Radiological examination of greater palatine canal medial wall dehiscence.

INTRODUCTION: The greater palatine canal (GPC) connects the pterygopalatine fossa to the greater palatine foramen and houses vital neurovascular structures, which provide sensory innervation and circulation to the gums, palate, and nasal cavity. The GPC is of great clinical importance to various medical specialties; however, the anatomical variability of the GPC poses a risk of iatrogenic injury and complications. Therefore, understanding the normal anatomy and variations of the GPC is crucial for identifying vital structures and minimizing risks in clinical practice. PURPOSE: The aim was to fill a gap in the current literature by focusing on the prevalence of GPC medial wall dehiscence, a lesser-known anatomic variation, in radiological scans. METHODS: A total of 200 head and neck CT scans were examined, where 71 scans met the inclusion criteria. Statistical significance for incidence of GPC medial wall dehiscence, in reference to sex and side, was measured. RESULTS: The GPC medial wall dehiscence was observed in 69% of scans. Bilateral dehiscence was seen in 57.7% of scans, while right-sided and left-sided unilateral dehiscence were found in 14.1% and 11.3%, respectively. Significant difference was found between the incidence of bilateral dehiscence compared to the absence of dehiscence. CONCLUSION: Previous studies have highlighted the potential risks associated with invasive procedures involving the GPC. The clinical relevance of GPC medial wall dehiscence lies in the increased risk of transecting the contained neurovascular bundle. The presence of dehiscence emphasizes the need for meticulous preoperative radiologic analysis to tailor surgical approaches to individual patient anatomy.

Anatomy of the greater palatine foramen and canal and their clinical significance in relation to the greater palatine artery: a systematic review and meta-analysis.

PURPOSE: Accurate knowledge of greater palatine foramen (GPF) and greater palatine canal (GPC) anatomy is necessary to avoid injury to the greater palatine artery (GPA) when performing a variety of anesthesiologic, dental or surgical procedures. The aim of this paper was to perform a systematic review and meta-analysis of literature on the anatomy and localization of bony structures associated with the GPA, namely the GPF and GPC. METHODS: A systematic literature search was performed using PubMed, Embase, ScienceDirect, and Web of Science databases. Seventy-five studies were included in the meta-analysis (n = 22,202 subjects). RESULTS: The meta-analysis showed that the GPF is positioned 17.21 mm (95% CI = 16.34-18.09 mm) from the posterior nasal spine, 2.56 mm (95% CI = 1.90-3.22 mm) from the posterior border of the hard palate, 46.24 mm (95% CI = 44.30-48.18 mm) from the anterior nasal spine, 15.22 mm (95% CI = 15.00-15.43 mm) from the midline maxillary suture, 37.32 mm (95% CI = 36.19-38.45 mm) from the incisive foramen, and opposite the third maxillary molar (M3) in 64.9% (58.7-70.7%) of the total population. CONCLUSION: An up-to-date, comprehensive analysis of GPF and GPC clinical anatomy is presented. The results from this evidence-based anatomical study provides a unified set of data to aid clinicians in their practice.

Morphometric evaluation and clinical implications of the greater palatine foramen, greater palatine canal and pterygopalatine fossa on CBCT images and review of literature.

INTRODUCTION: The pterygopalatine fossa (PPF) infiltration is performed to reduce blood flow during endoscopic sinus surgery and septorhinoplasty, as well as to control posterior epistaxis and provide regional anesthesia in dental procedures. PPF infiltration performed with consideration of the morphometrics of greater palatine foramen (GPF), greater palatine canal (GPC) and PPF would increase the success of the procedure and reduce the risk of complications. The aim of this study is to investigate the GPF, GPC, lesser palatine foramen (LPF), lesser palatine canal (LPC) and PPF morphology via the images obtained by CBCT, to provide information for interventional procedures. MATERIALS AND METHODS: GPF, GPC, LPF, LPC and PPF were morphometrically evaluated retrospectively in CBCT images of 75 female and 75 male cases by Planmeca Romexis program. The 19 parameters were measured on these images. RESULTS: These parameters were evaluated statistically. The comparison of these parameters by genders revealed significant differences in distances between GPC-PC, PC-IOF, LPC-GPF, GPF-MS in the coronal and transverse planes, the distance between GPF and the occlusal plane of the teeth, GPF-PNS, GPF-IF and TD-GPF, and in the area of GPF. The number of LPF was found ranging from 1 to 5. CONCLUSION: Our results may help to insert to needle properly for application of maxillary nerve block with a high success rate and minimal complication. We recommend that the needle should be inserted 14-15 mm lateral to the midsagittal plane, 19-20 mm over the occlusal plane of the teeth and on the same line with the third molar teeth. For PPF infiltration through the GPF, the needle should be pushed forward 28 mm upward at 66° angle on the transverse plane and 14°-15° angle on the vertical plane.

