J Huazhong Univ Sci Technol [Med Sci] 35(2):265-270,2015 DOI 10.1007/s11596-015-1422-5 J Huazhong Univ Sci Technol［Med Sci］ 35(2):2015 265
Condylar and Occlusal Changes after High Condylectomy and Orthodontic Treatment for Condylar Hyperplasia Loaye A.El.mozen, Qing-gong MENG (孟庆功), Ying-jie LI (李颖杰), Xing LONG (龙 星)#, Guo-xin CHEN (陈国新)# Department of Oral and Maxillofacial Surgery, the State Key Laboratory of Breeding Base of Basic Science of Stomatology & Key Laboratory of Oral Biomedicine of Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan 430079, China © Huazhong University of Science and Technology and Springer-Verlag Berlin Heidelberg 2015
Summary: Condylar hyperplasia (CH) of human temporomandibular joint (TMJ) often occurs unilaterally, and causes occlusal disturbance and facial asymmetry. The purpose of this study was to compare the effects of high condylectomy with and without postsurgical orthodontic treatment. Forty patients were diagnosed as having active CH and treated with high condylectomy. Patients in group A (n=24) took the postsurgical orthodontic therapy immediately after surgery, and those in group B (n=16) did not take orthodontic therapy. For both groups, the mandibular ramus height on the affected side was decreased significantly after surgery. Orthodontic treatment promoted maxillary alveolar remodeling significantly by depressing alveolar bone of the affected side and increasing alveolar bone of the nonaffected side. Better improvement for facial midline deviations was observed in group A than in group B. In both groups, the condylar remodeling was observed and manifested by the smoothening of condylar surface and returning of condyle to normal position in glenoid fossa. It was concluded that high condylectomy in the treatment of active CH of TMJ improved the functional occlusion and facial aesthetic. Postsurgical orthodontic therapy could more effectively enhance maxillary alveolar and condylar remodeling, and more rapidly and meticulously establish the stable occlusal and normal position of condyle than the spontaneous remodeling. Key words: dentofacial asymmetry; condylar hyperplasia; condylectomy; orthodontic treatment
Condylar hyperplasia (CH) of human temporomandibular joint (TMJ) is the unilateral excessive growth of the mandibular condyle, causing facial asymmetry and occlusal disturbance. For unknown reason, one of the condylar growth areas becomes more active than others, which may be associated with joint pains and dysfunctions[1–3]. On clinical observation, hemimandibular elongation from CH presents the features of unilateral occurrence, severe deviation of chin, lower midline to the contralateral side, and the lower incisors tilted to the affected side. CH also causes the dentoalveolar compensations and related soft tissue changes in the maxilla[4–6]. Furthermore, these effects of unilateral condylar elongation are quite suitable for high condylectomy to correct this kind of mandibular asymmetry and to arrest this condylar overgrowth. After high condylectomy, open-bite usually occurs in the non-affected side and premature contact occurs in the affected side[7, 8]. However, some patients are reluctant to take the postsurgical orthodontic treatment. The consequence without the postsurgical orthodontic treatment had not yet been investigated. The purpose of this study was to compare the condylar and occlusal changes of high condylectomy with and without postsurgical orthodontic treatment.
Loaye A.El.mozen, E-mail: [email protected]
# Corresponding authors, Xing LONG, E-mail: [email protected]
; Guo-xin CHEN, E-mail: [email protected]
1 PATIENTS AND METHODS This retrospective study involved 40 patients (23 females and 17 males) who were diagnosed with active CH from 2005 to 2012, and treated in the Department of Oral and Maxillofacial Surgery, School & Hospital of Stomatology, Wuhan University. This study was consented and approved by the Ethics Committee of the School & Hospital of Stomatology, Wuhan University. Before the surgery, all patients underwent the standardized radiographic examinations, including panoramic tomography, cephalometry, and cone-beam computed tomography (CBCT). The bone scanning by single photon emission computed tomography (SPECT) was used to assess the active growth of condyle (fig. 1). Serial extra- and intra-oral photographs were taken before and after treatment. Clinical examinations were performed on all patients for facial symmetry, TMJ function and occlusion conditions. All the patients underwent the standardized clinical and radiographic examinations at the following intervals: pre-surgery (P1), post-surgery (P2), and follow-up (P3). Then, all patients underwent high condylectomy to arrest the overgrowth of the condyle and to prevent future facial asymmetry after the same standardized clinical and radiographic investigation when the condylar growth was in the active phase. Under general anesthesia with nasal cannula, this surgery was performed through the preauricular incision to reach TMJ region. Condylec-
266 J Huazhong Univ Sci Technol［Med Sci］ 35(2):2015 tomy was achieved by removal of the excessive top of the hyperactive condyle according to the measurement of ramus height. Then the articular disc was repositioned backward upon the shaved condylar head. Two titanium implants were planted in the affected side, between the upper first premolar and canine tooth, and between lower lateral incisor and canine tooth, respectively. Intermaxillary traction was applied immediately after the surgery for reposition of the shaved condylar head in glenoid fossa. One month after the surgery, the two implants were taken out from patients. Based on the previous shape of condyle, the remodeling changes after high condylectomy were assessed during the follow-up period. The remodeling changes of condyle include the profile of condyle and new bone formation, and condylar position in glenoid fossa was evaluated through CBCT.
19.83±3.26 years, 8 patients were affected in the left side, and 16 patients affected in the right side. The average post-orthodontic follow-up period was 13.8 months. In group B (n=16), there were 10 females and 6 males with the mean age of 19.93±4.13 years, 4 patients were affected in the left side, and 12 patients affected in the right side. The average post-surgical follow-up period was 18.4 months. The treating procedures for representative patients in group A and group B are presented in fig. 4 and fig. 5, respectively.
Fig. 2 The measurements on panoramic X-ray photograph Ramus height (RH): distance between the most cranial point of the high condyle (HC) and the most inferior point of the gonial angle (AG); maxilla height (MH): distance between the most inferior point of the orbit (OR) and the tip of the mesiobuccal cusp of the maxillary first molar (U6)
Fig. 1 Bone scanning showing the increased activity (indicated by the arrow) of the left condyle of a typical patient
Then these patients were divided into two groups based upon their desire to take postsurgical orthodontic treatment. In group A, there were 24 patients who took the orthodontic treatment one month after surgery in order to further correct the transverse and vertical dental discrepancy and enhance the functional occlusion and facial aesthetic. In group B, there were 16 patients who did not receive the postsurgical orthodontic treatment. The multi-loop edgewise arch wire (MEAW) with the intermaxillary elastic traction was used in the postsurgical orthodontic treatment. Improvements of facial aesthetic in the treatment outcome were evaluated by panoramic tomography and CBCT. Ramus height (RH) and maxilla height (MH) were investigated (fig. 2). The mandibular ramus length and the maxillary height on both sides were measured. Meanwhile, the change of facial midline was measured before and after surgery, postorthodontic treatment, and in follow-up stage in both groups (fig. 3). The results were analyzed by Digimizer software 184.108.40.206. 2 RESULTS 2.1 Clinical Data Forty patients were involved in this study, with age ranging from 14 to 33 years old. In group A (n=24), there were 13 females and 11 males with the mean age of
Fig. 3 A: Pre-surgery CBCT showing the deviation of the facial midline; B: Follow-up CBCT showing normalized facial midline
2.2 Radiographic Data In group A, the mandibular RH on affected side showed significant difference between P1 and P2 (P