Anthony T. Macari

New insights on age-related association between nasopharyngeal airway clearance and facial morphology

OBJECTIVES To evaluate the relation between adenoid hypertrophy and facial morphology across age in a pediatric population. SETTING AND SAMPLE POPULATION The American University of Beirut Department of Otolaryngology. Two-hundred consecutive children (age 6.00 ± 2.62 years) referred from the Pediatric Otolaryngology unit to the Orthodontic division and requiring a lateral cephalogram for adenoid hypertrophy assessment. METHODS Cephalometric measurements included relations among cranial base, maxilla and mandible, and airway clearance measured from adenoid to soft palate (AD). The children were classified into two age groups, Group 1: ≤ 6 years (n = 124) and Group 2: ≥ 6.01 years (n = 76), and also stratified in four subgroups (A, B, C, D) based on maxillo-mandibular divergence (palatal to mandibular plane angle, PP-MP): A- PP-MP ≤ 27.5°, n = 34; B- 27.5° < PP-MP ≤ 32°, n = 68; C- 32°<PP/MP<36.5°, n = 67; D- PP-MP ≥ 36.5°, n = 31. Statistics included t-tests and anova for group differences. RESULTS   Differences between groups 1 and 2 were statistically significant (p < 0.05) for AD (Group 1: 3.19 ± 2.32 mm, Group 2: 4.78 ± 2.80 mm), ANB (5.38 ± 2.24°, 4.38 ± 2.54°), LFH (56.61 ± 1.95%, 55.38 ± 1.84%), PP-H (-8.41 ± 3.28°, -6.49 ± 3.46°), and overbite (0.55 ± 2.00 mm, 1.16 ± 2.36 mm). Among subgroups, statistically significant differences (p < 0.05) occurred mainly between the most hyperdivergent group (D) and the hypodivergent (A) and normodivergent (B) groups. CONCLUSIONS Airway measurements were smallest in children ≤ 6 years and those presenting severe hyperdivergent pattern, which denoted the most severe airway obstruction. The findings suggest airway clearance before age 6 in the most severely affected children, but follow-up research on actual adenoidectomies in younger children is needed to determine guidelines.

Correspondence Between Subjective and Linear Measurements of the Palatal Airway on Lateral Cephalometric Radiographs

OBJECTIVE To evaluate the correlation between and significance of 2 methods of palatal airway assessment on lateral cephalographs. DESIGN Diagnostic lateral cephalometric imaging study that took place from January 1, 2006, to December 31, 2007. SETTING American University of Beirut Medical Center. PATIENTS Children with chronic mouth breathing referred by a pediatric otolaryngologist for cephalometric evaluation by participating orthodontists. MAIN OUTCOME MEASURES Two distances were measured on the digitized lateral cephalographs between the adenoid and soft palate: the shortest adenoid distance (SAD) and the most convex adenoid distance (CAD). The palatal airway was assessed on a grade-1 to grade-3 scale independently by the referring otolaryngologist and an orthodontist. RESULTS A total of 200 children were included in the study (127 boys and 73 girls; mean age, 6 years; age range, 1.71-12.62 years). High correlations were observed between the airway ratings gathered by both examiners (r = 0.96) and between SAD and CAD (r = 0.92). Significant correlations were noted between the palatal airway grade and the SAD and CAD measurements (r = -0.73 and r = -0.79, respectively). Shortest adenoid distance measures of 2 mm or less corresponded mostly to grade 3 obstruction and were more prevalent in patients younger than 6 years. Age was inversely proportional to both the grade and SAD (P < .001). CONCLUSIONS Both methods are reliable for assessment of airway obstruction by the adenoid. Because SAD and CAD are highly correlated, we recommend the use of SAD as a more readily identifiable distance on cephalometric radiographs. Removal of adenoids when SAD is less than 2 mm may be indicated because this condition reflects a severe airway obstruction associated with potential changes in dentofacial structure.

Correlation Between the Position of the Hyoid Bone on Lateral Cephalographs and Formant Frequencies

OBJECTIVES The objective of this study is to examine the F1, F2, F3, and F4 during sustained vowels /ɑ/, /i/, /o/, /u/. STUDY DESIGN Prospective cross-sectional study. METHODS Fifty-two consecutive patients aged between 9 years and 38 years were invited to participate in this study. Linear measurements included linear vertical distance from the hyoid bone to the sella turcica (H-S); linear vertical distance from the hyoid bone to the posterior nasal spine (H-PNS); linear measure from the hyoid bone to the most anterior point of the cervical vertebra C3 (H-C3); and linear vertical distance from the hyoid bone to the mandibular plane (H-MP). RESULTS The results showed a moderate and statistically significant correlation between the average fundamental frequency for the vowel /ɑ/ and H-C3, H-S, and H-PNS and another moderate negative correlation between F3 and F4, and the vertical position of the hyoid bone H-C3 and H-S. For the vowel /i/, there was a moderate negative correlation between F1, F3, and F4 and H-S and also a moderate negative correlation between F3 and F4 and H-C3. For the vowel /o/, there was a moderate negative correlation between F4 and H-S and H-PNS. For the vowel /u/, only F4 correlated significantly with H-S. CONCLUSION There is a moderate correlation between the high formants, mostly F4, and the cephalo-caudal position of the hyoid bone.

