Wal, K.G.H. van der

Osteoradionecrosis of the external auditory canal: Three cases involving reconstruction with transposition of a split temporalis muscle flap (Article)

2012-10-01T00:00:00Z

Objective: Osteoradionecrosis of the temporal bone is an uncommon but well documented finding after radiotherapy in the head and neck region, and results in exposed, necrotic bone with a soft tissue defect in the external auditory canal. The defect can be treated either conservatively or surgically. This paper aims to describe the results of reconstruction of the external auditory canal by transpositioning of the superficial layer of either the anterior or posterior part of the temporalis muscle to cover the defect. Patients and methods: Three patients with large, symptomatic defects in the external auditory canal were treated with transposition of the superficial layer of the temporalis muscle. Results: The duration of follow up was 4 to 16 months. No complications occurred. In all patients, re-epithelialisation was complete within 3 months. Conclusion: During reconstruction of the external auditory canal, transposition of the superficial layer of the temporalis muscle provides a reliable flap with a satisfactory outcome.

De kunst van het loslaten (Farewell Lecture)

2012-05-25T00:00:00Z

Afscheidsrede prof.dr. K.G.H. van der Wal, Hoogleraar Kaakchirurgie Erasmus MC, uitgesproken op 25 mei 2012

Introduction of the "Rotterdam mandibular distractor" and a biomechanical skull analysis of mandibular midline distraction (Article)

2011-09-15T00:00:00Z

The Rotterdam mandibular distractor (RMD) is a slim, rigid, boneborne distractor for use in midline distraction of the mandible. We did a biomechanical study to compare the RMD with the Trans Mandibular Distractor-flex (TMD-flex). This included an anatomical biomechanical study that was conducted on 9 dentate human cadaveric heads using both the RMD and the TMD-flex. In the vertical plane less tipping was measured in the RMD group than in the TMD-flex group. Significantly less skeletal tipping was found in the horizontal plane in the RMD group (P = 0.021). There was minimal difference in the intercondylar distance between the groups. As the amount of lateral displacement of the condyle was similar in both groups and there was less rotational movement in the RMD group, the TMD-flex would be expected to increase stress on the temporomandibular joint. As a result of the increased parallel widening in the vertical plane, more basal bone is being created and less relapse is expected using the RMD. The study design involves an in vitro anatomical model and conclusions must be drawn with care. At present clinical studies are under way and results will follow.

Gingival overgrowth in pompe disease: A case report (Article)

2011-08-01T00:00:00Z

Pompe disease, or glycogen storage disease type 2, is a rare inheritable metabolic disease caused by a deficiency of the lysosomal enzyme acid α-glucosidase. Patients with the classic infantile form of Pompe disease present with symptoms during the first 3 months after birth, and most will die within their first year. Recently, enzyme replacement therapy (ERT) with recombinant human α-glucosidase became commercially available for Pompe disease. This is a case report of an 8-year-old girl with the infantile form of Pompe disease who is one of the longest survivors through ERT. The patient was tetraplegic when she started ERT. At age 3 years, she developed massive gingival overgrowth and could not close her mouth, prompting a reduction of the gingival overgrowth surgically. We expected that massive accumulation of glycogen would explain the gingival overgrowth. However, histopathology of the gingiva tissue showed marked glycogen accumulation in smooth muscle cells of the arteries, but the glycogen content in fibroblasts did not exceed that of control individuals. Further, there was an increase of immature collagen in the connective tissue, and signs of a mild chronic inflammation. We concluded that glycogen storage is not a direct causative factor of gingival overgrowth in our patient. Chronic inflammation, dryness of the gingiva, or even the minimal glycogen accumulation in the fibroblasts may have played a role.

