Effects of Playing a Wind Instrument on the Occlusion

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 affect 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 mouthpieces (trumpet, French horn, trombone, and tuba); B, class B instruments with single-reed mouthpieces (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). consent was obtained from each subject who partici- practiced on average at least 3 hours daily, and for at pated in the study. least the last 4 years, and started playing a wind instru- Various well-established and reputable professional ment before they were 14 years old. The control group orchestras, jazz bands, and music colleges were con- comprised professional string and percussion players tacted. The subjects comprised wind instrument players from the same orchestras and organizations as the of classes A and B (Strayer’s classifications),12 and the wind instrument players. control group comprised string instrument and percus- Wind instrument players who played more than 1 sion players, recruited from the same organizations. class of wind instruments either professionally or recrea- The subjects were therefore separated into 4 groups: (1) tionally, with the exception of single-reed players who players of large-mouthpiece brass instruments, such as the also played the flute or the piccolo, were excluded. String tuba and trombone; (2) players of small-mouthpiece brass and percussion players who played or used to play a wind instruments, such as the trumpet and French horn; (3) instrument recreationally were excluded. playersofsingle-reedinstrumentssuchastheclarinet In terms of their dental status, we excluded subjects and saxophone; and (4) players of string and percussion (wind, string, and percussion players) who had previ- instruments (control group). ously undergone orthodontic treatment; had extractions The subjects were selected from the following orga- of permanent teeth other than second and third molars; nizations: Royal Philharmonic Orchestra, City of Bir- had retained deciduous teeth or supernumerary teeth, mingham Symphony Orchestra, London Philharmonic crowns on permanent teeth other than first, second, Orchestra, Lucerne Symphony Orchestra, Oxford Philo- and third molars; had restorations on incisors and ca- musica, Royal Liverpool Philharmonic Orchestra, BBC nines that extended over 2 surfaces; or had pathology, Big Band, Welsh National Opera Orchestra, Halle, BBC including periodontal disease, previous fractures of the Philharmonic Orchestra, Opera North, National Saxo- maxilla or the mandible, and dental cysts. Subjects phone Choir, Clarinet and Saxophone Society, Trinity who admitted to a digit-sucking habit that persisted un- College of Music, BBC Scottish Orchestra, Royal National til the age of at least 10 years and subjects who smoked Scottish Orchestra, Royal Scottish Academy of Music and a pipe were also excluded. Drama, BBC Concert Orchestra, and Royal Welsh College The musicians who satisfied the criteria on the basis of Music and Drama. Furthermore, 2 organizations, the of written questionnaires had a brief examination of East London Clarinet Choir and the Notebenders Jazz their teeth. Those who were eligible to participate on Club, were visited, but no musician satisfied the selection the basis of the inclusion and exclusion criteria had im- criteria. pressions taken at their practice venues. Study casts were The included subjects were white men and women made and coded to preserve anonymity and ensure that who were professional wind instrument players, there was no observer bias during their assessment.

February 2012 Vol 141 Issue 2 American Journal of Orthodontics and Dentofacial Orthopedics Grammatopoulos, White, and Dhopatkar 141

