Posterior Superior Alveolar Research Articles

Considering Anatomic Features When Retrieving a Separated Needle: A Case Report Using CT Navigation Within the Infratemporal Fossa

Needle separation is an unfortunate complication encountered during local anesthetic administration in dentistry. Attributing factors have been thought to be related to needle gauge, pre-injection needle bending, needle deflection, redirection, and depth of penetration. Various methods have been described for FB identification and retrieval. We present a case of a separated hypodermic needle in the infratemporal fossa after a posterior superior alveolar (PSA) nerve block. We describe the use of computed tomography (CT) navigation system with an expanded armamentarium of guided instrumentation. Utilization of our method can efficiently aid in the localization and removal of foreign bodies in the maxillofacial region.

Intraosseous arterial alteration of maxilla influencing implant-related surgeries.

To investigate the intraosseous arterial pathways and anastomoses in the alveolar aspects of the maxilla in order to better understand the arterial scattering pattern. Eleven cadavers were selected for macroscopic intraosseous arterial analyses by corrosion casting. The red-colored acrylic resin was injected into the external carotid arteries. The specimens were kept in an enzymatic solution at 36°C for about 60days, depending on the process progression. After removal of the soft tissues and drying, the bone was macerated by potassium hydroxide to analyzethe course and the mean diameters of the intraosseous anastomoses. Vertico-oblique and horizontal intraosseous arteries and anastomoses between the greater palatine-, posterior superior alveolar-, and infraorbital arteries were detected. The vertico-oblique anastomoses were found on the anterolateral wall of the maxilla and the alveolar crest with a mean diameter of 0.46mm; nevertheless, the horizontal (transalveolar) anastomoses were identified in the interdental septum/alveolar crest with the mean diameter of 0.41mm. From the horizontal anastomoses, small intraseptal branches supplied the territory of the alveolar socket in various directions. The localization of intraosseous arterial anastomoses is critical in implant-related surgeries, predominantly to maintain proper circulation. Based on vertico-oblique and transalveolar anastomoses, simultaneous buccal- and palatal flap elevation (particularly on the palatal side) should be avoided to minimize patient morbidity and intra- or postoperative complications. Moreover, preserving transverse loops in the interdental septum is essential during implant surgeries, which can significantly influence collateral periosteal and osteal circulation to prevent ischemia.

Comparison of posterior superior alveolar and greater palatine nerve block with local infiltration for extraction of maxillary molars in oral surgery – A randomized controlled trial

Administration of local anesthetic drug that prevents pain during dental treatment is of absolute importance. Act of injecting local anesthetic should be nonpainful and atraumatic. The maxilla is very porous and highly vascular. Therefore, anesthesia of maxillary teeth can be accomplished more easily than with mandibular teeth. The aim of this study is to determine the anesthetic efficacy of the conventional technique of posterior superior alveolar (PSA) and greater palatine nerve(GP) block anesthesia as compared to the buccal and palatal technique in terms of pain during injection, after extraction, after 15mins of the procedure and quality of anesthesia during the extraction procedure. The study also intends to determine the incidence of positive aspiration in the infiltration technique. This randomized clinical study was carried out on 154 patients who reported to the Department of Oral and Maxillofacial Surgery, Sri Rajiv Gandhi College of Dental Sciences & Hospital Bangalore, requiring extraction of maxillary second and third molar teeth. The patients received anesthesia using the conventional nerve block technique and infiltration technique randomly on each side of the mouth. Patients were assessed for pain during the injection, after extraction, and after 15mins of the procedure with each technique using Visual Analog Scale (VAS). The patients were also assessed for pain using the Verbal Response Scale (VRS). The positive aspiration was assessed for each technique. During tooth extraction, quality of anesthesia was assessed using an eight-point category rating scale. The results obtained were analyzed using Chi-square test. It was concluded that the buccal infiltration technique is less painful for the patient as compared to the posterior superior alveolar nerve block. This technique has a lower frequency of positive aspiration as compared with the PSA nerve block. However, the PSA nerve block technique provides better-quality of anesthesia. It can be concluded that the infiltration technique appears to be a successful alternative with additional advantages, as compared to the nerve block technique.

