This review assesses regenerative medicine of the upper aerodigestive tract during the first two decades of the twenty-first century, focusing on end-stage fibrosis and tissue loss in the upper airways, salivary system, oropharynx and tongue.

PubMed, Embase, Google Scholar, Cochrane Library, Medline and clinicaltrials.org were searched from 2000 to 2019. The keywords used were: bioengineering, regenerative medicine, tissue engineering, cell therapy, regenerative surgery, upper aerodigestive tract, pharynx, oropharynx, larynx, trachea, vocal cord, tongue and salivary glands. Original studies were subcategorised by anatomical region. Original human reports were further analysed. Articles on periodontology, ear, nose and maxillofacial disorders, and cancer immunotherapy were excluded.

Of 716 relevant publications, 471 were original studies. There were 18 human studies included, within which 8 reported airway replacements, 5 concerned vocal fold regeneration and 3 concerned salivary gland regeneration. Techniques included cell transplantation, injection of biofactors, bioscaffolding and bioengineered laryngeal structures.

Moderate experimental success was identified in the restoration of upper airway, vocal fold and salivary gland function. This review suggests that a shift in regenerative medicine research focus is required toward pathology with a higher disease burden.

Simulation training has become a key part of the surgical curriculum over recent years. Current trainees face significantly reduced operating time as a result of the coronavirus disease 2019 pandemic, alongside increased costs to surgical training, thus creating a need for low-cost simulation models.

A systematic review of the literature was performed using multiple databases. Each model included was assessed for the ease and expense of its construction, as well as its validity and educational value.

A total of 18 low-cost simulation models were identified, relating to otology, head and neck surgery, laryngeal surgery, rhinology, and tonsil surgery. In only four of these models (22.2 per cent) was an attempt made to demonstrate the educational impact of the model. Validation was rarely formally assessed.

More efforts are required to standardise validation methods and demonstrate the educational value of the available low-cost simulation models in otorhinolaryngology.

To compare the efficacy of bone pâté versus bioactive glass in mastoid obliteration.

This randomised parallel groups study was conducted at a tertiary care centre between September 2017 and August 2019. Sixty-eight patients, 33 males and 35 females, aged 12–56 years, randomly underwent single-stage canal wall down mastoidectomy with mastoid obliteration using either bone pâté (n = 35) or bioactive glass (n = 33), and were evaluated 12 months after the operation.

A dry epithelised cavity (Merchant's grade 0 or 1) was achieved in 65 patients (95.59 per cent). Three patients (4.41 per cent) showed recidivism. The mean air–bone gap decreased to 16.80 ± 4.23 dB from 35.10 ± 5.21 dB pre-operatively. The mean Glasgow Benefit Inventory score was 30.02 ± 8.23. There was no significant difference between the two groups in these outcomes. However, the duration of surgery was shorter in the bioactive glass group (156.87 ± 7.83 vs 162.28 ± 8.74 minutes; p = 0.01).

The efficacy of both materials was comparable.

To determine the effect of cochlear dimensions on cochlear implant selection in cochlear hypoplasia patients.

Temporal bone computed tomography images of 36 patients diagnosed with cochlear hypoplasia between 2010 and 2016 were retrospectively reviewed and compared with those of 40 controls without sensorineural hearing loss.

Basal turn length and mid-modiolar height were significantly lower in the cochlear hypoplasia patients with subtypes I, II and III than in the control group (p < 0.001). Mid-scalar length was significantly shorter in subtype I–III patients as compared with the control group (p < 0.001). In addition, cochlear canal length (measured along the lateral wall) was significantly shorter in subtype I–IV patients than in the control group (subtypes I–III, p < 0.001; subtype IV, p = 0.002)

Cochlear hypoplasia should be considered if basal turn length is less than 7.5 mm and mid-modiolar height is less than 3.42 mm. The cochlear implant should be selected according to cochlear hypoplasia subgroup. It is critically important to differentiate subtype II from incomplete partition type I and subtype III from a normal cochlea, to ensure the most appropriate implant electrode selection so as to optimise cochlear implantation outcomes.

