Case report: fusion of positron emission tomography (PET) and computed tomography (CT) images for image-guided endoscopic navigation in maxillofacial surgery: clinical application of a new technique.

INTRODUCTION: Surgery based on computed tomography (CT) data is becoming increasingly important in the head and neck region. The technique for hardware fusion between positron emission tomography (PET) and computed tomography (CT) has only been established commercially in the last 4 years. The advantages over CT alone are obvious. The surgeon is simultaneously provided with a map of anatomical as well as of functional (metabolic) details. The fused images offer improved localization of malignant lesions and improved targeting of biopsy, especially for small lesions. PURPOSE: A new technique for image-guided tumour localization for maxillofacial surgery based on PET/CT-image fusion is described. PATIENT AND METHOD: A 78-year-old woman was admitted to this department with a tumour of the skull base. Three dimensional fusion of computed CT with positron PET images on a commercially available navigation system is described. After patient-to-image registration, a high-resolution endoscope was calibrated intraoperatively. Image-guided biopsy specimens were taken under direct visual control. CONCLUSION: PET/CT-image fusion proved extremely helpful to navigate the endoscope to the target lesion and to identify the tumour.

[Effects of Le-Fort-I-Osteotomy on nasalance scores]. / Veränderung der Nasalanz nach Le Fort-I Osteotomie.

BACKGROUND: Nasalance represents a measure of the relative amount of oral and nasal acoustic energy produced by a speaker. Literature shows changes in nasalance after surgery of the oropharynx. The aim of this prospective study was to evaluate the outcome of speech and nasalance scores after Le-Fort-I-Osteotomy. PATIENTS AND METHODS: A total of 20 individuals with normal speech development were examined preoperatively and 6 weeks postoperatively with the Nasometer 6200 (Kay-Elemetrics, USA) after bimaxillary surgery. The tone materials used comprised the standardized text passage: "Ein Kindergeburtstag", the vowels: /a/, /e/, /i/, /o/, /u/ and a syllable repetition subtest. RESULTS: All patients showed changes in nasalance scores 6 weeks postoperatively. There were no significant changes reading the standard text. The syllable repetition test showed significant changes for repetition of "ma ma ma" and "na na na" (p=0,003, respectively p=0,033). Intonation of the vowel /a/1 also revealed significant changes regarding the pre- and postoperative values (p=0,006). However, the obtained values had no significant impact on the nasality characteristics of speech. CONCLUSION: This study confirms that maxillary osteotomies can result in significant changes of nasalance scores. However these changes do not have any impact on normal speech and voice.

Anterior transmandibular osteodistraction: clinical and model observations.

INTRODUCTION: The aim of this paper was to study the effect of transmandibular distraction on the periodontal and dental structures, and the initial movements of the mandibular halves, when using an axial plane non-rigid bone-borne distractor (TMD). MATERIAL AND METHODS: Fourteen patients undergoing bimaxillary transverse osteodistraction had their six lower anterior teeth assessed for mobility, sensitivity, and pocket depth. Recordings were made pre-operatively, post-distraction, post-consolidation and at 1-year follow-up. Selected landmarks on pre-operative and post-consolidation models were also digitised in three dimensions to study individual tooth movements, and positional changes of the mandibular halves. RESULTS: Pockets depths around the incisor teeth increased during the consolidation period (probably due to reduced oral hygiene), but returned to normal by the 1-year post-operative consultation. Tooth mobility increased temporarily in the active phase (central incisors, lateral incisors) and in the consolidation phase (lateral incisors, canine teeth). Sensitivity to cold was temporarily lost in the incisor teeth, probably as a result of 'apical contusion'. One central incisor was inadvertently apically osteotomized and needed root canal treatment. The angle between the mandibular halves closed by 9.4 degrees. CONCLUSION: Periodontal and dental morbidity is transient and limited to the distraction and consolidation period, as long as the tooth apices are avoided when the osteotomy is performed. A step-design osteotomy may be preferable when the central incisor apices are close to each other. The transmandibular distractor (TMD) allows for rotation at the temporomandibular joints.

Simultaneous orbital expansion and intraoral distraction osteogenesis of upper and lower jaws in a patient with hemifacial microsomia.

