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Different patterns of mandibular fractures in children. An analysis of 220 fractures in 157 patients
Journal of Cranio-Maxilto-Focial Surgery (1992) 20, 292 296 ,~ 1992 European Association for Cranio-Maxillo-Facial Surgery
Different patterns ol manaibular Iractures in chllaren. An analysis oI 220 fractures in 157 patients Hanna Thor6n 1, Tateyuki Iizuka 1, Dorrit Hallikainen2, Christian Lindqvistz
1Department of Oral and Maxillofacial Surgery (Head: C. Lindqvist, MD, DDS, PhD), IV Department of Surgery, Helsinki University Central Hospital, Helsinki, 2Department of Radiology (Head: J. Edgren, MD, PhD), IV Department of Surgery, Helsinki University Central Hospital, Helsinki, Finland
S U M M A R Y. 157 paediatric patients with a total of 220 mandibular fractures were evaluated retrospectively. All patients had been examined with the aid of orthopantomography. 72 % of the children had fractures in the condylar region. The patients were divided into four age groups according to the development of the dentition (group A: 05 years, B: 6-9 years, C: 10-12 years, and D: 13-15 years). Bicycle accidents and falls were the two main causes of the fractures in all age groups. However, there were significant differences in the causes and location of the fractures between groups A ÷ B and C + D. The proportion of condylar fractures decreased and the proportion of body and angle fractures increased with increasing age; fractures in the horizontal part of the mandible were mainly observed in groups C and D. Both aetiological factors and fracture patterns in the patients older than 10 years of age resembled those of adults. The differences observed should be taken into consideration in studies concerning mandibular fractures in paediatric patients. In this respect the age limit between the adult and child should probably be lowered significantly.
KEY WORDS: Children - MaxiUofacial injuries - Mandibular fractures
INTRODUCTION
both mandibular and midfacial fractures. Although problems related to the lower and middle third fractures are different, there are only a few detailed analyses exclusively concerning mandibular fractures. We chose to study mandibular fractures exclusively in order to analyze the role of the growing mandible and the dental development on the fracture pattern.
Most facial trauma occurs in young adults (Lamberg, 1978; Bochlogyros, 1985; Ellis et al., 1985; Haymond et al., 1988; Cook and Rowe, 1990). However, maxillofacial fractures in children are rare. In Rowe's analysis of 1500 fractures, less than 5% of the fractures were in children younger than 12 years of age (Rowe, 1968). A low incidence has been presented in other studies too, (Hagan and Huelke, 1961; Oikarinen and Malmstr6m, 1969; Lamberg, 1978; Khan, 1988; Sawhney and Ahuja, 1988; Kotilainen et al., 1990; Zachariades et al., 1990). The low incidence has been explained by certain characteristics of the child: in infants and younger children the face is smaller in proportion to the head size and the prominent frontal cranium shields the facial skeleton, thus protecting it from trauma. In McGraw and Cole's (1990) study, the fractures shifted from the upper to the lower region of the face with increasing age; mandibular fractures were more prevalent in the older age groups and frontal and orbital fractures occurred more frequently in the youngest age group (McGraw and Cole, 1990). Small paranasal sinuses and great elasticity of the bone are also characteristic of young children and provide resistance to fracturing. 75-90% of jaw fractures in children occur in the mandible (Andersson et al., 1989; Zachariades et al., 1990; Stylogianni et al., 1991). Studies concerning paediatric maxillofacial trauma have usually included
PATIENTS AND METHODS The present study included 157 patients under 16 years of age, with mandibular fractures treated in the Department of Oral and Maxillofacial Surgery, Helsinki University Central Hospital, Finland, during the 10-year period 1980-1989. The patient records and all available documents and X-rays were reviewed. The data included age at the time of injury, mechanism of injury, anatomical site of fracture, associated injuries and treatment methods. In addition, the fracture lines available from panoramic images (orthopantomographs) were drawn on separate figures to illustrate the patterns of mandibular injuries. In cases in which radiographs were not available (35) the fracture lines were drawn according to the X-ray protocols made by a radiologist. The patients were divided into four age groups (group A: 0-5 years, group B: 6-9 years, group C:10-12 years and group D:13-15 years) according to 292
Mandibular fractures in children
the development of the dentition. In general, the age range of group A is regarded as the period of the decidous dentition, that of group B as the first eruption period, that of group C as the second eruption period and the age range of group D as the stage of the permanent dentition (Hurme, 1945; Haavikko, 1970). Similarities and differences in the cause and type of injuries were compared in relation to these age groups.
RESULTS Of the total of 157 children 107 were boys and 50 girls with a mean age of 8.4 years (range 1 through 15 years). The age and sex distribution are given in Figure 1. More than one third of the patients belonged to the oldest age group (37.6 %) and only 19 children were younger than 6 years of age (12.1%). Groups B and C (6-9 and 10-12 years) were about the same size, 24.2 % and 26.1%, respectively. There was an overall 2: l boy-girl ratio and a male preponderance in all age groups (Fig. 1).
related. All patients with mandibular fractures caused by motor-bike accidents and 85.7 % of the patients with fractures caused by violence were boys. Table 2
[
Group A
Group B
Group C
Group D
10 11 '~2
13 14 15
¢n E o o
10
0 1
2
3
4
5
6
7
8
9
age (years) •
Yearly and monthly distribution of accidents
Boys
Gids
E~
Fig, l Age and sex distribution of 157 children with 220 mandibular fractures.