Formants Frequency and Dispersion in Relation to the Length and Projection of the Upper and Lower Jaws

OBJECTIVE Investigate the association between formants frequencies and length and sagittal projection of the maxilla and mandible. STUDY DESIGN Cross-sectional study. METHOD A total of 47 consecutive patients were recruited. Craniofacial measures included; maxillary length (ANS-PNS), mandibular length (Co-Gn), relationship between maxilla and mandible in the sagittal plane (ANB), the sagittal projection of the maxilla (SNA), and mandible (SNB). Subjects were asked to phonate vowels /a/, /i/, /o/, and /u/. Measurements were made in real-time and formant frequencies across F1, F2, F3, and F4 were determined. RESULTS There was a significant negative association between the length of the maxilla and F4 for all the vowels, and a significant negative association between the length of the mandible and F4 for vowels /o/ and /u/. The length of maxilla and mandible also negatively associated with F3 for vowels /a/, /i/, /o/, and vowels /i/, /o/, and /u/ respectively. For the first two formants, the negative association was less pronounced. CONCLUSION There was a significant negative association between the formant frequencies F3, F4, and the length of the mandible and maxilla for vowels /a/, /i/, /o/, and /u/.

Correlation between the length and sagittal projection of the upper and lower jaw and the fundamental frequency

OBJECTIVE To report on the correlation between the length and projection of the upper and lower jaw and the fundamental frequency (F0). STUDY DESIGN Prospective study. MATERIALS AND METHODS A total of 45 healthy subjects were included in this study. The facial skeletal measurements included: SNA, SNB, ANB, angles that reflect the position of the maxilla and mandible in relation to the base of skull and to each others, length of mandible Co-Gn, and length of maxilla PNS-ANS. All subjects underwent acoustic analysis using VISI-PITCH IV. RESULTS The means for F0 and habitual frequency were 220.75 + 40.01 Hz and 216.99 + 43.9 Hz, respectively. The means for SNA, SNB, and ANB were 80.753 ± 3.20, 77.409 ± 3.64, and 3.336 ± 2.57, respectively. The mean length of the mandible and maxilla were 104.28 + 7.94 and 50.29 + 3.94, respectively. In the total group, there was a moderate negative correlation between F0 and habitual frequency and the length of the mandible (r = -0.528 and -0.577, respectively). There was also a moderate negative correlation between F0 and habitual frequency and the length of the maxilla (r = -0.473 and -0.519, respectively). Similar findings were present after excluding the pubertal subjects. With respect to the other cephalometric measurements, the correlation was poor (r value < 0.3). CONCLUSIONS There is a moderate negative correlation between the length of the upper and lower jaw and the average F0 and habitual frequency. The remaining facial sagittal projection parameters do not correlate with the average F0 and habitual frequency.

Instability of palatal rugae following rapid maxillary expansion

Background Existing evidence on changes of the palatal rugae following rapid maxillary expansion (RME) is scarce and inconclusive, particularly immediate post-expansion changes in three-dimensional assessments. Objectives Our aims were to assess the dimensional stability of the palatal rugae in the antero-posterior and transverse dimensions following RME treatment, as well as the three-dimensional changes in palatal volume and area. Material and methods The sample consisted of the dental casts of 30 adolescents (16 males; 14 females, age 11.46 ± 1.42 years) who underwent RME. The models, available at T1 (pretreatment) and T2 (immediately after expansion) were scanned using a laser scanning system. Various parameters were recorded including individual ruga transverse and antero-posterior linear and angular measurements; palatal dimensions (width, length, volume, surface area, vault depth/height); and dental characteristics (interincisor, intercanine, interpremolar, and intermolar distances). Statistical analyses included paired t-tests for group comparisons, and Pearson moment product for associations among variables. Results Palatal rugae were altered by RME in all dimensions in both linear and angular measurements, almost equally on right and left sides, albeit the average linear changes were about 1 mm. Correlation coefficients among rugal and dental measures suggested an association between rugae changes and the underlying bony movements. Except for the first rugae that had higher correlations to the intercanine width, the correspondence of changes seems to be asymmetric, thus not precisely predictable. Conclusions The results suggest a variable trend in the rugae response to expansion, likely reflecting the constitutional asymmetric pattern or nature of pairs of rugae.

