Intraoral Approach for Mandibular Resection with TMJ Disarticulation: Outcomes from a Case Series

ABSTRACT

Objective:  To describe the tactical alterations that allow the use of the intraoral approach for resection of mandibular tumors requiring TMJ disarticulation.

Material and Methods:  Six patients with extensive mandibular lesions requiring temporomandibular joint disarticulation were treated using an intraoral surgical approach. This case series, describes step by step, the intraoral approach for resection of a mandibular tumor with unilateral temporomandibular joint disarticulation. The incision should be made in the vestibular and lingual mucosa and in an anatomical region that guides mucoperiosteal detachment for adequate lesion exposure. An anterior osteotomy enables segment rotation for lingual region access. Segmentation in the retromolar region and coronoidectomy can facilitate disarticulation and allow tumor removal in two stages in extensive lesions crossing the mandibular midline.

Results:  The intraoral approach provides adequate visualization and facilitates TMJ disarticulation while preserving facial aesthetics and soft tissue integrity. Compared with extraoral access, this method minimizes visible scars and preserves recipient-site vascularization, which is essential for graft survival in mandibular reconstructions.

Conclusion:  This technique is described to guide intraoral mandibular tumor resections, aiming to reduce aesthetic alterations, decrease morbidity, mitigate the chances of injury to the marginal mandibular nerve, and ensure greater vascularization of the region.

Keywords:
Surgical Wound; Mandibular Neoplasms; Disarticulation; Surgical Procedures; Operative.

Introduction

Mandibular resections are frequently used in the treatment of tumors of the head and neck. It is an ablative procedure that aims to control the disease and limit the possibility of recurrence [¹]. This type of treatment is indicated for lesions with more aggressive biological behavior and directly affects patients' quality of life. In cases involving the condylar process, mandibular resection with temporomandibular joint (TMJ) disarticulation is recommended [²].

The intraoral approach to mandibular resection has traditionally been used for the treatment of smaller, localized tumors in the anterior region of the mandible. However, some tactical alterations can enable its application in the resection of larger tumors extending into the mandibular ramus and condyle, even when disarticulation is necessary. This technique reduces morbidity at the recipient site, facilitates anastomoses during reconstruction with immediate or delayed microvascularized grafts by preserving cervical anatomy during access, and avoids visible scars [³,⁴]. The purpose is to describe the tactical alterations that allow the use of the intraoral approach for resection of mandibular tumors requiring TMJ disarticulation.

Material and Methods

Ethical Clearance

The study complied with Resolution 466/2012 of the National Health Council. The participants were informed about the objectives, risks, benefits, and protective measures. They consented through an Informed Consent Form (ICF) with assurances of anonymity, confidentiality, and the right to withdraw at any time without affecting treatment. Authorization was granted for the use of clinical, laboratory, and imaging data. The project was approved (approval no. 6.341.143/2023).

Case Series

Case 1

A 36-year-old male patient, with no comorbidities, who denies any habits or addictions, was referred to the Oral and Maxillofacial Surgery and Traumatology department in May 2023 with a complaint of facial swelling on the left side (Figure 1). The patient reported a slow growth history over approximately 8 years, with occasional pain and no paresthesia.

Figure 1
Case 1. A - Frontal view in preoperative; B - Preoperative tomographic reconstruction in frontal view; C - Frontal view in 3-year postoperative; D - Postoperative tomographic reconstruction in frontal view. E - Preoperative intraoral view; F - Intraoral view in 3-year postoperative; G - Incision in vestibular and lingual alveolar mucosa; H - Osteotomy in anterior mandibular region; I - Lateralization of the segment to be resected for access to the lingual region; J - Disarticulation of the temporomandibular joint by digital method; K - Surgical specimen after resection: initially removing the anterior region up to the retromolar trigone region, and finally, after coronoidectomy, the resection of the mandibular ramus and condyle; L - Installation of the reconstruction plate with a PMMA prosthesis previously adapted to the plate and suspension of the suprahyoid musculature. M - Intraoperative radiograph for confirmation of free margins; N - 3D prototype used for PMMA condyle fabrication and preoperative plate modeling; O - Postoperative tomographic reconstruction in lateral view.

