4th December 2015, Volume 128 Number 1426

Blake K Moore, Ryan B Smit, Angus N Colquhoun, W Murray Thomson

Maxillofacial injury continues to place a burden on the New Zealand hospital sector. Road traffic accidents (RTA) and interpersonal violence (IPV) have been highlighted as the most common causes.1-3 Maxillofacial fractures are often associated with a significant social cost and personal morbidity.2

For some time in New Zealand, RTA-related maxillofacial trauma has reduced and, in some areas, has been less common than falls and sporting injuries.1,4,5 This is mainly due to changes in transport policy, including revised drink-driving laws, reduced road speed, modern vehicle safety measures (such as the wider availability of airbags), and improved road conditions.5

IPV continues to be the leading cause of maxillofacial injury in New Zealand,1-4,6 primarily involving young men and with alcohol as a frequent contributor.1,2,7,8 Reports from the Canterbury, Otago, and Waikato regions showed that IPV accounted for between 32% and 44% of all facial fractures.1,3,4 Anecdotal reports from the Waikato region suggest that RTA have continued to decrease, while a greater proportion of facial fractures are due to IPV. A previous analysis of facial fractures in the Waikato region found that IPV-related injury steadily increased from 31% to 41% in the first 9 years of their observation period.1

International research in Western countries (such as the UK, France and Finland) also supports a downward trend in RTA-related fractures, with IPV now being the leading cause.9,10 In Denmark, the incidence of IPV-related fractures doubled during the 1960–1987 period.11 However, road traffic accidents remain the leading cause of facial fractures in developing countries such as Brazil,12,13 India and Iran,14,15 and also in some developed nations, such as Japan, Greece, and the Netherlands.16-18

The multifactorial nature of facial fractures means that both their incidence and aetiology vary not only among countries,19 but also within them. The aim of this study was to describe the characteristics, nature and treatment of maxillofacial fractures presenting to a tertiary referral centre in New Zealand during a 10-year period, and to determine whether trends observed in an earlier such analysis have continued.


The Department of Maxillofacial and Oral Surgery at Waikato Hospital provides a tertiary service to a regional population of over 846,600 in the upper central North Island. The catchment areas of service include the regions of Waikato, Taupo, Gisborne, Bay of Plenty, the Coromandel Peninsula and Thames.

Clinical data collected from all patients with maxillofacial fractures attending the Department of Maxillofacial and Oral Surgery at Waikato Hospital from January, 2004, to December, 2013, were retrospectively analysed using information that had been recorded prospectively using a paradox database. Patients who had sustained facial fractures were included, but those with isolated soft tissue injuries were omitted. Details recorded included sex, age, cause of injury, classification of injury, date of injury, and the treatment provided. Regrettably, information on ethnicity and alcohol involvement was not collected in the database. Statistical analysis was undertaken using SPSS (Statistical Package for the Social Sciences; SPSS Inc, Chicago, Illinois, US; version 20). As far as possible, the analytical and reporting approaches were kept similar to those used in an earlier analysis of a case series of Waikato maxillofacial fractures, in order to enable direct comparisons to be made.1

Following the computation of descriptive statistics, bivariate associations were tested for statistical significance using the Chi-squared test. Census numbers for 1991, 1996, 2001, 2006 and 2013 were used as estimates for the number of people at risk in each of these years for the Waikato DHB catchment population. A linear regression model was fitted to give an estimated population for each of the years from 1991 to 2013 for that catchment. This enabled rates to be calculated and compared to those reported by Buchanan et al (2005)1 by estimating the population at risk. We used STATA (StataCorp LP, Texas, US) to calculate the rate ratios and their exact 95% confidence intervals.


Table 1 lists fracture demographic characteristics and aetiological data. A total of 1,975 patients presented with maxillofacial fractures. The male-to-female ratio observed was approximately 4:1. Those in the 20–29-year-old age group commonly presented with facial fractures (38.4% of all cases). IPV was the most common fracture aetiology (54.5%), followed by RTA (14.5%), and sport (11.9%). Falls were the most common cause in the oldest female age group (50+ years), while IPV was the most common among all other ages.

