J Oral Maxillofac
Surg
49:1274-1291.1990
Speech, Velopharyngeal Function, Hearing Before and After Orthogna thic Surgery LINDA
D. VALLINO,
and
PHD*
Articulation, voice, resonance, hearing sensitivity, and middle ear function were examined in 34 patients before and 3, 6, 9, and 12 months after orthognathic surgery. Thirty of the 34 patients had articulation errors before surgery. Errors on the sibilants /s/ and /zl occurred most frequently, followed by those on /j,zh,ch/ and lshl. Errors were predominantly distortions with both visual and acoustic components. After surgery, articulation improved spontaneously in the absence of intervention. Most of the preoperative articulation errors were eliminated by 3 months postoperative, but, thereafter, a gradual decline was noted so that by 12 months, errors occurred on /s/ and /z/. Voice, resonance, velopharyngeal port area, and hearing sensitivity were not altered by surgery. This study suggests that severe skeletal malocclusions requiring surgical correction have deleterious effects on the patients’ articulation of consonants and that surgical alteration leads to the correction of most of these errors.
Severe dental and skeletal malocclusions can have varying detrimental effects on mastication, appearance, and speech production. The treatment of such conditions generally requires both orthodontic and orthognathic surgical procedures involving the maxilla, the mandible, or both.’ The effects of orthognathic surgery on consonant articulation, the most frequently studied aspect of speech, are equivocal. Although most investigators 2-9have reported improved sound production after surgery, particularly on /s/ and lzl, otherslO~” have not concurred. Only a few studies5*‘0~‘2*‘3have
explored resonance and velopharyngeal function, both of which may be altered after advancement of the maxilla. Furthermore, the only studyI that examined voice quality showed that it did not change after surgery. Measurements of hearing sensitivity and middle ear function have received minimal attention in patients with orthognathic problems requiring correction. Although two investigations149’5 have reported no clinically significant changes in hearing thresholds after surgery, negative middle ear pressure has been documented in patients shortly after maxillary osteotomy. r6-r8 This latter condition was noted to subside within 3 to 12 weeks. The purpose of this study was to evaluate articulation, voice, resonance, velopharyngeal function, hearing sensitivity, and middle ear status before and after orthognathic surgery.
* Formerly, The University of Pittsburgh Cleft Palate and Craniofacial Center; currently, Speech-Language Pathologist/ Clinical Audiologist, Department of Speech Pathology, and Member, Craniofacial Treatment and Research Centre, The Hospital for Sick Children, Toronto, Ontario, Canada. Portions of this article were presented at the 45th Annual Meeting of the American Cleft Palate Association, Williamsburg, VA, April 1988, and at the 46th Annual Meeting of the American Cleft Palate Association, San Francisco, April 1989. This research was supported in part by Public Health Grant Number DE01697. Address correspondence and reprint requests to Dr Vallino: Department of Speech Pathology, The Hospital for Sick Children, 555 University Ave, Toronto, Ontario MSG 1X8, Canada. 0 1990 American geons
Association
of Oral and Maxillofacial
Materials and Methods SUBJECTS
Thirty-four subjects, 24 females and 10 males between the ages of 14 and 48 years (mean, 25.5; SD, 7.Q were referred to the University of Pittsburgh Cleft Palate-Craniofacial Center for examination by two maxillofacial surgeons in Pittsburgh, Pennsyl-
Sur-
0278-2391/90/4812-0006$3.00/O
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LINDA D. VALLINO
vania. None of the patients had a history of cleft palate, craniofacial anomaly, or mental retardation. Ten had undergone previous speech therapy, but were not enrolled in such a program at the time of this investigation. Eleven subjects had a class II malocclusion, 12 had a class II malocclusion with an open bite, 6 had a class III malocclusion, and 5 had a class III malocclusion with an open bite. One of three types of surgical procedure was performed: the Le Fort I maxillary osteotomy, the bilateral sagittal split osteotomy, or the combined Le Fort I and bilateral sagittal split osteotomy (Table 1). Subjects were examined for speech and hearing assessments preoperatively and 3, 6, 9, and 12 months postoperatively. The first postoperative examination was conducted at 3 months because the subjects were in maxillomandibular fixation for 8 weeks after surgery. The number of postoperative assessments varied between subjects because they did not always keep appointments. CLINICAL
Speech
ASSESSMENTS
Assessment
Articulation was evaluated using the picture form of the Fisher-Logemann Test of Articulation Competence.” The number of errors was counted and the type was classified as a substitution, omission, or distortion error. Distortions were further categorized as visual, acoustic, or combined visual and acoustic (Table 2). The nature of the errors was described according to the way in which the error was made relative to the dental malocclusion and each was placed into one of seven categories (Table 3).9 Voice and Resonance
Variables of voice quality, such as breathiness, harshness, and stridency, appeared on the original rating form but none of the subjects exhibited any of these characteristics. Hence, quality was judged by the presence or absence of hoarseness; pitch was Table 1. Type of MaJocclurion and Dercrlptien of Surgical Procedures Used to Treat 34 Subjects Type of Malocclusion Type of Surgery
ClaSS II
Open Bite
Class III
Class III Open Bite
Le Fort I osteotomy Sag&al split osteotomy Combined procedures Total
0 11 0 11
3 0 9 12
0 2 4 6
1 0 4 5
ClassII
Table 2.
Definitions of Error Type
Substitution. One sound is replaced by another (eg, rat for cat). Omission. Sound is omitted from the word (eg, _at for cat). Distortion. Sound is not produced in appropriate manner but is still recognizable to the listener. Visual distortion. Appearance of the sound is abnormal but the sound itself is correct (eg, lower lip makes contact with upper teeth for bilabial sounds /p,b,m/). Auditory distortion. Perception of sound is abnormal but the appearance is correct. Combined visuallacoustic distortion. Both appearance and perception of sound are abnormal.
