Thomas Hierl | Leipzig University (Universität Leipzig) (original) (raw)
Papers by Thomas Hierl
International Congress Series, 2004
A clinical case in maxillofacial surgery is presented, where a congenital hypoplasia of the midfa... more A clinical case in maxillofacial surgery is presented, where a congenital hypoplasia of the midface with apparent dental malocclusion was to be treated. A 3D osteotomy planning on a polygonal skull model has been performed for different types of osteotomies, followed by a maxillary advancement under consideration of the implications on the facial soft tissue deformation, using a volumetric finite element approach. The simulation results of isotropic, homogeneous as well as inhomogeneous tissue models using a linear elastic modeling approach are quantitatively evaluated with the help of postoperative CT data. D 2004 Published by Elsevier B.V.
Oral and Maxillofacial Surgery, 2003
Fragestellung. Für Patienten mit ausgeprägter Mittelgesichtsrücklage und -atrophie stellt die Dis... more Fragestellung. Für Patienten mit ausgeprägter Mittelgesichtsrücklage und -atrophie stellt die Distraktionsosteogenese eine Therapiealternative dar. Anhand eines größeren Patientenguts und einem bis zu 4-jährigen Beobachtungszeitraum soll dieses Verfahren evaluiert werden. Patienten. Im Zeitraum von Mai 1998–Mai 2002 wurden 38 Patienten mit einem extraoralen Distraktor (RED) behandelt. Es handelte sich dabei um 13 Frauen und 25 Männer im Alter von 6–65 Jahren. Bei 32 Patienten lag eine angeborene Spaltbildung vor, 1 Patientin litt an einem Morbus Crouzon. In insgesamt 28 Fällen war eine Velopharyngoplastik vorhanden, 9 Patienten waren im Oberkiefer ganz oder nahezu zahnlos. Untersucht wurden das Rezidivverhalten anhand von Fernröntgenseitbildaufnahmen, die Veränderung des velopharyngealen Abschlusses und die Häufigkeit der behandlungsassoziierten Komplikationen. Ergebnisse. In allen Fällen konnte die beabsichtigte Mittelgesichtsvorverlagerung erzielt werden (9–31 mm; durchschnittlich 17 mm). Während der Distraktionsphase mussten 7 Patienten (18%) aufgrund von Komplikationen reoperiert werden. In 2 Fällen erfolgte nach Konsolidierung der Distraktion eine LeFort-I-Osteotomie zur Feineinstellung der Okklusion. In 21% der Fälle konnte eine Verschlechterung und in 8% eine Verbesserung der velopharyngealen Funktion festgestellt werden. Das Rezidivverhalten entsprach prozentual dem konventioneller LeFort-I-Osteotomien bei Spaltpatienten (etwa 15–20%), wobei die meisten Veränderungen innerhalb der ersten 6 Monate nach der Distraktion erfolgten. Schlussfolgerungen. Die Distraktionsosteogenese ist eine sichere Methode, um auch große sagittale Diskrepanzen bei schwierigen Weichgewebeverhältnissen zu bewältigen. Aufgrund der technisch anspruchsvollen Methode und der in der Regel schwierigen Patientensituation ist von einer gegenüber konventionellen Dysgnathieeingriffen erhöhten Komplikationsrate auszugehen. Patients. Between May 1998 and May 2002, 38 patients suffering from severe midfacial retrusion and atrophy were treated by way of midfacial distraction osteogenesis. Diagnoses included cleft lip and palate (32 patients) and one case of Crouzon’s disease. Ages ranged from 6–65 years. A total of 28 patients presented a velopharyngeal flap and nine patients were almost or fully edentulous. Using an extraoral halo device, distraction was performed after a subtotal Le Fort-I/II/III or modified quadrangular osteotomy. Results. Distraction ranged from 9 to 31 mm (17 mm average). Following the primary operation, seven patients underwent a second intervention due to problems with the procedure or the device. Two patients needed a secondary Le Fort-I-osteotomy. With respect to velopharyngeal insufficiency, 21% showed a deterioration and 8% an improvement. Postoperatively, a decrease of 15–20% in the attained sagittal advancement was seen during the first 6 months. This was attributed to relapses and postoperative orthodontics. Thereafter skeletal stability was maintained. Conclusion. Distraction osteogenesis of the midface can be the method of choice in severe midfacial retrusion. Due to the difficult patient situation and the technical intricacies a higher complication rate has to be accepted than for conventional dysgnathia operations.
