The relationship between upper airways and craniofacial morphology studied in 3D. A CBCT study

OBJECTIVES

To assess whether morphology and dimension of the upper airway differ between patients characterized by various craniofacial morphology.

SETTING AND SAMPLE POPULATION

Ninety young adult patients from the Postgraduate Clinic, Section of Orthodontics, Department of Dentistry, Health, Aarhus University, Denmark, with no obvious signs of respiratory diseases and no previous adeno-tonsillectomy procedures. Thirty patients were characterized as Class I (-0.5 < ANB < 4.5), 30 as Class II (ANB > 4.5), and 30 as Class III (ANB < -0.5).

MATERIAL AND METHODS

Cone-beam computed tomography (CBCT) scans obtained in a supine position for all patients. Cephalometric landmarks were identified in 3D. Sagittal and transversal dimensions, cross sections, and partial and total volumes of the upper airway were correlated with the cephalometric measurements in all three planes of space. The cross-sectional minimal area of the upper airway was assessed as well.

RESULTS

No statistical significant relationships between dimension and morphology of upper airways and skeletal malocclusion were found.

CONCLUSION

Differences in craniofacial morphology as identified by the sagittal jaw relationship were not correlated with variation in upper airway volumes. A clinical significant relation was detected between minimal area and total upper airway volume.

Timing of Pharyngeal Swallow Events in Chagas' Disease

Background

Esophageal involvement by Chagas’ disease causes a significative decrease in the number of neurons of the esophageal myenteric plexus, causing an impairment of esophageal motility with the same alterations described in primary esophageal achalasia. There is also a longer duration of pharyngeal transit, which might be consequent of the involvement of the central control of swallowing by the disease, or an adaptation of the pharynx to the difficult bolus transit through the esophagus, which could contribute to the complaint of dysphagia.

Methods

We studied, by videofluoroscopy, the sequence and timings of pharyngeal bolus transit in 16 patients with esophageal involvement by Chagas’ disease and 12 healthy volunteers. Each subject swallowed in duplicate 5 mL and 10 mL of liquid and paste boluses.

Results

There was no difference between Chagas’ disease patients and normal volunteers in the sequence and timing of events associated with pharyngeal bolus flow, for liquid and paste boluses, and for 5 mL and 10 mL.

Conclusion

The timing and sequence of swallow pharyngeal events of patients with Chagas’ disease do not differ from that of control subjects, which suggested that the central control of swallowing is not impaired by the disease.

CEH-28 activates dbl-1 expression and TGF-β signaling in the C. elegans M4 neuron

M4 is a multifunctional neuron in the Caenorhabditis elegans pharynx that can both stimulate peristaltic contractions of the muscles in the pharyngeal isthmus and function systemically to regulate an enhanced sensory response under hypoxic conditions. Here we identify a third function for M4 that depends on activation of the TGF-β family gene dbl-1 by the homeodomain transcription factor CEH-28. dbl-1 is expressed in M4 and a subset of other neurons, and we show CEH-28 specifically activates dbl-1 expression in M4. Characterization of the dbl-1 promoter indicates that CEH-28 targets an M4-specific enhancer within the dbl-1 promoter region, while expression in other neurons is mediated by separate regulatory sequences. Unlike ceh-28 mutants, dbl-1 mutants do not exhibit M4 synaptic and signaling defects. Instead, both ceh-28 and dbl-1 mutants exhibit morphological defects in the g1 gland cells located adjacent to M4 in the pharynx, and these defects can be partially rescued by M4-specific expression of dbl-1 in these mutants. Identical gland cell defects are observed in sma-6 and daf-4 mutants defective in the receptor for DBL-1, but they are not observed in sma-2 and sma-3 mutants lacking the R-Smads functioning downstream of this receptor. Together these results identify a novel neuroendocrine function for M4 and provide evidence for an R-Smad-independent mechanism for DBL-1 signaling in C. elegans.

