Presentation and short-term evaluation of an all-in-one patient-specific implant for cranial reconstruction: A randomized controlled trial.

Cranial reconstruction after bone graft harvesting remains a challenge. A patient-specific implant (PSI) to guide harvesting and reconstruction was evaluated and compared with the use of a free-hand procedure with calcium phosphate cement (C). Patients were randomized to either the PSI or C group. The outcome was measured clinically and radiographically as the primary endpoint. Secondary endpoints were ease of application, patient and surgeon satisfaction, and the complication rate. Twenty patients were randomized to the PSI (n=10) and C (n=10) groups. Two PSI patients were switched to the cement group due to a poor fit of the PSI. There was a non-significant trend towards more successful outcomes in the PSI group. Two PSI patients presented palpable screws, and one cement patient had a palpable dimple. Cone beam computed tomography showed a significantly lower median volume discrepancy in the PSI group (P<0.0001). The total surgical manipulation time was significantly higher in the PSI group. At 10 days postoperative, three PSI and two C patients presented with minor postoperative complications. There was no significant difference in patient or surgeon satisfaction. PSIs are a reliable alternative to cement. This PSI is novel as it also serves as a guide for harvesting the bone blocks required for reconstructive purposes.

Long-term quality of life outcomes of maxillomandibular advancement osteotomy in patients with obstructive sleep apnoea syndrome.

This study was performed to evaluate the long-term impact of maxillomandibular advancement (MMA) surgery on the apnoea-hypopnoea index (AHI) and quality of life (QoL) in patients with obstructive sleep apnoea syndrome (OSAS). The medical files of 12 OSAS patients who underwent MMA by one surgeon between 1995 and 1999 were reviewed retrospectively. Patients received a clinical assessment, polysomnography, and QoL questionnaires as part of routine care preoperatively (n=12), within 2 years postoperative (n=12), and again in 2016 (n=9). A successful surgical outcome was defined as an AHI decrease of >50% with <20 events/h. Of the 66.7% (8/12) of patients who were initially cured, 66.7% (4/6) remained stable at a median follow-up of 19 years. Only the two patients with the highest AHI showed abnormal Epworth Sleepiness Scale scores. After convalescence, most patients reported stable symptomatic improvement. Aesthetic changes were found acceptable and all but one patient stated that they would undergo the surgery again. It is concluded that MMA is a safe and effective procedure. Ageing and weight gain might counterbalance the positive effects of surgery in the long term. It is therefore suggested that re-evaluation every 5 years should be scheduled, since a spontaneous AHI increase over time does not seem to be reflected by symptomatic changes.

Three-dimensional volumetric changes in the upper airway after maxillomandibular advancement in obstructive sleep apnoea patients and the impact on quality of life.

Obstructive sleep apnoea (OSA) is a sleep-related breathing disorder, characterized by repetitive airway obstructions, causing disruptive snoring and daytime sleepiness. Maxillomandibular advancement (MMA), which enlarges the upper airway, is a therapeutic surgical approach. However, no study has performed an upper airway sub-region analysis using validated three-dimensional (3D) anatomical and technical limits on cone beam computed tomography (CBCT). Hence, this prospective, observational trial was performed to evaluate 3D volumetric changes in the upper airway according to validated 3D cephalometric landmarks, before and after MMA, for all patients with a polysomnography diagnosis of OSA (apnoea-hypopnoea index (AHI) ≥5). The secondary objective was to evaluate the impact of MMA on the AHI and in a subjective manner with the Epworth Sleepiness Scale (ESS) and OSA questionnaire. Eleven consecutive OSA patients were included. A significant volume increase in the oropharynx (P=0.002) and hypopharynx (P=0.02) was observed, in contrast to a non-significant volume reduction in the nasopharynx (P >0.05). The median AHI (P=0.03) and ESS score (P=0.004) decreased significantly as a result of surgery. In conclusion, MMA significantly enlarges the airway volume of the oropharynx and hypopharynx and is associated with improved quality of life.

Is oestrogen associated with mandibular condylar resorption? A systematic review.

A systematic review of the literature was performed regarding the influence of oestrogen on the occurrence of mandibular condylar resorption. Search terms for oestrogen were used in combination with terms related to the effect on condylar remodelling. A search of the PubMed, Embase, and Cochrane Central Register of Controlled Trials databases yielded 419 articles published between October 1993 and March 2017. An additional 48 articles were retrieved through manual searching of the reference lists. After initial abstract selection, 94 eligible articles were screened in detail, resulting in a final number of 33 articles included in the review. From this review, no evidence was found that oestrogen (deficiency) contributes to mandibular condylar resorption. The conclusions are limited by the lack of studies with a high level of evidence. Further investigations on serum oestrogen concentrations in women with condylar resorption are needed. Moreover, future studies should focus on the effects of the different types of medication and diseases influencing oestrogen concentrations, the utility of oestrogen concentrations during preoperative screening, and the policies for managing orthognathic surgery patients with an oestrogen deficiency. Finally, whether the mechanisms and risk factors that lead to idiopathic condylar resorption are the same in condylar resorption following orthognathic surgery remain to be elucidated.

