Minor Parotidectomy Complications: A Systematic Review

A Safety and Feasibility Trial of Ultrasound-Guided Radiofrequency Ablation of Parotid Warthin's Tumor

OBJECTIVE

To determine if ultrasound-guided (USG) radiofrequency ablation (RFA) of Parotid Warthin's tumor under local anesthesia is a safe and effective procedure.

STUDY DESIGN

Safety and feasibility study.

SETTING

Tertiary academic medical center.

METHODS

This is an IDEAL phase 2a trial in a tertiary referral center. Twenty patients with Parotid Warthin's tumor were recruited. RFA was done between September and December 2021 for all 20 patients using a CoATherm AK-F200 machine with a disposable, 18G × 7 mm radiofrequency electrode. Results and follow-up statistics were compared with a historic sample of patients with parotid Warthin's tumor who underwent parotidectomy between 2019 and 2021 in the same center.

RESULTS

Nineteen patients were included in the analysis as 1 patient dropped out after 4 weeks of follow-up. The mean age for the RFA group was 67 years old with most of them being male smokers. At a median of 45 weeks (44-47 weeks) postprocedure there was a 7.48 mL (68.4%) volume reduction compared to baseline. Three patients had transient facial nerve (FN) paresis, 1 recovered within hours, and the other 2 by 12 weeks follow-up. Three patients had great auricular nerve numbness; 1 patient had infected hematoma treated in an out-patient manner. Compared to a historic cohort of parotidectomy patients for Warthin's tumor, there was no significant difference in FN paresis and other minor complications between the 2 treatment modalities.

CONCLUSION

The current analysis suggests that USG RFA of Warthin's Tumor is a safe alternative to parotidectomy with shorter operative time and length of stay.

Management of a salivary fistula following removal of mandibular distractors in a neonate

There are multiple management options for treatment of iatrogenic salivary fistulas including reduced oral intake, pressure dressings, total parotidectomy, tympanic neurectomy, surgical repair, radiation therapy, and pharmacotherapy. However, the optimal management of salivary fistulas is unclear due to uncertain efficacy and adverse outcomes. We present a case of a neonate that developed a submandibular fistula following removal of mandibular distractors and was ultimately successfully managed using intralesional botulinum toxin injection. The purpose of this communication is to summarize the management of this complication in the context of the current literature.

Outpatient parotidectomy with or without the use of a post-operative drain: A retrospective bi-institutional study

OBJECTIVE

Parotid surgery is historically performed as an inpatient procedure and suctions drains are predominantly used during surgery. Recent literature provides evidence that outpatient parotid surgery is safe and effective. Our study aims to describe the results of drainless outpatient parotidectomy and outpatient parotidectomy with drain placement and compare their outcomes.

DESIGN

Retrospective cohort study.

SETTING

Bi-institutional retrospective cohort study.

PARTICIPANTS

Patients that underwent outpatient drain-less parotidectomy and patients that underwent outpatient parotidectomy with post-operative drain placement.

MAIN OUTCOME MEASURES

Complication rates, unplanned post-operative visits, unplanned prolonged stay.

RESULTS

Three hundred eighty patients underwent outpatient parotidectomy with drain placement and 31 patients underwent outpatient drainless parotidectomy in two different hospitals. The incidence of haematoma (drain: 3.1% vs. drainless: 0%, p = 1), infection (drain: 14.3% vs. drainless: 13.8%, p = 1) and salivary fistula (drain: 5.6% vs. drainless: 3.4, p = 1) were comparable between both groups. Seroma or sialocele was more frequently seen in the drain-less group (27.6% vs. 6.2%, p < .001), but were all managed conservatively. Within 10 days after surgery, unplanned visits seemed more frequent in the drain group, although the difference was not statistically significant (14.9% vs. 3.4%, p = .16).

CONCLUSIONS

Outpatient parotid surgery with or without the use of a post-operative drain is safe, practical and feasible. Same-day discharge with and without drain placement yield comparable outcomes. However, the results need to be interpreted cautiously as this study was limited by a small cohort of parotidectomies without drain placement. Future studies should further compare both approaches.