Table 1: Number of maxillofacial fracture cases for the periods 2004–06, 2007–09 and 2010–13, by sociodemographic characteristics and fracture aetiology (brackets contain column percentages unless otherwise indicated) 









467 (84.3)

424 (82.2)

714 (79.1)

1,605 (81.3)


87 (15.7)

92 (17.8)

189 (20.9)

368 (18.7)

Age group (years)


147 (26.5)

142 (27.6)

222 (24.6)

511 (25.9)


240 (43.3)

193 (37.5)

323 (35.8)

756 (38.4)


72 (13.0)

73 (14.2)

128 (14.2)

273 (13.9)


49 (8.8)

52 (10.1)

112 (12.4)

213 (10.8)


46 (8.3)

54 (10.5)

118 (13.1)

218 (11.1)


254 (45.8)

198 (38.5)

336 (37.2)

788 (40.0)



296 (53.4)

293 (56.6)

487 (53.9)

1,076 (54.5)


96 (17.3)

69 (13.3)

121 (13.4)

286 (14.5)


49 (8.8)

58 (11.2)

123 (13.6)

230 (11.6)


73 (13.2)

65 (12.5)

97 (10.7)

235 (11.9)


39 (7.0)

30 (5.8)

62 (6.9)

131 (6.6)


1 (0.2)

3 (0.6)

13 (1.4)

17 (0.9)

All combinede

554 (28.1)

518 (26.2)

903 (45.7)

1,975 (100.0)

aAge data missing for 4 patients; bSex data missing for 2 patients; cInterpersonal violence; dRoad traffic accident; eRow percent 

Table 2 shows that the rate of facial fractures increased from 38.8 per 100,000 person-years at risk to 45.5 per 100,000 person-years at risk. Rates for IPV increased over time from 20.7 per 100,000 person-years at risk (95% CI = 18.5–23.2) to 24.5 per 100,000 person-years at risk (95% CI = 22.4–26.8). Facial fractures due to RTA, sport and falls remained similar.

Table 2: Rates of fractures by period and aetiology quantified per 100,000 person-years at risk (brackets contain 95% confidence intervals) 








20.7 (CI 18.5–23.2)

20.1 (CI 17.3–22.6)

24.5 (CI 22.4–26.8)


6.7 (CI 5.5–8.2)

4.7 (CI 3.7–6.0)

6.1 (CI 5.1–7.3)


3.4 (CI 2.6–4.5)

4.0 (CI 3.1–5.2)

6.2 (CI 5.2–7.4)


5.1 (CI 4.1–6.4)

4.5 (CI 3.5–5.7)

4.9 (CI 4.0–6.0)


38.8 (CI 35.7–42.1)

35.6 (CI 32.6–38.7)

45.5 (CI 42.6–48.5)

Number of cases




 Table 3 shows the percentage of primary reported cause by gender. Males accounted for 77.2% of RTA-related fractures and 87.2% of all fractures related to IPV and sport. The highest prevalence for primary reported cause in females was falls (39.6%).

Table 3: Percentage of primary reported cause by gender



Male (%)

Female (%)
















A total of 2,258 fractures were recorded among the 1,975 individuals (Table 4). Mandibular fractures were the most common, with 996 individuals presenting. Most of these were at a single site (54.5%). The zygomatic complex was the next most common fracture (463) followed by orbital fractures (449). The rate of orbital fractures rose from 8.4 to 11.6 per 100,000 person-years at risk. Other fracture types were less common. Most patients (87%) presented with only one type of fracture; 8.8% had two types of fracture (such as of the orbital floor and zygoma); and 4.2% presented with three.

Table 4: Type of maxillofacial fracture cases, by fracture aetiology and treatment (brackets contain column percentages unless otherwise indicated) 

Type of maxillofacial fracturea



Le Fort I






Row totals



614 (61.7)

51 (35.9)

208 (46.3)

230 (49.7)

7 (21.2)

12 (29.3)

58 (43.3)

1,180 (52.3)


110 (11.0)

50 (35.2)

93 (20.7)

88 (19.0)

15 (45.5)

4 (9.7)

29 (21.6)

389 (17.2)


86 (8.6)

23 (16.2)

66 (14.7)

59 (12.7)

2 (6.1)

12 (29.3)

17 (12.7)

265 (11.7)


129 (13.0)

7 (4.9)

41 (9.1)

55 (11.9)

5 (15.1)

4 (9.7)

13 (9.7)

254 (11.3)


48 (4.8)

9 (6.4)

37 (8.3)

29 (6.3)

4 (12.1)

9 (22.0)

16 (11.9)

152 (6.7)


9 (0.9)

2 (1.4)

4 (0.9)

2 (0.4)

0 (0.0)

0 (0.0)

1 (0.8)

18 (0.8)

Total for fracture typed

996 (44.1)

142 (6.3)

449 (19.9)

463 (20.5)

33 (1.5)

41 (1.8)

134  (5.9)

2,258 (100.0)



245 (24.6)

51 (36.4)

212 (47.2)

186 (40.4)

9 (27.3)

31 (75.6)

68 (50.7)

802 (35.6)

Surgical fixation

736 (74.0)

