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Objective: Rhinosinusitis is one of the most common reasons for a visit to otolaryngology clinics. Some patients are candidates for sinus surgery. Infiltration of 1:100 000 adrenaline in the pterygopalatine fossa was studied, with the aim of evaluating the effect on bleeding in the surgical field., Methods: This double-blind clinical trial was conducted in 2021-2022 on 40 candidates for endoscopic sinus surgery. For each patient, one side of the pterygopalatine fossa was randomly selected to be infiltrated with a vasoconstrictor. Surgical field bleeding on each side was evaluated., Results: Blood loss was 35.8 ± 20.9 ml in the study group and 38.4 ± 23.7 ml for the control group, with no statistically significant difference between groups ( p = 0.49). In addition, there was no difference between the two groups in terms of the surgical field based on Boezaart scores., Conclusion: Although there are some recommendations on the usage of vasoconstrictors via the pterygopalatine foramen, debate remains.

Purpose: To develop and evaluate a transorbital endoscopic approach to the foramen rotundum to excise the maxillary nerve and infraorbital nerve branch., Methods: Cadaveric dissection study of 10 cadaver heads (20 orbits). This technique is predicated upon 1) an inferior orbital fissure release to facilitate access to the orbital apex and 2) the removal of the posterior maxillary wall to enter the pterygopalatine fossa (PPF). Angulations along the infraorbital nerve were quantified as follows: the first angulation was measured between the orbitomaxillary segment within the orbital floor and the pterygopalatine segment suspended within the PPF, while the second angulation was taken between the pterygopalatine segment and maxillary nerve as it exited the foramen rotundum. With refinement of the technique, the minimum amount of posterior maxillary wall removal was quantified in the final 5 cadaver heads (10 orbits)., Results: The mean distance from the inferior orbital rim to the foramen rotundum was 45.55 ± 3.24 mm. The first angulation of the infraorbital nerve was 133.10 ± 16.28 degrees, and the second angulation was 124.95 ± 18.01 degrees. The minimum posterior maxillary wall removal to reach the PPF was 11.10 ± 2.56 mm (vertical) and 11.10 ± 2.08 mm (horizontal)., Conclusions: The transorbital endoscopic approach to an en bloc resection of the infraorbital nerve branch up to its maxillary nerve origin provides a pathway to the PPF. This is relevant for nerve stripping in the context of perineural spread. Other applications include access to the superior portion of the PPF in selective biopsy cases or in concurrent orbital pathology., Competing Interests: The authors have no financial or conflicts of interest to disclose., (Copyright © 2024 The American Society of Ophthalmic Plastic and Reconstructive Surgery, Inc.)

Purpose: The purpose of this article and accompanying video is to demonstrate a transorbital endoscopic approach for accessing the pterygopalatine fossa (PPF). This technique does not require a skin incision, avoids dissection of critical neurovascular structures, and utilizes a comparatively small osteotomy. The 2 cases presented in this article highlight the utility of a transorbital endoscopic approach for accessing an anatomic region that has traditionally required more invasive techniques to reach., Methods: Description of surgical technique with 2 illustrative clinical cases and accompanying surgical video., Results: Surgical technique: A trans-conjunctival approach is taken to the inferior orbital rim, and a subperiosteal dissection is propagated posteriorly. The bone of the posterior orbital floor is then deroofed, and the superior portion of the posterior wall of the maxillary sinus is removed, allowing access to the PPF for an incisional biopsy., Case: A 76-year-old male with a history of left cheek squamous cell carcinoma presented with progressive V2 paresthesia and an abnormally enhancing lesion in the left PPF on MRI., Case: A 58-year-old male with no significant medical history presented with left facial numbness (V1-V3), ptosis, an abduction deficit, and decreased hearing. Contrast-enhanced MRI demonstrated an abnormally enhanced lesion in the left PPF extending to Meckel's cave.The transorbital approach described was used to successfully obtain a diagnostic biopsy in both cases., Conclusions: These cases highlight the utility of a transorbital endoscopic approach to the PPF as a less morbid alternative to traditional access. Patient selection is key to identifying appropriate cases., Competing Interests: The authors have no financial or conflicts of interest to disclose., (Copyright © 2023 The American Society of Ophthalmic Plastic and Reconstructive Surgery, Inc.)

Intraosseous dural arteriovenous fistulas (DAVFs) are distinct in that the fistula is located within the bone rather than the dura through which the dural vessels pass. It has been stated that only fistulas within marrow should be considered as intraosseous DAVFs rather than DAVFs with traditional angioarchitecture that erode into bone or are located within a bony foramen. The ambiguity in the definition may have contributed to the oversight and scarcity of relevant cases reported in the literature. Three- or four-dimensional digital subtraction angiography is useful for determining the location of the fistula and developing treatment plans. We present an intraosseous DAVF around the pterygopalatine fossa using a transvenous approach., (Copyright © 2023 Elsevier Inc. All rights reserved.)

The pterygopalatine fossa is a clinically inaccessible space deep in the face, and reports of pterygopalatine fossa abscesses are rare. The authors present the case of a 63-year-old woman presenting with a severe headache owing to an abscess involving the pterygopalatine fossa. On a computed tomography scan, inflammation of the right pterygopalatine fossa associated with right maxillary sinusitis and periapical inflammation and a cystic lesion around the tooth were observed. After administering appropriate antibiotics, the headache improved considerably, and endoscopic nasal surgery resulted in adequate abscess drainage. To the authors' knowledge, this case study is one of the few reporting the successful treatment of an abscess in the pterygopalatine fossa through an endoscopic transnasal approach., Competing Interests: The authors report no conflicts of interest., (Copyright © 2023 by Mutaz B. Habal, MD.)

Background: For aggressive maxillary sinus and pterygopalatine fossa (PPF) tumors, an en-bloc pterygomaxillectomy may be indicated., Methods: Five head specimens were used to study the feasibility of an en-bloc pterygomaxillectomy. Eighty-five non-pathological CT scans were used to compare the superior edge of the inferior turbinate (IT) and the middle turbinate tail (MT) as landmarks for the pterygoid osteotomy., Results: Through a combined sublabial-subperiosteal incision and transoral route, a mid-sagittal osteotomy through the hard palate and an axial osteotomy below the infraorbital foramen were performed. For the endoscopic pterygoid osteotomy, an infra-vidian transpterygoid approach was performed, subsequently removing the pterygomaxillectomy en-bloc. As landmarks, the osteotomies at the level of the MT tail and IT resected the pterygoid plates completely, but the IT osteotomy was further away from the vidian canal (7.5 vs. 6 mm)., Conclusions: The endoscopic-assisted en-bloc pterygomaxillectomy is feasible. The IT landmark is safe and ensures complete resection of the pterygoid plates., (© 2023 Wiley Periodicals LLC.)