described as normal or abnormal. Resonance rated as hyponasal, normal, or hypernasal. Velopharyngeal
was
Port Area
Estimation of the size of the velopharyngeal port area was obtained with the pressure-flow technique described by Warren and DuBois.*’ The instrumentation and procedures have been described in detail elsewhere.20,21 Subjects were asked to repeat sentences having words containing the pressure sounds /p/ (as in puppy) and /s/ (as in sissy). These sounds were selected because they require a tight velopharyngeal seal. The single word hamper was also repeated because it contains the /-mp/ blend, which places stress on the velopharyngeal mechanism, thus closely resembling ongoing speech production.2’ Various degrees of velopharyngeal competency were determined by the pressure-flow measurements as categorized by Warren.*] An estimated area of 0 to 0.01 cm2 suggests adequate velopharyngeal closure; 0.01 to 0.015 cm*, adequate to borderline velopharyngeal closure; 0.015 to 0.02 cm2, borTable 3. Qlosury of Terms Used to Describe the Nature of Articulation Errors Frontal distortion, type I. Tongue tip is protruded between the upper and lower teeth. Frontal distortion, type II. Tongue tip is placed too far distally to the mandibular incisors while the tongue body is flattened, causing the air stream to be scattered. Denfalization. Tongue tip is placed against the superior surface of the upper or lower teeth. Lateralization. Air stream is diverted off to one or both sides of the tongue. Whistling. High-frequency sound is created by the air passing between the tongue and alveolar ridge. Mandibular movement. Mandible is positioned anteriorly or shifts laterally. Labiodentulization. Lower lip makes contact with the maxillary incisors. Data from Vallino.9
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SPEECH, VELOPHARYNGEAL
derline to inadequate velopharyngeal closure; and greater than 0.02 cm*, inadequate closure. Hearing Sensitivity Ear Function
and Middle
Hearing sensitivity was assessed with a Beltone (Chicago, IL) 200C two-channel audiometer. Both air and bone conduction thresholds were obtained. The frequencies for air conduction testing were 250, 500, 1,000, 2,000, 4,000, and 8,000 Hz bilaterally; bone conduction testing included all octave frequencies except 8,000 Hz. A Madsen impedance bridge (Model 2073; Madsen Electronics, North Tonawanda, NY) was used to determine middle ear function. Measurements of middle ear compliance, pressure, and curve gradient were obtained and classified according to the system suggested by Paradise et al.** Reliability Inter-judge reliability was established between the investigator and one other certified speech pathologist during live-speech evaluation. Agreement was 93% for articulation and 100% for voice quality, pitch, and resonance. Interjudge and intrajudge reliability for measurements of middle ear function was determined between the primary investigator and another certified audiologist. Interjudge agreement was 93% for pressure, 95% for compliance, and 93% for curve gradients. Intrajudge reliability was 95% for pressure and 97% for both compliance and curve gradients. Results SPEECH ANALYSIS
The preoperative and postoperative articulatory productions of the subjects were first analyzed as a whole group without consideration given to type of malocclusion. To compare the effects of types of malocclusion on articulation, the subjects were regrouped according to presence of closed bite or open bite. ENTIRE GROUP
Preoperatively, 30 of the 34 subjects (88.2%) had articulation errors. The number of errors ranged from 0 to 33, with a mean of 15.8 (SD, 9.1). The phonemes most frequently in error were the sibilants Is/ and /z/, followed by /j,zh,ch/ and IshI. Those least frequently involved were the tip alveolars /t,d,n/ and bilabials /p,b,m/. All errors consisted of distortions, predominantly both visual and
FUNCTION, AND HEARING
acoustic for sibilants, and visual only for tip alveolars and bilabials. Sibilant errors were characterized primarily by frontal distortions type II, followed by frontal distortions type I. All bilabial errors consisted of labiodentalizations, whereas tip-alveolar errors consisted of either dentalizations or frontal distortions type I. After surgery, 30 of the 34 subjects (88.2%) manifested a reduced number of errors in their final postoperative assessment. The data summarized in Table 4 suggest that there was a tendency for the preoperative articulation errors to improve after surgery. Subjects either eliminated their previous errors completely or, for those errors retained, reduced their number. None demonstrated a deterioration in speech production. Four subjects had no errors before or after surgery. The greatest change in articulation occurred at 3 months postoperatively, at which time the number of errors ranged from 0 to 24 with a mean of 7.3 (SD, 8.2). This was followed by a continued gradual decline in the mean number of articulation errors between 3 and 12 months. By 12 months, the number of errors ranged from 0 to 13 with a mean of 2.7 (SD, 2.3) (Fig 1). Wilcoxon’s matched-pair signed ranks test showed a statistically significant improvement in articulation at all four postoperative evaluations, as well as between the 3- and 12-month postoperative tests (P < .Ol). The percentage of phonemes produced incorrectly gradually decreased at each evaluation so that by 12 months errors remained only on /s/ and izl. At this 1Zmonth postoperative evaluation, the frequency of errors on Jsl was 20% and on lzl was 23.5%, as compared with the preoperative error percentages of 79.4 and 77.5, respectively. Bilabial errors on /p,b,m/ were completely eliminated by 3 months and tip-alveolar errors on /t,d,n/ by 6 months (Fig 2). Errors on sibilants consisted of combined visual and acoustic distortions, characterized mostly by frontal distortions type II. Table 4. Number of Subjects With Changes in Articulation Errors After Surgery Entire Group
Closed Bite
Open Bite
Preoperative Without errors With errors
4 30
1
3
16
14
Postoperative Unchanged Eliminated errors Reduced errors Deterioration
4 17 13 0
1 8 8 0
3 9 5 0
LINDA D. VALLINO
1277
oJ,
t 3 mos post op
Preop
6 mos post op
9 mos post op
12 mos post op
ASSESSMENTS
FIGURE 1.
number of articulation errors for all subjects before and after surgery. Mean
CLOSED-BITE AND OPEN-BITE GROUPS Before surgery, 16 of the 17 (98%) subjects with closed bites and 14 of the 17 (82%) subjects with open bites demonstrated articulation errors. The number of errors in the closed-bite group was larger (mean, 17.9; SD, 9.6) compared with those in the open-bite group (mean, 9.3; SD, 6.9). The errors made by subjects, irrespective of the type of malocclusion, involved 12 of the 24 phonemes tested. For both groups the phonemes most frequently in error were the sibilants Is.1 and /z/, followed by /j,zh,ch/, and /sh/. Errors on the tip alveolars /t,d,n/ and bilabials /p,b,m/ were made less often. When the nature of the sound errors was examined, sibilant errors in both groups were characterized primarily by frontal distortions type II and type I, in that order. Additional types of distortions
0
PREOP
0
POSTOP
noted during the production of the sibilant sounds by subjects with closed bites included whistling, interdentalizations, and lateral shifts of the mandible, whereas those with open bites lateralized their tongues. Regardless of the type of malocclusion, all bilabial errors were characterized by labiodentalizations, and tip-alveolar errors by dentalizations. After surgery, 16 of the 17 (94%) subjects in the closed-bite group and 14 of the 17 (82%) subjects in the open-bite group spontaneously exhibited reductions in the number of preoperative articulation errors (Table 4). Although the number of errors was reduced in both groups, the pattern of change differed. The most improvement occurred in the closed-bite group at 3 months, at which time the number of errors ranged from 0 to 17 with a mean of 5.2 (SD, 5.9), as compared with a preoperative range of 0 to 33 with a mean of 17.9 (SD, 9.6). From 3 to 9 months, the mean number of errors was essentially unchanged. At 12 months, another reduction occurred, dropping the mean number of errors further to 3.0 (SD, 5.2). In contrast, the change in the mean number of errors in the open-bite group at 3 months was minimal. The range was from 0 to 24 with a mean of 8.6 (SD, 9.3) compared with a preoperative range of 0 to 33 with a mean of 9.3 (SD, 6.9). The most notable change occurred at 6 months, followed by a gradual decline in errors to a mean of 1.5 (SD, 3.9) at 12 months, which is smaller than the mean of 3.0 (SD, 5.2) noted in the closedbite group (Fig 3). There were no statistically significant differences between the closed-bite and open-bite groups before surgery nor at 3 and 12 months after surgery. Articulation scores in the closed-bite group were consistently above the median at all three of these evaluation periods. After surgery, the percentage of involved individ-
n
Cbsed txte QrWP 0 Open bite group
01
s
j
j
ch
sh
t
n
p
b
m
PHONEMES
FIGURE 2.
of errors for individual phonemes before and 12 months after surgery for all subjects. Percentage
>
Pre op d
3 mos post op
6 mos post op
9 mos post oP
12 mos post oP
ASSESSMENTS
FIGURE 3. Meannumber of articulation errors for closed-bite and open-bite malocclusion groups before and after surgery.
1278
SPEECH, VELOPHARYNGEAL
ual phonemes decreased at each postoperative period so that by 9 months, errors were found only on /s/ and /z/ in the open-bite group. This change took as long as 12 months to occur in the closed-bite group (Fig 4). In both groups, the sibilant errors were characterized mostly by frontal distortions type II. However, the more varied speech errors in the closedbite group included errors of interdentalizations, mandibular shifting, and whistling. Subjects with open bites also exhibited dentalizations. VOICE AND RESONANCE
Before surgery, 2 of the 34 subjects, each having a closed-bite malocclusion, had hyponasality. Three months after surgery, the 24 subjects who were reevaluated all demonstrated normal resonance, including the 2 who had previously been hyponasal. Resonance did not deteriorate in any of the subjects. VELOPHARYNGEALPORT AREA
All subjects demonstrated estimated velopharyngeal port areas measuring between 0 and 0.049 cm*, indicating adequate velopharyngeal competency both before and after surgery across all speech tasks. HEARING SENSITIVITYAND MIDDLE EAR FUNCTION
Pure-tone hearing sensitivity was not adversely affected by orthognathic surgery. All subjects were considered to have normal thresholds for the speech frequencies. Middle ear compliance and curve gradient were unchanged by surgery. One subject who com-
s
z
j
zh
ch
sh
I
d
n
p
b
m
PHONEMES
FIGURE 4. Percentage of errors for individual phonemes before and 12 months after surgery for closed-bite and open-bite malocclusion groups.
