A follow-up study of condyle fracture in children

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1 Int. J. Oral Maxillofac. Surg. 2005; 34: doi: /j.ijom , available online at Clinical Paper Trauma A follow-up study of condyle fracture in children J. Choi, N. Oh, I.-K. Kim Department of Dentistry, College of Medicine, Inha University, Korea J. Choi, N. Oh, I.-K. Kim: A follow-up study of condyle fracture in children. Int. J. Oral Maxillofac. Surg. 2005; 34: # 2005 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved. Abstract. This paper reports a long-term clinical and radiological evaluation of conservatively treated condylar fractures in children. The long-term effects of treating condylar fractures in children with non-surgical therapy were examined in order to resolve the controversial question Does complete remodeling occurs at this age or, if not, is it more likely to be associated with certain types of fractures or other factors? This study was based on a series of 11 consecutive children and adolescents, aged between 3 and 15 years, with fractures of the condylar process who had been treated with conservative therapy. All patients underwent a clinical investigation with a special emphasis on the temporomandibular joint function and facial asymmetry. The patients also underwent a radiological investigation, focusing on the fracture remodeling and symmetry of the mandible, which consisted of a panoramic radiograph, PA and a lateral cephalogram and 3-D CT. No patient complained of an impaired temporomandibular joint (TMJ) function or pain on the affected side. Two out of eight (25%) unilateral and one bilateral fracture show a slight facial asymmetry. Despite the apparent excellent recovery of function, there were marked remodeling changes evident on the CT scan. Such changes are not usually evident on a panoramic radiograph. The radiological investigation showed an incomplete remodeling (six patients, 54.5%) and an asymmetry of the mandible (three patients, 27.3%) in some patients. Non-surgical treatment of condylar fractures in children results in the satisfactory long-term outcome of the jaw function despite the relative high frequency of radiologically noted aberrations. Accepted for publication 13 April 2005 Available online 25 May 2005 Although the mandibular condyle is one of the most common sites of injury to the facial skeleton, it is also the most overlooked and least diagnosed trauma site in the head and neck region. In particular, mandibular fractures in children differ greatly from mandibular fractures in adults because of the incomplete dentition and the growth of the mandible 3. Managing condylar fractures in children continues to be a subject of debate. It has been suggested that these fractures may create serious problems if not properly managed, for example, growth disturbances of the face on the injured side and temporomandibular joint disorders on both the injured and non-injured side. The usually recommended treatment of condylar fractures in children has been non-surgical with a reestablishment of the normal occlusion with or without maxillomandibular fixation (MMF) followed by physiotherapy 12. In conservative treatment, the functional rehabilitation relies on the remodeling capacity of the joint. This is particularly the case in children, because the condyle is a remodeling center / $30.00/0 # 2005 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

2 852 Choi et al. that responds to changes in the relationship of its surrounding structure during development in an adoptive manner, thereby maintaining the normal integrity of the joint during growth 2. Several investigators have reported the treatment results of condylar fractures in children. It appears from these studies that satisfactory treatment results have been observed following condylar fractures in children 1,6,16. However, some patients show altered growth of the mandible. PROFFIT et al. 13 reported that out of 121 patients with severe mandibular asymmetry, 5 10% probably were caused by condylar fractures. The sequelae to condylar fractures includes ankylosis. In an analysis of 44 cases of ankylosis of the temporomandibular joint, TOPAZIAN 19 reported 17 cases correlating with a previous trauma to the joint. The aim of this study was to examine the long-term clinical and radiological results of non-surgically treated condylar