reported for metallic bone fixation. Resorbable bone fixation for the rapidly growing cranial vault has fewer potential complications than the traditional use of metal plates, screws, and wires.

Absorbable Implants↗

PubMed2004

"Cat's cradle" midfacial fixation in distraction osteogenesis after Le Fort III osteotomy.

Distraction osteogenesis has provided a powerful technique for the treatment of severe midfacial hypoplasia. Skeletal fixation is a critical component of successful distraction osteogenesis. This is a report on the development of a new approach to bone fixation for distraction osteogenesis of the midface, based on circumferential suspension of the entire midfacial skeleton using surgical wires placed through the soft palate. This technique offers the advantages of (1) complete control of the attitude of the midface in terms of a precise dispersion of forces that can determine the desired pitch, yaw, and roll of this skeletal complex during the active phase of distraction, (2) being compatible with young children in the deciduous dentition stage because it obviates the need for rigid fixation devices on the maxillary lateral walls in the proximity of numerous dental follicles of the unerupted adult dentition, (3) actually serving as the instrument for posterior maxillary "lift" in cases of skeletal open bite malocclusions (frequently seen in the craniosynostoses), thereby allowing the clinician to determine the final occlusal and palatal planes and simultaneously close the open bite. An illustrative case of a 5(1/2)-year-old girl with Apert syndrome is presented wherein her ventilatory obstruction and ocular proptosis were significantly improved.

Acrocephalosyndactylia↗

PubMed2003

Sentinel lymph node biopsy in children and adolescents with malignant melanoma.

BACKGROUND/PURPOSE: Sentinel lymph node biopsy (SLNB) provides valuable staging information for adult patients presenting with clinically localized cutaneous melanoma. There are little data pertaining to the use of SLNB in the pediatric melanoma population. The objective of this study is to investigate the use of SLNB in the pediatric population, focusing on its diagnostic and therapeutic implications. METHODS: Retrospective identification was made of patients 18 years or younger who underwent sentinel lymph node biopsy for clinically localized melanoma at Indiana University Medical Center between 1994 and 2001. Patient demographics, primary tumor thickness, location of primary tumor, presence of tumor ulceration, number of lymph nodes removed, pathology of examined nodes, and number of lymph nodes involved with tumor were recorded. Disease status and dates of last clinical contact were determined. RESULTS: Twelve patients, 18 years or younger, were identified. Mean age of the study population was 14.1 years (range, 4 to 18). Mean tumor thickness was 1.65 mm (range, 0.36 to 4.7 mm). Three patients (25%) had positive sentinel lymph node biopsies. All 3 patients underwent completion lymph node dissection (CLND). One patient had micrometastatic disease detected on CLND; he had recurrence 6.1 months later and died 7.5 months after his SLND/CLND. At a median follow-up of 11.7 months, the remaining 11 patients had not experienced recurrence. There were no complications related to the SLNB procedure. CONCLUSIONS: The minimally invasive surgical approach and limited complications associated with SLNB make this procedure a useful aid in assisting the physician in making therapeutic decisions in the pediatric melanoma patient.

Adolescent↗

PubMed2002

Hydroxyapatite.

Explore the source record for details and available documents.

Bone Cements↗

PubMed2002

Midface distraction following Le Fort III and monobloc osteotomies: problems and solutions.

Distraction osteogenesis has been used increasingly for midfacial advancement in patients with syndromic craniosynostosis and in severe developmental hypoplasia of the midface. In these patients, the degree of advancement required is often so great that restriction of the adjacent soft tissues may preclude stable advancement in one stage. Whereas distraction is an ideal solution by which to gradually lengthen both the bones and the soft tissues, potential problems remain in translating the distraction forces to the midface. In these patients, severe developmental hypoplasia may be associated with weak union between the zygoma and the maxilla, increasing the chance of zygomaticomaxillary dysjunction when using internal devices that translate distraction force to the maxilla through the zygoma. Eight cases are reported in which either internal or external distraction systems were used for midface advancement following Le Fort III (n = 7) or monobloc (n = 1) osteotomies. Cases of patients in whom hypoplasia at the zygomaticomaxillary junction altered or impaired plans for midface distraction were reported from three host institutions. Seven patients had midface hypoplasia associated with syndromic craniosynostosis, and one patient had severe developmental midface hypoplasia. The distraction protocol was modified to successfully complete midface advancement in light of weakness at the zygomaticomaxillary junction in seven patients. Modifications included change from an internal to an external distraction system in two patients, rigid fixation and bone graft stabilization of the midface in one patient, and plate stabilization of a fractured or unstable zygomaticomaxillary junction followed by resumption of internal distraction in four patients. Previous infection and bone loss involving both malar complexes precluded one patient from being a candidate for an internal distraction system. Using a problem-based approach, successful advancement of the midface ranging from 9 to 26 mm at the occlusal level as measured by preoperative and postoperative cephalograms was undergone by all patients. Advantages and disadvantages of the respective distraction systems are reviewed to better understand unique patient characteristics leading to the successful use of these devices for correction of severe midface hypoplasia.

Child↗

PubMed2002

The impact of early palatal obturation on consonant development in babies with unrepaired cleft palate.

OBJECTIVE: The purpose of this investigation was to determine whether palatal obturators enhance consonant development during babbling for babies with unrepaired cleft palate. PARTICIPANTS: Fourteen babies with cleft palate who had worn anterior palatal obturators prior to palatal surgery were matched to 14 unobturated babies according to cleft type, sex, and age at time of presurgical evaluation. MAIN OUTCOME MEASURES: Spontaneous vocalizations of the obturated and unobturated groups were compared to determine whether differences were evident in size of consonant inventory as well as place and manner of consonant production. RESULTS: Paired t tests revealed no significant differences between the groups in size of consonant inventory or place and manner of consonant production. There was a trend for babies in the obturated group to produce more glottal consonants. CONCLUSIONS: In general, the findings of this study suggested that palatal obturators do not appear to facilitate production of anterior palatal consonants during babbling.

Acoustic Impedance Tests↗