FUNCTION,
AND HEARING
plained of stuffiness in the left ear 3 months after surgery demonstrated clinically significant negative middle ear pressure measurements. This individual had exhibited normal pressures bilaterally before surgery. Sudafed (pseudoephedrine, Burroughs Wellcome Inc) was prescribed, but the condition had not resolved by the end of the study. Hearing sensitivity was, however, clinically normal. Another subject, who also had normal pressure before surgery, showed bilateral negative pressures postoperatively. This condition gradually improved in the left ear to what was deemed clinically normal pressure at 12 months, but mild negative pressure persisted in the right ear. Discussion The results of this study continue to support the notion that malocclusions requiring orthognathic surgery have deleterious effects on speech. The data further show that specific types of malocclusions may influence speech more than others. As demonstrated, the mean number of preoperative errors was greater for the group of subjects who had a closed-bite malocclusion than those who had an open-bite malocclusion. This is contrary to what has been documented in the literature about the relationship between open bites and consonant defects.23 This study also supports claims that orthognathic surgery used to correct occlusal defects leads to improvement in articulation in most cases.2-9 Most of the subjects in this investigation eliminated all of their articulation errors; those who retained errors showed a reduction in their number. The four subjects who did not have preoperative errors may have learned to compensate for severe occlusal defects or may have had physical characteristics that would have explained, at least in part, their articulation patterns. Nine of 10 subjects had undergone previous speech therapy for improvement of sibilant productions, but to no avail. These findings underscore the idea that speech therapy is generally not effective in the treatment of individuals with severe malocclusions. Additionally, age did not seem to be an influencing factor in the degree of articulatory improvement. The number of subjects under 16 years was only three, making appropriate comparisons difficult. However, perusal of the data showed that two of these subjects (ages 14 and 16 years) continued to have mild sibilant errors at 12 months postoperatively. Although subjects from the closed-bite and openbite groups demonstrated improvement in articulation after surgery, it is the pattern of articulatory changes that distinguish the two groups. Improvement in the closed-bite group was greater at 3
LINDA D. VALLINO
months than in the open-bite group, but reached a plateau thereafter. In contrast, the reduction in the mean number of errors in the open-bite group was minimal at 3 months, but continued to decline over time. By 12 months, the open-bite group had fewer errors than the closed-bite group, as was the case before surgery. The subjects with closed bites appeared to have a difficult time making adjustments to a newly created oral environment that presumably would promote improved articulatory positioning. In these cases, the subjects attempted to maintain an abnormal tongue posture by varying the preoperative position of the tongue. For example, subjects demonstrating frontal distortions type II and mandibular shifting on sibilants before surgery experienced whistling or interdentalizations on these sounds after surgery. The high percentage of preoperative errors occurring on the sibilants, particularly on /s/ and /z/, suggests that these sounds are the phonemes most sensitive to variations in the oral structures. Thus, improved dental relationships promote an environment that seems to allow the tongue to assume a new posture that permits the narrow channeling of the airstream necessary for correct production of sibilants. Only distortion articulation errors were found in any of the subjects either before or after surgery. More specifically, combined visual and acoustic distortions occurred more frequently on sibilants than did isolated visual or isolated acoustic errors. That is, they looked and sounded incorrect. Visual distortions without acoustic components occurred on every error involving tip-alveolar and bilabial phonemes. Although these sounds were always judged to be acoustically correct, they were produced in a manner that looked aberrant to the observer. These visual distortions were readily eliminated by surgical correction of the malocclusion, whereas those having an acoustic component were more resistant to modification. The observation that the improvement in articulation in most of the subjects was spontaneous, without the benefit of speech therapy in the interim, seems to support the supposition that the tongue can easily make adjustments within the new oral environment. It also suggests that if a person eliminates errors, it is unlikely that these errors will recur. When the data for the entire group are analyzed, it appears that the most important time to evaluate speech is about 3 months after surgery, However, when the type of malocclusion is taken into consideration, it is clear that for some individuals, such as those with open-bite malocclusion, improvement is most noticeable 6 months after sur-
1279 gery. It is in these cases that the timing of recall for clinical examination may differ. Nonetheless, it is important to realize that in any patient, improvement may continue for as long as 1 year postoperatively. For patients who have persistent speech errors, but are stimulable for correct production, speech therapy should be recommended. Many of the errors were produced inconsistently; that is, the subjects were able to produce most sounds correctly some of the time. This ability is thought to be a positive indicator of the eventual elimination of errors with therapy. Given the different rates of spontaneous speech improvement to which specific types of malocclusion are prone, the timing of intervention may also vary. Based on this information, we may be in a better position to create programs that would maximize a patient’s learning potential. The fact that the examiner and a trained observer documented the sound productions during a live interview raises speculation about listener bias. This is certainly plausable and indicates a limitation of this investigation. The procedures Dalston and Vig” used in their study, in which preoperative and postoperative audiotape recordings of the speakers were randomly dubbed onto a master tape for listeners to rate, could have reduced this problem. However, this procedure eliminates the advantage of visualizing the way in which the individual produces the sound relative to dental structures. Although audiotape records provide a useful, permanent record of the speech sample for use in the comparison and acoustic analysis of pretreatment and posttreatment speech patterns, these recordings are limited because mild sibilant distortions may not be audible on tape, making narrow transcription of the error sound virtually impossible. The addition of videorecording helps capture the visual image but the audiosignal may still limit the assessment to traditional scoring techniques, such as noting correct or incorrect sound productions, substitutions, omissions, or distortions. Additional detailed information is critical for describing errors related to malocclusions, as well as for assessing the effect of treatment. The issue of occlusal relapse, always of concern to the maxillofacial surgeon, should also concern the speech pathologist. In those patients who retained speech errors, possible dental/skeletal relapse may have occurred. If such a condition existed, the individual would likely find it difficult to produce a correct sound, particularly the sibilant, because the oral environment would not be conducive to permitting the narrow anterior airstream necessary for its correct production. This was not
1280 tested in this study, but certainly warrants future investigation, Orthognathic defects do not appear to be associated with voice disorders, nor does orthognathic surgery affect voice quality or pitch. The findings of this study are consistent with those of Orentlicher et al.r4 Although the development of hypernasal speech after maxillary advancement is always of prime concern to both the patient and the clinician, the subjects in this study were not adversely affected. The hyponasality found in two subjects may have been the result of a blocked or partially occluded nasal airway caused by an undiagnosed condition such as edema, allergy, a cold, or some other problem. Improvement may have been due to the amelioration of a cold or allergy on the day of testing, or the altered jaw relationships may have enlarged the nasal or pharyngeal airway, thus providing a better passageway for nasal airflow, as others have observed. 10,24*25 Although investigators 12,13*26have documented hypernasality in noncleft individuals after maxillary advancement, this study substantiated the findings of other investigators5~‘0~13~27~28 who indicated that their noncleft subjects did not develop hypernasal speech after a similar procedure. Epker and Wolford26 stated that when the velopharyngeal valving mechanism is competent preoperatively, it remains unchanged postoperatively. The estimated sizes of the velopharyngeal port areas were consistent with adequate velopharyngeal competency both before and after surgery. These results are consistent with those of McCarthy et al28 and Dalston and Vig.” Although all subjects undergoing maxillary orthognathic procedures should be counseled about the possibility of alterations in velopharyngeal valving and in the resonance characteristics of speech, they can safely be assured that the risk is minimal unless borderline velopharyngeal competency is present. The latter is particularly true in those individuals with a cleft palate before surgery. Pressure-flow measurements are useful. They are advocated as a method for the routine quantification of the estimated size of the velopharyngeal port area, for the detection of those subjects at increased risk for velopharyngeal incompetency, and for the evaluation of the outcome of treatment. Visualization procedures such as videofluoroscopy and nasopharyngoscopy are also valuable adjuncts to the examination protocol. This study’s findings that pure-tone hearing sensitivity was not adversely affected by orthognathic surgery concur with those of Garber et all5 and Orentlicher et alI4
SPEECH, VELOPHARYNGEAL
FUNCTION,
AND HEARING
The number of cases in which negative middle ear pressures occurred after orthognathic surgery was small. Perhaps surgery induces a mechanical dysfunction of the eustachian tube because of swelling or perhaps it exacerbates a preexisting problem. Because anesthesia is administered through nasotracheal intubation, it is possible that changes in middle ear pressure in one ear may be the result of prolonged intubation on that side, thus causing a temporary obstruction of the eustachian tube.‘“18 Prolonged maxillomandibular fixation may impair adequate ventilation of the middle ear and eustachian tube, the effects of which have not been thoroughly investigated. Much more exploratory work is required in this area, including presurgical and postsurgical evaluation of eustachian tube function, as well as intraoperative testing. Audiologic assessment should be conducted before and after surgery. Tympanometric evaluations are valuable when the maxilla is being repositioned. When negative middle ear pressure persists after surgery, eustachian tube function tests should be considered. Acknowledgment The author would like to thank Drs Betty Jane McWilliams, John Pierce, Joseph Andrews, and Mark Previtt for their assistance during this study. This article was prepared with the assistance of Medical Publications, The Hospital for Sick Children, Toronto.