Application of a non-invasive reference headband and a surgical splint for intraoperative paediatric navigation.

The key to the success of surgical navigation based on computer-aided design and computer-aided manufacturing (CAD/CAM) planning is the registration process. This has to be precise and adapted to the surgical needs. However, the application of a conventional rigid skull-fixed navigation star for accurate registration is limited for use in the paediatric population, because of the risk of unstable fixation, dural perforation, and intracranial bleeding. The authors describe their experience with a non-invasive reference headband that was used in combination with a custom-made acrylic resin dental registration splint for resection of a rare infraorbital zygomatic desmoplastic fibroma in a 2-year old patient. This approach appears not to have been reported in the literature to date.

Free flaps and literature review.

BACKGROUND: Microvascular free flaps are a reliable and efficient method for restoring head and neck defects. Here we describe 169 free flap procedures, and determine the success rate of these reconstructions. METHODS: This study included data from all patients who underwent microsurgical reconstruction for head and neck defects at St. John's Hospital in Bruges between 1994 and 2012. We analysed sex, age, American Society of Anaesthesiologists (ASA) score, smoking, prior radiotherapy, and deep circumflex iliac artery (DCIA) harvesting technique to determine their influences on flap complications and overall complications. RESULTS: Our study included 169 free flap procedures, with a flap success rate of 92%. The rate of systemic complications was 21%. The DCIA split harvesting technique was associated with a significantly higher incidence of flap complications. Increased age (357 years) was associated with a higher incidence of overall complications. CONCLUSION: In our present series, the DCIA split harvesting technique was associated with a significantly higher frequency of total flap failure. This increased failure rate was attributed to important haematomas that compromised venous circulation. We also found that patient age was a significant factor for the development of postoperative complications.

Presentation of a cone-beam CT scanning protocol for preprosthetic cranial bone grafting of the atrophic maxilla.

The use of autologous calvarian split thickness bone grafts is a well accepted preprosthetic surgical procedure for reconstruction of the severely atrophied maxilla. Although generally accepted as being a superior bone graft regarding long-term stability, the reported risks in the literature may dissuade the surgeon. A modified cone-beam computed tomography (CBCT) scanning protocol (extended field of view starting from 1cm below the occlusal plane up to the limit of the cranial vault, 0.4 voxel) is proposed that allows assessment of both the cranial donor site as the maxillary receptor site and the sinus conditions with a single scan. Issues regarding quality of the data, radiation dose and clinical practicability are discussed.

A cone-beam CT based technique to augment the 3D virtual skull model with a detailed dental surface.

Cone-beam computed tomography (CBCT) is used for maxillofacial imaging. 3D virtual planning of orthognathic and facial orthomorphic surgery requires detailed visualisation of the interocclusal relationship. This study aimed to introduce and evaluate the use of a double CBCT scan procedure with a modified wax bite wafer to augment the 3D virtual skull model with a detailed dental surface. The impressions of the dental arches and the wax bite wafer were scanned for ten patient separately using a high resolution standardized CBCT scanning protocol. Surface-based rigid registration using ICP (iterative closest points) was used to fit the virtual models on the wax bite wafer. Automatic rigid point-based registration of the wax bite wafer on the patient scan was performed to implement the digital virtual dental arches into the patient's skull model. Probability error histograms showed errors of < or =0.22 mm (25% percentile), < or =0.44 mm (50% percentile) and < or =1.09 mm (90% percentile) for ICP surface matching. The mean registration error for automatic point-based rigid registration was 0.18+/-0.10 mm (range 0.13-0.26 mm). The results show the potential for a double CBCT scan procedure with a modified wax bite wafer to set-up a 3D virtual augmented model of the skull with detailed dental surface.

The effect of mandibular nerve block on opioid consumption, nausea and vomiting in bilateral mandibular osteotomies.