82 (58.6)

223 (49.7)

218 (47.4)

22 (66.7)

5 (12.2)

54 (40.3)

1,340 (59.5)


14 (1.4)

7 (5.0)

14 (3.1)

56 (12.2)

2 (6.1)

5 (12.2)

12 (9.0)

110 (4.9)

 a6 patients had missing treatment data; totals do not sum to 1975 because some individuals experienced more than one type of injury; bInterpersonal violence; cRoad traffic accident; dRow percent

Table 5 presents data on how cases were treated over the study period. Over half (58.2%) of all facial fractures were surgically fixated and over one-third (36.8%) were treated conservatively. The number of cases requiring surgical fixation increased from 2004–2006 to 2007–2009 (p<0.001) but no overall trend was observed.

Table 5: Number of cases by reported primary cause, number of cases by fracture type, and number of cases by treatment type over the study period (percentages indicated in brackets unless otherwise indicated) 

Primary Cause






296 (53.5)

293 (56.6)

487 (53.9)


96 (17.3)

69 (13.3)

121 (13.5)


49 (8.8)

58 (11.2)

123 (13.6)


73 (13.2)

65 (12.5)

97 (10.7)


1 (0.2)

3 (0.6)

13 (1.4)


39 (7.0)

30 (5.8)

62 (6.9)

Fracture Type


252 (39.4)

290 (49.1)

451 (43.9)


32 (5.0)

38 (6.4)

65 (6.3)


120 (18.8)

98 (16.6)

230 (22.4)


166 (26.0)

111 (18.8)

196 (19.1)


14 (2.2)

6 (1.0)

22 (2.1)


55 (8.6)

48 (8.1)

64 (6.2)

Treatment Type


293 (52.9)

344 (67.5)

507 (56.1)


232 (41.9)

139 (27.3)

353 (39.1)


29 (5.2)

27 (5.2)

43 (4.8)


This study was a retrospective clinical audit of patients who presented, over a 10-year period, with facial fractures to a tertiary trauma hospital Oral and Maxillofacial Surgery (OMS) unit. Fractures were most common in young men.

We observed an increase in the rate of IPV-related fractures, orbital fractures, fractures due to falls, and the total rate of facial fractures. The rate of RTA-related cases fell slightly, while sports-related fractures were similar.

Missing age, sex, and treatment data were noted as part of imperfect data entry into the database. Fortunately, these were low in number and unlikely to have affected the findings. Having missing data remains a risk with such analyses of routinely-collected data: treating clinicians have many responsibilities and distractions, and these are likely to compromise data entry on occasion. Another limitation of this study was that information on ethnicity, or alcohol consumption prior to injury, was not available. The original purpose of the database was to provide hospital management with an indication of the departmental workload. Despite this, sporadic data were collected on ethnicity and alcohol, but this information was not of sufficient quality to be included in this analysis. However, many previous studies have reported alcohol consumption to be a strong contributing factor to facial fractures caused by IPV and RTA, especially in the 15–39 age group.1,4,5,7,8 Previously, Māori have been found to be over-represented in facial fracture presentations at this particular tertiary hospital.1 There is no reason to suspect that any change in pattern has occurred since the earlier study.

Important trends were identified and can be directly compared with findings from the previous study at this unit.1 Although the Department of Maxillofacial and Oral Surgery at Waikato Hospital services a substantial and diverse population catchment, the findings cannot be generalised to all of New Zealand. Males aged 20–39 most frequently presented with facial fractures; this is a pattern which has been observed previously at this OMS unit and others around New Zealand.1,2,4,5,7 The rate of IPV-related maxillofacial trauma also increased at this tertiary centre, up from 12.7 (CI 11.9–13.5) per 100,000 person-years at risk in 1989–2000 to 24.5 (CI 22.4–26.8) by 2004–2013. Currently, it is almost twice the rate of the 1989–2000 period (p<0.0001) and this is of significant concern.1

The decrease in the number of RTA-related fractures observed is in keeping with observations from other OMS units around New Zealand.1,2,5,6 Interestingly, despite this, we did not observe an overall decrease in high-velocity injury fracture patterns, such as Le Fort fractures, because there was an increase in Le Fort 1 fractures caused by IPV. Although facial fracture rates due to falls were similar to the previous study, they continued to be common in the female 50+ age group.1,20 It is clear that falls continue to be a significant cause of maxillofacial trauma in older adults, and this is likely to grow as New Zealand’s older-adult population increases.

