Multitaper Spectrum Analysis of Consonants Produced by Patients With Dentofacial Disharmonies.

PURPOSE: This study investigates differences in American English consonants produced by patients who present with various dentofacial disharmonies (DFDs), including severe overbites (Class II), underbites (Class III), and anterior open bites. Previous studies have found that patients with these malocclusion types all produce lingual sibilants and plosives with increased spectral center of gravity and increased spectral variance relative to controls. This result is puzzling since some DFD groups differ from controls in opposite ways, and it is also difficult to interpret because spectral moment measures are affected by a wide range of speech and nonspeech factors. METHOD: To better understand the articulatory basis of these differences, we apply articulatorily interpretable spectral measures derived from multitaper spectra. RESULTS: We find that all groups of DFD patients produce /s ʃ t tʃ/ with midfrequency spectral peaks that are less prominent than those of the control group, but peak frequency measures are largely the same across all groups. CONCLUSION: We conclude that the DFD patients differ more in sibilant noise source properties than in front cavity filter properties.

Impacts of Development, Dentofacial Disharmony, and Its Surgical Correction on Speech: A Narrative Review for Dental Professionals.

Speech is a communication method found only in humans that relies on precisely articulated sounds to encode and express thoughts. Anatomical differences in the maxilla, mandible, tooth position, and vocal tract affect tongue placement and broadly influence the patterns of airflow and resonance during speech production. Alterations in these structures can create perceptual distortions in speech known as speech sound disorders (SSDs). As craniofacial development occurs, the vocal tract, jaws, and teeth change in parallel with stages of speech development, from babbling to adult phonation. Alterations from a normal Class 1 dental and skeletal relationship can impact speech. Dentofacial disharmony (DFD) patients have jaw disproportions, with a high prevalence of SSDs, where the severity of malocclusion correlates with the degree of speech distortion. DFD patients often seek orthodontic and orthognathic surgical treatment, but there is limited familiarity among dental providers on the impacts of malocclusion and its correction on speech. We sought to review the interplay between craniofacial and speech development and the impacts of orthodontic and surgical treatment on speech. Shared knowledge can facilitate collaborations between dental specialists and speech pathologists for the proper diagnosis, referral, and treatment of DFD patients with speech pathologies.

Impacts of anterior-posterior jaw disproportions on speech of dentofacial disharmony patients.

BACKGROUND/OBJECTIVES: Articulation problems impact communication, development, and quality of life, and are diagnosed in 73-87% of patients with Class II Dentofacial Disharmony (DFD). We evaluated whether differences exist in stop (/t/ or/k/), fricative (/s/ or/ʃ/), and affricate (/tʃ/) consonant sounds of Class II DFD subjects, and whether extent of malocclusion correlates with severity of speech distortion. We hypothesized that Class II patients display milder distortions than Class III and anterior open bite (AOB), as Class II patients can posture into a Class I occlusion. MATERIALS/METHODS: Audio and orthodontic records were collected from DFD patients (N = 53-Class II, 102-Class III, 72-Controls) who were pursuing orthodontics and orthognathic surgery. A speech pathologist perceptually scored speech. Acoustic differences in recordings were measured using Spectral Moment Analysis. RESULTS: When Class II subjects were compared to controls, significant differences were found for the centroid frequency (M1) of the /s/ sound and the spectral spread (M2) of /t/, /tʃ/, and /s/ sounds, with pairwise significance for controls relative to Class II AOB and all Class II subjects. Class II AOB subjects had higher M1 and M2 values than patients with Class II closed bites and Class I controls for most sounds. When comparing across anterior-posterior (AP) groups, differences exist between controls, Class II and III DFD subjects for M1 of /t/, /tʃ/, and/ʃ/ and M2 for /t/, /tʃ/, /s/, and /ʃ/ sounds. Using linear regression, correlations between Class II and III severity and spectral measures were found for /t/ and /tʃ/ sounds. CONCLUSIONS/IMPLICATIONS: Class II and III patients have a higher prevalence of qualitative distortions and spectral changes in consonants compared to controls, but Class II spectral shifts are smaller and affect fewer sounds than in Class III and AOB cohorts. Linear correlations between AP discrepancy and spectral change suggest causation and that treatment may improve articulation problems.