Anatomical variations of the greater palatine canal in cone-beam computed tomography.

PURPOSE: To analyze anatomical variations of the greater palatine canal (GPC) using cone beam computed tomography (CBCT) images. METHODS: This study included 110 CBCTs. Axial slices were used to determine the shape of GPC and the number of lesser palatine foramina (LPF). Sagittal slices were used to assess the shape of the GPC and the number of lesser palatine canals (LPCs). RESULTS: The most prevalent axial and sagittal GPC shapes were oval (46.36%) and hourglass (23.64%). Most GPCs presented one LPF (47.27%) and one LPC (90.91%). CONCLUSIONS: GPC anatomy is highly variable. CBCT is a useful tool for evaluating the anatomical variations of GPC.

Morphometric study of the greater palatine canal: cone-beam computed tomography.

PURPOSE: To analyze greater palatine canal (GPC) dimensions using cone-beam computed tomography (CBCT) images, and to evaluate the position of the greater palatine foramen (GPF) with respect to various landmarks selected in relation to dental status. METHODS: This study included 150 CBCTs. Axial slices were used to determine the position and dimensions of the GPF. Sagittal slices were used to assess GPC length. Reference lines were established to evaluate the GPC diameter in sagittal and coronal slices. RESULTS: From the 77 GPF analyzed, 76 were located on level 2. Average posterior GPF distance was 6.59 ± 3.27 mm on right side and 7.35 ± 3.40 mm on left side. Several measurements to determine the position and dimensions of the GPF presented significant values (p ≤ 0.05). GPC length was 12.31 ± 1.96 mm on right side and 12.52 ± 2.15 mm on left side, statistically significant differences were detected between genders only on right canal (p ≤ 0.004). Sagittal and coronal reference lines presented significantly higher values for men except for the S3 (p < 0.062) and C1 (p < 0.067) in the left GPC. CONCLUSIONS: CBCT is a useful tool for evaluating GPC morphometrically in the three anatomical slices. The sagittal nasal plane and posterior nasal plane are two intraoral anatomical landmarks for the location of the GPF. Their scant variability allows accurate identification of GPFs in both dentate as well as edentulous patients.

[Imaging study of anatomical parameters related to pterygoid canal neurotomy].

Objective:Measuring the important anatomic parameters related to vidian neurectomy to locate the vidian nerve accurately and prevent the surgical complications. Methods:High resolution CT（HRCT） was used to measure the distance parameters between the important anatomic landmarks in 50 patients （100 sides） with chronic rhinosinusitis, sinus cyst or allergic rhinitis et al. The distance from the posterior opening of the palatovaginal canal to the upper edge of the sphenoidal process of palatine bone, the upper edge of the sphenoidal process of palatine bone to the external opening of the vidian canal, the external opening of the vidian canal to the greater palatine canal, and the external opening of the vidian canal to the foramen rotundus were measured. Results:The posterior opening of the palatovaginal canal, the upper edge of the sphenoidal process of palatine bone, the external opening of the vidian canal, the greater palatine canal, and the foramen rotundum are of great value in locating vidain nerve and preventing surgical complications. The distance from the posterior opening of the palatovaginal canal to the upper edge of the sphenoidal process of palatine bone, the upper edge of the sphenoidal process of palatine bone to the external opening of the vidian canal, the external opening of the vidian canal to the greater palatine canal, and the external opening of the vidian canal to the foramen rotundus were（12.46±1.19） mm, （3.23±0.36） mm, （6.09±0.75） mm and（7.6±1.16） mm respectively. Conclusion:HRCT can be used as a powerful tool for preoperative localization of the external pterygoid nerve orifice and its related important anatomical landmarks, and the preoperative distance parameters obtained are valuable for intraoperative localization of the pterygoid nerve to prevent the occurrence of complications.

