Overview

Torus palatinus (TP) and torus mandibularis (TM) are the 2 most common intraoral osseous outgrowths.³ Tori may be considered as specific exostosis, formed by a highly dense and strictly limited amount of bone marrow, covered with a thin mucosa, easy to flap and poorly vascularised.² The aetiology is unknown in most cases. Tori are usually benign and don't need to be treated until they cause problems while eating, speaking, or wearing dentures; in these situations, surgery is the best course of action.

Keywords

Palatal torus, tori, surgical technique, exostoses

Introduction

Torus palatinus (TP), also known as maxillary exostosis, commonly localised in the region of the hard palate as excessive bone tissue formed slowly, is characterised by a highly dense and strictly limited group of bone marrow, covered by a thin mucosa, with little vascularisation⁴ The tori (meaning “to stand out” or “lump” in Latin) are exostoses that are formed by a dense cortical and limited amount of bone marrow.¹

These tumours elevate the midline of the palate on the cruciform suture, which connects the maxillary and palatal bones. The first report of exostotic changes of the hard palate was written by Fox in 1814. Although this anatomical variation had been described earlier under various names, the term Torus palatinus was determined by Kupffer and Bessel-Hagen in 1879.⁹ Palatal tori are characterised by slow growth, and the torus can reach a large size that requires surgical removal, for example, when representing an obstacle to prosthetic treatment.⁸

Location

The most typical site for palatal exostoses is the tuberosity area, which is located on the palatal aspect of the maxilla. Precisely located along the median palatine suture, involving both the processus palatini and the os palatinum.⁸

Prevalence

In the vast majority of cases, TP occurs more frequently than TM. Studies have indicated that TP is more common in females than in males.

Causes

The specific reason is unknown; however, it is thought to be a combination of hereditary and environmental variables, particularly those associated with occlusal stress. It has been suggested that the bony outgrowth represents a reaction to increased or abnormal occlusal stress on the teeth in the involved areas.³ 

Recent research by Eggen et al. reviewed the function of nutrition in the aetiology of tori and proposed that eating saltwater fish in Norway may provide higher levels of vitamin D and polyunsaturated fatty acids, which are involved in bone growth and raise the risk of tori.¹⁰

Types

Haugen and Eggen et al classified based on their size as:

• Small – less than 2mm
• Medium - ­­2-4mm
• Large – more than 4mm

Classification by Reichart et al:

• Grade 1 – small up to 3mm
• Grade 2 - moderate up to 6mm
• Grade 3 – above 6mm

Classification based on their shape:

• Flat tori are often symmetrical on both sides of the mouth, with a big base and a smooth, slightly convex surface
• Spindle tori appear as a maxillary midline ridge
• Lobular tori that emerge from the single base as lobulated masses
• Nodular tori, which appear as many protuberances with separate bases

Signs and symptoms

• Generally asymptomatic
• Phonatory disturbances
• Ulceration of the mucosa
• Prosthetic instability

Intraoral findings

• Solid lesion on the hard palate
• The mucosa shows ulceration in the centre of the lesion

Histopathology

Consists of solid bone with marrow gaps and a slightly spongy texture.

Indications for removal

• A huge torus that fills the palatal vault
• An extension of the torus past the area of the posterior dam
• Presence of deep bony undercuts
• Interference with speech or deglutition
• Psychological considerations
• Limitations of masticatory mechanics
• Ulcer of a traumatic origin
• Prosthetic instability and treatment

How do you diagnose a tori?

Radiodense pictures can be seen in X-rays. Therefore, in contrast to clinical diagnosis, it is not useful.

For correct clinical diagnosis, it is important to remember that torus palatinus is always symmetrical and located in the middle of the hard palate. Asymmetrical formations must be differentially diagnosed from other benign or malignant lesions.⁸

Surgical complications

• Nasal cavity perforation
• Damage to the palatine nerve resulting in secondary anaesthesia
• Bone necrosis as a result of inadequate cooling during surgical drilling 
• Palatine bone fracture
• Palatine mucosal dilatation
• Haemorrhage from a segment of the palatine arteries
• Suture opening
• Edema
• Infection
• Poor scaring

Treatment

The primary goal of surgical technique is to improve the standard of prosthetic rehabilitation and restore the orofacial region's physiological functioning without any obvious side effects or recurring difficulties.

TP removal can greatly enhance the quality of life for many patients, particularly those who have maxillary prostheses, and is a reasonably easy surgery for dental professionals with surgical training. To enhance surgical planning, new auxiliary technologies like 3D scan printing might be taken into consideration.