International Journal of Oral and Maxillofacial Surgery, 2001
Correct placement of intraoral devices for mandibular distraction osteogenesis is important to ac... more Correct placement of intraoral devices for mandibular distraction osteogenesis is important to achieve the ideal vector of distraction. As visual inspection and intraoperative management in the inferior mandibular border or at the posterior ascending ramus is impaired, an endoscopically assisted method is presented. Since the introduction of this new technique operation time and ease have been significantly improved.
Cleft Palate-craniofacial Journal, 1999
This report introduces the possibilities of callus distraction in the extremely atrophied, edentu... more This report introduces the possibilities of callus distraction in the extremely atrophied, edentulous midface in a cleft lip and palate patient. After a subtotal Le Fort II osteotomy, tension wires were fixed to the zygomatic buttresses and frontal sinus walls by way of titanium miniplates and mesh and connected to a rigid external distractor. Then distraction of the whole midface (1 mm/d) was performed. Even in severe atrophy a distraction of the maxilla of 20 mm was possible. Stability has been shown for more than 5 months. Rigid external midfacial distraction may be used in difficult cases for the correction of sagittal discrepancies where conventional orthognathic surgery is likely to be insufficient. Further investigations will concentrate on the long-term outcome.
Journal of Craniofacial Surgery, 2009
In contrast to the multitude of investigations regarding aesthetic changes in nasal surgery, few ... more In contrast to the multitude of investigations regarding aesthetic changes in nasal surgery, few data are available concerning nasal function. This is especially important for cleft patients with a compromised nasal respiration.
Plastic and Reconstructive Surgery, 2001
Journal of Cranio-maxillofacial Surgery, 2006
Review: In the year 1994 the former GDR cleft centre was integrated into the Department of Maxill... more Review: In the year 1994 the former GDR cleft centre was integrated into the Department of Maxillofacial and Facial Plastic Surgery of the University of Leipzig. The treatment scheme of functional surgery according to DELAIRE was introduced to this new cleft and craniofacial centre at the University of Leipzig. The interdisciplinary team of specialists meets twice a week during a cleft clinic and takes care of about 900 out-patients per year. In the last decade an average of 40-50 new patients (infants) were admitted for in-patient primary surgery. Lip repair with reconstruction of the perinasal and perioral muscle rings is performed in combination with a primary rhinoplasty at the age of 5-6 months. Hard and soft palate are closed in a one stage procedure before the end of the first year of life. The results at the age of 12 years demonstrate good facial proportions and speaking abilities in far more than 90% of all cases. This functionally based treatment of clefts of lip, alveolus and palate achieves a good outcome with a low number of operative procedures.