Tratamiento quirúrgico de la patología tumoral de la glándula parótida. Estudio descriptivo de 263 parotidectomías

Introducción y objetivo: Los tumores salivales representan el 3-10% de los tumores de cabeza y cuello, siendo el 75-80% de origen parotídeo y en su mayoría benignos. La parotidectomía es una técnica quirúrgica que consiste en la exéresis de la glándula parótida. Existen diversos tipos; parotidectomía superficial (PS), parotidectomía superficial parcial (PSP) y parotidectomía total (PT). En esta última, al no respetarse el nervio facial (NF), las complicaciones son más frecuentes. Nuestro objetivo es analizar el resultado (tasa de recidiva y complicaciones) de la parotidectomía como técnica quirúrgica empleada en el manejo de la patología parotídea, así como evaluar qué prueba complementaria es la más eficaz en el diagnostico prequirúrgico de la patología parotídea tumoral. Material y método: Se realiza un estudio retrospectivo incluyendo 263 pacientes tratados mediante PS o PT entre enero de 2004 y diciembre de 2020 en el Hospital Universitario de Fuenlabrada. Se registraron datos demográficos, tiempo de evolución de la lesión, pruebas complementarias, protocolo quirúrgico y complicaciones postoperatorias. Se analiza principalmente la correlación positiva entre las pruebas realizadas prequirúrgicas (PAAF, ecografía, TC y RMN), con el diagnóstico definitivo anatomopatológico obtenido tras examinar la pieza quirúrgica. También se describe la tasa de paresia y parálisis facial y otras complicaciones habidas. Resultados: Se incluyeron 263 pacientes tratados mediante parotidectomía. El tiempo de evolución medio de las lesiones parotídeas fue de 15 meses (DE 19.88). La sensibilidad de la PAAF en nuestro estudio fue de 68.7%. Se realizó ecografía en un 44.10% de los pacientes, TC en un 77.94% y RMN en un 15.20%, mostrando una sensibilidad de 18.05%, 31.21% y 45%, respectivamente. La cirugía más frecuente fue la PS (43.3%, 114/263), seguida por la PSP (41.1%, 108/263) y, por último, la menos habitual fue la PT (15.58%, 41/263). Los tumores benignos fueron más frecuentes (84.79%, 223/263), siendo el adenoma pleomorfo el más frecuente, 45.73% (102/223). Dentro del grupo de tumores malignos (15.20%, 40/263), el más habitual fue el carcinoma mucoepidermoide (17.5%, 7/40) y las metástasis (17.5%, 7/40). La paresia facial, según la escala de House-Brackmann, fue leve (grado I y II) y transitoria en la mayoría de los casos, apareciendo en un 31.55%. Tras un periodo medio de seguimiento de 6 años no se han encontrado recidivas post parotidectomía por ningún tipo tumoral en nuestro estudio. Conclusión: En nuestra muestra, los tumores benignos representaron la gran mayoría de la patología parotídea. Dentro de este grupo, el adenoma pleomorfo fue el más frecuente. La PAAF fue la prueba complementaria con mejor correlación con el diagnostico anatomopatológico definitivo, seguida por la RMN. La paresia facial leve (grados I y II) y transitoria fue la complicación postquirúrgica mas habitual.

Electrocautery, Harmonic, and Thunderbeat Instruments in Parotid Surgery: A Retrospective Comparative Study

The aim of this retrospective study has been to compare the surgical outcomes of patients undergoing superficial parotidectomy with three different instruments: bipolar electrocautery, ultrasound, and mixed energy instruments. The clinical records of 102 patients who had undergone superficial parotidectomy for benign tumors between January 2016 and April 2022 were considered. Based on the tool used during the surgery, the patients were divided into three study groups: classic electrocautery hemostasis group (CH group), ultrasonic instrument group (HA group), and combined energy instrument group (TB group). The duration of surgery, the total post-operative drainage volume, and the intra-operative blood loss were significantly higher in the CH group compared to the HA and the TB group, while the differences were not significant between the latter two groups. Facial nerve weakness was detected in 45.9% of the CH group, 12.5% of the HA group, and 21.2% of the TB group. The rate of facial nerve dysfunction in the CH group was significantly higher than in the HA group (0.011). In the patients who experienced post-operative facial nerve dysfunction, the recovery time was significantly shorter in the HA group compared to the CH and the TB group. The HA and TB groups have demonstrated comparable and significantly better surgical outcomes than bipolar electrocautery. Ultrasound instruments have been shown to cause, in comparison with the other techniques, a lower rate of temporary facial nerve dysfunction and, if this is present, lead to a faster spontaneous recovery time.