Greater Palatine Canal: Computed Tomography-Based Anatomic Analysis And Clinical Significance for the Sinus and Skull Base Surgeon.

OBJECTIVE: Our aim is to describe the location and course of the greater palatine canal (GPC) by analyzing its relationship with anatomical landmarks that can be used during endoscopic sinus surgery. This information might help prevent injury to the neurovascular bundle. METHODS: A retrospective evaluation of paranasal sinus CT scans of 100 consecutive random patients, 200 sides, was performed. Five measurements related to the course of the GPC were conducted, from cranial to caudal. The anatomical landmarks were the inferior bony border of the sphenopalatine foramen to the cranial entrance of the GPC, the distance from the most dorsal, and inferior bony insertion of the middle turbinate and the inferior turbinate bones to the anterior margin of the GPC. The angle between the horizontal palatine bone and the GPC, its length, and the prevalence of osteophytes in GPC was also assessed. RESULTS: The mean distance of the inferior border of the sphenopalatine foramen to the cranial entrance of the GPC was 9.39 ± 1.72 mm. The mean distance of the dorsal insertion of the middle turbinate to the anterior margin of the GPC was 3.89 ± 0.93 mm. The distance of the dorsal insertion of the inferior turbinate to the anterior margin of the GPC was 3.16 ± 0.81 mm. The mean angle between the horizontal palatine bone and the GPC was 114.33 ± 10.92º and the mean length of the GPC was 30.23 ± 3.74 mm. None of the measurements showed a significant difference between the two sides. CONCLUSIONS: The landmarks used are easy to locate and assess on CT scans. These findings may help to make dissection safer in pathologies related to the pterygopalatine fossa, lateral sphenoid sinus or adjacent skull base.

Radioanatomic Study of the Greater Palatine Canal Relevant to Endoscopic Endonasal Surgical Landmarks.

Objective A radioanatomic study of surgically relevant variations in the greater palatine canal (GPC) on computed tomography (CT) was performed to determine susceptibility during endoscopic endonasal procedures. Study Design Blinded radioanatomic analysis. Setting Tertiary university hospital. Subjects and Methods Fifty consecutive paranasal CT scans (100 sides) were analyzed. Measurements were standardized to landmarks such as the inferior turbinate (IT) and floor of the nasal cavity (FNC) to assess variability and vulnerability of the nerve. Measurements included (1) incidence of maxillary sinus pneumatization posterior to the GPC, (2) distance from the posterior wall of the maxillary sinus to the GPC at the IT and FNC, (3) width of bone containing the GPC, (4) incidence of medial GPC dehiscence, and (5) angle of the GPC extending from the IT to FNC. Results Ninety-one percent of maxillary sinuses were pneumatized posterior to the GPC. The distance from the posterior wall of the maxillary sinus to the GPC was 2.8 ± 1.7 mm (range, -2.3 to 5.9) at the posterior attachment of the IT and 4.1 ± 3.1 mm (range, -6.3 to 11.9) at the FNC. The width of bone containing the GPC was 3.3 ± 1.3 mm (range, 1-8.9), and the medial bony GPC was dehiscent in 38% of cases. In the sagittal plane, the angle of the GPC between the IT and the FNC was 31.9 ± 6.9 degrees (range, 10.8-45). Conclusion The GPC has considerable anatomic variability relative to important surgical landmarks in endoscopic procedures. Preoperative review of CTs to assess vulnerability may prevent postoperative complications.

The Length of the Greater Palatine Canal in a Lebanese Population: a Radio-anatomical Study.

