Submandibular Incision Research Articles

Preliminary Application of Bilateral Submandibular Horizontal Incision in the Treatment of Upper Cervical Tumors.

The upper cervical spine has a complex anatomical structure, making anterior surgical approaches challenging and prone to complications. This study aims to explore the use of bilateral submandibular incisions to provide safer and more convenient exposure of the upper cervical spine and to assess the feasibility of this approach for anterior surgical treatment of complex upper cervical diseases. From November 2019 to August 2021, three patients with malignant tumors of the upper cervical spine were subjected to an anterior-posterior combined approach for cervical tumor resection. The cohort consisted of one male and two females, aged between 41 and 51 years. The anterior approach began with a submandibular incision, followed by blunt dissection through the prevertebral muscles to expose the diseased vertebra. Subsequently, the diseased vertebra was excised, and either a titanium cage or a pre-customized 3D-printed artificial vertebral body was implanted anteriorly. Then, posterior fixation of the cervical spine was performed using pedicle screws to provide additional stability. Follow-up ranged from 8 to 34 months. All patients experienced varying degrees of pain relief within 24 hours post-operation. Frankel grading showed improvement by at least one grade in all three cases. Regular X-ray and magnetic resonance imaging examinations revealed no tumor recurrence or involvement of adjacent vertebrae in the surgical area. The anterior bilateral submandibular horizontal incision approach offers comprehensive exposure of the anatomical structures of the upper cervical spine. This approach introduces a new option for the anterior treatment of upper cervical spine diseases.

A new approach: Cervical approach for marginal resection of the posterior mandible

Gingival squamous cell carcinoma (SCC) of the posterior mandible often requires marginal resection of the mandible in conventional surgery. However, the posterior location of the lesion can limit surgical visibility, which is critical for complete tumor removal and minimizing recurrence. Typically, marginal resection of the posterior mandible is achieved through a midline lower lip incision and mental nerve transection, providing adequate exposure but resulting in nerve damage, lip numbness, and facial scarring. In this paper, we describe a case using a submandibular incision for neck dissection, extending from the mandibular angle to the mental foramen, to fully expose the posterior mandible. The intraoral incision, extending 1 cm beyond the tumor margin, connected with the submandibular incision. Under direct vision, we performed a marginal resection of the mandible, preserving the inferior alveolar neurovascular bundle and the mental nerve, and maintaining at least 1 cm of the inferior mandibular margin. This technique achieved complete tumor removal while preserving mental nerve function and lower lip integrity, reducing surgical difficulty and patient trauma. This approach maintains nerve function and aesthetics as much as possible, with a faster postoperative recovery. In treating gingival SCC of the posterior mandible, it is essential to preserve surrounding healthy tissue and critical anatomical structures, minimizing postoperative complications while ensuring complete tumor resection.

Lymphovenous Anastomosis for the External and Internal Types of Head and Neck Lymphedema: A Case Series and Preliminary Clinical Results.

Head and neck lymphedema (HNL), including external and internal types, could be a possible consequence for patients who have received neck dissection and radiotherapy for head and neck cancer. Initially, the common presentations are heaviness or tightness, followed by swelling in appearance, or difficulty speaking and swallowing in internal edema cases. Lymphovenous anastomosis (LVA) is an established approach to treat extremity lymphedema. We hereby present our preliminary experience in using LVA to treat HNL. Between March 2021 and January 2024, six patients with HNL were treated with LVA via a preauricular or submandibular incision of the obstructed side. Lymphedema Symptom Intensity and Distress Surveys-Head and Neck (LSIDS-H&N) were used for evaluation. In addition, for the external type, MD Anderson Cancer Center Head and Neck Lymphedema (MDACC HNL) rating scale was used for evaluation. For the internal type, Swallowing Quality of Life was used for evaluation. With an average follow-up period of 15.4 ± 15.9 months, LSIDS-H&N improved from 1.11 ± 0.54 to 0.44 ± 0.66 (P = 0.02). For patients with the external type, within an average follow-up period of 15 ± 16.1 months, the MDACC HNL rating scale improved from level 2 to 0 or 1a (P = 0.008). For patients with the internal type, within an average follow-up period of 21 ± 17.3 months, Swallowing Quality of Life improved from 130.5 ± 9.2 to 151 ± 19.8 (P = 0.5). Based on our preliminary results, LVA could be a potential solution to both external and internal HNL.