Grainyhead-like 3 regulation of endothelin-1 in the pharyngeal endoderm is critical for growth and development of the craniofacial skeleton

Craniofacial development is a highly conserved process that requires complex interactions between neural crest cells (NCCs) and pharyngeal tissues derived from all three germ layers. Signals emanating from the pharyngeal endoderm drive differentiation of NCCs into craniofacial cartilage, and disruption of this process underpins several human craniofacial defects (CFD). Here, we demonstrate that morpholino (MO)-mediated knockdown in zebrafish of the highly conserved transcription factor grainyhead-like 3 (grhl3), which is selectively expressed in the pharyngeal endoderm, leads to severe hypoplasia of the lower jaw cartilages. Phylogenetic analysis of conserved grhl-binding sites in gene regulatory regions identified endothelin-1 (edn1) as a putative direct grhl3 target gene, and this was confirmed by chromatin precipitation (ChIP) assays in zebrafish embryos. Injection of sub-phenotypic concentrations of MOs targeting both grhl3 and edn1 induced jaw abnormalities, and injection of edn1 mRNA into grhl3-morphants rescued both pharyngeal expression of the downstream effectors of edn1, and jaw cartilage formation. This study sheds new light on the role of endodermal endothelin-1 in vertebrate jaw development, and highlights potential new genetic defects that could underpin human CFD.

Roles for FGF in lamprey pharyngeal pouch formation and skeletogenesis highlight ancestral functions in the vertebrate head

A defining feature of vertebrates (craniates) is a pronounced head supported and protected by a cellularized endoskeleton. In jawed vertebrates (gnathostomes), the head skeleton is made of rigid three-dimensional elements connected by joints. By contrast, the head skeleton of modern jawless vertebrates (agnathans) consists of thin rods of flexible cellular cartilage, a condition thought to reflect the ancestral vertebrate state. To better understand the origin and evolution of the gnathostome head skeleton, we have been analyzing head skeleton development in the agnathan, lamprey. The fibroblast growth factors FGF3 and FGF8 have various roles during head development in jawed vertebrates, including pharyngeal pouch morphogenesis, patterning of the oral skeleton and chondrogenesis. We isolated lamprey homologs of FGF3, FGF8 and FGF receptors and asked whether these functions are ancestral features of vertebrate development or gnathostome novelties. Using gene expression and pharmacological agents, we found that proper formation of the lamprey head skeleton requires two phases of FGF signaling: an early phase during which FGFs drive pharyngeal pouch formation, and a later phase when they directly regulate skeletal differentiation and patterning. In the context of gene expression and functional studies in gnathostomes, our results suggest that these roles for FGFs arose in the first vertebrates and that the evolution of the jaw and gnathostome cellular cartilage was driven by changes developmentally downstream from pharyngeal FGF signaling.

An association between Helicobacter pylori and upper respiratory tract disease: Fact or fiction?

Helicobacter pylori (H. pylori) is a major cause of chronic gastritis and gastric ulcers and considerable evidence supports the notion that infection with this bacterium is also associated with gastric malignancy in addition to various other conditions including pulmonary, vascular and autoimmune disorders. Gastric juice infected with H. pylori might play an important role in upper respiratory tract infection. Although direct and/or indirect mechanisms might be involved in the association between H. pylori and upper respiratory tract diseases, the etiological role of H. pylori in upper respiratory tract disorders has not yet been fully elucidated. Although various studies over the past two decades have suggested a relationship between H. pylori and upper respiratory tract diseases, the findings are inconsistent. The present overview describes the outcomes of recent investigations into the impact of H. pylori on upper respiratory tract and adjacent lesions.

