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Nasalance in patients with maxillary defects – Reconstruction versus obturation
ARTICLE IN PRESS Journal of Cranio-Maxillofacial Surgery (2007) 35, 241–245 r 2007 European Association for Cranio-Maxillofacial Surgery doi:10.1016/j.jcms.2007.07.001, available online at http://www.sciencedirect.com
Nasalance in patients with maxillary defects – Reconstruction versus obturation Andre´ ECKARDT1, Thomas TELTZROW2, Andrea SCHULZE3, Marijana HOPPE4, Christian KUETTNER5 1
Department of Oral and Maxillofacial Surgery (Chairman: Prof. Dr. Dr. N.C. Gellrich), Hannover Medical School, Hannover, Germany; 2Department of Oral and Maxillofacial Surgery (Chairman: PD Dr. Dr. V. Schwipper), Fachklinik Hornheide, Mu¨nster, Germany; 3Department of Orthodontics (Chairman: Prof. Dr. R.R. Miethke), Humboldt University Berlin, Charite´; 4Private Dental Office, Braunschweig, Germany; 5Private Maxillofacial Office, Wiesbaden, Germany
Background: An important question remains on how to obtain good quality of speech for patients needing maxillectomy. Oral and nasal spaces must be separated either by surgical means or by using an obturatorprosthesis. An objective measure of oronasal closure is nasalance. Different rehabilitative strategies should be compared. Methods: Between 1990 and 2000, 88 patients underwent maxillectomy of which 28 (32%) were available for examination. Ten patients had obturators (group l) and in 18 patients the maxilla was biologically reconstructed with different techniques (group 2). Sound pressure of nasal and oral airways were assessed seperately using a computerized sampling system (NasalViews) and standardized German texts. Nasalance was calculated and compared with an uncompromised sample of patients. Results: There were no significant differences between group 1 and group 2 concerning nasalance. Furthermore, the achieved values of nasalance were similar to healthy individuals. Conclusion: Nasalance after maxillectomy can be normal after sufficient rehabilitation. r 2007 European Association for Cranio-Maxillofacial Surgery
SUMMARY.
Keywords: nasalance, obturator, maxillectomy, maxillary reconstruction
been demonstrated that nasalance measurements with this instrument are closely related to perceptual judgements of oro-nasal sound balance (Hardin et al., 1992). Most of the available data was collected in English (Dalston et al., 1991; Hardin et al., 1992; Watterson et al., 1998) and used to assess altered speech due to anatomical change in the maxillary region, mainly associated with cleft lip palate. Normative values for the German language have been published (Stellzig and Komposch, 1994; Bressmann et al., 2000; Kuttner et al., 2003) but were collected with the Nasometer. Only a few publications deliver normative data to compare uncompromised German speakers with corresponding patients with altered speech (Kuttner et al., 2003). As is known from publications with the Nasometert, a high nasalance score is typically found in sounds with a high proportion of nasal soundpressure as in nasal consonants e.g. /m:/, /n:/ and /ng:/ (Mueller et al., 2000). Low nasalance in contrast was observed in sounds with a high yield of oral sound pressure as in vowels. Taking the work of Bressmann et al. (2000) into consideration, dealing with the clinical application of both instruments the results of the NasalView system can be compared with those of the Nasometer. In clinical routine the NasalView-System is easier to apply as it is mobile and compatible with a notebook. Furthermore the digital recording can be modified and a time-related
INTRODUCTION After maxillectomy, patients need complex rehabilitation by means of surgery and prosthodontics. Concerning speech the decision is often difficult, as to whether surgical reconstruction is better than obturation. Valid clinical data are scarce (Rieger et al., 2002) and long-term evaluation is compromised by a high mortality. Speech outcome measurements would be valuable in guiding treatment and the rehabilitation of patients needing maxillectomy. After tumour ablation or after midfacial trauma, closure of the communication between the oral cavity, maxillary sinus and nasal cavity is a surgical challenge. Insufficient oronasal closure can impair eating, drinking, swallowing and speech. Resonance behaviour and oronasal incompetence may change and lead to a more nasal sound to the voice and speech. In order to quantify the degree of alteration and to compare the results of different reconstructive strategies a standardized speech test in a consecutive group of patients was employed. By separating the sound pressure in the mouth and nose, a insufficient closure between both cavities can be registered. This method was first described by Shelton and Knox (1967) and with the Kay Nasometer 6200 (Kay Elemetrics, Lincoln Park NJ), a commercially available tool developed into a widely used instrument for the computerized measurement of nasalance. It has 241
ARTICLE IN PRESS 242 Journal of Cranio-Maxillofacial Surgery
selection is possible. The sound signal itself is not lost and can be reused.
