Recommendations to minimize tooth root remodeling in patients undergoing maxillary osteotomies.

The purpose of this study was to report root remodeling/resorption percentages of maxillary teeth following the different maxillary osteotomies; i.e. one-piece, two-pieces, three-pieces Le Fort I, surgically assisted rapid palatal expansion (SARPE). The possibility of relationships between root remodeling and various patient- and/or treatment-related factors were further investigated. A total of 110 patients (1075 teeth) who underwent combined orthodontic and orthognathic surgery were studied retrospectively. The sample size was divided into: 30 patients in one-piece Le Fort I group, 30 patients in multi-pieces Le Fort I group, 20 patients in SARPE group and 30 patients in orthodontic group. Preoperative and 1 year postoperative cone beam computed tomography (CBCT) scans were obtained. A validated and automated method for evaluating root remodeling and resorption in three dimensions (3D) was applied. SARPE group showed the highest percentage of root remodeling. Spearman correlation coefficient revealed a positive relationship between maxillary advancement and root remodeling, with more advancement contributing to more root remodeling. On the other hand, the orthodontic group showed a negative correlation with age indicating increased root remodeling in younger patients. Based on the reported results of linear, volumetric and morphological changes of the root after 1 year, clinical recommendations were provided in the form of decision tree flowchart and tables. These recommendations can serve as a valuable resource for surgeons in estimating and managing root remodeling and resorption associated with different maxillary surgical techniques.

Modified Intraoral C-Osteotomy.

ABSTRACT: Repeated sagittal split osteotomy might impose an increased risk for damage of the inferior alveolar nerve. Another contemporary orthognathic issue is surgical management of malocclusion following condylar resorption. Here we describe a modified C-osteotomy technique as a proposed solution for these difficulties in orthognathic surgery. The modified C-osteotomy might induce less stress on the condyles reducing the risk for relapse subsequent to condylar resorption, as well as reduce the risk of inferior alveolar nerve damage.

Three dimensional assessment of segmented Le Fort I osteotomy planning and follow-up: A validation study.

OBJECTIVES: The planning accuracy and stability during follow-up of segmented Le Fort I osteotomy, often evaluated using 2D cephalometry and dental cast analysis, is controversial. The aim of this study is to develop and validate a 3D semi-automatic, voxel-based registration assessment protocol to evaluate planning accuracy and stability of segmented Le Fort I osteotomy with individualization of the maxillary segments. METHODS: Preoperative, immediate postoperative and six months postoperative CBCT images were used to evaluate accuracy and stability of the individual segments in 20 patients (13 female; 7 male) who underwent segmented Le Fort I osteotomy. Three translational (left/right, intrusion/extrusion, anterior/posterior) and three rotational (pitch, roll, yaw) dimensions were calculated for each maxillary segment by means of a user-friendly module. Inter- and intra-observer Inter Class Coefficient (ICC) and mean absolute difference (MAD) were calculated. RESULTS: The inter- and intra-observer reliability ICC varied between 0.93 and 0.99 for the translational and rotational accuracy and stability assessments, indicating excellent reliability. The MAD ranged between 0.21 mm and 0.32 mm for the translational error and between 0.6° and 0.9° for the rotational dimension. CONCLUSIONS: The 3D assessment protocol for accuracy of segmented Le Fort I planning and short-term follow-up, proved to have high reliability with only a small margin of error. CLINICAL SIGNIFICANCE: The proposed 3D assessment protocol allows future in-depth analysis of segmented Le Fort I osteotomy and might implicate future improvement where necessary.

Visual and haptic perceptibility of 3D printed skeletal models in orthognathic surgery.

OBJECTIVE: To assess the anatomical and tactile quality of 3D printed models derived from medical printers for application in orthognathic surgery. METHODS: A CBCT-scan of an 18 years old female patient was acquired with NewTom VGi evo (NewTom, Verona, Italy). Thereafter, mandibular bone was segmented and isolated from the scan using Mimics inPrint 2.0 software (Materialise NV, Leuven, Belgium). Six printers with different technologies were utilized for printing skeletal models, which included stereolithography (ProX800, 3D Systems, Rock Hill, SC, USA), digital light processing (Perfactory 4 mini XL, Envisiontec, Dearborn, MI, USA), fused deposition modeling (uPrint SE, Stratasys, Eden Prairie, MI, US), colorjet (ProJet CJP 660Pro, 3D Systems, Rock Hill, SC, USA), multijet (Objet Connex 350, Stratasys, Eden Prairie, MN, USA) and selective laser sintering (EOSINT P700, EOS GmbH, Munich, Germany). A questionnaire was designed, where 22 maxillofacial residents scored whether the printed models were able to mimic bone color, texture and anatomy. Five maxillofacial surgeons performed bone cutting with screw insertion/removal to assess the tactile perceptibility. RESULTS: In relation to texture and cortical and medullary anatomy replication, Perfactory 4 mini XL printer showed the highest mean score, whereas, Objet Connex 350 scored highest for color replication. The haptic feedback for cutting and screw insertion/removal varied for each printer, however, overall it was found to be highest for ProX800, whereas, EOSINT P700 was found to be least favorable. CONCLUSIONS: The digital light processing based Perfactory 4 mini XL printer offered the most acceptable anatomical model, whereas, deficiencies existed for the replication of haptic feedback to that of real bone with each printer. CLINICAL SIGNIFICANCE: The study outcomes provide pearls and pitfalls of 3D printed models utilizing various printers and technologies. There is a need for research on multi-material printing as such to improve the haptic feedback of skeletal models and render the models more human bone-like to improve surgical planning and clinical training.