The yearly number of children with mandibular fractures in our sample from the Helsinki area ranged from 9 (5.7% of the total) in 1984 to 25 (15.9% of the total) in 1982. The incidence of accidents correlated significantly with the time of the year: more than half of all accidents occurred during the period MaySeptember (66.9 %) (Fig. 2). _=
Causes of injury The causes of the mandibular fractures are shown in Table 1. The most common mechanism of injury was a road traffic accident (RTA) (57.3 %). The majority of the RTA's were connected with cycling; 61 patients, 38.9 % of the whole material, suffered their injury this way. This was the most frequent aetiological factor in all age groups. Motorbike, car, and car-pedestrian accidents accounted for 18.4% of the injuries. Falls, 17.8 %, were nearly as common an aetiological factor and 10.8 % of the cases were connected with sports activities such as horse-back riding, skiing, contact sports, or ball-games. Violence was the cause of fractures in 14 cases (8.9 %). In age groups A and B (the under ten's) RTA's and falls were the two main causes of the fractures (for all children in group A and in 94.7 % of the cases in group B). In groups C and D the aetiology of the trauma was more variable. In these age groups only 63 % of the children had fractures that were caused by RTA or falls. Cycling as an aetiological factor decreased from 52.6 % in group A to 23.7 % in group D. Of the total of 11 motorbike accidents, 10 (90.9 %) occurred in age groups C and D. All the sports-related injuries and 92.8 % of the violence-associated trauma occurred in children over 10 years of age. The distribution of the causes of the injuries were sex-
293
20
i
"6
o_ 10
0
i
i
JAN ~ MIR A;R M~Y J~ JOL ~
~
d~ ~
month
Fig. 2 - Monthly distribution of accidents.
Table 1 - Causes of 220 mandibular fractures in 157 children
Type of accident
No. of patients
%
Road traffic accidents car bicycle motorbike auto-pedestrian Fall Sports Violence Hit by object Gunshot Total
90 9 61 l1 9 28 17 14 7 1 157
57.3 5.7 38.9 7.0 5.7 17.8 10.8 8.9 4.5 0.6 100
294
Journal of Cranio-Maxillo-Facial Surgery
Table 2 - Comparison of clinical features related to paediatric mandibular fractures in relation to the four age groups (in %) Group A Group B Group C Group D Aetiology bicycle fall sports violence motorbike car car-pedestrian bit by object gunshot Total Type of fracture condylar symphysis angle body alveolar ramus Total Midfacial fractures Treatment observation operative
52.6 36.8 0 0 0 5.3 5.3 0 0 100
52.6 23.7 0 2.6 2.6 7.9 7.9 2.6 0 100
41.5 17.1 19.5 0 4.9 7.3 0 7.3 2.4 100
23,7 8,5 15,3 22,0 13.6 3.4 8.5 5.1 0 100
76.0 8.0 4.0 0 12.0 0 100 0
63.6 18.2 3.6 9.1 5.4 0 100 7.9
63.8 12.1 8.6 10.3 3.4 1.7 100 9.8
50.0 15.5 17.1 11.0 2.4 3.7 100 15.2
84.2 10.5
55.3 10.5
53.7 9,8
35.6 18.6
shows the distribution of aetiological factors for each age group.
Injuries A total of 220 mandibular fractures were diagnosed in the 157 patients. A majority of the fractures (60%)
occurred in the condyler region. The next common fracture site (14.5 %) was the mandibular symphysis, defined as the region between the canines, followed by the angle (10%) and body regions (9.1%). Four (1.8 %) fractures were found in the mandibular ramus. 104 patients (66.2%) had only 1 fracture, 42 (26.7 %) had 2 and 11 (7 %) had 3 or more fractures in the mandible. Condylar fractures were diagnosed in 113 (72%) patients. Of these 94 had a unilateral condylar fracture (83.2%) and 19 (16.8%) suffered from bilateral fractures. In 27 patients (17.2%) the condylar fractures were associated with fractures of other regions (mostly the symphysis region). 10 patients had dentoalveolar fractures. Seven (4.5%) had dentoalveolar fractures only and in 3 cases mandibular fractures of other regions were also diagnosed. Of all injuries, condylar fractures were the most common in all age groups (76 % in group A, 63.6 % in group B, 63.8 % in group C, and 50 % in group D). However, the relative frequency of condylar fractures decreased and those of the body, angle, and ramus increased with increasing age. Fractures in the body, angle, and ramus regions occurred less frequently in patient groups under 10 years of age as compared with the older age groups (Figs 3 and 4). Body fractures constituted 10.3 % of the fractures in group C and 11% in group D but in only 6.2 % of all fractures in groups A and B. There were no significant differences in the frequency distribution of symphysis fractures between age groups A + B , C and D (Table 2). Associated fractures in the midface were diagnosed in
Fig. 3 - The mandibular fracture lines in children in groups A and B (under l0 years) drawn from orthopantomographs.
Fig. 4
The mandibular fracture lines in children in groups C and D (10-15 years) drawn from orthopantomographs.
