Topic: Clinical case report

References Conclusions

Introduction

Posterior alveolar ridge augmentation:

An onlay technique using autogenesis intra oral

mandibular tori (benign bone exostosis)

*D.McAnerney, OMFS registrar1, M. El-Belihy, OMFS DCT1,

R.Cousley, Orthodontic Consultant1, M.Turner, OMFS Consultant1, K. Malik, Restorative Consultant1 1Peterborough and Stamford NHS Foundation Trust. UK

1. Mischkowski RA, Selbach I, Neugebauer J, Koebke J, Zoller JE. Lateral femoral cutaneous nerve and iliac crest bone grafts–anatomical and clinical considerations. Int

J Oral Maxillofac Surg. 2006; 35:366–372.

2. A Joshi & G C Kostakis An investigation of post-operative morbidity following iliac crest graft harvesting Br Dent J. 2004 Feb 14;196(3):167 – 171

(http://www.nature.com/bdj/journal/v196/n3/full/4810945a.html )

3. Jun JH, Peacock Z, Pogrel MA: Alveolar ridge augmentation using lingual tori. (J Oral Maxillofac Surg. 2010 Nov;68(11):2906-8)

4. Ganz SD: Mandibular tori as a source for onlay bone graft augmentation: A surgical procedure. Pract Periodontics Aesthet Dent 9:973, 1997

5. Proussaefs P: Clinical and histologic evaluation of the use of mandibular tori as donor site for mandibular block autografts: Report of three cases. Int J Periodontics

Restorative Dent 26:43, 2006

6. Drew H, Zweig B: Use of a buccal exostosis autograft for alveolar ridge augmentation: An aid to implant placement. J N J Dent Assoc 78:40, 2007

7. Neiva RF, Neiva GF, Wang HL: Utilization of mandibular tori for alveolar ridge augmentation and maxillary sinus lifting: A case report. Quintessence Int 37:131, 2006

8. Barker D, Walls AW, Meechan JG: Ridge augmentation using mandibular tori. Br Dent J 190:474, 2001

9. Misch C M: Comparison of Intraoral Donor Sites for Onlay Grafting Prior to Implant Placement. (Int J Oral Maxillofac Implants 1997;12:767–776)

10. Sethi A, Kaus T: Ridge augmentation using mandibular block bone grafts: preliminary results of an ongoing prospective study (Int J Oral Maxillofac Implants. 2001 May-

Jun;16(3):378-88.) http://www.ncbi.nlm.nih.gov/pubmed/11432657

11. Simunković SK, Bozić M, Prevalence of torus palatinus and torus mandibularis in the Split-Dalmatian County, Croatia.( Coll Antropol. 2011 Sep;35(3):637-41.)

http://www.ncbi.nlm.nih.gov/pubmed/220535357

12. Jainkittivong A, Apinhasmit W, Prevalence and clinical characteristics of oral tori in 1,520 Chulalongkorn University Dental School patients. (Surg Radiol Anat. 2007

Mar;29(2):125-31) http://www.ncbi.nlm.nih.gov/pubmed/17340055

13. Kolas S, Halperin V et al : The occurrence of torus palatinus and torus mandibularis in 2,478 dental patients Volume 6, Issue 9, September 1953, Pages 1134–1141

(http://www.sciencedirect.com/science/article/pii/0030422053902254 )

With natural atrophy of the alveolar ridge at sites of missing teeth, bone

augmentation can be required prior to dental implant placement. The use of iliac

crest, mandibular ramus and chin as donor sites are well documented in the

literature 1, 2 but are not without potential morbidities associated with the donor site

Previous cases have been reported where mandibular tori have been successfully

harvested and used for specific alveolar augmentation and sinus lifting

procedures.3,4,5,6,7,8 This case presents the use of mandibular tori (benign bone

exostosis) as an onlay autograft for localised alveolar ridge augmentation in the

posterior maxilla and mandible prior to the placement of dental endosseous

implant fixtures.

Introduction

When considering implant rehabilitation for missing teeth bone volume needs to be considered

for placement. With natural atrophy of the alveolar ridge at sites of missing teeth, bone

augmentation is required prior to implant fixture placement. The use of iliac crest, mandibular

ramus and chin as donor sites are well documented in the literature but are not without

morbidity. This case report describes the use of mandibular tori (benign bone exostosis) used

as an onlay autograft for localised alveolar ridge augmentation in the posterior maxilla and

mandible.

Case report

A 39 year old male presented with hypodontia, mandibular tori and an atrophic region in the

maxillary and mandibluar premolar region apical to the retained deciduous teeth. The

multidisciplinary team consisting of Orthodontics, Restorative Dentist (RD) and Oral and

Maxillofacial surgeons (OMFS) carried out full management.

