Clinical anatomy of the superior alveolar nerves

Cone-beam computed tomography of accessory canals of the canalis sinuosus and analysis of the related risk factors

PURPOSE

Cone-beam computed tomography (CBCT) was used in this study for evaluating the diameter, prevalence, spatial location, and risk factors of the accessory canal (AC) of the canalis sinuosus.

METHODS

A comprehensive assessment of the incidence rate, diameter, three-dimensional (3D) spatial location, and direction of travel of AC was performed on 1003 CBCT images. The CBCT data were used to reconstruct a 3D model of the maxilla to determine the alveolar bone volume. The obtained data were further analyzed and processed.

RESULTS

AC was present in 50.1% of images. Male patients more frequently had ACs than female patients did (P < 0.01) and was positively correlated with the maxillary alveolar bone volume (P < 0.001, OR 1.532). Age or nasopalatine canal diameter were not significantly associated with the occurrence of AC (P > 0.05). Among the 502 patients with AC, AC was present on the left side, right side, and bilaterally in 189, 98, and 215, respectively. The maximum number of ACs observed per individual was eight. The average AC diameter was 0.89 ± 0.26 mm (minimum, 0.5 mm; maximum, 2.02 mm).

CONCLUSIONS

As the prevalence of AC and its trajectory display considerable variation among individuals, surgeons must consider the possibility of the presence of AC when devising surgical plans involving the anterior maxillary region.

Edema and hematoma after local anesthesia via posterior superior alveolar nerve block: a case report

Although rare, complications can occur with anesthetic procedures. The posterior superior alveolar nerve (PSAN) block anesthetic technique has a high success rate, but positive aspiration can cause bruising, transient diplopia, blurred vision, and temporary blindness in approximately 3% cases. When edema occurs, it is occasionally massive, especially in the infratemporal fossa, and the resulting hematoma is usually unsightly. A 20-year-old woman presented with massive edema followed by hematoma in the upper right jaw immediately after PSAN block administration, which subsequently spread to the oral mucosa. The patient did not report any complications during the anesthetic procedure. However, after the injection was administered, the patient experienced anesthetic sensations, which rapidly evolved to facial edema. There was mild pain, but without intraoral or extraoral bleeding. The patient was prescribed medicines and instructed to perform contrast therapy. Although hematomas and edema are rare, they are difficult to prevent. The choice of local anesthetic and appropriate application of the anesthetic technique can minimize their occurrence.

Morphological and Morphometric Characteristics of Anterior Maxilla Accessory Canals and Relationship with Nasopalatine Canal Type-A CBCT Study

This study aimed to evaluate principal morphological and morphometric characteristics of accessory canals (ACs) of the anterior maxilla, as well as to analyze the relationship with nasopalatine canal (NPC) type. The results of our study showed that ACs were observed in almost 50% of participants. They were mostly presented bilaterally and in a curved shape, with a palatal foramen position. The morphometric characteristics of ACs were significantly influenced by NPC type. NPC type had the strongest impact on the distance between the NPC and AC, as well as on the distance between the AC and the facial aspect of buccal bone wall, in inferior parts of the alveolar ridge. On the other hand, the distance between the AC and central incisors was not significantly influenced by NPC shape in the lower region of the anterior maxilla. However, the participants with the banana-type of the NPC expressed the reduction in distance from the AC to the central incisor at the upper part in comparison with the subjects with the cylindrical-type of the NPC. On the basis of the results of this study, the simultaneous estimation of ACs and the NPC seems reasonable, as this approach may be useful in the prevention of complications which could occur during implant surgery interventions.

[Surgical anatomy of the maxillary sinus]

BACKGROUND

Improved understanding of the microanatomy of the paranasal sinuses, including its individual variations, makes a substantial contribution to current progress in endonasal endoscopic microsurgery. Microanatomy of the sinuses is an active field of present scientific investitations.

MATERIALS AND METHODS

A comprehensive review on microanatomy of the maxillary sinus is presented from the perspective of contemporary endonasal endoscopic microsurgery.

RESULTS

The range of variation of the individual microanatomy of all sections of the maxillary sinus is presented, in particular to minimize secondary sugical tissue trauma, to avoid complications (e.g. on orbital tissues) and as a basis for the prelacrimal access to the maxillary sinus.

CONCLUSION

Improved understanding of the range of microanatomical variations reduced the burden on the patient while opimizing the effectiveness of the necessary surgical manipulations.

Assesment of accessory branches of canalis sinuosus on CBCT images

Background

The aim of this study is to describe the presence, to reveal the frequency and characteristics of accessory canals (ACs) of the canalis sinuosus (CS) by cone beam computed tomography (CBCT).

