The application of 3-dimensional magnetic resonance imaging in nasopharyngeal carcinoma with pterygopalatine fossa invasion.

OBJECT: The pterygopalatine fossa (PPF) is a covert neurovascular pathway in the skull base and connects with numerous intracranial and extracranial spaces. The aim of this study was to explore the magnetic resonance imaging (MRI) features of PPF invasion in patients with nasopharyngeal carcinoma (NPC). MATERIAL AND METHODS: The medical records of 88 patients with stage T3 or T4 NPC were retrospectively analyzed. The 3-Dimensional (3D) volumetric images of MRI were reconstructed for the tiny connecting conduits of the invaded PPFs in the NPC patients. The infiltration incidence of conduits and connected further structures were calculated. RESULTS: Forty-six PPFs from 37 patients were invaded by NPC. The proportions of stage T4 NPC and intracranial extension were higher in patients with PPF invasion than that without PPF invasion (P < 0.05). Each connecting conduit of the PPF had corresponding optimal reconstructed orientation based on 3D volumetric MRI images. The first three most common infiltrated conduits were palatovaginal canal, vidian canal and sphenopalatine foramen, which were adjacent to the nasopharynx. Among the conduits connecting with further structures, the most common infiltrated conduit was pterygomaxillary fissure, followed by foramen rotundum and inferior orbital fissure. Furthermore, The NPC lesions involved stage T4 structures via the conduits from 19.6% of the invaded PPFs. CONCLUSIONS: The application of high-quality reconstruction images based on 3D sequence of MRI in NPC patients proved to be feasible and beneficial for the manifestation of the invaded PPFs and connecting conduits.

Infra-Temporal and Pterygo-Palatine Fossae Tumors: A Frontier in Endoscopic Endonasal Surgery-Description of the Surgical Anatomy of the Approach and Report of Illustrative Cases.

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.

Endoscopic Endonasal Surgery for Resection of a Pterygopalatine Fossa Malignant Peripheral Nerve Sheath Tumor: 2-Dimensional Operative Video.

The pterygopalatine fossa (PPF) is an inverted, pyramid-shaped space immediately behind the posterior wall of the maxillary sinus, and lesions arising here include juvenile angiofibromas, schwannomas, and, in exceptionally rare cases, malignant peripheral nerve sheath tumors.1,2 Surgical access to the PPF is challenging and has been historically achieved via an open transmaxillary approach associated with facial scaring/deformity as well as potential injury to facial and infraorbital nerve branches.3 We present the case of a 67-year-old woman with facial numbness secondary to a presumed trigeminal schwannoma in the right PPF on magnetic resonance imaging. This surgical video highlights the key stages in performing an endoscopic endonasal excision of a PPF tumor. We start with a wide medial maxillary antrostomy, mobilization of the inferior turbinate, ethmoidectomy, and sphenoidotomy. The posterior wall of the maxillary sinus is then lifted off the anterior aspect of the tumor. The soft tissue attachment medial to the tumor containing the sphenopalatine artery is then cauterized and divided. This is followed by circumferential blunt dissection of the tumor until it is sufficiently mobile to remove in a piecemeal fashion. The PPF is then examined for any residual tumor and any bleeding from the maxillary artery within the fat pad. Hemostasis and reattachment of the inferior turbinate into the lateral nasal wall is demonstrated. The patient did not have any new deficits postoperatively, but histology indicated a malignant peripheral nerve sheath tumor and she underwent postoperative proton beam therapy. Postoperative surveillance magnetic resonance imaging at 14 months showed no tumor recurrence. The patient consented to the procedure in a standard fashion (Video 1).

Primary yolk sac tumor of pterygopalatine fossa with loss of vision: A case report.