fractures in children. Therefore, the longterm effects conservative therapy in treating condylar fractures in children were analyzed in order to resolve the controversial question does complete remodeling occurs at this age or, if not, is it more likely to be associated with certain types of fractures or other factors? The study also evaluated whether or not the treatment results were satisfactory. Materials and methods This study was based on a series of 11 consecutive children and adolescents, aged between 3 and 15 years, with fractures of the condylar process who had previously been treated non-surgically. Table 1 shows the data from the 11 patients with 14 fractured condyles. Patients with isolated condylar fractures as well as patients with additional mandibular fractures were included. Seven of 11 patients had fractures of the other part of mandible. The follow-up period ranged from 1 to 6 years with a mean follow-up of 3.27 years. All condylar fractures were treated nonsurgically. A short period (2 10 days) of intermaxillary fixation was used where there was excessive pain and/or persistent malocclusion. When present, fractures of the mandibular body were treated with an acrylic splint or rigid internal fixation depending on the patient s age and the displacement of the fracture. Fractures were classified as being unilateral or bilateral, and the following three levels of the fracture line location were distinguished: condylar head or intra-capsular fractures, high condylar fractures and low condylar neck fractures. The clinical examination was primarily aimed at detecting possible joint disorders or growth disturbances. Both TMJs were assessed with regard to pain, clicking, locking and crepitus. The maximum mouth opening and deviation from the midline during mouth opening were recorded. Excursions in the horizontal plane were also measured. The facial asymmetry and dental midline deviation were documented in the case of a unilateral fracture. In bilateral cases, the anterior posterior position of the mandible and sagittal and vertical open bite as well as the facial asymmetry was recorded. Panoramic radiographs were taken during the follow-up period 4, 12, 24, and 48 weeks after the trauma. At the follow-up, each patient had a panoramic radiograph, frontal and lateral cephalogram and threedimensional CT taken. On the orthopantomogram, the shape of the condyle was compared with that on the non-fractured side. In the cases of bilateral fracture, it was judged as being normal or having persistent signs of an earlier fracture. A tracing of the condylar head and neck, the ascending ramus and mandibular angle was made. The ramus height was measured as the distance from the gonion to a line drawn tangentially to the top of the condyle (Fig. 1). The differences in the length of the ascending ramus were then measured. On the cephalogram, lateral projections were performed to assess the growth and development of the jaws and the angles SNA, SNB and ANB measured. Frontal projections were also used to assess the facial asymmetry (Fig. 2). A CT examination of the condyle was performed at the Department of Diagnostic radiology, Inha University Hospital (Inchon, Korea) with a high-speed advantage (General Electrics, USA). Patients were placed in the supine position. The head position was stabilized by elastic attachments and the scans was recorded with the teeth in habitual occlusion. Spiral CT scanning was performed with a 170 ma scan electric current and a 3 mm slice thickness. 3-D reconstructions were obtained using Virtual work 4.0 software (3-D analysis software) in various projections. According to the TMJ structure revealed by 3-D CT, the TMJ morphometry (size, condylar angle, position) was determined by the linear and angular measurements (Fig. 3). Results Unilateral condylar fractures Eight patients had unilateral fractures (five boys, three girls: mean age 8.1 years, range 3 15 years), five on the left side and three on the right. Of the five condylar neck fractures, three were classified as being high condylar fractures and two as being low. Three fractures were considered to be intra-capsular fractures (Table 1). Of these patients, five had additional fractures of the mandible; three had Table 1. Patients with respect to age, sex and type of condylar fracture Number Sex Age Fx. side Type of Fx. F/U time IMF (days) 1 M 15 