- Email: [email protected]
The effects on speech of surgical premaxillary osteotomy
The effects on speech of surgical premaxillary osteotomy Sharon FL Garber, Ph.D.,* T. Michael Speidel, D.D.S., M.S.D.,** and George Marse, D.D.S., M.S. Pittsburgh,
Pa.,
Patients
Minneapolis,
were
tested
Minn.,
before
and New
and
after
Orleans,
undergoing
La.
surgical
premaxillary
(1 / eotomy
for
correction of skeletal and soft-tissue discrepancies. Both structural and 5 wd7 measurements were made before surgery and for a year after surgery. 7‘1,~ role of hearing and oral sensation in adaptation to surgety was evaluated. Immc C,l’iately after surgery, speech was disrupted. Distortions of lsl predominated. Howevr>,., there were no long-term effects on speech. Hearing and oral sensation played little :ole in adaptation
Key words: Speech, surgery, osteotomy, hearing, adaptation
S
evere skeletal discrepancies often result in abnormal occlusal patterns and soft-tissue disproportion and can interfere with function. In recent years, the development and refinement of orthognathic surgical procedures has advanced the treatment of such discrepancies.’ Recent studies have documented the effects of surgery on hard and soft tissues.** 3 However, the effects of surgery on function have received minimal attention. One aspect of function that is of potential significance is speech. The few studies which have been conducted to assess the effects of orthognathic surgery on speech have been equivocal.4-s For example, Goodstein, Cooper, and Wallace5 and Wahoske6 report no changes in speech following surgery. Turvey, Joumot, and Epker7 found that speech improved in five patients and deteriorated in one after surgery. Glass, Knapp, and Bloomer* indicate that the speech of all patients improved after surgery. Most likely, the discrepant results are because of the inclusion of two or more different surgical procedures in the same study, the small number of patients tested, the varying techniques used to assess speech, and the inclusion of some patients who present with normal speech and others who present with speech difficulties. The purpose of the present study is to assess the effects of surgical premaxillary osteotomy on the speech of a relatively homogeneous group of patients. In order to interpret these effects better, we included a variety of speech tasks and analyses. In This research was supported by National Institute of Dental Research 05002-01 and by grants awarded to the Center for Research in Human *Department of Speech and Theatre Arts, University of Pittsburgh. **University of Minnesota School of Dentistry.
54
0002.9416/81/010054+09$00.90/0
Fellowship No. 1 F32 DE Learning, Minneapolis.
0
1981 The
C.
V. Mosby
Co.
vohme
79
Number
1
Effects
of speech on surgicul premaxillary osteotomy 55
addition, the role of oral sensation and hearing in adaptation to surgery was assessed. The results of this study should have theoretical implications about the relationship between structure and function and clinical implications for persons involved in the treatment of surgery patients. Methods and materials Patients. The sample included five female patients and one male patient, ranging in age from 14 to 24 years, with a mean age of 21 years at the time of treatment. All patients initially demonstrated severe maxillary prognathism with varying degrees of vertical skeletal disproportion. The mean ANB angle of the group was 6.2 degrees, with a range of 5.0 to 9.5 degrees. All patients passed a hearing screening test in both ears at 20 dB HL (ANSI-1969) at 500, 1,000, 2,000, and 4,000 Hz. None of the patients had concerns about their speech at the time of surgery. No neurologic impairment or facial paralysis was noted. Patients did not receive speech therapy during the course of the study. Treatment. All patients underwent a premaxillary setback osteotomy in conjunction with orthodontic treatment. The anterior maxillary segment of teeth and supporting structures was surgically freed and repositioned in a translatory manner into the space created by extraction of the premolars. The segment was fixated for approximately 4 weeks with an acrylic splint, an arch wire, or both. Pre- and postsurgery orthodontic treatment prepared the dental arches for surgery, facilitated fixation, and expedited the final interdigitation of the teeth. Length of total treatment ranged from 10 months to 2 years 5 months, with a mean of 1 year 7 months. All surgical procedures were performed by members of the Department of Oral Surgery at the University of Minnesota School of Dentistry. Orthodontic treatment was provided by the Department of Orthodontics. Structural measurements. Overbite and overjet changes were measured directly from standard orthodontic casts which were made before and after treatment. Hard- and softtissue changes were measured from standard cephalometric films taken before treatment (prior to orthodontic banding and extractions), immediately before surgery, and after treatment (following removal of orthodontic bands). The average time between surgery and the final x-ray was 8.6 months. Skeletal tissue changes were assessed using measurements adapted from Reidel’s analysis. Changes in soft tissue were assessedby measurements adapted for the Minnesota Soft Tissue Analysis.3* g Speech measurements. DATA COLLECTION. Patients were tape recorded immediately before surgery (within 2 days), immediately after surgery (5 to 7 days after surgery), and 1 month, 3 months, 6 months, and 1 year after splint removal. Splints were removed 2 to 4 weeks after surgery. One patient wore no splint. Patients were recorded while performing several speech tasks in quiet and while listening to a 90 dB SPL speech noise. Noise was included to assessthe role of hearing in adaptation to surgery. Previous work suggests that persons with poorly developed speech skills have difficulty speaking in the presence of noise.‘O If hearing is important in adaptation to surgery, speech should deteriorate in the presence of noise, parh&rly in the postsurgical testing periods. The speech tasks consisted of reading a word list, a list of sentences, and a standard
56
Garber,
Speidel,
and
Marx