MATERIAL AND METHODS All patients with maxillary defects and treatment for malignant tumours between 1990 and 2000 (n ¼ 88) were chosen for review of their clinical files and invited for clinical examination unless they had died or suffered from tumour recurrence. After receiving a written invitation, maxillectomy patients were examined clinically. An instrumental measure associated with the perception of nasal resonance is nasalance. The measure is derived by calculating the proportion of the nasal energy in speech from separate measurements of nasal and oral sound pressure levels (Fletcher and Bishop, 1970; Fletcher, 1976). Nasalance is defined as the ratio of nasal to nasal plus oral sound pressure as a percentage, with a nasalance score of 0–100. A new, PC-based instrument for the computerized measurement of nasalance is the NasalView (Awan, 1997 , Tiger Electronics, Seattle, WA, Fig. 1). The recordings are made with light weight headgear. A/D-signal conversion is achieved by a standard computer soundboard (Soundblaster Vibra 16, Creative Labs, Singapore). The sampling rate was 22.5 kHz stereo with 8-bit-signal conversion. The sampled sound signal or signal sections can be played back and edited with the NasalView programme oscillograms. Standardized German texts and sentences from the modified Heidelberg Rhinophonia assessment form were used containing different proportions of nasal sounds. The materials used were the vowels /a:/, /e:/, i:/, o:/, u:/, the sentences S1: ‘‘Die Schokolade ist sehr lecker’’ and S2: ‘‘Nenne meine Mamma Mimmi,’’ and the text passages of TP1: ‘‘Nordwind und Sonne’’,
Fig. 1 – Nasal view in clinical application: patient with headset of NasalViews-system [Tiger Electronics Inc., P.O. Box 75063, Seattle, WA 98125, USA]. The digital recording of oral and nasal sound pressure is registered with two seperate microphones. The acquired data can be directly transferred to a PC and evaluated with the software provided.
TP2: ‘‘Kindergeburtstag’’, and TP3: ‘‘Der grosse Gesang’’ (Table 1). The acquired and modified data from the NasalView software (Dr. Speech) was transferred to the SPSSt software, tested for normal distribution and the student’s t-test was applied with a null hypothesis po0.05). Patients were divided into two subgroups depending on the type of separation between oral and sinonasal cavities. Group 1 had undergone surgical reconstruction whereas in Group 2 an obturator was used.
RESULTS Patients Between 1990 and 2000, 88 patients underwent maxillectomy in the maxillofacial unit of Hannover Medical School. Histological diagnoses were as follows: squamous cell carcinoma n ¼ 53, adenoid-cystic carcinoma n ¼ 20, mucoepidermoid carcinoma n ¼ 6, other malignant tumours n ¼ 9. Patients with recurrence or tumour surgery less than one year before were excluded. From 68 surviving patients (77%) 28 patients (32%) attended for examination. The average time after tumour surgery was 5.4 years. The average age of the patients examined was 55.5 years (range 27–83 years). The ratio of male to female was 1:1.4. The maxillectomy defect in Group 1 (n ¼ 10) was classified as follows: Class 1 (n ¼ 3), Class 2a (n ¼ 6), Class 3a (n ¼ l); maxillectomy defects in Group 2 (n ¼ 18) were: Class 1 (n ¼ 4), Class 2a (n ¼ 6), Class 3a (n ¼ 6) and Class 4a (n ¼ 2). 10 patients had obturators, in 18 patients the defects were reconstructed with different techniques: 6 local flaps, e.g. palatal flaps or buccal fat pad flaps, and 12 microvascular flaps (radial forearm flap n ¼ 6, osteocutaneous fibula flap n ¼ 2, osteocutaneous scapula flap n ¼ l, latissimus dorsi myocutaneous flap n ¼ 3) were used. The results are shown in Table 2 comprising mean, maximum, minimum and standard deviations. Analysing the sequence of all vowels, a mean nasalance in the patients with obturators (group 1) of 39.7 (711.1) and of 40.2 (713) in the group of patients after reconstruction (group 2) was found. The highest nasalance was found for the vowel /i:/ with 44.8 (712.6) in group 1 and 45.5 (718.6) in group 2, the lowest in both groups for the vowels /a:/ and /o:/. In SI containing no nasal consonants, a nasalance of 29.1 (710.3) was found in group 1 and 31.6 (715.2) in group 2. S2 in contrast contained many nasal consonants leading to a nasalance of 70.3 (75.26) in group 1 and 68.3 (78.6) in group 2. The difference between nasalance of S1 and S2 was in both groups statistically significant (Pgroup1 ¼ 0.03 and pgroup2 ¼ 0.02). For the mixed texts there was no statistical difference within the groups and between the types of rehabilitation (Fig. 2). Nevertheless, the span of values was generally larger in the reconstructed group.
ARTICLE IN PRESS Nasalance in patients with maxillary defects 243 Table 1 – Text samples Vowels
Aaaaa eeeee iiiii ooooo uuuuu (sustained)
Sentences
SI S2
‘‘Die Schokolade ist sehr lecker’’ ‘‘Nenne meine Mama Mimi’’
Textpassages
TP1
‘‘Ein Kindergeburtstag’’ Ba¨rbel hat Geburtstag. Sie la¨dt ihre Freunde Annette, Susi, Britta und Bernd ein. Wie viele Kerzen brennen auf der Torte? Jeder schaut und za¨hlt: Ba¨rbel ist neun. Nun wollen sie gerne spielen. ‘‘Hast Du denn auch Gewinne fu¨r uns? Ich habe Goldtaler, Riesenlollies, Autos, Ketten, Murmeln und Springseile, alles in der Truhe. Wie der Blitz werfen die Kinder Steine weit und flach ins Wasser, dass es spritzt. ‘‘Tut das nicht, ruft die Mutter aus dem offenen Fenster die Stru¨mpfe werden nass!’’ Zum Schluss sitzen sie auf der Wiese, trinken heiXe Milch, essen Bro¨tchen mit Fleischwurst und Ka¨se und viel Schokoladenpudding.