Effect of Rapid Maxillary Expansion on Voice.

OBJECTIVE The purpose of this investigation is to evaluate the effect of rapid maxillary expansion (RME) on the fundamental frequency (F0) and formant frequencies F1-F4. STUDY DESIGN Cross-sectional study. MATERIALS AND METHODS A total of 14 consecutive patients between the ages of 9.6 years and 15 years with a constricted maxilla undergoing RME were included in this study. Measurements were made before (T1) and after treatment (T2). These included maxillary arch length, depth, width, and perimeter in addition to F0, habitual pitch, and formants F1, F2, F3, and F4 for the vowels /ɑ/, /i/, /o/, and /u/. RESULTS There was a significant difference in the mean of F1/ɑ/ and F2/ɑ/ before and after treatment (P value of 0.04 and 0.013, respectively). It is worth noting that F1/ɑ/ decreased in 11 and F2/ɑ/ decreased in 10 of the 14 subjects. CONCLUSION The application of RME in the treatment of maxillary constriction leads to a significant lowering of the first and second formants for the vowel /ɑ/ in most subjects. Subjects undergoing rapid maxillary application should be aware of the potential change in voice quality especially in case of professional voice users.

Maxillary arch dimensions associated with acoustic parameters in prepubertal children

OBJECTIVES To evaluate the association between maxillary arch dimensions and fundamental frequency and formants of voice in prepubertal subjects. MATERIALS AND METHODS Thirty-five consecutive prepubertal patients seeking orthodontic treatment were recruited (mean age = 11.41 ± 1.46 years; range, 8 to 13.7 years). Participants with a history of respiratory infection, laryngeal manipulation, dysphonia, congenital facial malformations, or history of orthodontic treatment were excluded. Dental measurements included maxillary arch length, perimeter, depth, and width. Voice parameters comprising fundamental frequency (f0_sustained), Habitual pitch (f0_count), Jitter, Shimmer, and different formant frequencies (F1, F2, F3, and F4) were measured using acoustic analysis prior to initiation of any orthodontic treatment. Pearsons correlation coefficients were used to measure the strength of associations between different dental and voice parameters. Multiple linear regressions were computed for the predictions of different dental measurements. RESULTS Arch width and arch depth had moderate significant negative correlations with f0 ( r = -0.52; P = .001 and r = -0.39; P = .022, respectively) and with habitual frequency ( r = -0.51; P = .0014 and r = -0.34; P = .04, respectively). Arch depth and arch length were significantly correlated with formant F3 and formant F4, respectively. Predictors of arch depth included frequencies of F3 vowels, with a significant regression equation ( P-value < .001; R2 = 0.49). Similarly, fundamental frequency f0 and frequencies of formant F3 vowels were predictors of arch width, with a significant regression equation ( P-value < .001; R2 = 0.37). CONCLUSIONS There is a significant association between arch dimensions, particularly arch length and depth, and voice parameters. The formant most predictive of arch depth and width is the third formant, along with fundamental frequency of voice.

Association Between Facial Length and Width and Fundamental Frequency

OBJECTIVE This study aimed to evaluate the association between facial width and length and fundamental frequency (F0) and habitual frequency. STUDY DESIGN Prospective cross-sectional study. SUBJECTS A total of 50 subjects (35 females;15 males) were included in this study. METHODS Lateral and posteroanterior cephalometric measurements included: facial height (N-Me); widths of the maxilla (J-J), mandible (AG-AG), and face (Zyg-Zyg); ratios J-J to AG-AG, N-Me to Zyg-Zyg, and lower face to total face heights. All subjects underwent acoustic analysis using Visi-Pitch IV. Sample was stratified according to age and gender. RESULTS In the total group (mean age: 14.19±6.49 years; range 6-35 years), a significantly moderate negative correlation existed between Zyg-Zyg, J-J, and AG-AG, and F0 and habitual pitch. Similarly, N-Me moderately correlated with habitual pitch. In males, there was a significant moderate negative correlation between Zyg-Zyg and J-J, and habitual pitch, and between J-J and F0 (-0.571;p=0.026). In females, a significant moderate correlation existed between Zyg-Zyg and AG-AG, and habitual pitch, and between AG-AG and F0 (-0.347;p=0.041). In the prepubertal group (n=25), a negative moderate correlation occurred between J-J and AG-AG, N-Me and habitual frequency, and between J-J and F0 (-0.407;p=0.043). In the postpubertal group, there was a significant moderate correlation only between AG-AG and F0 (-0.403;p=0.046). CONCLUSION Facial length correlates significantly with habitual frequency, and facial width correlates significantly with both F0 and habitual pitch. A larger sample of adult subjects is needed to substantiate this conclusion.