References 1. Bell WH (ed): Surgical Correction of Dentofacial Deformities. vol 3. Philadelnhia. PA. Saunders. 1985 2. Glass L, Knapp J, Bloomer HH: Speech and lingual behavior before and after mandibular osteotomy. J Oral Surg 35: 104, 1977 3. Weimer K, Astrand P: Effect on speech of mandibular prognathism before and after surgical treatment. Swed Dent J 1:173, 1977 4. Witzel MA, Ross RB, Munro IR: Articulation before and after facial osteotomy. J Maxillofac Surg 8:195, 1980 5. Witzel MA: Orthognathic defects and surgical correction: The effects on speech and velopharyngeal function. Doctoral dissertation, The University of Pittsburgh, PA, 1981 6. Ruscello DM, Tekieli ME, Jakomis T, et al: The effects of orthognathic surgery on speech production. Am J Orthod 89:237, 1986 7. Turvey TA, Joumot V, Epker BN: Correction of anterior open bite deformity: A study of tongue function, speech changes, and stability. J Maxillofac Surg 4:93, 1976 8. Kummer AW, Strife JL, Grau WH, et al: The effects of Le Fort I osteotomy with maxillary movement on articulation, resonance, and velopharyngeal function. Cleft Palate J 26:193, 1989 9. Vallino LD: The effects of orthognathic surgery on speech, velopharyngeal function, and hearing. Doctoral dissertation, The University of Pittsburgh, PA, 1987 10. Dalston RM, Vig PS: Effects of orthognathic surgery on speech: A prospective study. Am J Orthod 86:291, 1984 11. Goodstein DB, Cooper D, Wallace L: The effect on speech
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12. 13. 14.
15. 16.
17.
18.
19.
20.
of surgery for correction of mandibular prognathism. Oral Surg 37:846, 1974 Witzel MA, Munro IR: Velopharyngeal insufficiency after maxillary advancement. Cleft Palate J 14:176, 1977 Schwarz C, Gruner E: Logopaedic findings following advancement of the maxilla. J Maxillofac Surg 4:40, 1976 Orentlicher GP, Sachs SA, Levy J: Long term speech and bearing changes after Le Fort I maxillary osteotomy procedures. Presented at the Combined Meeting of the American Cleft Palate Association and American Cleft Palate Educational Foundation, New York, NY, 1986 Garber SR, Speidel TM, Marse G: The effects on speech of sureical oremaxillarv osteotomv. Am J Orthod 79:54,1981 DeRuyter F, Diefenddrf AO: Hearing sensitivity and measurements of middle ear and eustachian tube function after maxillary osteotomy with advancement surgery. J Oral Surg 38:343, 1980 Baddour HM. Watson J, Erwin BJ, et al: Tympanometric changes after total maxillary osteotomy. J Oral Surg 39336, 1981 Gotzfried HF, Thumfart WE: Pre- and postoperative middle ear function and muscle activity of the soft palate after total maxillary osteotomy in cleft patients. J Craniomaxillofac Surg 1664, 1988 Fisher MA, Logemann JA: The Fisher-Logemann Test of Articulation Competence. Boston, Houghton-Mifflin, 1971 Warren DW, DuBois AB: A pressure-flow technique for
21. 22.
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24.
25.
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27.
28.
measuring velopharyngeal orifice area during continuous speech. Cfeft Palate J 1:52, 1964 Warren DW: Perci: A method for rating palatal efficiency. Cleft Palate J 16:279, 1979 Paradise JL, Smith CG, Bluestone CD: Tympanometric detection of middle ear effusion in infants and young children. Pediatrics 58: 198, 1976 Bloomer HH: Speech defects associated with dental malocclusions and related anomalies, in Travis LE (ed): Handbook of Speech Pathology and Audiology. Englewood Cliffs, NJ, Prentice Hall, 1971, p 715 Guenther TA, Sather AH. Kern EB: The effect of Le Fort I maxillary impaction on nasal airway resistance. Am J Orthod 85:388, 1984 Turvey TA, Hall DJ, Warren DW: Alterations in nasal airway resistance following superior repositioning of the maxilla. Am J Orthod 85:109, 1984 Epker BN, Wolford LM: Middle-third facial osteotomies: Their use in the correction of acquired and developmental dentofacial and craniofacial deformities. J Oral Surg 33:491, 197s Jabaley MF, Edgerton MT: Surgical correction of congenital midface retrusion in the presence of mandibular prognathism. Plast Reconstr Surg 441, 1969 McCarthy JG, Coccaro PJ, Schwartz MD: Velopharyngeal function following maxillary advancement. Plast Reconstr Surg 64: 180, 1979
J Oral Maxillofac Surg 4a:f281-1282,199O
,
wscuss/on Speech, Velopharyngeal Function, and Hearing Before and After Orthognathic Surgery Rodger
M. Dalston
School of Dentistry,
University of North Carolina, Chapel Hill
Dr Vallino provides a valuable addition to the literature concerning the impact of orthognathic surgery on communicative skills. Of particular interest are the timetables for articulation change following surgery. This information should prove useful to clinicians who must decide on the optimal time for postoperative speech intervention. Another intriguing aspect of this research is the observation that the patients with open bites tended to have fewer preoperative articulation errors than those with closed bites. It is tempting to suggest that this finding is in keeping with the observations of Warren and his colleagues’ that bite block perturbations that introduce anterior open bites as large as 6 mm do not result in aerodynamic alterations of speech. If subjects with normal occlusion are able to adapt immediately to the introduction of anterior open bites, it seems reasonable to expect that Dr Vallino’s subjects might be able to adapt fairly well to their chronic occlusal status. In light of this, it is quite interesting that Dr Vallino’s data suggest the absence of comparable adaptations among patients with closed bites. However, any suggestion that patients with open bites
may produce fewer articulation errors than patients with closed bites must be tempered by the fact that Dr Vallino does not provide enough information about her patient’s occlusal status to interpret these findings meaningfully. Although each patient presumably had a malocclusion sufficient to justify surgical intervention, that is ail we know about them. For example, we do not know the extent of the open bites or their location. We also do not know the relative position of the anterior maxillary teeth. Certainly, differences in these parameters could have a significant effect on subject performance. For example, it is conceivable that the patients with closed bites had more frequent preoperative articulation errors because of more obtrusive anterior alignment problems. Dr Vallino’s research protocol involves a useful distinction between articulations that are perceptually distorted and those that are visually obtrusive, or both. A previous study reported by Dalston and Vig’ failed to provide such a distinction and valuable information may have been lost as a consequence. Unfortunately, Dr Vallino collapses these data for the most part when discussing her results. As a consequence, the reader is unable to determine, for example, whether patients with open bites tended to have more visual distortions-as might be expected. It is my understanding that Dr Vdlino intends to present this information in a forthcoming article. Dr Vallino reports that, for the group as a whole, most errors were distortions that were “predominantly both visual and acoustic for sibilants, and visual only for tip alveolars and bilabials.” Just for purposes of claritication, no acoustic analyses were reported in the study, so
Surg
49:1274-1291.1990
Speech, Velopharyngeal Function, Hearing Before and After Orthogna thic Surgery LINDA
D. VALLINO,
and
PHD*
Articulation, voice, resonance, hearing sensitivity, and middle ear function were examined in 34 patients before and 3, 6, 9, and 12 months after orthognathic surgery. Thirty of the 34 patients had articulation errors before surgery. Errors on the sibilants /s/ and /zl occurred most frequently, followed by those on /j,zh,ch/ and lshl. Errors were predominantly distortions with both visual and acoustic components. After surgery, articulation improved spontaneously in the absence of intervention. Most of the preoperative articulation errors were eliminated by 3 months postoperative, but, thereafter, a gradual decline was noted so that by 12 months, errors occurred on /s/ and /z/. Voice, resonance, velopharyngeal port area, and hearing sensitivity were not altered by surgery. This study suggests that severe skeletal malocclusions requiring surgical correction have deleterious effects on the patients’ articulation of consonants and that surgical alteration leads to the correction of most of these errors.
