Predicted versus executed surgical orthognathic treatment.

OBJECTIVES: This study aimed to analyse combined surgical-orthodontic treatment plans, compare them with the actual surgery performed, and define factors resulting in changes of the original plan during orthodontic pre-surgical preparation. STUDY DESIGN: The clinical files of 312 orthognathic surgery patients, operated between January 2008 and December 2010, were retrospectively reviewed. Of these 312 patients, 129 had a bimaxillary operation. One hundred sixty patients had osteotomy of the lower jaw only and 23 had osteotomy of the upper jaw only. Factors analysed in the study include Angle Class malocclusion, patient sex, and age. Lip-to-incisor relationship, overjet, overbite and midline deviations of the upper and lower jaw were recorded. Effects of surgical assisted rapid palatal expansion (SARPE) on the eventual surgery were also investigated. Reasons for changing the original treatment plan at the time of the finished pre-surgical-orthodontic alignment were analysed. RESULTS: The original treatment plan was changed in 42 of the 312 patients (13.5%). Changes occurred generally in case of a larger interval between set-up of the first treatment plan and the eventual operation (average 22.4 versus 16.4 months for patients with changed versus unchanged treatment plan, respectively). All Class I patients had surgery performed as planned. Class III patients had a significantly higher rate of altered treatment plan (27.3%) than Class II patients (7.6%). More men (52.4%) saw their treatment plan changed, although there were more women than men in the study population (59.6 versus 40.4%). CONCLUSION: One in seven patients (13.5%) had a different operation than was planned at the start of treatment. Class III patients with small overjet and overbite commonly have a treatment plan for a monomaxillary operation that, after decompensation, needs to be adapted to a bimaxillary operation.

CBCT-based predictability of attachment of the neurovascular bundle to the proximal segment of the mandible during sagittal split osteotomy.

Injury to the inferior alveolar nerve (IAN) during surgery is an important complication of bilateral sagittal split osteotomy. With cone beam computed tomography, the course of the nerve and its relationship to the surrounding structures can be assessed in three dimensions. This study aims to determine whether tomography can predict attachment of the neurovascular bundle to the proximal segment of the mandible during sagittal split osteotomy (SSO). Bilateral linear measurements were taken on cross-sectional tomography images. During osteotomy, it was noted for each patient whether the neurovascular bundle was attached to the proximal segment during the split. If attached, a bone-cutting instrument or a blunt instrument was needed to free the nerve. The nerve was attached at more than one-third of operation sites (170 sites). Of these, over 65% of attached nerves (108 sites) required a bone-cutting intervention to free them from the mandible. After correcting for confounding factors, the linear distances from the buccal cortical margin of the IAN canal to the inner and outer buccal cortical margins of the mandible were important predictors of whether the IAN will be attached to the proximal segment of the mandible during SSO.

Lateral cephalometry changes after SARPE.

Surgically assisted rapid palatal expansion (SARPE) is associated with postoperative cephalometric changes. In this study we analyse these changes in the sagittal plane in orthognathic patients undergoing SARPE followed by orthodontic treatment and Le Fort I, bilateral sagittal split osteotomy (BSSO), or bimaxillary surgery. This is a retrospective review of 50 patients (20 males, 30 females) undergoing orthognathic treatment with SARPE to correct transversal deficiency of the maxilla as part of a comprehensive treatment plan. PP-SN, SNA, and ANB angles were increased and U1-SN and U1-PP angles were decreased. All changes were statistically significant. Changes of SNB, PP-Mand plane angle, and SN-Mand. plane angle were not statistically significant. Surgically assisted rapid palatal expansion using a bone-borne appliance as a preparative step for later orthognathic surgery results in clockwise rotation of the maxilla.

Long-term success and survival rates of autogenously transplanted canines.

OBJECTIVES: The objectives of this study were to determine the long-term survival and success rates of autotransplanted canines and to investigate the influence of various parameters on the long-term success rate. STUDY DESIGN: Fifty-nine patients (73 transplanted canines) volunteered to participate in this study. The mean follow-up time was 11 years. Different parameters that could influence the outcome of transplantation were examined in the patient files. Each transplanted canine was clinically and radiologically evaluated. Logistic regression analyses were performed. RESULTS: The survival rate was 75.3%, because 18 transplanted teeth were lost before examination. The success rate for all transplanted teeth was 57.5%, because 42 transplanted teeth were evaluated as clinically successful. The most significant parameter in determining the success rate of autotransplantation was age at transplantation (P = .0429). CONCLUSION: Autotransplantation of impacted canines may have a successful outcome 11 years after transplantation. The success rate increases when performing the transplantation at a younger age.

Development of a clinically applicable tool for bone density assessment.