Material and Methods

A total of 326 CBCT examinations were scanned retrospectively. The anatomical views were evaluated on sagittal, axial, coronal and cross sectional imaging. The following parameters were recorded: age, sex, presence or absence of ACs, location in relation to the adjacent teeth and distance to the nasal cavity floor (NCF), alveolar ridge crest (ARC) and buccal cortical bone (BCB), and incisive canal. All the collected data were statistically analyzed.

Results

113 patients (34,7%); presented ACs in total 214 foramina of the sample. There were no statistically significant changes in the presence of ACs regarding age groups excluding 80-89 years. But there is a statistically significant difference regarding the frequency of ACs and the gender. The prevalence for male patients was higher than female patients. Curved-shape configuration of CS prevalence is found as 69,15%. The prevalence of vertical tracing is 26,16% and Y-shape configuration of CS prevalence is 4,67%. Diameter of the foramens of the CS branches was 1.30 mm. The mean distance of the AC to the NCF, BCB, and ARC were found 13,83 mm, 6,60 mm and 5,32 mm, respectively.

Conclusions

In the anterior palatal region, ACs are mostly related to CS’s branches. So; knowing the course of CS branches in surgical planning and radiographic evaluations in this region is extremely important for preventing complications and avoiding misdiagnosis.

Key words:Anterior superior alveolar nerve, canalis sinuosus, maxilla.

Cranial nerve V2 and Vidian nerve trauma secondary to lateral pterygoid recess encephalocele repair

BACKGROUND

The incidence of adverse sequelae related to trauma of cranial nerve V₂ (V2) and the Vidian nerve (VN) during endoscopic pterygoid recess repair (PRR) of lateral sphenoid encephalocele is insufficiently reported in the medical literature. As part of our quality assessment and improvement program we sought to analyze the incidence and severity of V2 and VN injury during a 9-year experience (2010-2018) with PRR.

METHODS

Hypoesthesia, paresthesia, and dry eye and their impact on patient quality of life were sought through chart review and a self-reported 0 to 5 Likert scale for each symptom.

RESULTS

Thirty-five patients underwent repair of spontaneous cerebrospinal-fluid (CSF) rhinorrhea, with 11 consecutive patients undergoing endoscopic PRR. Mean follow-up for PRR was 32.5 months (range, 2.4 to 103.3 months). Although definitive management resulted in 100% success, 1 required secondary treatment. Eight patients were available for long-term follow-up (72.7%) and completed a symptom severity questionnaire using a Likert-scale. All patients observed either hypoesthesia, paresthesia, or dry eye of varying gradation (scale, 0 to 5). None described disabling symptoms, and some reported gradual improvement. Numbness, paresthesia, and dry eye were reported by 6 of 8 (75%), 5 of 8 (62.5%), and 4 of 8 (50%) patients, respectively. The mean Likert score among the 8 patients who completed this questionnaire noticing hypoesthesia, paresthesia, and dry eye was 2.6, 1.3, and 1.8, respectively.

CONCLUSION

Meticulous surgical technique is paramount for successful PRR and minimizing nerve injury, yet the anatomic variation of the lateral pterygoid recess can be challenging, and neural injury is a real risk. Preoperatively, patients should be counseled that although V2 or VN injury is common, most patients describe resulting symptoms to be rarely bothersome.

Anesthetic Efficacy of Intranasal 3% Tetracaine plus 0.05% Oxymetazoline (Kovanaze) in Maxillary Teeth

INTRODUCTION

Needle-free anesthetic delivery is a promising alternative to traditional anesthetic routes of administration. The purpose of this study was to determine the patient preference for and pulpal anesthetic efficacy of a 3% tetracaine plus 0.05% oxymetazoline (Kovanaze) nasal spray in maxillary lateral incisors and first premolars.

METHODS

Fifty adult subjects randomly received a 3% tetracaine plus 0.05% oxymetazoline (Kovanaze) nasal spray and mock infiltration or a mock nasal spray and 2% lidocaine with 1:100,000 epinephrine infiltration at the maxillary lateral incisor or first premolar in 2 appointments spaced at least 1 week apart in a single-blind cross-over design. Pulpal anesthesia was evaluated with an electric pulp tester. Side effects and subject preferences were also recorded.

RESULTS

Anesthetic success was significantly lower for the Kovanaze nasal spray and mock infiltration (22%-37%) than for the mock nasal spray and lidocaine infiltration (89%-91%). Subjects reported more unwanted effects (nasal drainage and congestion, burning, pressure, and sinus congestion) after the Kovanaze nasal spray and mock infiltration than the mock spray and maxillary infiltration. Before participating in the study, more subjects (56%) preferred the nasal spray route versus a standard infiltration (44%). After experiencing both routes of administration, 100% of subjects preferred the standard infiltration.

CONCLUSIONS

The 3% tetracaine plus 0.05% oxymetazoline (Kovanaze) nasal spray provided significantly less successful pulpal anesthesia than the lidocaine infiltration, was less preferable, and caused more unwanted effects.