TP2
‘‘Nordwind und Sonne’’ Einst stritten sich Nordwind und Sonne, wer von ihnen beiden wohl der Sta¨rkere wa¨re, als ein Wanderer des Weges kam. Der Wanderer war in einen warmen Mantel hu¨llt. Um zu erfahren, wer der Sta¨rkere war, wollten sie beide den Wanderer zwingen, seinen Mantel abzunehmen. Der Nordwind blies mit aller Macht, aber je mehr er blies, desto fester hu¨llte sich der Wanderer in seinen Mantel ein. Endlich gab der Nordwind den Kampf auf. Nun wa¨rmte die Sonne die Luft mit ihren freundlichen Strahlen, und schon nach wenigen Augenblicken zog der Wanderer seinen Mantel aus.
TP3
Auszug aus ‘‘Der Grosse Gesang’’ Blesshu¨hner fahren hupend umher und machen den See zum Rummel- und Tummelplatz. Das Ko¨ko¨ko¨k der Haubentaucher und das sa¨gende Ra¨b-ra¨b der Stockenten-Erpel fa¨hrt durch die du¨nnen Zweige der Faulba¨ume. Die Kraniche posaunen in den Seewiesen, und aus den Uferkiefern fa¨llt das sentimentale Liebesglucksen der Nebelkra¨hen.
Table 2 – Comparison of nasalance in group 1 versus group 2 Min.
Max.
Mean
SD
Nasalance patients with prosthodontic obturation (n ¼ 10) Vowels (total) 24.64 54.52 39.69 11.12 Vowel ‘‘a’’ 10.31 45.79 24.58 11.60 Vowel ‘‘e’’ 17.88 68.07 38.92 18.64 Vowel ‘‘i’’ 28.45 62.98 44.77 12.59 Vowel ‘‘o’’ 13.62 61.00 26.18 14.47 Vowel ‘‘u’’ 26.64 53.00 39.90 8.67 S1 15.09 46.50 29.05 10.33 S2 59.22 77.23 70.31 5.26 TP1 36.92 52.30 45.80 5.88 TP2 30.59 48.70 40.07 5.89 TP3 33.44 47.44 41.02 4.68 Nasalance patients with surgical reconstruction (n ¼ 18) Vowels (total) Vowel ‘‘a’’ Vowel ‘‘e’’ Vowel ‘‘i’’ Vowel ‘‘o’’ Vowel ‘‘u’’ S1 S2 TP1 TP2 TP3
22.96 13.10 16.03 20.95 10.17 14.82 14.25 48.23 34.33 25.73 27.48
68.73 51.01 76.01 86.34 67.33 74.41 72.89 80.99 71.65 71.45 70.57
40.24 30.82 35.19 45.53 29.58 41.69 31.64 68.34 46.79 42.19 42.07
12.97 10.20 17.45 18.55 16.34 17.35 15.24 8.61 10.61 12.32 12.24
Between the groups of reconstructed patients similar patterns of nasalance were found. There was no significant difference between both groups. In addition, comparison of nasalance of maxillectomy patients with healthy controls also revealed no statistically significant differences, although in all maxillectomy subgroups a trend towards higher mean nasalance values could be demonstrated (Fig. 3).
DISCUSSION With the current techniques available hypernasality after maxillectomy seems to be a minor problem for most patients. After sufficient rehabilitation, nasalance can be as low as in normal individuals. These results correspond with the findings of Rieger et al. (2002) who found no significant difference in patients with obturators compared to their pre-operative status, while speech without an obturator is significantly different from the pre-operative state. Rieger et al. did not include patients with surgical reconstruction in their study. Furthermore, a comparison of pre- and posttherapeutic results is of limited value due to the fact that the malignancy itself changes speech outcome. However, in some patients subjective and objective hypernasality is still present. Especially if the posterior edge of the soft palate is included in a maxillectomy defect, the functional consequences are more severe for the patient (Brown et al., 2000; Rieger et al., 2002). The number of patients assessed was too small for a systematic evaluation, but hypernasality was more often present in those patients with involvement of the soft palate. Several factors influenced the decision regarding what type of rehabilitation was employed. There was a predominance of local flaps for smaller defects; free flaps were preferred for larger defects. Obturators were mainly used when patients did not wish or could not tolerate extended operations. The size of the defect was a confounding variable as larger defects were more often reconstructed with microvascular flaps and smaller defects with local flaps. As is known from publications with the Nasometer, high nasalance values are found in speech
ARTICLE IN PRESS 244 Journal of Cranio-Maxillofacial Surgery
Patients after reconstruction vs. patients after prosthodontic obturation 80
reconstruction (n = 18) obturation (n = 10)
nasalance (mean)
60
40
20
0 vowels
S1
S2
TP1
TP2
TP3
test material Fig. 2 – Comparison of patients after reconstruction of maxillary defects with patients after prosthodontic obturation. Black columns: group 1 (n ¼ 18), white columns: group 2 (n ¼ 10).