Oral and Maxillofacial Surgery, 2003
Fragestellung Im Rahmen einer prospektiven Studie sollten nasenfunktionelle und ästhetische Verän... more Fragestellung Im Rahmen einer prospektiven Studie sollten nasenfunktionelle und ästhetische Veränderungen und deren Beziehung zueinander untersucht werden. Patienten Im Zeitraum von Juni 1996 bis November 2000 wurden bei 60 Spaltpatienten Nasenkorrekturen durchgeführt. Es handelte sich dabei um 27 Frauen und 33 Männer im Alter von 7–50 Jahren. Bei 37 Patienten lag eine doppelseitige, bei 23 Patienten eine einseitige LKG-Spalte vor. Als objektivierbare Untersuchungsmethoden der respiratorischen Funktion der Nase dienten die aktive anteriore Rhinomanometrie, die Rhinoresistometrie und die akustische Rhinometrie, die jeweils prä- und postoperativ ohne und mit abschwellenden Nasentropfen durchgeführt wurden. Weiterhin wurden prä- und postoperative standardisierte Fotoaufnahmen von lateral, en face und kaudal ausgewertet. Ergebnisse Im Vergleich zu Normalkollektiven lagen präoperativ sowohl eine ausgeprägte spaltbedingte Nasendysplasie als auch eine deutliche Nasenatmungsbehinderung vor. Hinsichtlich der ästhetischen Veränderungen zeigte sich u. a. eine signifikante Verbesserung der Nasenprojektion, bei einseitigen LKG-Spalten darüber hinaus eine Zunahme der Symmetrie beider Nasenhälften. In Bezug auf nasenfunktionelle Änderungen waren bei einseitigen Spalten eine Zunahme des nasalen Flows nach Gabe von abschwellenden Nasentropfen sowie des hydraulischen Durchmessers festzustellen. Demgegenüber zeigte sich in der Gruppe der doppelseitigen Spaltpatienten eine tendenzielle Verschlechterung. Eine Beziehung zwischen äußerer Form und Funktion bzw. Veränderung von Form und Funktion konnte nicht gefunden werden. Schlussfolgerungen Während ästhetische Verbesserungen regelmäßig erzielt werden konnten, waren die nasenfunktionellen Befunde prä- und postoperativ nicht zufriedenstellend. Objektivierbare Untersuchungsmethoden sind für die Evaluation der Nasenatmung und zur Bewertung der eigenen Ergebnisse notwendig. Between June 1996 and November 2000 60 patients suffering from severe nasal dysplasia due to cleft lip and palate (CLP) underwent corrective nasal surgery. Diagnoses included 37 cases of unilateral CLP and 23 cases of bilateral CLP. Age ranged from 7 to 50 years. To assess functional outcome three different methods were used pre- and postoperatively with and without nasal decongestion: active anterior rhinomanometry, rhinoresistometry, and acoustic rhinometry. For the measurement of esthetic changes frontal, lateral, and caudal photographs were analyzed. Compared to a non-cleft population esthetic and functional impairment was evident preoperatively. Postoperatively a statistically significant improvement in nasal projection and configuration was seen. Concerning nasal respiration an improvement in nasal flow and hydraulic diameter was noted in the unilateral CLP group only, whereas a statistically nonsignificant average deterioration was found in the bilateral CLP group. No correlation existed between external nasal form or the change in nasal appearance and nasal function. Whereas the esthetic outcome of nasal surgery is covered by way of photo-analysis in many centers, a distinct lack of measuring the effects on nasal function can be stated. Without using objective methods, however, no data for improving surgical procedures and for internal quality control are at hand.
Journal of Cranio-maxillofacial Surgery, 1997
As the obstructive sleep apnoea syndrome (OSAS) can be aggravated or even caused by craniofacial ... more As the obstructive sleep apnoea syndrome (OSAS) can be aggravated or even caused by craniofacial anomalies, the need for interdisciplinary diagnostics and treatment is obvious. Thus 152 patients suffering from OSAS were referred to the Department of Oral and MaxiUofacial Surgery by the Sleep Laboratory of the University from July 1994 to January 1996. The data gained from clinical examination, cephalometry and polysomnography were tested in a principal component analysis to differentiate between several types of patients.
Journal of Computing and Information Technology, 2006
In the reconstruction of complex craniofacial malformations CAD-CAM procedures could help generat... more In the reconstruction of complex craniofacial malformations CAD-CAM procedures could help generating alloplastic implants to achieve almost optimal esthetic results. Complementary to the existing CAD-CAM techniques in the cranial vault region or modeling procedures in unilateral defects, these techniques are introduced to bilaterally affected skulls in esthetic reconstructive surgery. Surgery could thus become less invasive and results more predictable. A tool chain is shown to generate such implants on scientific basis. 3D cephalometric analysis is performed and the implants are designed according to the individual pathology. Besides the planning of implants on the basis of 3D-landmarks, future implant design is supposed to be performed with the help of a craniofacial library taken from CT-scans of unaffected skulls.