The surgical method was based on the initial osteotomy utilising piezoelectric devices and ample irrigation with 0.9% saline solution. For the removal of the TP, the nasopalatine nerve must be anesthetized at its exit through the anterior palatine foramen, and the anterior palatine nerves must be anesthetized through the posterior palatine foramen. In addition, the anaesthesia will be delivered via perilesional infusion to aid the separation of palatine fibromucosa.¹

Moreover, it has been demonstrated that general anesthesia might be indicated in cases of the presence of a very posterior localization and a large palatal torus.⁷

Depending on the position and shape of the palatal torus, four major types of incisions can be made.⁶

• Simple linear incision
• Y incision
• Double Y incision
• Double curvilinear incision

The most popular kind of incision is the double-Y incision since it protects the nasopalatine and anterior palatine units. For the edentulous patient, a full-thickness incision is performed along the alveolar ridge, from the right tuberosity to the left tuberosity. In dentulous patients, the incision can be made by incising through the gingival sulci and extending anteriorly from each side until it joins at the midline.

The method consists of two major phases: mucosal and bone. A full-thickness mucoperiosteal palatal flap is then reflected anteroposteriorly. If necessary, this can extend to the hard palate's posterior margin.

The flap is gently lifted around the torus, taking care not to perforate the mucosa. In addition, care is taken to preserve the greater palatine neurovascular bundle. Once the palatal flap is elevated, retraction sutures may be used to reflect the flap posteriorly and provide access for instrumentation. Reflecting a full thickness palatal flap provides greater access for palatal torus removal and protects the palatal mucosa from iatrogenic trauma.⁵

The conventional technique uses a chisel and hammers that involve the risk of traumatic injuries, hence, excision can be done using bony burs.

Castro Reino et al. advocated the use of a high speed turbine cooled with normal saline solution, given that they consider the use of a chisel and hammer involving a greater risk of iatrogenic injury, and also to avoid the bumping the patient with the chisel; however, we must take into account the risk that this may cause emphysema.¹

The surgical technique was based on the sectioning of the torus in smaller fractions in case of a large tori.

The surgical technique itself was based on the initial osteotomy using piezoelectric instruments and abundant irrigation with 0.9% saline solution; this is complemented manually with osteotomy and ostectomy with chisel and hammer. Bone remodeling is carried out immediately with gubia forceps and burs placed in a high speed hand-piece in order to provide irregular areas with a uniform aspect.

Finally, the excess covering mucosa is removed (approximately 2 cm), and primary closure of the surgical bed is performed with simple sutures. In case of a nodular tori, Periotome is used for the detachment until the nodule is exposed. In cases of pedunculate base, the palatine torus can be easily removed with a hand osteotome or by chisel.⁹

Before closing the mucosal tissue, it is crucial to make sure the mucous membrane has properly acclimated to the new palatal environment. If it hasn't formed or wasn't sufficient during the first incisions made during the treatment, a mucosal resection must be performed.

In cases of partial or complete tooth loss, a preoperatively prepared resin palatal plate or a removable prosthesis can be placed at the end of the procedure to provide local compression; this would prevent postoperative haemorrhaging, protect the mucosal wound, and decrease postoperative sensitivities.⁸

Other techniques include peeling of or smoothing of tori using Er: YAG laser.

The Er: YAG laser can be used to surgically cure bony protuberances from the cortical plate (torus palatinus, torus mandibularis) quickly and safely without endangering the surrounding tissues. This treatment uses remodelling the surface via bone-burr plus air-water spray.

The Er: YAG laser also remodels the surface through what is known as explosive vaporisation of the target tissue. Each shot (pulse) removes a little bit of bone, and the repetition rate, as well as the pulse duration, spot size, diameter, and fluence, all contribute to laser remodelling efficiency.

The energy applied to the target tissue decreases with increasing spot size; fluence is measured in Joules per centimetre square.² Er: YAG laser uses a Sapphire tip with smooth linear movement.

Advantages over conventional techniques include an excellent clinical healing process achieved with this wavelength, which may be connected to the biostimulation of the irradiated tissues, the decrease in target tissue heating, the decontaminated wound, and the lack of smear layer formation that could interfere with the healing process.

One drawback compared to the traditional method is that the floor of the mouth needs to be shielded from laser risks. The process takes a long time. There may be issues while peeling the surface since it may become uneven, and this has to do with the shots overlapping.

Er: YAG laser is not well absorbed by haemoglobin, hence the operating field is bleeding while being cleaned with an air-water spray combination: Therefore, a powerful aspiration is asked for.²

Post-operative care

Antibiotics, Anti-inflammatory and analgesic therapy are indicated, and the suture should be removed after 15 days if there are no signs of inflammation. A follow-up is done after 6 months of surgery to check for any signs of recurrence.

Conclusion

Palatal tori can only be managed surgically when necessary, to restore the physiology of the orofacial functions and/or enable prosthetic rehabilitation without causing any negative consequences. Positive clinical outcomes have been observed when TP lesions are removed using laser surgery and reduced in bulk. It is necessary to make a differential diagnosis between primary and secondary malignant tumours.