ORIGINAL ARTICLE Effects of playing a wind instrument on the occlusion Ektor Grammatopoulos,a Allan Paul White,b and Ashish Dhopatkarc Birmingham, United Kingdom Introduction: There is a popular belief among some musicians that playing a wind instrument regularly can af- fect the position of the teeth. The aim of this study was to investigate this hypothesis. Methods: A cross-sectional observational study was carried out, comparing the occlusions of 170 professional musicians selected from 21 orchestras and organizations in the United Kingdom. The subjects were subdivided according to type of instrument mouthpiece and included 32 brass players with large cup-shaped mouthpieces, 42 brass players with small cup-shaped mouthpieces, and 37 woodwind players with single-reed mouthpieces. Fifty-nine string and percussion players formed the control group. Impressions were taken of the teeth of each subject, and occlusal parameters were assessed from the study casts. The results were analyzed by using analysis of variance (ANOVA) and chi-square tests. Results: No statistically significant differences were found in overjet (P 5 0.75), overbite (P 5 0.55), crowding (maxillary arch, P 5 0.31; mandibular arch, P 5 0.10), irregularity index (maxillary arch, P 5 0.99; mandibular arch, P 5 0.16), and the prevalence of incisor classification (P 5 0.15) between the wind instrument players and the control group. However, the large-mouthpiece brass group had a significantly higher prevalence of lingual crossbites in comparison with all other groups. Conclusions: Playing a wind instrument does not significantly influence the position of the anterior teeth and is not a major etiologic factor in the development of a malocclusion. However, playing a brass instrument with a large cup-shaped mouthpiece might predispose a musician to develop lingual crossbites or lingual crossbite tendencies. (Am J Orthod Dentofacial Orthop 2012;141:138-45) popular belief among wind instrument players According to Proffit’s equilibrium theory,1 the posi- Aand their teachers is that playing a wind instru- tion of the teeth depends on forces exerted from the ment can lead to the development of malocclu- tongue and lips, forces from the dental occlusion, forces sion. Patients and their parents often ask dentists and from the periodontal membrane, and habits such as orthodontists whether playing a wind instrument can thumb sucking. The effects of digit and thumb sucking affect the position of teeth or whether the patient's mal- on the occlusion are well documented in the medical lit- occlusion is due to regular wind instrument playing. erature.2-6 Tooth movement requires the application of A review of the literature showed no clear agreement force exceeding a minimum threshold of magnitude in this area. As a result, it has been impossible to advise and duration. On a theoretical basis, playing a wind patients with any certainty about the potential effects of instrument might exert external forces to the occlusion playing a wind instrument on the occlusion. in a similar manner as thumb sucking, and hence might result in the development of malocclusion. The From the University of Birmingham, Birmingham, United Kingdom. pressure exerted by brass instruments on the teeth has aHonorary lecturer, School of Dental Sciences. been documented to be as high as, or even higher bStatistician. 7 c than, thumb sucking. In addition, there is little evidence Senior lecturer and honorary consultant, School of Dental Sciences, University of 8 Birmingham and Birmingham Dental Hospital. regarding the optimum magnitude of force, and various The authors report no commercial, proprietary, or financial interest in the animal studies have shown that a force duration of as products or companies described in this article. little as 8 hours a day results in tooth movement.9-11 Reprint requests to: Ektor Grammatopoulos, School of Dental Sciences, University of Birmingham, St Chads Queensway, B2 4NN, United Kingdom; A substantial part of the literature on the effects of e-mail, [email protected]. playing a wind instrument on the occlusion comprises Submitted, February 2011; revised and accepted, June 2011. expert opinions and anecdotal evidence based on ana- 0889-5406/$36.00 Copyright Ó 2012 by the American Association of Orthodontists. tomic assumptions and logic rather than on evidence- doi:10.1016/j.ajodo.2011.06.044 based research. 