Custom-Made Titanium Miniplates Associated With Ultrahigh-Molecular-Weight Polyethylene Graft in Orthognathic Surgery: An Adjunct to Maxillary Advancement.

Patients with considerable maxillomandibular anteroposterior discrepancies and maxillary hypoplasia require corrective treatment through orthognathic surgery. However, in the treatment of severe maxillary retrognathism, it is necessary to reconstruct areas of bone deficiency through grafting techniques in addition to maxillary advancement using only the Le Fort I osteotomy. Treatment in these patients is more challenging and requires high surgical predictability. Alloplastic materials often have been used for the reconstruction of poor bone contours. Ultrahigh-molecular-weight polyethylene (UHMWPE) is currently an excellent filler material for poor bone regions and is a good substitute for autografts and other alloplastic materials for its unique properties, including high biocompatibility. Insertion of this material in the fixation system customized for virtually planned orthognathic surgeries is an innovative technique. This report describes the insertion of UHMWPE into custom-made titanium miniplates manufactured by computer-aided design and computer-aided manufacturing technology for orthognathic surgery consisting of maxillary advancement and mandibular retrusion to treat a patient with Crouzon syndrome, Class III malocclusion, and severe maxillary retrognathism.

Morphometric study of mandibular ramus related to sagittal ramus split osteotomy and osteosynthesis.

The objective of this study was to quantify the cortical bone thickness of the mandibular ramus to determine conditions related to sagittal split ramus osteotomy and placement of screws. The patient sample comprised 44 subjects of ages ranging from 46 to 52 years (mean age, 49 years). The cone-beam computed tomography was performed and realized 3 cuts in the third molar area (section A), 5 mm posterior (section B), and 5 mm posterior to the latter (section C). Measurement in the cortical areas of the superior and inferior levels related to mandibular canal and measurement related to the total width of the mandible was executed. Intraclass correlation coefficient with P < 0.05 was used. The result showed that the buccal and lingual cortical zone did not present statistical differences, and the minor value was 1.5 mm for each one. There were no differences in the superior and inferior cortical bone, and the total width of the mandible was between 15.9 and 8.5 mm in the anterior area, between 17.4 and 12.8 mm in the middle area, and between 18 and 8.8 mm in the posterior area. The distance superiorly to the mandibular canal presented a minimal SD with a mean of 8.5 mm in the anterior region, 10.6 mm for the middle region, and 12.5 mm in the posterior region. In conclusion, the cortical thickness of the mandibular ramus in the adult population is particularly strong and offers a good anchorage for screw insertion in sagittal split ramus osteotomy.

Retraction: Bacterial adhesion and colonization differences between zirconia and titanium implant abutments: an in vivo human study.

[This retracts the article on p. 217 in vol. 42, PMID: 23346465.].

Accuracy in the Diagnosis of the Mental Nerve Loop. A Comparative Study Between Panoramic Radiography and Cone Beam Computed Tomography.

Dental implant and chin osteotomy are executed on the mandible body and the mental nerve is an important anatomical limit. The aim of this research was to know the position of the mental nerve loop comparing result in panoramic radiography and cone beam computed tomography. We analyzed 94 hemimandibles and the patient sample comprised female and male subjects of ages ranging from 18 to 52 years (mean age, 35 years) selected randomly from the database of patients at the Division of Oral Radiology at Piracicaba Dental School State University of Campinas; the anterior loop (AL) of the mental nerve was evaluated regarding the presence or absence, which was classified as rectilinear or curvilinear and measurement of its length was obtained. The observations were made in the digital panoramic radiography (PR) and the cone beam computed tomography (CBCT) according to a routine technique. The frequencies of the AL identified through PR and CBCT were different: in PR the loop was identified in 42.6% of cases, and only 12.8% were bilateral. In contrast, the AL was detected in 29.8% of the samples using CBCT, with 6.4% being bilateral; Statistical comparison between PR and CBCT showed that the PR led to false-positive diagnosis of the AL in this sample. According to the results of this study, the frequency of AL is low. Thus, it can be assumed that it is not a common condition in this population.

Bacterial adhesion and colonization differences between zirconia and titanium implant abutments: an in vivo human study.

PURPOSE: Several parameters have been described for determining the success or failure of dental implants. The surface properties of transgingival implant components have had a great impact on the long-term success of dental implants. The purpose of this study was to compare the tendency of two periodontal pathogens to adhere to and colonize zirconia abutments and titanium alloys both in hard surfaces and soft tissues. METHODS: Twelve patients participated in this study. Three months after implant placement, the abutments were connected. Five weeks following the abutment connections, the abutments were removed, probing depth measurements were recorded, and gingival biopsies were performed. The abutments and gingival biopsies taken from the buccal gingiva were analyzed using real-time polymerase chain reaction to compare the DNA copy numbers of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, and total bacteria. The surface free energy of the abutments was calculated using the sessile water drop method before replacement. Data analyses used the Mann Whitney U-test, and P-values below 0.05 find statistical significance. RESULTS: The present study showed no statistically significant differences between the DNA copy numbers of A. actinomycetemcomitans, P. gingivalis, and total bacteria for both the titanium and zirconia abutments and the biopsies taken from their buccal gingiva. The differences between the free surface energy of the abutments had no influence on the microbiological findings. CONCLUSIONS: Zirconia surfaces have comparable properties to titanium alloy surfaces and may be suitable and safe materials for the long-term success of dental implants.

Condylar Resorption After Orthognathic Surgery: A Systematic Review.

The aim of this research was to evaluate the risk factors related to condylar resorption (CR) after orthognathic surgery. Was realized a systematic review with a search of the literature performed in the electronic databases PubMed, MedLine, Ovid, Cochrane Library for current evidence in the world literature as conducted, and relevant articles were selected in according to inclusion and exclusion criteria and the findings were compared. Eight papers, (follow-up 12 months to 69 months) were including. A sample of 2567 patient with mandible or bi maxillary surgery with an age range from 14 to 46 year old was observed. In 137 patients (5.3%) CR was observed, with a 97.6% (122) female. CR was related to 118 cases with mandibular deficiencies with high mandibular plane (advancement surgery). CR were present principally in bi maxillary surgery with a 103 cases (75.2%) and only two papers show any analysis to the relation with TMJ dysfunction. Current evidence in CR is poor but supports those female patients with mandibular deficiency and high mandibular plane angle submitted to bi maxillary surgery with change in occlusal plane (counterclockwise) are associated with condylar resorption after orthognathic surgery.