Pterygoid Process Research Articles

Sinus mucosal healing pattern according to pterygomaxillary disjunction type after Le Fort I osteotomy.

During Le Fort I osteotomy, the separation of the pterygomaxillary junction (PMJ) is a difficult procedure for most surgeons because it is invisible. In this process, damage to the posterior structures constituting the sinus or those adjacent to it, including the maxillary sinus posterior wall and pterygoid plate, may occur. We would like to investigate the effects of this on the inside of the maxillary sinus after surgery and whether there are complications. One-hundred patients who underwent Le Fort I osteotomy from 2013 to 2020 using cone-beam computed tomography images were classified into two groups (clean-cut type and fractured type) according to the PMJ cutting pattern. In addition, the mucosal thickness in the maxillary sinus was divided into preoperative, postoperative three months, one year, and the change over the course of surgery was evaluated retrospectively. Of the total 100 cases, the clean-cut type numbered 28 cases and the fractured type totaled 72 cases. Among the fracture types, part of the sinus wall and the pterygoid plate were broken in 69 cases, and the maxillary sinus posterior wall was detached in three cases. There was no statistically significant difference in sinus mucosal thickening between the clean-cut type and fractured type of the PMJ, three months and one year after surgery between the two groups. However, there was a significant difference in sinus mucosal thickness at postoperative one year in the case where a partial detachment of the maxillary sinus posterior wall occurred compared to not. Even if there is some damage to the structures behind the PMJ, it may not be reasonable to spend some time on the PMJ separation process considering the overall postoperative complications, if there is no significant difference inside the sinus, or increased probability of postoperative complications.

Effect of Bone-Borne Trans -Sutural Distraction Osteogenesis Therapy on the Cranial Base of Children With Midfacial Hypoplasia Due to Cleft Lip and Palate.

Bone-borne trans -sutural distraction osteogenesis (TSDO) is widely used to treat midfacial hypoplasia in children with cleft lip and palate; however, its effects on the cranial base are still poorly understood. The authors aimed to study morphological changes in the cranial base after TSDO. Pre and postoperative computed tomography (CT) images of cleft lip and palate children with midfacial skeleton dysplasia who underwent TSDO were collected retrospectively, and their corresponding 3-dimensional models were measured. Results showed no significant change in the length of the anterior or posterior cranial fossa, but the length of the middle cranial fossa increased significantly. The anterior cranial base rotated upward with the sella turcica at the center, whereas the cranial base angle increased. The sphenoid bone exhibited morphological changes. Post-TSDO, the lateral plate of the pterygoid process increased in length. The angle of the 2 lateral plates of the pterygoid process, the greater wings of the sphenoid bone, and the smaller wings of the sphenoid bone decreased. Posterior inclination of the pterygoid process increased. Mean volume of the sphenoidal sinus increased postoperatively compared with the preoperative volume. Apparent changes in the cranial base after TSDO are primarily in the middle cranial fossa, manifesting as an increase in the sphenoid bone body length, expansion of the sphenoidal sinus volume, growth of the pterygoid process forward and downward, a decrease in the angle of both the greater and smaller wings of the sphenoid bone, and an increase in the posterior inclination of the pterygoid process.

Medial deviation of the pterygoid hamulus as an uncommon cause of persistent oral and facial pain – a rare case report and literature review

ABSTRACT Background Pterygoid hamulus syndrome, a painful oral and facial syndrome, has been described in literature to be correlated with morphological changes in the length of the pterygoid hamulus of the sphenoid bone. Clinical Presentation The current case report describes the treatment for severe, continuous pain in the posterior right palate. Despite numerous conservative treatments given to the patient, no improvement was seen. Cone beam computed tomography (CBCT) measurements revealed an elongation as well as a significant medial deviation of the lower extremity of the medial pterygoid plate. The surgical resection was performed under local anesthesia. The pain subsided two days after the surgery, and there were no relapses in the weeks that followed. Conclusion The medial deviation of the hamulus appeared to be important in the etiology of this painful syndrome. Additional research based on CBCT measurements will be required.