Postauricular Incision Versus Modified Blair Incision in Parotidectomy: A Systematic Review and Meta-Analysis

OBJECTIVE

The mainstay of first-line treatment of parotid tumors is adequate surgical removal. The present study was conducted to compare the differences between parotidectomy with postauricular incision (PI) and modified Blair incision (MBI).

DATA SOURCES

A systematic search of PubMed, Embase and the Cochrane Library was performed.

METHODS

The data of interest and study characteristics were extracted from the included studies. Statistical analysis was performed with Comprehensive Meta-Analysis software (version 3; BioStat, Englewood, NJ). Dichotomous data and continuous data were analyzed by calculating the risk difference and the mean difference with the 95% confidence interval respectively.

RESULTS

Four retrospective studies were included in the present meta-analysis. The pooled results revealed that the cosmetic satisfaction score was higher in the PI group (MD = 2.67; 95% CI, 2.12 to 3.23) and that intraoperative blood loss was lower in the PI group (MD =  -55.35; 95% CI, -100.33 to -10.36). The operative duration (MD  =  -5.15; 95% CI, -24.06 to 13.75), tumor size (MD  =  -.07; 95% CI, -.27 to .13) and incidences of common postoperative complications were comparable between the two groups.

CONCLUSIONS

According to these findings, the use of PI in parotidectomies may be one of the options for improving cosmetic outcomes. This technique may be considered if oncological safety can be secured.

Comparison of various surgical incisions in parotidectomy: A systematic review and network meta-analysis

Background

This network meta-analysis aimed to comprehensively compare the operative and postoperative outcomes of different parotidectomy incisions.

Methods

Embase, PubMed, Web of Science, and Cochrane Central Register of Controlled Trials were searched up to April 2022. A complete Bayesian network meta-analysis was performed using the Markov Monte Carlo method in OpenBUGS.

Results

Seventeen studies with 1609 patients were included. Thirteen were retrospective cohort studies, three were prospective cohort studies, and one was a randomized controlled study. The quality of evidence was rated as very low in most comparisons. The incision satisfaction score of the modified facelift incision (MFI), retroauricular hairline incision (RAHI), V-shaped incision (VI) were higher than that of the modified Blair incision (MBI) (MBI vs. MFI: mean difference [MD] -1.39; 95% credible interval [CrI] -2.23, -0.57) (MBI vs. RAHI: MD -2.25; 95% CrI -3.40, -1.12) (MBI vs. VI: MD -2.58; 95% CrI -3.71, -1.46); the tumor size treated by VI was smaller than that by MBI (MD 5.15; 95% CrI 0.76, 9.38) and MFI (MD 5.16; 95% CrI 0.34, 9.86); and the risk of transient facial palsy in the MFI was lower than that in the MBI (OR 2.13; 95% CrI 1.28, 3.64). There were no differences in operation time, drainage volume, wound infection, hematoma, salivary complications, Frey syndrome, or permanent facial palsy between incision types.

Conclusion

The traditional MBI is frequently used for large tumor volumes, but the incision satisfaction score is low and postoperative complication control is poor. However, emerging incisions performed well in terms of incision satisfaction scores and control of complications. More randomized controlled trials are needed to compare the different parotidectomy incisions. Patients should be fully informed about the characteristics of each incision to make the most informed decision, along with the physician’s advice.

Systematic Review Registration

PROSPERO, identifier CRD42022331756

Extracapsular dissection by the sternocleidomastoid muscle-parotid space approach reduces the risks of postparotidectomy sialocele and salivary fistula

BACKGROUND

Postoperative sialoceles and fistulas are frequent surgical complications of parotid tumor resection. Extracapsular dissection by the sternocleidomastoid muscle-parotid space approach (ECD-SMPSA) is a minimally invasive technique. To our knowledge, the characteristics of sialoceles and fistulas secondary to ECD-SMPSA have not been reported.

METHODS

This prospective study enrolled 52 patients who underwent ECD-SMPSA without sialocele/fistula prevention measures. Postoperative sialoceles and fistulas were evaluated during 2 months of follow-up.

RESULTS

Among the 52 patients, only one male patient developed a mild sialocele. No salivary fistulas occurred. The overall rate of sialocele/fistula formation was 1.92%.

