Orthognathic surgery for the Asian patient and the influence of the surgeon’s background on treatment

Abstract

The aim of this study was to determine whether there are differences in esthetic preferences and orthognathic treatment for Asian patients between US- and Asian-trained surgeons. Twenty-five Caucasian-American, 23 Asian-American, 24 Asian oral and maxillofacial surgeons (OMFS) completed an Institutional Review Board (IRB)-approved survey. They were asked to rate seven Asian male and female profiles from most attractive to least attractive and to choose maxillary advancement, mandibular setback, or no treatment for an Asian male and female patient with a maxillomandibular discrepancy. There was no statistical difference for the most and least attractive rankings among the OMFS. Variations in ranking for intermediate profiles showed a statistical difference between the Asian- and US-trained OMFS. These intermediate profile rankings appeared to explain the differences in surgical treatment. Treatment recommendations for the Asian male among the OMFS, regardless of ethnicity, preferred maxillary advancement. For the Asian female, all Asian-trained OMFS preferred mandibular setback, while nearly 40% of US-trained OMFS preferred maxillary advancement ( p = 0.003). Differences in surgical management of the Asian patient were dependent on whether the surgeon trained in the US or in Asia and the gender of the patient. There was concordance between the Asian-American and Caucasian-American surgeons.

Oral and maxillofacial surgeons (OMFS) have incorporated cephalometric measurements as a guideline to help diagnose and treat patients for orthognathic surgery. The most common cephalometric analyses used in the USA are of Caucasian norms and are based on population studies of young Caucasians, typically of Scandinavian descent (i.e. Bjork analysis, Steiner & Tweed analysis) . The shortcomings of generalizing one group of standard measurements to all ethnic groups have spawned interest in devising ethnic specific approaches and modifications when evaluating facial esthetics and treating dentofacial deformities. In the last 40 years, many studies have examined the normal cephalometric measurements specific to a particular ethnicity, including Koreans , Chinese , Japanese , Filipinos , Brazilians , and African-Americans . This is timely as the population of the USA is becoming increasingly ethnically diverse.

Facial reconstructive surgeons encounter facial differences or variations among ethnic and racial groups that are not well defined. The normal Asian facial profile is often described as flat or straight with upper and lower lip fullness . A series of studies in the orthodontic literature demonstrated similarities in preference of an esthetic Asian profile between Chinese health professionals (orthodontists and oral surgeons) and Chinese lay people ; between Chinese and white Australian orthodontists and white Australian lay people ; and among other Asian lay people including Malays, Chinese, and Indians . Despite the similarities, there are different opinions between patients and care providers. For example, patients may not feel that a variant profile is enough to warrant surgery while surgeons may recommend surgery more often . While there is agreement as to what is most and least esthetic in terms of Asian appearance, there may not be agreement on the appropriate treatment procedure and the surgical esthetic outcome. This difference in treatment and alteration of facial features may be more critical among Asian patients in whom the soft tissue changes are not as predictable as those studied in Caucasian patients . Surgeons from different ethnic backgrounds may recommend different treatment plans for the same dentofacial deformity and change the appearance of the Asian patient to appear more full or more flat and possibly more Westernized or Asian in appearance. While a post-surgical result may be acceptable and pleasing to a surgeon from one ethnic background, it may be not be pleasing to a surgeon from another background. More importantly, it is not clear whether the patients’ ethnic background plays a role in their esthetic preference and whether it is aligned with the preference and treatment plan of their surgeon. This may be problematic, particularly for patients of Asian ethnicity require orthognathic surgery living in the USA and planning their operation with a US-trained surgeon. The physician or surgeon’s ethnic background may influence the delivery of care and the treatment plan, but this factor is often overlooked . There are several studies in many areas of medicine examining the effects of ethnicity, racial identification, and acculturation (the immigrant’s process of readjustment and integration of beliefs and practices through interaction with other ethnic groups and exposure to the culture of the host society) on patients’ decisions about care, treatment, and healthcare access .

The purpose of this study is to determine whether there are differences in esthetic preferences and surgical treatment for Asian patients between US-trained and Asian-trained OMFS.