Am. .I. Orthod. Januan,
1981
reading passage, “Arthur the young rat. ” The word and sentence lists were loaded with phonemes produced in the anterior portion of the oral cavity. In each testing period, patients also were asked to speak spontaneously for 1 minute. Tapes were made with the patient seated in a sound-treated room (Ray Proof A16-134, Norwalk, Conn.) approximately 20 cm. from a microphone (Electra Voice 674, Buchanan, Mich.). The output of the microphone fed a mixer (Ampex Am 10, Redwood City, Calif.) for amplification. The mixer fed a tape recorder (Scully 280 B, Mountain View, Calif.). During noise conditions, the noise was produced by a speech audiometer (Grason Stadler 1701, Concord, Mass.) and fed a pair of headphones (Grason Stadler TDH-49 earphones with MX 4 1/AR cushions, Concord, Mass .). The noise was presented at 90 dB SPL (re: 0.0002 pupa) as measured at the level of the headphones with a sound level meter (General Radio 1933, Concord, Mass.) and an earphone coupler (General Radio 1560-P83, Concord, Mass .) DATA ANALYSIS. The words, sentences, and reading passage were analyzed independently by two speech pathologists who were naive about the purpose of the study. Each speech pathologist sat alone in a sound-treated room and listened to the tapes. Each evaluated the tapes for omissions, additions, substitutions, or distortions and marked any error on sheets containing transcriptions of the speech materials. An experimenter compared the transcriptions of each observer. An error was defined as a phoneme on which both observers agreed that an error had occurred. In cases where both observers agreed that an error had occurred but disagreed about the type of error, the error was classified as a “combination” error. The number of errors, type of errors, and phonemes in error were recorded for each subject and condition. The spontaneous speech task was included to determine, in general, how normal the subjects sounded under each condition. A substudy was run to evaluate the spontaneous speech data. In this study, a group of twelve college students were asked to evaluate the speech samples. A master tape of the spontaneous speech data was made by dubbing two IS-second samples of each patient and condition in random order onto a new tape. Samples were recorded at equal intensity levels and were played to the listeners at 75 dB SPL. Each listener was seated alone in a sound-treated room and heard the samples through the headphones. Listeners were asked to rate each 15second sample for “normalcy” using a l- 10 equal-appearing-interval scale where 1 indicated that the speech sounded completely normal and 10 indicated that the speech sounded very abnormal. Ratings of each patient and condition were averaged across listeners and across the two samples which had been selected for each condition. Measurement of oral sensory function. An oral form discrimination task was used to assessthe role of oral sensation in adaptation to surgery. Patients performed the oral form discrimination task immediately before surgery and 1 month, 3 months, 6 months, and 1 year after splint removal. The forms and procedures were the same as those reported by Ringel, Burk, and Scott. l1 Briefly, the patient was blindfolded and the experimenter presented the forms to the patient in pairs. The patient’s task was to explore two forms orally in succession and to determine whether the forms were the same or different. A total of ten practice trials and fifty-five test pairs were presented. The pairs were presented in a different random order during each testing period.
Volume 79 Number 1
Table
Effects
of speech
on surgical
premaxillary
osteotomy
57
I. Structural changes
Selected
hard-
and soft-tissue
measurements
Overjet Overbite ANB Upper central incisor: Sella-nasion Upper central incisor tip: Upper lip Nasolabial angle Inferior labial sulcus angle Superior labial sulcus: Subnasale-pogonion Inferior labial sulcus: Subnasale-pogonion Superior vermilion border: Subnasale-pogonion Inferior vermilion border: Subnasale-pogonion Lip opening
Mean
change
Range
of change
-6.0 mm. -1.0 mm. -4.1” +0.75” -2.33 mm. +8.9” +21.75” +1.9 mm. +o. 15 mm.
-7.0 to -5.0 mm. -2.0 to 0.0 mm. -5.5” to -2.0” -7” to +3” -5.5 to -1.5 mm. +3.5” to + 14.0” +10.5” to +52.0” f0.5 to +4.0 mm. -1.5 to +l.Omm.
+3.3
mm.
+ I .O to +5.0
mm.
+1.5 -4.16
mm. mm.
0.0 to +3.5 -7.5 to -2.0
mm. mm.
Results
Table I illustrates the means and ranges of selected hard- and soft-tissue measurements from dental casts and cephalometric x-ray films. Measurements of five dental casts were made twice to assessintraexaminer reliability. The average difference between the first and second measurements was 0.25 mm. with a range of 0.0 to 0.5 mm. On the dental casts, all patients exhibited a posterior repositioning of the upper teeth relative to the lower teeth as indicated by the mean decrease in overjet of 6.0 mm. with a range of 5.9 mm. to 7.0 mm. Vertical relationships of the upper and lower incisors were also changed. In five patients the overbite decreased, and in one it remained the same. The molar relationship remained the same in all patients, indicating very little change in the posterior dentition. The canine relationship, however, did change in all patients from Class II to Class I. Cephalometric data from one randomly selected patient were evaluated twice to assess intraexaminer reliability. The mean difference between the first and second angular measurements was 0.35 degrees, with a range of 0 to 2.0 degrees. The mean difference between the first and second linear measurements was 0.4 mm., with a range of 0 to 1.0 mm. On the x-rays, all patients exhibited a posterior repositioning of the premaxilla relative to the cranial base. The premaxilla was also posteriorly repositioned relative to the mandible. Very little change was observed in the mandible. Soft-tissue changes also were noted following surgery. The superior labial sulcus, superior vermilion border, inferior vermilion border, and inferior labial sulcus all were posteriorly repositioned. The nasolabial angle and inferior labial sulcus angle increased. Degree of lip opening decreased. Speech
measurements.