Competing Interests: None

Pterygopalatine schwannomas are rare tumors which usually cause the symptoms of the traffic area by the tumors in the pterygopalatine fossa which is difficult to resection. This paper presents 1 rare case of pterygopalatine fossa tumor with hearing loss as the main complaint treated by total resection through the endoscopic endonasal approach., Competing Interests: The authors report no conflicts of interest., (Copyright © 2023 by Mutaz B. Habal, MD.)

Background: Both the endoscopic transnasal Denker's and prelacrimal approaches provide surgical access to the pterygopalatine fossa (PPF) and infratemporal fossa (ITF)., Objectives: This study compares the potential maximum exposure of the PPF and ITF and quantifies the difference in surgical freedom via endoscopic Denker's and prelacrimal approaches., Methods: Six cadaveric specimens (12 sides) were dissected using a prelacrimal approach on one side and an endoscopic Denker's approach on the contralateral side. The contents of the PPF and ITF were sequentially exposed. Surgical freedom for each corridor was subsequently calculated., Results: This study confirms that both the prelacrimal and Denker's approaches provide adequate exposure of the PPF and ITF. The maximum exposure boundaries were similar for both approaches, including the middle cranial fossa superiorly, floor of the maxillary sinus inferiorly, zygomatic arch and temporomandibular joint laterally, and post-styloid space posteriorly. However, the data revealed a statistically significant difference ( p  < 0.05) regarding the surgical freedom of the prelacrimal (388.17 ± 32.86 mm 2 ) and the endoscopic Denker's approaches (906.35 ± 38.38 mm 2 )., Conclusion: When compared with an endoscopic Denker's approach, a prelacrimal approach seems to achieve a similar extent of exposure (ie, visualization) of the PPF and ITF. Nonetheless, the endoscopic Denker's approach offers superior surgical freedom ; thus, it is preferred for the management of complex lesions which requires increased instrument maneuverability with a 3- or 4-handed technique.

Infratemporal and pterygopalatine fossae (ITF and PPF) represent two complex paramedian skull base areas, which can be defined as jewelry boxes, containing a large number of neurovascular and osteomuscular structures of primary importance. They are in close communication with many craniofacial areas, such as nasal/paranasal sinuses, orbit, middle cranial fossa, and oral cavities. Therefore, they can be involved by tumoral, infective or inflammatory lesions spreading from these spaces. Moreover, they can be the primary site of the development of some primitive tumors. For the deep-seated location of ITF and PPF lesions and their close relationship with the surrounding functional neuro-vascular structures, their surgery represents a challenge. In the last decades, the introduction of the endoscope in skull base surgery has favored the development of an innovative anterior endonasal approach for ITF and PPF tumors: the transmaxillary-pterygoid, which gives a direct and straightforward route for these areas. It has demonstrated that it is effective and safe for the treatment of a large number of benign and malignant neoplasms, located in these fossae, avoiding extensive bone drilling, soft tissue demolition, possibly unaesthetic scars, and reducing the risk of neurological deficits. However, some limits, especially for vascular tumors or lesions with lateral extension, are still present. Based on the experience of our multidisciplinary team, we present our operative technique, surgical indications, and pre- and post-operative management protocol for patients with ITF and PPF tumors.

Abstract: In Somalia, which is located in the horn of Africa, a fragile and insecure state structure allowed the strengthening of terrorist groups provoking armed conflicts. Stray bullet injuries can be defined as an accidental bullet wound caused by an anonymous attacker and are usually associated with celebratory gunfire or urban violence. The anatomy of the pterygopalatine fossa (PPF) is complex and penetrating foreign body injuries pose even a greater challenge for the surgeon to operate in this area. Endoscopic approaches facilitate the removal of foreign bodies from the paranasal sinuses, orbital cavity, and aerodigestive system, minimizing potential risks. This study presents a series of removal of stray bullets found in the PPF, as a result of urban violence in Somalia in a period of 6 months. Patient demographics, foreign body origin, treatment modalities, and surgery details were evaluated and assessed. All patients were male and aged 16, 2, and 24 years, respectively. The surgeries were quite straightforward with surgery times recorded as 25, 44, and 22 minutes, respectively. The endoscopic endonasal approach proved to provide safe and sufficient access for removal. Surprisingly, even the foreign body in the PPF of a 2-year-old patient could be removed with an endoscopic endonasal approach and did not require an external approach. The management of foreign body removal in the PPF is challenging due to the potential risks of iatrogenic vascular and nervous tissue injury. The endoscopic endonasal approach for removal proved efficient in 3 cases regardless of age and anatomical dimensions., Competing Interests: The authors declare no conflict of interest., (Copyright © 2021 by Mutaz B. Habal, MD.)

Competing Interests: The authors report no conflicts of interest.

Aim: To describe a new, minimally invasive, and safe access to foramen rotundum via the endoscopic endonasal trans-sinusoidal route for trigeminal nerve blockage., Material and Methods: We studied 5 fresh cadavers bilaterally, and 10 pterygopalatine fossae and maxillary nerves using the endoscopic endonasal trans-sinusoidal trans-pterygopalatine approach., Results: The proposed approach enabled the maxillary nerve to be visualized after revealing the foramen rotundum with the help of some craniometric measurements. Distance between sphenoid sinus lateral wall and maxillary sinus posterior wall was measured. This measurement was found to be an important triangulation point to determine the location of the entrance to the pterygopalatine fossa. The distance between the foramen rotundum and the sphenopalatine artery was found to be significant. The foramen rotundum diameter was calculated, and the maxillary nerve was found to be situated inferolateral to the foramen rotundum. Therefore, the safe entry zone was determined superomedially. No significant difference was found between male and female and the right and left nostrils., Conclusion: Various surgical procedures have been applied to treat drug-resistant trigeminal neuralgia. Nevertheless, their cure rates remain less than anticipated. Recurrences up to 30% have been reported in the literature. In this study, the endoscopic endonasal transmaxillary trans-pterygopalatine route offers a new perspective on the foramen rotundum approach and provides a panoramic and safe view in previously high-risk percutaneous interventions.