Mutations in the TBX15-ADAMTS2 pathway associate with a novel soft palate dysplasia.

We reported de novo variants in specific exons of the TBX15 and ADAMTS2 genes in a hitherto undescribed class of patients with unique craniofacial developmental defects. The nine unrelated patients represent unilateral soft palate hypoplasia, lost part of the sphenoid bone in the pterygoid process, but the uvula developed completely. Interestingly, these clinical features are contrary to the palate's anterior-posterior (A-P) developmental direction. Based on developmental characteristics, we suggested that these cases correspond to a novel craniofacial birth defect different from cleft palate, and we named it soft palate dysplasia (SPD). However, little is known about the molecular mechanism of the ADAMTS2 and TBX15 genes in the regulation of soft palate development. Phylogenetic analysis showed that the sequences around these de novo mutation sites are conserved between species. Through cellular co-transfections and chromatin immunoprecipitation assays, we demonstrate that TBX15 binds to the promoter regions of the ADAMTS2 gene and activates the promoter activity. Furthermore, we show that TBX15 and ADAMTS2 are colocalization in the posterior palatal mesenchymal cells during soft palate development in E13.5 mice embryos. Based on these data, we propose that the disruption of the TBX15-ADAMTS2 signaling pathway during embryogenesis leads to a novel SPD.

P03.04.B Garcin syndrome and hippocampal-sparing WBRT: successful resolution of a rare case

Abstract Background first case of a rare Garcin syndrome resolution in a young metastatic breast cancer(BC) patient treated with a hippocampal-sparing approach. Material and Methods we report a case of a 49-year-old caucasian female. The medical record review was relevant for BC diagnoses in 1997, when she was 26yo; complicated by bone and liver metastasis appeared in 2008. In March 2020, she was referred to our department complaining about increasingly worsening left otalgia with initial hearing loss, left facial numbness, and homolateral decreased facial sensitivity, left increased lacrimation, and tingling tongue. Clinical presentation was suggestive for a Guillain-Alajouanine-Garcin Syndrome (Garcin Syndrome), caused by a lytic lesion in the left sphenoid wing. A contrast MRI (02/04/2020) of the brain demonstrated a lytic lesions in the left sphenoid wing, that was noted to infiltrate surrounding bone of the sphenoid sinus wall, including clivus, left pterygoid process and petrous bone; two parietal and occipital bone lesions were identified with a partial leptomeningeal involvement. According to the good PS, she underwent to a hippocampal-sparing WBRT VMAT plus a sequential boost on sphenoid lesion. PTV and OARs were delineated according to a fused planning MRI/CT image. Bilateral hippocampal contours were generated on the set according to RTOG 0933 contouring atlas. After that, a hippocampal avoidance(HA) region was created by expanding the hippocampal contours by 5 mm in all directions according to Brown et al.The PTV-HA was defined as the WB parenchyma, meninges and skull, excluding the HA-region, dose prescription 30Gy/10fx; the PTV-Boost was defined as the sphenoidal metastases, dose prescription of sequential boost was 12Gy/4fx. VMAT was used to deliver the conformal RT plan. Planning priorities that should be followed were:Hippocampus, OpticChiasm, OpticNerve_L or OpticNerve_R, Lens_L or Lens_R. Results The neurological symptoms improved after the end of RT with a complete resolution two months later. At the last MRI, a year and a half from the end of RT, there was no evidence of brain lesion, and no neurological symptoms were referred. These are our results of plan sum: for PTV-HA D2%=43.43 Gy, D98%=26.36 Gy, V30=94.96%; for Hippocampus D100%=8.78 Gy, Dmax=17.24 Gy; for Left OpticNerve Dmax=33.51%; for Right OpticNerve Dmax=29.25%; for OpticChiasm Dmax=35.93%. Conclusion To our knowledge, this is the first described case using the VMAT technique to spare the hippocampus plus a boost in a rare case of Garcin Syndrome. Prevention of neurocognitive sequelae by hippocampal avoidance has shown promise in several studies as in this case. Sequential boost demonstrated to be feasible and effective.Advanced RT techniques may be used to customize a treatment that allows preserving cognitive impairment achieving good clinical results in the long-term survival of metastatic patients.