Severe dental and skeletal malocclusions can have varying detrimental effects on mastication, appearance, and speech production. The treatment of such conditions generally requires both orthodontic and orthognathic surgical procedures involving the maxilla, the mandible, or both.’ The effects of orthognathic surgery on consonant articulation, the most frequently studied aspect of speech, are equivocal. Although most investigators 2-9have reported improved sound production after surgery, particularly on /s/ and lzl, otherslO~” have not concurred. Only a few studies5*‘0~‘2*‘3have
explored resonance and velopharyngeal function, both of which may be altered after advancement of the maxilla. Furthermore, the only studyI that examined voice quality showed that it did not change after surgery. Measurements of hearing sensitivity and middle ear function have received minimal attention in patients with orthognathic problems requiring correction. Although two investigations149’5 have reported no clinically significant changes in hearing thresholds after surgery, negative middle ear pressure has been documented in patients shortly after maxillary osteotomy. r6-r8 This latter condition was noted to subside within 3 to 12 weeks. The purpose of this study was to evaluate articulation, voice, resonance, velopharyngeal function, hearing sensitivity, and middle ear status before and after orthognathic surgery.
* Formerly, The University of Pittsburgh Cleft Palate and Craniofacial Center; currently, Speech-Language Pathologist/ Clinical Audiologist, Department of Speech Pathology, and Member, Craniofacial Treatment and Research Centre, The Hospital for Sick Children, Toronto, Ontario, Canada. Portions of this article were presented at the 45th Annual Meeting of the American Cleft Palate Association, Williamsburg, VA, April 1988, and at the 46th Annual Meeting of the American Cleft Palate Association, San Francisco, April 1989. This research was supported in part by Public Health Grant Number DE01697. Address correspondence and reprint requests to Dr Vallino: Department of Speech Pathology, The Hospital for Sick Children, 555 University Ave, Toronto, Ontario MSG 1X8, Canada. 0 1990 American geons
Association
of Oral and Maxillofacial
Materials and Methods SUBJECTS
Thirty-four subjects, 24 females and 10 males between the ages of 14 and 48 years (mean, 25.5; SD, 7.Q were referred to the University of Pittsburgh Cleft Palate-Craniofacial Center for examination by two maxillofacial surgeons in Pittsburgh, Pennsyl-
Sur-
0278-2391/90/4812-0006$3.00/O
1274
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LINDA D. VALLINO
vania. None of the patients had a history of cleft palate, craniofacial anomaly, or mental retardation. Ten had undergone previous speech therapy, but were not enrolled in such a program at the time of this investigation. Eleven subjects had a class II malocclusion, 12 had a class II malocclusion with an open bite, 6 had a class III malocclusion, and 5 had a class III malocclusion with an open bite. One of three types of surgical procedure was performed: the Le Fort I maxillary osteotomy, the bilateral sagittal split osteotomy, or the combined Le Fort I and bilateral sagittal split osteotomy (Table 1). Subjects were examined for speech and hearing assessments preoperatively and 3, 6, 9, and 12 months postoperatively. The first postoperative examination was conducted at 3 months because the subjects were in maxillomandibular fixation for 8 weeks after surgery. The number of postoperative assessments varied between subjects because they did not always keep appointments. CLINICAL
Speech
ASSESSMENTS
Assessment
Articulation was evaluated using the picture form of the Fisher-Logemann Test of Articulation Competence.” The number of errors was counted and the type was classified as a substitution, omission, or distortion error. Distortions were further categorized as visual, acoustic, or combined visual and acoustic (Table 2). The nature of the errors was described according to the way in which the error was made relative to the dental malocclusion and each was placed into one of seven categories (Table 3).9 Voice and Resonance
Variables of voice quality, such as breathiness, harshness, and stridency, appeared on the original rating form but none of the subjects exhibited any of these characteristics. Hence, quality was judged by the presence or absence of hoarseness; pitch was Table 1. Type of MaJocclurion and Dercrlptien of Surgical Procedures Used to Treat 34 Subjects Type of Malocclusion Type of Surgery
ClaSS II
Open Bite
Class III
Class III Open Bite
Le Fort I osteotomy Sag&al split osteotomy Combined procedures Total
0 11 0 11
3 0 9 12
0 2 4 6
1 0 4 5
ClassII
Table 2.
Definitions of Error Type
Substitution. One sound is replaced by another (eg, rat for cat). Omission. Sound is omitted from the word (eg, _at for cat). Distortion. Sound is not produced in appropriate manner but is still recognizable to the listener. Visual distortion. Appearance of the sound is abnormal but the sound itself is correct (eg, lower lip makes contact with upper teeth for bilabial sounds /p,b,m/). Auditory distortion. Perception of sound is abnormal but the appearance is correct. Combined visuallacoustic distortion. Both appearance and perception of sound are abnormal.