Efficacy of intraligamentary anesthesia in maxillary first molar extraction

INTRODUCTION

Infiltration anesthesia (IA) is the method to anaesthetize maxillary teeth successfully. In contrast, intraligamentary anesthesia (ILA) has been used as supplementary anesthesia during tooth extraction, particularly when regional block anesthesia has failed. In this study, we compare the efficacy of and patient satisfaction with ILA vs IA when extracting maxillary first molar teeth.

METHODS

Forty patients were enrolled in this study and 80 maxillary first molars extracted. All patients served as their own control, with ILA as the experimental side and IA as the control side. The two techniques were compared for efficacy using a visual analog scale (VAS) and patient satisfaction compared using a verbal rating scale (VRS).

RESULTS

The mean VAS pain score for extraction using ILA was lower than that for IA (20.30±3.18 and 13.93±1.95 mm, respectively; P<0.001). For injection pain, the mean VAS pain score in the ILA side was higher than the IA side (42.28±4.51 and 31.73±3.1 mm, respectively; P<0.001). VRS results showed a higher number of patients who felt that pain during ILA was greater than expected compared with IA.

CONCLUSION

IA appears less painful during injection compared with ILA, and provides sufficient pain relief during extraction. However, ILA can be used when IA fails to achieve the desired pain suppression, as it provides higher extraction-pain relief.

The Incidence of Complications after Canine Fossa Puncture Performed during Endoscopic Sinus Surgery

Background

Patients with extensive disease affecting the maxillary sinus may require a canine fossa approach for complete removal of disease. This study was designed to determine the complications associated with this procedure.

Methods

We performed a retrospective study of 21 patients who had undergone a canine fossa puncture at an academic hospital complex in Adelaide, Australia.

Results

A total of 37 canine fossa punctures were made in 21 patients. Twenty-eight of the 37 (75.7%) sides in which a canine fossa puncture was performed experienced a complication. The most common complaint was of cheek swelling in 14 (38%) followed by facial pain in 12 (32%), facial numbness in 11 (30%), cheek pain in 10 (27%), dental numbness in 10 (27%), gingival complications in 9 (24%), and facial tingling in 6 (16%) of sides. Most complications (75.5%) resolved within the 1st month after surgery. Six patients (28.6%) had persistent complications with facial tingling in 3 patients (50%) followed by facial numbness and tingling in 1 patient (11%), facial numbness alone in 1 patient (8.3%), and facial pain in 1 patient (7.1%).

Conclusion

Canine fossa antrostomy is a technique that provides additional access to the maxillary sinus. Surgeons need to be aware that, although minor, a significant number of patients will experience both transient and long-term complications.

Cone-beam tomographic analysis of canalis sinuosus accessory intraosseous canals in the maxilla

The aim of this study was to assess the frequency, location and width of accessory canals (AC) of canalis sinuosus (CS) using cone beam computed tomography and compare our findings with recent literature. Additionally, intraosseous canals (IOC) in the sinus wall other than the CS were noted. A retrospective analysis of 219 scans from our university department was conducted. The registered parameters were age, sex, location and width of canals. Group A consisted of 201 (85 males and 116 females) adults ranged from 19 to 99 years of age (mean age = 47.5 years). A total of 136 patients (67.6%) presented at least 1 AC, of which 55 cases showed a foramen width greater than 1 mm (27.4%). Group B had a sample size of 18 adolescents (7 males and 11 females) with a range of age from 7 to 18 years (mean age = 15.8 years). Eight cases (44.4%) presented at least one AC, of which only 3 had a foramen width greater than 1 mm (3.6%). ACs were found to occur predominantly at central incisors region (Group A) and the left lateral incisor and canine as well as the central incisors regions (Group B). Adolescents showed a lower prevalence of accessory canals compared to adults. These findings supplement earlier reports on the anatomical variations of the intraosseous vessel and nerve conduits of the maxilla. Surgical interventions in this area can be planned more precisely, taking into account the three-dimensional imaging, thus possibly protecting these sensitive structures.

Sudden Onset of Subcutaneous Air Emphysema After the Application of Air to a Maxillary Premolar Located in a Nonsurgical Field

Although rare, subcutaneous air emphysema can occur during dental procedures such as endodontic treatment, surgical extractions, and preparing a tooth for an indirect or direct dental restoration. We report the development of a subcutaneous air emphysema that was introduced through the periodontal ligament of an untreated premolar after the use of an air syringe to dry the tooth.

Evaluation of the morphology of the canalis sinuosus using cone-beam computed tomography in patients with maxillary impacted canines

Purpose

The nasopalatine canal is a well-known, important anatomical structure in the anterior maxilla, but this region contains many accessory canals. The canalis sinuosus (CS) is one of these canals; it contains the anterior superior alveolar nerve, along with veins and arteries. The purpose of this study was to evaluate the CS using conebeam computed tomography (CBCT) in patients with maxillary impacted canines.