TASKS. Data for similar. Therefore, data will reliability of speech analyses data for eight conditions two READING
the word list, sentence list, and reading passage were quite be presented only for the reading passage. Intraexaminer was made by asking each speech pathologist to analyze the times. A Pearson Product Moment Correlation Coefficient
58
Garber,
Am. J. Orthod. Janua~ 1981
Speidel, and Marse 70 -
*Noise 60-
O-Quiet
250
-
0
k W40z z30E z20
-
IX 10 I
1
pre -
I
postSurgery
Fig. 1. The immediately
mean number after surgery,
I
1 mo.
Testing
i
3 mo.
1
6 mo.
I
1 yr.
Periods
of speech errors produced on the reading passage and 1 month, 3 months, 6 months, and 1 year after
task before splint removal.
surgery,
was computed for the number of errors counted by each observer during the first and second trials for each condition. The correlations for both Examiners 1 and 2 were 0.99. Fig. 1 displays the mean number of errors produced by patients before surgery, immediately after surgery, and 1 month, 3 months, 6 months, and 1 year after splint removal. The mean number of errors produced in quiet are represented by open circles, noise by closed circles. Immediately after surgery, the number of errors increased. By 1 month after splint removal, the number of errors was at presurgery levels. More errors were noted in noise than in quiet. However, there was no interaction between time periods and listening conditions. A two-factor repeated-measures analysis of variance was computed on the data. l2 The differences between times (presurgery, immediately postsurgery, etc.) were significant [F(2,10) = 10.67; p < .Ol] and the difference between listening conditions (noise versus quiet) was significant [F(1,5) = 32.72; p < .Ol]. The interaction between time periods and listening conditions was not significant (p > 0.05). Individual data revealed that five of six patients were at the presurgery level for number of errors by one month following splint removal. The one remaining patient reached the presurgery level within 3 months. At all time periods the majority of errors were distortions. Immediately after surgery, the increase in errors was accounted for by a disproportionate increase in distortions. The relative number of distortions returned to presurgery levels 1 month after splint removal. A chi-square test on distribution of errors at the different testing periods proved to be significant [X2(6) = 20.79; p < .Ol]. The distribution of phonemes most frequently in error was calculated. Immediately after surgery there was a disproportionate number of errors produced on Is/. Errors on Is/ returned to presurgery levels within 1 month after splint removal. Spontaneous speech task. The “normalcy” ratings for the spontaneous speech task are
Volume 79 Number
Effects
1
of speech
on surgical
premaxillay
59
osteotomy
O-Noise 6-
fGiuiet
5P ‘g 4 K
IX lY I
I
preSurgery Fig. 2. The mean speech evaluated the spontaneous
I
post-
rating assigned speech task.
I 3 mo.
1 mo. Testing
I 6 mo.
Periods
to patients
at different
testing
periods
by listeners
who
10r
g6
“1
c
2 w42-
Fig. 3. The mean
number
I
I
pre -
postSurgery
of errors
produced
I
1 mo. Testing
I 3 mo.
I 6 mo
I 1 yr.
Periods
on the oral form
discrimination
task in each
testing
period.
presented in Fig. 2. Ratings are on the ordinate, and time intervals are on the abscissa. Quiet conditions are represented by open circles, noise by closed circles. The average rating assigned to patients increased immediately after surgery but decreased to the presurgery level one month following splint removal. A slight drop in the ratings was noted at later testing periods. A higher rating was assigned in noise than in quiet but there was no interaction between the time intervals and listening conditions. A two-factor repeated-measures analysis of variance was computed on the data. The differences between times were significant [F(3,15) = 12.31; p < .OOl], and the differences between listening conditions were significant [F(1,5) = 6.61; p < .05]. The interaction between listening conditions and time was not significant. Individual data revealed that two patients returned to their presurgery ratings 1 month after splint removal. Three returned 3 months after splint removal, and one returned 6 months after splint removal. Oral form discrimination. The mean number of errors made by patients in the oral form discrimination test is illustrated in Fig. 3. Few errors were made during any of the
60
Gurber,
Speidel,
und Marse
Am. 1. Orthod. January 1981
test periods. The difference in errors across test periods was not significant (p > 0.05). No discernible pattern was seen in individual patients across testing periods. Discussion Structural changes. The structural changes measured following surgery consisted of a reduction in overjet due to the posterior repositioning of the premaxilla. In addition, posterior repositioning of corresponding soft tissues was noted. These changes are unremarkable and are similar to those reported by Kotteman.3 Only limited evaluations of lip competence can be made on the basis of these measurements. Yet, a common motivating factor for persons who seek orthognathic surgery is the complaint that they cannot close their lips comfortably at rest. On the basis of clinical judgments, no patient could achieve lip closure without some muscular strain prior to treatment. Clinical judgments made after surgery suggested a more relaxed facial countenance with increased ease of lip approximation at rest. These clinical judgments, as well as changes in lip posture revealed by evaluation of cephalometric x-rays, are consistent with the treatment objectives for the group. That is, it appears that patients can close their lips at rest more comfortably after surgery than before. However, it is important to note that there was a large individual variability among subjects. When asked to assume a resting posture for the presurgical cephalometric x-ray film, all six patients had their lips apart. Three of the six patients had their lips together in the posttreatment x-ray films, but three did not. Speech measurements. Speech deteriorated immediately following surgery. These effects may be due at least in part to the presence of the splint. Previous research indicates that orthodontic retainers which are similar to splints induce speech difficulties.