Recruitment of participants stopped as soon as 32 when the palatal cusp of the maxillary first perma- musicians were obtained for each group, as dictated by nent molar occluded lingually to the central fossa the sample size calculation. A total of 170 musicians par- of the mandibular first permanent molar. Lingual ticipated in the study. They comprised 32 subjects in the crossbite was defined when there was cusp-to- large-cup brass group, 42 subjects in the small-cup brass cusp contact or more. group, 37 subjects in the single-reed group, and 59 sub- 3. Presence of buccal crossbites or buccal crossbite ten- jects in the control group. Inclusion of more than 32 dencies: a buccal crossbite tendency was defined subjects in the first 3 groups increased the statistical when the palatal cusp of the maxillary first permanent power of the study. molar occluded buccally to the central fossa of the The following features were assessed on the study mandibular first permanent molar. Buccal crossbite casts: (1) overjet (mm), (2) overbite (mm), (3) British was defined when the palatal cusp of the maxillary Standards Institute incisor relationship,23 (4) maxillary first permanent molar occluded on the buccal cusps and mandibular intermolar widths (mm), (5) crowding of the mandibular first permanent molar. in the maxillary and mandibular labial segments The descriptions and definitions of crossbites of (mm), (6) Little’s irregularity index (mm),24 and (7) American orthodontists are the opposite of the descrip- crossbites, with reference to the maxillary first perma- tion of the British Standards Institute classification that nent molars. defines a buccal crossbite as a transverse discrepancy in All measurements were made by 1 examiner (E.G.). tooth relationship where the buccal cusps of the man- Digital calipers were used to measure linear measure- dibular teeth occlude laterally to the buccal cusps of ments such as the overbite, intermolar width, and the maxillary teeth.23 crowding. The digital calipers were calibrated to ensure Before taking the measurements, the reproducibility accuracy on every 12 successive study casts. of the measurements was confirmed with a matched Incisor relationship was assessed according to the pairs t test by remeasuring 20 randomly selected study British Standards Institute incisor classification.23 This casts 9 days later. This confirmed that there was no sig- classifies incisor relationships as follows. nificant difference between initial and subsequent mea- Class I, the mandibular incisor edges occlude with or surements. lie immediately below the cingulum plateau of the max- One-way analysis of variance (ANOVA) was used to illary central incisors. compare the means of interval variables among the Class II, the mandibular incisor edges lie posterior to groups: overjet, overbite, crowding, Little’s irregularity the cingulum plateau of the maxillary incisors. There are index,24 and intermolar widths. The chi-square test 2 divisions. In Division 1, there is an increase in overjet was used to assess whether there was a difference in cat- and the maxillary central incisors are usually proclined. egorical variables among the groups: the proportions of In Division 2, the maxillary central incisors are retro- subjects with various incisor classifications and cross- clined. The overjet is usually minimal but might be bites. A retrospective sample size calculation, with the increased. standard deviation calculated from the data of the sub- Class III, the mandibular incisor edges lie anterior to jects of this study, confirmed that there was 83% to 98% the cingulum plateau of the maxillary incisors. The over- power for the analysis and comparison of all the other jet is reduced or reversed. occlusal features. To define the intermolar widths, the mesiobuccal fi cusps of the maxillary and mandibular rst molars RESULTS were taken as reference points. Little’s irregularity index, There were no statistically significant differences in which is the sum of the contact point displacements in the overjet (P 5 0.75), overbite (P 5 0.55), crowding the 6 anterior teeth, was measured as described by (maxillary arch, P 5 0.31; mandibular arch, P 5 0.10), Little.24 Little’s irregularity index (maxillary arch, P 5 0.99; On each pair of casts, the presence or absence of mandibular arch, P 5 0.16), and prevalence of incisor a transverse discrepancy of tooth relationship (crossbite) classification (P 5 0.15) among the various groups was scored as follows. (Tables I and II). 1. Absence of crossbite was defined when the palatal ANOVA and the Tukey post hoc test showed that the cusps of all maxillary molars occluded to the mid- large-cup brass group had a significantly wider mandib- point of the central fossa of the mandibular molars. ular intermolar width (P \0.001), whereas there was no 2. Presence of lingual crossbites or lingual crossbite significant difference in the maxillary intermolar width tendencies: a lingual crossbite tendency was defined (P 5 0.35). Furthermore, the large-cup brass group

American Journal of Orthodontics and Dentofacial Orthopedics February 2012 Vol 141 Issue 2 142 Grammatopoulos, White, and Dhopatkar

Table I. Results for overjet, overbite, labial segment crowding, Little’s irregularity index, intermolar width, and maxillary and mandibular intermolar comparisons

Large-cup brass Small-cup brass Single reed Control (trombone and (trumpet and (clarinet and (string and Signiﬁcance Instrument and variable tuba) French horn) saxophone) percussion) level Overjet (mm) 2.83 2.77 3.01 3.12 P 5 0.75 Overbite (mm) 2.74 2.48 2.72 3.06 P 5 0.55 Maxillary crowding (mm) 1.66 0.79 1.44 1.50 P 5 0.31 Mandibular crowding (mm) 2.34 1.33 1.65 2.32 P 5 0.10 Maxillary Little’s index (mm) 3.52 3.36 3.60 3.94 P 5 0.99 Mandibular Little’s index (mm) 4.50 3.33 3.90 4.37 P 5 0.16 Maxillary intermolar width (mm) 50.8 51.5 50.1 50.6 P 5 0.35 Mandibular intermolar width (mm) 47.6* 44.9 44.7 44.6 P 5 0.001* Maxillary – mandibular intermolar 3.93* 5.99 5.42 6.01 P 5 0.009* width (mm) Maxillary O mandibular intermolar 0.87* 1.13 1.23 1.14 P 5 0.006* width (mm)

*Statistically signiﬁcant difference.

