Follow up of surgically-assisted rapid maxillary expansion after 6.5 years: skeletal and dental effects.

Surgically-assisted rapid maxillary expansion (SARME) is a technique used to widen the maxilla, and we present the results of our long-term follow up (6.5 years). Seventeen patients who had been treated with SARME and prospectively followed were invited for long-term follow up using dental casts and posteroanterior cephalograms. The following measurements were made on the dental casts: transverse distances at canine, premolar, and molar level, length of the arch, and width and depth of the palate at premolar and molar level. The distance between the left and right nasal bases and the widening of the inferior maxilla were measured on the posteroanterior cephalograms. Boneborne and toothborne distractors were used in 8 and 9 patients, respectively. In the study of dental casts, there was a significant increase in transverse width in the canine (P<0.001), premolar (P<0.001) and molar (P=0,001) and these remained stable in the long term. The arch length did not increase significantly, but the palatal width increased significantly in the premolar (P<0.001) and molar (P=0.001) regions. No effect was seen in palatal depth. On the posteroanterior cephalograms the width of the inferior part of the maxilla was increased, but not significantly so. There were no significant changes at the nasal base. We conclude that SARME is a predictable technique to widen the maxilla in the long term.

Long-term (6.5 years) follow-up of mandibular midline distraction.

To assess the long-term stability and biomechanical effects of mandibular midline distraction (MMD), a prospective observational study was conducted with a retrospective cohort. Included were 17 MMD patients, of whom 9 completed the long-term follow-up with a mean of 6.5 years. In all patients, a bone-borne distractor was used. Dental casts and postero-anterior (PA) cephalograms were taken at fixed time points: pre-operative (T1), directly post-distraction (T2), 1-year post-operative (T3) and long-term follow-up (T4). Inter canine (ICD), inter first premolar (IPMD), inter first molar (IMD) distances and arch length (AL) were measured on dental casts. From the PA cephalograms intercondyle distance (ID) and the ramal angle (RA) were obtained. A significant and sustained widening was observed in most measurements. The greatest overall transverse expansion (T1-T4) occurred in the IPMD (4.1 ± 0.76 mm, P < 0.05), the ICD, IMD and AL increased, respectively: 2.0 ± 0.72 mm, 3.8 ± 0.82 mm and 3.5 ± 0.82 mm. The ID did not change significant (P > 0.05) during all phases of the study. An increase of RA was observed initially; however, no difference was noted in the long-term. This study showed that MMD is a stable method to expand the mandible, with no skeletal effect on the temporomandibular joint.

Pure orbital blowout fractures reconstructed with autogenous bone grafts: functional and aesthetic outcomes.

The purpose of this study was to investigate the ophthalmic clinical findings following surgical reconstruction with autogenous bone grafts of pure blowout fractures. A retrospective review of 211 patients who underwent surgical repair of an orbital fracture between October 1996 and December 2013 was performed. Following data analysis, 60 patients who were followed up over a period of 1 year were included. A solitary floor fracture was present in 38 patients and a floor and a medial wall fracture in 22 patients. Comparing preoperative findings between these two groups, preoperative diplopia and enophthalmos were almost twice as frequent in the group with additional medial wall fractures: diplopia 8% and 14% and enophthalmos 18% and 55%, respectively. One year following surgery there was no diplopia present in either group. In the solitary floor fracture group, 3% still had enophthalmos. It can be concluded that at 1 year following the repair of pure orbital floor fractures using autogenous bone, good functional and aesthetic results can be obtained. In the group with both floor and medial wall fractures, no enophthalmos was found when both walls were reconstructed. When the medial wall was left unoperated, 29% of patients still suffered from enophthalmos after 1 year.

Effects of hyperbaric oxygen therapy on the viability of irradiated soft head and neck tissues in mice.

OBJECTIVES: Hyperbaric oxygen therapy (HBOT) is used clinically in irradiation-induced injury to healthy tissues, but the effectiveness and working mechanism remain unclear. This study examined the effects of HBOT on irradiated salivary glands and tongue in a mouse model. MATERIALS AND METHODS: Mice were irradiated with a single dose (15 Gy) in the head and neck region and subjected to HBOT, either before or after irradiation. During the course of the treatments, salivary flow rates were measured and at different time points after radiation (2, 6, 10 and 24 weeks), salivary glands and tongue were harvested and (immuno) histochemically analysed. RESULTS: Proliferation and blood vessel density in salivary glands were enhanced by HBOT in the medium term (10 weeks after irradiation), while salivary flow rates were not influenced. In the long term, irradiation-induced proliferation in the muscle tissue of the tongue was decreased by HBOT. CONCLUSION: Hyperbaric oxygen therapy (HBOT) appears to stimulate regeneration or protection of salivary gland tissue following radiation therapy. Possible implications of the effect of HBOT on muscle tissue of the tongue for the prevention of dysphagia and trismus are discussed. This study provides insights on the cellular changes after HBOT and encourages further research on this topic to achieve a better implementation of the therapy in humans.