OBJECTIVE: The aim of this study was to evaluate the length of the greater palatine canal in a Lebanese population using cone-beam computed tomography (CBCT) technology. MATERIAL AND METHODS: In this study, we measured the length of 148 greater palatine canals in 74 CBCT images of Lebanese adult patients (38 females and 36 males). The data obtained was analyzed statistically to determine 1) if age is related to the length of the canal, 2) if the length of the left side tends to be systematically larger or smaller than the length of the right side, and 3) if the mean length of the canals in females is different than the one in males. RESULTS: In a sagittal plane, the average length of the greater palatine canal was 30.62 (30.64 mm on the right and 30.60 mm on the left). CONCLUSION: Within the limits of this study, we concluded that in our sample in a Lebanese population, the length of the greater palatine canal does not significantly vary according to age, gender, and side.

Radio-anatomical Study of the Greater Palatine Canal and the Pterygopalatine Fossa in a Lebanese Population: A Consideration for Maxillary Nerve Block.

AIM: The aim of this study was to describe the morphology of the component, greater palatine canal-pterygopalatine fossa (GPC-PPF), in a Lebanese population using cone-beam computed tomography (CBCT) technology. MATERIALS AND METHODS: CBCT images of 79 Lebanese adult patients (38 females and 41 males) were included in this study, and a total of 158 cases were evaluated bilaterally. The length and path of the GPCs-PPFs were determined, and the data obtained analyzed statistically. RESULTS: In the sagittal plane, of all the GPCs-PPFs assessed, the average length was 35.02 mm on the right and 35.01 mm on the left. The most common anatomic path consisted in the presence of a curvature resulting in an internal narrowing whose average diameter was 2.4 mm on the right and 2.45 mm on the left. The mean diameter of the upper opening was 5.85 mm on the right and 5.82 mm on the left. As for the lower opening corresponding to the greater palatine foramen, the right and left average diameters were 6.39 mm and 6.42 mm, respectively. CONCLUSION: Within the limits of this study, we concluded that throughout the Lebanese population, the GPC-PPF path is variable with a predominance of curved one (77.21% [122/158] in both the right and left sides); however, the GPC-PPF length does not significantly vary according to gender and side.

Maxillary nerve block via the greater palatine canal: An old technique revisited.

BACKGROUND: Maxillary nerve block through the greater palatine canal is rarely adopted by dental practitioners due to lack of experience in the technique at hand which may lead into several complications. Nevertheless, it is an excellent method to achieve profound anesthesia in the maxilla. This review focuses on the anatomy as well as the indications, contraindications, and complications associated with this technique. MATERIALS AND METHODS: A literature search was performed using the scientific databases (PubMed and Google Scholar) for articles published up to December 2014 in English, using the key words "maxillary nerve block via the greater palatine canal." A total of 34 references met the inclusion criteria for this review and were selected. CONCLUSION: Block of the maxillary nerve through the greater palatine canal is a useful technique providing profound anesthesia in the hemi-maxilla, if practiced properly.

Contribución al Estudio Descriptivo del Foramen y Canal Palatino Mayor / Contribution to the Descriptive Study of the Foramen and Greater Palatine Canal

RESUMEN: El foramen y canal palatino mayor (FPM y CPM) comunican boca con fosa pterigopalatina. El conocimiento adecuado de su morfología, permite el abordaje anestésico del nervio maxilar. En el vivo, el FPM está recubierto por una mucosa gruesa, debido a esto los puntos de referencia óseos y dentarios son importantes para ubicar el sitio de punción. Se ha descrito gran variabilidad en cuanto a la etnia, posición, forma, diámetros, longitudes y permeabilidad. Este estudio tuvo como objetivo describir éstas características en cráneos de adultos chilenos. Se utilizaron 31 cráneos de ambos sexos. En los paladares se determinó; forma, largo, profundidad y ancho. En los FPM se consideró su forma, diámetros y localización. En los CPM se registró su permeabilidad y su coincidencia con la forma del FPM. Los registros se realizaron con cámara digital, compás de precisión, caliper digital, compas tridimensional de Korkhaus y sonda metálica. Los resultados muestran un predominio de la forma cuadrada del paladar por sobre las formas triangular y redondeada. Las mediciones de su largo, ancho y profundidad indican diferencias por sexo y por etnia. La forma del FPM no muestra diferencia por sexo, primando la forma ovalada por sobre la fusiforme y la redondeada. La posición de este mismo foramen tampoco muestra diferencias sexuales, primando la posición frente al tercer molar superior, seguida por la posición frente al espacio entre segundo y tercer molar superior y por último frente al 2do molar superior. Las dimensiones del FPM son mayores en individuos masculinos. Los CPM se observaron en su totalidad permeables y los FPM no siempre coincidieron en forma con la sección transversal del CPM. Estos resultados y su comparación con la literatura indican variaciones importantes, lo que impide establecer directrices objetivas a la técnica anestésica que utiliza esta vía anatómica.