Mandibular fractures in children Table 3
295
Maxillofacial fractures in children; a review of the literature
Reference
Age limit (years)
Total material (patient no.)
Children (%)
Anatomical area studied
Study period
Rowe 1968 Oikarinen and M a l m s t r 6 m 1969 Bochlogyros 1985 K h a n 1988 H a g a n and Hulke 1961 Ellis et al. 1985 Rowe 1968 Zachariades et al. 1990 Lamberg 1978 Lamberg 1978 Sawhney and Ahuja 1988 Kotilainen et al. 1990 Present study
< < < < < < < < < < < < <
1500 1284 853 311 319 2137 1500 3908 704 475 262 350 2050
0.9 3.7 6.1 1.3 6.3 1.8 4.9 5.2 5 4 9.2 5.7 7.7
facial bones facial bones mandible facial bones mandible mandible facial bones facial bones mandible midface facial bones facial bones mandible
1948-1966 1958 1967 1960 1980 1985-1986 1948-1958 1974~1983 1948-I966 1960-1984 1969-1975 1969-1975 1982-1983 1980-1984 1980-1989
6 10 10 10 11 i1 12 15 16 16 16 16 16
13 patients and these were most frequently observed in group D (8 patients) (Table 2). Nearly all of these patients were males (84.6 %). Three patients had an additional skull fracture. Cerebral injuries such as commotio cerebri or contusion were diagnosed in 17 patients, fractures of the upper and/or lower extremities in 11, a hip fracture in 2, and a pneumothorax in 1 patient. Treatment
In half of the patients (51.6%), treatment of the mandibular fractures was confined to observation only. Rigid IMF was used in 61 cases and the duration of IMF was 21 days on average (range ~ 3 5 days). Three patients were treated by the use of elastic IMF alone. In 15 patients, arch bars for IMF were applied under general anaesthesia or sedation because of poor cooperation. Of the patients in group A, 84.2 % were treated by observation and soft diet alone, the corresponding figure being 55.3 % for group B, 53.7 % for group C and 35.6% for group D. 21 patients (13.4%) underwent open reduction and osteosynthesis. The fixation of fractures was performed using transosseous wiring in 17 and miniplates in 3 cases. In all patients treated by transosseous wiring or miniplates, IMF was used postoperatively for 24 weeks. In only 1 patient (a 12-year-old boy), a fracture of the symphysis region was stabilized with an AO rigid plate (Table 2). DISCUSSION The Department of Oral and Maxillofacial Surgery, Helsinki University Central Hospital, Finland, is the only unit in the Helsinki area which treats mandibular fractures, and serves a population of about 1.5 million. The present material can be considered to cover the mandibular fractures needing either consultation or active therapy that occurred in this area between 1980-1989. There are numerous reports on maxillofacial trauma in children. (Rowe, 1968; Amaratunga, 1988; Harrington et al., 1988; Uji and Teramoto, 1988; Andersson et al., 1989; Kotilainen et al., 1990; McGraw and Cole, 1990; Zachariades et al., 1990; Stylogianni
et al., 1991). In general, maxillofacial fractures seem to occur infrequently in paediatric patients (Table 3). The proportion of children younger than 6 years is approximately 1% of all patients with mandibular fractures (Hagan and Huelke, 1961 ; Rowe, 1968), and only 2-6% of fractures occur before the age of 10 (Hagan and Huelke, 1961 ; Oikarinen and Mahnstr6m, 1969; Bochlogyros, 1985). The incidence found in the present survey, 7.7% in children younger than 16 years and 2.9 % in children younger than 10 years, are close to those previously reported. The variation in the incidence and age distribution might be related to the socio-economic status of the different countries concerned. In Finland, the percentage of children with mandibular fractures has increased slightly over the past two decades (Lamberg, 1978). This may be attributable to the change in the age structure and an increase in the population in the Helsinki area. The results of this study showed that falls and bicycle accidents were the two main causes of mandibular fractures in the under 10 years age groups, but clear aetiological variations were observable in the older patient groups. This is probably caused by the fact that the lifestyle of children changes when they reach the second decade. An important finding of this study is the predominance of bicycle accidents (38.9 %) especially in the youngest age group (52.6 %). This result suggests that with respect to children cycling, more attention should be paid to protective and preventive measures. All cyclists should always wear safety helmets that cover the chin so that the condylar processes are protected (Lindqvist et al., 1986). Parents should be made aware of the hazards of cycling; young children are not able to cope with traffic, and some of the accidents on playing grounds might be avoided with more caution. Violence is the main aetiology of maxillofacial fractures in adults. The results of this study showed that children of 1315 years are already prone to receive mandibular fractures when assaulted. The prevention of violence through education in schools is therefore of major importance, in order to decrease the incidence of facial injuries in youngsters. A clear predominance of condylar fractures was found in all four age groups. However, the characteristics of the fracture location also reflected some
296
Journal of Cranio-Maxillo-Facial Surgery
differences between the age groups; most cases of mandibular body and angle fractures were diagnosed in patients over 10 years of age, and condylar fractures had a decreasing incidence with age. It seems that the fracture location in children over 10 years of age gradually assumes a pattern similar to that in adults. Treatment of mandibular fractures in children is usually conservative and is often restricted to intermaxillary fixation only. (Amaratunga, 1987; Crockett et al., 1989; Jamerson and White, 1990). The indications for surgical treatment are limited. One reason is the growing mandible which might be disturbed by open surgery and osteosynthesis, Another reason is the lack of space for osteosynthesis material due to the presence of developing tooth follicles in the mixed dentition. An additional explanation is that the majority of the fractures (60%) in this age group, and especially in patients under 10 years of age, were condylar fractures which are usually treated conservatively. In studies concerning maxillofacial trauma in children, the upper age limit varies from 11-20 years (Amaratunga, 1988; Uji and Teramoto, 1988; Andersson et al., 1989; Kotilainen et al., 1990; McGraw and Cole, 1990; Zachariades et al., 1990; Stylogianni et al., 1991). The criteria for defining the age groups are often unclear. According to the results of this study, a decisive limit seems to be 10 years of age. After this age the aetiologies and fracture types become similar to those in young adults. The differences between the first and second decade should be taken into consideration in studies concerning diagnosis and treatment of mandibular fractures in paediatric patients.
