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Biomedical subjects

H P Howaldt

Publications and source records attributed to H P Howaldt.

At least 19 recordsLinked to original sources
PubMed2002

[CleftData. Program for minimal documentation of lip-jaw-palate clefts].

BACKGROUND: The aim of the German Study Group on Cleft Lip and Palate-Craniofacial Deformities is to develop a precise system for documentation of cleft lip and palate patients which is suitable for use in PC-databases. DOCUMENTATION: In cooperation with the medical disciplines involved in the therapy such as otolaryngology, oral and maxillofacial surgery, orthodontics and speech therapy a system of documentation was developed with regard to the international classification of diseases (ICD) and the operating procedures system (OPS). Malformations are classified with the LAHS coding system. In addition to this concept of minimal documentation photographic images in standardized projections are stored. Furthermore, each operative procedure is documented by its date and the anatomic region of malformation treated without details of operative methods or descriptions of other procedures. SOFTWARE: On behalf of the German Study Group on Cleft Lip and Palate a software to meet these purposes was developed called CleftData. Based on a relational Access database it is equipped with SQL connectivity enabling its use on all hard- and software-systems.

Cleft Lip↗
PubMed2001

Standardized evaluation and documentation of findings in patients with craniosynostosis.

Surgical correction of craniosynostosis is usually performed according to standard procedures. However, a standard for clinical examination and report of findings for patients with craniosynostosis does not exist as yet. To compare findings from different hospitals, a documentation system was developed by a national craniosynostosis group. This system comprises a two-page document, clinical photographs, radiographs, CT scans, anthropometric measurements and molecular genetic findings. Data from craniosynostosis patients collected from participating hospitals are stored in a database, which facilitates online access.The documentation system was developed in cooperation with the group during 3 years since 1996. It was evaluated as being practicable and reliable and enables a comparability of findings reported in different hospitals. Molecular genetic analysis was found to support the investigation of patients with craniosynostosis and should therefore be integrated in the clinical evaluation. Copyright 2001 European Association for Cranio-Maxillofacial Surgery.

Journal Article↗
PubMed2001

Surgical correction of scaphocephaly: experiences with a new procedure and follow-up investigations.

Introduction: Simple resection of the sagittal suture and the use of alloplastic material or extensive skull resections have long been proven to be unsatisfactory in the treatment of sagittal synostosis. In contrast to these experiences, the immediate correction of skull shape seems to yield the best results without significant morbidity. Patients: Thirty-six scaphocephalic infants with an average age of 6.5 (3.5-14) months underwent operation by our craniofacial team since 1994. Methods: Wide resection of the sagittal suture was used in combination with a bone-strip resection along the coronal and lambdoid sutures. Occasionally partial resection and reshaping of the frontal or occipital bone was necessary to correct an extremely bulging skull. The cranial growth and shape was monitored by anthropometric skull measurements in the last 20 patients. Results: Except in two cases, in which the dura mater was minimally injured intraoperatively, no complications occurred in any patient. Craniofacial oedema always occurred but disappeared after 72 h. The immediate correction of the skull shape was successful in all cases and was completed within 6 months postoperatively. There was no iatrogenic bone defect one year after surgery. Postoperative skull shape and growth was normal. Conclusion: These procedures seem to be effective in the treatment of scaphocephalus. Further normalization of skull shape is achieved by unrestricted postoperative brain growth. Copyright 2001 European Association for Cranio-Maxillofacial Surgery.

Journal Article↗
PubMed2001

The Giessen-Mainz-Frankfurt procedure: a new method for complex pelvic reconstruction for bladder exstrophy.