Patients after maxillectomy vs. normal control 80 maxillary defect (n = 28) healthy control (n = 50)
nasalance (mean)
60
40
20
0 vowels
S1
S2 TP1 test material
TP2
TP3
Fig. 3 – Comparison of nasalance in patients after maxillectomy with normal control. Black columns: maxillary defect, white columns: healthy control group.
passages with a high proportion of nasal sound pressure as in the consonants /m:/, /n:/ and /ng:/ (Muller et al., 2000). Low nasalance values can be found in sounds with a high content of oral sound pressure like in most vowels. The nasalance values obtained from the maxillectomy patients were compared with the data from a test sample of 50 normal individuals collected by Kuttner et al. (2003). The results in patients after maxillectomy are consistent with these findings. Although no statistically significant difference between patients after maxillectomy and healthy patients could be demonstrated, there is a larger span of nasalance values in the maxillectomy group, indicating that there are individuals suffering from
altered speech due to anatomical change of the nasal airway. This corresponds with the subjective impression of nasal speech in some such patients. There might be a subgroup of patients where even a good reconstruction or a well fitting obturator is not capable of compensating for anatomical change. In those patients with nasal speech in spite of an obturator, a defect affecting the posterior border of the soft palate was often present. This is in accordance with Pauloski et al. (1998) describing the importance of this anatomical region for postoperative success in speech rehabilitation. Though not explicitly an aim of this study, it is important to define the cut-off score to differentiate between patients with and without hypernasality. Several authors (Dalston et al., 1991; Hardin et al., 1992) found that the nasometer differentiated between subjects with hypernasality and normal nasal resonance with a sensitivity and a specifity of around 80% when a cut-off of 30% nasalance was used. Watterson et al. (1998) reported a sensitivity of 84%. In the present group of patients no comparison of subjective and objective measurements was performed. Nevertheless, in patients with a nasalance of more than 30% in the text passages a hypernasality was noticed. CONCLUSION Maxillary defects are too scarce to obtain subgroups of sufficient size to exclude all confounding variables. However, there is a general tendency of good rehabilitative success in both groups: reconstruction and obturation. Comparing the sample of maxillectomy patients with a group of normal individuals, mean values are very similar but the span of values is larger in the reconstructed group indicating a possible
ARTICLE IN PRESS Nasalance in patients with maxillary defects 245
subgroup of patients suffering from either hyper- or hyponasality. Deviation from the mean was more often present in patients with involvement of the soft palate. Nevertheless, nasalance after maxillectomy after sufficient rehabilitation can be as low as in normal individuals. References Awan S: Analysis of nasalance: nasal view. In: Deger K (ed.), Clinical phonetics and linguistics. Whurr-Publishers: London, 427–518, 1997 Bressmann T, Sader R, et al.: Nasalance distance and ratio: two new measures. Cleft Palate Craniofac J 37: 248–256, 2000 Brown JS, Rogers SN, et al.: A modified classification for the maxillectomy defect. Head Neck 22: 17–26, 2000 Dalston RM, Warren DW, et al.: Use of nasometry as a diagnostic tool for identifying patients with velopharyngeal impairment. Cleft Palate Craniofac J 28: 184–188, 1991 discussion 188–189 Fletcher SG: Nasalance vs. listener judgements of nasality. Cleft Palate J 13: 31–44, 1976 Fletcher SG, Bishop ME: Measurement of nasality with tonar. Cleft Palate J 7: 610–621, 1970 Hardin MA, Van Demark DR, et al.: Correspondence between nasalance scores and listener judgments of hypernasality and hyponasality. Cleft Palate Craniofac J 29: 346–351, 1992 Kuttner C, Brucher JJ, et al.: Langzeitergebnisse nach Velopharyngoplastik bei Patienten mit Spaltbildungen des Gaumens. Mund Kiefer Gesichtschir 7: 76–82, 2003 Muller R, Beleites T, et al.: Objective measurement of normal nasality in the Saxony dialect. HNO 48: 937–942, 2000
Pauloski BR, Logemann JA, et al.: Surgical variables affecting speech in treated patients with oral and oropharyngeal cancer. Laryngoscope 108 (6): 908–916, 1998 Rieger J, Wolfaardt J, et al.: Speech outcomes in patients rehabilitated with maxillary obturator prostheses after maxillectomy: a prospective study. Int J Prosthodont 15: 139–144, 2002 Shelton Jr. RL, Knox AW, et al.: The relationship between nasality score values and oral and nasal sound pressure level. J Speech Hear Res 10: 549–557, 1967 Stellzig A, Komposch G: Hyperrhinophonia and craniofacial structure. A cephalometric analysis. Fortschr Kieferorthop 55: 181–185, 1994 Watterson T, Lewis KE, et al.: Nasalance and nasality in low pressure and high pressure speech. Cleft Palate Craniofac J 35: 293–298, 1998