Radiological anatomy of foramen rotundum and its surgical implications

IntroductionThe use of endoscopic sinus surgery in the field of otorhinolaryngology is due to many reasons such as better visualization, the complex anatomy of the skull base and the relations between vital vascular and nervous elements, the crucial preoperative knowledge about the detailed anatomy of the area, and the computed tomography that is a useful tool for them to plan the safest route of surgery. The foramen rotundum (FR) is the inherent bony structure in the skull base located in the greater wing of the sphenoid bone on the floor of the middle cranial fossa, located adjacent to the nasopharynx, and often invaded by nasopharyngeal cancer and other malignant brain tumors. The This study aims to give a detailed description of anatomical variations of FR, as well as its relationships with the surrounding vital structures, to instruct a preoperative planning for endoscopic surgery.MethodsThe distances between the foramen rotundum and fixed anatomical landmarks like the nasal floor and pterygoid process were measured in 200 foramen rotunda of 100 patients older than 18 years old and without known skull base pathology. The patients included in this study were demonstrated and evaluated separately using a multislice computed tomography (CT) technique with DICOM viewing software (Osirix or Horos).ResultsThe average horizontal distance between the FR and vidian canal (VC) on each side, vertical distance between FR and VC on each side, direct distance between the FR and VC on each side, FR diameter, rotundum angles, FRs and nasal floor angles, and FR and optic nerve distances calculated has no significant difference. The P values were 0.471, 0.521, 0.072, 0.283, 0.952, 0.661, and 0.663, respectively. The gender comparison in the present study showed no significant distances on both the right and left sides. The P values 0.765, 0.879, 0.621, 0.297, 0.992, and 0.227 were direct, horizontal, and direct distances, respectively.ConclusionsThis study provides more light on the anatomy of the foramen rotundum with the other anatomical/surgical key structures used in endonasal surgeries such as the lateral pterygoid plate and vidian canal.

Pattern of pterygomaxillary disarticulation associated with Le Fort I maxillary osteotomy

Pterygomaxillary disarticulation (PMD) contributes to surgical complications of Le Fort 1 osteotomy and is associated with undesirable fractures of the pterygoid plates. The aim of this paper was to investigate the patterns of PMD in Le Fort I osteotomies using Rowe's disimpaction forceps, and to evaluate correlations with age and anatomical measurements. Cone-beam computed tomography (CBCT) scans of 70 consecutive orthognathic patients were retrospectively evaluated to study four patterns of PMD: Type 1 - PMD at, or anterior to, the pterygomaxillary junction (PMJ); Type 2 - PMD posterior to the PMJ; Type 3 - PMJ separation with comminuted fracture of the pterygoid plates; Type 4 - disarticulation of the maxilla involving the pterygoid plates above the level of the osteotomy line. The preoperative anteroposterior and mediolateral thicknesses of the PMJ and the length of the medial and lateral pterygoid plates were assessed. Satisfactory PMD was achieved in all cases and no severe complications were reported, including vascular, dental, mucosal, or neural damage. The most common PMD was Type 1 (54.3%), followed by Type 2 (40%). Comminuted fracture of the pterygoid plates was limited to 5.7% of cases, and no Type 4 was detected. A weak correlation was detected between PMJ thickness and PMD pattern (p = 0.04). No statistically significant correlation was detected between patients’ age and type of PMD. PMD of Le Fort I maxillary osteotomy using a Smith spreader and Rowe's disimpaction forceps proved safe, with minimal damage to the pterygoid plates.

CBCT Analysis of Dento-Skeletal Changes after Rapid versus Slow Maxillary Expansion on Deciduous Teeth: A Randomized Clinical Trial.

