Augmentation in Proximity to the Incisive Foramen to Allow Placement of Endosseous Implants: A Case Series

Implant treatment after traumatic tooth loss: A systematic review

BACKGROUND/AIMS

Treatment after traumatic tooth loss is challenging and is currently guided by expert opinion and the individual patient situation. The aim of this study was to provide an overview on the outcome of dental implant treatment in the anterior maxilla after traumatic tooth loss, based on a systematic review of the existing evidence.

MATERIALS AND METHODS

A systematic search of the literature was performed on PubMed, Cochran Library and Web of Science following the PRISMA guidelines based on a structured research question (PICO). All clinical studies of five patients or more with follow-up of at least 1 year after implant loading were included. Patients were at least 18 years of age. Cohen's Kappa-coefficient was calculated. The Newcastle-Ottawa Scale was applied to assess the quality of the included studies. Descriptive statistical methods were applied.

RESULTS

Nine hundred and ninety-nine articles were identified through the systematic search. Finally, six articles were eligible for inclusion. The studies comprised prospective and retrospective cohort studies and case series. From these, 96 patients with 120 implants were included. The age ranged from 18 to 59 years. The survival rates of implants and superstructures were 97% and 95%, respectively, after a mean follow-up of 3.5 years. Mean marginal bone resorption was 0.56 mm (range 0.21-1.30 mm). Complication rates were 7% and 11% on implant and superstructure level, respectively. Patient-reported outcome measures and objective evaluations showed a high level of satisfaction with the aesthetic outcome. Bone augmentation was performed in 60 implant sites. Three patients underwent pre-surgical orthodontic treatment. The maxillary central incisor was the most frequently replaced tooth (70%).

CONCLUSIONS

This systematic review revealed a low level of evidence on the outcome of dental implant treatment after traumatic tooth loss. Systematic reporting of treatment outcomes of tooth replacements after dental trauma is highly encouraged to further guide dentists for the benefit of these challenging patients.

Clinical and anatomical study of foramen locations in jaw bones and adjacent structures

This study aims to find and locate foramens exactly in maxilla and mandible in case of complications during surgeries.Computer topographic angiography (CTA) images of 120 cases were reviewed. The measurements were performed on coronal, sagittal and axial planes after the 3 dimension volume reconstruction. The distances among foramens, bony landmarks, teeth, and facial artery were all measured with the angles as adjustments.The incisive foramen (IF) was measured 20.55 ± 2.81 mm to margo inferior of incisor, and 45.27 ± 5.27 degree from the axial midline. The greater palatine foramen located 43.17 ± 2.55 mm from the IF, while 21.08 ± 3.75 degree from the midline in axial plane. The lesser palatine foramina located 44.56 ± 5.74 mm from the IF and 20.05 ± 3.59 degree to the midline. The Mandibular foramen (MBF) was 91.15 ± 1.86 mm horizontally to the margo inferior of incisor. The angle that the MBF-margo inferior of incisor line made with the axial midline was 31.25 ± 2.89 degree. The shortest horizontal distance from the mental foramen (MF) to the facial artery in sagittal plane was 21.90 ± 1.86 mm, while it became 13.00 ± 2.05 mm in coronary section. The horizontal distance from the MF to the margo inferior of incisor in sagittal plane was 22.04 ± 3.22 mm. It turned out to be 25.78 ± 5.23 mm between MF and mid-sagittal line in coronary section. The vertical distance was 25.20 ± 3.06 mm from the upper margin of the second premolar to the MF.The foramens were clearly seen through CTA. Moreover, linear and angular measurements were presented, which makes it safer and wiser for surgeons to consider the biometric data before operations.

The nasopalatine canal, a limiting factor for temporary anchorage devices: a cone beam computed tomography data study

Objectives

There is only little knowledge on topographical predispositions of the nasopalatine canal as a limiting factor for insertion of mid-palatal temporary anchorage devices (TAD). The purpose of the study was to assess the course of the nasopalatine canal, the adjacent vertical bone quantity, and whether it might differ among vertical facial types, using pre-existing cone beam computed tomography (CBCT) scans.