The pterygopalatine fossa contains a dense and complex array of neurovascular structures vulnerable to accidental surgical injury. This study aims to describe a novel landmark, the orbito-pterygo-sphenoidal ligament (OPSL), and implications of this structure for surgery in the pterygopalatine fossa and the inferior orbital fissure. Six cadaveric specimens (12 sides) were dissected using an endonasal approach to expose the periosteal layers associated with the pterygopalatine fossa and orbit. The thickened triangular-shaped ligament at their confluence was termed the OPSL. Dimensions of its lateral, inferior, and medial borders were measured, and their anatomical relationships defined. The pterygopalatine ganglion and the maxillary nerve lie immediately inferior and deep into the OPSL. The superior aspect of the posterior nasoseptal artery and nerve are covered by the medial OPSL. The lateral and inferior borders of the OPSL are contiguous with the periorbita and the periosteum of the pterygopalatine fossa, respectively. Along the medial border of the ligament, the openings of the palatovaginal fissure, vidian canal, and foramen rotundum were sequentially identified in a medial to lateral trajectory. The length of the lateral, inferior, and medial borders of the triangular OPSL were 13.25 ± 0.62, 14.25 ± 0.45, and 12.08 ± 0.90 mm, respectively. The OPSL is a thick, triangular-shaped fascial confluence, which may serve as a landmark for procedures within the pterygopalatine fossa and the inferior orbital fissure., (© 2021 Wiley Periodicals LLC.)

The pterygopalatine fossa and infratemporal fossa are spaces located under the skull base, housing important neurovascular structures. Surgical access to these spaces is challenging because of their deep location and complex anatomy. Their surgical access has been classically carried out through multiple craniofacial approaches until the advent of endoscopic endonasal surgery at the end of the XX th century. Our goal is to describe the transmaxillary-transsphenoidal-transpterygoid approach to the pterygopalatine and infratemporal fossae through endonasal endoscopic surgery based on anatomo-surgical dissection and an illustrative clinical case. We conclude that after careful radiologic evaluation of the feasibility of this technique, the endonasal endoscopic access to these spaces for tumor resection is efficient with reduced surgical morbidities. The endonasal approach is versatile and can be fashioned according to the nature and extent of the lesion., (Copyright © 2020 Elsevier Masson SAS. All rights reserved.)

Objective: To demonstrate the utility and limitations of the extradural endoscopic-assisted anterior temporal fossa approach to the pterygopalatine fossa (PPF), infratemporal fossa (ITF), paranasal sinuses (PS), parapharyngeal region (PPR), nasal cavities (NC), epipharynx (EP), and clivus., Methods: A frontotemporal orbitozygomatic craniotomy is performed. The dura is elevated from the cavernous sinus (CS). The anterior temporal fossa floor is drilled. Foramen rotundum and ovale are opened. The PPF is exposed and the lateral margin of inferior orbital fissure (IOF) is removed. The anterolateral triangle (ALT) is drilled and the vidian nerve (VN) is exposed. Drilling between the maxillary nerve (V2) and the VN provides access to the sphenoid sinus (SphS). The medial pterygoid plate is drilled exposing the EP. The maxillary sinus (MaxS) is opened anterior to the PPF. V2 is transposed laterally to enlarge the anteriomedial triangle (AMT). The orbital muscle of Muller is removed as well as the medial margin of the IOF, which opens the SphS. Anteriorly, the posterior ethmoid air cells are opened. Morphometric measurements evaluating the size of the ALT were done and the PS, NC, EP were explored with the endoscope., Results: The ALT and AMT triangle provides a wide exposure of the PPF, ITF, PPR. In addition, those triangles represent a deep entry point to explore the PS, NC, and EP., Conclusion: The ALT and AMT are useful corridors to access to the SphS, MaxS, PS, NC, and EP via a transcranial approach. The use of the endoscope through this corridor widely extend the extradural anterior temporal fossa approach which may be considered as a valuable alternative to the extended endoscopic endonasal approach for selected skull base lesions extending both intracranial and into the PS, NC and EP., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

Abstract: Surgical removal of pterygopalatine fossa (PPF) tumors with endoscopic endonasal approach is still challenging. The present study aimed to evaluate our endoscopic endonasal management of PPF tumors based on the tumor pathology and purpose of the surgery. This comprised both a single nostril approach for biopsy and a binostril approach for complete resection of benign and noninfiltrating tumors. Based on this strategy, 12 patients underwent endoscopic endonasal surgery for PPF tumors between 2013 and 2018. The patients' data were analyzed retrospectively to demonstrate the significance of our treatment scheme. The surgery was terminated only after taking a biopsy specimen in 6 patients. Other 6 patients underwent gross total resection or bulk tumor reduction. Final pathological diagnosis was malignant in 6 cases and benign in the remaining 6. Post-operative treatment was needed in 7 patients. Four operations for the 6 patients who underwent either debulking or radical surgery were performed by the binostril approach; while 5 surgeries for the 6 biopsy patients were performed by the single nostril approach. Postoperative complications were tolerable. Endoscopic resection should be adopted preferentially for benign tumors that can be removed in a piecemeal fashion. However, as most malignant tumors were impossible to resect with a negative margin, priority should be given to tumor biopsy using an endoscopic approach, which is less invasive than an open approach, and an appropriate treatment customized to the pathological diagnosis should be administered., Competing Interests: The authors report no conflicts of interest., (Copyright © 2020 by Mutaz B. Habal, MD.)

Abstract: A 13-year-old Japanese boy with a 6-month history of bilateral nasal obstruction and a 3-week history of recurrent epistaxis from the right nose was admitted to our department. Nasal endoscopy revealed a reddish, smooth-walled tumor occupying the right nasal cavity. Computed tomography scan revealed a 3.5 × 4.5 × 7.0-cm heterogeneously enhancing mass involving the right nasal cavity and extending posteriorly to the nasopharynx, and laterally to the pterygopalatine fossa and the medial part of the infratemporal fossa. We diagnosed as juvenile nasopharyngeal angiofibroma with Radkowski classification stage IIC. The internal maxillary and ascending pharyngeal arteries were embolized with polyvinyl alcohol followed by Embosphere using a conventional Seldinger technique. En bloc resection was performed with an endoscopic ipsilateral endonasal and sublabial Caldwell-Luc transmaxillary approach under general anesthesia. As of 3 years postoperatively, no recurrence has been found. We report a child case of juvenile nasopharyngeal angiofibroma successfully treated with less invasive surgery with preoperative embolization., Competing Interests: The authors report no conflicts of interest., (Copyright © 2020 by Mutaz B. Habal, MD.)