PURPOSE: In bladder exstrophy primary reconstruction remains the gold standard worldwide. Despite various types of osteotomies the permanent correction of pubic diastasis remains a challenge. In maxillofacial surgery callus distraction is a routine treatment for hypoplastic mandibles. Originally described by Ilizarov, this method provides stable and true bone lengthening after gradual distraction of an osteotomy site as long as the periosteum remains intact. In cooperation with the departments of maxillofacial surgery and orthopedics we used this technique to correct pubic diastasis and facilitate phallic reconstruction in a 4 1/2-year-old boy with bladder exstrophy who had previously undergone continent diversion. MATERIALS AND METHODS: Three-dimensional computerized tomography was used to create a stereolithography model and mock surgery was performed. Based on this model bilateral osteotomies of the superior and inferior segments of the pubic bones were done, preserving the periosteum. Pins were inserted and a multidirectional external fixation device was mounted. Distraction was started on day 5 postoperatively. The distraction rate was 1 mm. daily and immobilization time was 28 days. The distraction progress was monitored by sonography. The device was removed 6 weeks postoperatively. RESULTS: Radiography of the pelvis 2 years postoperatively revealed that the distance between the pubic bones had decreased from 6 to 3 cm. (50%). Simultaneously the slanting angle normalized from 24 to 35 degrees due to upward rotation of the inferior pubic rami. Mineralization in the newly formed bones was excellent. Visible penile length had increased significantly. CONCLUSIONS: To our knowledge we describe the first use of the basic Ilizarov principle of callus distraction for permanent complex pelvic reconstruction for bladder exstrophy in a 4 1/2-year-old boy. After subperiostial osteotomies approximation of the symphysis and rotation of the inferior pubic rami were achieved with a device commonly used in maxillofacial surgery. Approximation of 1 mm. daily for 28 days resulted in significant penile lengthening. At a followup of 2 years there were stable pelvic ring reconstruction and normal mineralization of the newly formed bones. In contrast to the standard techniques of osteotomies for correcting pubic diastasis, the Giessen-Mainz-Frankfurt procedure provides true bone growth with a stable decrease in diastasis. Successful penile reconstruction was facilitated 1 year postoperatively. This method may also be useful in primary and secondary bladder reconstruction.

Bladder Exstrophy↗
PubMed2000

[Osteoplasty of extensive jaw defects by protected bone regeneration using large pore resorbable implant].

This study was performed to demonstrate a protected bone regeneration method using macroporous resorbable sheets for the treatment of extended lower and upper jaw defects. By applying mechanical protection of bony defects with, e.g. membranes or titanium mesh, soft tissue prolapse as well as pressure on bone transplants which contributes to partial resorption can be avoided. The use of a pressure-resistant, resorbable, macroporous sheet combines the advantage of protected bone regeneration and complete resorption of the implanted sheet. The macroporous structure facilitates capillary ingrowth from the surrounding soft tissue. The sheet is made of 70:30 Poly(L-co-DL)-lactate with thermoplastic character and can be used as a container for autologous spongiosa or other osteoinductive and -conductive bone graft substitutes. In a pilot study, seven patients with lower jaw defects resulting from large cysts or tumor resections, some affecting the continuity of the mandible, were treated with this method. Following a protocol, X-rays were obtained to document the bony regeneration. The positive experience with this pilot study encouraged a multicenter project involving five university hospitals and 50 patients. The application of resorbable sheets in combination with transplantation of mersilized autologous spongiosa is currently being investigated. In future studies, fillings of sheets with osteoconductive and -inductive materials are planned.

Aged↗
PubMed2000

[Results of the DOSAK tumor register].

The German-Swiss-Austrian Group on Maxillofacial Tumors (DOSAK) has been performing observational studies in oral cancer. Since 1989, approximately 1600 cases of tumor of the head and neck per years has been collected in a central tumor registry. The database consists of more than 16,000 patients from 71 clinics; almost two-thirds are primary cases of squamous cell carcinoma. The data show great differences in patho-anatomical findings, therapy concepts, and five-year survival rates among the hospitals.

Carcinoma, Squamous Cell↗
PubMed2000

Cephalometric assessment of sagittal jaw base relationship prior to orthognathic surgery: the role of anterior cranial base inclination.

In a cephalometric study, 71 presurgical lateral radiographs of patients suffering from malpositions of 1 or both jaws were analyzed to assess the influence of cranial base inclination on anteroposterior cephalometric angles. Angles SNA and SNB, as well as the angle between sella-nasion (SN) and Frankfort horizontal (FH), were measured. To verify the true sagittal position of the jaws, SNA and SNB were related to a corrected normal anterior cranial base inclination (mSNA, mSNB). Two geometric models were calculated and examined. The application of the first and second models for SNA and SNB resulted in different estimations of the sagittal jaw position in 46% and 38% of the presented patients, respectively. Linear regression analysis demonstrates that FH may not be substituted for SN as a reference line in anteroposterior measurements, but underlines that a correction with regard to anterior cranial base inclination is beneficial. According to the results of the second model, the most valuable reference line appears to be located approximately halfway between SN and FH. Considering the frequent coincidence of jaw malposition and cranial base dysmorphia, cranial base-related cephalometric parameters should be interpreted carefully.