Influence of pharyngeal flap surgery on maxillary outgrowth in cleft patients.

The aim of this study was to investigate the influence of the pharyngeal flap procedure on the frequency of Le Fort I osteotomies in full-grown nonsyndromic cleft patients. A retrospective review of 508 full-grown cleft patients born between 1 January 1983 and 31 December 1992 was performed. Following data analysis, 140 males older than 18 years and 111 females over the age of 16 years were included. 69 of the 251 included cleft patients required pharyngeal flap surgery (27.5%). Revision flap surgery was performed in 17.4% of the cases. A significantly lower age at time of the initial pharyngeal flap procedure was found in patients requiring revision surgery (5.6 years versus 6.8 years). The frequency of Le Fort I osteotomies was significantly higher in the patients with a pharyngeal flap (19%) compared to those without (8%) (p<0.05). The results of this study point towards the pharyngeal flap procedure being one of the possible limiting factors for maxillary antero-posterior growth in cleft patients.

Osteoradionecrosis of the external auditory canal: three cases involving reconstruction with transposition of a split temporalis muscle flap.

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.

Surgical treatment of frontal sinus fractures: the simple percutaneous reduction revised.

Frontal sinus fractures are common fractures in high-energetic trauma. Different treatments options are available for different types of frontal sinus fractures. A fracture that consists only of the anterior wall is most commonly reduced with the coronal approach. This approach is invasive and produces a large scar on the scalp, which can result in an unfavourable situation in patients with alopecia and in balding men. To avoid this, a percutaneous reduction method can be used to treat patients with simple anterior wall fractures. This approach is less invasive and does not result in a conspicuous scar. The disadvantages of this procedure are the absence of direct vision and less control of the fracture, which can reduce the chances of complete reduction. This paper provides an overview of anterior wall fractures of the frontal sinus and elaborates on the simple percutaneous reduction technique.

Open reduction versus endoscopically controlled reconstruction of orbital floor fractures: a retrospective analysis.

The aim of this study was to compare the postoperative results of open reduction versus endoscopically controlled reconstructions of orbital floor fractures. The medical records of 83 patients, treated between January 2000 and December 2008, were reviewed for enophthalmos, diplopia and complications. Fifty-eight patients were operated on using open reduction and in 25 patients the open reduction was endoscopically controlled. A significantly better outcome, regarding enophthalmos and diplopia improvement, was found in the endoscopically controlled group. Endoscopically controlled reconstruction of orbital floor fractures seems to be a more accurate and successful treatment.

Custom-made intraoral mandibular distraction as treatment for neonatal airway obstruction.

Hypoplastic mandible related airway obstruction therapy may vary from non-surgical to surgical, depending on the severity of the obstruction. Since its introduction in 1992, distraction osteogenesis (DO) has been used to lengthen the mandible. A new intraoral device is presented here. It has no need of screw fixation, whilst placement and activation are intraoral, leading to simple placement and removal. Seven cases with hypoplastic mandible related airway obstruction were treated between 2001 and 2008 with intraoral DO at the authors' institution. Six patients had a tracheostomy and one received continuous positive airway pressure (CPAP). After the distraction phase, five patients could be decanulated and in one case CPAP was no longer required. In one case the desired effect was not achieved. The findings suggest that early mandibular DO leads to damage to the permanent tooth buds resulting in missing teeth. The effectiveness of mandibular DO regarding early discharge of the patient is shown, leading to an overall cost reduction. Knowledge of alternative modalities such as mandibular DO in case of hypoplastic mandible related airway obstruction in neonatal healthcare should lead to early referral to a dedicated maxillofacial surgeon, possibly avoiding long-term airway support or tracheotomy.

A hyperbaric oxygen chamber for animal experimental purposes.

Facilities for hyperbaric oxygen therapy that are suitable for animal experimental research are scarce. In this paper, the authors introduce a hyperbaric oxygen chamber that was developed specifically for animal experimental purposes. The hyperbaric oxygen chamber was designed to meet a number of criteria regarding safety and ease of use. The hyperbaric oxygen chamber conforms to 97/23/EC (Pressure Equipment Directive), Conformity Assessment Module G Product Group 1. It provides easy access, and can be run in manual mode, semi-automatic mode and full-automatic mode. Sensors for pressure level, oxygen level, temperature, humidity and carbon dioxide level allow full control. This state-of-the-art hyperbaric oxygen chamber for animal experimental purposes permits the investigation of the biological mechanisms through which hyperbaric oxygen therapy acts at a fundamental level.