Andre´ Eckardt, MD, DDS, PhD Department of Oral and Maxillofacial Surgery Hannover Medical School Carl-Neuberg-Strasse 1 Hannover 30625 Germany Tel.: +49 511 532 4879 Fax: +49 511 532 8879 E-mail: [email protected] Paper received 14 March 2006 Accepted 9 July 2007
Nasalance in patients with maxillary defects – Reconstruction versus obturation Andre´ ECKARDT1, Thomas TELTZROW2, Andrea SCHULZE3, Marijana HOPPE4, Christian KUETTNER5 1
Department of Oral and Maxillofacial Surgery (Chairman: Prof. Dr. Dr. N.C. Gellrich), Hannover Medical School, Hannover, Germany; 2Department of Oral and Maxillofacial Surgery (Chairman: PD Dr. Dr. V. Schwipper), Fachklinik Hornheide, Mu¨nster, Germany; 3Department of Orthodontics (Chairman: Prof. Dr. R.R. Miethke), Humboldt University Berlin, Charite´; 4Private Dental Office, Braunschweig, Germany; 5Private Maxillofacial Office, Wiesbaden, Germany
Background: An important question remains on how to obtain good quality of speech for patients needing maxillectomy. Oral and nasal spaces must be separated either by surgical means or by using an obturatorprosthesis. An objective measure of oronasal closure is nasalance. Different rehabilitative strategies should be compared. Methods: Between 1990 and 2000, 88 patients underwent maxillectomy of which 28 (32%) were available for examination. Ten patients had obturators (group l) and in 18 patients the maxilla was biologically reconstructed with different techniques (group 2). Sound pressure of nasal and oral airways were assessed seperately using a computerized sampling system (NasalViews) and standardized German texts. Nasalance was calculated and compared with an uncompromised sample of patients. Results: There were no significant differences between group 1 and group 2 concerning nasalance. Furthermore, the achieved values of nasalance were similar to healthy individuals. Conclusion: Nasalance after maxillectomy can be normal after sufficient rehabilitation. r 2007 European Association for Cranio-Maxillofacial Surgery
SUMMARY.
Keywords: nasalance, obturator, maxillectomy, maxillary reconstruction
been demonstrated that nasalance measurements with this instrument are closely related to perceptual judgements of oro-nasal sound balance (Hardin et al., 1992). Most of the available data was collected in English (Dalston et al., 1991; Hardin et al., 1992; Watterson et al., 1998) and used to assess altered speech due to anatomical change in the maxillary region, mainly associated with cleft lip palate. Normative values for the German language have been published (Stellzig and Komposch, 1994; Bressmann et al., 2000; Kuttner et al., 2003) but were collected with the Nasometer. Only a few publications deliver normative data to compare uncompromised German speakers with corresponding patients with altered speech (Kuttner et al., 2003). As is known from publications with the Nasometert, a high nasalance score is typically found in sounds with a high proportion of nasal soundpressure as in nasal consonants e.g. /m:/, /n:/ and /ng:/ (Mueller et al., 2000). Low nasalance in contrast was observed in sounds with a high yield of oral sound pressure as in vowels. Taking the work of Bressmann et al. (2000) into consideration, dealing with the clinical application of both instruments the results of the NasalView system can be compared with those of the Nasometer. In clinical routine the NasalView-System is easier to apply as it is mobile and compatible with a notebook. Furthermore the digital recording can be modified and a time-related
INTRODUCTION After maxillectomy, patients need complex rehabilitation by means of surgery and prosthodontics. Concerning speech the decision is often difficult, as to whether surgical reconstruction is better than obturation. Valid clinical data are scarce (Rieger et al., 2002) and long-term evaluation is compromised by a high mortality. Speech outcome measurements would be valuable in guiding treatment and the rehabilitation of patients needing maxillectomy. After tumour ablation or after midfacial trauma, closure of the communication between the oral cavity, maxillary sinus and nasal cavity is a surgical challenge. Insufficient oronasal closure can impair eating, drinking, swallowing and speech. Resonance behaviour and oronasal incompetence may change and lead to a more nasal sound to the voice and speech. In order to quantify the degree of alteration and to compare the results of different reconstructive strategies a standardized speech test in a consecutive group of patients was employed. By separating the sound pressure in the mouth and nose, a insufficient closure between both cavities can be registered. This method was first described by Shelton and Knox (1967) and with the Kay Nasometer 6200 (Kay Elemetrics, Lincoln Park NJ), a commercially available tool developed into a widely used instrument for the computerized measurement of nasalance. It has 241
ARTICLE IN PRESS 242 Journal of Cranio-Maxillofacial Surgery
selection is possible. The sound signal itself is not lost and can be reused.