years 2 months Lt Condyle head 4 years 10 months 4 2 M 14 years 8 months Both Rt; condyle head 4 years 6 months 3 Lt; condyle head 3 F 13 years Lt High condyle neck 2 years 7 months 10 4 M 11 years 1 month Lt High condyle neck 1 years 9 months 3 5 F 11 years Both Rt; High condyle neck 4 years 1 month 0 Lt; High condyle neck 6 M 7 years 3 months Lt Low condyle neck 2 years 10 months 0 7 F 6 years 11 months Both Rt; Intra-capsular 3 years 11 months 7 Lt; High condyle neck 8 M 6 years Lt High condyle neck 3 years 1 month 0 9 M 4 years 10 months Lt Intra-capsular 1 years 5 months 0 10 F 3 years 7 months Rt Intra-capsular 1 years 7 months 0 11 F 3 years 3 months Rt Low condyle neck 5 years 10 months 2

3 A follow-up study of condyle fracture in children 853 Fig. 1. Measurement of ramus height. Con: the most superior point of the condyle; Cor: the most superior point of the coronoid process; Inc: the most inferior point of the mandibular notch; C: the intersection of the RL and a perpendicular line from Con; I: the intersection of the RL and a perpendicular line from Inc; G: the intersection of the RL and ML; RL: a tangent line of the mandibular ramus; and ML: a tangent line of the mandibular body. a fracture in the symphysis and two in the parasymphysis region. The mean follow-up period was 2 years and 11 months, range years and the mean age at follow-up was 11 years. There were no complaints of pain or subjective restriction of mouth opening. One patient recorded TMJ clicking. No patient reported tenderness upon palpation of the joint area. The mean maximum mouth opening was mm (range 33 58) in two patients with a slight deviation to the fractured side. The mean maximum protrusive movement was 7.88 mm, and the mean maximum laterotrusive movement to the side of fracture and to the contralateral side was 7.80 mm (range ) and 8.32 mm (range ), respectively (Table 2). The degree of jaw mobility in the three types of fractures was similar. A chin point deviation in the centric occlusion to the fracture side was observed in one patient and the non-injured side in one. A midline deviation in the dentition to the injured side was registered in one patient and to the non-injured side in one case. There was no clear relationship with the type of fracture (Table 3). Fig. 2. Measurement of deviation of the symphysis. Fig. 3. Illustration of TMJ measurements.

4 854 Choi et al. Table 2. Mean values (mm) and standard deviations for mandibular mobility Table 3. Clinical evaluation of TMJ and growth disturbance Clinical findings Unilateral fracture (N =8) Complete clinical and functional recovery was observed in all patients, while a slight facial asymmetry remained in two patients. Two patients showed malocclusion and one patient had orthodontic treatment. On orthopantomogram, the non-surgical treatment resulted in a healing process leading to a normal condyle and condylar neck. This favorable healing process occurred in 5 (63%) of the patients. In 37%, the restoration of the condyle to a normal form had not occurred completely (Fig. 4). However, this had no functional or aesthetic consequences. A difference in length between the fractured and contralateral ascending ramus was observed in five patients (63%; Table 4). The frequency of the abnormalities determined by CT analysis is summarized in Table 5. The shape of the fractured condyles varied: three were ellipsoid, seven were concavoconvex and one case was ovoid. The remaining patient had variable shapes. Differences in the condylar angles of the fractured and non-fractured sides, which indicated a deviation of the condylar axis, were noted in four patients. Three (37.5%) condylar heads were displaced anterior to the glenoid fossa. Flattening Unilateral fracture (N =8) of the articular eminence was noted in four joints (50%) (Table 5). Six out of eight patients (75%) showed no facial asymmetry. In two patients, a slight facial asymmetry remained, which was of no concern to the patient. Bilateral condylar fractures Bilateral fracture (N =3) Maximal opening (8.87) 45.0 (2.12) Lateral excursion Right 7.80 (2.46) 9.67 (0.58) Left 8.32 (2.27) 8.0 (1) Protrusion 7.88 (2.85) 6.83 (0.29) Bilateral fracture (N =3) Deviation of Mn. midline in C.O 2 (25%) 0 Deviation of midline during M.O 2 (25%) 1 Noises in joint 1 (12.5%) 0 TMJ pain during mouth opening 0 0 TMJ pain during palpation 0 1 Malocclusion 2 (25%) 