Materials and Methods

A total of 111 patients admitted to the Istanbul Medipol University School of Dentistry for the exposure, orthodontic treatment, and/or extraction of an impacted canine were included in this study. CBCT images were obtained for these patients under standard conditions. Axial, coronal, and sagittal sections were evaluated to assess the prevalence of CS, the direction and diameter of the canal, its relation with the impacted canine, and its distance from the alveolar crest. Further, possible correlations with patient gender and age were analyzed.

Results

The CS could be detected bilaterally in all the evaluated tomography images. The mean canal diameter was significantly larger in males than in females (P=.001). The CS ran significantly closer to the impacted canine when the canal was located horizontally (P=.03). Variations of the canal, such as accessory canals, were identified in 6 patients.

Conclusion

CS is an anatomical entity that may resemble periapical lesions and other anatomical structures. Evaluation with CBCT prior to surgical procedures in the anterior maxilla will help to prevent overlooking such anatomical structures and to decrease possible surgical complications.

Effect of Three Different Injection Sites on the Success of Anterior Middle Superior Alveolar Nerve Block with 3% Mepivacaine: A Randomized Controlled Trial

AIM

Anterior middle superior alveolar (AMSA) nerve block injection targets the anterior superior alveolar nerve and the middle superior alveolar nerve branches of the infraorbital nerve through nutrient canals. Therefore, the central incisor to the second premolar teeth of one quadrant can be anesthetized. The aim of the present study was to evaluate the efficacy of AMSA nerve block injection with 3% mepivacaine solution at three different injection sites.

MATERIALS AND METHODS

In a double-blind crossover study, 47 volunteers participated and three AMSA nerve block injections of 3% mepivacaine solution without epinephrine were administered at the anterior, posterior, and the most common injection sites with a 1-week interval between injections. Anesthesia of the central incisor to the second premolar of the injected side was evaluated by using an electric pulp tester. The success of the injection was considered as lack of response to two consecutive 80 readings. The generalized estimating equation analytic tests were administered (α = 0.05).

RESULTS

The success rate of the AMSA nerve block injection ranged from 27.5-47.5% for the most common injection site and 22.5-42.5% for both the anterior and posterior injection sites.

CONCLUSION

Changing the injection site did not result in statistically significant improvements (p > 0.05).

CLINICAL SIGNIFICANCE

Changing the injection site anteropos-teriorly did not influence the success rate of the AMSA nerve block injection.

Patient-reported outcomes of implant placement performed concomitantly with transcrestal sinus floor elevation or entirely in native bone

AIM

Based on the hypothesis that maxillary sinus floor elevation with a transcrestal approach (tSFE) does not increase the morbidity of implant surgery, the study evaluated the patient-reported outcomes as well as the type and incidence of complications when implants are placed either concomitantly with tSFE (performed according to Trombelli et al. 2008, 2010a,b) or entirely in native bone.

METHODS

Data from the record charts of patients undergone implant placement for single-tooth rehabilitation in the posterior maxilla were retrospectively obtained from four clinical centers. Cases for tSFE group were included if they showed an extent of sinus lift ≥4 mm concomitantly to implant placement. Cases for N group were included when implant placement was performed entirely in native bone. Patient-reported outcomes had been assessed using 100-mm visual analog scales (postoperative pain, VAS_pain ) and visual rating scales (level of discomfort, VRS_discomfort ; willingness to undergo the same surgery, VRS_willingness ). The dose of analgesics had been self-recorded.

RESULTS

A convenience sample of 14 patients and 17 patients (contributing with one implant site each) treated with tSFE and N, respectively, was obtained for this study. Membrane perforation occurred in 1 tSFE case, without compromising the completion of the procedure. VAS_pain remained low (<12) in both groups. A tendency of VAS_pain to decrease with time was observed in both groups. The area under the curve for VAS_pain (AUC_pain ), indicating the level of pain experience through the first week following surgery, was 18.0 (IR: 8.5-85.0) and 11.5 (IR: 4.5-18.5) in tSFE and N groups, respectively, with no significant inter-group differences (P = 0.084). The dose of analgesics was similarly low between groups. No significant inter-group difference in VRS_discomfort and VRS_willingness was observed.

CONCLUSIONS

Implant placement performed either concomitantly with tSFE (according to Trombelli et al. 2008, 2010a,b) or entirely in native bone is associated with limited incidence of complications, low postoperative pain and medication and are both well tolerated.

[Recovery of maxillary tooth sensibility after Le Fort I osteotomy]

INTRODUCTION

Upper alveolar nerves, when injured during Le Fort I osteotomies, alter maxillary tooth sensitivity. We had for aim to analyze post-operative maxillary tooth sensitivity recovery.