Comparative study of analgesia of ketorolac, tramadol, and flupirtine in the management of third molar surgery.

Introduction:The most commonly performed surgical procedure in most oral and maxillofacial surgery practices is the removal of third molars. Postoperative pain is considered a form of acute pain due to surgical trauma with an inflammatory reaction.Materials and Methods:One hundred and fifty patients were included in the study which were divided into GROUP-A, B, and C-50 patients each; those who underwent third molar removal under local anesthesia. Local anesthesia was obtained by inferior alveolar, lingual, long buccal, posterior superior alveolar, and greater palatal nerve block injections after first complain of pain, all patients were prescribed analgesics (Ketorolac-10 mg), (Tramadol-50 mg), (Flupirtine-100 mg), and antibiotics co-amoxiclav-625 mg) T. D. S in all the three groups A, B, C, respectively, for 5 days and the timing noted in the patients assessment sheet. The statistical analysis was done using SPSS Version 15.0 statistical analysis software.Results:The flupirtine group has early onset and also had minimum side effects. All the groups showed similar trend in change in pain score from 3 h. P. O to different time intervals. It was observed the pain score increased significantly till 6 h. Post operative a decreased trend was found at 24 h, 48 h, 78 h, after 6 h. and this change was found to be statistically significant for all three groups.Conclusion:Flupirtine had faster onset and comparable pain management profile as compared to tramadol, it also had minimum side effects, hence the use of flupirtine might be recommended for postoperative pain management in cases undergoing third molar surgery.

Evaluation of the posterior superior alveolar artery canal by cone-beam computed tomography in a sample of the Egyptian population.

PurposeThis study was conducted to evaluate the accuracy of cone-beam computed tomography (CBCT) in detecting the posterior superior alveolar (PSA) artery canal in a sample of the Egyptian population.Materials and MethodsCBCT images of 600 maxillary sinuses of patients were examined for the presence or absence of the PSA artery along the lateral wall of the maxillary sinus, and for the diameter and type of the canal in relation to age and sex. The distances from the canal to the alveolar crest and sinus floor were also measured. Each canal was assessed to determine whether it was bifid.ResultsThe PSA artery canal could be detected in 92.0% of the sinuses. The mean distance from the inferior border of the PSA artery canal to the sinus floor was 8.2±2.2 mm (range, 3.2–13.6 mm) in males and 7.3±2.1 mm (range, 3.0–13.1 mm) in females. The mean distance from the inferior border of the PSA artery canal to the alveolar crest was 18.2±2.7 mm (range, 11.0–23.9 mm) in males and 17.4±2.3 mm (range, 10.8–23.5 mm) in females. The mean diameter of the PSA artery canal was larger in male subjects. The PSA artery canal was bifid in 8.7% of cases. The most frequently observed location of the PSA artery canal was intraosseous (82.2%).ConclusionCBCT was confirmed to be a valuable tool for evaluation and localization of the PSA artery before maxillary sinus lift surgery to avoid intraoperative bleeding.

Reinforcing Teaching Strategies with Demonstrational Videos in Dental Education

Introduction: Blended learning is the trending concept in current educational system including the field of dentistry where traditional teachings are combined with online resources such as demonstrational videos etc. Aims and Objectives: To assess whether demonstrational videos help enhance dental student’s confidence, knowledge and technique during local anesthesia injection. Methods: Fifty dental students of year 3 (B.D.S.) of SEGi University were randomly allocated into two groups. Both groups were given live demonstration of the posterior superior alveolar (PSA) nerve injection technique. In addition, the test group received additional demonstrational video to watch. Then both the groups were made to inject on each other. Two oral surgeons assessed both the groups individually on some fixed criteria for injection technique. The data were collected and analyzed using SPSS version 22, mean values and percentages were compared between 2 groups using independent sample t-test and Chi-square test respectively. Results: The mean score for injection technique was 1.4038 in control group and 1.6957 in the test group with p=0.004. In other aspects of this study, there was no significant difference found. Conclusion: Demonstrational videos helped improve injection technique among dental undergraduates.