CONCLUSIONS

When treating clinically benign tumors that involve the sternocleidomastoid muscle-parotid space, ECD-SMPSA may prevent postoperative formation of sialoceles and salivary fistulas.

Repair of a postaural fistula with a suprafascial radial forearm free flap

We describe the case of a patient with the rare complication of a chronic postaural fistula following repeated and extensive surgery and adjuvant radiotherapy to the head and neck for a pleomorphic adenoma of the parotid gland. This case demonstrates the importance and value of thorough preoperative planning for major head and neck reconstruction, particularly if the area for reconstruction has distorted anatomy due to prior treatment or damage. In complex free flap reconstruction, it is important to investigate the recipient site with the help of arteriography and give due consideration to the donor site and its postoperative management. We highlight the importance of multidisciplinary work for the care of these patients not only intraoperatively, but also in the preoperative planning stage, and perhaps most importantly in the postoperative care.

Impact of great auricular nerve sacrifice on sensory disturbance after parotidectomy

PURPOSE

To investigate the association between great auricular nerve (GAN) sacrifice during parotidectomy and postoperative sensory disturbance.

MATERIALS AND METHODS

Patients who underwent parotidectomy between November 2016 and May 2020 at a single academic institution were included in this retrospective chart review. Operative notes were reviewed to determine incidence of GAN sacrifice. Prevalence of patient-reported sensory complaints in the GAN distribution and time to spontaneous resolution of symptoms were assessed.

RESULTS

Of 305 parotidectomy patients, 111 (36.4%) endorsed complaints of postoperative sensory disturbances in the GAN distribution typically characterized by numbness or shooting pains. GAN sacrifice was present in 9 (8.1%) of 111 patients who experienced sensory disturbances compared to 9 (4.6%) who reported no sensory disturbances (p > 0.05). Twenty-five patients (32.5%) experienced spontaneous resolution of symptoms at their most recent follow-up at a mean of 6.2 months after onset of symptoms. Of those that experienced a sensory disturbance, GAN preservation was not significantly associated with likelihood of spontaneous recovery (p > 0.05).

CONCLUSIONS

We report the largest series to date of post-operative sensory disturbance in parotidectomy patients as it relates to intraoperative GAN sacrifice. Although the relationship between GAN sacrifice and the incidence of postoperative sensory disturbance and its subsequent resolution were not significant, we continue to advocate for GAN preservation to reduce incidence of postoperative sensory disturbances.

[Complications in the surgery of the parotid salivary glands. Causes, mechanisms of development, methods of prevention]

Operations for neoplasms of the parotid salivary gland require from the surgeon a deep knowledge of the anatomical and topographic features of this area and technical skill, which puts it in a number of «jewelry» operations that require patience and concentration. The review is devoted to the topic of specific postoperative complications after parotidectomy or subtotal resection of the gland. These include relapses of tumors, paralysis or paresis of facial muscles, Frey syndrome, salivary fistulas or sialocele, violation of skin sensitivity, soft tissue deformity. The review presents the frequency and causes of complications, mechanisms of their development, methods of prevention and elimination.

Systematic review and meta-analysis of modified facelift incision versus modified Blair incision in parotidectomy

Surgical removal is the treatment of choice for many neoplasms of the parotid gland. This meta-analysis aimed to evaluate the differences between parotidectomy using a modified facelift incision (MFI) and parotidectomy using a modified Blair incision (MBI). A systematic search of the available literature in PubMed, Embase and the Cochrane Library was performed. Studies of adult patients who underwent open parotidectomy with presumed benign parotid neoplasms based on preoperative examinations were reviewed. The surgical outcomes of the MFI and MBI groups were collected. Intraoperative and postoperative parameters, including operative time, tumor size, cosmetic satisfaction, and incidences of facial palsy, Frey's syndrome and salivary complications, were compared. Dichotomous data and continuous data were analyzed by calculating the risk difference (RD) and the mean difference (MD) with the 95% confidence interval (CI), respectively. Seven studies were included in the final analysis. The pooled analysis demonstrated that the cosmetic satisfaction score was significantly higher in the MFI group (MD = 1.66; 95% CI 0.87-2.46). The operative duration in the MFI group was significantly longer than that in the MBI group (MD = 0.07; 95% CI 0.00-0.14). The MFI group exhibited a smaller tumor size (MD = - 2.27; 95% CI - 4.25 to - 0.30) and a lower incidence of Frey's syndrome (RD = - 0.18; 95% CI - 0.27 to - 0.10). The incidence of postoperative temporary facial palsy (RD = - 0.05; 95% CI - 0.12 to 0.03), permanent facial palsy (RD = - 0.01; 95% CI - 0.06 to 0.03) and salivary complications (RD = - 0.00; 95% CI - 0.05 to 0.05) was comparable between the two groups. Based on these results, MFI may be a feasible technique for improving the cosmetic results of patients who need parotidectomy when oncological safety can be ensured.

