| Objective: Condylar has a close relationship with temporomandibular joint, occlusion, mandibular, and facial morphology, therefore, condylar bone change is a focus of research and attention to oral physician in all the subjects. The aim of this study was to analyse distribution characters of sex and age of patients with condylar bone changes, and study the radiological characteristics of cranial and maxillofacial in the idiopathic condylar resorption(ICR) with cone beam computed tomography(CBCT) data.Method: A total of patients with condylar bone changes during november 2012 to november 2014 was selected from the computer data base. All patients had been used with CBCT. Then their left and right side of the condylar bone CBCT data were analysis respectively. According to condylar bone change, patients can be divided into five groups: flattening(F), erosion(E), sclerosis(S), osteophytes(O) and resorption(R). The data were analyzed by SPSS 17.0 to characterize sex and age. Then according to clinical and CBCT data records, selected 41 ICR patients from resorption(R) group, and divided them into unilateral group and bilateral group. 41 healthy volunteers were selected as control group. Use Invivo5 software to read CBCT data of all subjects and measure each related indicators of cranial and maxillofacial, then SPSS 17.0 statistically analyzed.Results:Test one1. Totally 266 subjectswere included into the trial; Male to female ratio was 1:2.4, The female cases were much more than males, There were 62.8% of patients in the age group of 10 to 39 years; Females showed a significant peak of prevalence of condylar bone change in the age group of 20 to 29 years.2. The average age of the bone sclerosis patients is significantly higher than the average age of patients without bone sclerosis(P < 0.05); The average age of the condylar resorption patients is significantly lower than the average age of patients without condylar resorption(P < 0.05).Test two1. There is no significant statistical difference between left and right sides in bilateral ICR group and normal group(P>0.05).2. Significant statistical differences were also observed in ICR group, SNB, NP-FH, FH-SGn?L1-MP?S-Go, Co-Go, S-Go/N-Me, H, ACo-PCo, PCo-Co and angle of anterior slope are less than that of the normal group( P<0.05); ANB?SN-MP?S-Ar-Go and Co-Go-Me are more than the normal group( P<0.05); SNA?U1-L1?U1-NA?L1-NB?N-Me, Go-Me, S-PCo, ACo-Co and angle of posterior slope had no statistical significance( P>0.05).3. Significant statistical differences were observed in unilateral ICR group, S-Go, Co-Go, S-Go/N-Me, H, ACo-PCo, PCo-Co and angle of anterior slope are less than that of the contralateral( P<0.05); S-Ar-Go and Co-Go-Me are more than the contralateral( P<0.05); SNB?ANB?SN-MP?NP-FH?FH-SGn?SNA?U1-LI?U1-NA?L1-NB?L1-MP?N-Me?Go-Me?S-PCo?ACo-Co and angle of posterior slope had no statistical significance( P>0.05).Conclusion:1. Condylar bone changes develops in 10-39, and were more prevalent in females than males, females showed peak of prevalence of condylar bone changes in the age group of 20 to 29 years.2. In the condylar bone change type,bone sclerosis of the onset age is late; The onset age of bone resorption is early.3. ICR is a kind of bone resorption disease specially occurred in condylar, and other parts of the mandible are not affected, the resorption is mainly occurred in the top and anterior slope of the condylar, and the reduction of condylar height is the main performance.4. Mandibular retraction may occurs when the condylar absorption involving bilateral mandibular, this is due to mandibular rotation, rather than retrodisplacement; But if the condylar absorption involving only one side, the affected side present backword mandibular rotation, while the normal side present forward mandibular rotation, this process ultimately results in an asymmetry that jaw deflection and deviated to the affected side. |
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