Maxillary distraction osteogenesis using Le Fort I osteotomy without intraoperative down-fracture

The aim of this study is to present a technique for maxillary distraction osteogenesis using Le Fort I osteotomy without down-fracture. Six cleft-related patients suffering from severe midfacial deficiency were treated with maxillary distraction osteogenesis. The RED II system was chosen as the extraoral device and the Leipzig retention plate system to anchor the maxillary segment. Maxillary distraction osteogenesis was successful in all cases. Cephalometric and clinical evaluation after an average follow-up period of 1 year showed stable results with respect to skeletal and dental relationships. The SNA angle increased from 72.3 degrees to 81.4 degrees and the ANB angle increased by 11.0 degrees immediately after removing the distraction device. After 1 year, the sagittal bone gain remained and the SNA angle had decreased by 0.8 degrees . This technique seems to minimize the risk of the surgical procedure and shorten the operation time. It may become an alternative method for the treatment of patients with severe midfacial hypoplasia.     

Maxillary Sinus Lateral Wall Thickness and Morphologic Patterns in the Atrophic Posterior Maxilla

Background: The aim of the present study is to examine the sinus lateral wall thickness (LWT) of atrophic posterior maxilla (<10 mm) of patients with complete and partial edentulism and determine the influence of residual ridge height (RH), sex, and age on maxillary LWT. Methods: Four hundred fourteen measures were taken from 140 consecutive patients that met the inclusion criteria. On the selected sagittal section, a built‐in digital caliper recorded in millimeters the RH and LWT (a perpendicular line at 3, 5, 7, 10, 13, and 15 mm from the lowest point of the sinus floor). Edentulous spans were further classified as complete edentulous atrophic maxilla (CEM) and partial edentulous atrophic maxilla (PEM). The mixed linear model was used to test the effects of sex, type of edentulism, edentulous span, and RH on the measurement of the LWT of the sinus. Results: Mean LWT for PEM was 1.71 ± 0.12 mm, and for CEM, 1.57 ± 0.07 mm (P = 0.01). The mixed model yielded significant effect of edentulous span (P = 0.048) and interactions among type of edentulism and edentulous span (P <0.001) and edentulous span by RH (P <0.01). Age and RH were positively associated with LWT; however, they did not interact with RH, sex, or type of edentulism. RH has been shown to correlate with edentulous span (P <0.001) and type of edentulism (P = 0.01). The longer the edentulous span, the thinner the LWT. Similarly, RH was larger for PEM (6.85 ± 0.34 mm) than CEM (5.69 ± 0.26 mm). Conclusions: The maxillary sinus lateral wall tends to increase in thickness from the second premolar to the second molar and from 5 mm up to 15 mm. In addition, RH, presence of teeth adjacent to the edentulous atrophic ridge, and age were shown to influence maxillary sinus LWT.     

Bone-plates for stabilizing Le Fort I osteotomies

16 adults were treated by inferior repositioning of the maxilla. Miniaturized plates were used for stabilizing the jaw in its new position. No interpositional bone grafts were used but the osteotomy spaces were covered by strips of cancellous iliac bone. Healing was uncomplicated. Retrospective cephalometric study of the results of treatment showed a mean frontal vertical relapse of about 20% (range 0-100%). The relapse occurred during the early postoperative period. No linear correlation was found between the amount of vertical repositioning and the anterior vertical relapse. We consider that the mini-plate technique is more advantageous than previous methods.     

Surgical Guides for Modified Oblique Le Fort III Osteotomy

Introduction

The present work consists of the specific design of a surgical guide for modified oblique Le fort III osteotomy (MOLFIIIO), developed previously in the Stereolithography model of the patient. The guides are designed to perform an osteotomy for the orbital floor, zygoma and pterygomaxillary fossa. The fundamental objective of the malar guides will be: symmetrical orbitozygomatic osteotomies bilaterally. Regarding the guide of the orbital floor, it is of primary importance to begin the osteotomy 5 mm ahead of the inferior orbital fissure (IOF) in orbital antero posterior direction, crossing the orbital floor. The pterygomaxillary fossa guide, will cover the internal face of the malar bone exactly in the posterior portion of the butres (hidden portion) toward the IOF. This guide will be useful, revolutionize and make it easier and secure to access the osteotomy of the area for a lot of surgeons who fear manipulating the pterigomaxillary fossa in its upper third, due to the fear of damaging the internal maxillary artery, that will be reduced to a minimum with the guides.

Materials and Methods

Initially requires a CT scan, for designed the model patient stereolithography. The guides are prepared from self-curing acrylic and monomer.

Conclusion

Surgical guides are very useful for MOLFIIIO, as being custom, manage to make a stable symmetrical bilateral cut, decreasing the possibility of injury to vascular structures and shorten the surgical time.     

Technique for rigid fixation of Le Fort and palatal fractures

In the surgical repair of Le Fort fractures, fixation is accomplished with either stainless steel wires or bone plates. In 10 patients treated during the last three years at Truman Medical Center, we found that the posterior lateral wall of the sinus, or buttress, had been severely comminuted, making such fixation difficult. With midpalatal fractures, which often accompany Le Fort fractures, palatal collapse and buccal torque of the segments are additional problems. Head frames can be used to maintain vertical dimension in the former cases, but a much simpler technique is available. A similar technique can also be used for midpalatal fractures.