Additional orthognathic surgery following le Fort III and monobloc advancement (Article)

2011-07-01T00:00:00Z

Severe midface hypoplasia in patients with various craniofacial anomalies can be corrected with Le Fort III or monobloc advancement. Often additional corrective orthognathic surgery is indicated to achieve Class I occlusion and a normal inter-jaw relationship. This study evaluated the incidence of, and the surgical indications for, secondary orthognathic surgery following Le Fort III/monobloc advancement. The total study group consisted of 41 patients: 36 patients with Le Fort III advancement and 5 patients with monobloc advancement. Seven patients underwent additional orthognathic surgery. Of the resulting 18 non-operated patients older than 18 years at the end of follow-up, Class I occlusion was observed in 11 patients. In the remaining patients malocclusions were dentally compensated with orthodontic treatment. None of the patients was scheduled for additional orthognathic surgery due to the absence of functional complaints and/or resistance to additional surgery. Le Fort III and monobloc advancement aim to correct skeletal deformities on the level of zygoma, orbits, nasal area and forehead, but Class I occlusion is frequently not achieved. Additional orthognathic surgery is often indicated in patients undergoing Le Fort III or monobloc advancement. Naso-endoscopic analysis of the upper airway and the outcomes of sleep studies may influence the orthognathic treatment plan.

Mandibular midline distraction: A systematic review (Article)

2011-06-29T00:00:00Z

Introduction: A systematic review of mandibular midline distraction (MMD) was carried out to assess effectiveness, treatment related difficulties, complications and biomechanical effects of this treatment modality objectively. Material & methods: Randomized controlled trials (RCT), controlled clinical trials (CCT) and case series concerning MMD with a sample size of >5 were searched electronically in Pubmed/Medline, Embase, Cochrane and CENTRAL up to September 6th 2010. Results: 85 unique articles were found of which 22 met our inclusion criteria. The study designs of the articles found were prospective (9), retrospective (9) or uncertain (2). One clinical trial and no randomized clinical trials were found. The methodological quality was considered low in most articles. Conclusion: Generally MMD is a safe and effective treatment modality to treat transverse mandibular discrepancies, however controversies still exist: choice of distractor, surgical setting, distraction rate, start of orthodontic treatment and relapse. In addition, little is known about patient experience and quality of life after treatment. Further prospective trials are necessary to address these controversies and questions.

Hyperbaric oxygen therapy in the management of radiation-induced injury in the head and neck region: A review of the literature (Article)

2010-08-01T00:00:00Z

Purpose: Radiotherapy is generally used in the treatment of malignant tumors in the head and neck region. It causes a hypoxic, hypocellular, and hypovascular environment that leads to injury to surrounding normal tissue, both acute and chronic, ranging from xerostomia to osteoradionecrosis. These side effects are debilitating and greatly influence quality of life in these patients. Hyperbaric oxygen (HBO) therapy is clinically used to prevent or treat these side effects by enhancing oxygen pressure and thereby regeneration. Although this therapy is widely applied, its mechanism of action is still poorly understood, and controversy exists in the literature about its clinical use. This review therefore aims to analyze the existing experimental and clinical research on this topic. Materials and Methods: A systematic search was performed in PubMed for experimental and clinical studies conducted regarding the use of HBO therapy in previously irradiated tissue, in the period from January 1990 to June 2009. Results: Experimental research is scarce, and clinical studies are especially lacking in terms of randomized controlled studies. Although discussions on the subject are ongoing, most studies suggest a beneficial role for HBO in previously irradiated tissue. Conclusion: Further research, both experimental and clinical, is necessary to unravel the working mechanism of HBO therapy and validate its clinical use.

Three-dimensional airway changes after le fort III advancement in syndromic craniosynostosis patients (Article)

2010-08-01T00:00:00Z

Background: To investigate the changes of upper airway volume in syndromic craniosynostosis patients following Le Fort III advancement, computed tomographic scans were analyzed and related to the amount of advancement. Methods: In this retrospective study, the preoperative and postoperative computed tomographic scans of 19 patients with syndromic craniosynostosis who underwent Le Fort III advancement were analyzed. In four cases, preoperative polysomnography demonstrated obstructive sleep apnea. The airway was segmented using a semiautomatic region growing method with a fixed Hounsfield threshold value. Airway volumes of hypopharynx and oropharynx (compartment A) and nasopharynx and nasal cavity (compartment B) were analyzed separately, as was the total airway volume. Advancement of the midface was recorded using lateral skull radiographs. Data were analyzed for all patients together and for patients with Crouzon/Pfeiffer and Apert syndromes separately. Results: Airway volume increased significantly in compartment A (20 percent; p = 0.044) and compartment B (48 percent; p < 0.001), as did total airway volume in (37 percent; p < 0.001) in the total study group. No significant differences in volume changes were found comparing Apert with Crouzon/Pfeiffer patients. No distinct relation could be found between advancement of the midface and volume gain either in the total study group or in Apert and Crouzon/Pfeiffer patient groups separately. Postoperative polysomnography showed significant improvement of obstructive sleep apnea in all four patients. Conclusions: A significant improvement of the upper airway after Le Fort III advancement in syndromic craniosynostosis patients is demonstrated. No distinct relation could be observed between advancement and airway volume changes. Copyright

