VO VAN NHAN DENTAL IMPLANT PLACEMENT ON ALVEOLAR BONE GRAFTED PATIENTS AFTER CLEFT LIP AND PALATE RESCONTRUCTIVE SURGERY Specialty: Odonto - Stomatology Code: 62.72.06.01 PH.D THESIS SUM
Trang 1VO VAN NHAN
DENTAL IMPLANT PLACEMENT ON ALVEOLAR BONE GRAFTED PATIENTS AFTER CLEFT LIP AND PALATE RESCONTRUCTIVE SURGERY
Specialty: Odonto - Stomatology
Code: 62.72.06.01
PH.D THESIS SUMMARY
Hanoi - 2014
Trang 2PHARMACEUTICAL SCIENCES
Full name of scientific instructors:
1 Assoc.Prof Ph.D Le Van Son
2 Ph.D TaAnh Tuan
Judge 1:Assoc.Prof Ph.D Trinh DinhHai
Judge 2: Ph.D Le Hung
Judge 3: Prof Ph.D Le GiaVinh
The thesis will be defended before the Thesis Assessment Council at Institute level
At , date month year
Be able to search the thesis at:
1 National library
2 108 Institute of Clinical Medical & Pharmaceutical Sciences Library
Trang 3I RATIONALE OF THE SUBJECT
Cleft lip and palate (CLP) is the most frequently reportedcongenital birth defect in the cranio-maxilo-facial field.According to WHO, the overall incidence of cleft lip and palate isreported around 1/500 live births [138] This incidence is differentdepending on regions and races:it’s low in the black and high inJapanese, Chinese and Indian-American In Vietnam, thisincidence is about 1/709 to 1/1000 [2], [7]
Around the world, some clinicians successfully appliedimplant treatment for cleft lip and palate patients like Verdi(1991) [139], Kearns (1997) [68],… In Vietnam, the research oncleft lip and palate patients mainly assess epidemiology and cleftlip - palate closing technique [1], [3], [4], [5], [7], a few studieswere takenabout alveolar bone graft such as study of NguyenManh Ha (2009) [6], or implant placement in normal patientswithout defects of Ta Anh Tuan (2007) [8] Thus, the implantplacement on the grafted bone and implant prosthetic on CLPpatient is the problem that has not been studied comprehensively
in Vietnam Meanwhile, the demand for treatment is huge sincemost CLP patients have not had bone grafts and dentalrestorations as of yet
With the desire to implement the implant technique for CLPpatients in Vietnam and perform a systematic scientific research,
we conducted the thesis " Dental implant placement on alveolar bone grafted patients after cleft lip and palate reconstructive surgery"
II RESEARCH OBJECTIVES
1 Evaluate jaw bone condition after alveolar cleft bone graft
Trang 42 Evaluate the success of implant treatment.
IV THESIS STRUCTURE
The thesis consists of 121 pages, not including appendices andreferences The contents of the thesis are: Introduction (2 pages),Literature review (31 pages), Research subjects and method (29pages), Research results (20 pages), Discussion (36 pages),Conclusion (2 pages), Recommendations (1 page) The thesis has
23 tables, 4 diagrams, 12 charts, 69 pictures, 144 references (9Vietnamese, English 135)
Chapter 1: LITERATURE REVIEW
1.1 CLEFT LIP AND PALATE
Cleft lip and palate are birth defects causing deficiency anddeformities of the nose, lips, palate that affects the formation ofunerupted tooth, teeth eruption, malocclusion, mastication,distortion of the mesial floor and inferior floor of the facial,pronunciation, the aesthetic and psychological diseases [94], [65].Therefore, those who suffer from this malformation always feelinferior andcan feel distance from community
The treatment of CLP defects is a long process from the childstill in the womb to anadult with the cooperation of many expertsand various techniques including psychological counselling,primary lip and palate repair surgery, alveolar cleft bone graftsurgery, orthodontic treatment, dental restorations, [101], [106]
Trang 51.2 ALVEOLAR CLEFT BONE GRAFT
1.2.1 The necessity of alveolar cleft bone graft
Alveolar cleft bone graftingprovides room for orthodonticmovement of the teeth in the position of #3 and #2 (canine andlateral incisor) to erupt into the cleft or for dental prosthesis,maintain bony support of teeth adjacent to the cleft, preserve thehealth of the arch and facilitates closing of the fistula in thesecondary bone grafting [138]
1.2.2 Flap preparation forgrafted recipient
Flap designs in alveolar cleft bone graft surgery are extremelyimportant to determine the success of the surgical procedure as itprovides adequate soft tissue for the closure over the bone graftwithout flap tension and dehiscence There are many flap designtechniques such as thelateral sliding flap, the oblique sliding flap,the buccal finger flap, the nasal lining flap and the palatal flap[18].The flap designs can be used by single or multipletechniques, depending on the clinical situation for optimaltension-free closure
1.2.3 The choice of donor site for graft material
Autogenous bone can be taken from many different sourcesinwhich the tibia is first used, followed by iliac crest, ribs, chin andcalvarial bone (SindetPerdersent and Enermark 1988) [116].Some authors have done a lot of research in order to replace theautogenousbone material in alveolar bone grafting,such as withdemineralized freeze-dried bone combined with iliac cancellousbone of Steven (2009) [121], β Tricalxium-phospate (TCP) ofRuiter (2012) [107] or BMP-2 (bone protein) of Dickinson (2008)
Trang 6[39] but studies using these materials is still not advancedand isnot commonly applied Therefore,autogenousgrafted bone is stillconsidered as the golden standard for graft material of alveolarcleft recovery.Ananth’s research (2005) summarized 110 centerswith 240 CLP surgical teams, which showed iliac crest bone isstill the most popularmaterial used by 83% [19].