Materials and methods

Over a 6-month period in 2008, OMFS trained in the USA and Asia, including China, Japan, and Korea, participated in a University of California, San Francisco Institutional Review Board (UCSF IRB)-approved survey study. Participants were identified at professional conferences or association directories. To be included, the surgeon had to be at least 2 years beyond training, trained in the USA or Asia, be of Caucasian or Asian ethnicity, and able to fill out an English language survey. US-trained OMFS were categorized as Caucasian-American or Asian-American (defined as Americans of Asian ethnicity and born in the USA or born in Asia but who immigrated to the USA before the age of 6 years). Asian OMFS whose birthplace and place of training corresponded to their respective Asian country were included. Healthcare professionals who were not OMFS, not Caucasian or Asian, not trained in the USA or Asia were excluded. Surveys were distributed by hard copy or electronically and when completed were collected at professional conferences by two members of the research team (JJ, LHL). All other surveys were submitted electronically. The survey requested demographic data: age, gender, birth place, country of training, years since residency/fellowship training, ethnicity, culture with which they identify, and primary language. The survey consisted of profiles of an Asian male (Korean) and Asian female (Chinese) that demonstrated ‘normal’ profiles. Their profile photo was then digitally manipulated to create six other profiles that represented mild dentofacial variants ( Figs. 1 and 2 ; modified from the survey by S oh et al. ). The study models were dental students in their early twenties with normal, Class I appearing profiles and Class I occlusion, who volunteered for the study with consent and IRB approval. Lateral cephalograms were taken with lips in repose, teeth in maximum intercuspation and natural head position (Kodak WinOMS CS, v.8.0). They had normal cephalometric values, which were verified by Dolphin Cephalometric Analysis (v.10.5, Chatsworth, CA, USA) using Steiner–Tweed analysis (M4 of Fig. 1 , and F5 of Fig. 2 ). With Dolphin Analysis, six different profiles were generated from their baseline profiles; the upper or lower jaw or both were manipulated in an anteroposterior plane and within one standard deviation of normal. The cephalometric analyses and digital manipulations were performed by a single investigator. Photographs of the profile were converted to grayscale with Adobe photoshop (v.8.0) to limit visual distractions.

Fig. 1
Asian male facial profiles.

Fig. 2
Asian female facial profiles.

The surgeons were instructed to rank the seven Asian male and female profiles from most attractive (1) to least attractive (7) and indicate which facial feature(s) influenced the ranking: forehead, nose, upper lip, lower lip, chin, upper and lower lip, and upper lip, lower lip and chin. They were asked to recommend one of the following on the digitally manipulated Asian female and male profile with a mild maxillomandibular discrepancy and overjet of negative 2 mm: advance maxilla, setback mandible, or no surgery ( Fig. 3 ). Comparisons of the mean rank scores for the male and female profiles were performed for the three groups of surgeons, as well their preference of surgical treatment.

Fig. 3
Asian male and female profiles (a and b) demonstrating a negative overjet of 2 mm. Survey participants were asked to choose one treatment for each profile: (1) advance maxilla, (2) setback the mandible, or (3) do nothing.

Preference profile analyses were performed based on stepwise logistic regression models (alpha-in = 0.05, alpha-out = 0.05) with up to seven response levels (rankings 1–7) and with eight explanatory or independent variables: country of birth, country of medical school, country of post-medical school training, primary culture, primary language, gender, ethnicity and a grouping of surgeons as ‘Asian OMFS’ or ‘Asian-American OMFS’ or ‘Caucasian-American OMFS’. Mean rankings for each profile are presented for descriptive purposes. P -values from the logistic regression models are presented and p -values below 0.05 were considered statistically significant. All analyses were performed using SAS version 9.2 (SAS Institute, Cary, NC, USA).