MATERIAL AND METHODS

We conducted a prospective study in a series of patients having undergone Le Fort I osteotomy, with, or without mandibular osteotomy or intermaxillary disjunction (IMD). The direction and range of displacement of the maxillary bone were recorded. One tooth in each alveolar sector (incisivocanine, premolar, molar) was tested with an electric stimulator for each patient. The tests were performed before (D-1), and after surgery (D2 or day+2, D+15, M2 (or month +2), M3, and M6).

RESULTS

Twenty-two patients were included. Among the tested teeth, 91.9 % were sensitive at D-1. At D2, only 12.7 % of teeth were sensitive. At D15, M2, M3, and M6, the sensitivity was respectively 33.3 %, 43.1 %, 50 %, and 61.8 %. The recovery of sensitivity was faster in young patients (under 35 years of age) and for upper middle and superior alveolar nerves. There was no difference regarding the direction of maxillary movement.

DISCUSSION

Among the teeth that were sensitive before surgery, 87.3 % had not regained sensitivity at D2. The recovery of sensitivity increased at D15. A great displacement of the maxillary bone was an aggravating factor for loss of tooth sensitivity.

Posterior superior alveolar nerve blocks: a randomised controlled, double blind trial

BACKGROUND

Local anesthesia has been a boon for dentistry to allay the most common fear of pain among dental patients. Several techniques to achieve anesthesia for posterior maxillae have been advocated albeit with minor differences. We compared two techniques of posterior superior alveolar nerve block (PSANB), the one claimed to be "most accurate" to the one "most commonly used."

AIM

This study was conducted to assess and compare the efficacy as well as complications of "the straight needle technique" to that of "the bent needle technique" for PSANB.

PATIENTS AND METHODS

We conducted a prospective, randomised, double blind study on 120 patients divided into two groups, using a 26-gauge, 38 mm long needle with 2 ml of 2 % lignocaine hydrochloride with 1:200,000 adrenaline solution. Objective symptoms were evaluated by a single investigator. Cold test using ice was used to evaluate the status of pulpal anesthesia. Data thus obtained was subjected to statistical analysis.

RESULTS

Out of the 120 blocks, 19 blocks failed. Statistical analysis found straight needle technique to be more successful than the bent needle technique (p = 0.002). Both the techniques were equally effective for the first molar region on both right and left side (p = 0.66 on right side and p = 0.20 on left side). However, in the second and third molar region technique A was more effective than B (p = 0.01) on right side only. On Left side, both techniques were equally effective (p = 0.08). Sensitivity of the cold test was 82 % which is quite high but the specificity was 68 % which seems to be falling in the above average range only. Positive predictive value of 75 and negative predictive value of 76 was observed. We did not encounter any complications in this study.

CONCLUSION

To the best of our knowledge, this is the first randomised controlled clinical study on PSANB techniques. This study suggests that the PSANB using the straight needle technique as advocated by Malamed [1] can be routinely and safely used to achieve anesthesia in the maxillary molar region and to great efficacy, with normal precautions.

Loss of pulp vitality after maxillary sinus augmentation: a surgical and endodontic approach

BACKGROUND

Maxillary sinus augmentation is a routine procedure performed in implant dentistry in cases with sinus pneumatization. This study presents a series of clinical cases in which tooth devitalization occurred in conjunction with sinus augmentation.

METHODS

In the three cases presented, a sinus-lift procedure was performed that resulted in devitalization of the adjacent teeth. Patients were referred to an endodontist for evaluation and treatment. Vitality of the teeth was determined by the use of a cold test, electric pulp test, and cavity test. The pulp was considered to be necrotic if the tests were negative.

RESULTS

In this case series, loss of pulp vitality of two maxillary left second premolars and one maxillary left first molar occurs after sinus-augmentation procedures. The devitalized teeth were free of caries. In one case, two amalgam restorations were present.

CONCLUSION

Pulp necrosis may occur in conjunction with a sinus-lift procedure in cases when an adjacent root is in close proximity to the sinus floor and the sinus membrane is elevated over the root apex.

Anterior and middle superior alveolar nerve block for anesthesia of maxillary teeth using conventional syringe

Background:

Dental procedures in the maxilla typically require multiple injections and may inadvertently anesthetize facial structures and affect the smile line. To minimize these inconveniences and reduce the number of total injections, a relatively new injection technique has been proposed for maxillary procedures, the anterior and middle superior alveolar (AMSA) nerve block, which achieves pulpal anesthesia from the central incisor to second premolar through palatal approach with a single injection. The purpose of this article is to provide background information on the anterior and middle superior alveolar nerve block and demonstrate its success rates of pulpal anesthesia using the conventional syringe.

Materials and Methods:

Thirty Caucasian patients (16 men and 14 women) with an average age of 22 years-old, belonging to the School of Dentistry of Los Andes University, were selected. All the patients received an AMSA nerve block on one side of the maxilla using the conventional syringe, 1 ml of lidocaine 2% with epinephrine 1:100.000 was injected to all the patients.

