The Incisive Canal: A Comprehensive Review

Assessment of the Nasopalatine Canal Length and Shape Using Cone-Beam Computed Tomography: A Retrospective Morphometric Study

The anatomical position of the nasopalatine canal in the anterior maxilla makes it one of the most important vital structures in the region. Surgical and implant procedures in this area require local anesthesia to be administered. It is, therefore, important to morphologically assess the length and shape of the nasopalatine canal for performing surgical procedures with more accuracy in this area. Cone-Beam Computed tomography scans were scrutinized using inclusion criteria of age 18 years and above, absence of any pathological lesions/fracture/surgery in the nasopalatine area, absence of orthodontic treatment or maxillary jaw correction surgeries, and exclusion criteria including CBCT scans with artifacts or error s in the area of interest, anterior implants, absence of bone diseases, trauma, surgeries, and impactions in the area of interest. A total of 360 scans were analyzed for the length and shape of the nasopalatine canals. The results of the study showed that the mean nasopalatine canal length was 12.51 mm. The hourglass shape of the canal was most common and had the highest representation in both genders, with male 80.62% and female 87.01%. A statistically significant difference (p < 0.001) was noted in nasopalatine canal length between males and females. The study provides insight into the significant association of gender with the canal's shape and length of the canal. The length of the canal does not influence with age. These parameters are helpful for surgical planning and interventions in the anterior maxillary region.

Quantitative assessment of cleft volume and evaluation of cleft's impact on adjacent anatomical structures using CBCT imaging

OBJECTIVES

To determine pre-operative cleft volume and evaluate cleft´s impact on surrounding anatomical structures in children and adolescents with orofacial clefts using cone bean computed tomography (CBCT) imaging.

METHODS

The present retrospective study retrieved CBCT examinations of 68 patients from a previous study. The examinations had been exposed either before (n = 53) or after (n = 15) alveolar bone grafting. Pre-operative volume of cleft was determined, and type and location were evaluated. Morphological changes on the adjacent anatomical structures, including the incisive foramen, the nasal septum and floor, and the inferior turbinate, were assessed.

RESULTS

Mean bilateral cleft volume was 0.76 cm3, while mean unilateral cleft volume was 1.08 cm3; the difference was significant (p < 0.001). Variation in cleft volume, however, was large. The incisive foramen was not visible in the majority of cases with bilateral clefts (71%); the difference was significant (p = 0.001). In cases with unilateral clefts, the nasal septum in 87% was curved towards the cleft or graft side. Also, the mean size of the widest part of the inferior turbinate was 8.8 mm on the cleft or graft side and 10.4 mm on the non-cleft side. The difference was significant (p < 0.001).

CONCLUSIONS

When required, CBCT is a feasible method for quantitatively illustrating alveolar clefts and their impact on the morphological development of surrounding structures. Variation in cleft volume was large.

A Rare Case of Schwannoma of the Right Greater Palatine Nerve in a 17-Year-Old Female Patient

Schwannomas are not uncommon in the maxillofacial region; however, those with intraoral localization and, in particular, the hard palate are among the least frequently described. In the current case report, we present a 17-year-old girl with a histologically verified schwannoma of the hard palate on the right, originating from the right greater palatine nerve. In her case, despite the lysis of the palatine bone from the tumor compression, the disease is asymptomatic, causing only a weak sensation of local discomfort. The lesion was removed surgically under general anesthesia and the resulting defect of the palatal mucosa was compensated by plastic reconstruction with a lingual mucosal flap on a posterior feeding base. The recovery period was uneventful.

Nasopalatine Duct Cyst with Impacted Inverted Mesiodens: A Rare Case Report and Literature Review

Nasopalatine duct cyst (NPDC) is a non-odontogenic, developmental epithelial cyst that accounts for 1% of maxillary cysts. It often arises due to the spontaneous proliferation of the epithelial tissue remnants, although trauma, bacterial infection, and mucous retention may also trigger the proliferation. Owing to its slow-growing, asymptomatic nature, the cyst is often discovered as an accidental finding during routine clinical and radiographic examinations. However, the majority of cases present as a tiny, asymptomatic swelling just posterior to the palatine papillae. Radiographically, it appears as a well-defined oval or round radiolucency in the maxillary anterior teeth region and should be differentially diagnosed with inflammatory periapical lesions and a wide incisive foramen. A pulp vitality test is essential to rule out lesions of endodontic origin. Microscopically, NPDCs display a mixed pattern of the epithelial lining and exhibit neurovascular bundles (small to medium-sized nerves, arteries, and veins), and minor salivary glands in the cystic connective tissue, a distinctive feature facilitating a confirmatory diagnosis. Enucleation and marsupialization remain the treatment of choice. NPDC associated with impacted mesiodens is an extremely uncommon entity. A comprehensive literature search carried out on the PubMed and Google Scholar search engines revealed only three cases of NPDC with impacted mesiodens to date. The purpose of this study is to report an extremely rare case of NPDC associated with an impacted inverted mesiodens in a 19-year-old male patient who presented with an asymptomatic swelling in the maxillary anterior teeth region. To the best of our knowledge, this is only the fourth reported case of NPDC with impacted mesiodens.