DENTOFACIAL DISHARMONY PATIENTS' SIBILANTS DIFFER FROM CONTROLS' MORE IN SOURCE THAN FILTER PROPERTIES.

This study uses multitaper spectral analysis to examine the differences in consonants produced by patients who present with different dentofacial disharmonies (DFD) including severe overbites (Class II), underbites (Class III) and anterior open bites. Previous studies have found that patients with these malocclusion types all produce sibilants and plosives with increased spectral center of gravity and increased spectral spread relative to controls. This result is puzzling since some DFD groups differ from controls in opposite ways. To better understand the articulatory basis of these differences, we apply several spectral shape measures and find that all groups of DFD patients produce /s ʃ t tʃ/ with mid-frequency spectral peaks that are less prominent than those of the control group, but peak frequency measures are largely the same across all groups. This indicates that the DFD patients differ more in sibilant noise source than front cavity size.1.

Impacts of Skeletal Anterior Open Bite Malocclusion on Speech.

Introduction: Articulation problems are seen in 80-90% of dentofacial deformity (DFD) subjects compared with 5% of the general population, impacting communication and quality of life, but the causal link is unclear. We hypothesize there are both qualitative (perceptual) and quantitative (spectral) differences in properties of stop (/t/ or /k/), fricative (/s/ or /∫/), and affricate (/t∫/) consonant sounds and that severity of anterior open bite (AOB) jaw disharmonies correlates with degree of speech abnormality. Methods: To test our hypotheses, surgical orthodontic records and audio recordings were collected from DFD patients (n=39 AOB, 62 controls). A speech pathologist evaluated subjects and recordings were analyzed using spectral moment analysis (SMA) to measure sound frequency distortions. Results: Perceptually, there is a higher prevalence of auditory and visual speech distortions in AOB DFD patients when compared to controls. Quantitatively, a significant (p<0.01) increase in the centroid frequency (M1) was seen in the /k/, /t/, /t∫/, and /s/ sounds of AOB subjects compared to the controls. Using linear regression, correlations between AOB skeletal severity and spectral distortion were found for /k/ and /t/ sounds. Conclusions: A higher prevalence of qualitative distortion and significant quantitative spectral distortions in consonant sounds were seen in AOB patients compared to controls. Additionally, severity of skeletal AOB is correlated with degree of distortion for consonant sounds. These findings provide insight into how the surgical and/or orthodontic treatment of AOB may impact speech.

Active Unilateral Condylar Hyperplasia Treated With Simultaneous Condylectomy and Orthognathic Surgery: A Clinical Report.

PURPOSE: To review and report the demographic and diagnostic data in a population with active unilateral condylar hyperplasia. The surgical intervention, sequencing of surgery, and treatment outcomes, including a quality-of-life survey, are described. MATERIALS AND METHODS: Eighty patients were diagnosed with active disease. Demographic, treatment, and treatment outcomes were assessed. Quality of life was assessed by a 21-question questionnaire. RESULTS: Women were affected more frequently than men (W - 52; 65%; P = .008). Hemimandibular elongation (HE) (49; 61%; P - .004) occurred more frequently than hemimandibular hyperplasia (HH) (24; 30%) and HH-HE (7; 9%). Right side was affected more than left (R - 49; 61%; P - .003) overall, and when stratified. All racial groups were represented. Of the 80 patients in the sample, 80 (100%) underwent condylectomy on the side of active growth, 70 (87%) underwent bimaxillary osteotomies, 53 patients (66%) had single-piece maxillary osteotomies, 17 (21%) underwent segmental maxillary osteotomies, and 38 (48%) genioplasties were performed. Four patients (5%) underwent a second operation within a year of the first surgery to adjust the position of the mandible. Four (5%) facial nerve deficits were recorded. Class I cuspid occlusion was achieved with coincident maxillary and mandibular midlines and resolution of crossbite in 70 (88%) patients. Twenty three of the 24 respondents (96%) reported that they were satisfied with the treatment. CONCLUSIONS: Both HH and HE are diagnosed through clinical and radiographic examinations. Our results showed that HE occurs more frequently, all deformity subclassifications occur more frequently in females, the majority present in adolescence, and all racial groups are affected. The right side predominated. This study suggests that simultaneous condylectomy and orthognathic surgery provides predictable and stable outcomes for patients with active unilateral condylar hyperplasia and associated dentofacial deformities with an improvement in quality of living.