Results

The results are described in Tables 1 and 2 . There were 76 participants. Four participants did not meet the inclusion criteria and were omitted from the study: two US-trained surgeons were neither Caucasian nor Asian in ethnicity and two healthcare professionals were not OMFS (an orthodontist and facial cosmetic surgeon). Of the remaining 72 participants, 25 were Caucasian-American, 23 were Asian-American, and 24 were Asian surgeons. The mean ages were 48.3 (range 37–64), 41.1 (range 34–60), and 44.5 (range 32–60) years, respectively. The Caucasian-American OMFS were on average 15.8 years (range 4–33 years) out of training with an average 5.1 years of training (range 3.5–7 years). The Asian-American surgeons were on average 8.3 years (range 2–29 years) out of training with an average 5.7 years of training (range 3–11 years). The Asian surgeons were on average 14.6 years (range 3–30 years) out of training with an average 4.9 years of training (range 3–6 years). There were 20 male and four female Caucasian-American surgeons, 21 male and three female Asian-American surgeons, and 22 male and two female Asian surgeons. All of the Caucasian-American surgeons were born in the USA, identified with American culture, and used English as their primary language. All 23 Asian-American surgeons identified with American culture, used English as their primary language, and received dental and medical school and residency training in the USA. If they were not born in the USA, they had immigrated to the USA before the age of 6 years. Within this group, there were five Korean surgeons who were born in Korea, one Korean surgeon who was born in the USA, and one Korean surgeon who failed to complete all the demographic data; two Japanese surgeons who were both born in the USA; two Chinese surgeons who were born in China, two Chinese surgeon born in Taiwan, two Chinese surgeons born in Hong Kong, four Chinese surgeons born in the USA, one Chinese surgeon born in Burma, and one Chinese surgeon born in Jamaica; and two Vietnamese surgeons born in Vietnam.

Table 1
Mean ranking of Asian male facial profiles.
M1
Protrusive maxilla/mandible mean (SD)
M2
Protrusive mandible mean (SD)
M3
Retrusive mandible mean (SD)
M4
Class I occlusion mean (SD)
M5
Retrusive maxilla mean (SD)
M6
Protrusive maxilla mean (SD)
M7
Retrusive maxilla/mandible mean (SD)
Caucasian-American OMFS N = 25 3.80 (1.66) 6.04 (48%) ** (1.11) 5.21 (1.93) 1.83 (56%) ** (1.41) 3.79 (1.48) 4.38 (1.96) 3.00 (1.02)
Asian-American OMFS N = 23 4.39 (1.44) 6.13 (57%) ** (1.49) 4.87 (1.87) 2.61 (48%) ** (2.02) 4.04 (1.55) 3.13 (1.94) 2.83 (1.15)
Asian OMFS N = 24 5.09 (1.12) 6.67 (75%) ** (0.64) 4.04 (2.20) 1.92 (50%) ** (1.18) 4.39 (1.47) 3.13 (1.01) 2.74 (1.60)
SD = standard deviation.

** Percentage that chose this category as most or least attractive profile.

Table 2
Ranking of Asian female facial profiles.
F1
Retrusive mandible mean (SD)
F2
Retrusive maxilla mean (SD)
F3
Protrusive maxilla/mandible mean (SD)
F4
Protrusive mandible mean (SD)
F5
Class I occlusion mean (SD)
F6
Protrusive maxilla mean (SD)
F7
Retrusive maxilla/mandible mean (SD)
Caucasian-American OMFS N = 25 5.00 (1.80) 5.48 (1.19) 4.24 (1.23) 5.68 (48%) ** (1.57) 2.12 (44%) ** (1.42) 2.72 (1.57) 2.68 (1.57)
Asian-American OMFS N = 23 4.48 (1.86) 5.87 (39%) ** (1.36) 4.78 (1.09) 5.78 (1.48) 1.91 (43%) ** (1.00) 2.52 (1.24) 2.65 (1.23)
Asian OMFS N = 24 2.96 (1.55) 6.04 (46%) ** (1.22) 5.58 (0.97) 5.78 (1.17) 2.74 (1.21) 3.00 (1.48) 1.92 (46%) ** (1.06)
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Feb 7, 2018 | Posted by in Oral and Maxillofacial Surgery | Comments Off on Orthognathic surgery for the Asian patient and the influence of the surgeon’s background on treatment
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