The Role of Morphometric Characteristics of Anterior Maxilla in Planning the Interventions Accompanied by Orthodontic Teeth Movement – An Overview

The anterior maxilla or premaxilla is part of the upper jaw and the most significant content of this region, from the aspect of orthodontic therapy, are the incisor teeth. The frequency of complications during orthodontic movement of the upper incisors refers to a more detailed evaluation of the anatomical structures of the premaxilla. The aim of this study was to investigate morphological and morphometric characteristics of the anterior maxilla by cone beam computed tomography, which could be of interest for planning orthodontic teeth movement. By reviewing the available literature, we compared the values of the alveolar bone height, the distance between the alveolar crest and enamel – cement boundary, total alveolar bone width, the thickness of the buccal, and palatal plate, nasopalatine canal, and accessory canals of the anterior maxilla. The results of our study show changes in the labial and palatal aspects of the alveolar bone height during orthodontic interventions. Different results of the alveolar bone width are in correlation with gender, age, and type of orthodontic tooth movement. Distance between the nasopalatine canal and maxillary central incisors was estimated at the value from 4 to 6 mm, which is below the recommended value for maximum incisal retraction by Proffit. Research results show variations in shape, length, and diameter of the nasopalatine canal, which indicates individual varieties detected on cone beam computed tomography. Other anatomical structures and measures show an insignificant correlation with orthodontic teeth movement. According to the contradictory results of the available articles, it is required to achieve an individual approach to orthodontic interventions in the area of the anterior maxilla.

The Shape of Nasopalatine Canal as a Determining Factor in Therapeutic Approach for Orthodontic Teeth Movement-A CBCT Study

The aim of this study was to evaluate the impact of the nasopalatine canal (NPC) shape and its morphometric characteristics on expected teeth movement by assessing the distance to maxillary central incisors (MCIs) according to NPC type. The retrospective study was performed on 133 CBCT images. The following parameters were obtained: the antero-posterior diameter (A-P) of the nasal foramen (NF), canal length, A-P and mediolateral diameter (M-L) of the incisive foramen (IF), and the distance between NPC and MCIs. With the exception of being hourglass-shaped, each NPC shape showed specific impacts of NPC shape on the relationship between NPC diameters at different sections and distances to MCIs. In banana-shaped NPC, a significant correlation was observed for A-P NF diameter, while in cylindrical-shaped NPC, a significant correlation was observed for NPC length. The increase in M-L IF, A-P IF, A-P NF, and NPC length in funnel-shaped NPC may be a risk factor for interventions that could result in teeth movement. According to the results, it seems that the proposed methodological approach for analysis of CBCT slices in the anterior maxilla may offer detailed information that could be an additional tool in planning the procedures that result in expected teeth movement.

Nasopalatine duct cyst with sebaceous differentiation: a rare case report with literature review

BACKGROUND

The aim of this study was to report a rare case of nasopalatine duct cyst with sebaceous differentiation. Further, a systematic search of the literature was performed to identify studies reporting patients with intraosseous jaw cysts with sebaceous differentiation.

CASE PRESENTATION

A 55-year-old Korean man was referred to our hospital because of a cystic lesion of the anterior maxilla. Radiologic examination revealed a well-circumscribed radiolucent lesion in the anterior maxilla. Histology showed a respiratory columnar and cuboidal epithelium-lined cyst. Transition from the ciliated columnar epithelium to stratified squamous epithelium with sebaceous differentiation was observed. Based on these findings, the final diagnosis was nasopalatine duct cyst with sebaceous differentiation. A systematic search of the literature was performed to identify studies reporting patients with intraosseous jaw cysts with sebaceous differentiation. There were 24 cases of sebaceous differentiation in the epithelium of the cysts including 2 odontogenic keratocysts, 8 orthokeratinized odontogenic cysts, 8 dentigerous cysts, 1 radicular cyst, and 2 glandular odontogenic cysts. However, no case reports describing the occurrence of nasopalatine duct cysts with sebaceous differentiation have been reported.