1.2.4 Techniques of placing grafted bone
There are many techniques in placing the grafted bone in thecleft such as iliac crest cancellous bone graft [46], iliac crest boneblock graft [31], autogenous bone graftwithartificial membranebarriers covering graft material [100], the use of a cortex boneplate (CBP) along the lining of thepalatal suture line[85] andlateral corticalbone plates from the symphysis[127] But so far,these techniqueshave not been commonly used in alveolar cleftbone grafting
1.2.5 Evaluation methods of bone graft result
1.2.5.1 Means of evaluation
Some authors evaluate the results of bone graft by histology[60] but the most popular is still by computed tomography,including periapicalradiography, occlusalradiography, panoramicradiography, conventional CT and Cone Beam CT
The results of alveolar cleft bone graft was previouslymainlyassessed by periapicalradiography andocclusalradiography[46], [54], [55], [72], [81] but these films didnot measure the buccal-lingual distance of the graft [77].Therefore, Cone Beam CT today has become popular and useful
in assessing changes in volume and size in 3-dimension[59],[137]
1.2.5.2 Evaluation scale
Trang 7Figure 1.16:Enermark scale[42]
Nowadays, for the assessment of the alveolar bone graft outcome,most of thestudies usethe combination of two-dimensional film (periapicalradiography and
occlusalradiography) through the
evaluation scale of the bone
bridge formation in the cleftand
CTCone Beam to examine the
3-dimensional size or volume of the
graft [24], [26], [61], [79], [128],
[137] Several scales are applied
such asEnermarkscale (1987) [42], Berglandscale (1986) [24]using periapical radiographyand Kindelanscale (1997) [71] usingoccusal radiographyto assess the bone heightbetween the teeth inthe cleft areas, successful results was obtained when more than50% bone fill in the cleft areas (Figure 1.16)
Thesescales are popular because it is easy to apply incomparison with Long scale [81] and Witherow scale [140]
1.3 DENTAL IMPLANT
Osseointegratedimplant that was developed by professorBranemark in the 1960s has now becomeconventional treatmentmethod to restore the missing teeth as well as congenital teethdeficiency in CLP patients In 1991, Verdi [139] reported a firstcase of successful alveolar bone grafting and implant treatment,then followed by some reports of implant treatment in similarsituation as Fukuda (1998) [50], Kearns (1997) [68], Lilja (1998)[79], Takahashi [130], [131], Implants have the supportedfixationcomponent whichauthors have developed many flexiblesolutions for implant prosthesesfor various and complex situations
of CLP patients after alveolar cleft bone grafting However, most
Trang 8of the above studies have evaluated the success of implantosseointegration, not the aesthetic of implant prostheses.