The effects of iron deficiency on the prognosis of idiopathic sudden sensorineural hearing loss are unclear. This study aimed to investigate the association between serum iron levels and idiopathic sudden sensorineural hearing loss prognosis and its usefulness as an independent prognostic marker for idiopathic sudden sensorineural hearing loss.

The audiological and haematological data, including hearing recovery and serum iron levels, of 103 patients with idiopathic sudden sensorineural hearing loss evaluated between 2015 and 2018 were retrospectively analysed.

The overall complete recovery rate was 16.5 per cent. Initial higher hearing threshold was associated with poor idiopathic sudden sensorineural hearing loss prognosis. Serum iron levels were significantly higher in the complete recovery group than in the non-complete recovery group (p < 0.05).

The possibility of complete recovery from idiopathic sudden sensorineural hearing loss was significantly lower with lower serum iron levels, suggesting that the serum iron level might be a novel prognostic marker for idiopathic sudden sensorineural hearing loss.

To evaluate the spectral resolution achieved with a cochlear implant in users who were implanted using round window route electrode insertion versus a traditional cochleostomy technique.

Twenty-six patients were classified into two groups according to the surgical approach: one group (n = 13) underwent cochlear implantation via the round window technique and the other group (n = 13) underwent surgery via cochleostomy.

A statistically significant difference was found in spectral ripple discrimination scores between the round window and cochleostomy groups. The round window group performed almost two times better than the cochleostomy group. Differences between Turkish matrix sentence test scores were not statistically significant.

The spectral ripple discrimination scores of patients who had undergone round window cochlear implant electrode insertion were superior to those of patients whose cochlear implants were inserted using a classical cochleostomy technique.

This study developed an assessment tool that was based on the objective structured assessment for technical skills principles, to be used for evaluation of surgical skills in cortical mastoidectomy. The objective structured assessment of technical skill is a well-established tool for evaluation of surgical ability. This study also aimed to identify the best material and printing method to make a three-dimensional printed temporal bone model.

Twenty-four otolaryngologists in training were asked to perform a cortical mastoidectomy on a three-dimensional printed temporal bone (selective laser sintering resin). They were scored according to the objective structured assessment of technical skill in temporal bone dissection tool developed in this study and an already validated global rating scale.

Two external assessors scored the candidates, and it was concluded that the objective structured assessment of technical skill in temporal bone dissection tool demonstrated some main aspects of validity and reliability that can be used in training and performance evaluation of technical skills in mastoid surgery.

Apart from validating the new tool for temporal bone dissection training, the study showed that evolving three-dimensional printing technologies is of high value in simulation training with several advantages over traditional teaching methods.

To investigate the effects of nasal irrigation with sodium hyaluronate and surfactant solutions on mucociliary clearance time in patients with mild persistent allergic rhinitis.

A total of 120 patients diagnosed with mild persistent allergic rhinitis were enrolled in this prospective study. The patients were allocated randomly to the surfactant, sodium hyaluronate or isotonic saline (as a control) nasal irrigation group. The mucociliary clearance times and improvements in mucociliary clearance times were compared.

Improvements in mean mucociliary clearance time were significantly greater in the surfactant and sodium hyaluronate groups than in the control group (p < 0.01). The mean post-treatment mucociliary clearance time of the surfactant group was significantly lower than that of the control (p < 0.001) and sodium hyaluronate groups (p = 0.03).

Surfactant and sodium hyaluronate nasal irrigation solutions may both be used as adjunctive treatments for allergic rhinitis. Surfactant nasal irrigation resulted in better mucociliary clearance times.

Fear of contracting coronavirus disease 2019 may be the latest addition to the barriers to clinic attendance. This study aimed to examine the impact of coronavirus disease 2019 and other variables on non-attendance rate at an out-patient clinic.

Clinic attendance at the Department of Otolaryngology and Head and Neck Surgery, Waikato Hospital, New Zealand, was assessed. For each appointment, the impact of coronavirus disease 2019 and other variables on non-attendance rate were analysed.

In total, 1963 appointments were scheduled, with 194 non-attendances (9.9 per cent). Patients who had their appointments confirmed beforehand were 10.0 times more likely to attend their appointment. Sex, socioeconomic status, ethnicity and age were found to impact non-attendance rate.