On extraoral physical examination, there was observed swelling in the buccal, submental, and submandibular regions on the left side, extending into the cervical IA, IB, II, and IV levels on the left. The intraoral physical examination revealed the presence of purulent drainage and mobility in all teeth involved in the lesion, as well as loss of vestibular depth in the anterior and posterior left regions, lingual cortical expansion, and elevation of the tongue. The overlying mucosa appeared normal in color, with increased vascularity in the swollen area.

Imaging examination using computed tomography of the face processed with Dolphin Imaging (11.95 Premium) revealed an extensive multilocular osteolytic lesion, expansively extending from the region of the lower right first premolar to the left mandibular condylar neck. The lesion showed swelling of the vestibular and lingual cortices and bone fenestrations, measuring approximately 9.30 cm in its largest vestibulo-lingual diameter on the sagittal section, 11.98 cm in its largest mesio-distal diameter on the axial section, 6.97 cm in its largest infero-superior diameter on the coronal section, and a volume of approximately 234.19 cm³.

A previous incisional biopsy was performed at another institution with a preliminary diagnosis of conventional ameloblastoma in August 2022. With laboratory tests within normal ranges, the chosen surgical approach was mandibular resection with condylar disarticulation, with safety margins, accessed via the intraoral route under general anesthesia. This was followed by immediate reconstruction using a 2.4 mm plate system combined with a mandibular condyle prosthesis made of polymethylmethacrylate (PMMA).

Case 2

A 27-year-old female patient with melanin pigmentation, denying any habits or addictions, presented to the Oral and Maxillofacial Surgery and Traumatology department in 2020. She reported spontaneous pain during mastication in the retromolar region on the left side and noted swelling in the left hemiface, with a history of abrupt tumor growth over the past 3 years and worsening pain.

On extraoral physical examination, facial asymmetry and swelling in the left hemiface were observed, with a hard consistency upon palpation and no limitation of mouth opening. There was no cervical lymphadenopathy present. On intraoral physical examination, bulging of the vestibular and lingual cortical plates of the left mandibular body and ascending ramus was identified, with no dental displacement and a firm consistency to the touch.

The facial computed tomography revealed an extensive multilocular mixed lesion with areas of more calcified trabecular bone. The lesion extended from the left condylar neck, sigmoid notch, and coronoid process to the distal region of the lower left first molar, exhibiting bone fenestration and expansion of the vestibular and lingual cortical plates. The lesion measured approximately 6.30 cm in height, 2.65 cm in width, and 4.39 cm in depth at its greatest extent.

An incisional biopsy under general anesthesia was proposed for definitive diagnosis of the lesion, which histopathological examination identified as a central giant cell lesion. A radical surgical approach was proposed. This involved mandibular resection with unilateral temporomandibular joint disarticulation and immediate reconstruction using a 2.4 mm plate system combined with a left mandibular condyle prosthesis made of PMMA, performed via an intraoral approach (Figure 2).

Figure 2
Case 2. A - Frontal view in preoperative; B - Preoperative tomographic reconstruction in frontal view; C - Frontal view in 3-year postoperative; D - Postoperative tomographic reconstruction in frontal view. E - Preoperative intraoral view; F - Intraoral view in 3-years postoperative; G - Incision in vestibular and lingual alveolar mucosa; H - Osteotomy in anterior mandibular region; I - Lateralization of the segment to be resected for access to the lingual region; J - Disarticulation of the temporomandibular joint; K - Surgical specimen after resection; L - Installation of the reconstruction plate with previously adapted PMMA prosthesis to the plate; M - Panoramic reconstruction 3-years postoperative; N - Postoperative tomographic reconstruction in lateral view.

Case 3

A 22-year-old male patient, leucodermic, presented to the Oral and Maxillofacial Surgery service in 2017 with a history of a radiographic finding of a multilocular lesion in the left mandibular body and ramus, discovered after a sports-related trauma.

On extraoral physical examination, a slight swelling was observed in the left mandibular angle. Intraoral clinical examination revealed a discrete obliteration of the left posterior vestibular sulcus, with a mixed consistency. Computed tomography of the face demonstrated an extensive multilocular osteolytic lesion extending from the left mandibular body to the ipsilateral condylar neck, associated with an impacted mandibular third molar.