Table II. Detailed data on overjet

Large-cup brass Small-cup brass Single reed Control All instrument (trombone and (trumpet and (clarinet and (string and Instrument and overjet groups tuba) French horn) saxophone) percussion) Mean overjet (mm) 2.96 2.77 2.83 3.01 3.12 SD 1.70 2.62 1.47 1.22 1.49 95% CI, lower bound (mm) 2.70 2.18 2.31 2.46 2.68 95% CI, upper bound (mm) 3.21 3.37 3.35 3.57 3.56 had a significantly lower mean maxillary minus mandib- sex had no effect on the severity or the prevalence of lin- ular intermolar width (P 5 0.009) and a significantly gual or buccal crossbite. lower ratio of maxillary intermolar width to mandibular intermolar width (P 5 0.006). Statistical analysis with DISCUSSION chi-square tests found that the large-cup brass players In this study, we focused on brass and single-reed had a significantly higher prevalence of lingual cross- instruments only, since results from previous crossbites compared with the other wind instrument groups sectional observational studies had shown that playing and the control group (P 5 0.008). one of these instruments has the most profound effect To confirm that sex was not a confounding factor for on the occlusion. It is a popular belief among musicians this difference in mandibular intermolar width and prev- and teachers that instruments of these classes exert the alence of lingual crossbites, further statistical analyses highest forces on the teeth and have the most pro- were performed. ANOVA with data excluded from nounced effect on the positions of the teeth. This is in women in all groups showed significant differences in keeping with the conclusions of previous researchers mandibular intermolar widths (P 5 0.031), mean maxil- who found that brass instruments, followed by reed in- lary minus mandibular intermolar widths (P 5 0.003), struments, exert the highest forces on the dentition.7 All and the ratios of maxillary intermolar width to mandib- subjects started playing a wind instrument in childhood ular intermolar width (P 5 0.026) for male musicians in or early adolescence. The brass players began playing an the large-cup brass group compared with the small-cup instrument on average at age 9 years 9 months, and the brass, the single-reed, and the control groups. However, single-reed players started at age 10 years 4 months. there was no significant difference in the maxillary inter- Brass and single-reed players practiced or performed molar width (P 5 0.84) for male musicians in the large- daily on average for 3.8 and 4.2 hours, respectively. cup brass group compared with the other experimental There is great variation in the sizes of the mouth- groups and the control group. Furthermore, a logistic re- pieces of class A instruments (Fig 2, A and B). Class A gression taking instrument into account confirmed that brass players were subdivided into those who play with

February 2012 Vol 141 Issue 2 American Journal of Orthodontics and Dentofacial Orthopedics Grammatopoulos, White, and Dhopatkar 143

a large cup-shaped mouthpiece (Fig 2, C and D) and those who play with a small cup-shaped mouthpiece (Fig 2, E and F), because the force exerted over a small surface area, such as with the mouthpiece of a trumpet, might be more potent than a force of the same magnitude exerted over a larger surface area, such as with the mouthpiece of a trombone. Unlike class A instruments, the size and the shape of the single-reed mouthpieces and the embouchures of a saxophone (Fig 2, G and H) and a clarinet (Fig 2, I and J) are similar. It is common for clarinet players to also play the saxophone recreationally and vice versa. Therefore, it was not deemed necessary to separate clarinetists and saxophonists into different groups. It is also common for class B players, in particular jazz players, to play a class D instrument (flute or piccolo) during their performances. Discussions with professional wind players supported the conclusion by Engleman7 that playing a class D instrument exerts low forces on the teeth because of the mechanism by which the embouchure is made and how the instrument is applied to the mouth for playing. Therefore, it was not necessary to exclude class B players who also played a class D instrument from the sample. There was an increased prevalence of buccal crossbite tendencies in the control group. Since there was no statistically significant difference in the maxillary or mandibular intermolar widths, no difference in mandibular divided by maxillary intermolar widths, or no difference in the maxillary divided by mandibular arch intermolar widths or maxillary minus mandibular arch intermolar width between the groups other than for the large-cup brass group, it is highly likely that this observation was due to chance alone. The difference in the mandibular intermolar width for the large-cup brass group might be because those players keep their mouths slightly more open during playing, since those mouthpieces are much larger than the Fig 2. There are wide variations in the size of mouth- small cup-shaped mouthpieces. This causes the tongue to pieces and embouchures between large cup-shaped and small cup-shaped brass instruments and few varia- adopt a more inferior position. This could be the reason tions in the embouchures of single-reed instruments: A for the greater mandibular intermolar width, which in and B, brass instrument mouthpieces in order of ascend- turn explains the increased prevalence of lingual cross- ing diameter: French horn, trumpet, trombone, and tuba; bites in the large-cup brass group. However, although C and D, tuba mouthpiece resting passively against the these differences were statistically significant, it is highly mouth of a nonmusician; E and F, French horn mouth- unlikely that they would be clinically significant or the piece resting passively against the mouth of a nonmusician. The diameters of the mouthpieces vary from 24.70 = to 28.00 mm for the French horn, 26.59 to 28.50 mm for single-reed player with a saxophone; I and J, embou- the trumpet, 37.92 to 40.46 mm for the trombone, and chure of a professional single-reed player with a clarinet. 44.28 to 47.35 mm for the tuba. Because of these varia- The embouchures of the clarinet and the saxophone are tions in size, a brass player with a large cup-shaped similar. Therefore, it is common for single-reed wind mouthpiece might tend to keep his or her mouth slightly players to play both instruments at a professional level more open than one who plays with a small cup-shaped (Dennis Wick mouthpieces, mouthpiece comparison mouthpiece. G and H, Embouchure of a professional chart. Available at: www.deniswick.com).