138 Grammatopoulos, White, and Dhopatkar 139 Strayer,12 a professional bassoonist and orthodontist, affect the validity of their conclusions. For example, po- was the first author to propose, based on observation, tential inaccuracies might have arisen because of a small that playing a wind instrument can affect the position sample size, the lack of a control group, or a biased con- of the teeth and therefore cause or correct a malocclu- trol group such as one comprising dental students or sion. He classified wind instruments into classes A, B, student dental assistants, or the inclusion of amateur C, and D and suggested that the effects of playing players, children and adolescents, subjects who had pre- a wind instrument on the position of the teeth might viously undergone orthodontic treatment, and subjects vary according to the type of mouthpiece and embou- from various ethnic groups. Furthermore, in these stud- chure that is involved (Fig 1). In the literature, other au- ies, the wind instrument players were often not sepa- thors (Porter13 and Dunn14) have since supported rated into groups or classes according to the type of Strayer’s observations and proposed similar theories. instrument or the shape of the mouthpiece, study casts It therefore seems possible to theorize, based on ob- were not usually taken, the examiners were rarely servation of the embouchure (Fig 1), that forces distrib- blinded, and the participants’ dental statuses were com- uted around the dentition when playing instruments monly not stated. could have the following effects for different classes of This study was devised to help provide evidence- instruments. based advice on whether playing a wind instrument Class A instruments can exert a horizontal force on affects the position of teeth or whether it is a causative the maxillary and mandibular incisors that might result factor in the development of malocclusion. Our aim in retroclination of maxillary and mandibular incisors was to assess whether playing a wind instrument has and lead to a reduction in overjet and an increase in an effect on the position of the teeth or causes a maloc- overbite. clusion. In particular, the objectives of this study were to: Class B instruments can exert horizontal and vertical 1. Determine if playing a wind instrument affects over- forces on the maxillary and mandibular incisors that jet, overbite, or the transverse molar relationship. might result in maxillary incisor proclination, mandibu- 2. Determine if playing a wind instrument causes lar incisor retroclination, intrusion of maxillary and crowding, irregularity, or alters the intermolar mandibular incisors, and therefore an increase in overjet widths. and a reduction in overbite. 3. Determine if there is a difference in the prevalence Class C instruments can exert horizontal and vertical of the incisor relationship and crossbites in brass forces on the maxillary and mandibular incisors that and woodwind players when compared with musi- might result in retroclination and intrusion of maxillary cians who do not play a wind instrument. and mandibular incisors and therefore a reduction in overjet and overbite. The null hypothesis was that there is no difference in Class D instruments can exert a horizontal force on the occlusions of professional wind instrument players the mandibular incisors that might result in retroclina- when compared with a control group of musicians tion of mandibular incisors and therefore an increase who do not play wind instruments. in overjet. Since the early observational evidence, numerous au- MATERIAL AND METHODS thors have attempted to examine over the last 3 decades Independent-group t test analysis estimated that 32 the effects of playing a wind instrument on the occlusion subjects per group were required to detect a difference more rigorously. The majority of the published studies of 2 mm in overjet among the various groups. This have been cross-sectional observational studies compar- was based on an alpha significance level of 0.05 with ing the study casts or the lateral cephalograms of wind 95% power. The standard deviation for the sample size instrument players with those of a control group. was calculated as 1.9 mm based on data from the Na- Parker15 and Rindisbacher16 concluded that playing tional Health and Nutrition Examination Survey III, a wind instrument has little, if any, effect on the occlu- which included detailed data on overjet across a large sion. On the contrary, Pang,17 Gualtieri,18 and population of white subjects.20 Brattstrom€ et al19 concluded that playing a wind instru- Ethical approval was obtained from the University of ment might affect the inclination of the maxillary and Birmingham Research and Ethics Committee and the mandibular incisors and therefore result in an increase Royal Northern College of Music Research and Ethics or a decrease in overjet or overbite. Committee in the United Kingdom. All subjects were In the context of currently accepted optimum re- treated according to the Declaration of Helsinki search practice, many of the previously reported studies (1964)21 and the British Psychological Society’s code might be considered to suffer from flaws that could of ethics and conduct (2006).22 Signed informed American Journal of Orthodontics and Dentofacial Orthopedics February 2012 Vol 141 Issue 2 140 Grammatopoulos, White, and Dhopatkar Fig 1. Strayer’s classification of wind instruments12: A, class A instruments with cup-shaped mouth- pieces (trumpet, French horn, trombone, and tuba); B, class B instruments with single-reed mouth- pieces (clarinet and saxophone); C, class C instruments with double-reed mouthpieces (oboe, English horn, and bassoon); D, class D instruments with aperture mouthpieces (flute and piccolo).