The aim of the present study was to compare skeletal and dental changes after rapid maxillary expansion (RME) and slow maxillary expansion (SME) performed by a Leaf Expander (LE) with upper deciduous teeth as anchorage and using 3D CBCT (Cone Beam Computed Tomography) analysis. Mixed dentition patients were randomly divided in two groups, according to the different expansion used anchored on maxillary primary second molars: the RME group (n = 16) was treated with a Hyrax type expander, whereas the SME group (n = 16) was treated with an LE expander. CBCT scans were performed before (T1) and after treatment (T2) and analyzed with a custom landmarks system. A paired t-test was used for intragroup analysis between T1 and T2, and a Student t-test was used for intergroup analysis; statistical significance was set at 0.05. Both RME and SME groups showed a statistically significant increase in dental and skeletal diameters. Group comparisons between T1 and T2 showed a significant expansion rate in the RME group for upper permanent molars (p = 0.025) but not for deciduous molars (p = 0.790). Moreover, RME showed higher increases for skeletal expansion evaluated at nasal walls (p = 0.041), whereas at pterygoid plates did not show any significant differences compared with the SME group (p = 0.849). A significant transverse expansion could be achieved with the expander anchored on deciduous teeth. RME and SME produced effective both skeletal and dentoalveolar transverse expansion; RME produced more anterior expansion than SME but less control regarding the permanent molar decompensation. SME by LE therefore could be an efficient and helpful alternative in the treatment of transverse maxillary deficiency in growing patients.

FRACTURE OF MAXILLARY, PALATINE, AND SPHENOID BONE IN ATTEMPT OF TOOTH 18 EXTRACTION: CASE REPORT

A 40-year-old male patient reported to the trauma service of a hospital with pain, difficulty opening his mouth, and facial edema after attempting extraction of tooth 18 approximately 1 week ago. The cone beam tomographic examination showed “bone fractures, with fragment displacement, in the maxillary tuber involving the palatal bone, pterygoid hamulus and lateral lamina of the pteroid process of the sphenoid bone. Tooth 18 is extruded and moved to the palate next to the bone fragment of the tuber, palate, and pterygoid process of the sphenoid. This condition promotes discontinuity of the cortical bone of the floor and posterior wall of the maxillary sinus, of the floor and lateral wall of the nasal fossa, with bucco-sinusal and bucco-nasal communication.” The surgery was performed in a surgical center with general anesthesia and nasotracheal intubation, involving repositioning of the fracture and fixation with wire, plate, and screws. The extraction will be performed later. A 40-year-old male patient reported to the trauma service of a hospital with pain, difficulty opening his mouth, and facial edema after attempting extraction of tooth 18 approximately 1 week ago. The cone beam tomographic examination showed “bone fractures, with fragment displacement, in the maxillary tuber involving the palatal bone, pterygoid hamulus and lateral lamina of the pteroid process of the sphenoid bone. Tooth 18 is extruded and moved to the palate next to the bone fragment of the tuber, palate, and pterygoid process of the sphenoid. This condition promotes discontinuity of the cortical bone of the floor and posterior wall of the maxillary sinus, of the floor and lateral wall of the nasal fossa, with bucco-sinusal and bucco-nasal communication.” The surgery was performed in a surgical center with general anesthesia and nasotracheal intubation, involving repositioning of the fracture and fixation with wire, plate, and screws. The extraction will be performed later.

A vidian neurectomy approach with the sphenoid process of the palatine bone as a landmark

Objective:To explore a safe and effective surgical approach to locate and cut the vidian nerves with the sphenoid process of the palatine bone as a landmark. Methods: The landmarks of locating the external opening of the vidian canal were confirmed by the dissection of the cadaveric heads, and the feasibility of locating the vidian nerves with the determined landmarks was verified during operation. Results:The anatomical landmarks, which are the anterior opening of palatovaginal canal, the posterior opening of palatovaginal canal, palatovaginal canal and the nasal pharyngeal crest of the root of the pterygoid process can be used as the important landmarks of locating vidian nerve. In the cases of 10 patients with refractory allergic rhinitis and vasomotor rhinitis, the vidian nerves were successfully located and sectioned, and one patient was complicated with short-term unilateral palatal numbness after surgery. Conclusion:The anterior opening of palatovaginal canal, the posterior opening of palatovaginal canal, palatovaginal canal and the nasal pharyngeal crest of the root of the pterygoid process can be used as surgical markers for vidian neurectomy with the sphenoid process of the palatine bone as landmarks.