Chapter 2: RESEARCH OBJECTS AND METHOD 1.1 Research subject
- Patient selection criteria: Patients over 15 years old, in goodhealth for endotracheal anesthesia, already has had palatoplasty,complete unilateral alveolar cleft, lack of permanent tooth germ inthe cleft andhas not had any alveolar cleft bone graft
- Elimination criteria: No alveolar cleft, no unilateral or bilateralalveolar cleft.Patientswho disagree to participate in the research
1.2 Research method
1.2.1 Research design:
This thesis useda prospective uncontrolled clinical trial method
to evaluate alveolar cleft bone graft outcomes and implantsuccess
Sample size: 32 patients by the averageestimating formula
1.2.2 Research time:August, 2010 to February, 2014.
1.2.3 Research procedure:
Firstly, patient information was collectedwith a case historyform After orthodontic and general dental treatment, alveolarcleft bone grafting surgery was conducted with the technique of 2iliac corticocancellousbone block autograft 4 to 6 months later,the implant placement was performed; 6 months later, prostheses
on the implant was executed.There was continued follow-up 15and 18 months after the alveolar cleft bone grafting
1.3 Surgical procedure
1.3.1 Iliac bone block harvesting surgery
A5cm incision over the superior iliac crestwas made 1 cm fromanterior superior iliac spine to prevent damage of the lateralfemoral cutaneous nerves Thesubcuticular structure and
Trang 9mucoperiosteumwas infiltrated and then dissection of theperiosteumwas carried out to expose iliac bone Ultrasonicpiezotome device was used to make 4 cuts: the first cut of 4cm onthe superior iliac crest away from the cortical bone in theabdominal cavity of 0.5cm, the second and the third cuts with thelength of 2cm were perpendicular to the first cut The fourth cutwas perpendicular to the second and the third cuts These fourcuts created a rectangle A chisel was used to harvest the boneblock including the cortical and cancellous bone with the size of 4
x 2 x 0.5cm3 Afterthat, hemostatic sponge was placed and 2 layersutures were used:periosteum suture and subcuticular suture Thebone blocks were kept in a small stainless steel cup in saline formoisture preservation
1.3.2 Alveolar cleft bone graft surgery:
Flap design: The incision began at the edge of the cleft and
wentover the cleft’s perimeter,divided the cleft into 2 parts, thenwent down to the alveolar crest, moved to the two sides oftheteeth’s neck next to the cleft and thencontinued to follow thegingival contours to the distalof tooth #4 or #5 and upwardto thevestibularforming avertical incision At the top of the vertical line,
an incision was made with the vertical line ofangle 120° to easilyslidethe flap to the lateral and downwardposition (Figure 2.28).After that, from the incision on the alveolar crest that stayedclosely to the neck (lateral) of the two teeth adjacent to the cleft,the incision was continued along the gingival sulcus on the labialside to the teeth at the two sides of the cleft
The nasal flap closure began with the suture from the buccal
to the labial at one side of the flap edge, then the dissection was
Trang 10Figure 2.32: The bone block on the vestibular was secured by screws Figure 2.33:
Wound closure Figure 2.31: The cleftwas nearly filled by cancellous bone
Figure 2.29:
Nasal flap closure
Figure 2.30: The bone block on the nasal lining
Figure 2.28: The incision for flap design on the vestibular
continued from the labial to the buccal at the contralateral flap
edge Finally, the knot was made (Figure 2.29)
Based on the bone grafting technique of two lateral cortical bone plates from the symphysisby Tadashi Mikoya(2010) [127],
we introduced two iliac corticocancellousblock graftingtechniques in this study with the technical steps as follows:
Step 1: Placement of cortical bone plate on the labial (nasal)aspects of the alveolar process defect: The iliac bone block was
cut into 2 blocks The first corticocancellous block with the size
of the cleft size was placed on the sutured nasal mucoperiosteum
(Figure 2.30) The cancellous bone was added on the plate until itnearly filled the cleft (Figure 2.31)
Step 2: The second corticocancellous block with a larger sizethan the cleft was placed on the grafted cancellous bone coveringthe whole cleft and secured by screws for a tight fixation(Figure
2.32)
Step 3: The wound closure: the palatalmucoperiosteumandthe vestibular mucoperiosteum wereclosedby
Trang 11the suture on the alveolar crest Vestibular mucoperiosteumwassutured onboth sides of the cleftfrom the ridge of the alveolarcrest towards thevestibular recess The suture was continuedtorecover the sulcus gingiva of the tooth from the cleft area Finally,mucosa closure was made with the vertical tension-freeincisionfrom the vestibular recess towards thealveolar crest (Figure 2.33).