Abstract: Recent advances in endoscopic intranasal technology have allowed for a safe approach to the pterygopalatine fossa lesion. However, we consider that there is still scope of improvement to approach a broader area with better operability and minimal invasiveness. A 51-year-old man underwent endoscopic endonasal surgery due to the recurrence of chordoma at the left pterygopalatine fossa. To access the lower and lateral part of the pterygopalatine fossa, we performed endoscopic endonasal transmaxillary removal via an inferior turbinate incision. During surgery, a wide operative field and good operability could be secured by inserting an endoscope from the right nostril through a window of the nasal septum. Subtotal removal of the tumor was achieved without any complication during the surgery. Endoscopic endonasal transinfraturbinate approach with nasoseptal window was effective in the removal of the pterygopalatine fossa tumor because it is less invasive and provides a good surgical view with better operability., Competing Interests: The author reports no conflicts of interest., (Copyright © 2020 by Mutaz B. Habal, MD.)

Purpose: This study aimed to locate the inferior end (Pti) and the superior end (Pts) of pterygomaxillary junction (PMJ) relative to anterior nasal spine (ANS) so as to provide references for pterygomaxillary separation., Methods: The study was based on CBCT images of 109 Chinese patients. We projected Pti and Pts to the frontal plane and measured the distance as well as the positional relationship between the projection points and ANS via three-dimensional reconstruction image., Results: On average, the ANS was 5.18 mm above the Pti and the horizontal distance between the Pti and ANS was 21.86 mm. The horizontal and vertical distances between Pts and ANS was 20.41 mm and 10.91 mm, respectively. The vertical height of PMJ was 16.09 mm. Scatter plots diagrammatic centered on ANS showed that 73% (160/218) Pti and 64% (140/218) Pts appeared in a 45° fan shape ranged from 20 to 25 mm radius in bilateral inferior and superior quadrant, respectively. There was no significant difference in the distance between both sides (P > 0.05)., Conclusion: During the pterygomaxillary disjunction, it exists a risk of injuring neurovascular bundle of the pterygopalatine fossa 16.09 mm above the lowest border of the pterygomaxillary junction. The region within a 45° fan shape ranged in 20-25 mm radius in inferior quadrant centered on ANS might be suitable for the osteotome position. The positional relationship especially between the ANS and Pti found in this study provides a reference for surgeons during pterygomaxillary disjunction.

Background: Superb knowledge of anatomy and techniques to remove the natural barriers preventing full access to the most lateral aspect of the skull base determines the ease of using the transpterygoid approach (ETPA) as the main gateway for all the coronal planes during endonasal surgeries., Methods: Throughout stepwise image-guided cadaveric dissections, we describe the surgical anatomy and nuances of the ETPA to the pterygopalatine fossa (PPF) and upper parapharyngeal space (UPPS)., Conclusion: The ETPA represents a lateral extension of the midline corridor and provides a valuable route to access the PPF/UPPS. Major landmarks for this EEA are the infraorbital canal, sphenopalatine foramen, and vidian nerve. It comprises the removal of the palatine bone, posterior wall of the maxillary sinus, and PPF transposition to drill the pterygoid process.

Background: Reconstruction of full thickness nasal defects usually requires different donor sites for the external skin envelope, structural elements, and internal nasal lining. In this paper we present a novel single site method for dual inner lining and skeleton repair for full thickness nasal defects with a composite nasoseptal flap and extended pedicle dissection., Methods: A 72-year-old male presented with a T4b melanoma involving the nasal dorsum and left upper lateral cartilage. Following full thickness resection, reconstruction was performed with a nasoseptal flap (NSF) with attached septal cartilage and vomer in conjunction with a paramedian forehead flap. Extended pedicle dissection into the pterygopalatine fossa allowed the NSF to fully cover the defect., Results: The nasal defect was fully corrected. There was no evidence of flap compromise or nasal valve stenosis at 1 month, 2 month, and 1 year follow-up visits., Conclusions: We present here the first successful application of a composite cartilage-osseous-mucosal NSF for multilayered nasal reconstruction. In appropriate patients, this technique may obviate the need for flaps or grafts from extranasal sources, limiting donor site morbidity.

Endoscopic transmaxillary approaches to remove juvenile nasopharyngeal angiofibromas (JNAs) have been described previously and are used for tumors that extend laterally in the pterygopalatine fossa (PPF) and infratemporal fossa (ITF). There is no previous description of robotic-assisted JNA removal in the literature. The video will demonstrate the success of this technique. Robotic transmaxillary approaches to the lateral PPF and ITF are easily achieved through an extended Caldwell-Luc antrostomy. Total operative time was 519 minutes. Total robotic operative time was 283 minutes. The endoscopic approach provided no assistance in tumor dissection or removal. Robotic-assisted transmaxillary JNA removal allows the operating surgeon to control the endoscope and to operate free of collisions from the robotic console while having an active assistant surgeon at the patient bedside. A video demonstrating the technique is found on Head & Neck's web site., (© 2020 Wiley Periodicals, Inc.)

The aim of this study was to provide volumetric data of the pterygopalatine fossa by semiautomatic segmentation based upon cone beam computed tomography.Cone beam computed tomography (CBCT) images of 100 patients were analyzed. By using the open source software "ITK-Snap," the volumetric measurements of 200 pterygopalatine fossae were performed. For statistical investigations paired t test, and independent Student t test were performed. Also, the Pearsons chi-square test was applied. P values P < 0.05 were considered significant.The mean volume was 578.376 mm for the right and 560.979 mm for the left side. The results indicated statistically significant differences according to the right and the left pterygopalatine fossa, regardless of gender (P < 0.05). The analysis of differences between males and females did not show any significant results (P > 0.05), although males present a slightly larger volume than females. According to the median age (59 years), younger patients presented smaller volumes, whereas older patients presented larger volumes. Nevertheless, no statistically significant differences according to age (χ = 3.520; P > 0.05) could be found.Clinical intervention with the application of local anesthetics into the complex and vulnerable anatomy of the pterygopalatine fossa makes a thorough knowledge about the volumetric capacity indispensable. Therefore, the semiautomatic segmentation of CBCT images provides a useful, available and validated tool. Our results show that a final injected anesthetic volume larger than 1 ml exceeds the pterygopalatine fossa capacity considerably and could cause complications. To prevent this, volumetric analysis of this region can provide further information and enables an individualized patients' treatment.