International Congress Series, 2004
A clinical case in maxillofacial surgery is presented, where a congenital hypoplasia of the midfa... more A clinical case in maxillofacial surgery is presented, where a congenital hypoplasia of the midface with apparent dental malocclusion was to be treated. A 3D osteotomy planning on a polygonal skull model has been performed for different types of osteotomies, followed by a maxillary advancement under consideration of the implications on the facial soft tissue deformation, using a volumetric finite element approach. The simulation results of isotropic, homogeneous as well as inhomogeneous tissue models using a linear elastic modeling approach are quantitatively evaluated with the help of postoperative CT data. D 2004 Published by Elsevier B.V.
Oral and Maxillofacial Surgery, 2003
Fragestellung. Für Patienten mit ausgeprägter Mittelgesichtsrücklage und -atrophie stellt die Dis... more Fragestellung. Für Patienten mit ausgeprägter Mittelgesichtsrücklage und -atrophie stellt die Distraktionsosteogenese eine Therapiealternative dar. Anhand eines größeren Patientenguts und einem bis zu 4-jährigen Beobachtungszeitraum soll dieses Verfahren evaluiert werden. Patienten. Im Zeitraum von Mai 1998–Mai 2002 wurden 38 Patienten mit einem extraoralen Distraktor (RED) behandelt. Es handelte sich dabei um 13 Frauen und 25 Männer im Alter von 6–65 Jahren. Bei 32 Patienten lag eine angeborene Spaltbildung vor, 1 Patientin litt an einem Morbus Crouzon. In insgesamt 28 Fällen war eine Velopharyngoplastik vorhanden, 9 Patienten waren im Oberkiefer ganz oder nahezu zahnlos. Untersucht wurden das Rezidivverhalten anhand von Fernröntgenseitbildaufnahmen, die Veränderung des velopharyngealen Abschlusses und die Häufigkeit der behandlungsassoziierten Komplikationen. Ergebnisse. In allen Fällen konnte die beabsichtigte Mittelgesichtsvorverlagerung erzielt werden (9–31 mm; durchschnittlich 17 mm). Während der Distraktionsphase mussten 7 Patienten (18%) aufgrund von Komplikationen reoperiert werden. In 2 Fällen erfolgte nach Konsolidierung der Distraktion eine LeFort-I-Osteotomie zur Feineinstellung der Okklusion. In 21% der Fälle konnte eine Verschlechterung und in 8% eine Verbesserung der velopharyngealen Funktion festgestellt werden. Das Rezidivverhalten entsprach prozentual dem konventioneller LeFort-I-Osteotomien bei Spaltpatienten (etwa 15–20%), wobei die meisten Veränderungen innerhalb der ersten 6 Monate nach der Distraktion erfolgten. Schlussfolgerungen. Die Distraktionsosteogenese ist eine sichere Methode, um auch große sagittale Diskrepanzen bei schwierigen Weichgewebeverhältnissen zu bewältigen. Aufgrund der technisch anspruchsvollen Methode und der in der Regel schwierigen Patientensituation ist von einer gegenüber konventionellen Dysgnathieeingriffen erhöhten Komplikationsrate auszugehen. Patients. Between May 1998 and May 2002, 38 patients suffering from severe midfacial retrusion and atrophy were treated by way of midfacial distraction osteogenesis. Diagnoses included cleft lip and palate (32 patients) and one case of Crouzon’s disease. Ages ranged from 6–65 years. A total of 28 patients presented a velopharyngeal flap and nine patients were almost or fully edentulous. Using an extraoral halo device, distraction was performed after a subtotal Le Fort-I/II/III or modified quadrangular osteotomy. Results. Distraction ranged from 9 to 31 mm (17 mm average). Following the primary operation, seven patients underwent a second intervention due to problems with the procedure or the device. Two patients needed a secondary Le Fort-I-osteotomy. With respect to velopharyngeal insufficiency, 21% showed a deterioration and 8% an improvement. Postoperatively, a decrease of 15–20% in the attained sagittal advancement was seen during the first 6 months. This was attributed to relapses and postoperative orthodontics. Thereafter skeletal stability was maintained. Conclusion. Distraction osteogenesis of the midface can be the method of choice in severe midfacial retrusion. Due to the difficult patient situation and the technical intricacies a higher complication rate has to be accepted than for conventional dysgnathia operations.