‘3, I4 It is impossible to separate the effects of the splint from the effects of the surgery. However, it is interesting to note that Patient 3, who did not wear a splint, evidenced a speech disruption immediately after surgery. Orthodontic banding also may have influenced speech. l5 Because of time constraints, patients in the present study were not tested prior to banding. It would be useful in the future to test patients before and after banding as well as before and after surgery. Yet another variable which may be affecting speech is postsurgical swelling. Although most swelling had subsided by one week following surgery, some may have remained. It should be noted that a few speech errors were present during the reading task prior to surgery. Most likely this does not reflect a speech disorder on the part of the patients but, rather, reflects the fact that analyses were made from tape recordings instead of live and that raters were asked to make very fine discriminations. Thus, speech differences that were noted prior to surgery probably were not clinically significant. Recovery from surgery was a bit slower for spontaneous speech than for the reading tasks. Only two patients returned to their presurgery ratings 1 month after surgery. Three returned by 3 months and one by 6 months. Because one must formulate a message, spontaneous speech is a more stressful task than reading. Thus, it is not surprising that recovery was slower. The speech data indicate that premaxillary-setback patients are able to adapt quite well to surgery. Although the patients evidence speech disruptions immediately after surgery, there were no apparent long-term effects. In addition, the speech disruptions which did
Volume 79 Number 1
Effects of speech on surgical premaxillary
osteotomy
61
occur were not large. Immediately after surgery, naive listeners rated the patients’ speech as being moderately abnormal. Errors which occurred were mainly distortions. That is, patients generally were producing the appropriate phonemes but were producing them incorrectly. Hearing and oral sensory skills had little effect on adaptation to surgery. More speech errors were noted in noise than in quiet, but the relationship between noise and quiet was the same before and after surgery. There was no discernible change in oral sensory function following surgery. Relationship of structures and speech. Speech errors were noted immediately after surgery. What accounts for these errors ? By what process do patients adapt to the changes? An attempt was made to answer these questions by videotaping patients before and after surgery. It was hoped that assessment of lip and jaw movements during speech before and after surgery would help to delineate modes of adaptation. Unfortunately, it was very difficult to measure lip and jaw movements accurately from the videotapes. Thus, results were not reported. However, two very interesting patterns emerged. First, in function, the amount of visible incisor noted did not change following surgery. That is, the improvement in lip competence evident in cephalometric measurements at rest was not evident during function. Second, prior to surgery some patients displayed a pattern of forward mandibular movement during speech. This pattern sometimes continued following surgery. After surgery, the forward movement carried the lower incisors anterior to the upper incisors, which resulted in speech distortions. In order to document these intriguing observations, a videofluoroscopic examination of patients before and after surgery is planned. Tongue function also will be evaluated using the videofluoroscopic procedure. The tongue plays an active and important role in adaptation. Unfortunately, it is difficult to measure the tongue accurately with most procedures. It is hoped that measurements will be obtainable with the videofluoroscopic technique. REFERENCES 1. Lines, P. A., and Steinhauser, E. W.: Diagnosis and treatment planning in surgical orthodontic therapy, AM. J. ORTHOD. 66: 378-397, 1974. 2. Worms, F. W., Isaacson, R. J., and Speidel, T. M.: Surgical orthodontic treatment planning: Profile analysis and mandibular surgery, Angle Orthod. 46: l-25, 1976. 3. Kotteman, W. .I.: Mid-facial profile changes associated with maxillary subapical osteotomy, unpublished M.S.D. thesis, University of Minnesota, 1978. 4. Hershman, D. S., Tinsley, G. L., and Schow, C. E.: Apertognathia-An interdisciplinary approach: Report of case, J. Oral Surg. 30: 743-747, 1972. 5. Goodstein, B. A., Cooper, D., and Wallace, L.: The effect on speech of surgery for correction of mandibular prognathism, Oral Surg. 37: 846-849, 1974. 6. Wahoske, P.: The effects of surgically altering oral cavity relationships on speech production, Master’s thesis, University of Minnesota, 1975. 7. Turvey, T. A., Joumot, V., and Epker, B. N.: Correction of anterior open bite deformity: A study of tongue function, speech changes, and stability, J. Maxillofac. Surg. 4: 93-101, 1976. 8. Glass, L., Knapp, J., and Bloomer, H. H.: Speech and lingual behavior before and after mandibular osteotomy, J. Oral Surg. 35: 104-109, 1977. 9. Speidel, T. M., Marine, K., and Worms, F.: Soft tissue changes associated with mandibular subapical osteotomy, Angle Orthod. 49: 56-64, 1979. 10. Manning, W., Keappock, N., and Stick, S.: The use of auditory masking to estimate automatization of correct articulatory production, J. Speech Hear. Disord. 41: 143-149, 1976.
62
Garber,
Speidel, and Marse
Am. J. Orihod. January 1981
11. Ringel, R. L., Burk, K. W., and Scott, C. M.: Tactile perception: Form discrimination in the mouth, Br. J. Commun. Dis. 3: 150-15.5, 1968. 12. Winer, B.: Statistical principles in experimental design, New York, 1971, McGraw-Hill Book Company. 13. Erb, D. P.: Speech effects of the maxillary retainer, Angle Orthod. 37: 298-303, 1967. 14. Garber, S., Speidel, T. M., Siegel, G., Miller, E., and Glass, L.: The effects of presentation of noise and dental appliances on speech, J. Speech Hear. Res. (In press.) 15. Feldman, E. W.: Speech articulation problems associated with placement of orthodontic appliances, J. Speech Hear. Disord. 21: 34-38, 1956.