Orthognathic speech pathology: impacts of Class III malocclusion on speech.

INTRODUCTION: Patients with dentofacial disharmonies (DFDs) seek orthodontic care and orthognathic surgery to address issues with mastication, esthetics, and speech. Speech distortions are seen 18 times more frequently in Class III DFD patients than the general population, with unclear causality. We hypothesize there are significant differences in spectral properties of stop (/t/ or /k/), fricative (/s/ or /ʃ/), and affricate (/tʃ/) consonants and that severity of Class III disharmony correlates with the degree of speech abnormality. METHODS: To understand how jaw disharmonies influence speech, orthodontic records and audio recordings were collected from Class III surgical candidates and reference subjects (n = 102 Class III, 62 controls). A speech pathologist evaluated subjects and recordings were quantitatively analysed by Spectral Moment Analysis for frequency distortions. RESULTS: A majority of Class III subjects exhibit speech distortions. A significant increase in the centroid frequency (M1) and spectral spread (M2) was seen in several consonants of Class III subjects compared to controls. Using regression analysis, correlations between Class III skeletal severity (assessed by cephalometric measures) and spectral distortion were found for /t/ and /k/ phones. CONCLUSIONS: Class III DFD patients have a higher prevalence of articulation errors and significant spectral distortions in consonants relative to controls. This is the first demonstration that severity of malocclusion is quantitatively correlated with the degree of speech distortion for consonants, suggesting causation. These findings offer insight into the complex relationship between craniofacial structures and speech distortions.

Mandibular condylar remodeling characteristics after simultaneous condylectomy and orthognathic surgery.

INTRODUCTION: The objectives of this study were to evaluate postsurgical condylar remodeling using a radiographical interpretation, quantify condylar volumetric asymmetry, and assess soft tissue symmetry after simultaneous unilateral high condylectomy and bimaxillary osteotomies. METHODS: Sixteen patients diagnosed with unilateral condylar hyperplasia underwent unilateral high condylectomy and orthognathic surgery to correct skeletal and facial asymmetries. Cone-beam computed tomography scans were acquired before and 1-year after surgery. A radiographic consensus was evaluated for signs of reparative or degenerative changes. The condyles were mirrored and registered for assessment of volumetric and morphologic asymmetry. Soft tissue symmetry was evaluated by measurement of the distance of soft tissue pogonion from the skeletal midsagittal plane. RESULTS: Patients who undergo unilateral high condylectomy and orthognathic surgery present radiographic signs suggestive of degenerative changes, including sclerosis, osteophytes, flattening, and erosion in both the surgical and nonsurgical condyles (P ≤0.01). There was an average volumetric improvement of 531.9 ± 662.3 mm3 1-year postsurgery (P = 0.006). Soft tissue symmetry improved in all patients, with an average improvement of 65.8% (4.0 mm ± 2.6 mm, P ≤ 0.01). There was no correlation between the change in condylar volumetric asymmetry and the stability of the soft tissue correction. CONCLUSIONS: High condylectomy for the correction of a skeletal asymmetry in patients with condylar hyperplasia successfully reduces the volumetric asymmetry between the condyles. Postsurgical dysmorphic remodeling and degenerative changes were noted in both the surgical and nonsurgical condyles. Despite remarkable changes and remaining joint asymmetry, the soft tissue correction is stable 1-year postsurgery.