INTRODUCTION: Primary yolk sac tumor (YST) is an infrequently-diagnosed malignant extragonadal germ cell tumors. It is likely to recur locally and may present with widespread metastases once diagnosed. Primary YST of the head is uncommon but can cause severe complications, such as loss of vision once the tumor mass invades the optic nerve. PATIENT CONCERNS: A 20-month-old boy presented to the general clinic of the local children's hospital with a complaint of swelling of left face for 1 year and proptosis of the left eye for over 2 weeks as stated by his parents. Initially, he did have some vision, as he could walk by himself, but a special ophthalmologic examination was not performed. DIAGNOSES: Cranial computed tomography and magnetic resonance imaging revealed a large tumor accompanied by peripheral bone destruction in the left pterygopalatine fossa that extended to sphenoid, ethmoid, left maxillary sinuses, left nasoethmoid, and left orbit. The optic nerve was invaded on both sides. Chest and abdominal imaging were normal. A primary diagnosis of Langerhans cell hyperplasia was made. However, blood tests on the second day of hospitalization revealed significantly elevated serum alpha-fetoprotein levels. On the third day, the boy lost his eyesight, with loss of pupillary and no light sensation during flashlight stimulation on both sides. INTERVENTIONS: Nasal endoscopy was performed on the fourth day, the vast majority of soft tissue mass was resected for biopsy. Histopathological examination revealed features of endodermal sinus tumor. A final diagnosis of primary YST of pterygopalatine fossa was made. Because the mass could not be resected completely, he received combined chemotherapy with bleomycin, etoposide, and carboplatin for 6 cycles over six months. OUTCOMES: The patient recovered with significant tumor shrinkage and without secondary metastasis after 18 months but left permanently blind. CONCLUSION: The worst complication of loss of vision after Primary YST of pterygopalatine fossa alerts us that close physical examination during the initial investigation should be performed, which is especially important in young children who cannot express complaints well. Early detection and treatment with surgical resection and chemotherapy may contribute to satisfactory outcomes and avoidance of visual impairment.

Evolution of transmaxillary approach to tumors in pterygopalatine fossa and infratemporal fossa: anatomic simulation and clinical practice.

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 ±â€Š0.78 mm (range: 2.06-4.82 mm), the diameter of middle meningeal artery in the ITF was 2.79 ±â€Š0.61 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.

Juvenile nasopharyngeal angiofibroma in prepubertal males: A diagnostic dilemma.

OBJECTIVES/HYPOTHESIS: To highlight the presentation and management of juvenile nasopharyngeal angiofibroma (JNA) in prepubertal children. STUDY DESIGN: Single-institution 10-year retrospective review. METHODS: All identified cases of pathologically confirmed JNA in children <10 years of age were assessed from a gender, imaging and embolization findings, tumor stage, surgical approach, and clinical outcomes standpoint, and compared to a group of stage-matched older patients from the same time period. RESULTS: Of 45 patients over the 10-year study period, four male children between 8 to 9.8 years of age were identified. One patient had University of Pittsburgh Medical Center stage 1 disease, and the other three had stage 3 disease at presentation. A malignant process other than JNA was of concern preoperatively in two of the four children due to a combination of aggressive imaging characteristics and an absence of pterygopalatine fossa involvement. Such pterygopalatine fossa involvement was comparatively uniformly present in a group of stage-matched JNA patients aged 15 to 21 years. All four prepubescent children underwent surgical resection via transnasal endoscopic approach following ipsilateral sphenopalatine artery embolization without the need for blood transfusion. There were no recurrences in three of the four cases at a median follow-up duration of 2.3 years (range, 0.8-6.4 years). CONCLUSIONS: JNA may pose a diagnostic challenge in prepubertal males due to the atypical age at presentation and absence of classic imaging characteristics. Successful endoscopic transnasal resection is possible despite anatomic constrictions. LEVEL OF EVIDENCE: 4 Laryngoscope, 129:1777-1783, 2019.

Oral cancer involving masticator space (T4b): Review of literature and future directions.

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.

An Alternative Endoscopic Anterolateral Route to Meckel's Cave: An Anatomic Feasibility Study Using a Sublabial Transmaxillary 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 mm2) 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.

Primitive Squamous Cell Carcinoma of Pterygopalatine Fossa.