International Journal of Oral and Maxillofacial Surgery, 2001
Correct placement of intraoral devices for mandibular distraction osteogenesis is important to ac... more Correct placement of intraoral devices for mandibular distraction osteogenesis is important to achieve the ideal vector of distraction. As visual inspection and intraoperative management in the inferior mandibular border or at the posterior ascending ramus is impaired, an endoscopically assisted method is presented. Since the introduction of this new technique operation time and ease have been significantly improved.
Cleft Palate-craniofacial Journal, 1999
This report introduces the possibilities of callus distraction in the extremely atrophied, edentu... more This report introduces the possibilities of callus distraction in the extremely atrophied, edentulous midface in a cleft lip and palate patient. After a subtotal Le Fort II osteotomy, tension wires were fixed to the zygomatic buttresses and frontal sinus walls by way of titanium miniplates and mesh and connected to a rigid external distractor. Then distraction of the whole midface (1 mm/d) was performed. Even in severe atrophy a distraction of the maxilla of 20 mm was possible. Stability has been shown for more than 5 months. Rigid external midfacial distraction may be used in difficult cases for the correction of sagittal discrepancies where conventional orthognathic surgery is likely to be insufficient. Further investigations will concentrate on the long-term outcome.
Journal of Craniofacial Surgery, 2009
In contrast to the multitude of investigations regarding aesthetic changes in nasal surgery, few ... more In contrast to the multitude of investigations regarding aesthetic changes in nasal surgery, few data are available concerning nasal function. This is especially important for cleft patients with a compromised nasal respiration.
Plastic and Reconstructive Surgery, 2001
Journal of Cranio-maxillofacial Surgery, 2006
Review: In the year 1994 the former GDR cleft centre was integrated into the Department of Maxill... more Review: In the year 1994 the former GDR cleft centre was integrated into the Department of Maxillofacial and Facial Plastic Surgery of the University of Leipzig. The treatment scheme of functional surgery according to DELAIRE was introduced to this new cleft and craniofacial centre at the University of Leipzig. The interdisciplinary team of specialists meets twice a week during a cleft clinic and takes care of about 900 out-patients per year. In the last decade an average of 40-50 new patients (infants) were admitted for in-patient primary surgery. Lip repair with reconstruction of the perinasal and perioral muscle rings is performed in combination with a primary rhinoplasty at the age of 5-6 months. Hard and soft palate are closed in a one stage procedure before the end of the first year of life. The results at the age of 12 years demonstrate good facial proportions and speaking abilities in far more than 90% of all cases. This functionally based treatment of clefts of lip, alveolus and palate achieves a good outcome with a low number of operative procedures.