Predictors of Sialocele or Salivary Fistula After Partial Superficial Parotidectomy for Benign Parotid Tumor: A Retrospective Study

PURPOSE

Partial superficial parotid (PSP) resection is the mainstay of treatment for benign parotid tumor. Unfortunately, the post-surgical formation of sialocele or salivary fistula is a well-recognized complication of parotid surgery. The aim of this study was to determine the predictors of sialocele or salivary fistula after PSP resection for parotid benign tumor.

METHODS

This retrospective cohort study includes patients who underwent PSP resection for benign parotid tumors from January 1, 2015 to December 31, 2019. The predictor variables were demographic data, systemic disease, smoking history, tumor size and type, surgical approach, and area. The outcome variables were the occurrence of sialocele or salivary fistula after PSP resection. Each possible risk factor was then examined using univariate analysis. Variables associated with sialocele or salivary fistula in the univariate analysis were then included in a multiple logistic regression model, and analyzed for possible factors related to the occurrence of sialocele or salivary fistula after partial superficial parotid resection.

RESULTS

The sample was composed of 872 subjects with a mean age of 51.0 ± 8.3, and 59.5% were male. The frequency of sialocele or salivary fistula after partial superficial parotid resection was 10.4% (n = 92). Based on the multiple logistic regression model, hypertension and location of the lesion were associated with sialocoele formation. Hypertension was associated with a decreased risk for the formation of sialocele or salivary fistula (ORs = 0.6, 95% CI = [0.4,1.003], P = .051). When compared the superior lesions, anterior lesions were associated with a decreased risk for the formation of sialocele or salivary fistula (ORs = 0.32, 95% CI = [0.111,0.92], P = .034) and lesions in the middle were associated with an increased risk for sialocele or salivary fistula development (ORs = 2.315,95% CI = [1.199,4.469], P = .012).

CONCLUSIONS

The incidence of sialocele or salivary fistula development was 10.4% in patients undergoing partial superficial parotidectomy in this study. Moreover, middle and anterior tumor location was shown to increase sialocele or salivary fistula risk.

Surgical interventions for management of benign parotid tumors: A systematic review and network meta-analysis

The impact of the extent of parotid surgery on postoperative complications has long been considered a topic of controversy. The aim of the current network meta-analysis (NMA) is to answer the following questions: (1) Does the extent of surgical resection of benign parotid tumors increase the risk of postoperative complications? (2) What is the best surgical intervention for treatment of benign parotid tumors that can provide an acceptable balance between tumor recurrence rate and other postoperative complications? A comprehensive search on PubMed, Embase, Scopus, and Cochrane library was conducted to identify the eligible studies. The outcome was the incidence of tumor recurrence, facial nerve weakness (temporary [TFW] or permanent [PFP]), Frey's syndrome (FS), sialocele, and salivary fistula. The Bayesian network meta-analysis (NMA) accompanied by a random effect model and 95% credible intervals (CrI) were calculated using the GeMTC R package. Forty-four studies with a total of 7841 participants were included in the current NMA comparing five surgical interventions, namely enucleation, extracapsular dissection (ECD), partial superficial parotidectomy (PSP), superficial parotidectomy (SP), and total parotidectomy (TP). Enucleation showed the highest recurrence rate compared to ECD, SPS, SP, and TP. No statistical differences were observed concerning the recurrence rate when ECD, PSP, SP, and TP were compared together. There was an increased incidence of TFW and FS with the increase in the extent of parotid resection, while no significant difference was found when comparing enucleation with ECD and PSP. SP showed the highest incidence of PFP, and salivary fistula compared to ECD, PSP, and TP. The tumor recurrence rates in enucleation, ECD, PSP, SP, and TP were 14.3%, 3.6%, 3.7%, 2.8%, and 1.4%, respectively. The current NMA demonstrated that the risk of TFW and FS increases with the increase in the extent of parotid resection and that ECD and PSP can be considered the treatment of choice for benign parotid tumors, as both provide an acceptable balance between the incidence of tumor recurrence and facial nerve dysfunction.