MATERIAL AND METHODS All patients with maxillary defects and treatment for malignant tumours between 1990 and 2000 (n ¼ 88) were chosen for review of their clinical files and invited for clinical examination unless they had died or suffered from tumour recurrence. After receiving a written invitation, maxillectomy patients were examined clinically. An instrumental measure associated with the perception of nasal resonance is nasalance. The measure is derived by calculating the proportion of the nasal energy in speech from separate measurements of nasal and oral sound pressure levels (Fletcher and Bishop, 1970; Fletcher, 1976). Nasalance is defined as the ratio of nasal to nasal plus oral sound pressure as a percentage, with a nasalance score of 0–100. A new, PC-based instrument for the computerized measurement of nasalance is the NasalView (Awan, 1997 , Tiger Electronics, Seattle, WA, Fig. 1). The recordings are made with light weight headgear. A/D-signal conversion is achieved by a standard computer soundboard (Soundblaster Vibra 16, Creative Labs, Singapore). The sampling rate was 22.5 kHz stereo with 8-bit-signal conversion. The sampled sound signal or signal sections can be played back and edited with the NasalView programme oscillograms. Standardized German texts and sentences from the modified Heidelberg Rhinophonia assessment form were used containing different proportions of nasal sounds. The materials used were the vowels /a:/, /e:/, i:/, o:/, u:/, the sentences S1: ‘‘Die Schokolade ist sehr lecker’’ and S2: ‘‘Nenne meine Mamma Mimmi,’’ and the text passages of TP1: ‘‘Nordwind und Sonne’’,
Fig. 1 – Nasal view in clinical application: patient with headset of NasalViews-system [Tiger Electronics Inc., P.O. Box 75063, Seattle, WA 98125, USA]. The digital recording of oral and nasal sound pressure is registered with two seperate microphones. The acquired data can be directly transferred to a PC and evaluated with the software provided.
TP2: ‘‘Kindergeburtstag’’, and TP3: ‘‘Der grosse Gesang’’ (Table 1). The acquired and modified data from the NasalView software (Dr. Speech) was transferred to the SPSSt software, tested for normal distribution and the student’s t-test was applied with a null hypothesis po0.05). Patients were divided into two subgroups depending on the type of separation between oral and sinonasal cavities. Group 1 had undergone surgical reconstruction whereas in Group 2 an obturator was used.
RESULTS Patients Between 1990 and 2000, 88 patients underwent maxillectomy in the maxillofacial unit of Hannover Medical School. Histological diagnoses were as follows: squamous cell carcinoma n ¼ 53, adenoid-cystic carcinoma n ¼ 20, mucoepidermoid carcinoma n ¼ 6, other malignant tumours n ¼ 9. Patients with recurrence or tumour surgery less than one year before were excluded. From 68 surviving patients (77%) 28 patients (32%) attended for examination. The average time after tumour surgery was 5.4 years. The average age of the patients examined was 55.5 years (range 27–83 years). The ratio of male to female was 1:1.4. The maxillectomy defect in Group 1 (n ¼ 10) was classified as follows: Class 1 (n ¼ 3), Class 2a (n ¼ 6), Class 3a (n ¼ l); maxillectomy defects in Group 2 (n ¼ 18) were: Class 1 (n ¼ 4), Class 2a (n ¼ 6), Class 3a (n ¼ 6) and Class 4a (n ¼ 2). 10 patients had obturators, in 18 patients the defects were reconstructed with different techniques: 6 local flaps, e.g. palatal flaps or buccal fat pad flaps, and 12 microvascular flaps (radial forearm flap n ¼ 6, osteocutaneous fibula flap n ¼ 2, osteocutaneous scapula flap n ¼ l, latissimus dorsi myocutaneous flap n ¼ 3) were used. The results are shown in Table 2 comprising mean, maximum, minimum and standard deviations. Analysing the sequence of all vowels, a mean nasalance in the patients with obturators (group 1) of 39.7 (711.1) and of 40.2 (713) in the group of patients after reconstruction (group 2) was found. The highest nasalance was found for the vowel /i:/ with 44.8 (712.6) in group 1 and 45.5 (718.6) in group 2, the lowest in both groups for the vowels /a:/ and /o:/. In SI containing no nasal consonants, a nasalance of 29.1 (710.3) was found in group 1 and 31.6 (715.2) in group 2. S2 in contrast contained many nasal consonants leading to a nasalance of 70.3 (75.26) in group 1 and 68.3 (78.6) in group 2. The difference between nasalance of S1 and S2 was in both groups statistically significant (Pgroup1 ¼ 0.03 and pgroup2 ¼ 0.02). For the mixed texts there was no statistical difference within the groups and between the types of rehabilitation (Fig. 2). Nevertheless, the span of values was generally larger in the reconstructed group.
ARTICLE IN PRESS Nasalance in patients with maxillary defects 243 Table 1 – Text samples Vowels
Aaaaa eeeee iiiii ooooo uuuuu (sustained)
Sentences
SI S2
‘‘Die Schokolade ist sehr lecker’’ ‘‘Nenne meine Mama Mimi’’
Textpassages
TP1
‘‘Ein Kindergeburtstag’’ Ba¨rbel hat Geburtstag. Sie la¨dt ihre Freunde Annette, Susi, Britta und Bernd ein. Wie viele Kerzen brennen auf der Torte? Jeder schaut und za¨hlt: Ba¨rbel ist neun. Nun wollen sie gerne spielen. ‘‘Hast Du denn auch Gewinne fu¨r uns? Ich habe Goldtaler, Riesenlollies, Autos, Ketten, Murmeln und Springseile, alles in der Truhe. Wie der Blitz werfen die Kinder Steine weit und flach ins Wasser, dass es spritzt. ‘‘Tut das nicht, ruft die Mutter aus dem offenen Fenster die Stru¨mpfe werden nass!’’ Zum Schluss sitzen sie auf der Wiese, trinken heiXe Milch, essen Bro¨tchen mit Fleischwurst und Ka¨se und viel Schokoladenpudding.
