Evaluation of airflow characteristics before and after septoplasty in unilateral cleft patients with a deviated nasal septum: a computational fluid dynamics study.

The aim of this study was to evaluate changes in airflow characteristics before and after septoplasty in unilateral cleft lip and palate (UCLP) patients using computational fluid dynamics (CFD) models. The study was designed as a prospective cohort study involving pre- and postoperative computed tomography data from 12 UCLP patients with a deviated nasal septum who underwent septoplasty. CFD analysis of nasal airflow was conducted to study changes in velocity, pressure, volume, nasal resistance, and wall shear stress of the nasal domain before and after surgery. The study results demonstrated a statistically significant difference in pressure drop after septoplasty: median 116.10Pa (interquartile range (IQR) 749.02Pa) preoperative compared with 43.39Pa (IQR 349.01Pa) postoperative (P= 0.004). Maximum wall shear stress was found to be approximately three times lower after septoplasty: median 6.15 Pa (IQR 1908.62 Pa) preoperative versus median 2.51 Pa (IQR 540.06 Pa) postoperative (P=0.002). Changes in nasal resistance were also found to be statistically significant: median 460.59 Pa·s/l (IQR 1946.99 Pa·s/l) preoperative versus median 166.61 Pa·s/l (IQR 694.08 Pa·s/l) postoperative (P=0.04). These values demonstrate significant changes in flow dynamics after surgery indicative of a more uniform airflow pattern and stabilization of the nasal mucosa.

Minimally-invasive anterior maxillary distraction technique in patients with cleft lip and palate and maxillary deficiency: an evaluation of 106 patients.

Our aim was to evaluate the feasibility of a minimally-invasive surgical technique for anterior maxillary distraction osteogenesis to correct maxillary hypoplasia in patients with clefts. A modified Y distractor was placed intraorally in 106 patients with cleft- associated maxillary deficiency to facilitate protraction of the maxilla. Subsequently the patients had an anterior maxillary osteotomy through a minimally invasive incision, followed by activation of the appliance at the rate of 0.8mm/day until positive overjet was achieved. The patient's lateral cephalograms were evaluated preoperatively (T1), after activation (T2), and one year postoperatively (T3). Collected data were assessed with the paired t test, and probabilities of < 0.001 were accepted as significant. A mean (SD) of 10.4 (2.58) mm anterior maxillary advancement was obtained in all patients after 10-13 days of distraction. The sella-nasion-point A (SNA) angle increased from 75.37° to 83.01°. When we compared the cephalometric variables at T1 and T2, the mean maxillary length and overjet at T2 were significantly higher (p<0.001). The comparison of mean values at T2 and T3 was not significant. Minimally invasive anterior maxillary distraction with the modified Y distractor resulted in changes after activation that were consistent one year postoperatively, making it a conservative, less traumatic, and effective treatment of cleft-related maxillary deficiency.

Long-term effect of presurgical nasoalveolar molding on growth of maxillary arch in unilateral cleft lip and palate: randomized controlled trial.

The objective of this study was to investigate the long-term effect of presurgical nasoalveolar molding (PNAM) on growth of the maxillary arch through early childhood until 6 years of age in complete unilateral cleft lip and palate (UCLP) patients presenting for PNAM at different ages. Complete UCLP patients who were treated at our centre were divided into two groups. The study group underwent PNAM and was further subdivided into three subgroups (PNAM initiated within 1 month, between 1 and 6 months, and between 6 and 12 months of age in subgroup I, II, and III, respectively). The control group did not undergo PNAM and was further subdivided into three subgroups. Patients were evaluated at T1 (first visit), T2 (before cheiloplasty), and T3 (at 6 years). Between T1and T2, the intersegment distance (ISD) reduced significantly in the study group but increased in the control group, whereas the intercanine width (ICW) in both the study and control groups did not show significant change. Between T2 and T3, ISD and ICW were reduced significantly in the control group due to arch collapse, whereas in the study group, ISD reduced slightly with ICW remaining almost similar to noncleft norms. We conclude that reduced ISD following PNAM improves arch symmetry and stability, and thus may prevent arch collapse in the long term.

Bimaxillary 'rotation advancement' procedures in patients with obstructive sleep apnea: a 3-dimensional airway analysis of morphological changes.

