Evaluation of Functional and Esthetic Outcome of Patients After Reconstruction with Mandibular Reconstruction Plates Preceded by Resection of Benign Odontogenic Neoplasms of Mandible: A Cohort Study

Abstract

Large benign odontogenic neoplasms of mandible are not rare in developing countries such as India. Treatment of choice depends not only on extent and size of the lesion but also the socio-economic status, resources and available armamentarium. Whenever resection of segment mandible is planned for these patients, goal of the treatment should not be to restore function of the mandible alone but also to give esthetic visual appearance of the face. The present study was performed to determine postoperative functional and esthetic outcome in such patients. A total of 18 patients (20–35 years) with benign odontogenic neoplasm of mandible were enrolled for the study. After surgical intervention i.e., resection and reconstruction of mandible with mandibular reconstruction plate, all the patients were evaluated post-operatively for functional and esthetic outcome at the end of 1st and 4th week. Functional outcome were assessed based on Quality of life questionnaire and esthetic outcome based on vancouver scar assessment scale, clinical and radiological assessment. The mean scores of all the functional outcomes was improved significantly like pain, drooling of saliva, eating solid and liquid and speech except deglutition. The mean score of scar was recorded as 4.67. Occlusion was achieved in 100% and lips competency in 89% of patients. It is advised to immediately reconstruct the mandible after segmental mandibulectomy which eventually helps to improve the quality of life post-operatively of patients being treated for benign odontogenic neoplasm of mandible

Introduction

Improvements in plastic and reconstructive surgery and the increasing use of prosthetic appliances have removed the fear of disfigurement, poor phonation, and difficulty in masticating and swallowing after resection of the mandible [1]. Resection of segment mandible is generally avoided for benign conditions but it is not unusual in maxillofacial surgery. The most common benign tumors of mandible which frequently requires surgical resection of segmental mandible include ameloblastoma and keratocystic odontogenic tumor. It has been recently proposed to name these tumors “keratocystic odontogenic tumors” rather than “odontogenic keratocysts”, because the former more appropriately reflects their potential for local, destructive behavior [2]. Ameloblastoma is the most common neoplasm affecting the jaw. It is an aggressive benign tumor of epithelial origin that may arise from the enamel organ, remnants of dental lamina, the lining of an odontogenic (dentigerous) cyst, or possibly from the basal epithelial cells of the oral mucosa [3].

The common denominator of the large aggressive odontogenic tumors, apart from keratocystic odontogenic tumors, is that they give rise to buccal and lingual swelling and to a certain extent, soft tissue expansion but least soft tissue invasion. Resections, therefore, usually do not lead to major soft tissue deficits, which are often seen after resection in malignancies. Most of the odontogenic tumor predominantly affect individual at early age. Thus, when considering for resection of segment mandible immediate reconstruction should also be the focus as most of the patients are young and has a future life ahead postoperatively.

Previous researches revealed below par results in patients undergoing this type of resection without bony reconstruction affecting their social and habitual life negatively [1, 4]. An affordable and effective means of immediately reconstructing these patients would contribute considerably to their well being. Considering this background, the present study was performed on patients with benign lesions of mandible needed to undergo surgical resection followed by immediate reconstruction and thus evaluate its esthetic and functional outcome postoperatively.

Materials and Method

The study was initiated after the protocol had been approved by the Institutional Committee of Research Ethics. This was a cohort study done at the department of Oral and Maxillofacial Surgery, Dental Institute, Rajendra Institute of Medical Sciences, Ranchi from December 2017 to December 2019. A total of 18 patients were enrolled in the study and belonged to the age group of 20–35 years. All the subjects were being explained about the importance of the study and written informed consent obtained.

Patients diagnosed as benign odontogenic tumors of mandible and underwent segmental resection of mandible with immediate reconstruction with reconstruction plates were included in the study. These cases were diagnosed after complete clinical examination, radiographic and histopathological evaluation. Patients with malignant tumors of mandible, immunocompromised patients, patients undergoing resection of mandible without marginal mandibular defect, patients with skin involvement and massive disease extending beyond the boundaries of the oral cavity were excluded from the study.

All the patients were operated under general anesthesia by the maxillofacial surgeons of our department and a standard protocol for surgery was adopted. The lesion was exposed by submandibular incision and extended depending on size and location of lesion followed by resection of the segment mandible with the help of burs, chisel, mallet and Gigli saw. Reconstruction was then done with 2.5 mm titanium reconstruction plates with 10 mm screws with or without condylar head according to the need. Surgical site was closed with sutures and drain placed if required. Fig. 1 Different kinds of reconstruction plates used were angular, straight and recon plate with condylar head as shown in Fig. 2.