Arrow shot injury to the oro facial regions: Report of two cases

Background: Arrow injury is a case of foreign body impaction. It can affect any part of the body. Arrow injury to the head and neck region can be life-threatening. An arrow is a weapon consisting of a thin, straight stick with a sharp point, designed to be shot from a bow. It is one of the oldest tools for hunt and war. Many health practitioners especially in the developed world now regard arrows as extinct. It has been completely replaced by advanced modern weaponry. This is not the case in our environment where the use of arrows with their attendant injury is still relatively common.
 Case report: The first case is a 25-year-old farmer, a Nigerian man was seen at the Accident and emergency unit of our centre with an hour history of arrow injury to the right side of the face following the farmer-herder clash. The examination was remarkable for an impacted arrow that was made up iron (impregenation with poisonous substance could not be ascertained) on the right side of the face. He had an urgent plain radiograph of the head and neck which revealed an impacted arrow in the right zygomatic bone. He subsequently had emergency exploration and removal of the arrow. The post-operative period was uneventful.
 The second case was a 37-year-old man who presented to the accident and emergency department with difficulty breathing following an arrow shot injury to the oral cavity. He was a passenger in a bus that was attacked by armed bandits. On examination, there was an arrow penetrating through the right edge of the tongue, the floor of the mouth to the contralateral submandibular and cervical regions. About 5.0cm of the tail of the arrow could be seen jutting out of the mouth. The exploration was done via a Risdon incision (submandibular incision) on the opposite side of the entry wound (left submandibular) in a retrograde approach. The dissection was advanced into the subcutaneous tissue, platysma, and deep fascial plane to expose the tip of the arrow. The post-operative period was uneventful.
 Conclusion: We have illustrated our experience on the cases of arrow injury to the orofacial region. The two cases presented early. There was no pre-hospital attempt at pulling out the arrow. Arrow injury is still common in our community. There is a need for government at all levels to intensify effort on conflict management and resolution.

Misplaced Pterygoid Implant removed following Surgical Exploration

A 62-year-old male patient had reported to our department with a history of pterygoid implant placement in the right maxillary region. The referring dentist had updated us about the possibility of a misplaced implant. The patient was anxious but showed no clinical signs of discomfort or pain. A CT scan with contrast was done to check for the location of the implant and also visualize the proximity to any vital structures. The CT study revealed an implant seen in the right parapharyngeal space closely abutting the internal carotid artery. The screw of the implant was sharp and since it was closely abutting the internal carotid artery it warranted removal at the earliest. An endoscopic approach was discussed with the ENT surgeons but due to the size of the implant and limited access through the antrum we had to look for an alternative method. The technique of performing an access osteotomy of the maxilla would give better visualization and access to the implant but would require the maxilla to be plated and the patient who was 62 years old was not too keen on the thought of this procedure. Finally, an extraoral submandibular approach was finalized and used. Under general anaesthesia, a submandibular incision was marked and dissection was done, the carotid was first identified and taken control off in case we encountered any bleeding or injury to the internal maxillary artery while removing the implant. Dissection continued towards the mandible and the masseter was split to give access to the pterygoid region. An intraoperative C- arm showed that the implant was in close vicinity. The implant was removed intraorally via the buccal vestibule and the wound sites were closed without any complications.

Intraoral versus transcervical approaches in mandibular reconstruction with free flaps: A retrospective study