The aim of this retrospective three dimensional (3D) computed tomographic analysis was to investigate the morphological airway changes in 17 obstructive sleep apnea (OSA) patients following bimaxillary rotation advancement procedures. Morphological changes of the nasal cavity and naso-, oro- and hypopharynx were analysed separately, as were the total airway changes using nine parameters of airway size and four of shape. The Wilcoxon test was used to compare airway changes and the intraclass correlation coefficient to qualify inter-observer reliability. Following bimaxillary advancement and anti-clockwise maxillary rotation, the total airway volume and the lateral dimension of the cross-sectional airway increased significantly. The total length of the airway became shorter (p<0.05). Remarkable changes were seen in the oropharynx: the length, volume, cross-sectional area (CSA), antero-posterior and medio-lateral distance changed (p<0.05). This combined with a significant 3D change in the shape of the airway from round to elliptical. The average cross-sectional oropharyngeal area was nearly doubled, the minimal CSA increased 40%, and the hyoid bone was located more anterior and superior. Inter-examiner reliabilities were high (0.89). 3D airway analysis aids the understanding of postoperative pathophysiological changes in OSA patients. The airway became shorter, more voluminous, medio-laterally wider, and more compact and elliptical.

A comparison of results using nasoalveolar moulding in cleft infants treated within 1 month of life versus those treated after this period: development of a new protocol.

UNLABELLED: The objectives of this study were to: evaluate the effects of nasoalveolar moulding (NAM) in complete unilateral cleft lip and palate infants presenting for treatment at different ages; propose a new NAM protocol in these patients; improve the predictability of NAM. Study groups comprised: group I (n=15) treated with NAM within 1 month of age; group II (n=15) treated with NAM between 1 and 5 months of age. CONTROL: group III (n=15) comprised of non-cleft 18-month old children. A standard protocol was followed. Patients were evaluated before initiation of NAM, before cheiloplasty and at 18 months. 7 linear anthropometric measurements were compared using dento-facial models. Statistical analysis before and after NAM revealed that group I patients demonstrated 81%, 198%, 69% and 145% improvement in intersegment distance, nasal height, nasal dome height and columella height respectively; whilst group II patients demonstrated 51%, 33%, 21% and 38% improvement for the same. At 18 months, group I patients closely resembled group III patients. This study concluded that the effects of NAM were most significant in group I. Group II patients also benefited from NAM, although to a lesser extent. This study validates the use of NAM in infants presenting late for treatment.

A rare case of multiple oblique facial clefts with supernumerary teeth: case report.

Oblique facial clefts are rare congenital anomalies that can present alone or in association with other craniofacial anomalies. A high degree of clefting in the embryo may lead to hyperdontia secondary to dichotomy of the dental lamina. Multiple facial clefts with hyperdontia are clinically challenging and demand comprehensive rehabilitation. This article reports a case of multiple oblique facial clefts of variable severity with multiple supernumerary teeth in a 12-year-old boy. The varied clinical presentation along with the rarity of the occurrence mandate documentation.

Slow and continuous application of human recombinant bone morphogenetic protein via biodegradable poly(lactide-co-glycolide) foamspheres.

Bone morphogenetic proteins (BMPs) are multifunctional cytokines that were originally identified as molecules that induce bone and cartilage formation in vivo. In order to increase the efficacy of this potent protein for application in medicine, a carrier system is needed to retain the BMP at the preferred site. Here we present and characterize a slow-release carrier system for pure human recombinant (rh)BMP. The large porous microspheres, called 'foamspheres', are biodegradable, because they consist of poly(lactide-co-glycolide) acids and release loaded rhBMP slowly and continuously. In vivo studies in rodents revealed that rhBMP-loaded foamspheres increased the thickness of the calvarial bone of rats by 222%. When the same amount of rhBMP was applied via a gelatine-based hydrogel, the increase in bone height was only 66%. Thus, the carrier system for rhBMP is an important factor for the efficacy of BMPs.

Disulfide bridge conformers of mature BMP are inhibitors for heterotopic ossification.