Histomorphometric comparison between continuous and discontinuous distraction osteogenesis (Article)

2009-10-01T00:00:00Z

Introduction: Experimental research on optimising the distraction protocol has been performed extensively in the past. However, relatively little research has been done on the rhythm of distraction. Findings in the orthopaedic literature showed that the outcome of distraction osteogenesis (DO) is positively influenced by increasing the rhythm of distraction. The aim of this study is to quantitatively compare continuous with discontinuous rhythms of distraction in rabbits. Materials and methods: Tissue blocks of regenerated bone were harvested from thirty-eight young adult female New-Zealand White rabbits. After a latency period of three days, rabbits were subjected for eleven days to either single daily activation of the distractor at a rate of 0.9 mm/d, or triple daily activation at a rate of 0.9 mm/d, or continuous activation at a rate of 0.9 mm/d. After three weeks of consolidation, bone regenerates were analysed using histomorphometry. Results: The continuous DO group showed significantly (p < .01) more regenerate bone volume in the central part of the regenerate than the discontinuous DO groups. Higher osteoblastic activity was seen, as well as more blood vessels (p < .05). Bone volume and the number of blood vessels correlated significantly in the central part of the regenerate (p < .05). Also, the early mineral apposition rate (MAR) was higher than the late MAR (p < .05). Conclusions: Continuous DO significantly accelerates bone formation when compared with discontinuous DO.

Stability, tipping and relapse of bone-borne versus tooth-borne surgically assisted rapid maxillary expansion; a prospective randomized patient trial (Article)

2009-04-01T00:00:00Z

This study evaluated stability, tipping and relapse after surgically assisted rapid maxillary expansion (SARME), comparing bone-borne and tooth-borne devices, in skeletally matured non-syndromal patients with transverse maxillary hypoplasia. The study is a randomized, open-label, clinical trial. Patients were randomized to bone-borne (n = 25) and tooth-borne (n = 21) groups. The surgical technique for corticotomy was the same in both groups. Expansion was performed using a bone-borne or tooth-borne device. Dental study casts, lateral and postero-anterior cephalograms were taken before treatment, after the distraction phase and at 12-month follow up. Stability, segmental maxillary tipping and relapse were studied. 23 bone-borne and 19 tooth-borne patients were analyzed. There were no significant differences between the two groups. Widening was comparable at canine, premolar and molar level. Relapse was not significant and at follow up the significant increase in distance was sustained. A significant increase in palatal width, at premolar and molar level, occurred in both groups. The maxilla moves slightly downward in SARME. Segmental maxillary tipping occurred in both groups and did not affect relapse. There is no significant difference between the two groups. In SARME, the widening achieved at dental level is stable after 12 months. Over-correction is not necessary. Tipping of the maxillary segments and increases in the retention period are equal in both groups.

Continuous Versus Discontinuous Distraction: Evaluation of Bone Regenerate Following Various Rhythms of Distraction (Article)

2009-04-01T00:00:00Z

Purpose: To investigate continuous distraction osteogenesis (DO) of the nasal bones in a rabbit model, and to compare data from this continuous DO study with data from a previously conducted discontinuous DO study. In addition, radiographic and ultrasonographic bone-fill scores were determined to investigate whether these scores provided reliable predictive value for the amount of new bone formation in the distraction area. Materials and Methods: Skeletally mature female New Zealand White rabbits were subjected to distraction of the nasal bones. A custom-made continuous distractor was used to perform automatic non-stop distraction. Bone data were obtained from radiography, ultrasonography, and microcomputed tomography. Data from this experiment were compared with data from a previous study on discontinuous distraction rhythms. Results: Ultrasonographic bone-fill scores correlated significantly to actual bone volume in contrast to radiographic bone-fill scores. Bone volume was significantly higher in the continuous DO group compared with the discontinuous DO groups. Conclusion: Continuous distraction resulted in accelerated osteogenesis compared with discontinuous distraction. Furthermore, bone-fill scores based on ultrasonography showed a significant correlation with actual bone volumes.