The frequency of Le Fort I osteotomy in cleft patients.

OBJECTIVE: The aim of this research was to study the frequency of Le Fort I osteotomy (LFI) in cleft patients treated according to the protocol of the Erasmus University Medical Center, Rotterdam. DESIGN: Retrospective cohort study. Patients : 508 cleft patients born between January 1, 1983, and December 31, 1992, were evaluated. MAIN OUTCOME MEASURES: Frequency of LFI and correlations with type and extent of cleft, gender, number of previous surgical procedures, age during alveolar augmentation, and missing teeth, respectively. RESULTS: 251 patients met the inclusion criteria. Overall, 28 of the 251 patients (11.2%) required LFI: none for cleft lip (0.0%); 2 of 43 (4.7%) for cleft lip and alveolus; 24 of 100 (24.0%) for cleft lip, alveolus, and palate; 2 of 50 (4.0%) for cleft palate; and none for submucous clefts or the miscellaneous group (0.0%). The frequency of LFI increased with the severity of the cleft type. The number of previous surgical interventions is significantly higher in cases with an indication for LFI (p < .001). The frequency of LFI is significantly higher in male cleft patients (p < .05). CONCLUSIONS: The overall frequency of LFI in the study group was 11.2%; this increased with the severity of the cleft type. A significant difference was noted in the number of previous surgical interventions between patients with and without an indication for an LFI. Delayed closure of the hard palate in the protocol might have influenced the low frequency of LFI.

Introduction of the "Rotterdam mandibular distractor" and a biomechanical skull analysis of mandibular midline distraction.

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.

Assessment of volumetric changes with a best-fit method in three-dimensional stereophotograms.

OBJECTIVE: Different three-dimensional stereophotogrammetry systems and analyzing methods exist that often use landmarks for comparison. Measurement errors in landmark or surface comparison are mostly within 1 mm, which seems clinically acceptable. The aim of this study was to validate a three-dimensional stereophotogrammetric best-fit method of assessing volumetric changes and to compare three devices. METHODS: The validation of the best-fit method was at first done on a life-size dummy head. Scans were made in the ideal position, as well as in four additional positions, and a scan was made in which a soft putty specimen was added to the dummy head. The comparison was executed with a best-fit method using triangulation. Student's t tests were used to detect statistically significant differences. Second, comparisons were made among scans of a white man in the ideal position and with volume changes added. RESULTS: The different positions tested for the dummy head showed no significant volume differences within each system or among systems. The differences found when adding a soft putty specimen fell into the same range as the differences between various positions. The differences within a live situation were 10 times greater compared with the dummy-head situation. CONCLUSIONS: In a dummy-head situation, the different systems gave similar results when tested with a best-fit method. However, in live situations the differences may become 10 times greater, possibly due to different facial expressions. These differences may become clinically relevant and, therefore, further research in volumetric changes is needed.

Mandibular midline distraction: a systematic review.

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.

Additional orthognathic surgery following Le Fort III and monobloc advancement.

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.

[Management for displacement of a tooth into the floor of the mouth]. / Handelen bij een wortelrest in de mondbodem.

Displacement of a (part of a) radix or in some cases a part of a tooth into the floor of the mouth can occur during the extraction of a tooth in the mandibula. Possible causes of this are a lingual perforation of the radices or an inappropriate surgical technique. Leaving a fragment in situ in the floor of the mouth can lead to pain, swelling and trismus as a result of infection and/or spontaneous displacement of the fragment. We advise that the tooth or radix be removed as soon as possible. When experience is lacking in the removal of a tooth or radix from the floor of the mouth it is sensible to refer the patient to an oral surgeon. We also advise prescribing antibiotics in order to prevent infection.

Histomorphometric comparison between continuous and discontinuous distraction osteogenesis.

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.

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.

[Distraction osteogenesis in patients with craniofacial anomalies]. / Distractieosteogenese bij patiënten met craniofaciale anomalieën.

A cleft lip and palate is the most common congenital anomaly in the craniofacial region. There are many other congenital craniofacial anomalies. These anomalies may be part of a syndrome with a wide variety of expression. Some of these syndromes are characterized by hypoplasia of the mandible or by hypoplasia of the maxilla and the orbits, often in combination with premature closure of the skull sutures. In addition, posttraumatic and tumour resection defects are also classified as craniofacial anomalies. The care for patients with craniofacial anomalies is highly complex and, therefore, organised in multidisciplinary craniofacial teams. Some craniofacial anomalies treated by distraction osteogenesis are mandibular hypoplasia due to hemifacial microsomia or temporomandibular joint ankylosis, and mid facial hypoplasia due to craniosynostosis.

Rabbits as a model for research into craniofacial distraction osteogenesis.

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.