Primitive tumors of pterygopalatine fossa (PPF) are often benign tumors or extension of a malignant sinonasal tract. Primitive tumors may rarely occur in PPF.The authors present a 71-year-old woman with a 6-month history of left cranial nerve palsy. Magnetic resonance imaging and positron emission tomography-computed tomography showed an enhancing isolated lesion at the PPF. A transmaxillary biopsy was performed, leading to diagnosis of primitive squamous cell carcinoma. The patient underwent radiotherapy treatment.Primitive tumors of PPF are rare and diagnosis may be difficult. Endoscopic access for diagnosis can be performed. Squamous cell carcinoma occurring in PPF is associated with poor prognosis.

Endoscopic Endonasal Craniofacial Surgery for Recurrent Skull Base Meningiomas Involving the Pterygopalatine Fossa, the Infratemporal Fossa, the Orbit, and the Paranasal Sinus.

OBJECTIVE: Skull base meningiomas carry a nonnegligible risk of recurrence. In particular, those arising from the sphenoid wings or middle cranial fossa penetrate into extracranial regions, uncommonly showing massive expansion into the craniofacial regions on recurrence. The role of endoscopic endonasal surgery for those intractable lesions remains unclear. METHODS: We performed endoscopic endonasal craniofacial surgery for 8 recurrent meningiomas invading into the pterygopalatine fossa, infratemporal fossa, nasopharynx, paranasal sinus, or orbit, comprising 2 meningothelial and 1 fibrous meningiomas (World Health Organization [WHO] grade I), 3 atypical and 1 clear cell meningiomas (grade II), and 1 anaplastic meningioma (grade III). All were large (15-80 cm3; median, 45 cm3) and highly vascularized. RESULTS: All 8 tumors were sufficiently resected. Gross total resection of the craniofacial part of the lesions was achieved in 5 patients (62.5%). In 3 patients with WHO grade I meningiomas and 1 with grade II, tumors were successfully controlled as of the last follow-up. In 4 patients with WHO grade II or III meningiomas, craniofacial lesions were controlled, whereas original intracranial lesions were poorly controlled and became critical. CONCLUSIONS: We consider the endoscopic endonasal approach as an acceptable, less-invasive alternative for recurrent craniofacial meningioma. Although all these cases were relatively large and highly vascularized, preoperative endovascular embolization of the feeding arteries contributes to significantly reducing vascularity of the tumors, and local control of the craniofacial lesions was successfully achieved in all cases. Endoscopic endonasal craniofacial surgery enabled sufficient mass reduction without disfiguring facial incisions.

Targeted next-generation sequencing of malignant peripheral nerve sheath tumor of the pterygopalatine fossa with intracranial metastatic recurrence.

Malignant peripheral nerve sheath tumor (MPNST) is an uncommon neoplasm that rarely involves the head and neck region. Intracranial MPNSTs unrelated to cranial nerves are highly malignant tumors with poor overall survival, probably because of infiltrating growth into surrounding brain tissue. The pathogenesis of MPNST remains unclear. There are no conclusive explanations for the mechanisms underlying the initiation, progression, and metastasis of MPNST. In this paper, we describe a case of MPNST in the pterygopalatine fossa with intracranial metastatic recurrence and review related literatures. Meanwhile, targeted next-generation sequencing (NGS) revealed the presence of both a beta-catenin (CTNNB1) missense mutation p.Ser33Phe and a mediator complex subunit 12 (MED12) frameshift mutation p.Tyr1278fs in the recurrent intracranial tumor. Therapies that target CTNNB1 mutation, MED12 mutation, CTNNB1 activation, or Wnt pathway activation are worth future studying.

Effects of Pterygomaxillary Separation on Skeletal and Dental Changes After Surgically Assisted Rapid Maxillary Expansion: A Single-Center, Double-Blind, Randomized Clinical Trial.

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.

Endoscopic endonasal approach for mass resection of the pterygopalatine fossa.