In New Zealand, coronavirus disease 2019 does not appear to be a barrier to out-patient clinic appointment attendance. The patient's age, sex, ethnicity, socioeconomic status and prior appointment confirmation were found to influence clinic attendance.

Tonsillectomy is a painful surgery performed in cases of recurrent tonsillitis. Application of platelet-rich plasma to diminish the pain and morbidity post-tonsillectomy is gaining importance. This study evaluated post-operative pain and morbidity after autologous platelet-rich plasma application on the tonsil beds during tonsillectomy.

Participants were randomised into group 1 (n = 28, peri-operative platelet-rich plasma intervention) and group 2 (n = 28, control). Post-tonsillectomy, patients were assessed (day 0, 1, 2, 3, 7 and 14) for pain, healing and time taken to return to normal activity. Data were analysed by independent t-test and chi-square test with p ≤ 0.05 as the significance level.

A significant decrease in the mean pain score up to day 7 (p < 0.05) and tonsillar fossae healing on days 2 and 3 (p < 0.05) post-tonsillectomy was noted. The majority of the patients returned to their routine activities after a week post-tonsillectomy.

Platelet-rich plasma application was effective in accentuating healing and reducing post-tonsillectomy pain and morbidity.

This technical note describes a novel method of cauterising the posterior nasal cavity through the use of a plastic straw and silver nitrate.

This technique aims to prevent unwanted damage to surrounding nasal mucosa.

Once the nasal cavity has been prepared for cauterisation, the silver nitrate stick is navigated to the bleeding point covered by the plastic straw. The silver nitrate stick is then advanced onto the bleeding point allowing precise cauterisation of the nasal mucosa, without effecting surrounding healthy mucosa.

This paper describes a simple method of securing tissue coverage of the great vessels at the initial surgery by rotating the divided sternal heads of the sternocleidomastoid muscle, a routine step during laryngectomy, and approximating them to the prevertebral fascia. The paper presents an illustrated case example where this technique in a salvage laryngectomy repair resulted in a protected vascular axis following a salivary leak.

Since utilising this technique, there has been a marked reduction in the requirement of subsequent flap procedures to protect vessels, and no episodes of threatened or actual carotid blowout.

Dural venous sinus injury is a rare complication of otological surgery that can lead to life-threatening sequelae, the management of which is complex and poorly described.

This paper describes the case of a 40-year-old female who underwent routine right myringoplasty complicated by sigmoid sinus laceration. The patient subsequently developed right-sided lateral sinus thrombosis leading to fulminant intracranial hypertension. The patient underwent successful emergency management by surgical reconstruction of the sigmoid sinus, followed by endovascular thrombolysis, catheter balloon angioplasty and endovascular stenting.

Torrential haemorrhage following otological procedures is uncommon and rarely requires packing of a bleeding venous sinus. This case highlights that injury to a highly dominant venous sinus can lead to venous outflow obstruction and life-threatening intracranial hypertension. To our knowledge, the development of this complication following otological surgery and its management has not been reported previously.

For recalcitrant chronic maxillary sinusitis, modified endoscopic medial maxillectomy has been shown to be clinically beneficial after failed maxillary antrostomy as endoscopic medial maxillectomy may offer improved topical therapy delivery. This study compared irrigation patterns after maxillary antrostomy versus endoscopic medial maxillectomy, using computational fluid dynamic modelling.

A 54-year-old female with left chronic maxillary sinusitis underwent maxillary antrostomy, followed by endoscopic medial maxillectomy. Computational fluid dynamic models were created after each surgery and used to simulate irrigations.

After maxillary antrostomy, irrigation penetrated the maxillary sinus at 0.5 seconds, initially contacting the posterior wall. The maxillary sinus was half-filled at 2 seconds, and completely filled at 4 seconds. After endoscopic medial maxillectomy, irrigation penetrated the maxillary sinus at 0.5 seconds and immediately contacted all maxillary sinus walls. The maxillary sinus was completely filled by 2 seconds.

Computational fluid dynamic modelling demonstrated that endoscopic medial maxillectomy allowed faster, more forceful irrigation to all maxillary sinus walls compared with maxillary antrostomy.