Heterotopic ossification is a frequent complication in patients who have suffered head and neck traumas or undergone total hip replacement. Heterotopic ossification occurs when osteogenic precursor cells present at the ectopic site receive the necessary signal(s) to differentiate into osteoblasts. At the protein level, the key factors in differentiation of cells to the osteogenic lineage are BMPs. Stable BMP variants derived from the identical amino acid sequence but with different disulfide bridge configurations have been investigated and found to be capable of inhibiting ossification in vitro and in vivo in rodents. These findings provide a concept for the straightforward development of a novel class of BMP antagonists that could lead to new treatments for traumatically and genetically induced heterotopic ossification and also, possibly, for disorders in which other members of the TGF-beta superfamily are involved.

The role of a posteriorly inclined condylar neck in condylar resorption after orthognathic surgery.

Recently, it has been reported that a posteriorly inclined condylar neck is associated with condylar resorption following orthognathic surgery, although its role in resorption remains unknown. By cephalometric screening of 240 patients with Angle Class II occlusion 2 years after orthognathic surgery, 11 patients with postoperative condylar resorption were identified. The preoperative posterior inclination of the condylar neck and the surgical risk factors mentioned in the literature, particularly surgically induced counterclockwise rotation of the mandibular proximal segment were evaluated. In all 11 cases, the condylar neck was clearly inclined posteriorly. Counterclockwise rotation of the proximal segment was also observed in all cases, and it amounted to 6.7 degrees (2.5-12 degrees) on average. The contributing role of a posteriorly inclined condylar neck in connection with surgical mandibular movement in postoperative condylar resorption is discussed.

[Bone substitutes]. / Knochenersatzmaterialien.

The application of autogenous bone transplants is still the gold standard for all reconstructive surgery. The wish of surgeons for alternatives to autogenous bone grafts is reflected in the development of a variety of bone graft substitutes of synthetic or biological origin. The following review article is meant to provide the reader with a critical overview of all the alternative materials. In addition, we want to point to the tremendous progress made on this subject, made possible by the joint effort of surgeons and basic researchers. The results of this collaboration show that in the near future a new gold standard for successful reconstructive surgery will emerge and replace the use of autogenous bone transplants.

Temperature mapping of magnetic resonance-guided laser interstitial thermal therapy (LITT) in lymphangiomas of the head and neck.

BACKGROUND AND OBJECTIVE: Lymphangiomas of the tongue and neck are uncommon benign congenital lymphatic tumors. These vascular lesions are difficult to treat, frequently recur, and can cause patients significant morbidity. Treatment may also be complicated by adjacent vital anatomic structures. Magnetic resonance (MR)-controlled laser-induced interstitial thermotherapy (LITT) has been proven to be a noninvasive safe treatment. Real-time monitoring of tissue temperature with thermosensitive sequences allows controlled coagulation necrosis. STUDY DESIGN/MATERIALS AND METHODS: LITT was performed in a lymphangioma specimen ex vivo. In four patients (eight procedures) with lymphangiomas of the tongue and neck, MR-guided LITT was performed with a percutaneous approach in a multiapplicator technique. The laser system consisted of a titanium catheter and a protective catheter. The dome of the fiber end had a diameter of 1.4 mm with an active length of 20 mm. Temperature sensitive sequences were used in a 0.5 T open-configured MR scanner with the proton frequency shift technique to map the spatial and temporal distribution of Nd:YAG laser effects (7 Watts, 30 pulses per second, 10 minutes/location). Postoperative MR follow-up was performed at 1 week and at 3 months. In three patients, partial resection of the tumor was performed 6 months after LITT. RESULTS: In three patients, MR clearly showed a diminished tumor volume. All four patients reported subjective amelioration and in three patients former functional problems, such as speech and swallowing were improved. MR thermometry allowed accurate demarcation of changes by heat and distinction of affected tumor volume (3.0 cm +/- 0.3 cm). The histology of the patients 6 months after LITT showed laser-induced fibrosis of former lymphatic tissue. CONCLUSION: The results suggest that LITT can be performed safely with tissue preserving of vital structures and can be effective in the treatment of deep tumors, such as lymphangiomas. However, given the nature of the lesion, the potential for recurrence exists no matter what modality is chosen.

Surgical risk factors for condylar resorption after orthognathic surgery.