TP2
‘‘Nordwind und Sonne’’ Einst stritten sich Nordwind und Sonne, wer von ihnen beiden wohl der Sta¨rkere wa¨re, als ein Wanderer des Weges kam. Der Wanderer war in einen warmen Mantel hu¨llt. Um zu erfahren, wer der Sta¨rkere war, wollten sie beide den Wanderer zwingen, seinen Mantel abzunehmen. Der Nordwind blies mit aller Macht, aber je mehr er blies, desto fester hu¨llte sich der Wanderer in seinen Mantel ein. Endlich gab der Nordwind den Kampf auf. Nun wa¨rmte die Sonne die Luft mit ihren freundlichen Strahlen, und schon nach wenigen Augenblicken zog der Wanderer seinen Mantel aus.
TP3
Auszug aus ‘‘Der Grosse Gesang’’ Blesshu¨hner fahren hupend umher und machen den See zum Rummel- und Tummelplatz. Das Ko¨ko¨ko¨k der Haubentaucher und das sa¨gende Ra¨b-ra¨b der Stockenten-Erpel fa¨hrt durch die du¨nnen Zweige der Faulba¨ume. Die Kraniche posaunen in den Seewiesen, und aus den Uferkiefern fa¨llt das sentimentale Liebesglucksen der Nebelkra¨hen.
Table 2 – Comparison of nasalance in group 1 versus group 2 Min.
Max.
Mean
SD
Nasalance patients with prosthodontic obturation (n ¼ 10) Vowels (total) 24.64 54.52 39.69 11.12 Vowel ‘‘a’’ 10.31 45.79 24.58 11.60 Vowel ‘‘e’’ 17.88 68.07 38.92 18.64 Vowel ‘‘i’’ 28.45 62.98 44.77 12.59 Vowel ‘‘o’’ 13.62 61.00 26.18 14.47 Vowel ‘‘u’’ 26.64 53.00 39.90 8.67 S1 15.09 46.50 29.05 10.33 S2 59.22 77.23 70.31 5.26 TP1 36.92 52.30 45.80 5.88 TP2 30.59 48.70 40.07 5.89 TP3 33.44 47.44 41.02 4.68 Nasalance patients with surgical reconstruction (n ¼ 18) Vowels (total) Vowel ‘‘a’’ Vowel ‘‘e’’ Vowel ‘‘i’’ Vowel ‘‘o’’ Vowel ‘‘u’’ S1 S2 TP1 TP2 TP3
22.96 13.10 16.03 20.95 10.17 14.82 14.25 48.23 34.33 25.73 27.48
68.73 51.01 76.01 86.34 67.33 74.41 72.89 80.99 71.65 71.45 70.57
40.24 30.82 35.19 45.53 29.58 41.69 31.64 68.34 46.79 42.19 42.07
12.97 10.20 17.45 18.55 16.34 17.35 15.24 8.61 10.61 12.32 12.24
Between the groups of reconstructed patients similar patterns of nasalance were found. There was no significant difference between both groups. In addition, comparison of nasalance of maxillectomy patients with healthy controls also revealed no statistically significant differences, although in all maxillectomy subgroups a trend towards higher mean nasalance values could be demonstrated (Fig. 3).
DISCUSSION With the current techniques available hypernasality after maxillectomy seems to be a minor problem for most patients. After sufficient rehabilitation, nasalance can be as low as in normal individuals. These results correspond with the findings of Rieger et al. (2002) who found no significant difference in patients with obturators compared to their pre-operative status, while speech without an obturator is significantly different from the pre-operative state. Rieger et al. did not include patients with surgical reconstruction in their study. Furthermore, a comparison of pre- and posttherapeutic results is of limited value due to the fact that the malignancy itself changes speech outcome. However, in some patients subjective and objective hypernasality is still present. Especially if the posterior edge of the soft palate is included in a maxillectomy defect, the functional consequences are more severe for the patient (Brown et al., 2000; Rieger et al., 2002). The number of patients assessed was too small for a systematic evaluation, but hypernasality was more often present in those patients with involvement of the soft palate. Several factors influenced the decision regarding what type of rehabilitation was employed. There was a predominance of local flaps for smaller defects; free flaps were preferred for larger defects. Obturators were mainly used when patients did not wish or could not tolerate extended operations. The size of the defect was a confounding variable as larger defects were more often reconstructed with microvascular flaps and smaller defects with local flaps. As is known from publications with the Nasometer, high nasalance values are found in speech
ARTICLE IN PRESS 244 Journal of Cranio-Maxillofacial Surgery
Patients after reconstruction vs. patients after prosthodontic obturation 80
reconstruction (n = 18) obturation (n = 10)
nasalance (mean)
60
40
20
0 vowels
S1
S2
TP1
TP2
TP3
test material Fig. 2 – Comparison of patients after reconstruction of maxillary defects with patients after prosthodontic obturation. Black columns: group 1 (n ¼ 18), white columns: group 2 (n ¼ 10).