OBJECTIVES: Access to the pterygopalatine fossa is very difficult due to its complex anatomy. Therefore, an open approach is traditionally used, but morbidity is unavoidable. To overcome this problem, an endoscopic endonasal approach was developed as a minimally invasive procedure. The surgical aim of the present study was to evaluate the utility of the endoscopic endonasal approach for the management of both benign and malignant tumors of the pterygopalatine fossa. METHOD: We report our experience with the endoscopic endonasal approach for the management of both benign and malignant tumors and summarize recent recommendations. A total of 13 patients underwent surgery via the endoscopic endonasal approach for pterygopalatine fossa masses from 2014 to 2016. This case group consisted of 12 benign tumors (10 juvenile nasopharyngeal angiofibromas and two schwannomas) and one malignant tumor. RESULTS: No recurrent tumor developed during the follow-up period. One residual tumor (juvenile nasopharyngeal angiofibroma) that remained in the cavernous sinus was stable. There were no significant complications. Typical sequelae included hypesthesia of the maxillary nerve, trismus, and dry eye syndrome. CONCLUSION: The low frequency of complications together with the high efficacy of resection support the use of the endoscopic endonasal approach as a feasible, safe, and beneficial technique for the management of masses in the pterygopalatine fossa.

Endoscopic endonasal approach for mass resection of the pterygopalatine fossa

OBJECTIVES: Access to the pterygopalatine fossa is very difficult due to its complex anatomy. Therefore, an open approach is traditionally used, but morbidity is unavoidable. To overcome this problem, an endoscopic endonasal approach was developed as a minimally invasive procedure. The surgical aim of the present study was to evaluate the utility of the endoscopic endonasal approach for the management of both benign and malignant tumors of the pterygopalatine fossa. METHOD: We report our experience with the endoscopic endonasal approach for the management of both benign and malignant tumors and summarize recent recommendations. A total of 13 patients underwent surgery via the endoscopic endonasal approach for pterygopalatine fossa masses from 2014 to 2016. This case group consisted of 12 benign tumors (10 juvenile nasopharyngeal angiofibromas and two schwannomas) and one malignant tumor. RESULTS: No recurrent tumor developed during the follow-up period. One residual tumor (juvenile nasopharyngeal angiofibroma) that remained in the cavernous sinus was stable. There were no significant complications. Typical sequelae included hypesthesia of the maxillary nerve, trismus, and dry eye syndrome. CONCLUSION: The low frequency of complications together with the high efficacy of resection support the use of the endoscopic endonasal approach as a feasible, safe, and beneficial technique for the management of masses in the pterygopalatine fossa.

Anatomical landmarks for maxillary nerve block in the pterygopalatine fossa: A radiological study.

INTRODUCTION: The aim of this study was to describe the anatomical landmarks for maxillary nerve block in the pterygopalatine fossa. The risk of injury to the skull base and maxillary artery was assessed. METHODS: This retrospective study was based on the analysis of 61 consecutive computed tomography angiographies obtained from patients suffering from different pathologies. Anatomical relationships between optic canal (OC), foramen rotundum (FR), inferior orbital fissure (IOF) and puncture point (PP) were assessed. A "maxillary section" was virtually carried out on the CTs, following a plane passing through PP, IOF and FR in order to mimic the anaesthesia needle route. RESULTS: No gender difference was observed except for the PP-OC distance that was longer in men. The mean PP-IOF distance was of 31.9 (± 0.7mm). PP-OC (43.9±0.5) and PP-FR (44.2±0.7) distances increased significantly with the patients height (PP-FR=17.25+0.16×height (cm); PP-OC=20.54+0.13×height (cm)). The route to the skull base was curved, with an angle of 168±1.6° at the FR level. The angle to reach the OC was greater than 7°. DISCUSSION: With a 35-mm needle length, the probability to reach the IOF was high (79%), while the risk to injure the skull base (2%) and the optical nerve (0%) was low. Artery injuries were only found in 13% of cases. Therefore, a 35-mm needle length allows for the best efficacy/risk ratio in maxillary nerve block.

Clarifying the mechanism of effect of the Bionator for treatment of maxillary protrusion: A percentile growth study.