Sensory Testing of Inferior Alveolar Nerve Injuries: A Review of Methods Used in Prospective Studies (Article)

2009-02-01T00:00:00Z

Purpose: The inferior alveolar nerve (IAN) can be injured during trauma or surgery. So far there is no consensus for evaluating IAN injury. This study aimed to identify a testing method suitable for daily clinical practice which allows us to identify nerve injury, grade its severity, and monitor its recovery. Materials and Methods: Covering a 20-year period, prospective studies on sensory changes after mandibular procedures were reviewed regarding sensory testing methods; 75 studies on third molar removal, osteotomy, fracture, and implants were included. Results: These studies reported varying incidences. In third molar removal and implant studies, a limited number of sensory tests were used, whereas in osteotomy and fracture studies more detailed testing was performed, using reproducible tests like light touch test with Semmes-Weinstein monofilaments and 2-point discrimination. Conclusions: Sensory function was not uniformly tested and presented, making a comparison of data impossible and highlighting the need for uniform testing methodology. Based on the results of this review, the light touch test with Semmes-Weinstein monofilaments for grading is recommended, using a grid and control site describing unilateral or bilateral nerve injury. Additionally, a visual analog scale-based questionnaire should be used to evaluate subjective sensibility. Using this method to test IAN injuries will allow comparison of future studies and provide valuable insight in the severity and prognosis of IAN injuries.

Relapse and Stability of Surgically Assisted Rapid Maxillary Expansion: An Anatomic Biomechanical Study (Article)

2009-01-01T00:00:00Z

Purpose: This anatomic biomechanical study was undertaken to gain insight into the underlining mechanism of tipping of the maxillary segments during transverse expansion using tooth-borne and bone-borne distraction devices. Materials and Methods: An anatomic biomechanical study was performed on 10 dentate human cadaver heads using tooth-borne and bone-borne distraction devices. Results: The amount of tipping of the maxillary halves was greater in the tooth-borne group, but the difference was not significant. Four of the specimens demonstrated an asymmetrical widening of the maxilla. Conclusions: Segmental tipping was seen in both study groups. In this anatomic model, tooth-borne distraction led to greater segmental tipping compared with bone-borne distraction. Keep in mind, however, that this anatomic model by no means depicts a patient situation, and any extrapolation from it must be done with great care. The fact that the tooth-borne group demonstrated greater tipping might reflect the general opinion that bone-borne distraction causes less segmental angulation than tooth-borne distraction. Some tipping was seen in the bone-borne group, suggesting that overcorrection to counteract relapse will be necessary with this treatment modality.

Rabbits as a model for research into craniofacial distraction osteogenesis (Article)

2008-12-01T00:00:00Z

Various factors affect the choice of the appropriate animal for craniofacial research. We have evaluated the rabbit as a suitable animal for research on craniofacial distraction osteogenesis. We describe our experience with housing and handling them, surgical and experimental protocols, and compare them with other animals. We introduce, and describe the use of, a continuous hydraulic distractor on the nasal bones of the rabbit. Fifty-two skeletally mature New Zealand White rabbits were used. Forty-two of the 52 operations were uneventful. Ten of the fifty-two developed complications, of which two were animal-related, and the other eight distractor-related. During the experiments the animals stayed healthy, and the distraction procedures were well tolerated. Rabbits are excellent for use in biological research on craniofacial distraction osteogenesis. Specifically, their nasal bones are easily accessible, the size and shape of the nasal bones allow various commercially available as well as custom-made distractors to be attached to the bones easily, their care and housing are relatively simple and inexpensive, and harvesting of tissue for further analyses is no problem because their skulls are of a manageable size and shape compared with other laboratory animals.