A couple of cysts lying in the pterygopalatine fossa are rare. The authors report a case of a 28-year-old woman who was admitted to the authors' hospital with a 1-month history of headache and numbness on the left head. Three-dimensional computed tomography revealed a large soft mass in the pterygopalatine fossa. Magnetic resonance imaging showed that there were a couple of cysts in the pterygopalatine fossa. One cyst measured 41 × 38 × 34 mm and the other 23 × 19 × 19 mm. A transpterygoid transnasal endoscopic approach and resection of the lesion was performed. The authors opened the cyst with coblation and the lesion showed a lot of transparent thick yellow liquid. The authors located the posterior wall the other cyst with ENT image navigation. The puncture was conducted and a lot of yellow liquid flowed out of the lesion. The patient recovered rapidly. The headache and numbness were alleviated and disappeared after 1 month. The patient currently has no evidence of recurrence at 1 year postoperatively. The coblation and ENT image navigation make the surgeon more easily to achieve risk-free surgery under endoscopy.

Background: To identify the clinical characteristics and prognostic factors of malignancies involving the pterygopalatine fossa (PPF)., Methods: Fifty-seven patients who underwent curative surgery for malignant tumor involving PPF were reviewed., Results: The rates for three-year local control (LC), five-year disease-free survival (DFS) and five-year overall survival (OS) were 55.4%, 34.5%, and 52.7%, respectively. Perineural invasion (PNI) of the maxillary nerve with facial numbness (symptomatic V2 PNI) (P = .04) and cranial involvement (P = .03) were predictors for poor OS. Symptomatic V2 PNI was also a significant predictor for poor LC (P = .05) and DFS (P = .03). Within the subgroup analysis of patients with pathologically confirmed V2 PNI, asymptomatic V2 PNI patients had significantly better LC (71.2% vs 31.8%, P = .05) and DFS (43.8% vs 17.3%, P = .05) compared to symptomatic patients., Conclusion: Malignant tumors involving the PPF have diverse pathologies and a poor prognosis. Symptomatic V2 PNI may be an independent poor prognostic factor., (© 2019 Wiley Periodicals, Inc.)

Background: Surgical access to the second (V2, maxillary) and third (V3, mandibular) branches of the trigeminal nerve (V) has been classically through a transoral approach. Increasing expertise with endoscopic anatomy has achieved less invasive, more efficient access to skull base structures. The authors present a surgical technique using an endoscopic endonasal approach for the treatment of painful V2 neuropathy., Methods: Endoscopic endonasal dissections using a transmaxillary approach were performed in four formalin-fixed cadaver heads to expose the V2 branch of the trigeminal nerve. Relevant surgical anatomy was evaluated and anatomic parameters for neurectomy were identified., Results: Endoscopic endonasal transmaxillary approaches completed bilaterally to the pterygopalatine and pterygomaxillary fossae exposed the V2 branch where it emerged from the foramen rotundum. The anatomy defined for the location of neurectomy was determined to be the point where V2 emerged from the foramen rotundum into the pterygopalatine fossa. The technique was then performed in 3 patients with intractable painful V2 neuropathy., Conclusions: In our cadaveric study and clinical cases, the endoscopic endonasal approach to the pterygopalatine fossa achieved effective exposure and treatment of isolated V2 painful neuropathy. Important surgical steps to visualize the maxillary nerve and its branches and key landmarks of the pterygopalatine fossa are discussed. This minimally invasive approach appears to be a valid alternative for select patients with painful V2 trigeminal neuropathy.

Background: Various pathologies, including cerebrospinal fluid leaks and meningoencephaloceles, may arise in the lateral recess of the sphenoid sinus (LRSS), which may be accessed via an endonasal transpterygoid approach. The objective of this study was to evaluate the feasibility of accessing the LRSS via an endoscopic prelacrimal approach. Furthermore, we hypothesized that this approach may protect the pterygopalatine ganglion and vidian nerve., Methods: Five cadaveric heads (9 sides) with a well-pneumatized LRSS were identified and an endonasal prelacrimal approach was performed. The infraorbital nerve, at the orbital floor, served as a critical landmark. After identification of the foramen rotundum at the pterygoid base, the vascular compartment of the pterygopalatine fossa and the pterygopalatine ganglion were displaced inferomedially and superomedially, respectively. Drilling of the bone inferomedial to the foramen rotundum allowed entry into the LRSS., Results: The average distances from the prelacrimal window to the pterygoid base and the posterior wall of the LRSS were 6.22 ± 0.39 cm and 7.16 ± 0.50 cm, respectively. The average areas of the bony prelacrimal window and pterygoid base window were 4.33 ± 0.32 cm 2 and 0.73 ± 0.10 cm 2 , respectively. The LRSS could be accessed using a 0-degree endoscope, and pterygopalatine neurovascular structures, including the pterygopalatine ganglion and vidian nerve, could be preserved on all 9 sides., Conclusion: Our findings suggest that an endonasal prelacrimal approach provides a reasonable alternative to access the LRSS while preserving the vidian nerve and pterygopalatine ganglion., (© 2019 ARS-AAOA, LLC.)

Objectives/hypothesis: Releasing the nasoseptal flap (NSF) pedicle from the sphenopalatine artery (SPA) foramen may considerably improve flap reach and surface area. Our objectives were quantify increases in pedicle length and NSF reach through extended pedicle dissection into the pterygopalatine fossa (PPF) through cadaveric dissections and present clinical applications., Study Design: Anatomical study and retrospective clinical cohort study., Methods: Twelve cadaveric dissections were performed. Following standard NSF harvest, the distance from the anterior edge of the flap to the anterior nasal spine while pulling the flap anteriorly was measured. As dissection into the SPA foramen and PPF continued, similar interval measurements were completed in four stages after release from the SPA foramen, release of the internal maxillary artery (IMAX), and transection of the descending palatine artery (DPA). The extended pedicle dissection technique was performed in seven consecutive patients for a variety of different pathologies., Results: The mean length of the NSF from the anterior nasal spine and maximum flap reach were 1.91 ± 0.40 cm/9.3 ± 0.39 cm following standard harvest, 2.52 ± 0.61 cm/9.75±1.06 cm following SPA foramen release, 4.93 ± 0.89 cm/12.16 ± 0.54 cm following full IMAX dissection, and 6.18 ± 0.68 cm/13.41 ± 0.75 cm following DPA transection. No flap dehiscence or necrosis was observed in all seven surgical patients., Conclusions: Extended pedicle dissection of the NSF to the SPA/IMAX markedly improves the potential length and reach of the flap. This technique may provide a feasible option for reconstruction of large anterior skull base and craniocervical junction defects. Seven successful cases are presented here, but further studies with larger series are warranted to validate findings in a clinical setting., Level of Evidence: 4 Laryngoscope, 130:18-24, 2020., (© 2019 The American Laryngological, Rhinological and Otological Society, Inc.)