described as normal or abnormal. Resonance rated as hyponasal, normal, or hypernasal. Velopharyngeal
was
Port Area
Estimation of the size of the velopharyngeal port area was obtained with the pressure-flow technique described by Warren and DuBois.*’ The instrumentation and procedures have been described in detail elsewhere.20,21 Subjects were asked to repeat sentences having words containing the pressure sounds /p/ (as in puppy) and /s/ (as in sissy). These sounds were selected because they require a tight velopharyngeal seal. The single word hamper was also repeated because it contains the /-mp/ blend, which places stress on the velopharyngeal mechanism, thus closely resembling ongoing speech production.2’ Various degrees of velopharyngeal competency were determined by the pressure-flow measurements as categorized by Warren.*] An estimated area of 0 to 0.01 cm2 suggests adequate velopharyngeal closure; 0.01 to 0.015 cm*, adequate to borderline velopharyngeal closure; 0.015 to 0.02 cm2, borTable 3. Qlosury of Terms Used to Describe the Nature of Articulation Errors Frontal distortion, type I. Tongue tip is protruded between the upper and lower teeth. Frontal distortion, type II. Tongue tip is placed too far distally to the mandibular incisors while the tongue body is flattened, causing the air stream to be scattered. Denfalization. Tongue tip is placed against the superior surface of the upper or lower teeth. Lateralization. Air stream is diverted off to one or both sides of the tongue. Whistling. High-frequency sound is created by the air passing between the tongue and alveolar ridge. Mandibular movement. Mandible is positioned anteriorly or shifts laterally. Labiodentulization. Lower lip makes contact with the maxillary incisors. Data from Vallino.9
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SPEECH, VELOPHARYNGEAL
derline to inadequate velopharyngeal closure; and greater than 0.02 cm*, inadequate closure. Hearing Sensitivity Ear Function
and Middle
Hearing sensitivity was assessed with a Beltone (Chicago, IL) 200C two-channel audiometer. Both air and bone conduction thresholds were obtained. The frequencies for air conduction testing were 250, 500, 1,000, 2,000, 4,000, and 8,000 Hz bilaterally; bone conduction testing included all octave frequencies except 8,000 Hz. A Madsen impedance bridge (Model 2073; Madsen Electronics, North Tonawanda, NY) was used to determine middle ear function. Measurements of middle ear compliance, pressure, and curve gradient were obtained and classified according to the system suggested by Paradise et al.** Reliability Inter-judge reliability was established between the investigator and one other certified speech pathologist during live-speech evaluation. Agreement was 93% for articulation and 100% for voice quality, pitch, and resonance. Interjudge and intrajudge reliability for measurements of middle ear function was determined between the primary investigator and another certified audiologist. Interjudge agreement was 93% for pressure, 95% for compliance, and 93% for curve gradients. Intrajudge reliability was 95% for pressure and 97% for both compliance and curve gradients. Results SPEECH ANALYSIS
The preoperative and postoperative articulatory productions of the subjects were first analyzed as a whole group without consideration given to type of malocclusion. To compare the effects of types of malocclusion on articulation, the subjects were regrouped according to presence of closed bite or open bite. ENTIRE GROUP
Preoperatively, 30 of the 34 subjects (88.2%) had articulation errors. The number of errors ranged from 0 to 33, with a mean of 15.8 (SD, 9.1). The phonemes most frequently in error were the sibilants Is/ and /z/, followed by /j,zh,ch/ and IshI. Those least frequently involved were the tip alveolars /t,d,n/ and bilabials /p,b,m/. All errors consisted of distortions, predominantly both visual and
FUNCTION, AND HEARING
acoustic for sibilants, and visual only for tip alveolars and bilabials. Sibilant errors were characterized primarily by frontal distortions type II, followed by frontal distortions type I. All bilabial errors consisted of labiodentalizations, whereas tip-alveolar errors consisted of either dentalizations or frontal distortions type I. After surgery, 30 of the 34 subjects (88.2%) manifested a reduced number of errors in their final postoperative assessment. The data summarized in Table 4 suggest that there was a tendency for the preoperative articulation errors to improve after surgery. Subjects either eliminated their previous errors completely or, for those errors retained, reduced their number. None demonstrated a deterioration in speech production. Four subjects had no errors before or after surgery. The greatest change in articulation occurred at 3 months postoperatively, at which time the number of errors ranged from 0 to 24 with a mean of 7.3 (SD, 8.2). This was followed by a continued gradual decline in the mean number of articulation errors between 3 and 12 months. By 12 months, the number of errors ranged from 0 to 13 with a mean of 2.7 (SD, 2.3) (Fig 1). Wilcoxon’s matched-pair signed ranks test showed a statistically significant improvement in articulation at all four postoperative evaluations, as well as between the 3- and 12-month postoperative tests (P < .Ol). The percentage of phonemes produced incorrectly gradually decreased at each evaluation so that by 12 months errors remained only on /s/ and izl. At this 1Zmonth postoperative evaluation, the frequency of errors on Jsl was 20% and on lzl was 23.5%, as compared with the preoperative error percentages of 79.4 and 77.5, respectively. Bilabial errors on /p,b,m/ were completely eliminated by 3 months and tip-alveolar errors on /t,d,n/ by 6 months (Fig 2). Errors on sibilants consisted of combined visual and acoustic distortions, characterized mostly by frontal distortions type II. Table 4. Number of Subjects With Changes in Articulation Errors After Surgery Entire Group
Closed Bite
Open Bite
Preoperative Without errors With errors
4 30
1
3
16
14
Postoperative Unchanged Eliminated errors Reduced errors Deterioration
4 17 13 0
1 8 8 0
3 9 5 0
LINDA D. VALLINO
1277
oJ,
t 3 mos post op
Preop
6 mos post op
9 mos post op
12 mos post op
ASSESSMENTS
FIGURE 1.
number of articulation errors for all subjects before and after surgery. Mean
CLOSED-BITE AND OPEN-BITE GROUPS Before surgery, 16 of the 17 (98%) subjects with closed bites and 14 of the 17 (82%) subjects with open bites demonstrated articulation errors. The number of errors in the closed-bite group was larger (mean, 17.9; SD, 9.6) compared with those in the open-bite group (mean, 9.3; SD, 6.9). The errors made by subjects, irrespective of the type of malocclusion, involved 12 of the 24 phonemes tested. For both groups the phonemes most frequently in error were the sibilants Is.1 and /z/, followed by /j,zh,ch/, and /sh/. Errors on the tip alveolars /t,d,n/ and bilabials /p,b,m/ were made less often. When the nature of the sound errors was examined, sibilant errors in both groups were characterized primarily by frontal distortions type II and type I, in that order. Additional types of distortions
0
PREOP
0
POSTOP
noted during the production of the sibilant sounds by subjects with closed bites included whistling, interdentalizations, and lateral shifts of the mandible, whereas those with open bites lateralized their tongues. Regardless of the type of malocclusion, all bilabial errors were characterized by labiodentalizations, and tip-alveolar errors by dentalizations. After surgery, 16 of the 17 (94%) subjects in the closed-bite group and 14 of the 17 (82%) subjects in the open-bite group spontaneously exhibited reductions in the number of preoperative articulation errors (Table 4). Although the number of errors was reduced in both groups, the pattern of change differed. The most improvement occurred in the closed-bite group at 3 months, at which time the number of errors ranged from 0 to 17 with a mean of 5.2 (SD, 5.9), as compared with a preoperative range of 0 to 33 with a mean of 17.9 (SD, 9.6). From 3 to 9 months, the mean number of errors was essentially unchanged. At 12 months, another reduction occurred, dropping the mean number of errors further to 3.0 (SD, 5.2). In contrast, the change in the mean number of errors in the open-bite group at 3 months was minimal. The range was from 0 to 24 with a mean of 8.6 (SD, 9.3) compared with a preoperative range of 0 to 33 with a mean of 9.3 (SD, 6.9). The most notable change occurred at 6 months, followed by a gradual decline in errors to a mean of 1.5 (SD, 3.9) at 12 months, which is smaller than the mean of 3.0 (SD, 5.2) noted in the closedbite group (Fig 3). There were no statistically significant differences between the closed-bite and open-bite groups before surgery nor at 3 and 12 months after surgery. Articulation scores in the closed-bite group were consistently above the median at all three of these evaluation periods. After surgery, the percentage of involved individ-
n
Cbsed txte QrWP 0 Open bite group
01
s
j
j
ch
sh
t
n
p
b
m
PHONEMES
FIGURE 2.
of errors for individual phonemes before and 12 months after surgery for all subjects. Percentage
>
Pre op d
3 mos post op
6 mos post op
9 mos post oP
12 mos post oP
ASSESSMENTS
FIGURE 3. Meannumber of articulation errors for closed-bite and open-bite malocclusion groups before and after surgery.
1278
SPEECH, VELOPHARYNGEAL
ual phonemes decreased at each postoperative period so that by 9 months, errors were found only on /s/ and /z/ in the open-bite group. This change took as long as 12 months to occur in the closed-bite group (Fig 4). In both groups, the sibilant errors were characterized mostly by frontal distortions type II. However, the more varied speech errors in the closedbite group included errors of interdentalizations, mandibular shifting, and whistling. Subjects with open bites also exhibited dentalizations. VOICE AND RESONANCE
Before surgery, 2 of the 34 subjects, each having a closed-bite malocclusion, had hyponasality. Three months after surgery, the 24 subjects who were reevaluated all demonstrated normal resonance, including the 2 who had previously been hyponasal. Resonance did not deteriorate in any of the subjects. VELOPHARYNGEALPORT AREA
All subjects demonstrated estimated velopharyngeal port areas measuring between 0 and 0.049 cm*, indicating adequate velopharyngeal competency both before and after surgery across all speech tasks. HEARING SENSITIVITYAND MIDDLE EAR FUNCTION
Pure-tone hearing sensitivity was not adversely affected by orthognathic surgery. All subjects were considered to have normal thresholds for the speech frequencies. Middle ear compliance and curve gradient were unchanged by surgery. One subject who com-
s
z
j
zh
ch
sh
I
d
n
p
b
m
PHONEMES
FIGURE 4. Percentage of errors for individual phonemes before and 12 months after surgery for closed-bite and open-bite malocclusion groups.