CONCLUSION

This first case report of nasopalatine duct cysts with sebaceous differentiation could provide insight into the diagnostic process of cystic lesions with sebaceous differentiation.

[Clinical study of age-related sensory innervation of the anterior hard palate]

OBJECTIVES

The present study aimed to explore the innervation of the anterior hard palatine and its relationship with individual development stage. Specifically, the effects of anesthesia on patients of different ages were observed, and neurodevelopment in the maxillofacial region was invesitgated. References that are helpful in selecting local anesthesia were provided.

METHODS

A total of 182 patients with mixed dentition were randomly divided into the nasopalatine nerve block and greater palatine nerve block groups. Then, 219 patients with permanent dentition were divided into an adolescent group (13-18 years old) and adult group (over 19 years old), all of whom underwent bilateral greater palatine nerve block. Palatal mucosal pain sensation was tested pre- and post-anesthesia with Von Frey hairs.

RESULTS

Among the children with mixed dentition, bilateral greater palatine nerve block tended to result in better anesthetic effects than nasopalatine nerve block (P<0.05), except in the incisive papilla. No difference in anesthetic effect was observed between adolescents and adults (P>0.05). The bilateral greater palatine nerve block was more effective in inducing an anesthestic effect in the anterior hard palatine in mixed dentition than in permanent dentition (over 13 years old; P<0.05).

CONCLUSIONS

The sensation of the anterior hard palatine seems mainly dominated by the greater palatine nerve until mixed dentition and gradually shifted to the nasopalatine nerve in conjunction with maxillary development and tooth replacement. Hence, the innervation of the anterior hard palatine induce a secondary development during the development of the maxilla.

Septoplasties are unlikely to cause postoperative numbness of the anterior palate

BACKGROUND

Septoplasties and septorhinoplasties are very commonly performed surgical procedures in modern aesthetic and functional medicine. Throughout the surgery, close manipulation to the incisive nerves' course is being executed. This retrospective analysis followed up on potential sensitivity disorders of the anterior palate due to nerve damage.

METHODS

This retrospective review of 2000 patients' charts, who had undergone the procedure of a septoplasty or septorhinoplasty between June 2013 and January 2019 was conducted at the Department of General Otorhinolaryngology, Medical University of Graz. Medical records of all included patients were reviewed with special attention to postoperative numbness of the anterior palate.

RESULTS

Among the 2000 included patients, a septoplasty was performed in 48% (n = 955), a septorhinoplasty in 35% (n = 703) and a septoplasty in combination with a functional endoscopic sinus surgery in 17% (n = 342). In total, 86% (n = 1721) showed no complications at all during the follow-up period. In 0.25% (n = 5) a sensitivity disorder of the anterior palate occurred. Of the five cases with a postoperative numbness of the anterior palate four occurred after a septoplasty and the fifth occurred following a septorhinoplasty.

CONCLUSION

At this current time, this is the largest study investigating postoperative numbness of the anterior palate retracing septoplasty or septorhinoplasty. As a result, the currently used techniques for the operations do not pose a risk for the incisive nerve despite close surgical manipulation to the nerves' course. Nevertheless, patients should be informed and educated about the possibility of an occurring sensitivity disorder regarding the anterior palate during informed consent.

Morphometric analysis of nasopalatine foramen in Sri Lankan population using CBCT

Nasopalatine canal (NPC) is an important anatomical structure present in the anterior mid maxilla. It has the synonyms of incisive canal or anterior palatine canal. The objective of this study was to identify the morphometric characteristics of the NPC in group of Sri Lankan people using Cone beam computer tomography (CBCT) and to determine normal morphological course and anatomical variations. Fifty Maxillary CBCT images of anterior maxilla, obtained from the archives of the University Dental Hospital, Peradeniya were retrospectively analyzed to determine the position of the NPC. Morphology, canal dimension of NPC and its relation to the maxilla. Majority had a single opening (48%) or 2 openings (46%). Average diameter of the canal was 3.692 mm with a range of 2-6 mm. Majority of the canals had funnel shape and were vertically curved. Average length of canal was 12.142 mm and angulations of the curvature was 115.694⁰. Average antero-posterior diameter at nasal fossa was 2.852 mm, at mid-palate 2.366 mm and at hard palate 3.034 mm. Our findings were different from the findings reported in the literature. This may be due to the differences in ethnicity or limited size of sample. Within the limits of this study, we conclude that the form of the NPC is variable; predominantly funnel shaped with a single or two openings and with an average diameter of 3.7 mm in Sri Lankan population. Identification of variations in the position and shape will help in clinical practice specially in introducing local anesthetic block injections during dental treatment.