Severe bleeding from a duodenal ulcer after orthognathic surgery: a case report.

Chronic non-steroidal anti-inflammatory drug use is strongly associated with peptic ulcer disease, and corticosteroid use has also been cited as a risk factor. Both are frequently prescribed for short courses after orthognathic surgery to minimize edema. It appears that no cases of severe bleeding from a duodenal ulcer have been reported during the postoperative period after orthognathic surgery. This case describes a patient who experienced this severe bleeding despite having no risk factors.

Changes in scleral exposure following modified Le Fort III osteotomy.

OBJECTIVE: The Kufner modified Le Fort III osteotomy (LFIII) can be used to address midface deficiency, which is often accompanied by excessive scleral exposure. The purpose of this project is to analyze the changes in scleral exposure after a LFIII. METHODS: Thirteen patients with midface hypoplasia were treated with LFIII. Scleral surface area (SSA) was determined by pixel count and the distance from the inferior eyelid margin to the center of the pupil (MED) was measured pre- and postoperatively. Intraclass correlation coefficients were calculated to assess measurement reliability and repeated measures analysis of variance (ANOVA) were determined to assess systematic difference among the replicates. RESULTS: The interquartile range for change in SSA ranged from -31% to -7%, median 20% (P = .002) and the interquartile range for change in MED ranged from -21% to -12%, median -18% (P = .0002). CONCLUSIONS: SSA and MED can be reliably determined using the aforementioned method. The LFIII decreases scleral exposure.

Postdischarge Nausea and Vomiting Remains Frequent After Le Fort I Osteotomy Despite Implementation of a Multimodal Antiemetic Protocol Effective in Reducing Postoperative Nausea and Vomiting.

PURPOSE: To assess the prevalence of postdischarge nausea and vomiting (PDNV) after Le Fort I osteotomy with and without the use of a multimodal antiemetic protocol shown to decrease postoperative nausea and vomiting (PONV). MATERIALS AND METHODS: Consecutive patients undergoing Le Fort I osteotomy with or without additional procedures at a single academic institution formed the intervention cohort for an institutional review board-approved prospective clinical trial with a retrospective comparison group. The intervention cohort was managed with a multimodal antiemetic protocol. The comparison group consisted of consecutive patients who underwent similar surgical procedures at the same institution before protocol implementation. All patients were asked to complete a postdischarge diary documenting the occurrence of nausea and vomiting. Those who completed the diaries were included in this analysis. Data were analyzed with the Fisher exact test and the Wilcoxon rank sum test. A P value less than .05 was considered significant. RESULTS: Diaries were completed by 85% of patients in the intervention group (79 of 93) and 75% of patients in the comparison group (103 of 137). Patients in the intervention (n = 79) and comparison (n = 103) groups were similar in the proportion of patients with validated risk factors for PDNV, including female gender, history of PONV, age younger than 50 years, opioid use in the postanesthesia care unit (PACU), and nausea in the PACU (P = .37). The prevalence of PDNV was unaffected by the antiemetic protocol. After discharge, nausea was reported by 72% of patients in the intervention group and 60% of patients in the comparison group (P = .13) and vomiting was reported by 22% of patients in the intervention group and 29% of patients in the comparison group (P = .40). CONCLUSION: Modalities that successfully address PONV after Le Fort I osteotomy might fail to affect PDNV, which is prevalent in this population. Future investigation will focus on methods to minimize PDNV.

Unilateral mydriasis after maxillary osteotomy: a case series and review of the literature.