References Andersson, L., M. Hultin, O. Kjellman, A. Nordenram, G. Ramstrdm: Jaw fractures in the county of Stockholm (1978-1980). Swed. Dent. J. 13 (1989) 201 Amaratunga, N. A. de S: The relation of age to the immobilization period required for healing of mandibular fractures. J. Oral Maxillofac. Surg. 45 (1987) 111 Amaratunga, de S. N. A.." Mandibular fractures in children. A study of clinical aspects, treatment needs, and complications. J. Oral Maxillofac. Surg. 46 (1988) 637 Bochlogyros, P. N. : A retrospective study of 1521 mandibular fractures. J. Oral Maxillofac. Surg. 43 (1985) 597 Cook, H. E., M. Rowe: A retrospective study of 356 midfacial
fractures occurring in 225 patients. J. Oral Maxillofac. Surg. 48 (1990) 574 Crockett, D. M., R. P. Mungo, R. E. Thompson: Maxillofaciai trauma. Pediatr. Clin. North Am. 36 (1989) 1471 Ellis, E., K. F, Moos, A. El-Attar: Ten years of mandibular fractures: An analysis of 2137 cases. Oral Surg. 59 (1985) 120 Haavikko, K. : The formation and the alveolar and clinical eruption of the permanent teeth. An orthopantomographic study. Proc. Finn. Dent. Soc. 66 (1970) 103 Hagan, E. H., D. F. Huelke: An analysis of 319 case reports of mandibular fractures. J. Oral Surg. 19 (1961) 93 Harrington, M. S., A. B. Eberhart, J. F. Knapp : Dentofacial trauma in children. ASDC J. Dent. Child. 55 (1988) 334 Haymond, C., C. Nicholson, H. A. Kiyak, D. Trimble : Age differences in responses to facial trauma. Spec. Care Dentist 8 (1988) 115 Hurme, V. 0.: Ranges of normalcy in the eruption of permanent teeth. ASDC J. Dent. Child. 16 (1949) 11 Jamerson, R. E., J. A. White: Management of pediatric mandibular fractures. J. LA State Med. Soc. 142 (1990) 11 Khan, A, A. : A retrospective study of injuries to the maxillofacial skeleton in Harare, Zimbabwe. Br. J. Oral Maxillofac. Surg. 26 (1988) 435 Kotilainen, R., J. Kiirj& A. Kullaa-Mikkonen : Jaw fractures in children. Int. J. Pediatr. Otorhinolaryngol. 19 (1990) 57 Lamberg, M. : Maxillofacial fractures. An epidemiological and clinical study on hospitalized patients. Proc. Finn. Dent. Soc. 74 Suppl. VII (1978) Lindqvist, C., S. Sorsa, T. Hyrkiis, S. Santavirta: Maxillofacial fractures sustained in bicycle accidents. Int. J. Oral Maxillofac. Surg. 15 (1986) 12 McGraw, B. L., R. R. Cole: Pediatric maxillofacial trauma. Arch. Otc,laryngol. Head Neck Surg. 116 (1990) 41 Oikarinen, V., M. Malmstr6m: Jaw fractures. Proc. Finn. Dent. Soc. 65 (1969) 95 Rowe, N. L. : Fractures of the facial skeleton in children. J. Oral Surg. 26 (1968) 505 Sawhney, C. 0., R. B. Ahuja: Faciomaxillary fractures in north India, A statistical analysis and review of management. Br. J. Oral Maxillofac. Surg. 26 (1988) 430 Stylogianni, L., A. Arsenopoulos, A. Patrikiou : Fractures of the facial skeleton in children. Br. J. Oral Maxillofac. Surg. 29 (1991) 9 Uji, T., T. Teramoto: Occurrence of traumatic injuries in the oromaxillary region of children in a Japanese prefecture. Endod. Dent. Traumatol. 4 (1988) 63 Zachariades, N., D. Papavassiliou, F. Koumoura : Fractures of the facial skeleton in children. J. Cranio-Max.-Fac. Surg. 18 (1990) 151
Hanna Thor6n, DDS Department of Oral and Maxillofacial Surgery IV Department of Surgery Helsinki University Central Hospital Kasarmink. 11-13 SF-00130 Helsinki 13, Finland Paper received: 11 January 1992 Accepted: 31 March 1992
Different patterns ol manaibular Iractures in chllaren. An analysis oI 220 fractures in 157 patients Hanna Thor6n 1, Tateyuki Iizuka 1, Dorrit Hallikainen2, Christian Lindqvistz
1Department of Oral and Maxillofacial Surgery (Head: C. Lindqvist, MD, DDS, PhD), IV Department of Surgery, Helsinki University Central Hospital, Helsinki, 2Department of Radiology (Head: J. Edgren, MD, PhD), IV Department of Surgery, Helsinki University Central Hospital, Helsinki, Finland
S U M M A R Y. 157 paediatric patients with a total of 220 mandibular fractures were evaluated retrospectively. All patients had been examined with the aid of orthopantomography. 72 % of the children had fractures in the condylar region. The patients were divided into four age groups according to the development of the dentition (group A: 05 years, B: 6-9 years, C: 10-12 years, and D: 13-15 years). Bicycle accidents and falls were the two main causes of the fractures in all age groups. However, there were significant differences in the causes and location of the fractures between groups A ÷ B and C + D. The proportion of condylar fractures decreased and the proportion of body and angle fractures increased with increasing age; fractures in the horizontal part of the mandible were mainly observed in groups C and D. Both aetiological factors and fracture patterns in the patients older than 10 years of age resembled those of adults. The differences observed should be taken into consideration in studies concerning mandibular fractures in paediatric patients. In this respect the age limit between the adult and child should probably be lowered significantly.