Pa.,
Patients
Minneapolis,
were
tested
Minn.,
before
and New
and
after
Orleans,
undergoing
La.
surgical
premaxillary
(1 / eotomy
for
correction of skeletal and soft-tissue discrepancies. Both structural and 5 wd7 measurements were made before surgery and for a year after surgery. 7‘1,~ role of hearing and oral sensation in adaptation to surgety was evaluated. Immc C,l’iately after surgery, speech was disrupted. Distortions of lsl predominated. Howevr>,., there were no long-term effects on speech. Hearing and oral sensation played little :ole in adaptation
Key words: Speech, surgery, osteotomy, hearing, adaptation
S
evere skeletal discrepancies often result in abnormal occlusal patterns and soft-tissue disproportion and can interfere with function. In recent years, the development and refinement of orthognathic surgical procedures has advanced the treatment of such discrepancies.’ Recent studies have documented the effects of surgery on hard and soft tissues.** 3 However, the effects of surgery on function have received minimal attention. One aspect of function that is of potential significance is speech. The few studies which have been conducted to assess the effects of orthognathic surgery on speech have been equivocal.4-s For example, Goodstein, Cooper, and Wallace5 and Wahoske6 report no changes in speech following surgery. Turvey, Joumot, and Epker7 found that speech improved in five patients and deteriorated in one after surgery. Glass, Knapp, and Bloomer* indicate that the speech of all patients improved after surgery. Most likely, the discrepant results are because of the inclusion of two or more different surgical procedures in the same study, the small number of patients tested, the varying techniques used to assess speech, and the inclusion of some patients who present with normal speech and others who present with speech difficulties. The purpose of the present study is to assess the effects of surgical premaxillary osteotomy on the speech of a relatively homogeneous group of patients. In order to interpret these effects better, we included a variety of speech tasks and analyses. In This research was supported by National Institute of Dental Research 05002-01 and by grants awarded to the Center for Research in Human *Department of Speech and Theatre Arts, University of Pittsburgh. **University of Minnesota School of Dentistry.
54
0002.9416/81/010054+09$00.90/0
Fellowship No. 1 F32 DE Learning, Minneapolis.
0
1981 The
C.
V. Mosby
Co.
vohme
79
Number
1
Effects
of speech on surgicul premaxillary osteotomy 55
addition, the role of oral sensation and hearing in adaptation to surgery was assessed. The results of this study should have theoretical implications about the relationship between structure and function and clinical implications for persons involved in the treatment of surgery patients. Methods and materials Patients. The sample included five female patients and one male patient, ranging in age from 14 to 24 years, with a mean age of 21 years at the time of treatment. All patients initially demonstrated severe maxillary prognathism with varying degrees of vertical skeletal disproportion. The mean ANB angle of the group was 6.2 degrees, with a range of 5.0 to 9.5 degrees. All patients passed a hearing screening test in both ears at 20 dB HL (ANSI-1969) at 500, 1,000, 2,000, and 4,000 Hz. None of the patients had concerns about their speech at the time of surgery. No neurologic impairment or facial paralysis was noted. Patients did not receive speech therapy during the course of the study. Treatment. All patients underwent a premaxillary setback osteotomy in conjunction with orthodontic treatment. The anterior maxillary segment of teeth and supporting structures was surgically freed and repositioned in a translatory manner into the space created by extraction of the premolars. The segment was fixated for approximately 4 weeks with an acrylic splint, an arch wire, or both. Pre- and postsurgery orthodontic treatment prepared the dental arches for surgery, facilitated fixation, and expedited the final interdigitation of the teeth. Length of total treatment ranged from 10 months to 2 years 5 months, with a mean of 1 year 7 months. All surgical procedures were performed by members of the Department of Oral Surgery at the University of Minnesota School of Dentistry. Orthodontic treatment was provided by the Department of Orthodontics. Structural measurements. Overbite and overjet changes were measured directly from standard orthodontic casts which were made before and after treatment. Hard- and softtissue changes were measured from standard cephalometric films taken before treatment (prior to orthodontic banding and extractions), immediately before surgery, and after treatment (following removal of orthodontic bands). The average time between surgery and the final x-ray was 8.6 months. Skeletal tissue changes were assessed using measurements adapted from Reidel’s analysis. Changes in soft tissue were assessedby measurements adapted for the Minnesota Soft Tissue Analysis.3* g Speech measurements. DATA COLLECTION. Patients were tape recorded immediately before surgery (within 2 days), immediately after surgery (5 to 7 days after surgery), and 1 month, 3 months, 6 months, and 1 year after splint removal. Splints were removed 2 to 4 weeks after surgery. One patient wore no splint. Patients were recorded while performing several speech tasks in quiet and while listening to a 90 dB SPL speech noise. Noise was included to assessthe role of hearing in adaptation to surgery. Previous work suggests that persons with poorly developed speech skills have difficulty speaking in the presence of noise.‘O If hearing is important in adaptation to surgery, speech should deteriorate in the presence of noise, parh&rly in the postsurgical testing periods. The speech tasks consisted of reading a word list, a list of sentences, and a standard
56
Garber,
Speidel,
and
Marx
Am. .I. Orthod. Januan,
1981