Results:

The AMSA nerve block obtained a 66% anesthetic success in the second premolar, 40% in the first premolar, 60% in the canine, 23.3% in the lateral incisor, and 16.7% in the central incisor.

Conclusions:

Because of the unpredictable anesthetic success of the experimental teeth and variable anesthesia duration, the technique is disadvantageous for clinical application as the first choice, counting with other techniques that have greater efficacy in the maxilla. Although, anesthetizing the teeth without numbing the facial muscles may be useful in restorative dentistry.

Neurovascular anatomical variations in the anterior palate observed on CBCT images

OBJECTIVE

This study aimed to assess the presence of additional foramina and canals in the anterior palate region, through cone beam computed tomography (CBCT) images, describing their location, direction, and diameter.

MATERIALS & METHODS

CBCT exams of 178 subjects displaying the anterior maxilla were included and the following parameters were registered: gender; age group; presence of additional foramina in the anterior palate (AFP) with at least 1 mm in diameter; location and diameter of AFP; and direction of bony canals associated with AFP.

RESULTS

Twenty-eight patients (15.7%) presented AFP and in total 34 additional foramina were registered. No statistical differences between patients with or without AFP were found for gender or age. The average diameter of AFP was 1.4 mm (range from 1 to 1.9 mm). Their location was variable, with most of the cases occurring in the alveolar process near the incisors or canines (n = 27). In 18 cases, AFP was associated with bony canals with upward or oblique direction toward the anterior nasal cavity floor. In 14 cases, the canal presented as a direct extension of the canalis sinuosus, in an upward direction laterally to the nasal cavity aperture. In two cases, the canal was observed adjacent to the incisive and joined the nasopalatine canal superiorly.

DISCUSSION

CBCT images have a crucial role in the recognition of anatomical variations by allowing detailed tridimensional evaluations. Additional foramina and canals in the anterior region of the upper jaw are relatively frequent. Practitioners should be aware and trained to identify these variations.

CONCLUSIONS

Over 15% of the population studied had additional foramina in the anterior palate, between 1 mm and 1.9 mm wide, with variable locations. In most cases the canals associated with these foramina either presented as a direct extension of the canalis sinuosus, or coursed towards the nasal cavity floor.

A prospective, randomized, single-blind comparative evaluation of anesthetic efficacy of posterior superior alveolar nerve blocks, buccal infiltrations, and buccal plus palatal infiltrations in patients with irreversible pulpitis

INTRODUCTION

The purpose of this study was to evaluate and compare the anesthetic efficacy of posterior superior alveolar (PSA) nerve blocks, buccal infiltrations, and buccal plus palatal infiltrations with 2% lidocaine with 1:200,000 epinephrine in maxillary first molars with irreversible pulpitis.

METHODS

Ninety-four adult patients participated in this prospective, randomized, single-blinded study. The patients were divided into 3 treatment groups on a random basis. Twenty-eight patients received a PSA nerve block, 33 patients received buccal infiltrations, and 33 patients received buccal plus palatal infiltrations with 2% lidocaine with 1:200,000 epinephrine. Endodontic access preparation was initiated 15 minutes after injection. Pain during treatment was recorded using a Heft-Parker visual analog scale. Success was recorded as "none" or "mild" pain.

RESULTS

Statistical analysis using nonparametric chi-square tests revealed that there was no statistical difference between the anesthetic success of PSA nerve blocks (64%), buccal infiltrations (54%), and buccal plus palatal infiltrations (70%).

CONCLUSIONS

None of the tested methods gave 100% anesthetic success rates in maxillary first molars with irreversible pulpitis.

Influence of the maxillary sinus exposure in reduction malarplasty with an L-shaped osteotomy

BACKGROUND

The zygomatic bone forms the prominence of the midface and plays an important role in determining the human facial attractiveness. The Oriental face is mesocephalic, with a prominent zygomatic body and wide zygomatic arch. Nevertheless, as an oval face is considered ideal, reduction malarplasty is always requested by Oriental people. Currently, L-shaped zygomatic osteotomy is often reported in literature yet no previous study has documented the exact outcome of this approach after exposure of the maxillary sinus. The objective of the study was to investigate the outcome and complications of intraoral L-shaped zygomatic osteotomy with the opening of maxillary sinus.

METHOD

All patients were subjected to computed tomography before and 12 months after surgery. All parameters were obtained with morphometric analysis for clinical evaluation, so as to reveal the change in maxillary sinus, postsurgical results, and complications.

RESULTS

All patients were satisfied with the optimal outcome of reduction malarplasty. Morphometric analysis indicated that the volume and surface area of maxillary sinus statistically significantly changed before and after surgery. Complications included deeper nasolabial fold, infraorbital nerve injury, and so on, yet no patients reported infection or dental pulp necrosis.