Orthodontic treatment was carried out over a period of 12 months to align the arches and

optimise the space in the recipient sites. OMFS provided a single procedure of bilateral

mandibular tori harvesting, fixation of the onlay graft with titanium screws and placement of a

particulate graft Bio Oss® along with autogenous bone scrapings prior to the placement of a

resorbable non cross-linked membrane Bio Gide®. A 2 stage implant placement of 4 fixtures

was placed 6 months after the augmentation procedure and after a further 3 months the screw

retained restorative construct was placed.

Discussion

Although extra oral sites can be used they produce a second donor site which can give rise to

distant complications. Common intra-oral sites include the maxillary tuberosity mandibular

symphysis, and ascending ramus of the mandible. With such sites the success rate of intraoral

endosseous implant placement into autogenous bone grafted from intra-oral donor sites has

been shown to be up to 98.3%. With the occurrence of mandibular tori reported between 6-

32% this case shows that the mandibular tori could also be a viable source for autogenous

bone in alveolar bone augmentation for suitable cases.

Although extra oral sites can be used they produce a second donor site which can

give rise to complications. Common intra-oral sites include the maxillary

tuberosity mandibular symphysis, and ascending ramus of the mandible which

have been shown to have low associated morbidity9.

From the literature success of intraoral endosseous implant placement into

autogenous bone grafted from intra-oral donor sites has been shown to be up to

98.3%10. With the occurrence of mandibular tori reported between 6-32%11, 12, 13.

This case has shown that they are a viable source for autogenous bone in

alveolar bone augmentation for appropriate cases.

Abstract Results

Prior to surgery figure 1b shows the prominent mandibular tori. The patient was

seen for follow up appointments as per departmental protocol post operative

recovery where it was noted that healing was uneventful. The immediate plain film

OPG lower occlusal view shows where the tori have been removed and then

screwed into the final desired position (Figure 2a and b)

The 6 month plain film OPG shows the

implant fixtures placed in the lower right

first and second premolar region and the

upper left canine and second premolar

region (Figure 3)

Figure 4a and 4b show the restorative prosthesis in situ with the contacts against

the opposing arch marked on the restorations. The mandibular arch view shows

where the tori were removed 9 months previously. Figure 5 shows the final

restoration in place and the patient smiling.

Fig 6. 60mm Petri dish with 3 of each surface sample

Method

A 39 year old male presenting with hypodontia, mandibular tori and an atrophic

region in the maxilla and mandible in the premolar region apical to the retained

deciduous teeth was seen on a multidisciplinary team consisting of Orthodontics,

Restorative Dentistry (RD) and Oral and Maxillofacial Surgery (OMFS) who carried

out full management of the patient.

Orthodontics was carried out for initial alignment of the arches and optimisation of

the recipient sites over a period of 12 months (Figure 1a and 1b)

The OMFS and RD team worked jointly in the harvesting and placement of onlay

bone graft. After raising a mandibular mucopesoteal flap the lingual tori were

harvested using a fine osteotome and a mallet. The area was then smoothed using

the Safescraper®. The right mandibular and left maxillary defects were exposed.

Shaping and fixation of the autogenous onlay bone graft using 1.2mm titanium

screws was carried out in these two regions. Autogenous bone chips that had been

obtained with the Safescraper® were mixed with a particulate xenograft (BioOss®)

and this was placed on top and around the autogenous block graft prior to the

placement of a resorbable non cross-linked membrane (BioGide®).

Following surgery the retained deciduous teeth were extracted as atraumatically as

possible 3 months after the augmentation date. 6 months after the augmentation

date a mucoperostial flap was raised in the right mandibular and left maxillary

defects and the bone assessed. The 1.2mm titanium screws were removed and 4

endosseous ASTRA® dental implant fixtures were placed in the lower right

premolar region and the upper left canine and second premolar region by the RD

team. The flap was replaced and the fixtures buried under the mucosa for 3

months. Following the period of healing the fixtures were exposed with a minimal

incision and healing abutments placed prior to the restoration with screw retained

fixed construct

Fig 4a. Upper arch with screw retained restorations in place

Fig 1a. post orthodontic alignment of upper arch Fig 1b. post orthodontic alignment of the lower arch

with the prominent bilateral mandibular tori present

Fig 2b. The postoperative lower occlusal view shows the removal of

the mandibular tori (benign bone exostosis)

Figure 3: Immediate post surgical OPG and with the 4 Astra® dental implants in situ

Figure 5: Patients smiling with immediate view final implant supported restorations in place

Presented at the 4th Joint Meeting of the; European Calcified Tissue Society &

International Bone & Mineral Society

25-28 April 2015, Rotterdam

Fig 2a. postoperative OPG shows the screws fixing the autogenous lingual tori blocks in place

Fig 4b. Lower arch with implant supported screw retained

restorations in place. The removal of the tori can be noted.