Fig. 1.

a Preoperative profile of the patient diagnosed with ameloblastoma of the mandible, b surgical intervention, c postoperative intubation, d postoperative radiograph

Fig. 2.

a Angular reconstruction plate (left and right), Intra-operative placement, Post-operative OPG; b straight reconstruction plate, Intra-operative placement, post-operative OPG; c reconstruction plate with condylar head (left and right), Intra-operative placement, post-operative OPG

All the 18 subjects were evaluated postoperatively for functional outcome such as pain, drooling of saliva, eating solid/liquid, tongue movement, deglutition, speech and esthetic outcomes such as apparent scar, lips competency and occlusion. Functional outcome was assessed based on Quality of life (QOL) questionnaire adapted from EORTC H&N C-30 [5]. Esthetic outcome was assessed based on vancouver scar assessment scale and clinical and radiological assessment [6]. The subjects were followed up after end of 1st week and 4th week. All the data obtained was recorded in a proforma specially designed for the study. Comparison of all the parameters in both the time intervals was performed using student t-test using SPSS version 16.01 software. Significance level was considered at 5% (p value < 0.05).

Results

Among 18 patients, 10(56%) were males and 8(44%) females with mean age of 24 y. 11(61.1%) patients were diagnosed with ameloblasoma, 6(33.3%) with keratocystic odontogenic tumor and 1(5.6%) patient with myxoma. Lesions were predominantly present on the left when compared to right side with a ratio of 5:4. 11(61.1%) patients had defect involving condyle and reconstruction plates with condylar head were placed in them. The remaining 7(38.9%) patients had angular reconstruction plates placed.

Evaluation of Pain

The mean value of pain was 2.83 after first week which gradually reduced to 1.83 at the end of fourth week which was statistically significant with t value of 4.51 and p value < 0.05.

Drooling of Saliva

The mean score was 2.05 and 1.27 at the end of first and fourth week respectively with t value of 3.95 and p value is < 0.05 which was statistically significant.

Eating Solid/Liquid

The mean score was only calculated after fourth week i.e., 2.88.

Evaluation of Tongue Movement

The mean score was 2.55 after the first and 1.61 at the end of fourth week which was statistically significant with t value of 2.21 and p value < 0 0.05.

Evaluation of Speech

The mean score of the patients decreased from 3.22 to 2.0 at the end of fourth week with t value of 5.16 and p value < 0.05.

Deglutition

The mean score was 2.44 at first week and 1.83 at the fourth week which was statistically non significant t value of 1.12 and p value is 0.13 (Tables 1, 2).

Table 1.

Mean scores of all the patients of functional evaluation after 1 week

Parameters	1	2	3	4	Mean score
Pain	0	6	9	3	2.83
Drooling of saliva	5	8	4	1	2.05
Eating solids/liquids	Nil	Nil	Nil	Nil	Nil
Tongue movements	3	3	10	2	2.55
Speech	0	3	8	7	3.22
Deglutition	5	7	4	2	2.44

Scores: 1: not at all; 2: a little bit; 3: quite a bit; 4: very much

Table 2.

Mean scores of all the patients of functional evaluation after 4th week

Parameters	1	2	3	4	Mean score
Pain	5	11	2	0	1.83
Drooling of saliva	14	3	1	0	1.27
Eating solids/liquids	2	3	8	5	2.88
Tongue movements	5	6	7	0	1.61
Speech	4	10	4	0	2.0
Deglutition	7	7	4	0	1.83

Scores: 1: not at all; 2: a little bit; 3: quite a bit; 4: very much

Esthetic Outcome

Apparent scar was recorded with the help of vancouver scar scale after 4 weeks and the mean score was 4.47. (Fig. 3) Lips competency was present in 16 patients and occlusion was observed in all the 18 patients.

Fig. 3.

Graph showing distribution of scores of esthetic outcome via Vancouver scar scale

Discussion

Life of any patient who has undergone segmental resection of mandible is never the same as before. Although benign tumors of mandible have slow rate of expansion and destruction of bone, many of the patients present with very extensive growth due to negligence and ill information, in which conservative treatment of the lesion doesn’t remain an option.

Conservative management of keratocystic odontogenic tumors has been suggested in the past, but when there is extensive involvement in the mandible or perforation to the soft tissue or in recurrent cases wide resection of segment mandible is advocated [7, 8, 9]. Similarly literature shows that some cases of ameloblastoma can be treated conservatively including marsupialization and enucleation followed by sufficient bone curettage, thus reducing the need for jaw resection with using more radical approach [10]. Management for myxomas depends upon the extension of the lesion. However, considering the non-capsulated nature of the tumor and tendency to infiltrate locally, aggressive surgical enucleation is advisable [11].