The patient underwent an incisional biopsy, and the histopathological diagnosis confirmed a conventional ameloblastoma. The treatment of choice was resection with condylar disarticulation. The resection margin was established between the left mandibular first and second premolars, ensuring safe surgical margins. An intraoral incision was performed from the mental region to the left mandibular vestibular sulcus, positioned below the attached gingiva. Following mucoperiosteal flap elevation on the buccal and lingual aspects, osteotomy was carried out, and subsequently, a 2.4 mm locking reconstruction plate was placed together with a prefabricated PMMA condylar prosthesis (Figure 3).

Figure 3
Case 3. A - Frontal view in preoperative; B - Preoperative tomographic reconstruction in lateral view; C - Frontal view in 4-years postoperative; D - Postoperative tomographic reconstruction in lateral view; E - Preoperative intraoral view; F - Panoramic reconstruction pretoperative; G - 3D prototype used for PMMA condyle fabrication and preoperative plate modeling; H - Installation of the reconstruction plate with previously adapted PMMA prosthesis to the plate; I - Surgical specimen after resection; J - Panoramic reconstruction 4-years postoperative; K - Postoperative tomographic reconstruction in axial view.

Case 4

A 16-year-old female patient, melanodermic, with a history of facial swelling evolving over approximately 9 years, presented to the Oral and Maxillofacial Surgery service in 2019 with a previous diagnosis of ossifying fibroma. Clinically, intraoral examination revealed obliteration of the right mandibular vestibular sulcus, associated with tooth mobility and bulging in the right submandibular region, evident in frontal and caudo-cranial views. Imaging examination demonstrated hypodense areas with cortical bone expansion, without fenestration.

The surgical approach was performed through an intraoral access, followed by placement of an Erich arch bar for intraoperative maxillomandibular fixation. Mucoperiosteal flaps were elevated on both buccal and lingual aspects, and digital dissection was carried out for condylar disarticulation. Resection was performed with safe margins at the mesial aspect of the right mandibular second premolar, and a precontoured 2.4 mm locking reconstruction plate was installed together with a prefabricated PMMA condylar prosthesis (Figure 4).

Figure 4
Case 4. A - Frontal view in preoperative; B - Preoperative tomographic reconstruction in frontal view; C - Preoperative tomographic reconstruction in axial view; D - Frontal view in 2-year postoperative; E - Postoperative tomographic reconstruction in frontal view; F - Postoperative tomographic reconstruction in axial view; G - Panoramic reconstruction pretoperative; H - Panoramic reconstruction 2-years postoperative; I - Preoperative intraoral view; J - Intraoral view in 2-year postoperative; K - Surgical specimen after resection; L - Installation of the reconstruction plate with previously adapted PMMA prosthesis to the plate; M - Postoperative tomographic reconstruction in lateral view.

Case 5

A leucodermic patient was referred to the Oral and Maxillofacial Surgery service following a radiographic finding. The patient reported noticing a "lump" near the right mandibular molars in 2020 and observed tooth mobility. Extraction of the right mandibular second molar was performed, followed by an incisional biopsy, which revealed a histopathological diagnosis of conventional ameloblastoma.

On extraoral examination, a discrete swelling was observed in the right mandibular region. Intraoral examination revealed obliteration of the right posterior vestibular sulcus with thickening toward the lingual region posterior to the right mandibular first molar, associated with tooth mobility. Imaging examination demonstrated a multilocular mixed radiolucent lesion extending from the right mandibular body to the sigmoid notch, measuring 54.8 mm superoinferiorly, 31.3 mm buccolingually, and 39.6 mm mesiodistally.

Due to the lesion’s size and extent, resection with unilateral disarticulation of the right temporomandibular joint was indicated, followed by installation of a reconstruction plate with a PMMA condylar prosthesis. The surgical approach was performed through an intraoral access. An intraoral incision was made, with mucoperiosteal flap elevation on both buccal and lingual aspects. Resection was performed with safe margins at the mesial aspect of the right mandibular second premolar, followed by maxillomandibular fixation and placement of a 2.4 mm locking reconstruction plate together with a prefabricated PMMA condylar prosthesis (Figure 5).

Figure 5
Case 5. A - Frontal view in preoperative; B - Preoperative tomographic reconstruction in frontal view; C - Preoperative tomographic reconstruction in lateral view; D - Frontal view in 1-year postoperative; E - Postoperative tomographic reconstruction in frontal view; F - Postoperative tomographic reconstruction in axial view; G - Preoperative intraoral view; H - Osteotomy at the mesial aspect of the right mandibular first premolar; I - Surgical specimen after resection; J - Intraoperative radiograph for confirmation of free margins; K - Maxillomandibular fixation following resection with unilateral TMJ disarticulation and fixation using a 2.4 system plate with PMMA condylar prosthesis. L - Panoramic reconstruction 1-year postoperatively; M - Intraoral view 1-year postoperatively.