Unexpectedly, the rate of orbital fractures observed was 5.1 times higher (p<0.0001) than that seen in the previous study at this unit.1 This was due to a large rise in orbital fractures caused by IPV, RTA, and falls since the 1989–2000 period.1 Similar proportions of orbital fracture cases have been reported in other New Zealand studies.3,4 The increase in the orbital fracture rate is likely due to increased detection and referral from secondary centres.

Initially, the proportion of cases conservatively managed was similar to figures reported by other units, but it decreased towards the end of the study period.4,5,7,8 The proportion of cases requiring surgery in New Zealand does vary due to differences in the local populations and in the available service-mix. The proportion of fractures requiring internal fixation did increase from previously (about 60%, up from 49%) and is higher than that seen in another New Zealand hospital during a similar period.1,4 This probably has a multifactorial origin, reflecting an increase in proportion of displaced fractures, changes in surgical staff, and a rise in serious interpersonal violence in the Waikato region. Facial fractures due to interpersonal violence have continued to rise, while those caused by road traffic accidents have continued to decline. However, the ever-increasing number of facial fractures places pressure on staffing levels, ward beds, theatre availability, and hospital funding. It is apparent that the level of interpersonal violence has worsened since the previous study, and remains an important public health issue in the Waikato region. Programmes such as the Violence Intervention Programme (VIP) and ‘It’s not OK’, which have been running across New Zealand during the study period, appear to have had no impact on reducing IPV-related maxillofacial fractures in the Waikato region.21 With such a clear impact on current and future hospital resources and staffing, public health intervention is required. This should target contributory factors, such as alcohol consumption and drug use, but also the main culprits, namely young males.

Further studies are needed to investigate the role of alcohol and drugs (especially methamphetamine) in this population presenting with facial fractures.


The rate of IPV related maxillofacial fractures presenting to this tertiary centre has continued to increase throughout the study period and is now at almost double the rate since the 1998-2000 period. It continues to be the dominant cause of injury, while RTA-related fractures are decreasing. The ever-increasing rate of facial fractures presenting to Waikato Hospital places significant demands on scarce clinical resources, such as operating theatre time and staffing numbers. An increase in theatre access for maxillofacial doctors and additional staff in oral and maxillofacial surgery departments is essential to deal adequately with this problem. IPV is an escalating cause of facial fractures that requires urgent and interventional public health prevention strategies.


The rate of facial fractures presenting to Waikato Hospital has been increasing since 1989. In addition the rate of violence-related facial fractures is now at almost double the rate seen in 1998-2000. It continues to be the dominant cause of injury, while road traffic accident related fractures are decreasing. This continual increase in fractures presenting to Waikato Hospital places significant demands on scarce clinical resources, such as operating theatre time and staffing numbers. Violence is an escalating cause of facial fractures that requires urgent and interventional public health prevention strategies.


Injury to the maxillofacial region continues to place a burden on hospital care in New Zealand, with maxillofacial fractures often being associated with both a significant social cost and personal morbidity. This article describes the characteristics, aetiology and treatment patterns in a tertiary maxillofacial centre in New Zealand during a 10-year period. Over the observation period, a total of 1,975 cases were treated, with a male-to-female ratio of 4:1. The highest incidence was in the 20–29-year-age group. Interpersonal violence (IPV) was the most common aetiology, observed in 54.5% overall, and more common among males than females (58% and 38% respectively; P<0.001). Falls were the most common cause of injury among older females (those aged 50+). Comparison to an earlier analysis shows that IPV-related maxillofacial trauma has increased significantly at this tertiary centre, increasing from 36.2% of cases in 1989–2000, to 54.5% in 2004–2013. There remains an urgent need for appropriate health promotion to reduce interpersonal violence, as well as an increase in the staffing numbers of maxillofacial units in New Zealand.

Author Information

Blake Moore, 5th-year medical student, University of Otago, Wellington School of Medicine, Wellington, New Zealand; Ryan Smit, 5th year medical student, University of Otago, Wellington School of Medicine, Wellington, New Zealand; Angus Colquhoun, Consultant Oral and Maxillofacial Surgeon, Department of Maxillofacial and Oral Surgery, Waikato Hospital, New Zealand; W. Murray Thomson, Professor of Dental Epidemiology and Public Health, Department of Oral Sciences, University of Otago Faculty of Dentistry, Dunedin, New Zealand.


The authors thank Mr Steve Evans, Mr Brian Whitley and Mr Simon Lou, Consultant Oral and Maxillofacial Surgeons, Waikato Hospital, who contributed to the surgical treatment of the patients, and Dr Dalice Sim, University of Otago, Wellington School of Medicine, for assisting with the statistical analysis of data.


Blake Moore, 5th year medical student, University of Otago, Wellington School of Medicine, Wellington, New Zealand

Correspondence Email


Competing Interests



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