Facilitation of the swallowing reflex with bilateral afferent input from the superior laryngeal nerve

To determine the cooperative effect of laryngeal afferent signals on the swallowing reflex, we examined whether afferent signals originating from the left and right superior laryngeal nerve (SLN) modulates elicitation of the swallowing reflex in urethane-anesthetized rats. Mylohyoid electromyographic activity was recorded to quantify the swallowing reflex. The onset latency of the swallowing reflex and the time intervals between successive swallows were used to quantify and compare the effects of unilateral and bilateral electrical stimulations of the SLN. The mean latency of the first swallow and the mean time interval between swallows evoked with low frequency stimulation were both significantly different between unilateral and bilateral stimulations of the SLN. These findings suggest that facilitatory effect of afferent signals originating from the SLN bilaterally increase the motoneuronal activity in the medullary swallowing center and enhance the swallowing reflex.

Coordination of cough and swallow: a meta-behavioral response to aspiration

Airway protections is the prevention and/or removal of material by behaviors such as cough and swallow. We hypothesized these behaviors are coordinated to respond to aspiration. Anesthetized animals were challenged with simulated aspiration that induced both coughing and swallowing. Electromyograms of upper airway and respiratory muscles together with esophageal pressure were recorded to identify and evaluate cough and swallow. During simulated aspiration, both cough and swallow intensity increased and swallow duration decreased consistent with rapid pharyngeal clearance. Phase restriction between cough and swallow was observed; swallow was restricted to the E2 phase of cough. These results support three main conclusions: 1) the cough and swallow pattern generators are tightly coordinated so as to generate a protective meta-behavior; 2) the trachea provides feedback on swallow quality, informing the brainstem about aspiration incidences; and 3) the larynx and upper esophageal sphincter act as two separate valves controlling the direction of positive and negative pressures from the upper airway into the thorax.

Coordination of cough and swallow: a meta-behavioral response to aspiration

Airway protections is the prevention and/or removal of material by behaviors such as cough and swallow. We hypothesized these behaviors are coordinated to respond to aspiration. Anesthetized animals were challenged with simulated aspiration that induced both coughing and swallowing. Electromyograms of upper airway and respiratory muscles together with esophageal pressure were recorded to identify and evaluate cough and swallow. During simulated aspiration, both cough and swallow intensity increased and swallow duration decreased consistent with rapid pharyngeal clearance. Phase restriction between cough and swallow was observed; swallow was restricted to the E2 phase of cough. These results support three main conclusions: 1) the cough and swallow pattern generators are tightly coordinated so as to generate a protective meta-behavior; 2) the trachea provides feedback on swallow quality, informing the brainstem about aspiration incidences; and 3) the larynx and upper esophageal sphincter act as two separate valves controlling the direction of positive and negative pressures from the upper airway into the thorax.

Upper airway obstruction in Norwich Terriers: 16 cases

BACKGROUND

Norwich Terriers have grown increasingly popular as show animals and pets, and awareness of respiratory problems within the breed is growing.

OBJECTIVE

To describe components of obstructive upper airway syndrome in a nonbrachycephalic terrier breed.

ANIMALS

Sixteen Norwich Terriers; 12 with and 4 without clinical signs of respiratory disease.

METHODS

Prospective case series. Physical and laryngoscopic examinations were performed by 1 investigator in all dogs. Medical and surgical interventions were summarized and results of follow-up examination or owner reports were recorded.

RESULTS

The study population was comprised of 9 females (6 intact) and 7 males (5 intact). Median age was 3.0 years (range, 0.5-11 years). Of 12 dogs presented for a respiratory complaint, physical examination was normal in 4 dogs. Laryngoscopic examination was abnormal in 11/12 dogs with redundant supra-arytenoid folds, laryngeal collapse, everted laryngeal saccules, and a narrowed laryngeal opening in most. Of 4 dogs lacking clinical signs, all had normal physical examination; however, 3/4 dogs had similar appearance of the larynx to dogs with clinical signs. Response to surgical intervention was minimal to moderate in all dogs.