FUNCTION,
AND HEARING
plained of stuffiness in the left ear 3 months after surgery demonstrated clinically significant negative middle ear pressure measurements. This individual had exhibited normal pressures bilaterally before surgery. Sudafed (pseudoephedrine, Burroughs Wellcome Inc) was prescribed, but the condition had not resolved by the end of the study. Hearing sensitivity was, however, clinically normal. Another subject, who also had normal pressure before surgery, showed bilateral negative pressures postoperatively. This condition gradually improved in the left ear to what was deemed clinically normal pressure at 12 months, but mild negative pressure persisted in the right ear. Discussion The results of this study continue to support the notion that malocclusions requiring orthognathic surgery have deleterious effects on speech. The data further show that specific types of malocclusions may influence speech more than others. As demonstrated, the mean number of preoperative errors was greater for the group of subjects who had a closed-bite malocclusion than those who had an open-bite malocclusion. This is contrary to what has been documented in the literature about the relationship between open bites and consonant defects.23 This study also supports claims that orthognathic surgery used to correct occlusal defects leads to improvement in articulation in most cases.2-9 Most of the subjects in this investigation eliminated all of their articulation errors; those who retained errors showed a reduction in their number. The four subjects who did not have preoperative errors may have learned to compensate for severe occlusal defects or may have had physical characteristics that would have explained, at least in part, their articulation patterns. Nine of 10 subjects had undergone previous speech therapy for improvement of sibilant productions, but to no avail. These findings underscore the idea that speech therapy is generally not effective in the treatment of individuals with severe malocclusions. Additionally, age did not seem to be an influencing factor in the degree of articulatory improvement. The number of subjects under 16 years was only three, making appropriate comparisons difficult. However, perusal of the data showed that two of these subjects (ages 14 and 16 years) continued to have mild sibilant errors at 12 months postoperatively. Although subjects from the closed-bite and openbite groups demonstrated improvement in articulation after surgery, it is the pattern of articulatory changes that distinguish the two groups. Improvement in the closed-bite group was greater at 3
LINDA D. VALLINO
months than in the open-bite group, but reached a plateau thereafter. In contrast, the reduction in the mean number of errors in the open-bite group was minimal at 3 months, but continued to decline over time. By 12 months, the open-bite group had fewer errors than the closed-bite group, as was the case before surgery. The subjects with closed bites appeared to have a difficult time making adjustments to a newly created oral environment that presumably would promote improved articulatory positioning. In these cases, the subjects attempted to maintain an abnormal tongue posture by varying the preoperative position of the tongue. For example, subjects demonstrating frontal distortions type II and mandibular shifting on sibilants before surgery experienced whistling or interdentalizations on these sounds after surgery. The high percentage of preoperative errors occurring on the sibilants, particularly on /s/ and /z/, suggests that these sounds are the phonemes most sensitive to variations in the oral structures. Thus, improved dental relationships promote an environment that seems to allow the tongue to assume a new posture that permits the narrow channeling of the airstream necessary for correct production of sibilants. Only distortion articulation errors were found in any of the subjects either before or after surgery. More specifically, combined visual and acoustic distortions occurred more frequently on sibilants than did isolated visual or isolated acoustic errors. That is, they looked and sounded incorrect. Visual distortions without acoustic components occurred on every error involving tip-alveolar and bilabial phonemes. Although these sounds were always judged to be acoustically correct, they were produced in a manner that looked aberrant to the observer. These visual distortions were readily eliminated by surgical correction of the malocclusion, whereas those having an acoustic component were more resistant to modification. The observation that the improvement in articulation in most of the subjects was spontaneous, without the benefit of speech therapy in the interim, seems to support the supposition that the tongue can easily make adjustments within the new oral environment. It also suggests that if a person eliminates errors, it is unlikely that these errors will recur. When the data for the entire group are analyzed, it appears that the most important time to evaluate speech is about 3 months after surgery, However, when the type of malocclusion is taken into consideration, it is clear that for some individuals, such as those with open-bite malocclusion, improvement is most noticeable 6 months after sur-
1279 gery. It is in these cases that the timing of recall for clinical examination may differ. Nonetheless, it is important to realize that in any patient, improvement may continue for as long as 1 year postoperatively. For patients who have persistent speech errors, but are stimulable for correct production, speech therapy should be recommended. Many of the errors were produced inconsistently; that is, the subjects were able to produce most sounds correctly some of the time. This ability is thought to be a positive indicator of the eventual elimination of errors with therapy. Given the different rates of spontaneous speech improvement to which specific types of malocclusion are prone, the timing of intervention may also vary. Based on this information, we may be in a better position to create programs that would maximize a patient’s learning potential. The fact that the examiner and a trained observer documented the sound productions during a live interview raises speculation about listener bias. This is certainly plausable and indicates a limitation of this investigation. The procedures Dalston and Vig” used in their study, in which preoperative and postoperative audiotape recordings of the speakers were randomly dubbed onto a master tape for listeners to rate, could have reduced this problem. However, this procedure eliminates the advantage of visualizing the way in which the individual produces the sound relative to dental structures. Although audiotape records provide a useful, permanent record of the speech sample for use in the comparison and acoustic analysis of pretreatment and posttreatment speech patterns, these recordings are limited because mild sibilant distortions may not be audible on tape, making narrow transcription of the error sound virtually impossible. The addition of videorecording helps capture the visual image but the audiosignal may still limit the assessment to traditional scoring techniques, such as noting correct or incorrect sound productions, substitutions, omissions, or distortions. Additional detailed information is critical for describing errors related to malocclusions, as well as for assessing the effect of treatment. The issue of occlusal relapse, always of concern to the maxillofacial surgeon, should also concern the speech pathologist. In those patients who retained speech errors, possible dental/skeletal relapse may have occurred. If such a condition existed, the individual would likely find it difficult to produce a correct sound, particularly the sibilant, because the oral environment would not be conducive to permitting the narrow anterior airstream necessary for its correct production. This was not
1280 tested in this study, but certainly warrants future investigation, Orthognathic defects do not appear to be associated with voice disorders, nor does orthognathic surgery affect voice quality or pitch. The findings of this study are consistent with those of Orentlicher et al.r4 Although the development of hypernasal speech after maxillary advancement is always of prime concern to both the patient and the clinician, the subjects in this study were not adversely affected. The hyponasality found in two subjects may have been the result of a blocked or partially occluded nasal airway caused by an undiagnosed condition such as edema, allergy, a cold, or some other problem. Improvement may have been due to the amelioration of a cold or allergy on the day of testing, or the altered jaw relationships may have enlarged the nasal or pharyngeal airway, thus providing a better passageway for nasal airflow, as others have observed. 10,24*25 Although investigators 12,13*26have documented hypernasality in noncleft individuals after maxillary advancement, this study substantiated the findings of other investigators5~‘0~13~27~28 who indicated that their noncleft subjects did not develop hypernasal speech after a similar procedure. Epker and Wolford26 stated that when the velopharyngeal valving mechanism is competent preoperatively, it remains unchanged postoperatively. The estimated sizes of the velopharyngeal port areas were consistent with adequate velopharyngeal competency both before and after surgery. These results are consistent with those of McCarthy et al28 and Dalston and Vig.” Although all subjects undergoing maxillary orthognathic procedures should be counseled about the possibility of alterations in velopharyngeal valving and in the resonance characteristics of speech, they can safely be assured that the risk is minimal unless borderline velopharyngeal competency is present. The latter is particularly true in those individuals with a cleft palate before surgery. Pressure-flow measurements are useful. They are advocated as a method for the routine quantification of the estimated size of the velopharyngeal port area, for the detection of those subjects at increased risk for velopharyngeal incompetency, and for the evaluation of the outcome of treatment. Visualization procedures such as videofluoroscopy and nasopharyngoscopy are also valuable adjuncts to the examination protocol. This study’s findings that pure-tone hearing sensitivity was not adversely affected by orthognathic surgery concur with those of Garber et all5 and Orentlicher et alI4
SPEECH, VELOPHARYNGEAL
FUNCTION,
AND HEARING
The number of cases in which negative middle ear pressures occurred after orthognathic surgery was small. Perhaps surgery induces a mechanical dysfunction of the eustachian tube because of swelling or perhaps it exacerbates a preexisting problem. Because anesthesia is administered through nasotracheal intubation, it is possible that changes in middle ear pressure in one ear may be the result of prolonged intubation on that side, thus causing a temporary obstruction of the eustachian tube.‘“18 Prolonged maxillomandibular fixation may impair adequate ventilation of the middle ear and eustachian tube, the effects of which have not been thoroughly investigated. Much more exploratory work is required in this area, including presurgical and postsurgical evaluation of eustachian tube function, as well as intraoperative testing. Audiologic assessment should be conducted before and after surgery. Tympanometric evaluations are valuable when the maxilla is being repositioned. When negative middle ear pressure persists after surgery, eustachian tube function tests should be considered. Acknowledgment The author would like to thank Drs Betty Jane McWilliams, John Pierce, Joseph Andrews, and Mark Previtt for their assistance during this study. This article was prepared with the assistance of Medical Publications, The Hospital for Sick Children, Toronto.