The ideal procedure following segmental mandibulectomy would be a free flap using fibula, iliac crest or scapula for rigid reconstruction [12, 13]. Free fibula flap is advantageous compared to other free flaps. The main advantage is the considerable length of available bone around 20 cm that can be obtained. It provides good result functionally and structurally in children particularly in mandibular symphysis region. In case of extensive mandibular reconstruction, two or more osteotomies are required to make desired shape and causes destruction of the centromedullary fibular pedicle. It also provides unsighty scars particularly for women in lateral part of legs. Free fibula flaps are advisable in young patients as it can be used for dental implant placement and denture rehabilitation. Reconstruction plates are advisable in patients who are medically compromised and not advisable in secondary surgical site such as ischemic disease of lower limbs and metabolic bone disorders[14].

The ultimate goal of our institution is to provide better and affordable treatment to such patients. In our study, we have included the cases which were reconstructed solely using reconstruction plates. We have seen clinically and also reviewed the literature that resection without doing any reconstruction have ill effect not only esthetically but also functionally. Simon et al. [15] reported a QOL study on a group of patients with ameloblastoma who underwent this type of resection without bony reconstruction, revealed rather poor results. Those patients had serious problems with chewing and speaking, which affected their social life negatively [15]. Kim [16] analyzed 41 cases of mandibular reconstruction and concluded as to prevent wound dehiscence and delayed exposure of the plates, particularly in reconstruction of the anterior mandible, consideration of adequate soft-tissue coverage free of tension, proper stabilization without dead space, appropriate shaping of the plate with emphasis on undercontouring or lingual placement is indicated [16].

We had prepared a questionnaire to evaluate both objective and subjective outcome with our own experience in treating the patients diagnosed with benign odontogenic tumors of mandible and treated with wide excision and segmental resection of the mandible. It was observed that a proper counseling before initiation of the treatment helped the patient to recover fast from postoperative mental, emotional and physical distress. The results of our study showed that all the functional parameters like pain, drooling of saliva, tongue movement, speech except deglutition improved significantly during the postoperative follow up of four weeks. Statistically non-significant (p value-0.13) improvement in deglutition could be correlated to the fact that these patients were routinely kept under nasogastric tube feeding initially for 7–10 days whereas some patients were under intermaxillary fixation for 2 weeks. Yet ease of deglutition remarkably improved and the patients reported positively during further follow up.

Messina [17] elucidated that the tongue, mandible, hyoid system is functionally composed by two bony components, the hyoid and the mandible and one muscle component, the tongue. They are functionally arranged as follows: from the apophysis geni superior there is the origin of the genioglossus, from the inferior the geniohyoid muscle, the first an intrinsic tongue muscle the latter that inserts distally on the hyoid bone [17]. In most of the cases during resection of the mandible segment, underlying muscles attached to it such as muscles of mastication, mylohyoid, supporting muscles of deglutition are severed from their attachment and underlying periosteum is scrapped. Genioglossus and geniohyoid is detached whenever anterior segmental mandibulotomy is done. In such cases, tongue musculature was sutured to the reconstruction plate itself to prevent tongue fallback and also to reduce need of tracheostomy [18]. It tends to restrict the tongue movement and tongue-palate contact and prevent formation of seal during deglutition and lip seal. Along with postoperative pain, oedema and above mentioned factors, it results in drooling of saliva, difficulty in chewing and dysphagia. Owing to muscle reminiscence, it tends to attach to the reconstruction plate and the functions tend to improve.

Esthetic improvement of scar was noted and was generally hidden due to submandibular approach of treatment which was given following the Langer’s skin tension line and patients were generally satisfied with the outcome. In maxillofacial surgery, occlusion is one of the most important criteria in post operative evaluation. Patients with mild occlusal discrepancy were kept in inter-maxillary fixation for a period of two weeks, which ensured that occlusion and facial symmetry in achieved. Lips competency was seen in 16 out of 18 patients (89%) giving further evidence of acceptable visual rendering of the patients.

We had also encountered some unplanned complications. One patient was kept under prolong intubation after surgery for 18 h, as anesthetist wasn’t sure whether the tongue will sustain the position or not. Two of the patients in which reconstruction plate with condylar head was used, reported with displaced condylar head during post-operative follow up and were further treated with pressure bandage application. One patient had reconstruction plate broken after 17 months of surgery and was operated again with reconstruction plate reinforced with posterior iliac crest graft [19].

Conclusion

Sometimes the treatment of choice for benign odontogenic tumors between conservative and aggressive approach becomes difficult. Large tumors alone, or with soft tissue involvement and previously failed conservative treatment cases require aggressive approach such as resection and it is also advocated to immediately reconstruct the mandible with available means and resources. Reconstruction helps to improve quality of life postoperatively of such patients.

Funding

None.

Compliance with Ethical Standards

Conflict of interest

The author’s declare that they have no conflict of interest.