CONCLUSIONS AND CLINICAL IMPORTANCE

Norwich Terriers suffer from an upper airway obstructive syndrome that differs from that encountered in brachycephalic breeds. Affected dogs are difficult to identify without laryngoscopic examination because of the lack of clinical signs and abnormalities in physical examination findings, despite severe airway obstruction. Care is warranted when anesthetizing Norwich Terriers because of the small size of the laryngeal opening.

Pregnancy is associated with a decrease in pharyngeal but not tracheal or laryngeal cross-sectional area: a pilot study using the acoustic reflection method

BACKGROUND

The risk of difficult upper airway access is increased during pregnancy, especially in labor. Changes in upper airway calibre have been poorly studied during pregnancy. The acoustic reflection method is a non-invasive technique that allows a longitudinal assessment of the cross-sectional area of the upper airway from the mouth to carina. We used this technique to evaluate upper airway calibre during normal pregnancy.

METHODS

We conducted a prospective, single centre, observational study with a clinical and upper airway acoustic reflection method evaluation of healthy women during the first, second and third trimesters of pregnancy, and up to two days and one month after delivery.

RESULTS

Fifty women participated to the study. The mean pharyngeal cross-sectional area decreased between the first and third trimesters (P < 0.001) with no significant change of the minimal and mean tracheal cross-sectional areas. The Mallampati score increased during pregnancy between the first and third trimesters (P< 0.001).

CONCLUSION

Using measurements with the acoustic reflection method, normal pregnancy is associated with a significant reduction in the cross-sectional area of the pharynx and a concomitant increase in the Mallampati score. No change was observed in the minimal and mean tracheal cross-sectional areas.

Pterygoid hamulus bursitis as a cause of craniofacial pain: a case report

Pain on the soft palate and pharynx can originate in several associated structures. Therefore, diagnosis of patients who complain of discomfort in these areas may be difficult and complicated. Pterygoid hamulus bursitis is a rare disease showing various symptoms in the palatal and pharyngeal regions. As such, it can be one of the reported causes of pain in these areas. Treatment of hamular bursitis is either conservative or surgical. If the etiologic factor of bursitis is osteophytic formation on the hamulus or hypertrophy of the bursa, resection of the hamulus is usually the preferred surgical treatment. We report on a case of bursitis that was managed successfully by surgical treatment and a review of the literature.

Observable Laryngopharyngeal Lesions during the Upper Gastrointestinal Endoscopy

Regardless of outstanding developments in the endoscopic field, laryngopharyngeal lesions are generally considered as a field of otolaryngology, and thus it is thought that not a lot of gastrointestinal endoscopists commonly take interest in these lesions during the upper gastrointestinal endoscopic examinations. Therefore, here in this thesis, I reviewed the availability of upper gastrointestinal endoscopy in laryngopharyngeal area, normal structures of laryngopharynx, and the lesions that can be observed with the standard upper gastrointestinal endoscopic procedure.

Pharyngo-vertebral fistula secondary to cervical vertebral fracture in a patient with stab wound

Pharyngo-vertebral fistula (PVF) associated with cervical (C) spinal fracture is an extremely rare event that may lead to life-threatening infectious complications if not recognized promptly. Successful management of PVF depends on the physicians' awareness of the causes, prompt recognition of the symptoms and clinical findings, and immediate institution of treatment. I report a case of PVF after C3 vertebral body fracture that was initially neglected and subsequently developed into osteomyelitis involving adjacent vertebrae. On computed tomography and magnetic resonance imaging showed a PVF. Despite conservative care, spontaneous closure of the fistula was not achieved. Removal of PVF and surrounding granulation was achieved without any complication. To the best of my knowledge, PVF as a complication of C spine fracture has not hitherto been reported in the English literature.

Utility and stability of transnasal endoscopy for examination of the pharynx - a prospective study and comparison with transoral endoscopy

OBJECTIVE

Transnasal endoscopy may be used to observe the head and neck part readily without excessive reflexes. We aimed to evaluate the utility and stability of transnasal esophagogastroduodenoscopy (TN-EGD) in comparison with transoral EGD (TO-EGD) for observation of the pharynx.