KEY WORDS: Children - MaxiUofacial injuries - Mandibular fractures
INTRODUCTION
both mandibular and midfacial fractures. Although problems related to the lower and middle third fractures are different, there are only a few detailed analyses exclusively concerning mandibular fractures. We chose to study mandibular fractures exclusively in order to analyze the role of the growing mandible and the dental development on the fracture pattern.
Most facial trauma occurs in young adults (Lamberg, 1978; Bochlogyros, 1985; Ellis et al., 1985; Haymond et al., 1988; Cook and Rowe, 1990). However, maxillofacial fractures in children are rare. In Rowe's analysis of 1500 fractures, less than 5% of the fractures were in children younger than 12 years of age (Rowe, 1968). A low incidence has been presented in other studies too, (Hagan and Huelke, 1961; Oikarinen and Malmstr6m, 1969; Lamberg, 1978; Khan, 1988; Sawhney and Ahuja, 1988; Kotilainen et al., 1990; Zachariades et al., 1990). The low incidence has been explained by certain characteristics of the child: in infants and younger children the face is smaller in proportion to the head size and the prominent frontal cranium shields the facial skeleton, thus protecting it from trauma. In McGraw and Cole's (1990) study, the fractures shifted from the upper to the lower region of the face with increasing age; mandibular fractures were more prevalent in the older age groups and frontal and orbital fractures occurred more frequently in the youngest age group (McGraw and Cole, 1990). Small paranasal sinuses and great elasticity of the bone are also characteristic of young children and provide resistance to fracturing. 75-90% of jaw fractures in children occur in the mandible (Andersson et al., 1989; Zachariades et al., 1990; Stylogianni et al., 1991). Studies concerning paediatric maxillofacial trauma have usually included
PATIENTS AND METHODS The present study included 157 patients under 16 years of age, with mandibular fractures treated in the Department of Oral and Maxillofacial Surgery, Helsinki University Central Hospital, Finland, during the 10-year period 1980-1989. The patient records and all available documents and X-rays were reviewed. The data included age at the time of injury, mechanism of injury, anatomical site of fracture, associated injuries and treatment methods. In addition, the fracture lines available from panoramic images (orthopantomographs) were drawn on separate figures to illustrate the patterns of mandibular injuries. In cases in which radiographs were not available (35) the fracture lines were drawn according to the X-ray protocols made by a radiologist. The patients were divided into four age groups (group A: 0-5 years, group B: 6-9 years, group C:10-12 years and group D:13-15 years) according to 292
Mandibular fractures in children
the development of the dentition. In general, the age range of group A is regarded as the period of the decidous dentition, that of group B as the first eruption period, that of group C as the second eruption period and the age range of group D as the stage of the permanent dentition (Hurme, 1945; Haavikko, 1970). Similarities and differences in the cause and type of injuries were compared in relation to these age groups.
RESULTS Of the total of 157 children 107 were boys and 50 girls with a mean age of 8.4 years (range 1 through 15 years). The age and sex distribution are given in Figure 1. More than one third of the patients belonged to the oldest age group (37.6 %) and only 19 children were younger than 6 years of age (12.1%). Groups B and C (6-9 and 10-12 years) were about the same size, 24.2 % and 26.1%, respectively. There was an overall 2: l boy-girl ratio and a male preponderance in all age groups (Fig. 1).
related. All patients with mandibular fractures caused by motor-bike accidents and 85.7 % of the patients with fractures caused by violence were boys. Table 2
[
Group A
Group B
Group C
Group D
10 11 '~2
13 14 15
¢n E o o
10
0 1
2
3
4
5
6
7
8
9
age (years) •
Yearly and monthly distribution of accidents
Boys
Gids
E~
Fig, l Age and sex distribution of 157 children with 220 mandibular fractures.
