*Contributed equally
Trismus is one of the common complications which occur following the extraction of mandibular impacted third molars. This generally occurs due to low-grade infection, repeated muscle stimulation, as well as other causes. This symptom is usually relieved after 1 to 2 weeks; however, it may persist for >1 month post-operatively in very rare cases. The present study reports the case of a patient with trismus at 45 days following mandibular third molar extraction. The patient received local and systemic anti-inflammatory treatment, combined with incision and drainage therapy under local anesthesia. In the present study, an analysis of the factors associated with the occurrence and development of trismus is also included, as well as appropriate management strategies in order to provide an effective treatment method for affected patients and for the prevention of trismus in the future.
The extraction of mandibular impacted third molars, a routine outpatient surgery performed by oral and maxillofacial surgeons, is associated with common complications, such as trismus, pain and infection (
A 30-year-old male patient visited the Department of Oral and Maxillofacial Surgery, the Stomatological Hospital, Southern Medical University (Guangzhou, China) for the treatment of edema and pain around the crown of the left third molar that had lasted for >6 months. Informed consent was obtained from the patient for his participation in the study and for publishing the relevant clinical data. A clinical examination revealed that tooth 38 had partly erupted and was covered by a distal gingiva flap, which was slightly red and swollen. The surface caries of tooth 38 extended to the dentin layer and were accompanied by transient sensitivity to cold stimulation. There were no abnormalities in terms of probing, percussion, mobility, or mouth opening; panoramic X-ray imaging revealed the mesioangular impaction of tooth 38 (
At 8 days post-operatively, the patient returned for a routine follow-up. A clinical examination revealed slight trismus (the distance of the incisal edges between the upper and lower incisor was approximately 28 mm). No obvious edema or pain were observed in the surgical area and normal wound healing was observed. The sutures were removed following iodophor disinfection and the wound was cleaned with normal saline. The patient was instructed to perform mouth-opening training with a hot compress and physiotherapy. Finally, the patient was provided oral hygiene education and asked to return for clinical follow-up when he experienced discomfort mainly due to slight trismus.
At 30 days post-operatively, the patient presented with trismus which had not disappeared; it had gradually worsened after self-opening training. A clinical examination revealed that the wound in the area of tooth 38 was covered with food residue; the surrounding soft tissue was red and swollen. There was no sign of pyorrhea in the area of tooth 38. The buccal mucosa was swollen and a sensation of motion was not obvious. The extent of mouth opening was approximately 2 mm (
Following 3 days of systemic anti-inflammatory treatment, there was a slight improvement in the trismus symptom of the patient; edema and pain had faded in the left submandibular region, and the extent of mouth opening was approximately 10 mm (
At 42 days post-operatively, the patient returned for follow-up and presented alleviation of trismus. The extent of mouth opening was approximately 25 mm, indicating slight trismus (
The extraction of third molars can easily lead to tissue injury, inflammation and other post-operative complications, among which trismus is one of the most common (
Early during the course of the disease, the patient of the present study exhibited mild trismus. However, this did not receive extensive monitoring as it was presumed to be related to postoperative edema and anxiety. However, when more severe trismus was observed in combination with marginal osteomyelitis, the attending physician intervened with a treatment plan for management of marginal osteomyelitis. Due to the delayed diagnosis by the attending physician, the disease treatment was delayed, which affected the patient's post-operative recovery and daily activities. Based on the intraoperative findings, the absence of the lingual bone plate in the apical region was presumed to be the main cause of marginal osteomyelitis. It was hypothesized that the following was the possible cause of trismus: An infection after tooth extraction spreads along the lingual space of the mandible. Inflammatory mediators can cause irritation associated with muscle tendon attachment to the mandibular ramus and the anterior section of the medial pterygoid muscle, thereby resulting in masticatory muscle spasms that lead to trismus.
For the patient in the present study, at 33 days post-operatively, the surgeon performed incision and drainage in the area of tooth 38 to eliminate a large amount of bloody exudate. The progressive trismus was presumed to result from long-term contact between low-toxicity inflammatory exudate and the muscle tendon. Tight suturing had been performed at the end of surgery. Notably, the inflammatory exudate could not drain with sufficient speed; thus, it spread along the lingual space of the mandible and interacted with the medial pterygoid muscle, which caused fascial space infection associated with marginal mandibular osteomyelitis. Treatment of chronic osteomyelitis has been a major focus in the field of maxillofacial surgery; the main sources of chronic osteomyelitis include odontogenic infection and tooth extraction-related infection (
Tolstunov
In conclusion, the extraction of an impacted mandibular third molar is a very common oral surgery procedure. During the surgery, the surgical area should be protected, and careful assessment is necessary regarding fracture or loss of the lingual bone plate. Effective drainage of inflammatory exudates should be performed to prevent muscle spasms and trismus caused by chronic contact with low-toxicity inflammatory exudates.