UNLABELLED: The purpose of this study was to compare the efficacy of a mandibular nerve block to placebo, in patients undergoing mandibular osteotomy surgery, regarding opioid consumption and adverse opioid induced side effects. Forty healthy individuals with a mean age of 19.7 years participated in the study. All subjects received lidocaïn 2% + adrenaline 1/80,000 versus placebo for mandibular nerve block in a randomized double-blind manner. Opioid consumption and opioid related side effect such as postoperative nausea and vomiting (PONV), and respiratory depression were assessed. RESULTS: The placebo group received significantly more sufentanil during the surgical procedure than the lidocaïngroup. There were no significant differences in adverse opioid induced side effects. In the postoperative phase there was no difference in additional pain intervention between the two groups. CONCLUSION: The mandibular block during mandibular osteotomy reduces intra-operative opioid consumption but does not alternate the opioid related side-effects in the postoperative phase.

Intraoral transmental suction lipectomy.

Intraoral transmental suction lipectomy (TMSL) is performed by entering the suction canula through the chin osteotomy/ostectomy gap into the sub- and/or supraplatysmal fat tissue layers. The aim of the study was to know patients' and operators' satisfaction with the procedure, and to know the kind and frequency of the complications. Twenty patients were consecutively treated and reviewed after a minimum of 5 years. All were satisfied with the overall results. It proved difficult to differentiate between the results of the liposuction and those of the genioplasty and/or orthognathic profile correction. From a surgeon's point of view, 11 showed excellent, nine good and one moderate results. Complications included one local subcutaneous infection, four transient neurosensory disturbances at the lower lip and two marginal branch weaknesses. All complications were resolved by the time of the long-term follow-up appointment. TMSL offers the psychological advantage of being performed without skin incision. Cosmetic results and complications are similar to those obtained with the transcutaneous liposuction techniques.

Mandibular angle augmentation with the use of distraction and homologous lyophilized cartilage in a case of morphing to Michael Jackson surgery.

Correction of an ill-defined mandibular angle is not an easy task, whether it is requested by the "congenital, orthognathic or cosmetic" patient. Deliberate over-correction has not been reported to our knowledge. This article presents a combination of distraction osteogenesis and lyophilized cartilage used to three-dimensionally over-augment the mandibular angle of a long-face prognathic patient who had the wish to be morphed to Michael Jackson or at least as far as current technique and his endogenic features allowed.

[Rehabilitation of the anterior portions of the maxilla and mandible by means of implants and bone grafts]. / Réhabilitation orale des régions antéro-inférieure et antéro-supérieure à l'aide d'implants et de greffons osseux.

This article describes the possibilities and difficulties of reconstruction in the front regio by means of implants and bone transplants in five patients. First of all, planning is the most important step. Sometimes the class III relationship is a real challenge. Different bone transplants, the inlay and onlay technique, the number of the implants, the importance of the way the implants are uncovered in the second stage are discussed. In the front region, we aim for functional and esthetic reconstruction.

[Treatment of a congenitally missing upper lateral incisor with an implant]. / Traitement de l'agénésie de l'incisive latérale supérieure au moyen d'un implant.

The presentation of a case where an agenetic lateral tooth was replaced by an oral implant, has been described. The following parameters are important: oral hygiene, the moment of implant surgery, presurgical orthodontic treatment, alternative prosthetic treatment possibilities and recall of the patient.

[Vertical augmentation of the alveolar process by distraction osteogenesis]. / Augmentation de la hauteur du procès alvéolaire par distraction osseuse.

This article describes the treatment of a boy with Class II deep bite and hypoplasia of the alveolar process due to agenesis of the canines and premolars. At first, the occlusion has been adjusted by advancement of the mandible and opening of the bite after bilateral sagittal split osteotomy. Later, under local anaesthesia, a segmental osteotomy of the hypoplastic alveolar process has been performed. Distraction of the hypoplastic alveolar process has been achieved by orthodontic traction on the residual dentition in the segments. After sufficient augmentation of the alveolar process, 6 implants for two bridges have been placed.

Nasal profile changes after maxillary impaction and advancement surgery.

PURPOSE: The profile changes in the nasal tip and columello-labial region that occur after maxillary advancement and impaction surgery were measured to test the hypothesis that a subspinal osteotomy would induce less nasal tip change and would result in a more acute columello-labial angle than a conventional Le Fort I-type osteotomy. PATIENTS AND METHODS: The lateral cephalograms of 2 matched groups of 23 advancement/impaction cases with and without subspinal osteotomy were analyzed electronically. RESULTS: There was no difference in nasal tip elevation and change in nasal tip projection between the 2 groups. The columello-labial angle was, on average, unchanged by the surgery. A linear correlation with a weak clinical relevance could be demonstrated between nasal tip projection and maxillary advancement in the group that was treated without subspinal osteotomy. Such a correlation was not detected for nasal tip elevation in either of the groups. Palatal plane rotation had a significant influence on nasal tip projection but not on tip elevation in both groups. The correlation was strongest in the group treated conventionally. The multiple regression equation with maxillary advancement and rotation as predictors had a r2 of .6071 (nasal tip projection = 0.9 + 0.19 maxillary advancement + 0.18 palatal plane inclination) in this group. CONCLUSION: The results indicate that the advancing piriform aperture pushing on the alae, and not the nasal spine, is responsible for the increase in nasal tip projection. The subspinal osteotomy is not superior to the conventional Le Fort I-type osteotomy in regard to minimizing nasal tip changes and obtaining control over the columello-labial angle.