Tissue sealant versus surgical drain following parotidectomy

PURPOSE

Sialocele and salivary fistula are recognised complications of parotid surgery and have been reported to be more common with less extensive parotidectomy. We investigated the efficacy of tissue sealant(Cunniffe et al., 2019) ¹ as an alternative to surgical drainage in terms of length of hospital stay (LOS), cost, and incidence of wound complications.

METHODS

The study comprised a retrospective review of a prospectively maintained parotidectomy database at a single tertiary Head and Neck referral centre between 2009 and 2020. Cases undergoing concomitant neck dissection or major skin resection were excluded. Patients were divided into Group 1 (without tissue sealant), and Group 2 (with tissue sealant). Patients were also divided based on extent of surgery 1) Extracapsular dissection/Partial superficial parotidectomy 2) Superficial/total parotidectomy.

RESULTS

Of 202 included patients, there were 146 in Group 1 (143 with drain), and 56 in Group 2 (7 with drain). Compared to Group 1, Group 2 had a significantly shorter LOS (mean 1.4 ± 0.98 versus 3.1 ± 1.29 days, p < 0.05) and estimated cost (€1386 versus €2736). There was no significant difference in the complication rates (15.8% Group 1 versus 10.7% Group 2, p = 0.50). Group 1 showed a higher incidence of complications in patients undergoing less extensive parotidectomy (19/70 versus 4/76, p = 0.02), whereas in Group 2, the difference was not significant (5/30 versus 1/26, p = 0.20).

CONCLUSION

The use of tissue sealant as an alternative to surgical drains after parotidectomy facilitates reduced LOS and cost savings without increase in morbidity.

LEVEL OF EVIDENCE

3.

Outpatient Parotidectomy, a Safety and Financial Review

OBJECTIVE

The objective of this study is to investigate the safety, efficacy, and potential cost-savings of the outpatient parotidectomy procedure.

METHODS

This is a retrospective chart review of all patients who underwent a parotidectomy at a large academic center from 2015 through 2019 including demographic data, postoperative complications, drain placement, readmission, and financial cost. A comparison was performed between patients who underwent an outpatient vs inpatient parotidectomy.

RESULTS

A total of 335 patients underwent parotidectomy (136 outpatient; 199 inpatient). Comparison of patient demographics, common comorbidities, tumor size, tumor type, postoperative complications, and readmission rate was similar between the inpatient and outpatient cohorts. The overall mean cost difference between inpatient parotidectomy and outpatient parotidectomy for all years was $1528.58 (95%CI: $1139-$1916).

CONCLUSION

The outpatient parotidectomy procedure has a comparable safety profile to the inpatient procedure while providing a significant cost-savings benefit.

Building a Functional Salivary Gland for Cell-Based Therapy: More than Secretory Epithelial Acini

A few treatment options exist for patients experiencing xerostomia due to hyposalivation that occurs as a result of disease or injury to the gland. An opportunity for a permanent solution lies in the field of salivary gland replacement through tissue engineering. Recent success emboldens in the vision of producing a tissue-engineered salivary gland composed of differentiated salivary epithelial cells that are able to differentiate to form functional units that produce and deliver saliva to the oral cavity. This vision is augmented by advances in understanding cellular mechanisms that guide branching morphogenesis and salivary epithelial cell polarization in both acinar and ductal structures. Growth factors and other guidance cues introduced into engineered constructs help to develop a more complex glandular structure that seeks to mimic native salivary gland tissue. This review describes the separate epithelial phenotypes that make up the gland, and it describes their relationship with the other cell types such as nerve and vasculature that surround them. The review is organized around the links between the native components that form and contribute to various aspects of salivary gland development, structure, and function and how this information can drive the design of functional tissue-engineered constructs. In addition, we discuss the attributes of various biomaterials commonly used to drive function and form in engineered constructs. The review also contains a current description of the state-of-the-art of the field, including successes and challenges in creating materials for preclinical testing in animal models. The ability to integrate biomolecular cues in combination with a range of materials opens the door to the design of increasingly complex salivary gland structures that, once accomplished, can lead to breakthroughs in other fields of tissue engineering of epithelial-based exocrine glands or oral tissues.