OBJECTIVES: To assess the accuracy and reliability of new software for radiodensitometric evaluations. METHODS: A densitometric tool developed by MevisLab was used in conjunction with intraoral radiographs of the premolar region in both in vivo and laboratory settings. An aluminum step wedge was utilized for comparison of grey values. After computer-aided segmentation, the interproximal bone between the premolars was assessed in order to determine the mean grey value intensity of this region and convert it to a thickness in aluminum. Evaluation of the tool was determined using bone mineral density (BMD) values derived from decalcified human bone specimens as a reference standard. In vivo BMD data was collected from 35 patients as determined with dual X-ray absorptiometry (DXA). The intra and interobserver reliability of this method was assessed by Bland and Altman Plots to determine the precision of this tool. RESULTS: In the laboratory study, the threshold value for detection of bone loss was 6.5%. The densitometric data (mm Al eq.) was highly correlated with the jaw bone BMD, as determined using dual X-ray absorptiometry (r = 0.96). For the in vivo study, the correlations between the mm Al equivalent of the average upper and lower jaw with the lumbar spine BMD, total hip BMD and femoral neck BMD were 0.489, 0.537 and 0.467, respectively (P < 0.05). For the intraobserver reliability, a Bland and Altman plot showed that the mean difference +/- 1.96 SD were within +/-0.15 mm Al eq. with the mean difference value small than 0.003 mm Al eq. For the interobserver reliability, the mean difference +/-1.96 SD were within +/-0.11 mm Al eq. with the mean difference of 0.008 mm Al eq. CONCLUSIONS: A densitometric software tool has been developed, that is reliable for bone density assessment. It now requires further investigation to evaluate its accuracy and clinical applicability in large scale studies.

Image-based planning and clinical validation of zygoma and pterygoid implant placement in patients with severe bone atrophy using customized drill guides. Preliminary results from a prospective clinical follow-up study.

The zygoma implant has been designed for those situations where there is insufficient bone in the upper jaw, which would otherwise require onlay or inlay (sinus) bonegrafts. The aim of the study was to present and validate a planning system for implant insertion based on preoperative CT imaging. It allows the surgeon to determine the desired position of different kinds of implants. Finally a customized drill guide is produced by stereolithography. In this study, zygoma, pterygoid and regular platform implants were used. The treatment protocol is validated through 12 case studies, selected at random from the total patient group (n=29 patients). From postoperative images, the exact implant location is determined and the deviation of axes between planned and inserted implants is calculated. In this in vivo study, displacements, varying according to the type of implant and the location of the implants, were observed. From a clinical standpoint, most of the inserted implants were judged to be adequately sited. A prospective clinical follow-up study was performed on all 29 patients. Although all patients presented with severe maxillary atrophy, excellent cumulative survival rates (92%) for the zygoma implants and 93% for regular platform implants have been obtained.

Three-year evaluation of Brånemark implants connected to angulated abutments.

A 3-year multicenter study on 63 maxillary and 10 mandibular fixed prostheses in 71 patients is reported. Angulated abutments or a combination of angulated and standard abutments were used to support prostheses; all components were from the Brånemark System. Of 425 implants initially placed, 4 were lost before abutment connection. Of the remaining 421 implants, 209 angulated (test) abutments and 212 standard (control) abutments were placed to support fixed prostheses. The prosthesis success rates were 96.8% for maxillae and 100% for mandibles. A total of 5.3% of the loaded test implants and 7.5% of the loaded control implants failed. The survival rates after 3 years were 91.3% for maxillary control implants, 94.8% for maxillary test implants, 97.4% for mandibular control implants, and 94.1% for mandibular test implants. The findings in this study pointed out that angulated abutments will not necessarily promote peri-implant mucosal problems. The study indicated that angulated abutments on Brånemark System implants have exhibited good preliminary results and should be comparable to the standard abutment as a predictable modality in prosthetic rehabilitation.

Cryopreservation of teeth. Organizational aspects of a tissue bank for tooth tissues.

Cryopreservation of teeth became possible since a better understanding of the cryoprotective mechanism of cosolvents such as dimethylsulfoxide (DMSO). The high number of extractions of healthy teeth performed for orthodontic reasons, i.a., gives a sufficient amount of donor teeth. The organization and quality control of a tissue bank for teeth tissues is legally regulated. This paper highlights some of the key-issues of these stipulations.

Carcinoma of the oral cavity in patients over 75 years of age.

The results have been analyzed of a 15-year retrospective study on the presentation and survival of 46 patients aged > or = 75 years with oral carcinoma. All tumors were staged according to the UICC criteria. The presence of other malignant tumors in nine, premalignancy in five, and systemic disease in 15 patients was noted. A large subpopulation of elderly women, nonusers of alcohol and tobacco, usually with advanced disease, was found. In one-quarter of the patients who underwent surgery, a major resection with primary flap reconstruction was judged to be necessary. In general, this type of surgery was well tolerated. Three-year survival was 60%; women, systemically compromised patients, and patients with stage III and IV tumors did worse. A recurrence ratio of 59% was found after 5 years, recurrence usually appearing during the first year. The conversion rate was low (8.5%).