American Journal of Orthodontics and Dentofacial Orthopedics February 2012 Vol 141 Issue 2 144 Grammatopoulos, White, and Dhopatkar

presenting complaint of a patient; hence, the main con- “tooth damage or pushing in of the teeth.” Upon erup- clusion of this study is that playing a wind instrument tion of the central and lateral incisors at 6 to 8 years of has little effect on the positions of the teeth and is not age, on average, three quarters of their final root length an etiologic factor for the development of malocclusion is established,27 and root formation is completed at 8.6 even in subjects who play at a professional level. This to 9.8 years of age for the central incisors and 9.6 to could be due to at least 1 of the following reasons. 10.8 years for the lateral incisors.28 It is impossible to exclude from this study the possibility that the teeth 1. The magnitude of the forces exerted while playing might be more susceptible to tooth movement before a wind instrument do not exceed the threshold for the age of 8 years as a result of the force exerted by tooth movement. the mouthpiece of a musical instrument on a regular 2. The duration of the force applied while playing basis. The teeth at this stage have immature roots, a wind instrument might not exceed the threshold and the alveolar bone is elastic, so it is conceivable of force duration for tooth movement. Even the that they could be more susceptible at this stage. It is most skilled wind instrument players, who play in also uncertain whether this sustained pressure on the most renowned orchestras and bands, play a tooth with immature roots can also lead to dilacera- and practice on average approximately 4 hours tion of the root. For these reasons, we believe that the daily. This might not exceed the threshold of force advice currently given by music teachers should not duration for tooth movement. change. 3. Unlike the forces applied by orthodontic appliances and thumb sucking, forces applied during wind instrument playing are not continuous, since the CONCLUSIONS players typically take breaks during practice and 1. Playing a wind instrument does not significantly performance. affect anterior tooth position. 4. Forces by the mouthpiece on the teeth are cush- ioned by the lips. 2. Playing a brass instrument with a large cup-shaped 5. The resting force from the lips, cheeks, and tongue, mouthpiece, such as the trombone and tuba, might pose a small risk for the musician to develop and swallowing and occlusion while the person is a lingual crossbite. not playing or practicing might be more important in determining the position of the teeth than the We thank the musicians, directors, conductors, man- force exerted while playing the instrument. agers, teachers, and supporting staff from the aforemen- 6. Forces exerted by the mouthpiece and the tensed tioned organizations for their participation and interest facial musculature might be balanced. in this study; Lorraine Barreto for her support; and Since we found little effect of playing a wind instrument Rognvald Linklater for his inspirational idea to investi- on the occlusion of professional wind instrument players, it gate the wind instrument-orthodontic interface. is highly unlikely that the occlusion of amateur players who play or practice fewer hours than professionals would be affected. REFERENCES Perhaps many musicians firmly believe that playing 1. Proffit WR. Equilibrium theory revisited: the factors influencing a wind instrument affects the positions of their teeth be- position of the teeth. Am J Orthod 1977;48:175-86. fi cause they or their colleagues have experienced late 2. Prof t WR, Fields HR. Contemporary Orthodontics. 3rd ed. St. Louis, Mo: Mosby; 2000. mandibular incisor crowding. With limited knowledge 3. Graber TM. Thumb- and finger-sucking. Am J Orthod 1959;45: of the etiology of such a common condition, a musician 258-64. might attribute this to playing a wind instrument. The 4. Larsson E. The effect of finger-sucking on the occlusion: a review. etiology of mandibular incisor crowding is multifacto- Eur J Orthod 1987;9:279-82. rial, and various etiologic factors have been suggested 5. Moore MB, McDonald JP. A cephalometric evaluation of patients 25 presenting with persistent digit sucking habits. Br J Orthod and investigated. Increases in mandibular incisor irreg- 1997;24:17-23. ularity occur throughout life in many subjects who have 6. Mistry P, Moles DR, O’Neill J, Noar J. The occlusal effects of digit had or have not had orthodontic treatment.26 sucking habits amongst school children in Northamptonshire (UK). Based on discussions with numerous music teachers J Orthod 2010;37:87-92. in a variety of orchestras, jazz bands, and music col- 7. Engelman JA. Measurement of perioral pressures during playing of musical wind instruments. Am J Orthod 1965;51:856-64. leges, we noted that wind instrument teachers often 8. Ren Y, Maltha J, Kuijpers-Jagtman AM. Optimum force magnitude dissuade young musicians from playing a brass instru- for orthodontic tooth movement: a systematic literature review. ment before the age of 8 years old in order to avoid Angle Orthod 2003;73:86-92.