2 Facial asymmetry 2 (25%) 1 Table 4. Difference in ramal height among patients with unilateral condylar fractures Degree of difference in ramal height Fracture type N None Mild Severe Low condylar neck High condylar neck Intracapsular Total None; 0 2 mm mild; 2 4 mm severe; >4 mm. Only three patients sustained bilateral condylar fractures (one boy, two girls; mean age years, range years). One patient had high condylar fractures on both sides. In the other two patients, an intracapsular fracture on one side was combined with a low and high condylar neck fracture on the other side, respectively. Two patients had associated fracture of the symphysis. The mean follow-up period was 4.17 years (range years) and the mean age at the follow-up was years (range ). There were no complaints of pain or restriction in mouth opening. One patient reported TMJ clicking, and another reported tenderness upon palpation of the joint area (Table 3). The mean maximum mouth opening was 45 mm, and deviation from the midline was observed in one patient. The mean maximal protrusive movement was 6.83 mm and the mean maximal laterotrusive movement to both sides was 9.67 mm on the right side, and 8.0 mm on the left (Table 2). Complete clinical recovery was observed in all bilateral cases. Signs of facial asymmetry were observed in one case and slight retrognathia with a class II malocclusion were noted in two patients. However, there was no open-bite. In one patient, a small midline deviation of the dentition was present. In two patients, a restoration of the normal shape of the condyle was achieved. However, in one patient, a shortening of 3 mm on the right side was observed (Fig. 5) The 3-D reconstruction of the one patient showed a deformed and hyperplastic condyle. The remodeled condylar head was located more anteriorly than on the contralateral side. The condyle was dislocated moderately anteriorly and some asymmetry was noted (Fig. 5). The other two cases showed an almost normal TMJ structure, except for a slight flattening of the temporal bone. Table 5. Radiographic findings on 3-D CT scans in 9 patients with 12 fractured condyles Frequency Percentage Shape Ellipsoid Concavo-convex Ovoid Other Alteration in shape Deformed Hypoplastic Hyperplastic Cortical irregularity 8 67 Condylar angle compared with the normal side (n = 8) 4 50 Condyle position 3 25 Flattening of glenoid fossa and articular eminence 4 50

5 A follow-up study of condyle fracture in children 855 Fig. 4. TMJ images of a 15-year-old female who sustained left high condyle neck fracture at the age of 13. (A) Coronal plane CT image showing high condyle neck fracture immediately after trauma. (B) Axial 3-CT scan: axial view shows ovoid shape and hypoplastic condyle compare to normal right condyle. Discussion Several investigators have reported the treatment results of condylar fractures in children. In general, satisfactory treatment results have been observed following condylar fractures in children. However, THO- REN et al. 18 reported that more than half of their patients had subjective symptoms and almost two thirds showed clinical signs of dysfunction. In this study, regarding the functional clinical evaluation, good recovery of the TMJ function was noted in unilateral and bilateral fracture. In the conservative treatment of fractured condyle in children, GUVEN & KESKIN 5 report that their patients were treated by custom made arch bars and intermaxillary fixation for days. And each patient then underwent a functional treatment consisting of passive mouth opening exercise. THOREN et al. 18 stated that some patients had no treatment and were given dietary restriction only, and others had intermaxillary fixation for days. HOVINGA et al. 6 also stated that the treatment consisted of reassurance and explanation, and in some cases, in which the proper occlusion could not be reached initially, two weeks of MMF followed by guiding elastics were applied. STROBL et al. 16 reported that the patients were treated in a nonsurgical-functional fashion for a period of four to six months, using an intraoral, myofunctional activator without the additional use of preceding MMF. However, SAHM &WITT 15 stated that all patients in their study received IMF for 2 3 weeks and after that were treated with a removable functional orthopaedic appliance. In this study, a short period of intermaxillary fixation