The yearly number of children with mandibular fractures in our sample from the Helsinki area ranged from 9 (5.7% of the total) in 1984 to 25 (15.9% of the total) in 1982. The incidence of accidents correlated significantly with the time of the year: more than half of all accidents occurred during the period MaySeptember (66.9 %) (Fig. 2). _=
Causes of injury The causes of the mandibular fractures are shown in Table 1. The most common mechanism of injury was a road traffic accident (RTA) (57.3 %). The majority of the RTA's were connected with cycling; 61 patients, 38.9 % of the whole material, suffered their injury this way. This was the most frequent aetiological factor in all age groups. Motorbike, car, and car-pedestrian accidents accounted for 18.4% of the injuries. Falls, 17.8 %, were nearly as common an aetiological factor and 10.8 % of the cases were connected with sports activities such as horse-back riding, skiing, contact sports, or ball-games. Violence was the cause of fractures in 14 cases (8.9 %). In age groups A and B (the under ten's) RTA's and falls were the two main causes of the fractures (for all children in group A and in 94.7 % of the cases in group B). In groups C and D the aetiology of the trauma was more variable. In these age groups only 63 % of the children had fractures that were caused by RTA or falls. Cycling as an aetiological factor decreased from 52.6 % in group A to 23.7 % in group D. Of the total of 11 motorbike accidents, 10 (90.9 %) occurred in age groups C and D. All the sports-related injuries and 92.8 % of the violence-associated trauma occurred in children over 10 years of age. The distribution of the causes of the injuries were sex-
293
20
i
"6
o_ 10
0
i
i
JAN ~ MIR A;R M~Y J~ JOL ~
~
d~ ~
month
Fig. 2 - Monthly distribution of accidents.
Table 1 - Causes of 220 mandibular fractures in 157 children
Type of accident
No. of patients
%
Road traffic accidents car bicycle motorbike auto-pedestrian Fall Sports Violence Hit by object Gunshot Total
90 9 61 l1 9 28 17 14 7 1 157
57.3 5.7 38.9 7.0 5.7 17.8 10.8 8.9 4.5 0.6 100
294
Journal of Cranio-Maxillo-Facial Surgery
Table 2 - Comparison of clinical features related to paediatric mandibular fractures in relation to the four age groups (in %) Group A Group B Group C Group D Aetiology bicycle fall sports violence motorbike car car-pedestrian bit by object gunshot Total Type of fracture condylar symphysis angle body alveolar ramus Total Midfacial fractures Treatment observation operative
52.6 36.8 0 0 0 5.3 5.3 0 0 100
52.6 23.7 0 2.6 2.6 7.9 7.9 2.6 0 100
41.5 17.1 19.5 0 4.9 7.3 0 7.3 2.4 100
23,7 8,5 15,3 22,0 13.6 3.4 8.5 5.1 0 100
76.0 8.0 4.0 0 12.0 0 100 0
63.6 18.2 3.6 9.1 5.4 0 100 7.9
63.8 12.1 8.6 10.3 3.4 1.7 100 9.8
50.0 15.5 17.1 11.0 2.4 3.7 100 15.2
84.2 10.5
55.3 10.5
53.7 9,8
35.6 18.6
shows the distribution of aetiological factors for each age group.
Injuries A total of 220 mandibular fractures were diagnosed in the 157 patients. A majority of the fractures (60%)
occurred in the condyler region. The next common fracture site (14.5 %) was the mandibular symphysis, defined as the region between the canines, followed by the angle (10%) and body regions (9.1%). Four (1.8 %) fractures were found in the mandibular ramus. 104 patients (66.2%) had only 1 fracture, 42 (26.7 %) had 2 and 11 (7 %) had 3 or more fractures in the mandible. Condylar fractures were diagnosed in 113 (72%) patients. Of these 94 had a unilateral condylar fracture (83.2%) and 19 (16.8%) suffered from bilateral fractures. In 27 patients (17.2%) the condylar fractures were associated with fractures of other regions (mostly the symphysis region). 10 patients had dentoalveolar fractures. Seven (4.5%) had dentoalveolar fractures only and in 3 cases mandibular fractures of other regions were also diagnosed. Of all injuries, condylar fractures were the most common in all age groups (76 % in group A, 63.6 % in group B, 63.8 % in group C, and 50 % in group D). However, the relative frequency of condylar fractures decreased and those of the body, angle, and ramus increased with increasing age. Fractures in the body, angle, and ramus regions occurred less frequently in patient groups under 10 years of age as compared with the older age groups (Figs 3 and 4). Body fractures constituted 10.3 % of the fractures in group C and 11% in group D but in only 6.2 % of all fractures in groups A and B. There were no significant differences in the frequency distribution of symphysis fractures between age groups A + B , C and D (Table 2). Associated fractures in the midface were diagnosed in
Fig. 3 - The mandibular fracture lines in children in groups A and B (under l0 years) drawn from orthopantomographs.
Fig. 4
The mandibular fracture lines in children in groups C and D (10-15 years) drawn from orthopantomographs.
Mandibular fractures in children Table 3
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Maxillofacial fractures in children; a review of the literature
Reference
Age limit (years)
Total material (patient no.)
