Gwen R. J. Swennen

Three-Dimensional Treatment Planning of Orthognathic Surgery in the Era of Virtual Imaging

PURPOSE The aim of this report was to present an integrated 3-dimensional (3D) virtual approach toward cone-beam computed tomography-based treatment planning of orthognathic surgery in the clinical routine. MATERIALS AND METHODS We have described the different stages of the workflow process for routine 3D virtual treatment planning of orthognathic surgery: 1) image acquisition for 3D virtual orthognathic surgery; 2) processing of acquired image data toward a 3D virtual augmented model of the patients head; 3) 3D virtual diagnosis of the patient; 4) 3D virtual treatment planning of orthognathic surgery; 5) 3D virtual treatment planning communication; 6) 3D splint manufacturing; 7) 3D virtual treatment planning transfer to the operating room; and 8) 3D virtual treatment outcome evaluation. CONCLUSIONS The potential benefits and actual limits of an integrated 3D virtual approach for the treatment of the patient with a maxillofacial deformity are discussed comprehensively from our experience using 3D virtual treatment planning clinically.

Intra- and perioperative complications of the LeFort I osteotomy: a prospective evaluation of 1000 patients.

The LeFort I osteotomy has become a routine procedure in elective orthognathic surgery. The authors report the occurrence of intra- or perioperative complications in a series of 1000 consecutive LeFort I osteotomies performed within a 20-year period. In total, 64 (6.4%) patients experienced complications. Anatomical complications affected 26 (2.6%), patients, including 16 (1.6%) with a deviation of the nasal septum and 10 (1.0%) with non-union of the osteotomy gap. Extensive bleeding that required blood transfusion occurred in 11 (1.1%) patients exclusively after bimaxillary corrections; in 1 patient a ligation of the external carotid artery became necessary. Significant infections such as abscesses or maxillary sinusitis occurred in 11 (1.1%) patients. No patient experienced an osteomyelitis. Ischemic complications affected 10 (1.0%) patients, including 2 (0.2%) who experienced an aseptic necrosis of the alveolar process and 8 (0.8%) who, under critical revision, were affected by retractions of the gingiva. Five (0.5%) patients experienced an insufficient fixation of the osteosynthesis material. The risk and the extent of complications was enhanced in patients with anatomical irregularities (eg, in patients with craniofacial dysplasias, orofacial clefts, or vascular anomalies). The risk of ischemic complications was enhanced in extensive dislocations or transversal segmentation of the maxilla. The authors conclude that patients with major anatomical irregularities should be informed about an enhanced risk of Le-Fort I osteotomies. Preoperative planning avoiding transversal segmentation or extensive dislocations of the maxilla should reduce the occurrence of complications. For healthy individuals, the risk of complications with the LeFort I osteotomy is considered low.

Maxillary distraction in cleft lip palate patients: a review of six cases.

Cleft lip and palate patients can present with a maxillary retrusion with tendency to Class III malocclusion after cleft repair. Maxillary distraction osteogenesis is a technique that provides simultaneous skeletal advancement and expansion of the soft tissues. Six nonsyndromic cleft lip and palate patients, ages 12 to 16 years (mean, 13.8 years), underwent maxillary distraction; four had a unilateral and two a bilateral cleft lip and palate. After an incomplete LeFort I osteotomy; a latency period of 3 days was respected. On Postoperative Day 4, distraction was initiated through anterior traction on a Delaire facial mask using distraction forces of 900 gm. Photographs and lateral cephalometric radiographs were obtained preoperatively and 4 months after distraction. A cephalometric analysis was performed to compare the sagittal dentocraniofacial morphology before and after distraction. The aesthetic improvement obtained by maxillary distraction osteogenesis during the permanent dentition to correct maxillary retrusion in our cleft lip and palate patients was impressive. Skeletal advancement varying from 1 to 3.5 mm (mean, 1.7 mm) was found. However, significant dentoalveolar compensations occurred in three patients. This was due to the dental anchorage of the distraction device and can be avoided only by the use of skeletal fixation.