This study aims to investigate the clinical and functional differences between intraoral and transcervical approaches for segmental mandible resection and reconstruction with free flaps. Patients diagnosed as benign and low-grade mandibular malignant tumors without neck dissections were retrospectively reviewed and divided into intraoral and transcervical groups. Patients of intraoral group underwent intraoral mandibulectomy and vascular anastomosis was performed through a 2-cm submandibular incision, while traditional submandibular approach was used in transcervical group. Clinical characteristics of two groups were assessed including body mass index (BMI), defect types and number of fibular segments, as well as perioperative variables such as operation time, blood loss, drainage volume. The score of appearance, swallowing and speech using the University of Washington Quality of Life Questionnaire (UW-QOL) was recorded and analyzed 6-month postoperatively.A total of 14 patients in intraoral group and 21 patients in transcervical group was collected, respectively. In intraoral group, intraoperative blood loss and postoperative drainage volume were significantly reduced in comparison with transcervical group (p = 0.0146, p = 0.0017; respectively). The score of appearance was 87.50 ± 12.97 in intraoral group, which was significantly higher than 64.29 ± 12.68 in transcervical group (p < 0.0001). Similar results were found in patients of subtype Class II mandibular defect between two groups. However, patients of intraoral group had a significant increase in operative time and a comparable amount of intraoperative blood loss (p = 0.0472, p = 0.1434; respectively).Within the limitations of the study it seems that an intraoral approach combined with a 2-cm submandibular incision should be preferred over a transcervical approach for segmental mandibulectomy and free flap reconstruction whenever appropriate.

A novel pilot animal model for bone augmentation using osseous shell technique for preclinical in vivo studies.

Bone grafting is commonly used to reconstruct skeletal defects in the craniofacial region. Several bone augmentation models have been developed to evaluate bone formation using novel bone substitute materials. The aim of this study was to evaluate a surgical animal model for establishing a three-dimensional (3D) grafting environment in the animal's mandibular ramus for bone augmentation using the osseous shell technique, as in humans. Osteological survey of New Zealand white (NZW) rabbit skull (Oryctolagus cuniculus): Initial osteological and imaging surveys were performed on a postmortem skull for a feasibility assessment of the surgical procedure. Postmortem pilot surgery and cone beam computed tomography imaging: a 3D osseous defect was created in the mandibular ramus through a submandibular incision. The osseous shell plates were stabilized with osteosynthesis fixation screws, and defects were filled with particular bone grafting material. In vivo surgical procedure: surgeries were conducted in four 8-week-old NZW rabbits utilizing two osseous shell materials: xenogeneic human cortical plates and autogenous rabbit cortical plates. The created 3D defects were filled using xenograft and allograft bone grafting materials. The healed defects were evaluated for bone formation after 12 weeks using histological and cone beam computed tomography imaging analysis. Clinical analysis 12 weeks after surgery revealed the stability of the 3D grafted bone augmentation defects using the osseous shell technique. Imaging and histological analyses confirmed the effectiveness of this model in assessing bone formation. The proposed animal model is a promising model with the potential to study various bone grafting materials for augmentation in the mandibular ramus using the osseous shell technique without compromising the health of the animal. The filled defects could be analyzed for osteogenesis, quantification of bone formation, and healing potential using histomorphometric analysis, in addition to 3D morphologic evaluation using radiation imaging.

Use of nanoparticle form of milled teeth as a bone graft substitute in rabbits

Aims of the study: This study was designed to determine the effects of milled tooth in its nanoparticle forms as a bone substitute materials on the acceleration of bone healing in rabbits. Materials and Methods: Sixteen albino rabbits were used in the experiment that were divided into two groups: nanoparticle group (M0 group) and control group. Rabbits were anesthetized using intramuscularly administered 10% ketamine (40mgkg) and 2% xylazine (5mgkg) (Inferchemi, Holland). After shaving and sterilization of the site of the operation, a 2cm submandibular incision was done. Then 3 millimeter circular anterior full-thickness defect was created near the midline of the mandible. The anterior defect was filled with 50-100nm milled tooth material nanoparticles. The incision was sutured with 3/0 black silk. Following surgery, each rabbit was given 30 mg/kg oxytetracycline intramuscularly. The rabbits were euthanized at 3, 7, 14, and 28 days afterwards. Then the specimens were dried and fixed in paraffin before being removed from the skulls. Histological examination the specimens was done.