BACKGROUND: Correction of a micro-orbit, caused by clinical anophthalmia is a very challenging task. In hemifacial microsomia a micro-orbit may be combined with hypoplasia of the malar and the ascending mandibular ramus. MATERIAL: A 5-year-old patient with hemifacial microsomia is described. Hypoplasia of the malar bone and the tilted occlusal plane were corrected by means of intraoral distraction osteogenesis in the upper jaw following precise simulation surgery on a 3D-model. At the same time, the ascending mandibular ramus was lengthened with a second distraction device and a spherical tissue expander was inserted into the hypoplastic orbit. RESULTS: The malar as well as upper and lower jaws were lengthened and positioned symmetrically. The orbital cavity was expanded to 79% of that of the healthy side. Following removal of the distraction devices, the expander was exchanged for a larger one and orbital expansion was continued until overcorrection of the orbit up to 118 percent was achieved. CONCLUSION: Orbital expansion is a minimally invasive method of enlarging the volume of the eye socket three-dimensionally. Intraorally activated buried distraction devices enable "growth" of the jaws making bone transplants avoidable in many cases. By combining both methods, complex malformations can be corrected simultaneously in children.

Cephalometric and occlusal outcome in adults with unilateral cleft lip, palate, and alveolus after two different surgical techniques.

OBJECTIVE: To assess differences in the aesthetic and functional long-term results of one-stage and two-stage surgical and orthodontic treatment in patients with cleft lip, palate, and alveolus. DESIGN: Sixty adult patients who were operated on as children for unilateral cleft lip, palate, and alveolus were examined. In every patient the lip was closed using Tennison's technique. Thirty patients had soft and hard palate closure in two stages and 30 patients in a single stage. Lateral cephalometric and model analyses were conducted at a mean age of 18.4 years. RESULTS: In the model analysis, transverse narrowing was seen in all patients after two-stage operations and in three patients after one-stage operations. The deficit was more severe in the molar region in the two-stage group and nearly similar in the premolar and molar region in the one-stage group. A sagittal deficiency in the anterior maxilla was found in 26 patients after two-stage operations and in 16 patients after one-stage operations. In the lateral cephalometric analysis, the mean sella-nasion-point A angle in the one- and two-stage group was 78.2 degrees and 76.8 degrees, respectively. The ANB angle was normal in both groups. In both groups the inclination of the midface was low. There was a low posterior facial height. Minor scarring was seen in the single-stage group. CONCLUSION: A more severe impairment of growth of the maxilla in the sagittal and frontal plane was observed after two-stage operations on the cleft palate.

Differences in cephalometric and occlusal outcome of cleft palate patients regarding different surgical techniques.

INTRODUCTION: The purpose of this study was to assess differences of the long-term results following surgical treatment in patients with cleft palate treated by two different surgical concepts. PATIENTS: Fifty-nine adult patients operated on for cleft palate were examined. Thirty palates were closed by a two stage (Widmaier and Veau) and 29 by a single-stage procedure (Veau's pedicled flap). METHODS: Lateral cephalometric and model analysis was performed. In the cephalometric analysis, the vertical and horizontal parameters of the position of maxilla and midface and transverse and sagittal dimensions of the models were compared between the two groups. RESULTS: Model analysis: According to the Bolton analysis the maxillary dental arch was too large in 22 patients in each group. The other patients had mandibular arches that were too large. In 18 patients with two-stage closure and in 9 patients with one-stage closure, a space deficit in the lateral part of the maxilla was observed. Persisting transverse deficits were seen in all patients with two-stage repairs and in 11 patients with one-stage repairs. The deficit was more severe in the molar area in the first group and almost equally severe in the premolar and the molar regions of the second group. A sagittal deficiency was found more often in patients with two-stage repairs while Angle's class I occlusion was seen more often in patients with one-stage surgery. Lateral cephalometry: Similar SNA-angles were seen in both groups whereas the ANB-angle was greater following two-stage repair. In both patient groups a low inclination of the midface was seen. The vertical dimension of the midface in comparison with the lower face was normal in the one-stage group; in the other group a deficiency of the anterior midface height was registered. CONCLUSION: There was a more severe growth impairment of the midface in patients with this type of two-stage palatal repair. The horizontal deficiency was similar in both groups. The long-term occlusal result revealed smaller sagittal and transverse deficiencies in patients with this type of single-stage closure.