Surgical corrections for the success of
Fixed partial dentur
Tooth loss is one of the ageing processes. There are many causes of tooth loss including caries, periodontitis, trauma, and extraction with surgical excision of tumours. Loss of tooth can develop many problems like drifting of adjacent teeth towards the space created by lost tooth that can lead to malalignment of teeth, exposure of roots, caries and sensitivity. It can also cause loss of adjacent alveolar process and the soft tissues around it. The amount of supportive tissue loss depends on the severity of the cause. Ridge defects can also develop due to trauma, difficult extraction and different pathologies. These defects are common and contribute to esthetic problems when they occur anterior to the first premolar. Although esthetics is not a primary consideration in the posterior regions, restoring these defects with augmenting the ridge helps in plaque control. So replacement of the lost teeth and the deficient supporting tissues should be restored for an esthetic outcome and plaque control. These defect of hard and soft tissues can be restored by surgical intervention.
After the loss of a natural tooth, the bone gets resorbing. The resorption is more in the mandible than the maxilla.
Pattern of Resorption
The pattern of bone loss differs in maxilla from mandible. In the maxilla, usually, resorption is on the buccal and inferior portion of the alveolar ridge. The mandible resorbs downward and outward, causing rapid flattening of the ridge with the greatest loss occurring within 12-18 months after extraction.
In order to provide a simplified method for categorizing the residual ridge, J. L Cawood and R. A. Howell." develop a following classification. This self-descriptive system is useful clinically as well as for research purposes. 
Class I - dentate.
Class II - immediately post extraction.
Class III - well-rounded ridge form
Class IV - knife-edge ridge
Class V - flat ridge form
Class VI - depressed ridge form.
The proper selection of the case, careful diagnosis, preparation and construction of prosthesis are mandatory for the success and longevity of restoration and maintenance of health of tissues. Both general factors and systemic bone disease such as osteoporosis, endocrine dysfunction may affect bone metabolism. Surgical treatment must begin with a thorough history and physical examination of the patient. There are certain contraindications to surgery when the patient suffers from serious general disease. An extremely important part of the history taking is to know the patient’s chief complaint and expectations from surgical and prosthetic treatment. Esthetic and functional needs are very important for the patients. Examination includes inspection, palpation and specific radiographic investigations.
An extraoral and intraoral examination should include:
· Assessment of tooth relationships",
· The amount and contour of the remaining bone",
· Soft tissue overlying the concerned area",
· Depth of the vestibular",
· Muscle attachments",
· Relationships of jaws.
A defective ridge may be one of the causes of failure of FPD. It leads to problem related to both esthetic and function. Preprosthetic surgery is a part of dentistry that has a close connection to prosthodontics and oral and maxillofacial surgery. It includes surgical procedures required to be done so that the subsequent placement of the prosthesis is successful. The main function of preprosthetic surgery is to improve the defective ridge.
Good shell had recommended the following criteria for a healthy ridge:
1. The bony ridge should have sufficient width and height.
2. The oral mucosa should have an adequate and uniform thickness.
3. The ridge should not have any undercut or sharp ridge.
4. No bony /soft tissue protuberance should be present.
5. It should have adequate buccal and lingual sulci depth.
Some patients require minor oral surgical procedures before receiving a partial denture, in order to ensure the maximum level of comfort. A denture needs proper setting on the bone ridge and associated soft tissues, so it is very important that the bone is of the proper shape and size. Every effort should be made to ensure that both the hard and soft tissues are developed in a form that causes treatment success It is the responsibility of the practitioner to carefully evaluate and identify the need for any alteration and to educate the patient as to the importance of accomplishing this vital procedure.
Willard (1853) was the first American dentist to do the reduction of interdental gingival papillae and alveolar margins after dental extractions. In 1876, Beers described the cutting of the bone if the alveolar process is sharp and prominent. Molt, in 1923, performed alveoloplasty retaining the interdental septum. Dean, in 1936, performed alveoloplasty by removing interseptal bone and collapsing buccal cortical plate. Preprosthetic surgery emerged from a ridge trimming to a reconstructive surgery when Kazanjian reported labiobuccal vestibuloplasty procedures to provide an additional denture-bearing surface for increased denture stability. His technique was modified by Godwin (1947), Clark (1953), and Obwegeser(1963).
Pre-prosthetic surgery has an important role of oral and maxillofacial surgery and prosthodontics. It includes both basic procedures and sophisticated techniques of reconstructions and rehabilitation of oral and maxillofacial region. Therefore treatment planning should involve coordination between the prosthodontist and oral maxillofacial surgeon.