reading passage, “Arthur the young rat. ” The word and sentence lists were loaded with phonemes produced in the anterior portion of the oral cavity. In each testing period, patients also were asked to speak spontaneously for 1 minute. Tapes were made with the patient seated in a sound-treated room (Ray Proof A16-134, Norwalk, Conn.) approximately 20 cm. from a microphone (Electra Voice 674, Buchanan, Mich.). The output of the microphone fed a mixer (Ampex Am 10, Redwood City, Calif.) for amplification. The mixer fed a tape recorder (Scully 280 B, Mountain View, Calif.). During noise conditions, the noise was produced by a speech audiometer (Grason Stadler 1701, Concord, Mass.) and fed a pair of headphones (Grason Stadler TDH-49 earphones with MX 4 1/AR cushions, Concord, Mass .). The noise was presented at 90 dB SPL (re: 0.0002 pupa) as measured at the level of the headphones with a sound level meter (General Radio 1933, Concord, Mass.) and an earphone coupler (General Radio 1560-P83, Concord, Mass .) DATA ANALYSIS. The words, sentences, and reading passage were analyzed independently by two speech pathologists who were naive about the purpose of the study. Each speech pathologist sat alone in a sound-treated room and listened to the tapes. Each evaluated the tapes for omissions, additions, substitutions, or distortions and marked any error on sheets containing transcriptions of the speech materials. An experimenter compared the transcriptions of each observer. An error was defined as a phoneme on which both observers agreed that an error had occurred. In cases where both observers agreed that an error had occurred but disagreed about the type of error, the error was classified as a “combination” error. The number of errors, type of errors, and phonemes in error were recorded for each subject and condition. The spontaneous speech task was included to determine, in general, how normal the subjects sounded under each condition. A substudy was run to evaluate the spontaneous speech data. In this study, a group of twelve college students were asked to evaluate the speech samples. A master tape of the spontaneous speech data was made by dubbing two IS-second samples of each patient and condition in random order onto a new tape. Samples were recorded at equal intensity levels and were played to the listeners at 75 dB SPL. Each listener was seated alone in a sound-treated room and heard the samples through the headphones. Listeners were asked to rate each 15second sample for “normalcy” using a l- 10 equal-appearing-interval scale where 1 indicated that the speech sounded completely normal and 10 indicated that the speech sounded very abnormal. Ratings of each patient and condition were averaged across listeners and across the two samples which had been selected for each condition. Measurement of oral sensory function. An oral form discrimination task was used to assessthe role of oral sensation in adaptation to surgery. Patients performed the oral form discrimination task immediately before surgery and 1 month, 3 months, 6 months, and 1 year after splint removal. The forms and procedures were the same as those reported by Ringel, Burk, and Scott. l1 Briefly, the patient was blindfolded and the experimenter presented the forms to the patient in pairs. The patient’s task was to explore two forms orally in succession and to determine whether the forms were the same or different. A total of ten practice trials and fifty-five test pairs were presented. The pairs were presented in a different random order during each testing period.
Volume 79 Number 1
Table
Effects
of speech
on surgical
premaxillary
osteotomy
57
I. Structural changes
Selected
hard-
and soft-tissue
measurements
Overjet Overbite ANB Upper central incisor: Sella-nasion Upper central incisor tip: Upper lip Nasolabial angle Inferior labial sulcus angle Superior labial sulcus: Subnasale-pogonion Inferior labial sulcus: Subnasale-pogonion Superior vermilion border: Subnasale-pogonion Inferior vermilion border: Subnasale-pogonion Lip opening
Mean
change
Range
of change
-6.0 mm. -1.0 mm. -4.1” +0.75” -2.33 mm. +8.9” +21.75” +1.9 mm. +o. 15 mm.
-7.0 to -5.0 mm. -2.0 to 0.0 mm. -5.5” to -2.0” -7” to +3” -5.5 to -1.5 mm. +3.5” to + 14.0” +10.5” to +52.0” f0.5 to +4.0 mm. -1.5 to +l.Omm.
+3.3
mm.
+ I .O to +5.0
mm.
+1.5 -4.16
mm. mm.
0.0 to +3.5 -7.5 to -2.0
mm. mm.
Results
Table I illustrates the means and ranges of selected hard- and soft-tissue measurements from dental casts and cephalometric x-ray films. Measurements of five dental casts were made twice to assessintraexaminer reliability. The average difference between the first and second measurements was 0.25 mm. with a range of 0.0 to 0.5 mm. On the dental casts, all patients exhibited a posterior repositioning of the upper teeth relative to the lower teeth as indicated by the mean decrease in overjet of 6.0 mm. with a range of 5.9 mm. to 7.0 mm. Vertical relationships of the upper and lower incisors were also changed. In five patients the overbite decreased, and in one it remained the same. The molar relationship remained the same in all patients, indicating very little change in the posterior dentition. The canine relationship, however, did change in all patients from Class II to Class I. Cephalometric data from one randomly selected patient were evaluated twice to assess intraexaminer reliability. The mean difference between the first and second angular measurements was 0.35 degrees, with a range of 0 to 2.0 degrees. The mean difference between the first and second linear measurements was 0.4 mm., with a range of 0 to 1.0 mm. On the x-rays, all patients exhibited a posterior repositioning of the premaxilla relative to the cranial base. The premaxilla was also posteriorly repositioned relative to the mandible. Very little change was observed in the mandible. Soft-tissue changes also were noted following surgery. The superior labial sulcus, superior vermilion border, inferior vermilion border, and inferior labial sulcus all were posteriorly repositioned. The nasolabial angle and inferior labial sulcus angle increased. Degree of lip opening decreased. Speech
measurements.