Applicability of bone landmarks in marking submandibular and subangulomandibular incision lines to ward conservation of the mandibular marginal nerve

Due to its location, the mandibular marginal nerve can be traumatized during various surgeries in the OMF sphere. Its damage rate varies from 1.7% to 50%, depending on several factors. We studied 25 patients with submandibular and subangulomandibular wounds undergoing inpatient treatment in the department of Oro–maxillo–facial Surgery, Institute of Emergency Medicine. The length of the incision and its positioning in relation to the anatomical bone landmarks such as the angle of the mandible and the lower margin of the mandible were examined. The integrity of the mandibular marginal nerve was assessed by checking the functions of the lower lip muscles. Of the 25 patients analyzed in the study, 13 were diagnosed with mandibular marginal nerve damage. The failure rate obtained when demarcating the incision line 2 cm inferior to the lower margin of the mandible is 72% at the mandibular angle and 44% at the anterior margin of the masseter muscle. In conclusion, marking of the submandibular or subangulomandibular incision line cannot be performed predictably using bone anatomical landmarks.

A Modified Submandibular Approach - Assessment of Outcome

The submandibular approach has been an integral tool in facial surgery since 1934. The technique is indicated in different clinical scenarios. This approach is governed by two key determinants; namely the skin tension lines and the course of the marginal mandibular branch. Aim of study: this study suggests that moving the incision further into the neck while respecting the course of the facial nerve would help achieving both optimal esthetic outcome as well as less nerve injuries. Materials and methods: eight patients requiring facial surgery, where the submandibular approach was indicated, were recruited and the modified submandibular incision was applied. The function of the facial nerve was followed up for six months using the Houseman-Brackman test. The esthetic result was assessed by two panels; consultant maxillofacial surgeons, and lay persons mainly concerned with the esthetics. The panel reviewed the cases through a power point presentation. A questionnaire customized to each panel’s expertise was then provided. Results: Surgeons grading intra-class correlation coefficient (ICC) showed that there was an excellent agreement in questions 1, 4, 5 and 7 (ICC=0.672, ICC=0.647, ICC=0.753 and ICC=0.679 respectively). The 5 different maxillofacial surgeons had excellent agreement on that the incision utilized accurately facilitated accessibility, good healing and pleasant esthetic outcome. Regarding lay persons grading, intra-class correlation coefficient (ICC) showed that there was an almost perfect inter-observer agreement on the success of the technique esthetically (ICC=0.826 and 0.838 respectively).Conclusion: the modified submandibular approach provided better aesthetic results and lower risk of facial nerve injury.

Development and clinical application of custom-made temporomandibular joint-skull base combined prosthesis

Objective: To introduce the design, manufacture and clinical application of the custom-made temporomandibular joint (TMJ)-skull base combined prosthesis and evaluate its safety, effectiveness and accuracy. Methods: The patients diagnosed with the TMJ-skull base lesion in Department of Oral Surgery, Shanghai Ninth People's Hospital from October 2016 to November 2020 were recruited in this study. The maxillofacial CT data for all the patients were obtained and transformed into the Mimics 18.0 software preoperatively. The custom-made TMJ-skull base combined prosthesis, included four components, was designed based on the anatomy, stress distribution and movement of the TMJ and skull base, and fabricated by three-dimensional printing and 5-axis milling technologies. The TMJ-skull base lesion was excised completely with the help of digital templates from modified preauricular and/or post and submandibular incisions. The combined prosthesis were implanted and fixed after the lesion resection. The examinations including general situation, cranio-maxillofacial structure and function were taken during and after surgery to assess its using effect. Results: Ten patients [6 females and 4 males, (43.2±13.6) years old] were included and all prostheses were positioned accurately and fixed excellently. After (29.4±17.3) months follow-up, the occlusion relationship was stable and no adverse symptoms such as dizziness, headache, meningeal irritation and permanent facial nerve injury occurred. The pain, diet, mandibular movement function, lateral movement to diseased side and mouth opening had significant improvements. The forward movement and lateral movement to normal side were not improved significantly. There were no prosthesis displacement, loosening and fracture in X-ray and CT postoperatively. With the pre and postoperative craniomaxillofacial model merging, the maximal implanted error was (0.52±0.17) mm for fossa and condyle and (1.62±0.26) mm for skull base and mandibular handle in surface deviation analysis. Conclusions: The custom-made TMJ-skull base combined prosthesis with customized design and 3D printing fabrication is safe, effective and precise in clinical application.