Background: Surgery remains the mainstay of treatment for lesions in the parapharyngeal space. However, gaining access to the parapharyngeal space is often challenging. In this study we aim to describe a minimally invasive technique of approaching the upper parapharyngeal space through an endoscopic transnasal retropterygoid approach, based on anatomic studies and surgeries., Methods: Six fresh human cadaver heads were prepared for anatomic study at the Surgical Neuroanatomy Laboratory of the Center for Cranial Base Surgery within the Department of Neurological Surgery at the University of Pittsburgh School of Medicine. Three clinical cases seen in the Department of Otolaryngology, Eye, Ear, Nose, and Throat Hospital, Shanghai Medical College of Fudan University, were used to illustrate the technique and feasibility of this approach and to assess its indications, advantages, and drawbacks., Results: The medial pterygoid plate is the primary landmark of the endoscopic transnasal retropterygoid approach to the upper parapharyngeal space. Access to the upper parapharyngeal space could be obtained by removing the mucosa on the medial pterygoid plate and the mucosa below the pharyngeal orifice of the Eustachian tube. The 3 patients in our study tolerated the procedure well and had no serious complications after surgery., Conclusion: The anatomic data and clinical cases in this study confirm that an endoscopic transnasal retropterygoid approach is a feasible and effective surgical treatment for selected tumors in the upper parapharyngeal space., (© 2019 ARS-AAOA, LLC.)

Hydatid cyst (echinococcosis) is an infectious disease caused mainly by Echinococcus granulosus, a parasite transmitted by dogs and encountered first in the liver and then in the lungs. Involvement in the head and neck region is uncommon, and pterygopalatine fossa disease resulting from hydatid cyst is extremely rare, with only 4 reported patients. In this report, the authors present a patient with exophthalmus caused by a primary hydatid cyst and involving the pterygopalatine fossa which treated only with endoscopic endonasal approach.

Background: Endoscopic transorbital approach (eTOA) has been announced as an alternative minimally invasive surgery to skull base. Owing to the inferior orbital fissure (IOF) connecting the orbit with surrounding pterygopalatine fossa (PPF), infratemporal fossa (ITF), and temporal fossa, the idea of eTOA to anterolateral skull base through IOF is postulated. The aim of this study is to access its practical feasibility., Methods: Anatomical dissections were performed in five human cadaveric heads (10 sides) using 0-degree and 30-degree endoscopes. A stepwise description of eTOA to anterolateral skull base through IOF was documented. The anterosuperior corner of the maxillary sinus in the horizontal plane of the upper edge of zygomatic arch was defined as reference point (RP). The distances between the RP to the foramen rotundum (FR), foramen ovale (FO), and Gasserian ganglion (GG) were measured. The exposed area of anterolateral skull base in the coronal plane of the posterior wall of the maxillary sinus was quantified., Results: The surgical procedure consisted of six steps: (1) lateral canthotomy with cantholysis and preseptal lower eyelid approach with periorbita dissection; (2) drilling of the ocular surface of greater sphenoid wing and lateral orbital rim osteotomy; (3) entry into the maxillary sinus and exposure of PPF and ITF; (4) mobilization of infraorbital nerve with drilling of the infratemporal surface of the greater sphenoid wing and pterygoid process; (5) exposure of middle cranial fossa, Meckel's cave, and lateral wall of cavernous sinus; and (6) reconstruction of orbital floor and lateral orbital rim. The distances measured were as follows: RP-FR = 45.0 ± 1.9 mm, RP-FO = 55.7 ± 0.5 mm, and RP-GG = 61.0 ± 1.6 mm. In comparison with the horizontal portion of greater sphenoid wing, the superior and inferior axes of the exposed area were 22.3 ± 2.1 mm and 20.5 ± 1.8 mm, respectively. With reference to the FR, the medial and lateral axes of the exposed area were 11.6 ± 1.1 mm and 15.8 ± 1.6 mm, respectively., Conclusions: The eTOA through IOF can be used as a minimally invasive surgery to access whole anterolateral skull base. It provides a possible resolution to target lesion involving multiple compartments of anterolateral skull base.

The vomerovaginal canal (VVC) and palatovaginal canal (PVC) are two canals that open forward to the posterior wall of the pterygopalatine fossa (PPF). Although the anatomy and computed tomography (CT) appearances of the PVC have been well studied, the VVC has been rarely reported, especially in endoscopic examinations. Some studies have even failed to distinguish the PVC from the VVC on CT images. The purpose of this study was to demonstrate the anatomy of the VVC on endoscopy and reveal its differences from the PVC, and to analyse the relative positions of the VVC, PVC, and pterygoid canal on CT images. Ten dry skull bases were studied to observe the structures involved in the formation of the VVC. Dissection of four cadaveric heads was performed to demonstrate the anatomy of the VVC on endoscopy. Coronal CT image analysis in 70 patients was conducted to evaluate the distances and relative positions between the VVC, PVC, and pterygoid canal. The PVC and VVC were also compared on axial CT images. The osteological study showed the top wall of the VVC was the antero-inferior wall of the sphenoid sinus. The VVC may be a helpful landmark in endoscopic endonasal transpterygoid approaches. Steps and discrimination in the dissections of the VVC and PVC were described. The interval between the PVC and VVC could be observed on both coronal and axial CT images. The coronal CT images of patients showed differences in the positions and distances among the three canals at both the anterior and posterior apertures of the PVC. The VVC can be easily mistaken for the PVC if its existence is not suspected. The anatomical morphologies and trajectories of the VVC and PVC differed on both nasal endoscopy and CT. The existence of the VVC should be considered during surgery and CT diagnosis within this area., (© 2019 Anatomical Society.)