TASKS. Data for similar. Therefore, data will reliability of speech analyses data for eight conditions two READING
the word list, sentence list, and reading passage were quite be presented only for the reading passage. Intraexaminer was made by asking each speech pathologist to analyze the times. A Pearson Product Moment Correlation Coefficient
58
Garber,
Am. J. Orthod. Janua~ 1981
Speidel, and Marse 70 -
*Noise 60-
O-Quiet
250
-
0
k W40z z30E z20
-
IX 10 I
1
pre -
I
postSurgery
Fig. 1. The immediately
mean number after surgery,
I
1 mo.
Testing
i
3 mo.
1
6 mo.
I
1 yr.
Periods
of speech errors produced on the reading passage and 1 month, 3 months, 6 months, and 1 year after
task before splint removal.
surgery,
was computed for the number of errors counted by each observer during the first and second trials for each condition. The correlations for both Examiners 1 and 2 were 0.99. Fig. 1 displays the mean number of errors produced by patients before surgery, immediately after surgery, and 1 month, 3 months, 6 months, and 1 year after splint removal. The mean number of errors produced in quiet are represented by open circles, noise by closed circles. Immediately after surgery, the number of errors increased. By 1 month after splint removal, the number of errors was at presurgery levels. More errors were noted in noise than in quiet. However, there was no interaction between time periods and listening conditions. A two-factor repeated-measures analysis of variance was computed on the data. l2 The differences between times (presurgery, immediately postsurgery, etc.) were significant [F(2,10) = 10.67; p < .Ol] and the difference between listening conditions (noise versus quiet) was significant [F(1,5) = 32.72; p < .Ol]. The interaction between time periods and listening conditions was not significant (p > 0.05). Individual data revealed that five of six patients were at the presurgery level for number of errors by one month following splint removal. The one remaining patient reached the presurgery level within 3 months. At all time periods the majority of errors were distortions. Immediately after surgery, the increase in errors was accounted for by a disproportionate increase in distortions. The relative number of distortions returned to presurgery levels 1 month after splint removal. A chi-square test on distribution of errors at the different testing periods proved to be significant [X2(6) = 20.79; p < .Ol]. The distribution of phonemes most frequently in error was calculated. Immediately after surgery there was a disproportionate number of errors produced on Is/. Errors on Is/ returned to presurgery levels within 1 month after splint removal. Spontaneous speech task. The “normalcy” ratings for the spontaneous speech task are
Volume 79 Number
Effects
1
of speech
on surgical
premaxillay
59
osteotomy
O-Noise 6-
fGiuiet
5P ‘g 4 K
IX lY I
I
preSurgery Fig. 2. The mean speech evaluated the spontaneous
I
post-
rating assigned speech task.
I 3 mo.
1 mo. Testing
I 6 mo.
Periods
to patients
at different
testing
periods
by listeners
who
10r
g6
“1
c
2 w42-
Fig. 3. The mean
number
I
I
pre -
postSurgery
of errors
produced
I
1 mo. Testing
I 3 mo.
I 6 mo
I 1 yr.
Periods
on the oral form
discrimination
task in each
testing
period.
presented in Fig. 2. Ratings are on the ordinate, and time intervals are on the abscissa. Quiet conditions are represented by open circles, noise by closed circles. The average rating assigned to patients increased immediately after surgery but decreased to the presurgery level one month following splint removal. A slight drop in the ratings was noted at later testing periods. A higher rating was assigned in noise than in quiet but there was no interaction between the time intervals and listening conditions. A two-factor repeated-measures analysis of variance was computed on the data. The differences between times were significant [F(3,15) = 12.31; p < .OOl], and the differences between listening conditions were significant [F(1,5) = 6.61; p < .05]. The interaction between listening conditions and time was not significant. Individual data revealed that two patients returned to their presurgery ratings 1 month after splint removal. Three returned 3 months after splint removal, and one returned 6 months after splint removal. Oral form discrimination. The mean number of errors made by patients in the oral form discrimination test is illustrated in Fig. 3. Few errors were made during any of the
60
Gurber,
Speidel,
und Marse
Am. 1. Orthod. January 1981
test periods. The difference in errors across test periods was not significant (p > 0.05). No discernible pattern was seen in individual patients across testing periods. Discussion Structural changes. The structural changes measured following surgery consisted of a reduction in overjet due to the posterior repositioning of the premaxilla. In addition, posterior repositioning of corresponding soft tissues was noted. These changes are unremarkable and are similar to those reported by Kotteman.3 Only limited evaluations of lip competence can be made on the basis of these measurements. Yet, a common motivating factor for persons who seek orthognathic surgery is the complaint that they cannot close their lips comfortably at rest. On the basis of clinical judgments, no patient could achieve lip closure without some muscular strain prior to treatment. Clinical judgments made after surgery suggested a more relaxed facial countenance with increased ease of lip approximation at rest. These clinical judgments, as well as changes in lip posture revealed by evaluation of cephalometric x-rays, are consistent with the treatment objectives for the group. That is, it appears that patients can close their lips at rest more comfortably after surgery than before. However, it is important to note that there was a large individual variability among subjects. When asked to assume a resting posture for the presurgical cephalometric x-ray film, all six patients had their lips apart. Three of the six patients had their lips together in the posttreatment x-ray films, but three did not. Speech measurements. Speech deteriorated immediately following surgery. These effects may be due at least in part to the presence of the splint. Previous research indicates that orthodontic retainers which are similar to splints induce speech difficulties.