Children (%)
Anatomical area studied
Study period
Rowe 1968 Oikarinen and M a l m s t r 6 m 1969 Bochlogyros 1985 K h a n 1988 H a g a n and Hulke 1961 Ellis et al. 1985 Rowe 1968 Zachariades et al. 1990 Lamberg 1978 Lamberg 1978 Sawhney and Ahuja 1988 Kotilainen et al. 1990 Present study
< < < < < < < < < < < < <
1500 1284 853 311 319 2137 1500 3908 704 475 262 350 2050
0.9 3.7 6.1 1.3 6.3 1.8 4.9 5.2 5 4 9.2 5.7 7.7
facial bones facial bones mandible facial bones mandible mandible facial bones facial bones mandible midface facial bones facial bones mandible
1948-1966 1958 1967 1960 1980 1985-1986 1948-1958 1974~1983 1948-I966 1960-1984 1969-1975 1969-1975 1982-1983 1980-1984 1980-1989
6 10 10 10 11 i1 12 15 16 16 16 16 16
13 patients and these were most frequently observed in group D (8 patients) (Table 2). Nearly all of these patients were males (84.6 %). Three patients had an additional skull fracture. Cerebral injuries such as commotio cerebri or contusion were diagnosed in 17 patients, fractures of the upper and/or lower extremities in 11, a hip fracture in 2, and a pneumothorax in 1 patient. Treatment
In half of the patients (51.6%), treatment of the mandibular fractures was confined to observation only. Rigid IMF was used in 61 cases and the duration of IMF was 21 days on average (range ~ 3 5 days). Three patients were treated by the use of elastic IMF alone. In 15 patients, arch bars for IMF were applied under general anaesthesia or sedation because of poor cooperation. Of the patients in group A, 84.2 % were treated by observation and soft diet alone, the corresponding figure being 55.3 % for group B, 53.7 % for group C and 35.6% for group D. 21 patients (13.4%) underwent open reduction and osteosynthesis. The fixation of fractures was performed using transosseous wiring in 17 and miniplates in 3 cases. In all patients treated by transosseous wiring or miniplates, IMF was used postoperatively for 24 weeks. In only 1 patient (a 12-year-old boy), a fracture of the symphysis region was stabilized with an AO rigid plate (Table 2). DISCUSSION The Department of Oral and Maxillofacial Surgery, Helsinki University Central Hospital, Finland, is the only unit in the Helsinki area which treats mandibular fractures, and serves a population of about 1.5 million. The present material can be considered to cover the mandibular fractures needing either consultation or active therapy that occurred in this area between 1980-1989. There are numerous reports on maxillofacial trauma in children. (Rowe, 1968; Amaratunga, 1988; Harrington et al., 1988; Uji and Teramoto, 1988; Andersson et al., 1989; Kotilainen et al., 1990; McGraw and Cole, 1990; Zachariades et al., 1990; Stylogianni
et al., 1991). In general, maxillofacial fractures seem to occur infrequently in paediatric patients (Table 3). The proportion of children younger than 6 years is approximately 1% of all patients with mandibular fractures (Hagan and Huelke, 1961 ; Rowe, 1968), and only 2-6% of fractures occur before the age of 10 (Hagan and Huelke, 1961 ; Oikarinen and Mahnstr6m, 1969; Bochlogyros, 1985). The incidence found in the present survey, 7.7% in children younger than 16 years and 2.9 % in children younger than 10 years, are close to those previously reported. The variation in the incidence and age distribution might be related to the socio-economic status of the different countries concerned. In Finland, the percentage of children with mandibular fractures has increased slightly over the past two decades (Lamberg, 1978). This may be attributable to the change in the age structure and an increase in the population in the Helsinki area. The results of this study showed that falls and bicycle accidents were the two main causes of mandibular fractures in the under 10 years age groups, but clear aetiological variations were observable in the older patient groups. This is probably caused by the fact that the lifestyle of children changes when they reach the second decade. An important finding of this study is the predominance of bicycle accidents (38.9 %) especially in the youngest age group (52.6 %). This result suggests that with respect to children cycling, more attention should be paid to protective and preventive measures. All cyclists should always wear safety helmets that cover the chin so that the condylar processes are protected (Lindqvist et al., 1986). Parents should be made aware of the hazards of cycling; young children are not able to cope with traffic, and some of the accidents on playing grounds might be avoided with more caution. Violence is the main aetiology of maxillofacial fractures in adults. The results of this study showed that children of 1315 years are already prone to receive mandibular fractures when assaulted. The prevention of violence through education in schools is therefore of major importance, in order to decrease the incidence of facial injuries in youngsters. A clear predominance of condylar fractures was found in all four age groups. However, the characteristics of the fracture location also reflected some
296
Journal of Cranio-Maxillo-Facial Surgery
differences between the age groups; most cases of mandibular body and angle fractures were diagnosed in patients over 10 years of age, and condylar fractures had a decreasing incidence with age. It seems that the fracture location in children over 10 years of age gradually assumes a pattern similar to that in adults. Treatment of mandibular fractures in children is usually conservative and is often restricted to intermaxillary fixation only. (Amaratunga, 1987; Crockett et al., 1989; Jamerson and White, 1990). The indications for surgical treatment are limited. One reason is the growing mandible which might be disturbed by open surgery and osteosynthesis, Another reason is the lack of space for osteosynthesis material due to the presence of developing tooth follicles in the mixed dentition. An additional explanation is that the majority of the fractures (60%) in this age group, and especially in patients under 10 years of age, were condylar fractures which are usually treated conservatively. In studies concerning maxillofacial trauma in children, the upper age limit varies from 11-20 years (Amaratunga, 1988; Uji and Teramoto, 1988; Andersson et al., 1989; Kotilainen et al., 1990; McGraw and Cole, 1990; Zachariades et al., 1990; Stylogianni et al., 1991). The criteria for defining the age groups are often unclear. According to the results of this study, a decisive limit seems to be 10 years of age. After this age the aetiologies and fracture types become similar to those in young adults. The differences between the first and second decade should be taken into consideration in studies concerning diagnosis and treatment of mandibular fractures in paediatric patients.
