Experimental Study on Anatomic Reduction of Lateral Pterygoid Muscle(Simulated Manipulation Fracture Reduction)and Condylar Free Reduction for Condylar Fracture

[Objectives]To compare the fracture healing of keeping lateral pterygoid muscle anatomic reduction(simulated manipulation fracture reduction)with condylar free reduction in the treatment of condylar fractures.[Methods]Twenty-four New Zealand rabbits were randomly divided into two groups to mandibular condylar neck fracture model was established.one team keep the lateral pterygoid muscle,the other excise it.Cervical vascular perfusion was done with ink before animals executed after operation 2,4,6 and 8 weeks.Bilateral anteroposterior and mediolateral condylar diameters measured.Changes of operation side condylar proliferating layer,microvessel number and bone parameters were observed and analyzed after slices and HE staining.[Results]The mediolateral condylar diameters of operation side were significantly smaller than health side in condylar free reduction group at the 4,6,8 weeks(P<0.05),but there was no statistical difference in the anteroposterior condylar diameters at each time point(P>0.05).There were no significant differences in the anteroposterior and mediolateral condylar diameters of the anatomic reduction lateral pterygoid muscle group compared between the operation side and health side(P>0.05).The number of microvessel in condylar free reduction group were smaller than those in anatomic reduction lateral pterygoid muscle group(P<0.05).There were significant differences in BV/TV,Tb.Th,Tb.Sp between the condylar free reduction group and the anatomic reduction lateral pterygoid muscle group(all P<0.05),and the Tb.N were significantly differences between two groups at the 4,6,8 weeks(P<0.05).[Conclusions]When the condyle is fractured it should keep lateral pterygoid muscle(manipulation fracture reduction)as possible,which is important in the fracture healing and functional recovering of mandibular.

Virtual surgical planning is a useful tool in the surgical management of mandibular condylar fractures

Purpose:The aim of this study is to evaluate the application value of virtual surgical planning in the management of mandibular condylar fractures and to provide a reliable reference.Methods:This was a prospective randomized controlled study and recruited 50 patients requiring surgical treatment for their mandibular condylar fractures.The inclusion criteria were patients(1)diagnosed with a condylar fracture by two clinically experienced doctors and required surgical treatment;(2)have given consent for the surgical treatment;and(3)had no contraindications to the surgery.Patients were excluded from this study if:(1)they were diagnosed with a non-dislocated or only slightly dislocated condylar fracture;(2)the comminuted condylar fracture was too severe to be treated with internal reduction and fixation;or(3)patients could not complete follow-up for 3 months.There were 33 male and 17 female patients with 33 unilateral condylar fractures and 17 bilateral condylar fractures included.The 50 patients were randomly(random number)divided into control group(25 patients with 35 sides of condylar fractures)and experimental group(25 patients with 32 sides of condylar fractures).Virtual surgical planning was used in the experimental group,but only clinical experience was used in the control group.The patients were followed up for 1,3,6 and 12 months after operation.Variables including the rate of perfect reduction by radiological analysis,the average distance of deviation between preoperative and postoperative CT measurements using Geomagic software and postoperative clinical examinations(e.g.,mouth opening,occlusion)were investigated for outcome measurement.SPSS 19 was adopted for data analysis.Results:The average operation time was 180.60 min in the experimental group and 223.2 min in the control group.One week postoperatively,CT images showed that the anatomic reduction rate was 90.63%(29/32)in the experimental group and 68.57%(24/35)in the control group,revealing significant difference(X^(2)=4.919,p=0.027).Geomagic comparative analysis revealed that the average distance of deviation was also much smaller in the experimental group than that in the control group(0.639 mm vs.0.995 mm;t=3.824,p<0.001).Conclusion:These findings suggest that virtual surgical planning can assist surgeons in surgical procedures,reduce operative time,and improve the anatomic reduction rate&accuracy,and thus of value in the diagnosis and treatment of condylar fractures.