CONCLUSIONS

Intraoral L-shaped osteotomy of the zygoma can improve the appearance of the patients greatly, and the exposure of maxillary sinus caused only a few complications.

Transient diplopia with ipsilateral abducent nerve palsy and ptosis following a maxillary local anesthetic injection: a case report and review of literature

BACKGROUND

The posterior superior alveolar (PSA) nerve block is commonly used in dentistry for treatment of the maxillary molars. Although this procedure is associated with many complications, ocular complications have been rarely reported.

CASE REPORT

This report details an iatrogenic paresis of the abducent nerve and partial palsy of the oculomotor nerve leading to diplopia, strabismus and ptosis following a PSA nerve block and extraction of maxillary right second molar. The patient was treated symptomatically, and the recovery was uneventful. Relevant anatomical pathways with review of literature are discussed.

DISCUSSION

Although rare, the dentist should be aware of these complications to avoid being perplexed by this unexpected circumstance, thus adversely affecting the doctor-patient trust.

A review of the mandibular and maxillary nerve supplies and their clinical relevance

Mandibular and maxillary nerve supplies are described in most anatomy textbooks. Nevertheless, several anatomical variations can be found and some of them are clinically relevant. Several studies have described the anatomical variations of the branching pattern of the trigeminal nerve in great detail. The aim of this review is to collect data from the literature and gives a detailed description of the innervation of the mandible and maxilla. We carried out a search of studies published in PubMed up to 2011, including clinical, anatomical and radiological studies. This paper gives an overview of the main anatomical variations of the maxillary and mandibular nerve supplies, describing the anatomical variations that should be considered by the clinicians to understand pathological situations better and to avoid complications associated with anaesthesia and surgical procedures.

Infra-orbital nerve block anesthesia-extended coverage using intra-oral 'molar approach'

The maxillary teeth are supplied by the anterior, middle and posterior superior alveolar nerves. The anterior and middle superior alveolar (AMSA) nerves exit the skull from the infra-orbital foramen, where they can be blocked for procedures on the maxillary anteriors and premolars. Sometimes, the middle superior alveolar nerve has a variant course and is not blocked by the conventional block technique. A new technique has been described for blocking the AMSA nerves, keeping in view the alternate pathway of the middle superior alveolar nerve.

A prospective, randomized, double-blind comparison of the anesthetic efficacy of two percent lidocaine with 1:100,000 and 1:50,000 epinephrine and three percent mepivacaine in the intraoral, infraorbital nerve block

INTRODUCTION

The purpose of this prospective, randomized, double-blind study was to compare the anesthetic efficacy of 2% lidocaine with 1:100,000 epinephrine, 2% lidocaine with 1:50,000 epinephrine, and 3% mepivacaine in the intraoral, infraorbital nerve block.

METHODS

Forty subjects randomly received intraoral, infraorbital nerve blocks by using a cartridge of 2% lidocaine with 1:100,000 or 1:50,000 epinephrine and a cartridge of 3% mepivacaine at 3 separate appointments spaced at least 1 week apart. The anteriors, premolars, and first molar were pulp tested in 4-minute cycles for a total of 60 minutes.

RESULTS AND CONCLUSIONS

The intraoral, infraorbital nerve block was ineffective in providing profound pulpal anesthesia of the maxillary central incisor, lateral incisor, and first molar. Successful pulpal anesthesia of the canine and first and second premolars ranged from 75%-92% by using 2% lidocaine with 1:100,000 and 1:50,000 epinephrine. However, pulpal anesthesia did not last for 60 minutes. The use of 3% mepivacaine provided a shorter duration of anesthesia than the lidocaine formulations with epinephrine in the canines and premolars.

Effectiveness of nasopalatine nerve block for anesthesia of maxillary central incisors after failure of the anterior superior alveolar nerve block technique

The purpose of this study was to assess the effectiveness of nasopalatine nerve block for anesthesia of maxillary central incisors after failure of the anterior superior alveolar nerve (ASAN) block technique. Secondarily, the possible innervation of the maxillary central incisors by the nasopalatine nerve was also investigated. Twenty-seven healthy, young adult volunteers (age: 17-26 years; gender: 9 males and 18 females) were enrolled in this study. All participants were undergraduate dental students of the University of Vale do Rio Verde de Três Corações. The volunteers had the anterior superior alveolar nerves anesthetized and a thermal sensitivity test (cold) was performed on the maxillary central incisors. The volunteers that responded positively to cold stimulus received a nasopalatine nerve block and the thermal sensitivity test was repeated. All participants were anesthetized by a single operator. Three patients presented sensitivity after both types of bilateral blocks and were excluded from the percentage calculations. In the remaining 24 patients, 16 had their maxillary central incisors anesthetized by the anterior superior alveolar block and 8 remained with sensitivity after the ASAN block. All these 8 patients had their maxillary central incisors successfully anesthetized by the nasopalatine block. In this study, 33.3% of the subjects had the innervation of one or both maxillary central incisors derived from the nasopalatine nerve, whilst most subjects (66.7%) had such teeth innervated by the anterior superior alveolar nerve. The nasopalatine nerve block was effective in anesthetizing the maxillary central incisors when the anterior superior alveolar nerve block failed.