Maxillary distraction osteogenesis: a method with skeletal anchorage.

Maxillary distraction osteogenesis is a challenging technique to treat severe maxillary retrusion. Maxillary advancement by distraction has the advantage to provide new bone in combination with simultaneous expansion of the soft-tissue functional matrix. Cleft lip and palate patients can present with severe maxillary retrusion and Class III malocclusion. Two 13-year-old patients, born with non-syndromic cleft lip and palate, underwent maxillary distraction--one had a bilateral, the other a unilateral complete cleft lip and palate. Maxillary advancement was performed using an external distraction device in combination with titanium miniplates as a skeletal maxillary anchorage. After a complete Lefort I osteotomy with pterygomaxillary disjunction, a latency period of 3 days was respected. On the fourth postoperative day, distraction was initiated at the rate of 1 mm/d. Preoperative clinical photographs, dental casts, lateral cephalograms, and panoramic radiographs were taken. Further lateral cephalograms were obtained after the latency period, after completion of the active period of distraction, at the completion of the consolidation period, and at 6 and 12 months postoperatively. The aesthetic outcome was excellent and skeletal advancement of 8 and 7 mm was measured without dentoalveolar compensations.

Melanotic Neuroectodermal Tumor of Infancy Involving the Mandible : 7-Year Follow-Up After Hemimandibulectomy and Costochondral Graft Reconstruction

Oral and maxillofacial tumors occur rarely in the pediatric population compared with the adult population. We report a case of a 6-months old female infant suffering from a melanotic neuroectodermal tumor of infancy involving the mandible. Tumor resection was performed using a submandibular approach; the mandibular defect was reconstructed primarily with autogenous costochondral grafts. During a 7-year follow-up period, there has been no tumor recurrence. The costochondral graft healed well; tracing of panoramic radiographs at 2, 3, and 6 years documented some vertical overgrowth and growth retardation in the transversal dimension. The authors conclude that the use of costochondral grafts despite its controversial role for mandibular reconstruction can be recommended in particular after continuity resections in newborn infants. However, long-term follow-up is necessary as well as secondary corrective surgery at early skeletal maturity.

Segmental unilateral transpalatal distraction in cleft patients.

Patients with unilateral cleft lip and palate (UCLP) can present with an asymmetric transversal deficiency caused by collapse of the lateral maxillary segment at the cleft side. The surgical technique and orthodontic implications of segmental unilateral transpalatal distraction (TPD) after a posterior maxillary subapical osteotomy using the transpalatal distractor (TPD(R)) are described. The differences between unilateral posterior surgical-assisted rapid palatal expansion (SA-RPE) and segmental unilateral TPD are discussed. The proposed orthodontic-surgical treatment strategy certainly has to be validated by long-term studies in the future.

Maxillary distraction osteogenesis: a two-dimensional mathematical model.

Patients with cleft lip and palate with severe maxillary retrusion usually have a mandible with anterior-superior autorotation and subsequent overclosure and loss of the vertical facial dimension. Maxillary distraction osteogenesis can correct the sagittal maxillomandibular relationship and should simultaneously reestablish vertical dimension through maxillary vertical height increase and clockwise rotation of the mandible to restore facial balance. We present a two-dimensional mathematical model in the sagittal plane, which reestablishes sagittal and vertical skeletal deficiencies and proper occlusal alignment for planning maxillary advancement with distraction osteogenesis in patients with cleft lip and palate. The model is illustrated in a case of a 13-year-old boy with a complete bilateral cleft lip and palate and severe maxillary retrusion. The two-dimensional mathematical model described in this article allows the surgeon and orthodontist to calculate in a simple and accurate way the ideal distraction vector to advance the maxilla to its desired position.

Early one-stage repair of complete unilateral cleft lip and palate.