Complications Following One-Stage Versus Two-Stage Surgical Treatment of Transverse Maxillary Hypoplasia.

PURPOSE: Contemporary literature suggests a similar transverse stability of a surgical-assisted rapid palatal expansion and a segmented Le Fort I osteotomy. The aim of this study was to compare postoperative complications of 1-stage (segmental maxillary osteotomy) and 2-stage (surgical-assisted rapid palatal expansion followed by Le Fort I osteotomy) treated patients to determine the preferred treatment strategy. MATERIALS AND METHODS: This retrospective study included 74 consecutive patients (age range: 14 - 57 years; 36 males, 38 females) with a moderate transverse maxillary hypoplasia: 32 patients were treated in a 1-stage protocol and 42 in a 2-stage protocol with a postoperative follow-up of at least 1 year. Dental complications such as loss of teeth, gingival dehiscence, periodontal bone loss, apical root resorption, and surgical complications such as pain, hemorrhage, altered neurosensitivity, wound infection, aseptic necrosis were analyzed. Univariate analysis consisted of a generalized linear model with logit link or Fisher exact test. RESULTS: No significant difference was found for group characteristics except for longer orthodontic treatment time in the 2-stage group. Incidence and severity of complications were comparable for the 1-stage and 2-stage patients. Only overall pain was significantly greater in the 2-stage patient group (P = .038). CONCLUSIONS: Considering a similar complication rate and transversal stability, the choice between 1-stage and 2-stage approach for patients with a moderate transverse maxillary hypoplasia should be patient specific.

A retrospective analysis of the complication rate after SARPE in 111 cases, and its relationship to patient age at surgery.

PURPOSE: Surgically assisted rapid palatal expansion (SARPE) is a well-known surgical intervention for treating maxillary transverse deficiencies (MTDs). This investigation aimed to evaluate the complication rate after SARPE, and its relationship to patient age. MATERIALS AND METHODS: Based on multivariate analyses, the complication rate after SARPE and its association with increasing age in 111 patients with MTD was evaluated. In every case the following variables were evaluated: age, gender, concomitant surgery, expander appliance, perioperative and dental complications, pain score, neurosensory disturbances (NSDs), postoperative excessive haemorrhage, length of hospital stay, infection, oronasal communication, palatal ulceration, asymmetrical maxillary expansion, mal- or non-union of the bone, lacrimation, and mechanical failure. RESULTS: Overall, 58 (52.25%) patients had minor-to-severe complications. The most common complications were NSDs (27.03%) and postoperative pain (13.51%). Multivariate analysis showed that the frequency of dental complications (mean age 35.9; SD = 10.5140; p = 0.0021∗), NSDs in general (mean age 30; SD = 9.9827; p = 0.0157∗), NSDs lasting more than 4 weeks (mean age 30,9583; SD = 10.6260; p = 0.0105∗), and NSDs lasting more than 1 year (mean age 36.2; SD = 8.7579; p = 0.0201∗) increased significantly with patient age. CONCLUSION: Detailed data analysis revealed a limited number of severe, long-term complications after SARPE. However, careful patient selection is recommended in elderly cases.

Frequency and Management of Craniofacial Syndromes.

BACKGROUND: Craniofacial syndromes occur in approximately 1 in 5600 to 100,000 infants, often resulting in significant morbidity. Due to the heterogeneity of this patient population, no clear consensus consists on optimal treatment modalities and timing. The aim of this study was to analyze the craniofacial syndrome population that were treated at the University Hospital Leuven. METHODS: A retrospective analysis of patients with a clinical diagnosis of a craniofacial syndrome was performed. Inclusion criteria were patients with a clinical diagnosis of a craniofacial syndrome and that received treatment between "2000-2005" and "2010-2015." Patients with nonsyndromic conditions were excluded. Data regarding patient characteristics, treatment modalities, and treatment outcomes were analyzed. RESULTS: After matching the inclusion criteria, 98 eligible patients, affected by 40 different syndromes were included. In the period of "2000 to 2005," 48 patients were treated, as compared to 50 patients in the period of "2010 to 2015." A statistically significant decrease over time is seen for cleft surgery and orthodontic treatment (P = 0.0017 and P = 0.0015, respectively). No statistically significant differences were found concerning the age at which treatment was received (P = 0.42). Significant associations between treatment modalities were found for orthognathic surgery and distraction osteogenesis (P < 0.0001), orthognathic surgery and orthodontic treatment (P < 0.0001), and between orthodontic treatment and distraction osteogenesis (P = 0.03311). CONCLUSION: A decline in cleft reconstruction surgery and orthodontic treatment for patients with craniofacial syndromes was seen over time. A significant association was found between distraction osteogenesis and orthognathic surgery, possibly due to higher reintervention rates for patients treated at a young age.