Asymptomatic Massive Fibrous Dysplasia Obliterating Maxillary Sinus Extending to the Skull Base: a Case Report and Review of Literature

Fibrous dysplasia is a rare bone condition in which normal bone is replaced by aberrant fibrous tissue. The patient may come to evaluate with other diseases and while doing investigations, it is observed. Here we present a case of 24 years male with fibrous dysplasia who came to our OPD with swelling around the left cheek region for 5 days. The patient underwent a Computerised tomography scan which revealed an expansile, sclerotic, cystic ground-glass appearance that extended to the maxillo-alveolar ridge, right sphenoid sinus wall, right pterygoid plate, and zygomaticofacial suture. The right maxillary sinus was almost obliterated. These radiographical features of the lesion were indicative of fibrous dysplasia in the maxilla.

Assessment of low-dose paranasal sinus CT imaging using a new deep learning image reconstruction technique in children compared to adaptive statistical iterative reconstruction V (ASiR-V)

PurposeTo compare the effects of deep learning image reconstruction (DLIR) and adaptive statistical iterative reconstruction V (ASiR-V) on image quality in low-dose computed tomography (CT) of paranasal sinuses in children.MethodsLow-dose CT scans of the paranasal sinuses in 25 pediatric patients were retrospectively evaluated. The raw data were reconstructed with three levels of DLIR (high, H; medium, M; and low, L), filtered back projection (FBP), and ASiR-V (30% and 50%). Image noise was measured in both soft tissue and bone windows, and the signal-to-noise ratios (SNRs) and contrast-to-noise ratios (CNRs) of the images were calculated. Subjective image quality at the ethmoid sinus and nasal cavity levels of the six groups of reconstructed images was assessed by two doctors using a five-point Likert scale in a double-blind manner.ResultsThe patients’ mean dose-length product and effective dose were 36.65 ± 2.44 mGy·cm and 0.17 ± 0.03 mSv, respectively. (1) Objective evaluation: 1. Soft tissue window: The difference among groups in each parameter was significant (P < 0.05). Pairwise comparisons showed that the H group’ s parameters were significantly better (P < 0.05) than those of the 50% post-ASiR-V group. 2. Bone window: No significant between-group differences were found in the noise of the petrous portion of the temporal bone or its SNR or in the noise of the pterygoid processes of the sphenoids or their SNRs (P > 0.05). Significant differences were observed in the background noise and CNR (P < 0.05). As the DLIR intensity increased, image noise decreased and the CNR improved. The H group exhibited the best image quality. (2) Subjective evaluation: Scores for images of the ethmoid sinuses were not significantly different among groups (P > 0.05). Scores for images of the nasal cavity were significantly different among groups (P < 0.05) and were ranked in descending order as follows: H, M, L, 50% post-ASiR-V, 30% post-ASiR-V, and FBP.ConclusionDLIR was superior to FBP and post-ASiR-V in low-dose CT scans of pediatric paranasal sinuses. At high intensity (H), DLIR provided the best reconstruction effects.

Oral Mucosal Melanoma: A Case Report and Literature Review

Oral mucosal melanoma is an unusual and aggressive malignant tumor that mainly affects the palate of men aged between 50 and 60 years. We present a literature review focusing on the etiopathogenesis and the clinicopathologic features of this entity. In addition, we reported a rare case of an oral mucosal melanoma arising in the left cheek of a 60-yea r- old man. Computed tomography scan revealed infiltration of the tumor to other anatomic structures including the maxillary sinus, the zygomatic bone and the pterygoid processes. Based on its extension, the lesion was considered inoperable and treatment with three-dimensional conformal radiation therapy was proposed but the patient only attended to the first session and died from cancer progression 6 months after the diagnosis. This paper reinforces the importance of inclusion of this malignant tumor in the differential diagnosis of pigmented lesions of the oral mucosa.

