Patent RU-2761755-C1 (RU)
Title: Method for transantral reconstruction of the lower orbital wall in children
Inventor: Timofeeva Anna Vyacheslavovna
IPC: A61B17/00
Filed: 2020-11-27
Granted: 2021-12-13
Abstract: FIELD: medicine. 
     SUBSTANCE: invention relates to medicine, namely, to maxillofacial surgery. Intraoral access is executed along the transitional maxillary fold from the side of damage to the lower orbital wall. At a step of 5 mm from the gingival margin, for the length of 2 to 6 teeth, a club-shaped incision is made by monopolar coagulation through all layers to the bone. Using a raspatory, the anterior wall of the maxillary sinus is then skeletonised, wherein the skeletonising borders are: the medial-piriform aperture, the lateral-zygomatico-alveolar buttress, and the infraorbital foramen on top. Access to the maxillary sinus is then executed, forming an artificial anastomosis - antrostoma, starting with applying a 3-mm burr hole with a drill 3 mm laterally and 3 mm below the infraorbital foramen until the sensation of a fall into the cavity of the maxillary sinus. Then, using a cutter, a fragment of the anterior wall of the maxillary sinus is cut out starting from the applied burr hole, leaving a rim with a width of 3 mm below the infraorbital nerve, monitoring the location of the dental roots from below. The sinus is then sanitised. The mucosa is then removed from the upper and lower walls of the maxillary sinus under control of endoscopes with a diameter of 2.4 or 4 mm with a viewing angle of 0°, 30°. The endoscope is therein secured in a mechanical hand or held by an assistant. Then, using a microsurgical raspatory, palpating, the borders of the fracture of the lower orbital wall are determined, the volume and composition of the hernial bulging of paraorbital tissues are estimated. The edge of the medial fragment of the fracture is found by palpation, the fragment is moved downward increasing the diastasis between the fragments. Using a second raspatory, the paraorbital tissues are set through the fracture line into the orbital cavity. The medial bone fragment is then released while pressed upward, restoring the contour of the lower orbital wall. The effectiveness of setting of the injured tissues is estimated using the Converse traction test. In the event of repeated falling of the paraorbital tissues into the fracture line due to the large diastasis between the fragments, reconstruction of the lower orbital wall is executed. For this purpose, an S-shaped graft is used, made of titanium dynamic mesh manufactured by Depuy Synthes. The graft is secured at two points: on the anterior wall of the maxillary sinus on the medial or lateral side from the infraorbital foramen and inside the sinus toward the posteroinferior wall. Securing is executed with self-drilling screws with a diameter of 1.5 mm and a length of 3 mm. The position of the eyeball and mobility thereof are estimated, excluding entrapment of paraorbital tissues by the graft. The maxillary sinus is washed with a 1% dioxidine solution. The periosteal-muscular layer is then sutured in layers with loop sutures using a Vicryl plus 4-0 thread and the mucosa with a blanket suture using a Vicryl plus 4-0 thread. 
     EFFECT: method provides a possibility of eliminating bone defects of the lower orbital wall, eliminating enophthalmos, hypophthalmos and limitation of eyeball mobility, achieving favourable aesthetic and functional results of the treatment. 
     2 cl, 25 dwg, 1 ex