Osteonecrosis of the Jaw in a Crohn's Disease Patient following Infliximab Therapy: A Case Report and Literature Review

Abstract: Introduction: Medication-related osteonecrosis of the jaw (MRONJ) is a serious complication, occurring to patients undergoing treatment with antiresorptive medication, such as bisphosphonates, denosumab or bevacizumab, for different oncologic and non-oncologic diseases. The aim of this study is to report a case of MRONJ in a young patient treated with infliximab, a tumor necrosis factor-a inhibitor used in the treatment of immune-mediated inflammatory diseases such Crohn’s disease, ulcerative colitis, ankylosing spondylitis, rheumatoid and psoriatic arthritis. Case Report: A 27-year-old female patient diagnosed with Crohn’s disease, who had been undergoing intravenous infliximab therapy every seven weeks for 8 years, sought our oral and plastic maxillofacial department with a peri-mandibular abscess for further treatment. The patient underwent surgical treatment, including the extraoral sub-mandibular incision of the abscess and the extraction of the lower second premolar under the administration of intravenous antibiotics. We traced a wound dehiscence and delayed healing procedure of the extraction’s alveolar bone, and five weeks later, the patient returned with an abscess recurrence around the mandibular angle area. The patient underwent surgical treatment with wide bone resection and debridement of the necrotic tissues. After follow-up (4 months), the patient completely healed without signs of recurrence. Discussion: Osteomyelitis of the jaw by patients treated with infliximab has been sparsely described in publications. This case confirms the potential role of infliximab in the pathogenesis of MRONJ. Since the pathomechanism of MRONJ under infliximab therapy remains unclear, we recommend a regular oral check-up before starting therapy, as well as during the therapy with infliximab, in order to possibly prevent the MRONJ onset. Keywords: Medication-Related Osteonecrosis of the Jaw, Infliximab, TNF-a Inhibitors, Crohn’s Disease and Osteomyelitis.

Conventional skin suture, skin staple versus contemporary tissue adhesive for maxillofacial elective wound care—A single blind prospective randomized comparative study

IntroductionThere are numerous dependable techniques of wound closure, employing a wide range of materials. The proposed hypothesis for this single blind prospective randomized comparative study is tissue adhesive has better clinical outcome in terms of time taken, inflammatory changes, complications, esthetic outcome and cost efficacy for surgical wound closure of standardized submandibular incisions with sutures and staples. MethodsPatients from either gender in the age group of 15–40 years, undergoing closure of submandibular incision were randomly allocated to three group i.e tissue adhesive, suture and staples groups respectively. Following surgical intervention patients were then followed up for a period of 4 months. Wounds were evaluated by two independent investigators on 7th, 14th, 30th, 60th, 90th and 120th post-operative day. The parameters measured were time consumption for closure during surgery, quality of wound healing and cosmesis during follow up. Results42 patients, 14 in each group were treated in the present study. A statistically significant time efficiency was noted in the staple group (64.5 ± 21.4 s, p < 0.001) as compared to the others. However in terms of cosmesis, suture group outstands the other with a statistical significance of P1 = 0.009, P2 = 0.029. No significant difference was observed among the groups in terms of inflammatory changes and complications. ConclusionThe hypothesis was thus rejected as tissue adhesive has no significant clinical outcome in submandibular incision. The result of the present study demonstrate that skin closure by suture may increase the duration of surgery but wound cosmesis was better and face being an esthetic area, cosmetic outcome is paramount.