Adolescent↗
PubMed1999

Application of ultrasound in callus distraction of the hypoplastic mandible: an additional method for the follow-up.

Mandibular callus distraction was performed on 14 patients. In addition to established radiological methods, sonography was performed to monitor the clinical progress. Ultrasound shows a precise picture of all interesting items in distraction treatment. Although the value of radiographs is not obsolete completely, sonography was found to be a meaningful supplement in the clinical monitoring of callus distraction. Furthermore the method is capable of early recognition of complications and it can reduce X-ray exposure.

Adolescent↗
PubMed1999

Proposal for modification of the TNM staging classification for cancer of the oral cavity. DOSAK.

AIM: The prognostic value of the TNM and pTNM classifications currently used for tumours of the oral cavity is unsatisfactory. A better classification should be aimed at as today's definition of T4 leads to overclassification of many tumours and today's definition of N3 results in too few lymph nodes in this group. Until 1987 the grade of fixation of lymph-nodes was part of the N-classification for oral cancer as it is currently used in the N-classification of breast cancer. METHODS: From 1987 to 1991 the DOSAK tumour registry has stored 1532 primary cases of cancer of the oral cavity from 23 hospitals. Crosstables were applied to outline the classification rule for clinical and histopathological T and N based on important factors (T: tumour diameter and thickness; N: lymph node diameter and grade of fixation; pT: histopathological tumour diameter and thickness; pN: number of lymph nodes involved by the tumour). A Cox model was calculated and combinations of similar prognostic estimates were summarized to the same clinical and histopathological T and N. It was aimed at separating categories and achieving equivalent clinical and histopathological T classifications and group frequencies. In a final step a clinical and histopathological stage grouping can be proposed. RESULTS: The gradation of the survival rates shows a marked separation between the T, N and stage categories. The distribution of T, N and stage categories was more uniform when applying the new classification.

Austria↗
PubMed1998

[Treatment of non-synostotic, pediatric skull deformities with dynamic head orthosis].

In all craniofacial deformities the differential diagnosis between synostotic and non-synostotic conditions must be made. While the first group is usually subject to intracranial surgical intervention, the treatment of non-synostotic deformities is the subject of controversial discussion. Often associated with premature birth, restrictive intrauterine environment or torticollis, these conditions; also defined as positional deformations, can lead to severe plagiocephalic head shapes. Dynamic orthotic cranioplasty is a conservative method of treating these deformities in early childhood by means of an individually fabricated orthotic head band. The principle is that dynamic pressure is applied to prominent parts while leaving space for growth in depressed areas. In accordance with this principle, various deformities can be addressed. Through clinical, anthropometric and radiographic evaluation it has been shown that dynamic orthotic cranioplasty can correct positional deformation of the cranial vault, skull base and upper face with no relapse following treatment. It must be emphasised that the method is simple, easy to handle and very effective when treatment starts within the first 6 months of life. Therefore, its potential should be recognised by paediatricians and craniofacial surgeons.

Cephalometry↗
PubMed1998

[Standardized ultrasound follow-up of callus distraction of the mandible].

Up to now the clinical follow-up in mandibular callus distraction was supported by radiologic methods, although low-mineralized structures are only insufficiently described by X-rays. Mandibular callus distraction was performed on 14 patients suffering from uni- or bilateral mandibular hypoplasia, using either intra- or extraoral devices. The clinical follow-up was supplemented by standardized sonographic investigations. With the exception of postoperative pin placement control, which was done by using X-rays, all interesting items of treatment could be visualized by sonography. We found a reliable correlation between sonographically measured distances and distances measured on the device. Due to early detection of complications, a premature ossification was detected in one case and an infection was diagnosed in another, using ultrasound. Sonography proved to enhance the possibilities of monitoring in mandibular callus distraction treatment and can be recommended in clinical routine.

Adolescent↗
PubMed1997

[Lateral orbitectomy for correction of endocrine ophthalmopathy].

Grave's disease is often associated with various symptoms summarized as endocrine orbitopathy. A surgical procedure is presented which reduces the exophthalmos by approximately 4.5 mm by resecting the caudal and lateral orbital wall through a subciliar incision. The surgical intervention regularly leads to an amelioration of the functional symptoms of endocrine orbitopathy, such as diplopia, corneal exposure and lid irregularities. In one case an acute reduction of vision on both eyes significantly ameliorated immediately after surgery. The operation described also improves the aesthetic appearance of the patients, who often suffer psychologic impairments associated with Grave's disease.