Not applicable.
The present study was supported by the Sun Yat-Sen Scientific Research Launch Project (grant no. YXQH201901), the Natural Science Foundation of Guangdong Province, China (grant no. 2018A0303130106 and 2018A030313759).
The data used during the present study are available from the corresponding author on reasonable request.
YZ, PZ, BJ, ZW and ZZ conceived the case report, wrote the initial manuscript and reviewed the final manuscript. JX, QC, LN, ZW and ZZ interpreted and created the clinical and radiographic images, and reviewed the final manuscript. All authors read and approved the final manuscript.
The patient provided informed consent for his involvement in the present study.
The patient provided informed consent for the publishing of the relevant clinical data.
The authors declare that they have no competing interests.
Panoramic X-ray imaging showing mesioangular impaction of tooth 38 (white rectangular region) and distocervical low density in the area of tooth 37 (red arrow).
(A) The extent of mouth opening was approximately 2 mm at 30 days postoperatively. (B) Panoramic X-ray imaging demonstrating reduced bone density in the left mandible (white rectangular region) and tight occlusion of anterior teeth without a gap. (C-E) Cone beam computed tomography could not clearly discern the repair to bone in the alveolar fossa of tooth 38. The lingual bone plate in the root tip area was missing (C and D, white arrows) and 3-dimensional reconstruction of CBCT images also revealed the absence of the lingual bone plate (F and G, white rectangular region); moreover, obvious lamellar periosteal hyperplasia was present in the corresponding area (D and E, red arrows). Some areas of the lingual bone plate were slightly rough (E, white rectangular region), and the soft tissue gap was difficult to discern in the bottom of the left side of the mouth. These radiologic features indicated marginal osteomyelitis of the left mandible.
The extent of mouth opening was approximately 10 mm after 3 days of systemic anti-inflammatory treatment (33 days post-operatively).
(A) The extent of mouth opening was approximately 25 mm, indicating slight limited mouth opening. (B) An occlusal pad was placed to achieve compulsory mouth opening and the extent of passive mouth opening was approximately 38 mm.
(A) Panoramic X-ray imaging (white rectangular region) and (B-D) cone beam computed tomography (white rectangular region) revealed new bone formation in the alveolar fossa within the area of tooth 38 at 1 year post-operatively.
Routine blood examination results.
Parameter | Value | Reference range | Unit |
---|---|---|---|
White blood cell count | 7.6 | 3.5-9.5 | 109/l |
Lymphocyte count | 2.4 | 0.8-4.0 | 109/l |
Neutrophil count | 0.3 | 0.1-1.5 | 109/l |
Neutrophilic granulocyte count | 4.9 | 2.0-7.0 | 109/l |
Percentage of lymphocytes | 32.2 | 20.0-40.0 | % |
Percentage of neutrophils | 3.8 | 3.0-15.0 | % |
Percentage of neutrophilic granulocytes | 64.0 | 50.0-70.0 | % |
Red blood cell count | 5.04 | 4.30-5.80 | 1012/l |
Hemoglobin level | 159 | 130-175 | g/l |
Hematocrit level | 45.6 | 40.0-54.0 | % |
Mean corpuscular volume | 90.5 | 80.0-100.0 | fl |
Mean corpuscular hemoglobin | 31.5 | 27.0-34.0 | pg |
Concentration of mean corpuscular hemoglobin | 348 | 320-360 | g/l |
Red blood cell distribution width, coefficient of variation | 12.9 | 11.0-16.0 | % |
Red blood cell distribution width, standard deviation | 42.5 | 35.0-56.0 | % |
Platelet count | 174 | 125-350 | 109/l |
Mean platelet volume | 8.2 | 6.5-12.0 | fl |
Platelet distribution width | 15.7 | 9.0-17.0 | fl |
Plateletcrit level | 0.142 | 0.108-0.282 | fl |
Details of systemic anti-inflammatory treatment administered intravenously for 3 days.
Treatment | Dose | Frequency | Days |
---|---|---|---|
0.9% sodium chloride injection | 100 ml | Twice daily | 3 |
Clindamycin phosphate for injection | 0.6 g | Twice daily | 3 |
5% glucose and sodium chloride injection | 250 ml | Once daily | 3 |
Vitamin C injection | 2 g | Once daily | 3 |
Dexamethasone phosphate sodium injection | 5 mg | Once daily | 3 |
Ornidazole and sodium chloride injection | 0.5 g | Once daily | 3 |