Submandibular approach for tracheal intubation of maxillofacial fracture patient

Introduction: Airway management of facial trauma patients remains a challenge for anaesthesiologists. Alternatives are needed for patients who are unable to perform the nasotracheal or orotracheal intubation commonly used in general anaesthesia for dental surgery. However, if prolonged maintenance of airway or ventilation is not needed, tracheostomy is not an appropriate alternative. Objectives/Aims: We report a case of submandibular intubation using sterile disposable camera cable drape (Sani-sleeve®) to minimise the injury caused by surgical intubation. CASE REPORT: The patient was diagnosed with LeFort II fracture (both), LeFort III fracture (Lt.), Infraorbital wall fracture, maxillary anterior alveolar fracture, maxillary sinus anterior wall fracture, and lower lip laceration due to facial trauma. The nasotracheal and orotracheal intubation were impossible. Therefore, we decided to perform submandibular intubation to reduce the sequelae of invasive tracheostomy. Then awake fibreoptic orotracheal intubation was performed successfully with 7.5 mm sized reinforced tube. After confirming the success of orotracheal intubation, submandibular approach for tracheal intubation was started. Submandibular incision (2 cm) was performed on two fingers away from the right mandibular border. We made a tunnel by blunt dissection with Kelly forceps and dissecting scissors to right oral cavity floor. The Sani-sleeve® (Camera cable drape) was passed with Kelly forceps through a tunnel from extraoral to intraoral space. Another 7.5 mm sized reinforce tube was passed into the Sani-sleeve® to dilate the space which the intubated tube would pass. After confirming that space was created, the intubated tube was repositioned to extraoral space through the Sani-sleeve® tunnel and fixed. At the end of the surgery, the submandibular intubated tube was repositioned again to the oral cavity. Conclusion: This case suggests that submental or submandibular intubation can be an appropriate alternative to the tracheostomy.

Total temporomandibular joint replacement without a submandibular incision

Temporomandibular joint replacement is a well-accepted and successful treatment option for advanced pathology of the temporomandibular joint. There are however a number of complications associated with the procedure such as post-operative infection, facial nerve damage and scarring. Total joint replacement has traditionally involved the use of both a pre-auricular and submandibular incision. We present an approach that uses only a pre-auricular incision without the need for a submandibular incision. This approach is less invasive and has the potential to decrease risk of damage to the marginal mandibular branch of facial nerve and scarring of the neck.

MONOSTOTIC FIBROUS DYSPLASIA: CASE REPORT

In fibrous dysplasia, abnormal proliferation of fibroblasts and differentiation of osteoblasts occurs, resulting in a defect of bone marrow replacement by a fibrous connective tissue. The case report refers to a 54-year-old patient with complaints of facial asymmetry who in the intraoral palpation presented painless, immotile swelling with normal bone consistency and mucosal staining. Radiograph revealed radiolucent unilocular lesion associated with diffuse radiopacities and poorly defined margins. The patient underwent surgery for excisional biopsy under general anesthesia. Surgical access was extraoral through submandibular incision and, for localization of the lesion, ostectomy was performed on the mandibular branch with piezo motor. After locating the lesion, curettage and removal of fibrous tissue associated with calcifications were performed. Despite the close proximity with the inferior alveolar nerve, the patient did not present hyperalgia or related paresthesia. The histopathologic report was compatible with fibrous dysplasia. In fibrous dysplasia, abnormal proliferation of fibroblasts and differentiation of osteoblasts occurs, resulting in a defect of bone marrow replacement by a fibrous connective tissue. The case report refers to a 54-year-old patient with complaints of facial asymmetry who in the intraoral palpation presented painless, immotile swelling with normal bone consistency and mucosal staining. Radiograph revealed radiolucent unilocular lesion associated with diffuse radiopacities and poorly defined margins. The patient underwent surgery for excisional biopsy under general anesthesia. Surgical access was extraoral through submandibular incision and, for localization of the lesion, ostectomy was performed on the mandibular branch with piezo motor. After locating the lesion, curettage and removal of fibrous tissue associated with calcifications were performed. Despite the close proximity with the inferior alveolar nerve, the patient did not present hyperalgia or related paresthesia. The histopathologic report was compatible with fibrous dysplasia.

Parapharyngeal Hemangiopericytoma: the Role for Mandibular Proximal Segment Replantation-Review of Literature.

Pharyngeal hemangiopericytoma is a rare tumor .Surgical access to space has been selected based on the location of the tumor in this space, size, and type of pathology. Hemangiopericytoma requires extracapsular dissection. Hemorrhagic nature and tight attachment to adjacent tissues are the other reasons for choosing the surgical approach with the best access. The patient was a 55-year-old female with left-sided facial swelling and dumbbell-shaped lesion involving buccal and lateral pharyngeal space. Brisk hemorrhage happened during biopsy. Submandibular incision, osteotomy of mandibular angle, and temporary proximal segment removal were done. Extracapsular dissection of the lesion performed under direct vision. Proximal segment was returned to the original location and internally fixed with miniplate. Postoperative course was without complication. Mandibular proximal segment replantation technique should be used to treat parapharyngeal tumors with a hemorrhagic tendency.

