A new space of the face: The bucco-mandibular space

Anatomy of the Buccal Space: Surgical and Radiological Perspectives

Among the anatomical spaces in the head and neck area, the buccal space has often been studied in dental/oral surgery and cosmetic surgery because it contains the facial vessels, mandibular and facial nerves, and adipose tissue called the buccal fat pad. In addition, as the space can communicate with other spaces, it can be significant in infections. Although the anatomy of the buccal space has been reported in several studies, there have been discrepancies concerning its boundaries, and its communications have often been overlooked. The aim of this review is to examine the anatomy of buccal space including its boundaries, contents, continuity with adjacent spaces, and clinical significance. A literature review was performed on Google Scholar and PubMed. The literature has depicted the anterior, medial, and lateral boundaries more or less consistently, but descriptions of the posterior, superior, and inferior borders are controversial. The buccal space includes the facial arteries, veins, facial nerves, parotid duct, and lymph nodes, which can be described differently depending on definitions and the extent of the space. As it communicates with other anatomical spaces including the masticatory space, it can be a reservoir and a channel for infections and tumors. Buccal fat pads have various clinical applications, from a candidate for flap reconstruction to a target for removal for cosmetic purposes. This review will help understand the anatomy of the buccal space including its boundaries, residing structures, and communication with other spaces from surgical and radiological perspectives.

New anatomical findings in the mandibular body region: Two parts that make up bucco-mandibular space

Soft tissue spaces not only enable gliding by contraction of the facial muscles, but they also cause drooping of the superficial fat due to gravity in the upright position. This study was performed to clarify the structures around the bucco-mandibular space (BMS) and to apply this anatomical knowledge to clinical practice. Four sides of the face were dissected using a conventional gross anatomical dissection technique, and 10 sides (5 horizontal and 5 frontal sections) of the removed semi-facial soft tissue were dissected using the stretched tissue dissection (STD) method. Histological examination of the mandible was performed on two sides to confirm the findings of conventional gross anatomical dissection and STD. In all cases, both gross dissection and STD revealed that the BMS was composed of two parts. The superficial part was filled with adipose tissue containing nerves and vessels, including the marginal mandibular branch of the facial nerve, facial artery, facial vein, and mental nerve. We named this part the adipo-neuromandibular part. By contrast, the deep part was separated from the adipo-neurovascular part by facial deep fascia and composed of loose connective tissue. We named this deep part the loose connective tissue part. The STD method enabled us to obtain detailed anatomical findings of the mandibular region and elucidate two parts of the BMS in which the neurovasculature is distributed. We believe that these findings provide new insights into facial anatomy by resolving existing anatomical uncertainties and will contribute to safer surgical treatment in the facial region.

Invasion of the bucco-mandibular space by oral squamous cell carcinoma: histopathological analysis of invasion pattern

Background

This study aimed to determine the patterns of invasion of oral squamous cell carcinoma (OSCC) into the bucco-mandibular space (BMS) using detailed histopathological analysis and to assess clinical outcomes.

Methods

Patients with OSCC who underwent segmental mandibulectomy or hemi-mandibulectomy combined with resection of the BMS between 2012 and 2021 were included. The invasions of the BMS were classified into three patterns. Pattern A was defined as a horizontal invasion, Pattern B as a vertical invasion, and Pattern C as an expansive invasion.

Results

In total, 109 patients were reviewed. Of these 109 patients, the primary tumor affected the lower gingiva in 78 patients, the buccal mucosa in 18 patients, and was a primary intraosseous carcinoma of the mandible in 13 patients. Invasion of the BMS was significantly associated with a higher pathological T stage, positive/close margins, and lower disease-free survival (DFS) rates. The DFS rates were 86.7% and 66.0% in the BMS non-invasion and invasion groups, respectively. The DFS rates for each type of invasion were 82.1% for Pattern A, 67.4% for Pattern B, and 48.0% for Pattern C (P=0.277).

Conclusion

Patients with BMS invasion have a poorer prognosis than those without invasion of the BMS. Therefore, adjuvant therapy is necessary, especially in Patterns B and C. Evaluation of preoperative BMS invasion patterns is important for predicting the prognosis of OSCC.

Anesthetic efficacy of buffered 4% articaine for mandibular first molar infiltration: a crossover clinical trial

Background

The limited studies on the effect of buffering on the clinical efficacy of articaine have reported controversial results. The purpose of this study was to clinically compare the pain of injection, anesthetic success, onset, and duration of pulpal anesthesia of buffered 4% articaine with epinephrine 1:100000 versus a non-buffered 4% articaine with epinephrine 1:100000 formulation for buccal infiltration of the mandibular first molar.

Methods

Sixty-three volunteers were enrolled in the study. All volunteers received two injections consisting of a single mandibular first molar buccal infiltration with 1.8 ml of 4% articaine with epinephrine 1:100000 and 1.8 ml of 4% articaine with epinephrine 1:100000 buffered with 8.4% sodium bicarbonate. The infiltrations were applied in two separate appointments spaced at least one week apart. After injection of the anesthetic solution at the examined site, the first molar was pulp-tested every 2 min for the next 60 min.