Material and Methods

Out of a consecutive sample collected from April 2008 to August 2012, only patient data depicting both upper and lower jaw completely were evaluated retrospectively. The linear measurements were taken on the respective midsagittal view perpendicular to the palate at the level of 1st molar/2nd premolar (5/6), 2nd premolar/1st premolar (4/5), and 1st premolar/canine (3/4). Screen-prints were used to measure the inclination of the nasopalatine canal in relation to the maxillary jaw base. Maxillary and mandibular divergence was assessed on rendered lateral cephalograms.

Results

Out of 3869 pre-existing consecutive CBCT scans, data from 398 patients met the inclusion criteria and could be extracted. The mean vertical bone was 4.09 mm at the 5/6 level, 5.22 mm at the 4/5 level, and 3.14 mm at the 3/4 level, respectively. A statistically significant negative correlation exists between jaw divergence and the canal angulation with regard to the maxillary base. A statistically significant negative correlation exists between the canal angulation and vertical bone measurements at the 4/5 and 3/4 levels.

Conclusions

Vertical bone volume is sufficient at 4/5 level for TAD placement, and bares only a small risk for neuro-sensory impairment. Therefore, only in rare cases a CBCT is justified for palatal implant placement. The course of the nasopalatine canal is negatively correlated with the vertical skeletal facial pattern pointing to the fact that in hypodivergent patients a TAD might be placed in a more distal or paramedian region.

Alteraciones anatómicas del conducto nasopalatino en pacientes dentados y desdentados en el sector anterosuperior utilizando tomografía computarizada de haz cónico

Introducción: el conducto nasopalatino (CNP) es un trayecto intraóseo largo y delgado presente en la línea media anterior del maxilar, conecta el paladar con el piso de la cavidad nasal. El objetivo del estudio fue comparar las medidas del conducto nasopalatino y su forma mediante tomografía de haz cónico en pacientes dentados y pacientes desdentados en el sector anterosuperior. Materiales y métodos: estudio descriptivo y comparativo, se tomaron del archivo del Departamento de Imagenología 150 tomografías de pacientes dentados anterosuperiores y 52 tomografías de pacientes desdentados anterosuperiores. Mediante Excel y su herramienta “aleatoria” se seleccionaron 30 tomografías de pacientes dentados y 30 tomografías de pacientes desdentados. Se midió en el plano sagital oblicuo la distancia anteroposterior del conducto nasopalatino a nivel de su tercio superior, medio e inferior. Para determinar su altura se tomó el plano axial del nivel de la bifurcación superior hasta la desembocadura palatina. La adquisición de imágenes se realizó través del software i-Dixel del equipo 3D Accuitomo 170 MORITA, sistema DICOM. Resultados: los pacientes dentados presentan alturas mayores en relación a los pacientes edéntulos. En diámetro transversal los pacientes edéntulos presentan mayor tamaño a nivel del canal del CNP. Las medidas a nivel inferior, medio y superior en las corticales del diámetro del CNP en pacientes dentados son menores en relación a los pacientes edéntulos. Conclusión: los pacientes de 40 a 70 años de ambos sexos con edentulismo anterosuperior presentaron variaciones estructurales topográficas que consisten en mayor anchura, menor longitud y mayor dimensión transversal, siendo conductos agrandados.

The Incisive Canal: A Comprehensive Review

The incisive canal, also known as the nasopalatine canal, is an interosseous conduit through the anterior maxilla connecting the oral and nasal cavities. Within this canal lies the nasopalatine nerve and the vascular anastomosis between the greater palatine and sphenopalatine arteries. The embryology of the canal has led to interesting theories explaining its function. Efforts have been made to describe the morphometrics of the incisive canal by radiologic evaluation across sex and ethnicities. This paper aims to review the current literature on the embryology, anatomy, and clinical relevance of the incisive canal.

Implant Anchorage in the Nasopalatine Canal for the Rehabilitation of Severely Atrophic Maxilla

PURPOSE

This study aimed to describe the clinical case of implant placement in the nasopalatine canal as an aid for atrophic maxilla rehabilitation.

CASE REPORT

The surgical procedure was carried out in 2 stages, the first part consisted of a surgery to lift the maxillary sinus membrane associated with the xenogeneic bone placement and the second part consisted of the surgery for the implants placement, both under local anesthesia. A number of seven osseointegrated implants were placed in the maxilla, one was anchored in the nasopalatine canal region after having its neurovascular content emptied by means of the use of drill threads of the implant system. After 5 months, the implant reopening was carried out, followed by the molding, manufacturing and placement of the protocol-type prosthesis. The case has a 4-year follow-up without any painful symptomatology.