STUDY DESIGN

Prospective study

METHODS

A total of 497 patients received unsedated TN-EGD with a 5.5 mm diameter endoscope or unsedated TO-EGD with endoscopes of 6.5 mm, 7.9 mm and 9.2 mm diameter. The rate of completion of pharyngeal observation and numbers of gag reflexes and cough reflexes were recorded.

RESULTS

TN-EGD was performed in 175 patients and TO-EGD was performed in 322 patients. Pharyngeal observation was completed in 173 patients (98.9%) in the TN-EGD group and 235 patients (73.2%) in the TO-EGD group, a significant difference (p<0.001). The TN-EGD group had a low rate of occurrence of gag reflex (0.57%), in contrast, 28.3% of the TO-EGD group had a gag reflex, a significant difference (p<0.01). Multivariable analyses revealed that the use of TN-EGD was the only predictive factor for completion of pharyngeal observation (p<0.0001).

CONCLUSIONS

TN-EGD is ideally suited to observation of the pharynx by unsedated EGD.

Upper respiratory tract and cutaneous diphtheria

With the global immunization programme of children there is a progressive decline in the number of diphtheria cases. It is a disease commonly affecting the children caused by Corynebacterium diphtheriae usually affecting the mucous membrane of the nose, pharynx or larynx. Cutaneous diphtheria is a rare entity. We present a rare case of cutaneous diphtheria in a 15-year-old boy with nasal pharyngeal and laryngeal involvement. The patient developed anaphylactic reaction to antidiphtheritic serum (ADS) during treatment, all of which were managed successfully.

Diagnostic utility of narrow-band imaging endoscopy for pharyngeal superficial carcinoma

AIM: To investigate the endoscopic features of pharyngeal superficial carcinoma and evaluate the utility of narrow-band imaging (NBI) for this disease.

METHODS: In the present prospective study, 335 patients underwent conventional white light (CWL) endoscopy and non-magnified/magnified NBI endoscopy, followed by an endoscopic biopsy, for 445 superficial lesions in the oropharynx and hypopharynx. The macroscopic appearance of superficial lesions was categorized as either elevated (< 5 mm in height), flat, or depressed (not ulcerous). Superficial carcinoma (SC) was defined as a superficial lesion showing high-grade dysplasia or squamous cell carcinoma on histology. The color, delineation, and macroscopic appearances of the lesions were evaluated by CWL endoscopy. The ratio of the brownish area/intervascular brownish epithelium (IBE), as well as microvascular proliferation, dilation, and irregularities, was determined by non-magnified/magnified NBI endoscopy. An experienced pathologist who was unaware of the endoscopic findings made the histological diagnoses. By comparing endoscopic findings with histology, we determined the endoscopic features of SC and evaluated the diagnostic utility of NBI.

RESULTS: The 445 lesions were divided histologically into two groups: a non-SC group, including non-neoplasia and low-grade dysplasia cases, and an SC group. Of the 445 lesions examined, 333 were classified as non-SC and 112 were classified as SC. There were no significant differences in age, gender, or the location of the lesions between the patients in the two groups. The mean diameter of the SC lesions was significantly greater than that of non-SC lesions (11.0 ± 7.6 mm vs 4.6 ± 3.6 mm, respectively, P < 0.001). Comparisons of CWL endoscopy findings for SC and non-SC lesions by univariate analysis revealed that the incidence of redness (72% vs 41%, respectively, P < 0.001) and a flat or depressed type of lesion (58% vs 44%, respectively, P = 0.013) was significantly higher in the SC group. Using non-magnified NBI endoscopy, the incidence of a brownish area was significantly higher for SC lesions (79% vs 57%, respectively, P < 0.001). On magnified NBI endoscopy, the incidence of IBE (68% vs 33%, P < 0.001) and microvascular proliferation (82% vs 51%, P < 0.001), dilation (90% vs 76%, P = 0.002), and irregularity (82% vs 31%, P < 0.001) was also significantly higher for the SC compared with the non-SC lesions. Multivariate analysis revealed that the incidence of redness (P = 0.022) on CWL endoscopy and IBE (P < 0.001) and microvascular irregularities (P < 0.001) on magnified NBI endoscopy was significantly higher in SC than non-SC lesions. Redness alone exhibited significantly higher sensitivity and significantly lower specificity for the diagnosis of SC compared with redness plus IBE and microvascular irregularities (72% vs 52%, P = 0.002; and 59% vs 92%, P < 0.001, respectively). The accuracy of redness plus IBE and irregularities for the diagnosis of SC was significantly greater than using redness alone (82% vs 62%, respectively, P < 0.001).