Value of skull base invasion subclassification in nasopharyngeal carcinoma: implication for prognostic stratification and use of induction chemotherapy

ObjectivesPrognoses for nasopharyngeal carcinoma (NPC) between categories T2 and T3 in the Eighth American Joint Committee on Cancer (AJCC) staging system were overlapped. We explored the value of skull base invasion (SBI) subclassification in prognostic stratification and use of induction chemotherapy (IC) to optimize T2/T3 categorization for NPC patients.MethodsWe retrospectively reviewed 1752 NPC patients from two hospitals. Eight skull base bone structures were evaluated. Survival differences were compared between slight SBI (T3 patients with pterygoid process and/or base of the sphenoid bone invasion only) and severe SBI (T3 patients with other SBIs) with or without IC using random matched-pair analysis. We calculated the prognosis and Harrel concordance index (C-index) for the revised T category and compared IC outcomes for the revised tumor stages.ResultsCompared to severe SBI, slight SBI showed better 5-year overall survival (OS) (81.5% vs. 92.3%, p = 0.001) and progression-free survival (PFS) (71.5% vs. 83.0%, p = 0.002). Additional IC therapy did not significantly improve OS and PFS in slight SBI. The proposed T category separated OS, PFS, and locoregional recurrence-free survival in T2 and T3 categories with statistical significance. An improved C-index for OS prediction was observed in the proposed T category with combined confounding factors, compared to the AJCC T staging system (0.725 vs. 0.713, p = 0.046). The survival benefits of IC were more obvious in the advanced stage.ConclusionsNPC patients with slight SBI were recommended to downstage to T2 category. The adjustment for T category enabled better prognostic stratification and guidance for IC use.Key Points• For nasopharyngeal carcinoma (NPC) patients in T3 category, slight skull base invasion was a significant positive predictor for OS and PFS.• NPC patients with slight SBI might not gain significant survival benefits from induction chemotherapy.• Downstaging slight SBI NPC patients to T2 category would make a more accurate risk stratification, improve the predicting performance in OS, and have a better guidance in the use of IC for patients in advanced stage.

The anatomy of the foramina and efferent nerve fibers from the pterygopalatine ganglion in posterolateral nasal wall.

BackgroundThe advance of endoscopic surgery has enabled selective section of the postganglionic nerve branches from pterygopalatine ganglion (PPG) as a modification of the vidian neurectomy. Recent microanatomic studies have suggested that the nasal mucosa is also innervated by multiple efferent rami associated with the sphenopalatine artery (SPA) in the procedure “posterior nasal neurectomy.” This anatomic cadaveric study aims to identify all postganglionic nerve fibers in the lateral nasal wall which should inform future surgical procedures aimed at interrupting these nerve fibers.MethodsTwo cadaver heads, with a total of three individual sides, were dissected. All neurovascular structures penetrating the vertical plate of palatine bone were carefully identified following meticulous removal of the overlying mucosa layers. The efferent nerve fibers were identified and dissected back to their origin—the PPG or greater palatine nerve.ResultsSeveral foramina with efferent PPG nerves were identified on the vertical plate of the palatine bone and medial pterygoid plate. The superior, middle, and inferior turbinates (IT) were innervated by efferent nerves from the PPG via the anterior region of the SPA. The IT was innervated from nerves originating from behind the SPA through bony foramina. The lateral wall of inferior meatus was innervated by efferent nerves that originated from greater palatine nerve and pharyngeal nerve.ConclusionThis study demonstrated the anatomical positions of the postganglionic nerves that innervate the lateral nasal wall. These nerves are located anterior to the SPA as well as posterior to the SPA, where they penetrate the palatine bone.Level of evidence: NA.