February 2012 Vol 141 Issue 2 American Journal of Orthodontics and Dentofacial Orthopedics Grammatopoulos, White, and Dhopatkar 145

9. Hayashi H, Konoo T, Yamaguchi K. Intermittent 8-hour activation 19. Brattstrom€ V, Odenrick L, Kvam E. Dentofacial morphology in chil- in orthodontic molar movement. Am J Orthod Dentofacial Orthop dren playing musical wind instruments: a longitudinal study. Eur 2004;125:302-9. J Orthod 1989;11:179-85. 10. Owman-Moll P, Kurol J, Lundgren D. Continuous versus interrup- 20. Profﬁt WR, Fields HW, Moray LJ. Prevalence of malocclusion and ted continuous orthodontic force related to early tooth movement orthodontic treatment need in the United States: Estimates from and root resorption. Angle Orthod 1995;65:395-401. the NHANES III survey. Int J Adult Orthod Orthognath Surg 11. Kumasako-Haga T, Konoo T, Yamaguchi K, Hayashi H. Effect of 1998;13:97-106. 8-hour intermittent orthodontic force on osteoclasts and root re- 21. Declaration of Helsinki. World Medical Organization. BMJ 1996; sorption. Am J Orthod Dentofacial Orthop 2009;135:278.e1-8. 313:1448-9. 12. Strayer ER. Musical Instruments as an aid in the treatment of mus- 22. British Psychological Society. Code of ethics and conduct 2006. cle defects and perversions. Angle Orthod 1939;9:18-27. Available at: www.bps.org.uk. Accessed on September 1, 2008. 13. Porter MM. Dental aspects of orchestral wind instrument playing with 23. British Standards Institute. Glossary of dental terms (BS 4492). special reference to the “embouchure.” Br Dent J 1952;93:66-73. London, United Kingdom: BSI; 1983. 14. Dunn RH. Selecting a musical wind instrument for a student with 24. Little RM. The irregularity index: a quantitative score of mandib- orofacial muscle problems. Int J Orthod 1982;20:19-22. ular anterior alignment. Am J Orthod 1975;68:554-63. 15. Parker J. The Alameda instrumentalist study. Am J Orthod 1957; 25. Harradine NW, Pearson MH, Toth B. The effect of extraction of 43:399-415. third molars on late lower incisor crowding: a randomized con- 16. Rindisbacher T, Hirschi U, Geering A. Little inﬂuence on tooth posi- trolled trial. Br J Orthod 1998;25:117-22. tion from playing a wind instrument. Angle Orthod 1989;60:223-8. 26. Richardson ME, Gormley JS. Lower arch crowding in the third 17. Pang A. Relation of musical wind instruments to malocclusion. decade. Eur J Orthod 1998;20:597-607. J Am Dent Assoc 1976;92:565-70. 27. Gron AM. Prediction of tooth emergence. J Dent Res 1962;41:573-85. 18. Gualtieri PA. May Johnny or Janie play the clarinet? Am J Orthod 28. Welbury RR. Paediatric dentistry. 2nd ed. Oxford, UK: Oxford 1979;76:260-76. University Press; 2001.

American Journal of Orthodontics and Dentofacial Orthopedics February 2012 Vol 141 Issue 2