AIM: The reported effects of Bionator treatment in patients with mandibular retrognathism are conflicting. This study evaluated the changes in craniofacial morphology resulting from treatment with a Bionator, based on measurement percentiles previously reported, to clarify the mechanism of the effect of this commonly used functional device. MATERIALS AND METHODS: Study Design: Retrospective. SETTING: A private orthodontic clinic. PARTICIPANTS: Forty-two children (mean age, 10.13 years) requiring treatment with a Bionator for Class II malocclusion (mandibular retrognathism). Children were randomly assigned to a Bionator group with or without an expansion screw. Measurements on lateral cephalometric radiographs were taken before and upon completion of Bionator treatment. All parameters measured were characterised according to the measurement percentiles previously reported. Each parameter was compared before and after treatment for all patients and for each treatment group using Wilcoxon's test. RESULTS: No significant differences in cranial length or mandibular body length were seen in any of the 3 groups, but anterior cranial base length and maxillary length were significantly decreased while mandibular ramus height and mandibular length were significantly increased after treatment in the Bionator with expansion screw group and in the all-patient group. CONCLUSIONS: The findings suggest that treatment with a Bionator with expansion screw during the growth and development stage results in increased mandible length and ramus height and inhibits the growth of the maxilla and anterior cranial base bone.

Modified partial maxillary swing approach for myxofibrosarcoma in pterygopalatine fossa.

BACKGROUND: Extirpation of tumors arising in the pterygopalatine fossa is challenging because of its anatomic complexity. METHODS AND RESULTS: A 67-year-old man was referred to our department with a diagnosis of a tumor in his left pterygoid fossa. An incisional biopsy through the canine fossa was diagnosed as myxofibrosarcoma. The upper part of the maxilla was swung laterally to remove the tumor while the hard plate was preserved. The defect was reconstructed using rectus abdominis musculocutaneous free and ipsilateral temporal. The postoperative course was uneventful, without facial palsy or mastication disorders. CONCLUSION: Our experience with this case suggests that the modified partial maxillary swing approach with preservation of the hard palate and orbital floor in combination with infratemporal and cervical approaches is useful for lesions in the pterygoid process without causing severe complications. © 2016 Wiley Periodicals, Inc. Head Neck 38: E2519-E2522, 2016.

Anatomical and radiological approach to pterygoid implants: a cross-sectional study of 202 cone beam computed tomography examinations.

The aim of this study was to define the three-dimensional angulation of the pterygomaxillary corridor in which pterygoid implants should ideally be placed. A secondary objective was to study the bone density in the tuberosity area and pterygoid plate. Two hundred and two cone beam computed tomography files of atrophic posterior maxillae were evaluated. Implant placement was guided by the individual anatomy of each patient. The mean implant angulation was 74.19±3.13° in the anteroposterior axis and 81.09±2.65° in the buccopalatal axis, relative to the Frankfort plane. Density in the tuberosity area ranged from 285.8 to 329.1DV units and density in the pterygoid plate area from 602.9 to 661.2DV units, with a 95% confidence interval. The density in the pterygoid area was 139.2% greater than in the tuberosity zone. Implant placement should be guided by the individual anatomy of each patient. Statistically significant differences were found between the tuberosity and pterygoid plate in terms of bone density. Based on the results of this study, an implant of at least 15mm long should be used in order to take advantage of the quantity and quality of the bone in this region.

Endoscopic transnasal approaches to pterygopalatine fossa tumors.

BACKGROUND: The pterygopalatine fossa (PPF) is a difficult area to access, as it has been traditionally treated by external approaches. The development of endoscopic transnasal approaches enables surgeons to reach this region through a minimally invasive route, reducing the associated morbidity. METHODS: We conducted a retrospective review of patients with benign and malignant tumors arising in or extending to the PPF, treated from 2000 to 2013 at a single institute, using endoscopic transnasal transmaxillary approaches. RESULTS: Thirty-seven consecutive patients with benign (27 cases) and malignant (10 cases) tumors were treated with curative intent. Radical resection was achieved in 36 of 37 patients. No major complications were observed. No local recurrences were observed, with a median follow-up of 38.5 months for malignancies and 60 months for benign tumors. CONCLUSION: The endoscopic transnasal approaches are safe and feasible techniques for the radical resection of selected tumors involving the PPF and should be tailored according to the biology and extension of the lesion. © 2015 Wiley Periodicals, Inc. Head Neck 38: E214-E220, 2016.