Decompression, Surgical↗
PubMed1996

Mandibular distraction osteogenesis as first step in the early treatment of severe dysgnathia in childhood.

The sole orthodontic treatment of severe dysgnathias in childhood often leads to unsatisfactory results. On the other hand, standard surgical procedures are very difficult and due to their high risks not practicable in early childhood. The distraction osteogenesis enables us to correct hypoplastic mandibles, so that secondary malformations of the midfacial complex can be avoided. During the operation the hypoplastic site of the mandible is osteotomized behind the last visible tooth bud and a bidirectional distractor is inserted. Following the principles of Ilizarov the new callus is lengthened gradually until the required length of the mandible has been achieved. Out of a total sample of 27 patients 3 case reports of young children are presented. The new surgical concept describes new treatment perspectives.

Adolescent↗
PubMed1996

Correction of mandibular hypoplasia by means of bidirectional callus distraction.

The method of gradual callus distraction proved to be very useful in augmenting hypoplastic mandibles. When performing our first series using a unidirectional distractor, we faced some problems in determining the direction of lengthening. Moreover, postoperative adjustments were not possible. On the basis of this experience, we developed a bidirectional lengthening device consisting of two limbs and a variable angulation piece. This allows distinct control of the vertical and horizontal components of the distraction. The method proved effective and reliable in 18 patients with various degrees of mandibular hypoplasia. The median follow-up period was 10 months (range, 1-19 months).

Adolescent↗
PubMed1996

[Mandibular micrognathism as a sequela of early childhood capitulum fractures and their treatment using distraction osteogenesis].

We report about our experience in five patients who suffered from a mandibular micrognathia after ancylosis of the temporomandibular joint. At first the ancylosis was removed using a costochondral graft. About one year later, the mandible was cut by an osteotomy behind the last visible toothbud and a distractor was inserted. The mandible was to a slide overcorrection. This has to be taken into account to compensate a certain relapse. At first we used an unidirectional device, for one and a half years we have used a bidirectional device (Normed from Tuttlingen/Germany) which enables us to correct mandibular hypoplasias more adequately. Up to now our experience shows, that gradual callus-distraction leads to stable normalization of mandibular hypoplasias. Functional problems concerning chewing and speech are solved, the dramatical improvement of the profile of the face may avoid psycho-social problems for these patients.

Adolescent↗
PubMed1995

[Standardized documentation of patho-anatomic findings using ADT (Association of German Tumor Centers) tumor forms for malignancies of the mouth, jaw and face (version III)].

The documentation form for pathohistologic findings (version III) for tumors of the maxillofacial region is presented. It is part of the site-specific documentation of the German Association of Tumor Centers (ADT). Its handling is explained by instructions which are based on the ICD-O classification and the TNM system. The prognostic relevance of the standardized documentation has already been proven by various histomorphologic investigations concerning oral and oropharyngeal cancer. By means of a multicentric observational study the German Austrian Swiss co-operative group DOSAK will develop a new prognostic model for oral and oropharyngeal cancer.

Documentation↗
PubMed1995

Lengthening of the hypoplastic mandible by gradual distraction in childhood--a preliminary report.

Uni- or bilateral mandibular hypoplasia can be associated with various syndromes or is acquired after early traumatic or inflammatory disease in the temporomandibular joint (TMJ). Early treatment is necessary to avoid consequent impairment of midfacial growth. The standard treatment of these malformations consists of the application of bone grafts which can lead to unpredictable growth. Furthermore, these procedures often require intermaxillary fixation and sometimes blood transfusions. Lengthening of the mandible by gradual distraction, according to the method of Ilizarov, opens new perspectives for interceptive therapy. This paper reports on this method applied in 9 cases of mandibular hypoplasia. Out of 3 bilateral and 6 unilateral mandibular distractions the average amount of bone lengthening was 21 mm, ranging from 15 to 25 mm. In order to facilitate ossification, the mandibles were maintained in external fixation for an average of 9 weeks subsequent to the period of active lengthening. Thereafter, immediate postoperative orthodontic treatment is necessary to avoid a relapse. No complications were noted during the follow-up period (max 17 months).

Adolescent↗