Microsurgical anatomy of the maxillary artery for extracranial-intracranial bypass in the pterygopalatine segment of the maxillary artery.

The extracranial-intracranial (EC-IC) bypass using the maxillary artery (MA) has been successfully completed using a radial artery (RA) graft but the complicated anatomy and narrow exposure make it difficult. The purpose of this article is to define the microsurgical exposure of the MA through the middle fossa and describe the branches, diameter, and length of the MA available for the EC-IC bypass in the sphenopalatine fossa and anterior part of the infratemporal fossa. 5 cadaveric specimens were dissected bilaterally (10 MA dissections) to define the microsurgical anatomy of the MA through an intracranial approach. The exposable branches of the MA at the level of the infratemporal and sphenopalatine fossae were the anterior deep temporal, posterior superior alveolar, and infraorbital arteries. The origin of each branch could be exposed. The available section of the MA for use as a donor vessel is between the origin of the anterior deep temporal artery and the infraorbital artery. The mean exposable length of the MA was 19.4 mm. The mean outer diameter of the donor MA was 3.2 mm. Tension-free EC-IC bypass was possible using a RA graft between the MA and the middle cerebral artery, the MA and the supraclinoid internal carotid artery (ICA), or the MA and the petrous ICA. Exposure of the MA at the infratemporal and sphenopalatine fossae is complicated but provides length and diameter suitable as a donor artery for the EC-IC bypass. Clin. Anat. 31:724-733, 2018. © 2017 Wiley Periodicals, Inc.

Cadaveric Study for Intraoral Needle Access to the Infratemporal Fossa: Application to Posterior Superior Alveolar Nerve Block Technique.

The posterior superior alveolar (PSA) nerve block is, from an anatomical perspective, challenging because the mandibular ramus and the zygomatic process of the maxilla can interfere with the course of the needle. Dentists empirically know that shifting the patient’s mandible to the ipsilateral side can improve visibility and accessibility for such blocks. This cadaveric study aimed to establish anatomical evidence for the ipsilateral mandible shifting used in the PSA. The distance between the lateral most bulging point of the alveolar part of the maxilla and ipsilateral anterior border of the ramus of the mandible ranged from 1.4 to 6.9 mm with a mean of 4.3 ± 1.6 mm. This result supports the empirical technique of shifting the mandible ipsilaterally for PSA nerve block.

The Efficacy of Buccal Infiltration of 4% Articaine and PSA Injection of 2% Lidocaine on Anesthesia of Maxillary Second Molars.

Introduction:During the early mixed dentition period, the location of the deciduous maxillary second molar results in ineffectiveness of the infiltration technique in this area. In such cases, administration of posterior superior alveolar (PSA) nerve block is recommended; however, such a technique has some complications. The present study was undertaken to compare the effects of buccal infiltration of 4% Articaine and PSA technique with 2% Lidocaine on the success of anesthesia of maxillary deciduous second molars in 6 to 9-year old children. Methods and Materials: In the present double-blind randomized clinical trial, 56 children aged 6-9 years requiring vital pulp therapy of deciduous maxillary second molar were included. In group 1, 4% Articaine was injected using a buccal infiltration technique. In group 2, 2% Lidocaine was injected using the PSA nerve block technique. After 10 min, the caries was removed and access cavity preparation was instituted. The patients were asked to report the presence or absence of pain during the procedure. Therefore, the existence of pain was measured by the patient's self-report. Data were analyzed with descriptive statistical methods and the chi-squared test. Results:Pain was reported by 6 (21.4%) and 9 (32.1%) subjects in the Articaine and Lidocaine groups, respectively. Chi-squared test did not reveal any significant differences between the two groups (P=0.54). Conclusion:Under the limitations of the present study, there was no significant differences between the results of Articaine buccal infiltration and Lidocaine PSA technique, so Articaine buccal infiltration can be used as a substitute for the PSA technique.