Advancement of the midface, from conventional Le Fort III osteotomy to Le Fort III distraction: review of the literature (Article)

2008-09-01T00:00:00Z

Since its introduction in about 1950, the Le Fort III (LF III) procedure has become a widely accepted treatment for correction of midface hypoplasia and related functional and esthetic problems. As long-term surgical experience grows and improvements are made in technique, equipment and peri-operative care, the number of LF III procedures performed worldwide is increasing. A number of fundamental questions concerning the technique remain unclear, and large, conclusive studies are lacking owing to the relative rarity of severe midface hypoplasia. This literature review aims to address problems, such as the indication field, timing of surgery, rate of relapse and the use of distraction osteogenesis. An overview of the history and technique of LF III osteotomy and distraction is provided, together with a comprehensive review of the available clinical data.

Oral Manifestations of Oxalosis: A Case Report and Review of the Literature (Article)

2008-09-01T00:00:00Z

Surgically assisted rapid maxillary expansion in two cases of osteopathia striata with cranial sclerosis (Article)

2008-05-01T00:00:00Z

Osteopathia striata with cranial sclerosis (OS-CS) is a rare skeletal dysplasia characterized by linear striations of the long bones, osteosclerosis of the cranium, and extraskeletal anomalies. Osteosclerosis of the cranial and facial bones can lead to disfigurement and to disability due to the pressure on the cranial nerves. We report two cases of OS-CS where surgically assisted rapid maxillary expansion was performed for widening the extremely narrow maxilla. One should be aware of the disease-related problems and the possible complications that might occur with this type of patient.

Single versus triple daily activation of the distractor: no significant effects of frequency of distraction on bone regenerate quantity and architecture (Article)

2008-04-01T00:00:00Z

OBJECTIVES: To study the effect of two different frequencies of distraction on the quantity and architecture of bone regenerate using micro-computed tomography, and to determine whether radiographic and ultrasonographic bone-fill scores provide reliable predictive value for the amount of new bone in the distraction area. MATERIAL AND METHODS: Twenty-six skeletally mature rabbits underwent three full days of latency, after which midface distraction was started. Low-frequency group (n=12): a distraction rate of 0.9 mm/d achieved by one daily activation for 11 days to create a 10mm distraction gap. High-frequency group (n=12): idem, but three daily activations were used instead of one. Control group (n=2) underwent no distraction. After 21 days of consolidation, bone-fill in the distraction area was assessed by means of ultrasonography and radiography. Micro-computed tomography was used to quantify new bone formation and bone architecture. RESULTS: Relative bone volume (BV/TV) showed a tendency towards a difference (P=0.09) between the low and high-frequency groups. No significant differences were found for bone architecture. No significant correlation between BV/TV values and bone-fill scores was found. CONCLUSIONS: An increase in rhythm from one to three activations daily does not create significantly more bone. Bone-fill score values provided no reliable predictive value for the amount of new bone formation.

Oral squamous cell carcinoma in children; review of an unusual entity (Article)

2008-01-01T00:00:00Z

Most commonly, squamous cell carcinoma (SCC) of the oral cavity presents during the fifth and sixth decades of life. Less than 4% of these cancers occur in patients younger than 40 years of age. Only a small sample of this subgroup exists of pediatric patients (≤20 years), making oral SCC in children an extremely rare entity. An 11-year-old boy is presented who developed a SCC of the gingiva. The relevant literature of oral SCC in pediatric patients will be reviewed as well.

Recommendations for optimal distraction protocols for various animal models on the basis of a systematic review of the literature (Article)

2007-10-01T00:00:00Z

The principles of orthopaedic distraction osteogenesis (DO) have been successfully applied to the craniofacial skeleton, but the latency time, rate and rhythm of distraction, and length of the consolidation period that are optimal for long-bone distraction may be suboptimal for craniofacial DO. The aim of this study was to provide recommendations for optimal distraction parameters in animal experimental research on craniofacial DO. The data used were from studies, added to the PubMed database between 1 January 1973 and 1 January 2007, on the outcome of DO resulting from variations in a single distraction parameter while standardizing the other distraction parameters. Although experimental animal group sizes were rather small, especially in those studies that used large animals, and both skeletally mature and immature animals were used, the (in most cases quantitative) data provided useful information on the optimal parameters in craniofacial DO. A latency period may not be necessary at all. Distraction should be performed at a rate of 1mm/day (this may be halved when small animals such as rats are used) preferably with a continuous rhythm, followed by a consolidation period of 6-8 weeks. These recommendations can be used as basic guidelines for further animal experimental studies on craniofacial DO.