PURPOSE: To present 4 cases of unilateral mydriasis associated with orthognathic surgery and to review the differential diagnosis and management related to this condition. MATERIALS AND METHODS: Four cases of unilateral mydriasis associated with orthognathic surgery were identified from the authors' institutional experience. All maxillary osteotomies performed by the authors' department from 2001 to 2013 were identified based on Current Procedural Terminology codes; 4 cases of unilateral mydriasis were found. Cases are presented and the literature is reviewed. RESULTS: Two male and 2 female patients with an age range of 16 to 34 years developed unilateral mydriasis after maxillary osteotomy; the estimated prevalence is 0.004%. Although the precise cause can be difficult to determine, in this series 1 case was attributable to swelling affecting contents of the superior orbital fissure, 1 was related to edema or medications, and 2 were pharmacologically induced. CONCLUSION: Although rare, a review of the differential diagnosis for and management of unilateral mydriasis associated with orthognathic surgery is pertinent to those who perform corrective jaw surgery.

Multimodal protocol reduces postoperative nausea and vomiting in patients undergoing Le Fort I osteotomy.

PURPOSE: To assess the impact of a multimodal antiemetic protocol on postoperative nausea and vomiting (PONV) after Le Fort I osteotomy. MATERIALS AND METHODS: Consecutive patients undergoing Le Fort I osteotomy with or without additional procedures at a single academic institution were recruited as the intervention cohort for an institutional review board-approved prospective clinical trial with a retrospective comparison group. The intervention cohort was managed with a multimodal antiemetic protocol, including total intravenous anesthesia; prophylactic ondansetron, steroids, scopolamine, and droperidol; gastric decompression at surgery end; opioid-sparing analgesia; avoidance of morphine and codeine; prokinetic erythromycin; and fluids at a minimum of 25 mL/kg. The comparison group consisted of consecutive patients from a larger study who underwent similar surgical procedures before protocol implementation. Data, including occurrence of PONV, were extracted from medical records. Data were analyzed in bivariate fashion with the Fisher exact and Wilcoxon rank-sum tests. Logistic regression was used to compare the likelihood of nausea and vomiting in the 2 cohorts after controlling for demographic and surgical characteristics. A P value less than .05 was considered significant. RESULTS: The intervention (n = 93) and comparison (n = 137) groups were similar in gender (58% and 65% female patients; P = .29), race (72% and 71% Caucasian; P = .85), age (median, 19 and 20 years old; P = .75), proportion of patients with known risk factors for PONV (P = .34), percentage undergoing bimaxillary surgery (60% for the 2 groups), and percentage for whom surgery time was longer than 180 minutes (63% and 59%; P = .51). Prevalence of postoperative nausea was significantly lower in the intervention group than in the comparison group (24% vs 70%; P < .0001). Prevalence of postoperative vomiting was likewise significantly lower in the intervention group (11% vs 28%; P = .0013). The likelihood that patients in the comparison group would develop nausea was 8.9 and that for vomiting was 3.7 times higher than in the intervention group. CONCLUSION: This multimodal protocol was associated with substantially decreased prevalence of PONV in patients undergoing Le Fort I osteotomy.

Long-term 3-dimensional stability of mandibular advancement surgery.

PURPOSE: To evaluate 3-dimensional changes in the position of the condyles, rami, and chin from 1 to 3 years after mandibular advancement surgery. MATERIALS AND METHODS: This prospective observational study used pre- and postoperative cone-beam computed tomograms of 27 subjects with skeletal Class II jaw relation and normal or deep overbite. An automatic technique of cranial base superimposition was used to assess positional and bone remodeling changes that were visually displayed and quantified using 3-dimensional color maps. Analysis of covariance with presence of genioplasty, age at time of surgery, and gender as explanatory variables was used to estimate and test adjusted mean changes for each region of interest. RESULTS: The chin rotated downward and backward 1 to 3 years after surgery. Changes of at least 2 mm were observed in 17% of cases. Mandibular condyles presented with displacements or bone remodeling of at least 2 mm on the anterior surface (21% of cases on the left side and 13% on the right), superior surface (8% on right and left sides), and lateral poles (17% on left side and 4% on right). Posterior borders of the rami exhibited symmetric lateral or rotational displacements in 4% of cases. CONCLUSION: In the hierarchy of surgical stability, mandibular advancement surgery is considered one of the most stable surgical procedures. However, 1 to 3 years after surgery, approximately 20% of patients had 2- to 4-mm changes in horizontal and vertical chin positions or changes in condylar position and adaptive bone remodeling.