Maxillary Sinus Dimensions With Respect to the Posterior Superior Alveolar Artery Decrease With Tooth Loss.

The posterior superior alveolar (PSA) artery is frequently encountered in the area where the lateral osteotomy is performed during direct sinus augmentation procedures. To investigate the correlation between patient-dependent variables and measurements related to PSA using cone beam computed tomography (CBCT) data. Three hundred ninety-four CBCT scans were evaluated to assess the PSA artery diameter and distances to the sinus floor and to alveolar crest. Patient's age, gender, and edentulism status were recorded. The PSA artery tends to be wider in older patients. Distances to the sinus floor or the alveolar crest tend to be shorter in women and in partially and completely edentulous patients. Also, as those distances decrease, the mediolateral width of the sinus increases. Tooth loss leads to maxillary sinus vertical collapse with respect to the PSA artery. The position of the artery is stable; so, the mediolateral dimensions at different heights from the floor increase. The reduced distances from the PSA to the sinus floor and the alveolar crest in edentulous patients potentially increase the risk of injury during maxillary sinus lift. Additionally, when the distance to the sinus floor decreases, the mediolateral dimensions of the sinus at different heights increase, which may complicate the technique and challenge the outcomes.

Anaesthesia Techniques for Maxillary Molars - A Questionnaire-Based Retrospective Field Survey of Dentist in Western India.

Clinicians use various anaesthesia techniques like Posterior Superior Alveolar (PSA) nerve block, buccal infiltration with or without supplemental anaesthesia like palatal and intraligamentary infiltrations for root canal treatment in maxillary molars. However there is no general consensus regarding which technique is enough for performing endodontic treatment in maxillary molars. The aim of this questionnaire-based survey is to compare and evaluate the various techniques used to anaesthetize the maxillary molars and its effect on postoperative pain. The data were obtained from 290 dental practitioners using a specially prepared questionnaire survey conducted anonymously. The questionnaire contained questions covering data such as years in dentistry, acquired specialty, techniques used for anaesthetizing maxillary molars, success of anaesthesia, and postoperative pain, etc. Buccal infilteration with supplemental anaesthesia in the form of palatal (82%) and intra-ligamentary infilteration (88%) show higher success rate compared to only buccal infilteration (69%). However, intra-ligamentary infilteration group showed highest rate (75%) of postoperative pain. General practitioners (62% of clinicians) prefer to give both buccal and palatal infilterations and specialists opt for only buccal infilteration (66-74% of specialists). Only buccal infilteration is sufficient during root canal treatment of maxillary molars. Routine use of supplemental anaesthesia in the form of palatal and intra-ligamentary infilteration is not necessary unless patient experiences discomfort during endodontic treatment. However, intra-ligamentary infilteration may lead to postoperative discomfort in the form of pain.

Prevalence of the posterior superior alveolar canal in cone beam computed tomography scans

This study was primarily aimed at determining the prevalence of the posterior superior alveolar (PSA) canal in cone beam computerized tomography (CBCT) scans in a North American population. Cone beam computed tomography scans were selected on the basis of predetermined eligibility criteria from a pool of 976 data sets. Two calibrated examiners assessed the presence of PSA canal on the postero-lateral wall of the maxillary sinus using coronal sections. One examiner also recorded the presence of images compatible with sinus disease. Associations between the presence of PSA canal and sinus disease were investigated for males and females separately using statistical methods. A total of 254 CBCT scans were selected. The pooled prevalence of the PSA canal in CBCT scans was 94.4% and 91% on the right and left side, respectively. The ability to detect the presence of the canal was not significantly affected by the presence of intrasinusal disease. Males are more likely than females to present signs of maxillary sinus pathoses on the right (63.3% vs. 36.7%) and the left side (59.2% vs. 40.8%). The prevalence of the PSA canal on CBCT images in the selected population is high. The PSA canal can be consistently visualized on CBCT scans with a high level of reproducibility regardless of the presence of radiographic signs of intrasinusal pathoses.