was used where there was excessive pain and/or persistent malocclusion (Table 1), all patients received active physical exercise using rubber elastic traction. Five patients had no IMF and were given physical therapy only. The remaining six had IMF for 2 10 days (mean: 4.8 days). Six additional fractures were treated with acrylic resin splint and circum-mandibular wiring and one mandibular symphysis fracture with miniplate osteosynthesis. GUVEN &KESKIN 5 suggested that a measurement of the maximal interincisal distance is a very good indicator of the TMJ function, and a difficulty in mouth opening is accompanied by other TMJ dysfunctions such as limited lateral, anterior and posterior excursions of the mandible and poor mastication. They report that the average maximum interincisal distance on mouth opening was 38.3 mm ranging from 34 to 43 mm. The average maximum mouth opening in our patients was mm in those with unilateral fractures and 44.3 mm in those with a bilateral fracture. These findings are comparable with other studies: CASCONE et al. 1 reported 44.3 mm and HOVINGA et al. 6 reported 49.3 mm. GUVEN & KESKIN 5 reported that the average lateral movement to the side of fracture and to the contralateral side was 8.4 and 7.8 mm, respectively. CASCONE et al. 1 reported that the lateral movement values recovered to 9.3 mm for the right side and 9.2 mm for the left side. The results of the current follow-up evaluation are similar to those reported in other studies. KAHL-NIEKE et al. 8 stated the clinical criteria for a follow-up evaluation. Based on their cri-

6 856 Choi et al. Fig. 5. TMJ images of a 15-year-old female who sustained a dislocated high condyle neck fracture of the right and displaced high condyle neck fracture of the left at the age of 11. (A) Coronal CT image and (B) panoramic radiograph show bilateral fracture immediately after trauma. (C) Severe deformity of the right condyle after follow-up period of 4 years in same patient. (D and E) 3-D reconstruction of right and left TMJ viewed from infero-lateral aspect; the right is hypoplastic and deformed.

7 A follow-up study of condyle fracture in children 857 teria, the clinical results of this study are favorable and satisfactory. MCGUIRT 11 reported that 13 out of the 28 (46%) subjects reported TMJ popping noises, and 5 of these 13 complained of discomfort when they yawned or opened their mouths widely. HOVINGA et al. 6 stated that TMJ function was undisturbed in all of his patients. STROBL et al. 16,GUVEN & KESKIN 5, and THOMPSON et al. 17 reported that the symptoms and signs of a dysfunction were very slight. In this study, clicking of the joint was observed in one case with unilateral fracture and TMJ tenderness to palpation existed in another case with a bilateral fracture, which is consistent with the long-term findings of the TMJ function from other authors. Numerous reports on mandibular growth following pediatric condylar fracture suggest that non-surgical management produces satisfactory results. LUND 10 reported six patients (22%) showed evidence of retarded growth on the fractured side. GILHUUS-MOE 4 found a deviation of the mandible toward the fractured side in 14 out of 43 patients with unilateral fractures (33%). He also reported an overgrowth of the fractured condyle. HOVINGA et al. 6 stated that a considerable growth disturbance was observed in two patients in their study. THOMPSON et al. 17 identified seven class II malocclusion and one open bite in 23 cases. From this study, there were two patients with unilateral fractures who had a malocclusion and somewhat facial asymmetry. Two out of three bilateral condylar fractures had a slight malocclusion and one patient showed facial asymmetry. The results might show that a growth disturbance was more frequent when associated with bilateral condylar fractures. This is in accordance with the results reported by THOMPSON et al. 17. HOVINGA et al. 6 reported that 54.5% of the unilateral and 83.3% of the bilateral fractures did not show any growth disturbance. They showed that low condylar and intracapsular fractures gave rise to the largest number of facial asymmetries. This study was unable to show any correlation between the type of condyle fracture and the growth disturbance, which will be examined in a further investigation. In this study, of five patients with facial asymmetry or malocclusion, four