Three-dimensional finite element analysis of the effect of alveolar cleft bone graft on the maxillofacial biomechanical stabilities of unilateral complete cleft lip and palate

BackgroundThe objective is to clarify the effect of alveolar cleft bone graft on maxillofacial biomechanical stabilities, the key areas when bone grafting and in which should be supplemented with bone graft once bone resorption occurred in UCCLP (unilateral complete cleft lip and palate).MethodsMaxillofacial CAD (computer aided design) models of non-bone graft and full maxilla cleft, full alveolar cleft bone graft, bone graft in other sites of the alveolar cleft were acquired by processing the UCCLP maxillofacial CT data in three-dimensional modeling software. The maxillofacial bone EQV (equivalent) stresses and bone suture EQV strains under occlusal states were obtained in the finite element analysis software.ResultsUnder corresponding occlusal states, the EQV stresses of maxilla, pterygoid process of sphenoid bone on the corresponding side and anterior alveolar arch on the non-cleft side were higher than other maxillofacial bones, the EQV strains of nasomaxillary, zygomaticomaxillary and pterygomaxillary suture on the corresponding side were higher than other maxillofacial bone sutures. The mean EQV strains of nasal raphe, the maximum EQV stresses of posterior alveolar arch on the non-cleft side, the mean and maximum EQV strains of nasomaxillary suture on the non-cleft side in full alveolar cleft bone graft model were all significantly lower than those in non-bone graft model. The mean EQV stresses of bilateral anterior alveolar arches, the maximum EQV stresses of maxilla and its alveolar arch on the cleft side in the model with bone graft in lower 1/3 of the alveolar cleft were significantly higher than those in full alveolar cleft bone graft model.ConclusionsFor UCCLP, bilateral maxillae, pterygoid processes of sphenoid bones and bilateral nasomaxillary, zygomaticomaxillary, pterygomaxillary sutures, anterior alveolar arch on the non-cleft side are the main occlusal load-bearing structures before and after alveolar cleft bone graft. Alveolar cleft bone graft mainly affects biomechanical stabilities of nasal raphe and posterior alveolar arch, nasomaxillary suture on the non-cleft side. The areas near nasal floor and in the middle of the alveolar cleft are the key sites when bone grafting, and should be supplemented with bone graft when the bone resorbed in these areas.

Frontal sinus pneumatization: An isolated finding or a sign of concomitant anatomical variation?

To determine the association between frontal sinus pneumatisation and concomitant anatomical variations in paranasal sinuses as seen on computed tomography. A total of 403 patients who underwent paranasal sinus computed tomography were allocated to three groups according to the degree of frontal sinus pneumatisation (type 1 - hypoplasia; type 2 - medium size; and type 3 - hyperplasia). In this unique model, the prevalence of ipsilateral variations on paranasal sinuses on each side of the head were analysed separately within each pneumatisation group. The type 3 frontal sinus pneumatisation group showed a greater association with ipsilateral variations of the sphenoid bone. Variations included pneumatisation of the anterior clinoid process, lateral sphenoid recess, pterygoid process and greater wing, and exposure of Vidian canal. This group also showed significant associations with male gender, and the presence of frontal and Onodi cells. Interpretation of the paranasal sinus variations is imperative for pre-operative evaluation in functional endoscopic sinus surgery, particularly in patients with frontal sinus hyperplasia. Attention to variation on the ipsilateral side is informative.