Advanced Model of a 4-Step Chart for Percutaneous Approaches to Condylar Fractures: A Tool to Comprehend Trends in Classification Based on the Dissection Route

In the application of percutaneous approaches for mandibular condyle fractures, facial nerve injury (FNI) has been the most troubling aspect associated with surgical repair.1 The conventional classification of these approaches according to the incision site does not reflect the risk of FNI owing to diverse dissection routes via a similar incision,2 which have confused surgeons and residents who intend to minimize the morbidity.3 Equivocal examples in the treatment of condylar neck and subcondylar fractures include approaches via retromandibular incisions (transparotid, retroparotid, and transmasseteric anteroparotid [TMAP] approaches), as well as those via submandibular incisions (traditional submandibular [Risdon] and high perimandibular [high cervical TMAP] approaches).

Surgical anatomy of ovine facial and hypoglossal nerves for facial nerve reconstruction and regeneration research: An experimental study in sheep

The lack of a clinically relevant animal model for facial nerve research is a challenge. The goal of this study was to investigate the anatomy of the ovine facial and hypoglossal nerves to establish a clinically relevant facial nerve research model. Six cadaver female Merino sheep (33.5 ± 3 kg, approximately 3 years old) and three anesthetized female Merino sheep (30 ± 3 kg, approximately 3 years old) were used. In cadaver sheep, a right side preauricular to submandibular incision was made. Dimensions of the face, neck, and length of facial nerve were measured. In anesthetized sheep, each facial nerve branch and hypoglossal nerve in the right side was stimulated. The number of myelinated fibers was analyzed histologically. The facial nerve exited the stylomastoid foramen and divided into upper and lower branches. The lower branch then subdivided into buccal and marginal mandibular branches. The hypoglossal nerve was observed behind the digastric posterior belly. Stimulation revealed the temporal, zygomatic, buccal, marginal mandibular, and cervical branch innervated the forehead, orbicularis, upper lip and nasal, lower lip, and platysma, respectively. The number of myelinated fibers of the main trunk, upper, buccal, lower branch, and hypoglossal nerve was 11 350 ± 1851, 4766 ± 1000, 5107 ± 218, 3159 ± 450, and 7604 ± 636, respectively. The length of the main trunk was 9.2 ± 1.5 mm, and distance of the marginal mandibular branch to the facial artery was 94 ± 6.8 mm. Due to the similarity in nerve anatomy and innervation, the ovine model can be used as a clinically relevant and suitable model for facial nerve research.

The effects of two bone substitute materials in the treatment of experimentally induced mandibular defects: An experimental study

Aims: To compare between the effects of deproteinized bovine bone (DBB) and osteon in the healing of mandibular bone defects in the rabbits. Materials and Methods: This experimental study was conducted on ten rabbits at the Animal House, Dentistry college, Mosul University. The rabbits weighted between 1.5 and 2 kg and each rabbit was given anesthesia (10% ketamine (40 mg/kg) and 2% xylazine (5 mg/kg). Surgery was performed aseptically. Mandibles were exposed through a sub-mandibular incisions. Three rectangular full thickness defects (6×5 mm) were created in each side. The first defect in each side was filled with DBB, the second defect was filled with osteon, while the third defect was left untreated to serve as a control. Five rabbits were sacrificed after one week and the other five rabbits were sacrificed after one month. The bony mandibles were immersed in 10% formalin solution and examined histologically by two histopathologists. Results: Microscopically, sections for one week of all groups showed mild degree of inflammation, moderate amount of vascularity, granulation tissue and osteoid tissue formation. Sections of one month showed no difference regarding the degree of inflammation vascularity, but the amount of granulation tissue and osteoid tissue formation in the control group were lesser than the amount seen in both experimental groups. Conclusions: DBB and osteon accelerate bone healing after month regarding the amount of granulation tissue and osteoid tissue formation.