Objectives of Pre-prosthodontic Procedure:
Correcting conditions that prevent optimal prosthetic function
1. Hyperplastic replacement of resorbed ridges
2. Unfavourably located frenular attachments
3. Bony prominences undercut
Enlargement of denture bearing areas
2. Ridge augmentation
Types of Pre-Prosthetic Surgery
The process of shaping of alveolar process is alveoloplasty which is indicated after almost every tooth extraction, whether it is single or multiple. In this process, labiobuccal alveolar bone along with some interdental and interradicular bone is removed. Alveoloplasty which is carried out at the time of extraction of teeth is known as primary alveoloplasty.
When surgery is planned on the alveolar ridge, the incision should be made on the crest of the ridge, releasing incision can also be made on the labial side to provide a broad base to the flap. Bone contouring is done with the help of bone files, rongeurs, or burs. Pressure on the mental nerve will cause pain. Spicules and the knife-edged ridge must be reduced to avoid constant irritation of soft tissue being pinched between the denture and the bone.
An uneven alveolar ridge will result in an improper fit and unesthetic appearance. Sore spots can also develop due to uneven pressure from the prosthesis. Ragged bone is the result of tooth removal, which can leave uneven bone around the extraction site.
Removing Excess Bone
Even the small bony growth can create many problems and need to be removed. It can affect the prosthesis fit as well as esthetics. Exostosis is the abnormal bony growth in relation to the edge of the ridge. Exostosis is more common in the mandible than the maxilla.
Superior border augmentation
Davis described it in the year 1970. This procedure is done when mental foramen is located in the superior border. In this surgery, an autogenous bone graft is used. The rib graft is fixed to the upper border of the mandible. Fixation is done by transosseous wiring or circumferential wiring.
1. Donor site morbidity
2. Second surgical site
3. Withdraw denture for a period of 6-8 months till the surgical wound heals.
Inferior border augmentation - Visor osteotomy
In 1986 Sanders and Cox described this technique for reconstruction of a resected mandible. This procedure can prevent and manage fractures of an atrophic mandible.
Visor osteotomy was described by Harle to overcome the resorption of free onlay bone graft. This technique is followed where the muscle insertion to the mandible and nutrient supply is maintained. In this procedure, mandible is divided buccolingually by a vertical osteotomy from the external oblique ridge of one side of the mandible to the other side. The osteotomized lingual segment is pushed superiorly and fixed with the buccal segment using stainless steel wire in the lower border of the lingual segment.
Excess Gum Tissue removal
Excess or irregular soft tissue can result in an ill-fitting and unesthetic denture. Abnormal loose soft tissue can be excised under local anaesthesia and generally, it heals without any complications.
Vestibuloplasty is done to build an insufficient alveolar ridge. It is a surgical procedure in which oral vestibule is deepened by changing the soft tissue attachments. Vestibuloplasty can be done either on the labial or on the lingual side.e:g Kazanjian′s technique
In pre-prosthetic surgery, recovery depends on the type and extent of your procedure. Pain and swelling are common findings after most surgical treatments. Medicines like analgesics, anti-inflammatories, and antibiotics will prevent from developing any infection and also minimizes discomfort and promotes healing.
For several days soft food is advised and then gradually expanding the diet as healing progresses. Spices and foods with small pieces, like popcorn, nuts, and seeds should be avoided as it can irritate the surgical site.
Risks and Potential Complications
There are many surgical complications that can lead to fixed partial denture (FPD) failure.
· Excessive bleeding
· Bone necrosis
· Unwanted tissue growth
· Bone reabsorption
· Allergic reaction
· Rejection of a bone graft
· Nerve damage
The Benefits of Pre-Prosthetic Surgery
· It provides better stability and retention.
· It also facilitates measures to take oral hygiene and hence decreases the risk of disease and halitosis.
· It allows systemic wellness.
· Pre-prosthetic surgery enhances facial appearance.
Pre-prosthetic surgery is a part of oral and maxillofacial surgery which help to restores function and facial form. Surgical modification of the alveolar process and its surrounding structures is done for the fabrication of a prosthesis with proper-fitting, comfort, function and esthetics.
. J. L Cawood and R. A. Howell." A classification of the edentulous jaws. Int. J. Oral Maxillofac. Surg. 1988; 17:232-236
. Harrison A. Temporary lining materials. A review of their uses. Br Dent J. 1981;151:419–22.