Background: The purpose of this prospective study was to evaluate craniofacial morphology in children with complete unilateral cleft lip and palate treated at the Brussels cleft center after a 1-stage complete closure at 3 months and compare the results with a series of children operated on at 3 and 6 months of age according to the Malek surgical protocol. Methods: A series of 72 consecutive patients who were operated on for nonsyndromic complete unilateral cleft lip and palate were included in this study at approximately the age of 10 years. Thirty-four were treated according to the Malek surgical treatment protocol: the soft palate was closed at a mean (SD) age of 3.04 (0.20) months, followed by simultaneous repair of the lip and hard palate at 6.15 (0.67) months. Thirty-eight underwent 1-stage all-in-one (AIO) closure of the lip and hard and soft palates at 2.98 (0.16) months. Craniofacial morphology was evaluated by means of a digital cephalometric analysis. Cephalometric data were compared with a noncleft control group (n = 40) matched according to age. The same 2 series of children were followed up until 15 years of age, and the results were again compared. Results: Statistical analysis (analysis of variance with post hoc Tukey test) showed in both groups who were operated on a decreased anteroposterior growth compared with the children without cleft at 10 years but the AIO group only was not different from the group without cleft. The maxillary (MxPI/SN) plane was significantly (P = 0.002) increased in the Malek cleft group compared with the AIO group with cleft. At 15 years of age, a difference was not observed anymore between the 2 groups for the anteroposterior growth or for the maxillary plane inclination. Conclusions: One-stage AIO closure based on the Malek surgical principles provided good anteroposterior midfacial morphology and resulted in less opening of the maxillary plane to the anterior cranial base.

Reliability and validity of a modified lateral cephalometric analysis for evaluation of craniofacial morphology and growth in patients with clefts.

In previous intercenter studies on craniofacial morphology in patients with unilateral cleft lip and palate, probable surgical-induced changes in mandibular morphology and spatial position related to posterior vertical maxillary morphology were identified by our group. These changes could not be detected in other cephalometric cleft studies because posterior vertical maxillary height and vertical mandibular ramus length were not measured simultaneously. This study presents a modified digital lateral cephalometric hard and soft tissue analysis (Onyx Ceph software, version 2.5.6.; Image Instruments GmbH, Chemnitz, Germany) to evaluate craniofacial morphology and growth patterns in patients with clefts. Forty controls without clefts were used to evaluate the accuracy, reliability, and validity of this analysis for future cleft research. Measurement error according to the method of Bland and Altman was less than 1.00° and 1.00 mm, whereas squared correlation coefficients (r2) according to the method of Sackett et al showed a high reliability. Method comparison tests according to the method of Bland and Altman clearly showed that the modified digital cephalometric analysis (“test”) was valid for future cleft research compared with the “gold standard” (conventional cephalometry).

Mandibular morphology in complete unilateral cleft lip and palate

Objective The purpose of this study was to evaluate and compare mandibular morphology and spatial position in children with complete unilateral cleft lip and palate (UCLP) treated at two different cleft centers (Hannover and Brussels) following different surgical treatment protocols. Patients A total of 62 Caucasian children (40 boys, 22 girls) with nonsyndromic complete unilateral cleft lip and palate (UCLP) were evaluated by means of conventional cephalometric analysis at approximately the age of 10 years. Data of both cleft groups were compared with a control, noncleft group (n = 40) matched according to age and sex. Interventions The Hannover children with cleft (n = 36) underwent lip repair at a mean age of 5.83 ± 1.16 months. The hard and soft palates were closed at a mean age of 29.08 ± 4.68 and 32.25 ± 4.29 months, respectively. The Brussels children with cleft (n = 26) were treated according to the Malek surgical protocol with soft palate repair at a mean age of 3.04 ± 0.20 months and simultaneous lip and hard palate repair at a mean age of 6.15 ± 0.68 months. Results Statistical analysis (analysis of variance with post hoc Tukeys test) showed a significant (p = .001) smaller mandibular ramus length (Co-Go) in the Brussels cleft group, compared with the control group. The Hannover-Brussels comparison data revealed that the S-N-B angle was significantly (p = .047) less in the Brussels cleft group. Conclusions The influence of surgical procedures in patients with UCLP might not be restricted to the maxilla but could influence mandibular spatial position to the cranial base. Because of these positional changes of the mandible, both cleft groups showed facial balance.