Dental Pulp Necrosis as a Rare Complication of Reduction Malarplasty

Reduction malarplasty through the intraoral or the combined approach using intraoral and preauricular incisions is widely performed as an aesthetic surgical procedure in northeast Asia. The authors recently examined a patient who underwent this type of surgery and presented with discoloration of both upper canine teeth that was diagnosed as pulp necrosis. This case suggests the possibility that pulp necrosis occurs as a result of vibration and heat energy transmitted from a rotating bur to the anterior superior alveolar nerve branch located in the more lateral and superficial portion than in the normal position. Although pulp necrosis is extremely rare, it is hoped that this case will heighten the awareness of surgeons to this potential complication.

Patterns of innervation of the anterior maxilla: a cadaver study with relevance to canine fossa puncture of the maxillary sinus

OBJECTIVES/HYPOTHESIS

Complications from canine fossa puncture of the maxillary sinus are caused by damage to the anterior superior alveolar nerve (ASAN) and the middle superior alveolar nerve (MSAN). The aim of this study was to elucidate the pattern of ASAN and MSAN within the anterior maxilla and to secondly determine suitable surgical landmarks to aid in accurately localizing the area of the canine fossa least likely to produce complications when a trocar is passed into the maxillary sinus.

METHODS

Anatomic dissection of the anterior face of the maxilla from 20 cadaver heads was performed. The pattern and presence of the ASAN and MSAN was identified on each side and tabulated. Landmarks for the safest entry point for canine fossa puncture were determined, and each side had a puncture placed using these landmarks. Any disruption of nerves was noted.

RESULTS

Multiple differing patterns of ASAN were identified. The ASAN emerged from its foramen as a single trunk in 30 (75%) sides and in a double trunk in 10 (25%). In 24 (60%), single or multiple branches from the ASAN trunks were identified. A MSAN was identified in 9 (23%) maxillae. The safest entry point for a canine fossa puncture was where a vertical line drawn through the mid-pupillary line was bisected by a horizontal line drawn through the floor of the pyriform aperture.

CONCLUSIONS

There is significant variation in the pattern of ASAN and MSAN within the anterior face of the maxilla. By using the newly described landmarks when performing a canine fossa puncture, there is reduced risk of damage to these nerves and provides a reliable point to enter the maxillary sinus.

Computed tomography pseudofractures of the mid face and skull base

Thin-section multislice CT delineates numerous normal skull-base and mid-facial bony discontinuities. These represent sutures, fissures and neurovascular foramina or channels, and should be differentiated from fractures. This pictorial review describes and illustrates the characteristic location and multiplanar CT appearances of these structures. Their clinical significance in terms of pathological processes and surgical planning are discussed.

The key to profound local anesthesia: neuroanatomy

BACKGROUND

To achieve profound dental local anesthesia, it is necessary for the dentist to have a thorough knowledge of the details of sensory innervation to the maxilla and mandible. Since the early 1970s, dentistry has experienced a resurgence of interest in the neuroanatomical basis of local anesthesia, resulting in numerous scientific reports on the subject.

OVERVIEW

Current studies afford a more detailed knowledge of the branching of various divisions of the trigeminal nerve, the great sensory nerve of the head region. In this article, the authors provide an update of the peripheral distribution of the trigeminal nerve to enhance induction of safe and effective dental local anesthesia.

CONCLUSIONS AND PRACTICAL IMPLICATIONS

An understanding of the potential variations in innervation should help the dentist improve his or her ability to induce profound local anesthesia.

Injection regimen for anesthesia of the maxillary first molar

This study evaluated whether a single or double injection is required to achieve first molar anesthesia. Subjects received posterosuperior alveolar nerve blocks. Presence or absence of anesthesia was evaluated with carbon dioxide dry ice pulp sensitivity testing. This was followed by mesial infiltration and a second pulp testing. The posterosuperior alveolar nerve block alone usually provided effective first molar anesthesia. A small percentage of subjects required an additional mesial infiltration to obtain anesthesia.

Patterns of innervation of the maxillary first molar: a dissection study

Human maxillae were dissected with the aim of tracing nerves from maxillary first molar root apices to their parent superior alveolar nerve branches. The contribution of the posterior, middle, and anterior superior alveolar nerves to the innervation of the first molar was assessed. The posterior superior alveolar nerve was found to contribute innervation 100% of the time; the middle superior alveolar nerve, when present, contributed innervation 28% of the time. The anterior superior alveolar nerve did not supply any innervation to the first molar.