CONCLUSION

The implant placed in the nasopalatine canal region is a viable option to assist in the rehabilitation with implant-supported prostheses in atrophic maxilla.

Implants placed in the nasopalatine canal to rehabilitate severely atrophic maxillae: a retrospective study with long follow-up

To assess the survival rate of implants placed in the nasopalatine canal for the rehabilitation of patients with atrophic maxillae and the level of satisfaction of these patients. A retrospective study was performed between 2000 and 2009 of patients with severe atrophy of edentulous maxillae (Cawood and Howell's class V) rehabilitated with implant-supported prostheses with 1 implant placed in the nasopalatine canal. A preoperative computed tomography scan was obtained of all patients and all surgeries were performed by the same surgeon. The following parameters were assessed: neurosensory status of the anterior palate (using the pointed/blunt discrimination method); implant success rate according to criteria described by Albrektsson et al; patient satisfaction with the prosthetic treatment (using visual analogue scales). Thirteen patients with a mean age of 54.8 years were treated, 5 men and 8 women. Seventy-eight implants were placed: 13 in the nasopalatine canal, 6 in the zygomatic bone, 12 in the pterygomaxillary region, 2 in the frontomaxillary buttress and 45 in other locations. Six patients reported a slight decrease in sensitivity in the anterior palate after surgery, which disappeared in all cases within a few weeks. Two early failures (before prosthetic loading) and no late failures (after prosthetic loading) of nasopalatine implants were recorded, yielding a success rate for these implants of 84.6% after a mean follow-up of 70 months (range 24 to 132 months. High patient satisfaction with the prosthetic restoration was generally achieved in terms of comfort, stability, function, esthetics, and ease of cleaning. Residual bone is associated with the nasopalatine canal, even in patients with severe maxillary atrophy. This canal may be considered a possible location for an anterior implant when rehabilitating atrophic patients using implant-supported prostheses.

Observation of maxillary incisive canal using dry skulls between Hellman's dental age IA and IIIC

The maxillary incisive canals were observed in childhood from infancy to school-aged children to clarify their development. Cone-beam computed tomography was performed to investigate 44 dry child skulls. Two-dimensional images of various planes in the maxillary incisive canal were reconstructed on a computer using 3-dimensional visualization and measurement software. Then, antero-posterior angulation, and antero-posterior and lateral axes of the maxillary incisive canal were measured at the inferior and middle levels. The mean difference of angulation between the inferior and middle levels was 2.3 degrees in IIC, and 11.1 degrees in IIIC. The mean ratio of the lateral axis to antero-posterior axis at the middle level was 2.54 in IIC, and 1.93 in IIIC. In conclusion, it was antero-posteriorly straight from IA to IIC, and, after IIIA, it curved at the middle level. The cross-sectional shape in IIC was depressed with a larger lateral axis.

Anatomy and morphology of the nasopalatine canal using cone-beam computed tomography

Purpose

This study was performed to evaluate the general anatomy and morphology of the nasopalatine canal using cone-beam computed tomography (CBCT) and to determine the human anatomic variability of the nasopalatine canal in relation to age and gender.

Materials and Methods

The study included 100 subjects aged between 20 and 86 years who were divided into the following 3 groups: 1) 20-34 years old; 2) 35-49 years old; 3) ≥50 years old. The subjects were equally distributed between the genders. CBCT was performed using a standard exposure and patient positioning protocol. The data of the CBCT images were sliced in three dimensions. Image planes on the three axes (X, Y, and Z) were sequentially analyzed for the location, morphology and dimensions of the nasopalatine canal by two independent observers. The correlation of age and gender with all the variables was evaluated.

Results

The present study did not reveal statistically significant differences in the number of openings at the nasal fossa; diameter of the nasal fossa openings; diameter of the incisive fossa; shape, curvature, and angulation of the canal as viewed in the sagittal sections; antero-posterior dimensions and length of the canal in the sagittal sections; or the level of division of the canal in the coronal plane by age. However, males and females showed significant differences in the length of the canal in the sagittal sections and level of the division of the canal in the coronal plane.

Conclusion

The present study highlighted important variability observed in the anatomy and morphology of the nasopalatine canal.