OBJECTIVE: The purpose of this study was to look for surgical risk factors for condylar resorption after orthognathic surgery. STUDY DESIGN: Seventeen patients of a group of 452 patients who had undergone orthognathic surgery consecutively and who were in accordance with the inclusion criteria of this study showed postoperative condylar resorption (group I). Preoperative cephalometric characteristics and surgically induced movements of this group were compared with a control group of 17 of 452 patients (group II) in whom postoperative condylar resorption and skeletal relapse did not develop, despite mandibular retrognathism (ANB angle >4 degrees) and high mandibular plane angle (>40 degrees). RESULTS: The kind of osteosynthesis used was not significantly different between the 2 groups. The amount of surgical advancements and the vertical movements of the jaws were not significantly different between the 2 groups. However, the distal (P =.005) and proximal (P =.007) mandibular segments were rotated significantly further counterclockwise in group I. Surgically induced posterior condylar displacement occurred significantly more frequently (P =.007) in group I. CONCLUSIONS: Counterclockwise rotation of the distal and proximal mandibular segments and surgically induced posterior condylar displacement seem to be important surgical risk factors for postoperative condylar resorption. Therefore, these movements seem to be contraindicated in patients who are at high risk.

Diffuse chronic sclerosing osteomyelitis and the synovitis, acne, pustolosis, hyperostosis, osteitis (SAPHO) syndrome in two sisters.

Two sisters with diffuse chronic sclerosing osteomyelitis of the mandible and the humerus and the synovitis, acne, pustolosis, hyperostosis and osteitis syndrome (SAPHO syndrome) are presented. The diagnoses of diffuse chronic sclerosing osteomyelitis at the age of 12 years and 27 years, respectively, were based on typical medical history, clinical symptoms and radiographic, histologic and scintigraphic findings. Because skin lesions and scintigraphic enhancement of the sternoclavicular joints with hyperostosis were present, a SAPHO syndrome was diagnosed in both sisters. Microbiological cultures of biopsy specimens revealed coagulase-negative Staphylococcus aureus at the humerus and Haemophilus parainfluenzae, Streptococcus, Actinomyces and Veilonella species at the mandible. Repeated operative procedures, including decortications, resection and reconstruction, and multiple histologic and microbiologic studies were performed over a period of up to 20 years. Since HLA typing yielded identical gene loci, we suggest that hereditary and autoimmune factors may play a role in the pathogenesis of these cases.

Late sequelae after high midface trauma.

The upper midface area comprises mainly the naso-orbito-ethmoidal (NOE) region which plays a paramount role in facial expression. Fractures of this area often result in neglected bony defects in the fragile periorbital region with major secondary impairments such as traumatic telecanthus, orbital dystopia, and/or enophthalmos. Permanent cranial nerve deficits also can occur as the result of post-traumatic/post-operative sequelae. Seventy-one patients (age range 7-78 years) with severe high midface trauma, treated from January 1989 to December 1996, were reviewed with a minimum follow-up of 2 years. The patient population has been distributed according to the fracture type in three groups: Group 1 (n = 35): Isolated NOE with/without associated central midface injury; Group 2 (n = 22): NOE associated with craniofacial injury and Group 3 (n = 14): NOE associated with orbital displacement. The estimated post-surgical parameters included qualitative and quantitative data from the long-term clinical evaluation. Persistent headache and/or concentration difficulties were mainly noted in Group 1. Smell reduction or anosmia was reported mainly in Group 2. Deficits of the trigeminal and/or the facial nerve were found in Group 3. Enophthalmos and/or telecanthus were predominantly seen with injuries associated with orbital displacement.

Primary chronic osteomyelitis associated with synovitis, acne, pustulosis, hyperostosis and osteitis (SAPHO syndrome).

Diffuse sclerosing osteomyelitis may indicate the mandibular localisation of the SAPHO syndrome. Twelve patients with diffuse sclerosis of the mandible were examined for symptoms of the SAPHO syndrome. Nine patients were found to have primary chronic osteomyelitis and eight of these represented a SAPHO syndrome. Results in this series support the hypothesis of an association between primary chronic osteomyelitis and the SAPHO syndrome.

Alternative methods for reduction of blood loss during elective orthognathic surgery.