Oral and Maxillofacial Surgery, 2003
Fragestellung Im Rahmen einer prospektiven Studie sollten nasenfunktionelle und ästhetische Verän... more Fragestellung Im Rahmen einer prospektiven Studie sollten nasenfunktionelle und ästhetische Veränderungen und deren Beziehung zueinander untersucht werden. Patienten Im Zeitraum von Juni 1996 bis November 2000 wurden bei 60 Spaltpatienten Nasenkorrekturen durchgeführt. Es handelte sich dabei um 27 Frauen und 33 Männer im Alter von 7–50 Jahren. Bei 37 Patienten lag eine doppelseitige, bei 23 Patienten eine einseitige LKG-Spalte vor. Als objektivierbare Untersuchungsmethoden der respiratorischen Funktion der Nase dienten die aktive anteriore Rhinomanometrie, die Rhinoresistometrie und die akustische Rhinometrie, die jeweils prä- und postoperativ ohne und mit abschwellenden Nasentropfen durchgeführt wurden. Weiterhin wurden prä- und postoperative standardisierte Fotoaufnahmen von lateral, en face und kaudal ausgewertet. Ergebnisse Im Vergleich zu Normalkollektiven lagen präoperativ sowohl eine ausgeprägte spaltbedingte Nasendysplasie als auch eine deutliche Nasenatmungsbehinderung vor. Hinsichtlich der ästhetischen Veränderungen zeigte sich u. a. eine signifikante Verbesserung der Nasenprojektion, bei einseitigen LKG-Spalten darüber hinaus eine Zunahme der Symmetrie beider Nasenhälften. In Bezug auf nasenfunktionelle Änderungen waren bei einseitigen Spalten eine Zunahme des nasalen Flows nach Gabe von abschwellenden Nasentropfen sowie des hydraulischen Durchmessers festzustellen. Demgegenüber zeigte sich in der Gruppe der doppelseitigen Spaltpatienten eine tendenzielle Verschlechterung. Eine Beziehung zwischen äußerer Form und Funktion bzw. Veränderung von Form und Funktion konnte nicht gefunden werden. Schlussfolgerungen Während ästhetische Verbesserungen regelmäßig erzielt werden konnten, waren die nasenfunktionellen Befunde prä- und postoperativ nicht zufriedenstellend. Objektivierbare Untersuchungsmethoden sind für die Evaluation der Nasenatmung und zur Bewertung der eigenen Ergebnisse notwendig. Between June 1996 and November 2000 60 patients suffering from severe nasal dysplasia due to cleft lip and palate (CLP) underwent corrective nasal surgery. Diagnoses included 37 cases of unilateral CLP and 23 cases of bilateral CLP. Age ranged from 7 to 50 years. To assess functional outcome three different methods were used pre- and postoperatively with and without nasal decongestion: active anterior rhinomanometry, rhinoresistometry, and acoustic rhinometry. For the measurement of esthetic changes frontal, lateral, and caudal photographs were analyzed. Compared to a non-cleft population esthetic and functional impairment was evident preoperatively. Postoperatively a statistically significant improvement in nasal projection and configuration was seen. Concerning nasal respiration an improvement in nasal flow and hydraulic diameter was noted in the unilateral CLP group only, whereas a statistically nonsignificant average deterioration was found in the bilateral CLP group. No correlation existed between external nasal form or the change in nasal appearance and nasal function. Whereas the esthetic outcome of nasal surgery is covered by way of photo-analysis in many centers, a distinct lack of measuring the effects on nasal function can be stated. Without using objective methods, however, no data for improving surgical procedures and for internal quality control are at hand.
Journal of Cranio-maxillofacial Surgery, 1997
As the obstructive sleep apnoea syndrome (OSAS) can be aggravated or even caused by craniofacial ... more As the obstructive sleep apnoea syndrome (OSAS) can be aggravated or even caused by craniofacial anomalies, the need for interdisciplinary diagnostics and treatment is obvious. Thus 152 patients suffering from OSAS were referred to the Department of Oral and MaxiUofacial Surgery by the Sleep Laboratory of the University from July 1994 to January 1996. The data gained from clinical examination, cephalometry and polysomnography were tested in a principal component analysis to differentiate between several types of patients.
Journal of Computing and Information Technology, 2006
In the reconstruction of complex craniofacial malformations CAD-CAM procedures could help generat... more In the reconstruction of complex craniofacial malformations CAD-CAM procedures could help generating alloplastic implants to achieve almost optimal esthetic results. Complementary to the existing CAD-CAM techniques in the cranial vault region or modeling procedures in unilateral defects, these techniques are introduced to bilaterally affected skulls in esthetic reconstructive surgery. Surgery could thus become less invasive and results more predictable. A tool chain is shown to generate such implants on scientific basis. 3D cephalometric analysis is performed and the implants are designed according to the individual pathology. Besides the planning of implants on the basis of 3D-landmarks, future implant design is supposed to be performed with the help of a craniofacial library taken from CT-scans of unaffected skulls.