Complications and relapse in alveolar distraction osteogenesis in partially dentulous patients (Article)

2007-08-01T00:00:00Z

Vertical distraction of the alveolar process is an efficient method for augmentation prior to inserting dental implants. In this study, complications of this procedure and relapse of the transport segment were evaluated in partially dentulous patients. Twenty patients underwent distraction by means of extraosseous distractors. The location of the defects was the anterior mandible (4), posterior mandible (4), anterior maxilla (10) and posterior maxilla (2). Bone height was measured on panoramic radiographs preoperatively, after distraction and after implant placement at the mesial and distal point of the implant(s). Mean alveolar distraction was 6.5 mm at the mesial point (P < 0.001) and 6.1 mm at the distal point (P < 0.001). The mean relapse at the mesial point was 20% and at the distal point 17% (P < 0.05). The intraoperative and postoperative problems encountered were fracture (1) and lingual (4) and palatal (6) displacement of the transport segment. Overall complication rate was 55%. Of all implants placed (n = 63) one was lost. Implant success rate was 98%. Distraction seems to be a suitable treatment for vertically deficient alveolar bone, but a relatively high although manageable complication rate must be confronted, including considerable relapse.

FUNCTIE = VOЯM (Inaugural Lecture)

2006-06-20T00:00:00Z

Aan de vooravond van het 50-jarig bestaan van het specialisme Mondziekten en Kaakchirurgie mag ik, als eerste, invulling geven aan de gewone leerstoel Kaakchirurgie Erasmus Universiteit Rotterdam. U kunt niet meer om het orgaanspecialisme Mondziekten en Kaakchirurgie heen. Voor u staat een hoogleraar die 22 jaar gepokt en gemazeld is in de periferie. Het werken in een groot algemeen ziekenhuis als het Medisch Centrum Leeuwarden heeft, hoe kan het ook anders, een stempel gedrukt op mijn denken en handelen. 'Schrijven is een eenzaam avontuur' waren de woorden van Anna Blaman bij het verschijnen van haar roman 'Eenzaam avontuur'. Het schrijven van deze rede is niet anders en geeft mij de ruimte u deelgenoot te maken van mijn avontuur. In gedrukt Nederlands komt het woord 'mond' één keer voor op 6600 woorden. In romans komt het woord mond één keer voor op 2400 woorden. In deze rede slechts zeven keer. Merkwaardig zo realiseerde ik mij, terwijl het gelaat en de mond mijn werkterrein zijn. In de komende 45 minuten zal ik ingaan op mijn leeropdracht, het vakgebied van de kaakchirurgie, ook wel aangeduid als orale en maxillofaciale chirurgie, de opleiding, het onderwijs en het onderzoek. De titel van mijn rede 'Functie=Vo_m' vraagt om uitleg. De functie bepaalt de vorm en vice versa, de vorm bepaalt de functie. In de maxillofaciale chirurgie worden de mogelijkheden en beperkingen veelal bepaald door de Functie van het orofaciale systeem, die op zijn beurt weer Vorm-bepalend is voor het aangezicht. Afwijkingen van het gebit kunnen resulteren in een slechte kauwfunctie en in logopedische en skeletale afwijkingen. Waarschijnlijk heeft u zich afgevraagd waarom ik de R in spiegelbeeld heb laten drukken. De achterliggende gedachte hiervan is de beperkingen, die functieverbeterende ingrepen hebben op de uiteindelijke vorm te accentueren en te relativeren. We moeten helaas genoegen nemen met de beperkingen van het technisch haalbare. Door het hybride karakter van mijn specialisme, de tandheelkunde en de geneeskunde, leent de maxillofaciale chirurgie zich bij uitstek voor de diagnostiek en de chirurgische behandeling van functie- en vormveranderingen van het aangezichtsskelet.