Case 6

A leucodermic male patient was diagnosed with a lesion involving the right mandibular angle and ramus, identified on radiographic examination, which revealed an extensive radiolucent lesion in this region. On extraoral examination, a discrete swelling was observed in the right mandibular angle. Intraoral examination revealed obliteration of the right posterior vestibular sulcus and thickening in the ipsilateral retromolar trigone region, in addition to mobility of the right mandibular second molar. Computed tomography demonstrated a multilocular mixed lesion extending from the right mandibular angle to the right condyle, measuring 30.2 mm in the superoinferior dimension, 14.6 mm in the buccolingual dimension, and 29.8 mm in the mesiodistal dimension.

The patient underwent an incisional biopsy, and the histopathological diagnosis confirmed a central giant cell lesion. Due to the size and extent of the lesion, resection with unilateral disarticulation of the right temporomandibular joint was indicated, followed by placement of a reconstruction plate with a prefabricated PMMA condylar prosthesis. The surgical approach was performed through an intraoral access, with mucoperiosteal flap elevation on the buccal and lingual aspects, resection with safe margins at the mesial aspect of the right mandibular second molar, maxillomandibular fixation, and placement of a 2.4 mm locking reconstruction plate together with the prefabricated PMMA condylar prosthesis (Figure 6).

Figure 6
Case 6. A - Frontal view in preoperative; B - Preoperative tomographic reconstruction in frontal view; C - Preoperative tomographic reconstruction in axial view; D - Frontal view in 1-year postoperative; E - Postoperative tomographic reconstruction in frontal view; F - Postoperative tomographic reconstruction in axial view; G - 3D prototype used for PMMA condyle fabrication and preoperative plate modeling; H - Intraoperative radiograph for confirmation of free margins; I - Panoramic reconstruction 1-year postoperative; J - Postoperative tomographic reconstruction in lateral view.

In all reported cases, patients underwent the same surgical technique, consisting of an intraoral approach followed by reconstruction using 2.4-mm system plates pre-shaped from 3D resin prototypes manufactured from each patient's computed tomography (CT) imaging, in association with a PMMA condylar prosthesis. The prosthetic condyles were customized to the morphology and biomechanics of the affected joint, requiring no additional fixation to achieve proper seating in the glenoid fossa. No displacement was observed during follow-up.

Description of the Technique

Intraoral surgical approach is intended for resections of benign mandibular tumors with temporomandibular joint impairment. The step-by-step is described as follows:

Step 1. Initial incision: The point of choice for the beginning of the incision should be based on two important aspects: the margin of the healthy bone segment and the mental foramen. The initial incision should be made in the alveolar mucosa using an electric scalpel with a microdissector on both vestibular and lingual aspects (Figure 2.G). The attached gingiva is preserved in the dentate segment that will be removed with the resection.

Step 2. Mucoperiosteal detachment: The detachment and dissection of healthy soft tissues should start from the healthy bone toward the regions affected by tumor growth (Figure 1.G). It is recommended to maintain the integrity of the periosteum as it will provide the anatomical reference for subsequent plane dissection. Special attention should be given to the points of bone fenestration that may be infiltrated by the tumor and require supraperiosteal dissection. In these cases, it is important to carefully dissect the remnants of the bone cortex that have undergone expansion and thinning due to the growth of the lesion.

Step 3. Management of the mental neurovascular bundle: If the resection involves the mental foramen, the neurovascular bundle will be severed to ensure the safety required margin. To achieve this, it would be important to perform ligation and sectioning of the inferior alveolar nerve at its distal end before it exits the mental foramen, thereby obtaining greater mobility of the flap, consequently providing broad access and visualization to the posterior region.

Step 4. Anterior osteotomy: Along the detachment, the newly formed vessels around the tumor should be cauterized or ligated with cotton thread. As dissection progresses to the posterior region, access and visualization become more restricted. An alternative to gaining mobility is performing the osteotomy at its most anterior portion. With the aid of a grasping instrument (Allis or Kocher) attached to the osteotomy site and pulling the block laterally (Figure 1.H-J).