1.3.3 Implant placement surgery and implant
prosthodontics
+ Implant placement in the aesthetic zone [29]: Using
implant surgical guide to ensure: Implant direction passes the occlusal edge of the further prostheses;In the buccal-lingual dimension, the buccal side of the implant is 2mm from the buccal side of the cortex;In the apical-coronal dimension, the implant shoulderis a distance of 3mm from the free gingival margin;In the mesial-distal dimension, the implant has a distance of at least
1.5mm from the next root
+ Prosthodontics: 6 months after the implant placement,secondary surgery of gum opening was carried outfor inserting thehealing screws, then 3 weeks later, the impression is done for theprosthodontics
1.4 Assessment criteria
1.4.1 Soft tissue condition at the recipient site
- Good: pink mucosa, dry, tight and healing scar
- Average: dehiscence but nograftexposure
- Bad: infection,dehiscenceorbone graftexposure
1.4.2 Oronasal fistula
- Closed: Clinical examination showed the fistula was closed
- Unclosed: Clinical examination showed the fistula still exists
Trang 121.4.3 Assessment of alveolar bone graft
- Assessment of bone bridge formation by periapicalradiography
Enermark scale was used for assessing bone formation in thecleft[42] according to 4 levels:
• Type I: 75% - 100% bone recovery compared to the initialbone graft site
• Type II: 75% - 50% bone recovery compared to the initialbone graft site
• Type III: 25% - 50% bone recovery compared to theinitial bone graft site
• Type IV: 0% -25% bone recovery compared to the initialbone graft site
Type I and Type II are considered successful Type III ispartial failure Type IV is completely failure
- Assessment of bone grafting result by CT Cone Beam
• The apical-coronal distance: marked as d, is measured
from the lowest point and the highest point of the grafted bone on
CT slices through the adiaphanouslocation axis on the surgicalguide
• The buccal-lingual distance: marked as r, is the average of
the apical-coronal distance of 1/3 superior (a), of 1/3 mesial (b)and of 1/3 inferior (c), r = (a+b+c)/3
• FollowingRenouard’s standard (1999): if the apical-coronaldistance is at least 7mm and the buccal-lingual distance is at least4mm then there isenable for implant placement [47]
Trang 131.4.4 Assessment of implant placement
- Assessment of the success of implant oseointegration byMisch’s criteria (2008) [89] included 4 levels:
o Success: if no pain in function, no clinical mobility isnoted, less than 2.0 mm of radiographicallycrestal bone loss isobserved compared with the implant insertion surgery, no history
of exudate
o Satisfactory survival: if they are stable, no observablepain and mobility in function, radiographic crestal bone loss isbetween 2.0 and 4.0 mm from the implant insertion
o Compromised survival: with no pain in function, nomobility, greater than 4mm radiographic crestal bone loss but lessthan 50% from around the implant, more than 7mm of probingdepths, often accompanied with bleeding
o Failure: if any of these conditions are presented: pain infunction, mobility, more than ½ implant length of bone loss,uncontrolled exudate, or has been surgically removed
- Assessment of the implant prosthesis’saesthetic:
+ Following pink esthetic score (PES) and white esthetic score(WES) based on Belser’s standard (2009) [23]: The pink estheticscore assesses the soft tissue condition around the implant through
5 factors compared to the contralateral tooth: mesial papilla, distalpapilla, curvature of the facial mucosa, level of the facial mucosa,and root convexity, soft tissue color White esthetic score presentsthe esthetic of the implant restoration with 5 parameters incomparison with the contralateral reference tooth: general toothform, volume of the clinical crown; color, surface texture andother characterization A maximum total score WES and PES ofmore than 12 was set for being esthetically successful, a score of
Trang 1412 for clinical acceptance and a score of under 12 forestheticalfailure
+ Assessment of the degree ofpatient satisfaction by thescore of 1 to 9 with a score of 1, 2, 3 for unsatisfactory, a score of
4, 5, 6 for satisfactory and a score of 7, 8, 9 for above satisfactory[43]
Chapter 3: RESEARCH RESULTS 3.1 Clinical characteristics of the study sample
- Total of 32 patients with the average age of 20.2 (15-29), 23females and 9 males in which 23 had left-side UCPL and 9 hadright-side UCLP 100% of patients presented with an oronasalfistulaand misalignment Therefore, all patients requiredorthodontic treatment with the average time of 12.5 months fortreatment
- The occlusion of Angle Class I was found in 53.1% patients,Angle Class III in 28.1% patients, the occlusion of cross bite, edge toedge or open bite in the anterior but Angle class I in the posterior wasreported in 18.7% Each patient had 9.8 decay on average
3.2 Result of alveolar bone graft
3.2.1.Mucosa condition of the recipient
At the follow-up 7 days postoperatively, 29 cases (90.6%)reported good healing A wound dehiscence occurred in threepatients (9.4%) resulting in a partial loss of bone, but the regionhealed uneventfully after exfoliation of small bone fragments.After 4 to 6 months, 100% of cases showed good healing
3.2.2.Result of alveolar bone graft
3.2.2.1.Result of bone formation usingEnermark scale