Bimaxillary orthognathic surgery and genioplasty are frequently performed to correct dentoskeletal anomalies in otherwise healthy young patients. Until 1990 homologous blood transfusions were routinely necessary for these procedures. The present study describes a protocol of blood-saving measures that was adopted and tested on a continuous sample of 127 patients treated between 1994 and 1997. The protocol comprises acute normovolemic hemodilution, controlled moderate hypotension, positioning the surgical field above the heart level, cell saving, intraoperative homeostasis, preoperative autologous blood donation, administration of recombinant erythropoietin, and acceptance of a low hematocrit perioperatively. This study shows that homologous blood transfusions may be avoided intraoperatively by following the protocol described.

Multimodal strategy for reduction of homologous transfusions in cranio-maxillofacial surgery.

The transfusion of homologous blood carries well-known risks that have prompted efforts to develop alternative techniques. Such measures are of particular interest to patients undergoing elective procedures. A total of 204 patients, out of 1470 patients who consecutively underwent major craniomaxillofacial procedures under general anesthesia over a two-year period, were enrolled in a prospective protocol to reduce homologous transfusion requirements when a blood loss in excess of 500 ml was anticipated. The data were compared with the results of a retrospective control group (n=2890) covering major procedures during the previous four years, when blood-saving measures were applied occasionally, but not based on a global strategy. Techniques for the reduction of homologous transfusions were acute normovolemic hemodilution, controlled moderate hypotension, cell saver and predeposit autologous blood. In addition, preoperative administration of human recombinant erythropoietin was introduced during the last year of the study. These techniques were applied individually or in combination, depending on contraindications specific for each technique, using invasive monitoring in order to maintain intraoperative hemodynamic stability. The goal of this study was to examine the extent to which homologous transfusions may be reduced with the systematic application of transfusion-sparing techniques. Of 204 patients qualifying for the transfusion-sparing protocol, 30 received homologous transfusions. In comparison to the control group, utilization of transfusion-sparing techniques had doubled. The overall reduction in the use of homologous transfusions was highly significant. When acute normovolemic hemodilution, controlled moderate hypotension and the cell saver were used in combination, a greater reduction in homologous transfusions was achieved than with the use of either a single modality or combination of any two. No transfusions were required in patients pretreated with erythropoietin.

The Le Fort I osteotomy as a surgical approach for removal of tumours of the midface.

Tumours of the midface and maxillary sinuses have been removed via multiple approaches. The most common approaches are those using incisions in the facial skin, especially in the case of malignant tumours. The Le Fort I procedure via an intraoral incision as described by Sailer in 1986 is a versatile alternative. Combined with a coronal approach and various osteotomies of the upper face it also allows removal of tumours extending into the orbits, the nasoethmoidal complex and the skull base. The versatility of the Le Fort I osteotomy as a surgical approach was analysed in 17 cases. This method is reliable and gives excellent access. Further advantages are the wide surgical exposure and the clear visibility of the resection margins, the absence of visible scars, the feasibility of combining this approach with reconstruction using the buccal fat pad and the possibility of simultaneous placement of bone grafts, insertion of endosseous implants or other preprosthetic procedures via the same incision.

Frontal sinus fractures: computed tomography evaluation of sinus obliteration with lyophilized cartilage.

Allogenic lyophilized cartilage has been proven clinically to be a reliable material for obliteration of the frontal sinus without the limitations of donor site morbidity and the prolongation of the operation time produced by autogenic grafting. The long-term behaviour of the implanted material is of paramount importance for the success of the obliterative technique. This survey included 51 trauma patients on whom obliteration of the frontal sinus with lyophilized cartilage was performed. The fate of the lyophilized cartilage graft was evaluated from computed tomography imaging of the obliterated frontal sinus. No radiological sign of mucocele formation or inflammatory disease was noted. Bone density measurement of the obliterated sinus and the adjacent trabecular bone was calculated. The patient population was distributed into four groups (0-2, 2-4, 4-6, > 6 years) according the postobliterative time. The bone density of the implanted lyophilized cartilage was accentuated from group 1 to group 4 when compared with the bone density of the trabecular bone. This shows the long-term tendency of lyophilized cartilage graft to osseous substitution.