Results

Successful pulpal anesthesia was recorded in 69.8% of cases using non-buffered articaine solution and 76.2% of cases using buffered articaine solution, with no significant difference between the formulations (P = 0.219). The mean time of anesthesia onset for the volunteers with successful anesthetic outcome in both formulations (n = 43) was 6.6 ± 1.6 min for the non-buffered articaine solution and 4.5 ± 1.6 min for the buffered solution, which differed significantly (P = 0.001). In the same volunteers, the mean duration of pulpal anesthesia was 28.4 ± 7.1 min for non-buffered articaine solution and 30.2 ± 8.5 min for buffered articaine solution, with no significant difference between the formulations (P = 0.231). Considering the pain of injection, regardless of the anesthetic success, the mean values of VAS were 11.3 ± 8.2 mm for the non-buffered articaine solution and 7.8 ±6.5 mm for the buffered articaine solution, which differed significantly (P = 0.001 < 0.05).

Conclusion

According to the present study, 4% articaine with epinephrine can benefit from buffering and provide better anesthetic behavior, with improved onset and less pain during injection.

The mental artery: anatomical study and literature review

The mental artery is a terminal branch of the inferior alveolar artery arising from the maxillary artery. It often communicates with the submental and inferior labial arteries branching off the facial artery. To our knowledge, few reports have described its anatomy and clinical significance in detail. The aim of this paper was to clarify the anatomy of the mental artery. Ten sides from five embalmed Caucasian cadaveric heads were used. The facial artery was identified at the point passing through a notch for the facial vessels and was traced medially. The mental artery and its anastomoses with other arteries were observed in detail. It was detected on all sides. Fourteen anastomoses were found, eight with the inferior labial artery and six with the submental artery. On one side, the mental artery directly supplied the lower lip with no anastomosis. The inferior labial artery tended to anastomose with the mental artery superior to the mental foramen and was likely to anastomose with the submental artery anterior to the mental foramen. We clarified the detailed anatomy of the mental artery. Our results could provide dentists with information that will help them to make oral surgery safer and more successful.

A new treatment for lingual nerve injury: an anatomical feasibility study for using a buccal nerve pedicle graft

PURPOSE

Lingual nerve (LN) palsy is a serious complication in dentistry and repaired by direct suture or a free graft technique. To our knowledge, there has been no study using a (long) buccal nerve (BN) graft as a donor for LN repair. Therefore, we aimed to clarify the location of the BN and investigate if it is feasible to reroute the BN to the LN.

METHODS

Twenty-four sides from 12 fresh-frozen Caucasian cadaveric heads were used in this study. The mean age at death was 73.9 ± 13.4 years. The LN was dissected on the floor of the oral cavity medial to the third molar tooth. Next, the mucosa with the buccinator muscle, pterygomandibular raphe, and superior pharyngeal constrictor muscle on the retromolar area was retracted anteriorly to widen the pathway of the LN. Finally, the BN was cut and transposed to the LN through this widened pathway to its feasibility.

RESULTS

The mean diameter of the BN and vertical distance from the horizontal part of the retromolar trigone to the BN was 1.47 ± 0.32 mm and 18.53 ± 6.21 mm, respectively. On all sides, the BN was able to be transposed to the LN without tension.

CONCLUSION

Such a technique might be used for the patients with LN injury and who have lost sensation of the tongue.

The Great Auricular Nerve: Anatomical Study with Application to Nerve Grafting Procedures

BACKGROUND

When it comes to autogenous nerve grafting, the sural and great auricular nerve (GAN) are the 2 nerves predominately used for trigeminal and facial nerve repair. Arising from the second and third cervical ventral rami, the GAN emerges from the posterior border of the sternocleidomastoid coursing superiorly and anteriorly toward the ear.

METHODS

Eleven sides from 5 Caucasian and 1 Asian cadaveric heads (all fresh-frozen) were used. One man and 5 women were used with an age at death ranging from 57 to 91 years, with a mean of 80.3 years. Measurements were made from the inferior border of the ear to the GAN, the GAN to the external jugular vein, and the inferior border of the mastoid process to the GAN; the proximal, medial, and distal diameters of the GAN and the length of the GAN that was obtained from this exposure were also measured.

RESULTS

The mean distance from the inferior border of the mastoid process to the GAN, inferior border of the ear to the GAN, and GAN to the external jugular vein was 27.71, 31.03, and 13.28 mm, respectively. The mean length of the GAN was 74.86 mm. The mean diameter of its distal, middle, and proximal portions was 1.51, 1.38, and 1.58 mm, respectively.

CONCLUSIONS

The GAN is an excellent option for use in nerve grafting for repair of, for example, facial dysfunction. In this study, we review our measurements, techniques for identification, and dissecting techniques for the GAN. The proximity to the operative area and minimal complications associated with GAN grafting might contribute to improved patient satisfaction and better outcomes regarding functional restoration.

Intraoral Dissection of the Mimetic Muscles: Application to Dentistry and Oral Surgery

Mimetic muscles contract and pull the overlying skin toward the muscle’s bony attachment. Numerous books and articles have shown the mimetic muscles via cadaveric dissection. However, for dentistry and oral surgery, the mimetic muscles have not been detailed from intraoral dissection. Recently, several papers have addressed various mimetic muscles in relation to intraoral dissection. However, to our knowledge, there has been no overview of these muscles beneath the oral mucosa. Here, we review the literature concerning the mimetic muscles as revealed during intraoral dissection, create novel illustrations, and discuss the relationship of these muscles with general dentistry and oral surgery. The mimetic muscles, which constitute the surface of the oral mucosa, the relationship of the labial and buccal frenulum and mimetic muscles, the relationship of the mucogingival junction and mimetic muscles, and other surgical procedures are discussed. A better understanding of the mimetic muscles from an intraoral perspective is important for those performing oral surgery and dentistry.