‘3, I4 It is impossible to separate the effects of the splint from the effects of the surgery. However, it is interesting to note that Patient 3, who did not wear a splint, evidenced a speech disruption immediately after surgery. Orthodontic banding also may have influenced speech. l5 Because of time constraints, patients in the present study were not tested prior to banding. It would be useful in the future to test patients before and after banding as well as before and after surgery. Yet another variable which may be affecting speech is postsurgical swelling. Although most swelling had subsided by one week following surgery, some may have remained. It should be noted that a few speech errors were present during the reading task prior to surgery. Most likely this does not reflect a speech disorder on the part of the patients but, rather, reflects the fact that analyses were made from tape recordings instead of live and that raters were asked to make very fine discriminations. Thus, speech differences that were noted prior to surgery probably were not clinically significant. Recovery from surgery was a bit slower for spontaneous speech than for the reading tasks. Only two patients returned to their presurgery ratings 1 month after surgery. Three returned by 3 months and one by 6 months. Because one must formulate a message, spontaneous speech is a more stressful task than reading. Thus, it is not surprising that recovery was slower. The speech data indicate that premaxillary-setback patients are able to adapt quite well to surgery. Although the patients evidence speech disruptions immediately after surgery, there were no apparent long-term effects. In addition, the speech disruptions which did
Volume 79 Number 1
Effects of speech on surgical premaxillary
osteotomy
61
occur were not large. Immediately after surgery, naive listeners rated the patients’ speech as being moderately abnormal. Errors which occurred were mainly distortions. That is, patients generally were producing the appropriate phonemes but were producing them incorrectly. Hearing and oral sensory skills had little effect on adaptation to surgery. More speech errors were noted in noise than in quiet, but the relationship between noise and quiet was the same before and after surgery. There was no discernible change in oral sensory function following surgery. Relationship of structures and speech. Speech errors were noted immediately after surgery. What accounts for these errors ? By what process do patients adapt to the changes? An attempt was made to answer these questions by videotaping patients before and after surgery. It was hoped that assessment of lip and jaw movements during speech before and after surgery would help to delineate modes of adaptation. Unfortunately, it was very difficult to measure lip and jaw movements accurately from the videotapes. Thus, results were not reported. However, two very interesting patterns emerged. First, in function, the amount of visible incisor noted did not change following surgery. That is, the improvement in lip competence evident in cephalometric measurements at rest was not evident during function. Second, prior to surgery some patients displayed a pattern of forward mandibular movement during speech. This pattern sometimes continued following surgery. After surgery, the forward movement carried the lower incisors anterior to the upper incisors, which resulted in speech distortions. In order to document these intriguing observations, a videofluoroscopic examination of patients before and after surgery is planned. Tongue function also will be evaluated using the videofluoroscopic procedure. The tongue plays an active and important role in adaptation. Unfortunately, it is difficult to measure the tongue accurately with most procedures. It is hoped that measurements will be obtainable with the videofluoroscopic technique. REFERENCES 1. Lines, P. A., and Steinhauser, E. W.: Diagnosis and treatment planning in surgical orthodontic therapy, AM. J. ORTHOD. 66: 378-397, 1974. 2. Worms, F. W., Isaacson, R. J., and Speidel, T. M.: Surgical orthodontic treatment planning: Profile analysis and mandibular surgery, Angle Orthod. 46: l-25, 1976. 3. Kotteman, W. .I.: Mid-facial profile changes associated with maxillary subapical osteotomy, unpublished M.S.D. thesis, University of Minnesota, 1978. 4. Hershman, D. S., Tinsley, G. L., and Schow, C. E.: Apertognathia-An interdisciplinary approach: Report of case, J. Oral Surg. 30: 743-747, 1972. 5. Goodstein, B. A., Cooper, D., and Wallace, L.: The effect on speech of surgery for correction of mandibular prognathism, Oral Surg. 37: 846-849, 1974. 6. Wahoske, P.: The effects of surgically altering oral cavity relationships on speech production, Master’s thesis, University of Minnesota, 1975. 7. Turvey, T. A., Joumot, V., and Epker, B. N.: Correction of anterior open bite deformity: A study of tongue function, speech changes, and stability, J. Maxillofac. Surg. 4: 93-101, 1976. 8. Glass, L., Knapp, J., and Bloomer, H. H.: Speech and lingual behavior before and after mandibular osteotomy, J. Oral Surg. 35: 104-109, 1977. 9. Speidel, T. M., Marine, K., and Worms, F.: Soft tissue changes associated with mandibular subapical osteotomy, Angle Orthod. 49: 56-64, 1979. 10. Manning, W., Keappock, N., and Stick, S.: The use of auditory masking to estimate automatization of correct articulatory production, J. Speech Hear. Disord. 41: 143-149, 1976.
62
Garber,
Speidel, and Marse
Am. J. Orihod. January 1981
11. Ringel, R. L., Burk, K. W., and Scott, C. M.: Tactile perception: Form discrimination in the mouth, Br. J. Commun. Dis. 3: 150-15.5, 1968. 12. Winer, B.: Statistical principles in experimental design, New York, 1971, McGraw-Hill Book Company. 13. Erb, D. P.: Speech effects of the maxillary retainer, Angle Orthod. 37: 298-303, 1967. 14. Garber, S., Speidel, T. M., Siegel, G., Miller, E., and Glass, L.: The effects of presentation of noise and dental appliances on speech, J. Speech Hear. Res. (In press.) 15. Feldman, E. W.: Speech articulation problems associated with placement of orthodontic appliances, J. Speech Hear. Disord. 21: 34-38, 1956.