Background: The endoscopic transnasal approach has been proven to have advantages on the removal of the tumors in pterygopalatine fossa (PPF) and infratemporal fossa (ITF). Herein, this study aimed to describe a modified approach for resection of the tumors in these areas, both in cadaveric specimen and clinical patients., Methods: The 20 adult cadaveric specimens and five patients with tumors in PPF and ITF were enrolled in this study. For the cadaveric specimens, ten were simulated anterior transmaxillary approach and ten were performed modified endoscopic transnasal transmaxillary approach. The exposure areas were compared between two groups and main anatomic structure were measured. Surgery was operated in the five patients with tumors of PPF and ITF to verify the experience from the anatomy. Perioperative management, intraoperative findings and postoperative complications were recorded and analyzed., Results: The modified endoscopic transnasal transmaxillary approach provided as enough surgical exposure and high operability to the PPF and ITF as the anterior transmaxillary approach did. The diameter of maxillary artery in the PPF was 3.77 ± 0.78 mm (range: 2.06-4.82 mm), the diameter of middle meningeal artery in the ITF was 2.79 ± 0.61 mm (range: 1.54-3.78 mm). Four patients who suffered schwannoma got total removal and one of adenocystic carcinoma got subtotal removal. The main complications were facial numbness and pericoronitis of the wisdom tooth. No permanent complication was found., Conclusions: With the widespread use of neuroendoscopy, the modified endoscopic transnasal transmaxillary approach is feasible and effective for the resection of tumors located in PPF and ITF, which has significant advantages on less trauma and complications to the patients.

Selecting an appropriate surgical approach for resection of huge skull base tumors involving pterygopalatine and infratemporal fossa is challenging because of their rarity and high possibility of vital anatomical structure injuries. To suggest the guidance of selecting the appropriate approach by analyzing outcomes and satisfactions of known surgical approaches with our previous experience, the authors retrospectively analyzed skull base tumor cases experienced for 24 years, and condensed to 4 well-known surgical approaches: maxillary swing, infratemporal fossa type C, transzygomatic, and a combined transzygomatic-midfacial degloving approach: to review indications, advantages, and limitations of these approaches. Maxillary swing approach was useful in large-sized tumors as it provided wide surgical field; however, inevitable facial scar was the main drawbacks, especially in adolescents. Infratemporal fossa approach type C was helpful in the involvement of vital vascular structures; however, long incision scar with temporal area depression and permanent conductive hearing loss were the factors of patients' dissatisfaction. Transzygomatic approach could be the good alternative to the infratemporal fossa approach type C; however, en bloc tumor resection was impossible due to its limited operative space. To overcome limitations of these approaches, transzygomatic approach was combined with midfacial degloving approach, and it enabled lateral and anterior access without prominent facial scar and/or deformity while providing wide surgical space. Based on our 24 years of surgical experience in managing huge skull base tumors, the authors recommend the combined transzygomatic-midfacial degloving approach, which enables complete resection with short postoperative healing periods and no disfiguring facial incisions.

Background:: Cervicofacial actinomycosis is an uncommon indolent infection caused by Actinomyces spp that typically affects individuals with innate or adaptive immunodeficiencies. Soft tissues of the face and neck are most commonly involved. Actinomyces osteomyelitis is uncommon; involvement of the skull base and temporal bone is exceedingly rare. The authors present a unique case of refractory cervicofacial actinomycosis with development of skull base and temporal bone osteomyelitis in an otherwise healthy individual., Methods:: Case report with literature review., Results:: A 69-year-old man presented with a soft tissue infection, culture positive for Actinomyces, over the right maxilla. Previous unsuccessful treatment included local debridement and 6 weeks of intravenous ceftriaxone. He was subsequently treated with conservative debridement and a prolonged course of intravenous followed by oral antibiotic. However, he eventually required multiple procedures, including maxillectomy, pterygopalatine fossa debridement, and a radical mastoidectomy to clear his disease. Postoperatively he was gradually transitioned off intravenous antibiotics., Conclusions:: Cervicofacial actinomycosis involves soft tissue surrounding the facial skeleton and oral cavity and is typically associated with a history of mucosal trauma, surgery, or immunodeficiency. The patient was appropriately treated but experienced disease progression and escalation of therapy. Although actinomycosis is typically not an aggressive bacterial infection, this case illustrates the need for prompt recognition of persistent disease and earlier surgical intervention in cases of recalcitrant cervicofacial actinomycosis. Chronic actinomycosis has the potential for significant morbidity.

The oral cancer with masticator-space involvement is classified as T4b disease. The limited data suggest that the masticator space is a complex anatomic area and tumors with varying degrees of infiltration may have different oncologic outcomes. It is not advisable to group all T4b tumors as one and consider them for palliative-intent treatment. A group of patients with limited spread (infra-notch) has potential for good outcome. These cancers can be considered for downstaging to T4a classification based on best available data and clinical considerations. The radical surgical resection remains the mainstay of curative-intent treatment and the ability to achieve negative margins at the skull base remains the most important prognostic factor. The alternative approaches to either increase radicality of surgery or to downsize the tumor with neoadjuvant therapies have shown encouraging trends but larger, well designed, and prospective studies will be needed to make meaningful conclusions. It is important to rationalize and form common ground for further research., (© 2018 Wiley Periodicals, Inc.)