patients had additional fracture of mandible. Nearly all the patients with facial asymmetry or malocclusion had other fracture of the mandible, which might be another factor that contribute to these problems. Because of relatively small size of our study population, we were unable to relate their problems and associate fracture of the mandible. Ankylosis of the TMJ is an extremely rare and a serious complication of a condylar fracture but there was no ankylosis noted in this series Regarding the relationship between age and the remodeling capacity, DAHLSTRÖM et al. 2 reported that almost twice as many subjects in the oldest group experienced symptoms of dysfunction. In 1997, DIMI- TROULIS 3 reported that a favorable outcome was most likely to occur in patients under 10 years of age where the remodeling potential was greatest, and in some postpubertal adolescents, dysplastic growth might occur, whereby the growth of the mandible may become progressively asymmetrical as a result of a reduced growth and remodeling potential on the side of the fractured mandibular condyle. ROWE 14 stated that injuries inflicted before 3 years of age will produce a severe asymmetric deformity; those inflicted after 6 years of age, a moderate deformity; and those after 12 years of age, only slight deformity. LINDAHL &HOLLENDER 9 compared the process of remodeling the condylar after a fracture in children and adults, and reported that between 3 and 11 years of age, extensive remodeling of the condylar fractures generally resulted in a normal anatomy. NORHOLT et al. 12 also found that younger children had fewer long-term problems from their injuries than their older counterparts. It was not possible to demonstrate any correlation between the age and the remodeling capacity in this study. In general, a tendency toward an increasing possibility of dysplastic growth with increasing age at the time of trauma was noted. In the past, a morphologic evaluation has been based primarily on the panoramic radiographic film. In this study, on the orthopantomogram, the ramus height was measured and the shape of the condyle was compared with that on the nonfractured side. Bilateral fractures were judged as either being normal or having persistent signs of the earlier fracture. Using panoramic radiographs, GUVEN & KESKIN 5 reported that the remodeling of the condyle head was good in 17, while moderate remodeling occurred in the other four condyles. Three out of eight unilateral condyle fracture patients did not show any difference in the ramus height in this study, five patients showed mild differences (4 mm) in the ramus height and none of these patients showed severe difference (4 mm). Nowadays, CT scanning plays a key role in assessing the condylar state and the position after fractures as well as in diagnosis. Computed tomography (CT) offers the possibility of examining the state of the TMJ without a superimposition of the adjacent structures. Recent developments in CT technology have enabled excellent 2-D and 3-D reformatted images in different anatomic planes to allow a detailed examination. From this study, 3-D CT imaging appears to be a valuable diagnostic aid in cases of condyle fractures where severe morphological changes were not recognized in earlier conventional X- ray examinations. It was possible to evaluate both quantitatively and qualitatively the effects of treatment on the condyle size and shape, sclerosis and cortical irregularities, condylar and intercondylar angle, joint position, neck length, depth of glenoid fossa, and flattening of the articular eminence. A similar view was expressed by SAHM &WITT 15 and KAHL et al. 7. In 1995, using 3-D CT, KAHL et al. 7 reported that 11 patients with 13 different types of condyle fractures showed a restoration of the normal function with a favorable remodeling and the remaining eight patients had only a good function with a deformed condyle and significant asymmetry in the condylar angle and length of the condylar neck. From the results of this study, 25% of the patients showed a change in the condyle position, 50% had asymmetric condylar angles and eight condyles showed abnormal shapes. Despite the apparent excellent functional recovery, there was marked remodeling changes evident on the CT scan. Such changes were not usually evident on the panoramic radiograph. Several examples of a bifid condyle were