ABSTRACT: The greater palatine foramen and canal (GPF and GPC) communicate with the pterygopalatine fossa. The adequate knowledge of its morphology allows the anesthetic approach of the maxillary nerve. In vivo, the GPF is covered by a thick mucosa, therefore, the bone and dental reference points are important to locate the puncture site. Great variability has been described in terms of ethnicity, position, shape, diameters, lengths and permeability. The objective of this study was to describe these characteristics in skulls of Chilean adults. 31 skulls of both sexes were used. In the palates shape, length, depth and width were determined. In the GPF its shape, diameters and location were considered. In the GPC, their permeability and their coincidence with the shape of the GPF were recorded. The records were made with digital camera, precision compass, digital caliper, Korkhaus three-dimensional compass and metallic probe. The results show a predominance of the square shape of the palate over the triangular and rounded forms. The measurements of its length, width and depth indicate differences by sex and ethnicity. The shape of the GPF shows no difference by sex, with the oval shape prevailing over the fusiform and the rounded. The position of this same foramen also shows no sexual differences, with the position prevailing against the upper third molar, followed by the position in front of the space between the upper second and third molars and finally against the upper 2-molar. The dimensions of GPF are greater in male individuals. The GPC were found to be entirely permeable and the GPF did not always coincide in form with the cross section of the GPC. These results and their comparison with the literature indicate important variations, which prevents establishing objective guidelines for the anesthetic technique used in these cases.

Pterygopalatine fossa infiltration: A radio-anatomic study among adult patients in a tertiary private hospital

@#<p style="text-align: justify;"><strong>OBJECTIVE:</strong> As   a   guide   to   the   clinical   practice   of   infiltration   of   local   anesthesia   into   the pterygopalatine fossa via the greater palatine canal, this study sought to determine and record the  mean  CT  scan  measurements  of  the  following:  1)  palatal  mucosal  thickness,  2)  length  and width  of  greater  palatine  canal,  and  3)  length  and  width  of  pterygopalatine  fossa  among  adult patients in a private tertiary hospital in Quezon City.<br /><strong>METHODS:</strong><br /><strong>Design:</strong> Retrospective, Descriptive Study<br /><strong>Setting:</strong> Tertiary Private Hospital<br /><strong>Subjects:</strong> Paranasal Sinus (PNS) CT Scans of 113 adult patients from January 2014 to May 2014 were reviewed and evaluated. Excluded were images with pathology that distorted the anatomy of the sinuses and surrounding structures.<br /><strong>RESULTS:</strong> Our study showed average CT scan measurements of 5.98 mm palatal mucosal thickness, 16.99  mm  greater  palatine  canal  length,  18.75  mm  pterygopalatine  fossa  length,  2.37  mm greater palatine canal width and 2.58 mm pterygopalatine fossa width. Comparison of average measurements  by  sex  was  not  statistically  significant.  There  was  statistical  significance  when comparing the right palatal mucosal thickness of 5.86 mm with the left which was 6.11 mm with p-value of 0.001. Comparison between the length of the right pterygopalatine fossa of 18.48 mm with the  left side at 19.01 mm showed statistical significance with p-value of 0.01.<br /><strong>CONCLUSION:</strong> As the average measurement of the mucosal palatal thickness combined with the length of the greater palatine canal was 22.97 mm, we recommend bending the needle 23 mm from  the  tip  in  a  45  degree  angle  for  adult  patients  who  will  undergo  sinus surgery,  control  of posterior epistaxis, trigeminal nerve block and minor oral cavity surgeries.</p>