Ocular complications after posterior superior alveolar nerve block: a case of trochlear nerve palsy

Many intraoperative complications occurring during third molar surgery are described in the literature. Unilateral trochlear nerve palsy secondary to dental anaesthesia is a rare complication. We report the case of a 36-year-old healthy man, ASA I classification, requiring upper third molar extraction. Articaine 1:200,000 epinephrine for right posterior superior alveolar (PSA) nerve block was administered locally in the mucobuccal fold above the upper third molar. A few minutes after PSA nerve block the patient experienced double-vision. The patient was subsequently visited by an ophthalmologist and the condition was diagnosed as transient unilateral vertical diplopia due to temporary paralysis of the superior oblique muscle as a result of the anaesthetic solution involving the IV cranial nerve. The authors report this unusual case and discuss the possible anatomical pathways that might explain this rare phenomenon.

Articaine Diffusion in Oral Tissues

Objetivo: Avaliar a difusao do anestesico articaina a 4% com adrenalina 1:100.000 em dentes maxilares e mandibulares, injetado atraves do bloqueio do nervo alveolar superior posterior (NASP). Metodo: Foram realizados 50 procedimentos anestesicos do bloqueio do NASP em voluntarios e avaliou-se a sensibilidade da mucosa atraves do teste pin-prick e a sensibilidade pulpar atraves do teste eletrico pulp tester. As estruturas avaliadas foram: mucosa palatal posterior (tuber), mucosa palatal anterior, mucosa jugal, mucosa vestibular de molares, lingua, labio inferior, primeiro pre-molar inferior (1PMI), incisivo lateral inferior (ILI), primeiro molar inferior (1MI), primeiro pre-molar superior (1PMS), incisivo lateral superior (ILS), primeiro molar superior (1MS). Resultados: Foi observado que, ao analisar a insensibilidade mucosa, a efetividade da articaina em insensibilizar as estruturas testadas quando administrada atraves do bloqueio do NASP foi crescente com o decorrer do tempo e que os 1MS e 1PMS tiveram um tempo de latencia inferior as demais unidades dentarias testadas. Observou-se que a insensibilidade pulpar foi crescente com o decorrer do tempo e que os 1MS e 1PMS tiveram um tempo de latencia inferior as demais unidades dentarias testadas. O ILS e as unidades dentarias inferiores 1MI e 1PMI necessitaram de um tempo de latencia de 4 minutos para comecarem a apresentar insensibilidade pulpar. Os ILI apresentaram o maior indice de insucesso de anestesia pulpar (74%) e o insucesso da anestesia do 1MS foi de 6%, a menor entre os dentes testados. Conclusoes: Os resultados sugerem haver uma difusao da articaina no sentido ântero-posterior na maxila e a difusao vestibulo-palatal da droga. A articaina quando administrada atraves do bloqueio do NASP suprime a necessidade da anestesia do palato.

Transient diplopia with ipsilateral abducent nerve palsy and ptosis following a maxillary local anesthetic injection

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. 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. 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 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.

PSA block for maxillary molar's anesthesia - an obsolete technique?

Routine use of posterior superior alveolar (PSA) nerve block or maxillary infiltration for the removal of maxillary molars has been validated. The present study was undertaken to determine the relative contribution of posterior superior alveolar (PSA) block in cases of anesthesia required for maxillary molars. One hundred patients requiring removal of maxillary second and third molars were enrolled. These patients were divided into 2 groups. One group received infiltration for anesthesia and other group received PSA nerve block using lignocaine with vasoconstrictor. All extractions were performed using a consistent technique of intraalveolar extraction. Data relating to the pain during extraction obtained on a visual analog scale and a verbal response scale, requirement of repeated injection for anesthesia, efficacy of these injections in localized infections, and requirement of rescue analgesics 3 hours after extraction. Statistical data confirmed clinical equivalence between infiltration and PSA nerve block. Considering the difficulty in mastering the technique of PSA nerve block, and the possibility of more complications associated with it (compared with infiltration); it may not be necessary for anesthesia of maxillary molars.