Changes in the pattern of patients receiving surgical-orthodontic treatment.

INTRODUCTION: The characteristics of patients who seek and accept orthognathic surgery appear to be changing over time but have not been well documented in the 21st century. METHODS: Records for patients who had orthognathic surgery at the University of North Carolina from 1996 to 2000 and from 2006 to 2010 were reviewed to collect data for changes in the prevalence of patients with mandibular deficiency (Class II), maxillary deficiency or mandibular prognathism (Class III), long face, and asymmetry problems. The changes were compared with those in previous time periods and at other locations. RESULTS: Between 1996 and 2000 and between 2006 and 2010, the percentage of Class III patients increased from 35% to 54%, and the percentage of Class II patients decreased from 59% to 41%, while the percentages for long face and asymmetry showed little change. The decrease in Class II patients was accentuation of a long-term trend; the increase in Class III patients occurred only after the turn of the century. CONCLUSIONS: A similar but less-marked change has been noted at some but not all other locations in the United States. It appears to be related primarily to an increase in the numbers of African Americans, Native Americans, Hispanics, and Asians who now are seeking surgical treatment, but it also has been affected by changes in where orthognathic surgery is performed, decisions by third-party payers (insurance and Medicaid) about coverage for treatment, and the availability of nonsurgical orthodontic treatment options for Class II patients.

Orbital anatomy for the surgeon.

An anatomic description of the orbit and its contents and the eyelids directed toward surgeons is the focus of this article. The bone and soft tissue anatomic nuances for surgery are highlighted, including a section on osteology, muscles, and the orbital suspensory system. Innervation and vascular anatomy are also addressed.

The effect of preoperative recombinant erythropoietin on postoperative hematocrit level after orthognathic surgery.

PURPOSE: To compare the postoperative red cell mass as indicated by the hematocrit value of orthognathic surgery patients given iron supplementation and a single preoperative dose of erythropoietin alpha (EPO) and patients who did not receive either EPO or iron supplementation. PATIENTS AND METHODS: Subjects who had a Le Fort I osteotomy (LFI) or a combination of LFI and bilateral sagittal split osteotomy between 2005 and 2008 and were aged at least 13 years were included. Subjects were excluded if they had a history of maxillofacial trauma, a craniofacial syndrome, or a major systemic medical condition. Subjects either had EPO administered with iron supplements before surgery (surgeon A protocol) or received neither (surgeon B protocol). Venous blood samples were taken, in accordance with clinic protocol, before surgery (before administration of EPO) and on postoperative day 1. Multiple linear regression with backward selection was used to analyze the change in hematocrit value. Explanatory variables included group, preoperative hematocrit level, age, gender, length of surgery, blood loss, and crystalloid (fluid replacement) volume. RESULTS: The study included 178 eligible patients: 86 (48%) had a combination of LFI and bilateral sagittal split osteotomy and 92 (52%) had an isolated LFI. Of the patients, 114 (64%) had EPO/iron supplements administered before surgery whereas 64 did not. The mean change in hematocrit level as an indicator of the change in red cell mass was statistically significantly different (P = .01) for the subjects who received preoperative administration of EPO with iron supplementation compared with those who did not receive EPO plus iron. The administration of EPO plus iron was protective: the decrease in hematocrit level after surgery was smaller for subjects in the EPO group even after we controlled for age, gender, preoperative hematocrit level, length of surgery, blood loss, and crystalloid (fluid replacement) volume. CONCLUSIONS: A single preoperative dose of erythropoietin with iron supplementation resulted in a smaller decrease, on average, in postoperative red cell mass as indicated by hematocrit value in patients with complicated orthognathic surgery procedures.