[Microsurgical reconstruction of the irradiated mandible with deep iliac circumflex flap]. / La reconstruction microchirurgicale de la mandibule irradiée par le lambeau circonflexe iliaque profond.

From 1979 to 1988, 30 osteomuscular or osteomyocutaneous free flaps of the iliac crest (revascularized by the deep circumflex pedicle) were used to reconstruct 28 mandibles severely compromised by radiotherapy exceeding 66 Grays. In addition to a perfect graft raising and microsurgical technique, perfect closure of the mucosal plane appears to be an essential factor of success. Over the years, this iliac crest flap appears to improve the radiological appearance of the bone stumps on either side. The procedure therefore appears to be particularly useful in the treatment of advanced radiation osteonecrosis.

[Pectoralis major myocutaneous island flap for cervicofacial reconstruction: a 9-year experience]. / De pectoralis major myocutane eiland lap voor cervico-faciale reconstructies: een ervaring van negen jaar.

The Pectoralis major island flap for cervico-facial reconstructions: a nine year experience. The pectoralis major m.c. flap was used for the restoration of post-tumorectomy defects in 220 patients (n = 224). 181 flaps were used for internal and 43 for external reconstructions. The overall failure rate was 9% (2.7% partial failures and 6.4% total failures). The causes which led to partial or total necrosis of a flap are analyzed. The results are compared to those of the literature. It is concluded that the above mentioned is a versatile flap in cervico-facial reconstructive surgery with a high success rate provided certain basic principles are respected during dissection and during the early postoperative period.

Craniofacial resection for anterior skull base tumours.

This study presents a series of 10 patients with anterior skull base tumours, treated by a team of neurosurgeons and head- and neck surgeons. The series included 7 malignant tumours of the nose and paranasal sinuses and 1 retinoblastoma, all with intracranial extension through the lamina cribrosa. There were also 2 patients with an anterior base meningioma, growing into the ethmoid sinus and the nasal cavity. 8 tumours were resected by a combined bifrontal craniotomy and uni- or bilateral rhinotomy. In 2 cases a bifrontal craniotomy alone without facial incision sufficed. The skull base was closed with a pediculated pericranial flap and a split-thickness free skin graft underneath. There were no postoperative problems of wound infection, CSF-leakage or meningitis. Recurrent tumour growth or systemic metastasis occurred in 5 out of 7 patients with malignant tumours, 6 months to 2 years postoperatively. The related literature and especially questions of operative indications and technique, including different possibilities of closure and reconstruction of the skull base, are discussed.

The role of CT in the diagnosis of adenocarcinoma of the ethmoid.

A retrospective study of 26 patients with ethmoid adenocarcinoma is presented. CT proves to be of great diagnostic value in demonstrating the location and extension of these tumors. The only interpretation problem that may exist is the overestimation of the tumor extension due to the occurrence of retro-obstructive sinusitis.

The significance of perineural spread in adenoid cystic carcinoma of the major and minor salivary glands.

Patient survival, local recurrence and distant metastasis were studied in relation to the pathological finding of perineural spread in 37 patients with adenoid cystic carcinoma of the major and minor salivary glands. All patients underwent a combined surgical and radiotherapeutical treatment. The overall incidence of perineural invasion in primary resection specimens was 52.6%. The 5-year actuarial survival rate for patients with perineural invasion was significantly lower (p less than 0.001) than for those without (36.9% versus 93.8%). In 26 patients with resection margins free of tumour, recurrences developed in 9/11 (81.8%) of the patients with perineural invasion as opposed to 4/15 (26.7%) of the patients without perineural invasion (p = 0.005). In the same group with resection margins free of tumour, distant metastasis developed after the primary treatment in 4/10 (40.0%) of the patients with perineural invasion, while none of the 14 patients without perineural invasion experienced distant metastasis (p less than 0.0002). The incidence of perineural invasion increased with a higher stage of the primary tumour.

Sicca syndrome with iron deposition in the salivary glands.

A case of iron deposition in the labial accessory salivary glands associated with prominent xerostomy and xerophtalmy is reported. Suffering from a myelodysplastic syndrome with refractory anaemia, this patient received multiple transfusions over the past 7 years. A transfusional haemosiderosis gradually developed. Histopathologic examination of accessory salivary glands demonstrated haemosiderin deposition in the serous alveoli and in the epithelial cells of intercalated and interlobular ducts. A relationship between the iron deposition in the salivary glands and the development of the sicca syndrome is suggested. The literature related to iron deposition in salivary glands and sicca syndrome is reviewed.