Six year's experience with the zygomatic "sandwich" osteotomy for correction of malar deficiency.

PURPOSE: This study discusses the rationale, modifications, and complications of an osteotomy technique used to increase malar projection. PATIENTS AND METHODS: Seventy "sandwich" zygomatic osteotomies were performed in a 6-year period. Hydroxyapatite (HA) blocks were used to stabilize the anterolateral rotation of the zygomatic body in 44 osteotomies, calcium carbonate blocks were used in 23, calvarial bone grafts in three, a piece of bovine cartilage in one, and a bone graft from a chin ostectomy procedure combined with mesh osteosynthesis in one procedure. Fifty-six zygomatic osteotomies were combined with Le Fort I-type osteotomies (eight with a midline split). Nineteen zygomatic osteotomies were performed simultaneously with a Le Fort I-type osteotomy and a rhinoplasty with lateral osteotomies. RESULTS: The increase of malar projection and the stability of the procedure could not be measured on conventional three-plane cephalograms. However, patient's and surgeon's satisfaction were high and remained so during the follow-up period (maximum, 6.5 years; minimum, 6 months). Three patients developed maxillary sinusitis. In two of them, this was clearly related to fragmentation of an HA block. A Treacher-Collins patient developed a chronic fistula in the upper vestibule, caused by leakage of infraorbitally placed HA granules. In two cases, a fracture of the zygomatic arch occurred. Osteosynthesis was performed in one of them. CONCLUSION: With proper technique and care not to fracture the interpositional HA block, complications are rare. The procedure is expedient and provides predictable and stable correction of malar deficiency.

Proximal segment position after distraction with the MD-DOS device.

We investigated cephalometrically the movement of the proximal segment in the sagittal plane in patients treated with distraction (MD-DOS device) for mandibular lengthening. The proximal segment was anteriorly rotated, whilst the distal segment was posteriorly rotated after the lengthening procedure. Thus the angle of the jaw was advanced half the distance of the advancement of the distal segment. One possible reason for the anterior rotation of 3.3 degrees on average is the repositioning of the proximal segment during application of the anterior fixation unit in the cases where mobilization was complete. Another more plausible reason is the anterior pull by the masticatory muscles and elastic bands being greater than the reactive distraction vector component in concert with a flexible telescopic distraction module and a single posterior screw anchorage. The positional movements of both distal and proximal segments were similar to those observed after mandibular advancement with bilateral sagittal split osteotomies.

The nasal frame osteotomy: technical note.

In the practice of orthognathic surgery, a patient presenting with a gummy smile and lip incompetence is readily diagnosed as having vertical maxillary excess, and a maxillary impaction osteotomy is usually the proposed treatment. If a short nose, an arched and upwardly displaced upper lip, and a broad face accompany these 2 features, nasal lengthening and caudal repositioning of the central portion of the upper lip by a nasal frame osteotomy should be considered instead. The technique of the nasal "frame" osteotomy, which was used in 1 patient with a 4-year follow-up, is described.

Prediction of mandibular autorotation.

PURPOSE: The purpose of this investigation was to test the hypothesis that the mandible rotates around the same point during maxillary impaction surgery as during initial jaw opening. This point, called the center of mandibular autorotation (CAR), could then be used to predict mandibular position and to decide whether only maxillary impaction would be needed to correct the occlusion and the facial profile. PATIENTS AND METHODS: Preoperatively, two lateral cephalograms were obtained from a consecutive series of 20 patients who underwent maxillary impaction without concomitant mandibular ramus osteotomy. One cephalogram was taken with the mandible in centric relation using a wax bite wafer and another with a jaw opening of 10 mm using a fabricated acrylic bite block with the mandible manipulated to its most retruded position. The CAR was calculated before and after jaw opening using the Rouleaux method on the lower incisor and gonion point. A third lateral cephalogram was taken within 2 days postoperatively. The postoperative lower incisal point was then transferred to the first cephalogram using cranial base superimposition. RESULTS: When the preoperative and postoperative distances between CAR and incisal point were compared, there was no significant difference between these distances, proving the hypothesis. CONCLUSIONS: The method used is a practical and precise way to determine the center of mandibular autorotation on an individual basis. The center of rotation during initial jaw opening is the same as during impaction surgery.