Patients after maxillectomy vs. normal control 80 maxillary defect (n = 28) healthy control (n = 50)
nasalance (mean)
60
40
20
0 vowels
S1
S2 TP1 test material
TP2
TP3
Fig. 3 – Comparison of nasalance in patients after maxillectomy with normal control. Black columns: maxillary defect, white columns: healthy control group.
passages with a high proportion of nasal sound pressure as in the consonants /m:/, /n:/ and /ng:/ (Muller et al., 2000). Low nasalance values can be found in sounds with a high content of oral sound pressure like in most vowels. The nasalance values obtained from the maxillectomy patients were compared with the data from a test sample of 50 normal individuals collected by Kuttner et al. (2003). The results in patients after maxillectomy are consistent with these findings. Although no statistically significant difference between patients after maxillectomy and healthy patients could be demonstrated, there is a larger span of nasalance values in the maxillectomy group, indicating that there are individuals suffering from
altered speech due to anatomical change of the nasal airway. This corresponds with the subjective impression of nasal speech in some such patients. There might be a subgroup of patients where even a good reconstruction or a well fitting obturator is not capable of compensating for anatomical change. In those patients with nasal speech in spite of an obturator, a defect affecting the posterior border of the soft palate was often present. This is in accordance with Pauloski et al. (1998) describing the importance of this anatomical region for postoperative success in speech rehabilitation. Though not explicitly an aim of this study, it is important to define the cut-off score to differentiate between patients with and without hypernasality. Several authors (Dalston et al., 1991; Hardin et al., 1992) found that the nasometer differentiated between subjects with hypernasality and normal nasal resonance with a sensitivity and a specifity of around 80% when a cut-off of 30% nasalance was used. Watterson et al. (1998) reported a sensitivity of 84%. In the present group of patients no comparison of subjective and objective measurements was performed. Nevertheless, in patients with a nasalance of more than 30% in the text passages a hypernasality was noticed. CONCLUSION Maxillary defects are too scarce to obtain subgroups of sufficient size to exclude all confounding variables. However, there is a general tendency of good rehabilitative success in both groups: reconstruction and obturation. Comparing the sample of maxillectomy patients with a group of normal individuals, mean values are very similar but the span of values is larger in the reconstructed group indicating a possible
ARTICLE IN PRESS Nasalance in patients with maxillary defects 245
subgroup of patients suffering from either hyper- or hyponasality. Deviation from the mean was more often present in patients with involvement of the soft palate. Nevertheless, nasalance after maxillectomy after sufficient rehabilitation can be as low as in normal individuals. References Awan S: Analysis of nasalance: nasal view. In: Deger K (ed.), Clinical phonetics and linguistics. Whurr-Publishers: London, 427–518, 1997 Bressmann T, Sader R, et al.: Nasalance distance and ratio: two new measures. Cleft Palate Craniofac J 37: 248–256, 2000 Brown JS, Rogers SN, et al.: A modified classification for the maxillectomy defect. Head Neck 22: 17–26, 2000 Dalston RM, Warren DW, et al.: Use of nasometry as a diagnostic tool for identifying patients with velopharyngeal impairment. Cleft Palate Craniofac J 28: 184–188, 1991 discussion 188–189 Fletcher SG: Nasalance vs. listener judgements of nasality. Cleft Palate J 13: 31–44, 1976 Fletcher SG, Bishop ME: Measurement of nasality with tonar. Cleft Palate J 7: 610–621, 1970 Hardin MA, Van Demark DR, et al.: Correspondence between nasalance scores and listener judgments of hypernasality and hyponasality. Cleft Palate Craniofac J 29: 346–351, 1992 Kuttner C, Brucher JJ, et al.: Langzeitergebnisse nach Velopharyngoplastik bei Patienten mit Spaltbildungen des Gaumens. Mund Kiefer Gesichtschir 7: 76–82, 2003 Muller R, Beleites T, et al.: Objective measurement of normal nasality in the Saxony dialect. HNO 48: 937–942, 2000
Pauloski BR, Logemann JA, et al.: Surgical variables affecting speech in treated patients with oral and oropharyngeal cancer. Laryngoscope 108 (6): 908–916, 1998 Rieger J, Wolfaardt J, et al.: Speech outcomes in patients rehabilitated with maxillary obturator prostheses after maxillectomy: a prospective study. Int J Prosthodont 15: 139–144, 2002 Shelton Jr. RL, Knox AW, et al.: The relationship between nasality score values and oral and nasal sound pressure level. J Speech Hear Res 10: 549–557, 1967 Stellzig A, Komposch G: Hyperrhinophonia and craniofacial structure. A cephalometric analysis. Fortschr Kieferorthop 55: 181–185, 1994 Watterson T, Lewis KE, et al.: Nasalance and nasality in low pressure and high pressure speech. Cleft Palate Craniofac J 35: 293–298, 1998
Andre´ Eckardt, MD, DDS, PhD Department of Oral and Maxillofacial Surgery Hannover Medical School Carl-Neuberg-Strasse 1 Hannover 30625 Germany Tel.: +49 511 532 4879 Fax: +49 511 532 8879 E-mail: [email protected] Paper received 14 March 2006 Accepted 9 July 2007