Diplopia with local anesthesia

A variety of local and systemic complications can occur during the administration of local anesthesia (LA). Diplopia is one of the very rare complications that follow a posterior superior alveolar (PSA) nerve block. This article describes a very rare case report and the possible mechanisms are discussed in detail. Diplopia is defined as double vision. The patient was administered PSA nerve block for the extraction of the upper right third molar tooth. After the extraction, the patient complained of double vision and not being able to gaze laterally with the right eye. The patient recovered completely after the anesthetic effect. Local and systemic complications do occur during and after administration of local anesthesia. The clinician needs to be aware of the complications and management.

Anesthetic Efficacy of 1.8 Milliliters and 3.6 Milliliters of 2% Lidocaine with 1:100,000 Epinephrine for Posterior Superior Alveolar Nerve Blocks

IntroductionThe purpose of this prospective, randomized, single-blinded study was to measure the degree of anesthesia obtained with 1.8 mL and 3.6 mL of 2% lidocaine with 1:100,000 epinephrine in posterior superior alveolar (PSA) nerve blocks. MethodsThirty-one adult subjects randomly received PSA nerve blocks of 1.8 mL and 3.6 mL of the lidocaine solution at 2 separate appointments in a crossover design. An electric pulp tester was used to test for anesthesia of the first and second molars and premolars in 3-minute cycles for 50 minutes. Anesthesia was considered successful when 2 consecutive 80 readings were obtained within 15 minutes. Results and ConclusionsAnesthetic success for the 1.8 mL volume of 2% lidocaine with 1:100,000 epinephrine was 97% for the second molar and 77% for the first molar. Anesthetic success for the 3.6 mL volume of 2% lidocaine with 1:100,000 epinephrine was 100% for the second molar and 84% for the first molar. The differences were not statistically significant between the 2 anesthetic volumes. Anesthetic success for the premolars for both volumes was in the low to moderate range and would not provide predictable pulpal anesthesia. For the first molar, the 3.6 mL volume of the lidocaine formulation provided a statistically longer duration of pulpal anesthesia than the 1.8 mL volume. The pain of depositing a 3.6 mL volume of a lidocaine solution was not statistically more painful than depositing a 1.8 mL volume.

The clinical anatomy of complications observed in a posterior superior alveolar nerve block

The use of anesthetics in dentistry is necessary to prevent pain in precise areas of the oral cavity. This is accomplished by blocking branches of the trigeminal nerve. For treatment of the maxillary molars (with the possible exception of the mesiobuccal root of the 1st maxillary molar) and the buccal soft tissues, a posterior superior alveolar (PSA) nerve block is employed. This injection targets the PSA nerve in the infratemporal fossa. To properly perform the injection, deposition of the anesthetic needs to be placed along the posterior surface of the maxilla. The needle must be advanced approximately 15mm in the following x-y-z plane at the same time to reach the PSA nerve along the posterior surface of the maxilla: medially, superiorly, and posteriorly at a 45 degree angle to the maxillary occlusal plane. Various complications can result from an improperly placed PSA nerve block. The most common complication is a hematoma resulting from trauma to the pterygoid plexus of veins. Another reported complication, although uncommon, is a temporary Bell’s Palsy if the needle is improperly placed into the parotid bed. Although a short needle is recommended for a PSA injection, many clinicians utilize long needles. In this study, an experienced dentist placed a 25 gauge long needle in the oral cavity of fresh tissue cadavers. A 1.8 ml carpule of 10% methylene blue was then injected into the site. To examine the extravasation of the dye in the tissue, dissections were performed and digital images were taken. We observed that using proper technique, the anesthetic would label the PSA nerve. However, improper placement of the needle could lead to damage of the pterygoid plexus, labeling of the inferior portion of the parotid gland with the cervicofacial division of the facial nerve, and labeling in the lateral or medial pterygoid muscles which would result in trismus.