Cranial Dysmorphology in the Palatine, Vomer, and Pterygoid Plates of Fgfr2mice

The fibroblast growth factor and receptor system (FGF/FGFR) regulates cell proliferation and differentiation for various tissue types in the body – including osseous tissue. Mutations in the FGFR2 gene are associated with craniosynostosis, leading to alterations of the shape of bones in the head and face. We have previously demonstrated premature fusion of the spheno‐septal synchondrosis in Fgfr2C342Y/+ mice, a model for Crouzon syndrome. Here, we further describe the specific morphology of individual bones as a result of the Fgfr2C342Y/+ mutation.We used microCT scans of mutant and wild‐type littermates at two developmental stages (adult and postnatal day 14) to create 3D virtual reconstructions of the skull in the program 3DSlicer. After transforming each scan to a uniform, orthogonal orientation, we collected coordinate data for 38 fixed craniometric landmarks to estimate the shape of the cranium. We used the geomorphpackage in R to perform a Procrustes superimposition and principal components analysis (PCA). We used the resulting shape coordinates in a two‐way Procrustes ANOVA to test the effects of Age and Genotype. In addition, we isolated key cranial elements (palatine, vomer, and pterygoid plates of the sphenoid) to compare between genotype groups at the P14 stage using a mesh‐to‐mesh comparison. This allowed us to test our expectation that fusion of the spheno‐septal synchondrosis has a greater impact on the vomer than on the palatines or pterygoid plates.Our morphometric analysis and two‐way Procrustes ANOVA confirmed previous reports of statistically significant cranial shape differences between wild‐type and Fgfr2 mutants at both timepoints. Vomer shape was significantly altered in the mutant P14 cranium when compared to other key cranial elements (palatine, and sphenoidal pterygoid plates), suggesting that fusion of the spheno‐septal synchondrosis has a greater impact on the vomer compared to the other bones in the skull. Our mesh‐to‐mesh comparison showed that the vomer is both dorso‐ventrally and rostro‐caudally compressed in mutants relative to wild‐type mice at this early stage. Additionally, the palato‐sphenoid suture appears prematurely fused in the mutants.This study provides insight into the skeletal phenotypic mechanisms that characterize diseases involving mutations of the FGFR2 gene, such as Crouzon syndrome. The dysmorphology of individual bones affect other osseous structures due to morphological integration within the skull. Elucidating the underlying mechanisms of the phenotypic expression of FGFR2 syndromes supports further translational research.

Surgical approach of transnasal endoscopic resection of benign lesions in the paramedian lateral skull base

Objective:To investigate the surgical approach of transnasal endoscopic resection of benign lesions in the paramedian lateral skull base. Methods:Retrospectively analyze 40 cases of the clinical data of patients with benign lesions of the skull base from August 2018 to February 2021 with transnasal endoscopic surgery, including 9 cases of cholesteatoma, 6 cases of hemangioma, 1 case of hemangiopericytoma, 6 cases of schwannoma, 15 cases of sphenoid sinus lateral crypt meningocele and cerebrospinal fluid leak, 3 cases of nasopharyngeal carcinoma bone inflammation after radiotherapy. All patients underwent transnasal endoscopic surgery, and different surgical approaches were selected according to the lesion location. Results:The total resection rate was 100% in 40 patients. One patient had cerebrospinal fluid rhinorrhea, which was cured after repair. During the follow-up period of 3-30 months, 39 patients had different degrees of numbness in the maxillary or mandibular region, and the numbness disappeared from 2 weeks to 6 months; one patient with schwannoma still had numbness on one side of the upper lip one year after surgery. Conclusion:Transnasal endoscopic resection of benign lesions in the paramedian skull base has a high surgical safety and cure rate. The surgical approach selection mainly focuses on the pterygoid process and extends to the periphery. The shortest and least damaging approach should be selected according to the lesion location, and the endoscopic approach should also be selected according to the surgeon's expertise.

Unilateral isolated fracture of the pterygoid plate: a case report

Pterygoid plate fractures are often associated with Le Fort fractures and accompanied by other facial fractures such as frontal sinus and naso-orbital-ethmoid fractures; isolated pterygoid plate fractures are extremely rare.&#x0D; Le Fort fractures must be surgically treated with fixation of unstable fracture segments to re-establish bone form and function, and the pterygoid process must be surgically stabilized; however, surgical treatment is unnecessary in isolated pterygoid plate fractures.&#x0D; Here, we report a rare case of isolated unilateral fracture of the pterygoid process in a 71-year-old female patient who had a syncopal episode with secondary head injury and a hematoma at the base of the right orbit.&#x0D; A computed tomography scan showed unilateral right pterygoid plate fracture with signs of emphysema in the ipsilateral masticatory space. The patient also had a fracture of the medial wall of the right maxillary sinus with hemosine, but no fractures of the skull base or theca. She was treated conservatively.