Objective: The aim of this study was to identify key anatomic landmarks useful in gaining access to the anteromedial temporal region via the corridor formed by the inferior orbital fissure (IOF), the ophthalmic branch of the trigeminal nerve (V1), and the maxillary branch of the trigeminal nerve (V2) via an endoscopic endonasal approach (EEA)., Methods: An anatomic dissection of 6 cadaver heads was performed to confirm the feasibility and applicability of an EEA for accessing the anteromedial temporal region., Results: After middle turbinectomy, the lateral recess of the sphenoid sinus was opened, the orbital apex was exposed, and the posterior wall of the maxillary sinus was removed, in sequence. The IOF and the pterygopalatine fossa (PPF) were then identified. After opening the foramen rotundum (FR) and removing the bony structure between the FR, V2 was transposed downward. The orbital muscle of Müller was removed. The PPF was mobilized downward exposing the greater wing of the sphenoid bone (GWS). The GWS between V1 and V2 was drilled, therefore exposing the temporal dura. With blunt dissection, the medial temporal dura was peeled away from the cavernous sinus to increase access to the anteromedial temporal region., Conclusions: The anteromedial temporal fossa was exposed by drilling the V1-V2 triangle corridor via an EEA. Endoscopic endonasal exposure of the anteromedial temporal fossa is feasible and requires limited endonasal work. This approach may be considered as an alternate surgical corridor to the temporomesial lobe that offers the advantages of a direct route with less temporal lobe retraction., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background: Juvenile nasopharyngeal angiofibroma often attaches firmly to the adjoining bony region around the sphenopalatine foramina-sphenopalatine fossa-pterygomaxillary fissure. This can result in hourglass-shaped constriction and predispose to incomplete resection (residual disease) with a transpalatal approach. This paper describes attempts to address this 'inaccessible' area with a novel instrument, used since 2012., Methods: Measurements of the sphenopalatine foramen, nasal septum, posterior nasopharyngeal wall and hard palate were undertaken in 20 skulls and 10 computed tomography scans (lateral extension). A device was designed (in terms of angulation and length) following several trials with malleable wire. A search of patents was also undertaken. Recurrence rates were compared in cases of device use and non-use., Results: The novelty of the sphenopalatine fossa dissector was established and the device was patented. This device has significantly improved our 17.59 per cent recurrence rate of the past 4 decades; of 63 cases over 3 years, there were only 3 recurrences and 2 residual disease cases. Findings of our previous studies with or without the device are compared., Conclusion: Existing evidence supports the incorporation of this inexpensive instrument in the armamentarium for resecting lateral extension of juvenile nasopharyngeal angiofibroma during a transpalatal approach.

Objective: To describe an endoscopic anterolateral surgical route to the lateral portion of Meckel's cave., Methods: A sublabial transmaxillary transpterygoid approach was performed in 6 cadaveric heads (12 sides). A craniectomy was drilled between the foramen rotundum (FR) and foramen ovale (FO) with defined borders. Extradural dissection was performed up to the V2-V3 junction of the trigeminal ganglion. The working space was analyzed using anatomic measurements., Results: The approach allowed for extradural dissection to the lateral aspect of Meckel's cave and provided excellent exposure of V2, V3, and the V2-V3 junction at the gasserian ganglion. The mean distance between the FR and FO along the pterygoid process of the sphenoid bone was 21.3 ± 2.8 mm (range, 18-24.4 mm). The mean distance of V2 and V3 segments from their foramina to the gasserian ganglion junction was 12.0 ± 2.3 mm (range, 9.2-14.6 mm) and 15.2 ± 2.7 mm (range, 12.3-18.5 mm), respectively (6 sides). A potential working area (mean area, 89 mm 2 ) is described. Its superior edge is from the FR to the V2-V3 junction at the gasserian ganglion, its inferior edge is from the FO to the V2-V3 junction at the gasserian ganglion, and its base is from the FO to the FR. The surgical anatomy of the infratemporal fossa, pterygopalatine fossa, and lateral Meckel's cave is highlighted., Conclusions: An endoscopic anterolateral sublabial transmaxillary transpterygoid approach between the FR and FO avoids crossing critical neurovascular structures within the cavernous sinus and pterygopalatine fossa and can provide a safe surgical corridor for laterally based lesions in Meckel's cave., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Purpose: Surgically assisted rapid maxillary expansion (SARME) is a procedure routinely performed to correct transverse maxillary deformities and can be performed with or without pterygomaxillary disjunction (PD). The aim of the present study was to measure the effect of the amount of expansion and stability of SARME with or without PD., Patients and Methods: We designed and implemented a double-blind, randomized clinical trial. The patients were randomly assigned to 2 groups: group 1, SARME without PD; and group 2, SARME with PD. Cone-beam computed tomography scans were performed at 3 points: baseline (T0), after maxillary expansion (T1), and at the end of the retention period (T2). Dental and bone expansion and dental inclination at the maxillary canine and first molar regions were assessed. Two-way repeated measures analysis of variance was used to evaluate the differences between the 2 groups at the 3 evaluation periods (T0, T1, and T2), using a level of significance of P < .05., Results: A total of 24 patients underwent maxillary surgical expansion (group 1, n = 12; and group 2, n = 12). Both techniques promoted a significant transverse dental expansion in the first molar at T2 (with PD, 5.4 mm; vs without PD, 6.4 mm; change, -6.18 mm to 1.48 mm). However, no statistically significant differences were observed between the 2 groups. The tipping molars at T2 remained at a higher level in the SARME, no PD group than in the SARME, PD group (with PD, 2.3°; vs no PD, 4.6° for 3 teeth; change, -12.72° to 5.57°; and with PD, 1.6° vs without PD, 3.6° for 14 teeth; change, -9.96° to 9.83°)., Conclusions: SARME with and without PD is a reliable method for obtaining maxillary expansion, with slight differences in the patterns of skeletal and dental alterations., (Copyright © 2017 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

The current study aimed at comparing the number and type of undesired outcomes during and after the maxillary expansion performed with HYRAX and HAAS expanders. A total of 90 patients (41 males and 49 females, 45.6% and 54.4%, respectively) aged 18 to 59 (mean age of 26.1; standard deviation [SD] = 7.4) underwent subtotal Le Fort I osteotomy and pterygomaxillary disjunction following surgically assisted rapid maxillary expansion (SARME) carried out using HAAS (n = 29; 48.3% male and 51.7% female; mean age = 27: SD = 7.7) and HYRAX (n = 61; 44.3% male and 55.7% female; mean age = 26; SD = 7.2) expanders. Post-SARME dento-gingival, radiographic, and clinical undesired outcomes were evaluated. A total of 16 (17.8%) patients experienced at least 1 undesired outcome-7 (7.8%) and 9 (10.0%) in HAAS and HYRAX group, respectively. The most common undesired outcomes were radiographic asymmetric expansion-2 (2.2%) and 3 (3.3%) in HAAS and HYRAX group, respectively-followed by pain during out-of-clinic expansion 4 (4.4%) in HAAS group only-dental darkening 5 (5.5%) in HYRAX group, only, requiring root canal treatment, and local infection-2 (2.2%), 1 in each HAAS and HYRAX groups. Excepting for complications arising from the acrylic stop plate in HAAS expander, the number and severity of complications observed in the current study did not differ due to the use of HAAS and HYRAX appliances to perform maxillary expansion. Hygiene issues do not rule out the use of HAAS. The wider maxillary expansion performed, the more frequent are the cases of asymmetric expansion.