References Andersson, L., M. Hultin, O. Kjellman, A. Nordenram, G. Ramstrdm: Jaw fractures in the county of Stockholm (1978-1980). Swed. Dent. J. 13 (1989) 201 Amaratunga, N. A. de S: The relation of age to the immobilization period required for healing of mandibular fractures. J. Oral Maxillofac. Surg. 45 (1987) 111 Amaratunga, de S. N. A.." Mandibular fractures in children. A study of clinical aspects, treatment needs, and complications. J. Oral Maxillofac. Surg. 46 (1988) 637 Bochlogyros, P. N. : A retrospective study of 1521 mandibular fractures. J. Oral Maxillofac. Surg. 43 (1985) 597 Cook, H. E., M. Rowe: A retrospective study of 356 midfacial
fractures occurring in 225 patients. J. Oral Maxillofac. Surg. 48 (1990) 574 Crockett, D. M., R. P. Mungo, R. E. Thompson: Maxillofaciai trauma. Pediatr. Clin. North Am. 36 (1989) 1471 Ellis, E., K. F, Moos, A. El-Attar: Ten years of mandibular fractures: An analysis of 2137 cases. Oral Surg. 59 (1985) 120 Haavikko, K. : The formation and the alveolar and clinical eruption of the permanent teeth. An orthopantomographic study. Proc. Finn. Dent. Soc. 66 (1970) 103 Hagan, E. H., D. F. Huelke: An analysis of 319 case reports of mandibular fractures. J. Oral Surg. 19 (1961) 93 Harrington, M. S., A. B. Eberhart, J. F. Knapp : Dentofacial trauma in children. ASDC J. Dent. Child. 55 (1988) 334 Haymond, C., C. Nicholson, H. A. Kiyak, D. Trimble : Age differences in responses to facial trauma. Spec. Care Dentist 8 (1988) 115 Hurme, V. 0.: Ranges of normalcy in the eruption of permanent teeth. ASDC J. Dent. Child. 16 (1949) 11 Jamerson, R. E., J. A. White: Management of pediatric mandibular fractures. J. LA State Med. Soc. 142 (1990) 11 Khan, A, A. : A retrospective study of injuries to the maxillofacial skeleton in Harare, Zimbabwe. Br. J. Oral Maxillofac. Surg. 26 (1988) 435 Kotilainen, R., J. Kiirj& A. Kullaa-Mikkonen : Jaw fractures in children. Int. J. Pediatr. Otorhinolaryngol. 19 (1990) 57 Lamberg, M. : Maxillofacial fractures. An epidemiological and clinical study on hospitalized patients. Proc. Finn. Dent. Soc. 74 Suppl. VII (1978) Lindqvist, C., S. Sorsa, T. Hyrkiis, S. Santavirta: Maxillofacial fractures sustained in bicycle accidents. Int. J. Oral Maxillofac. Surg. 15 (1986) 12 McGraw, B. L., R. R. Cole: Pediatric maxillofacial trauma. Arch. Otc,laryngol. Head Neck Surg. 116 (1990) 41 Oikarinen, V., M. Malmstr6m: Jaw fractures. Proc. Finn. Dent. Soc. 65 (1969) 95 Rowe, N. L. : Fractures of the facial skeleton in children. J. Oral Surg. 26 (1968) 505 Sawhney, C. 0., R. B. Ahuja: Faciomaxillary fractures in north India, A statistical analysis and review of management. Br. J. Oral Maxillofac. Surg. 26 (1988) 430 Stylogianni, L., A. Arsenopoulos, A. Patrikiou : Fractures of the facial skeleton in children. Br. J. Oral Maxillofac. Surg. 29 (1991) 9 Uji, T., T. Teramoto: Occurrence of traumatic injuries in the oromaxillary region of children in a Japanese prefecture. Endod. Dent. Traumatol. 4 (1988) 63 Zachariades, N., D. Papavassiliou, F. Koumoura : Fractures of the facial skeleton in children. J. Cranio-Max.-Fac. Surg. 18 (1990) 151
Hanna Thor6n, DDS Department of Oral and Maxillofacial Surgery IV Department of Surgery Helsinki University Central Hospital Kasarmink. 11-13 SF-00130 Helsinki 13, Finland Paper received: 11 January 1992 Accepted: 31 March 1992