References 1. Bell WH (ed): Surgical Correction of Dentofacial Deformities. vol 3. Philadelnhia. PA. Saunders. 1985 2. Glass L, Knapp J, Bloomer HH: Speech and lingual behavior before and after mandibular osteotomy. J Oral Surg 35: 104, 1977 3. Weimer K, Astrand P: Effect on speech of mandibular prognathism before and after surgical treatment. Swed Dent J 1:173, 1977 4. Witzel MA, Ross RB, Munro IR: Articulation before and after facial osteotomy. J Maxillofac Surg 8:195, 1980 5. Witzel MA: Orthognathic defects and surgical correction: The effects on speech and velopharyngeal function. Doctoral dissertation, The University of Pittsburgh, PA, 1981 6. Ruscello DM, Tekieli ME, Jakomis T, et al: The effects of orthognathic surgery on speech production. Am J Orthod 89:237, 1986 7. Turvey TA, Joumot V, Epker BN: Correction of anterior open bite deformity: A study of tongue function, speech changes, and stability. J Maxillofac Surg 4:93, 1976 8. Kummer AW, Strife JL, Grau WH, et al: The effects of Le Fort I osteotomy with maxillary movement on articulation, resonance, and velopharyngeal function. Cleft Palate J 26:193, 1989 9. Vallino LD: The effects of orthognathic surgery on speech, velopharyngeal function, and hearing. Doctoral dissertation, The University of Pittsburgh, PA, 1987 10. Dalston RM, Vig PS: Effects of orthognathic surgery on speech: A prospective study. Am J Orthod 86:291, 1984 11. Goodstein DB, Cooper D, Wallace L: The effect on speech
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12. 13. 14.
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of surgery for correction of mandibular prognathism. Oral Surg 37:846, 1974 Witzel MA, Munro IR: Velopharyngeal insufficiency after maxillary advancement. Cleft Palate J 14:176, 1977 Schwarz C, Gruner E: Logopaedic findings following advancement of the maxilla. J Maxillofac Surg 4:40, 1976 Orentlicher GP, Sachs SA, Levy J: Long term speech and bearing changes after Le Fort I maxillary osteotomy procedures. Presented at the Combined Meeting of the American Cleft Palate Association and American Cleft Palate Educational Foundation, New York, NY, 1986 Garber SR, Speidel TM, Marse G: The effects on speech of sureical oremaxillarv osteotomv. Am J Orthod 79:54,1981 DeRuyter F, Diefenddrf AO: Hearing sensitivity and measurements of middle ear and eustachian tube function after maxillary osteotomy with advancement surgery. J Oral Surg 38:343, 1980 Baddour HM. Watson J, Erwin BJ, et al: Tympanometric changes after total maxillary osteotomy. J Oral Surg 39336, 1981 Gotzfried HF, Thumfart WE: Pre- and postoperative middle ear function and muscle activity of the soft palate after total maxillary osteotomy in cleft patients. J Craniomaxillofac Surg 1664, 1988 Fisher MA, Logemann JA: The Fisher-Logemann Test of Articulation Competence. Boston, Houghton-Mifflin, 1971 Warren DW, DuBois AB: A pressure-flow technique for
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measuring velopharyngeal orifice area during continuous speech. Cfeft Palate J 1:52, 1964 Warren DW: Perci: A method for rating palatal efficiency. Cleft Palate J 16:279, 1979 Paradise JL, Smith CG, Bluestone CD: Tympanometric detection of middle ear effusion in infants and young children. Pediatrics 58: 198, 1976 Bloomer HH: Speech defects associated with dental malocclusions and related anomalies, in Travis LE (ed): Handbook of Speech Pathology and Audiology. Englewood Cliffs, NJ, Prentice Hall, 1971, p 715 Guenther TA, Sather AH. Kern EB: The effect of Le Fort I maxillary impaction on nasal airway resistance. Am J Orthod 85:388, 1984 Turvey TA, Hall DJ, Warren DW: Alterations in nasal airway resistance following superior repositioning of the maxilla. Am J Orthod 85:109, 1984 Epker BN, Wolford LM: Middle-third facial osteotomies: Their use in the correction of acquired and developmental dentofacial and craniofacial deformities. J Oral Surg 33:491, 197s Jabaley MF, Edgerton MT: Surgical correction of congenital midface retrusion in the presence of mandibular prognathism. Plast Reconstr Surg 441, 1969 McCarthy JG, Coccaro PJ, Schwartz MD: Velopharyngeal function following maxillary advancement. Plast Reconstr Surg 64: 180, 1979
J Oral Maxillofac Surg 4a:f281-1282,199O
,
wscuss/on Speech, Velopharyngeal Function, and Hearing Before and After Orthognathic Surgery Rodger
M. Dalston
School of Dentistry,
University of North Carolina, Chapel Hill
Dr Vallino provides a valuable addition to the literature concerning the impact of orthognathic surgery on communicative skills. Of particular interest are the timetables for articulation change following surgery. This information should prove useful to clinicians who must decide on the optimal time for postoperative speech intervention. Another intriguing aspect of this research is the observation that the patients with open bites tended to have fewer preoperative articulation errors than those with closed bites. It is tempting to suggest that this finding is in keeping with the observations of Warren and his colleagues’ that bite block perturbations that introduce anterior open bites as large as 6 mm do not result in aerodynamic alterations of speech. If subjects with normal occlusion are able to adapt immediately to the introduction of anterior open bites, it seems reasonable to expect that Dr Vallino’s subjects might be able to adapt fairly well to their chronic occlusal status. In light of this, it is quite interesting that Dr Vallino’s data suggest the absence of comparable adaptations among patients with closed bites. However, any suggestion that patients with open bites
may produce fewer articulation errors than patients with closed bites must be tempered by the fact that Dr Vallino does not provide enough information about her patient’s occlusal status to interpret these findings meaningfully. Although each patient presumably had a malocclusion sufficient to justify surgical intervention, that is ail we know about them. For example, we do not know the extent of the open bites or their location. We also do not know the relative position of the anterior maxillary teeth. Certainly, differences in these parameters could have a significant effect on subject performance. For example, it is conceivable that the patients with closed bites had more frequent preoperative articulation errors because of more obtrusive anterior alignment problems. Dr Vallino’s research protocol involves a useful distinction between articulations that are perceptually distorted and those that are visually obtrusive, or both. A previous study reported by Dalston and Vig’ failed to provide such a distinction and valuable information may have been lost as a consequence. Unfortunately, Dr Vallino collapses these data for the most part when discussing her results. As a consequence, the reader is unable to determine, for example, whether patients with open bites tended to have more visual distortions-as might be expected. It is my understanding that Dr Vdlino intends to present this information in a forthcoming article. Dr Vallino reports that, for the group as a whole, most errors were distortions that were “predominantly both visual and acoustic for sibilants, and visual only for tip alveolars and bilabials.” Just for purposes of claritication, no acoustic analyses were reported in the study, so