CONCLUSION: Redness, IBE, and microvascular irregularities appear to be closely related to SC lesions. Magnified NBI endoscopy may increase the diagnostic accuracy of CWL endoscopy for SC.

Swallowing Evaluation in Patients With Unilateral Vocal Fold Immobility

BACKGROUND

Unilateral vocal fold immobility is the neurological disorder most frequently seen in the larynx that may cause swallowing dysfunction. The objective of this investigation was to evaluate the oral and pharyngeal phases of swallowing in patients with unilateral vocal fold immobility.

METHODS

It was evaluated by videofluoroscopy of the swallowing of 14 patients with unilateral vocal fold immobility and 11 control subjects. The examination was performed with swallows of 5 mL and 10 mL of liquid and paste boluses. The oral transit, pharyngeal transit and clearance, the duration of upper esophageal sphincter (UES) transit, the duration of the hyoid movement, and the timing of the events were measured.

RESULTS

With swallows of 10 mL of liquid bolus (controls: 0.23 ± 0.04s, patients: 0.27 ± 0.05s, p = 0.03) and 5 mL of paste bolus (controls: 0.18 ± 0.04s, patients: 0.22 ± 0.04s, p = 0.01) there was a longer duration of UES transit in patients compared with controls. The UES opened earlier in the control subjects with the increase in bolus volume from 5 mL to 10 mL (p < 0.05), an effect that was not seen in patients with vocal fold immobility.

CONCLUSIONS

We conclude that patients with unilateral vocal fold immobility may have alteration of bolus transit through the UES and have no adaptation in the swallowing timing related to the increase in bolus volume.

PET/CT-MR Imaging in Head and Neck Cancer Including Pitfalls and Physiologic Variations

This article emphasizes the strengths and potential pitfalls of functional and anatomic imaging in patients who have head and neck cancer with an emphasis on the treated neck, including patients who have undergone surgery and/or radiation therapy. Anatomic and molecular imaging together allow optimal evaluation and interpretation of a patient who has cancer. Effective assessment of patients who have head and neck cancer can be achieved through a careful review of pertinent anatomy, with awareness of the physiologic variations (especially those in the treated head and neck) seen in PET imaging, and analysis of both the PET and cross-sectional images.

Spontaneous Pharyngeal Perforation After Forceful Vomiting: The Difference from Classic Boerhaave's Syndrome

Boerhaave's syndrome is spontaneous transmural perforation of the esophagus, which occurs most often after forceful vomiting or retching. This commonly occurs in the lower third of the esophagus but spontaneous perforation of the pharynx or cervical esophagus is extremely rare. This case presented a 20-yr-old healthy man with spontaneous pharyngeal perforation after forceful vomiting who had no history of instrumentation, cervical trauma, or having eaten anything sharp. Cervical pain and crepitus were the early symptom and sign of pharyngeal perforation and the rupture was detected on gastrografin swallow and CT examinations. The rupture site was higher than the upper esophageal sphincter, differing from Boerhaave's syndrome. The patient was conservatively managed without significant morbidity and mortality. Although this may resolve without surgical intervention, the pharyngeal rupture should receive early detection and clinical attention for preventing potential morbidity by late diagnosis.