reported in the literature 11,12. Many authors, such as LUND 10 and LINDAHL & HOLLENDER 9, suggested it to be caused by an insufficient remodeling capacity or by an abnormal growth generated by the position of the articular disc. In this series, one patient, who sustained bilateral condyle fractures, showed bony exostosis of the condyle head (Fig. 5). The remodeling process after a condylar fracture is not limited to the condyles but also involves a flattening of the mandibular fossa. This was histologically demonstrated proved by GILHUUS-MOE 4 using animal experiments. Similar observations were reported by THOMPSON et al. 17,LIN- DAHL &HOLLENDER 9 and SAHM &WITT 15 in their studies of condylar fracture in children. There were four cases of a slight glenoid flattening in this study. In cases where there was a significant difference in the ramus height with a consequent resorption of the proximal segment, the facial

8 858 Choi et al. asymmetry appears to be less conspicuous with a relatively low frequency of TMJ symptoms. In conclusion, non-surgical treatment of dislocated condylar process fractures in children has satisfactory long-term outcome of jaw function despite the high frequency of radiologically noted aberrations. Serious growth disturbances are rare, but cannot be predicted based on the fracture type. These results are in accordance with other studies, and confirm that conservative treatment is preferred when condylar fractures occur in children. References 1. Cascone P, Sassano P, Spallaccia F, Rivaroli A, Paolo CD. Condylar fractures during growth: follow-up of 16 patients. J Craniofac Surg 1999: 10: Dahlström L, Kahnberg KE, Lindahl L. 15 years follow-up on condylar fractures. Int J Oral Maxillofac Surg 1989: 18: Dimitroulis G. Condylar injuries in growing patients. Aust Dent J 1997: 42: Gilhuus-Moe O. Fractures of the mandibular condyle in the growth period. Histologic and autoradiographic observations in the contralateral, nontraumatized condyle. Acta Odontol Scand 1971: 29: Guven O, Keskin A. Remodelling following condylar fractures in children. J Craniomaxillofac Surg 2001: 29: Hovinga J, Boering B, Stegenga B. Long-term results of nonsurgical management of condylar fractures in children. Int J Oral Maxillofac Surg 1999: 28: Kahl-Nieke B, Fischbach R, Gerlach KL. CT analysis of temporomandibular joint state in children 5 years after functional treatment of condylar fractures. Int J Oral Maxillofac Surg 1994: 23: Kahl B, Fischbach R, Gerlach KL. Temporomandibular joint morphology in children after treatment of condylar fractures with functional appliance therapy: a follow-up study using spiral computed tomography. Dentomaxillofac Radiol 1995: 24: Lindahl L, Hollender L. Condylar fractures of the mandible: a radiographic study of remodelling processes in the temporomandibular joint. Int J Oral Surg 1977: 6: Lund K. Mandibular growth and remodelling processes after condylar fracture: a longitudinal roentgen cephalometric study. Acta Odontol Scand 1974: 32(Suppl. 64): McGuirt WF, Salisbury III PL. Mandibular fractures: their effect on growth and dentition. Arch Otolaryngol Head Neck Surg 1987: 113: Norholt SE, Krishnan V, Sindet- Pedersen S, Jensen IB. Pediatric condylar fractures: a long-term follow-up study of 55 patients. J Oral Maxillofac Surg 1993: 51: Proffit WR, Katherine WL, Turvey TA. Early fractures of the mandibular condyles: frequently an suspected cause of growth disturbances. Am J Orthod 1980: 78: Rowe NL. Fractures of the jaws in children. J Oral Surg 1969: 27: Sahm G, Witt E. Long-term results after childhood condylar fractures. A computer-tomographic study. Eur J Orthodont 1989: 11: Strobl H, Emshoff R, Rothler G. Conservative treatment of unilateral condylar fractures in children: a long-term clinical and radiologic follow up of 55 patients. Int J Oral Maxillofac Surg 1999: 28: Thompson HG, Farmer AW, Lindsay WK. Condylar neck fractures of the mandible in children. Plast Reconstr Surg 1964: 34: Thoren H, Iizuka T, Nurminen M, Lindqvist C. An epidemiologic study of patterns of condylar fractures in children. Br J Oral Maxillofac Surg 1997: 35: Topazian RG. Etiology of ankylosis of temporomandibular joint: analysis of 44 cases. J Oral Surg 1964: 22: Address: Jinho Choi Department of Dentistry College of Medicine Inha University rd ST Shinheung-Dong Choong-Gu Inchon Korea Tel: /1 Fax: jinho98@inha.ac.kr