Step 5. Coronoidectomy and Tumor segmentation: In cases where the lesion extends to the condylar process, two surgical strategies can be used to assist in tumor removal. The first is the removal of the coronoid, which provides better mouth opening and anteriorization of the ramus by posterior segment translation. The second strategy is the division of the lesion in the retromolar region for removal in two segments (Figure 2.J-K).

Step 6. Management of the inferior alveolar neurovascular bundle: During dissection of the medial aspect of the ascending ramus of the mandible, it is important to ligate and section the inferior alveolar neurovascular bundle at its proximal end at the entrance of the mandibular foramen. This maneuver can be performed with the aid of large hemostatic forceps associated with electrocautery or ligature. Another measure to prevent intraoperative bleeding is maintaining the integrity of the periosteum on the medial aspect of the ascending ramus.

Step 7. Disarticulation: For disarticulation, one should combine pulling the ramus downward with blunt dissection of periarticular structures. This dissection can be performed using digital maneuvers, gauze soaked in saline solution, or with the blunt edge of a periosteal elevator (Figure 1.I-J; Figure 2.J).

Step 8. Considerations for reconstruction: After resection with safety margins via the intraoral approach, the recipient bed is ready for primary reconstruction, either with alloplastic materials or bone grafting (Figure 2). In all cases, the recipient bed remains with facial and cervical vessels of interest for reconstruction preserved.

Step 9. Tissue synthesis: The musculature of the mouth floor and tongue should be sutured along the reconstruction plate, preferably with 3-0 polypropylene suture and horizontal mattress sutures. The more superficial plane should be closed in two layers: a deeper layer with horizontal mattress sutures and a superficial layer with a continuous suture technique (simple or blanket), both using 3-0 monofilament absorbable suture.

Discussion

Surgical resections via intraoral approach constitute an important alternative in reducing morbidity associated with the treatment of mandibular tumors requiring unilateral TMJ disarticulation. Advantages include adequate visualization of target structures, with or without minimal external incisions; reduced surgical time; reduced soft-tissue dissection; and preservation of facial and cervical vascularization.

Resections involving the TMJ through intraoral access have already been described for small lesions restricted to the mandibular condyle [⁵]. In cases of larger mandibular tumors involving the condyle, angle, and mandibular body [⁶,⁷], surgeons typically opt for transcutaneous approaches to ensure wide visualization and facilitate disarticulation. However, the tumor size does not appear to be a limitation for intraoral approaches, even in cases where the cortical bone is compromised. Complete removal of the lesion with safety margins and greater preservation of adjacent facial anatomical structures is still possible without resorting to transcutaneous approaches.

One main advantage of this technique is its ability to reduce aesthetic defects, which are inevitable with extraoral access. Wang et al. [⁷] compared the intraoral and transcervical approaches, finding that the first resulted in fewer complaints about appearance due to the absence of external scars. Additionally, Wang et al. [⁷] observed that graft vascularization was higher in patients approached via intraoral incisions, with only one patient experiencing vascular compromise compared to three patients in the extraoral incisions group. Once there is no need for cervical vessels ligature, intraoral approaches seem to succeed in preserving recipient site vascularization, which is crucial for graft survival in mandibular reconstructions.

Conclusion

Ablative surgical procedures for mandibular tumor management significantly impact patients’ quality of life. In this regard, aesthetic and functional complaints related to postoperative defects can be alleviated by the choice of surgical approach. Therefore, enhancing the resection technique with unilateral temporomandibular joint disarticulation via an intraoral approach offers benefits and, even in the presence of extensive mandibular lesions, allows preservation of recipient-site vascularization and perioral soft tissues while avoiding visible scars. Nevertheless, further clinical studies are necessary to better elucidate the safety and effectiveness of this technique before it can be recommended for routine clinical practice.

Financial Support

None.

Data Availability

The data used to support the findings of this study can be made available upon request to the corresponding author.

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Correspondence

Corresponding author: André Gustavo Góes da SilvaE-mail:[e-mail]

Academic Editor:

Alessandro Leite Cavalcanti

Conflict of Interest

The authors declare no conflicts of interest.

Publication Dates

• Publication in this collection
  31 Aug 2026
• Date of issue
  2026

History

• Received
  18 Sept 2025
• Reviewed
  15 Nov 2025
• Accepted
  05 Dec 2025