INDIAN DENTAL ACADEMY
Leader in continuing dental educationwww.indiandentalacademy.com
Dr. K. Praveen KumarPG
Narayana Dental college & Hospital
AJODO - JANUARY 2008;133:30-7
DENSITY OF THE ALVEOLAR AND BASAL BONES OF THE MAXILLA
AND THE MANDIBLEby
Hyo-Sang Park, Youn-Ju Lee, Seong-Hwa Jeong
To investigate and evaluate the density of the alveolar and basal bones of the maxilla and the mandible.
WHY - DENSITYIT DETERMINES
TREATMENT PLANNINGIMPLANT DESIGNSURGICAL APPROACHHEALING TIMEINITIAL PROGRESSIVE BONE LOADINGSUCCESS RATE
LEONARD LINKOW (1970)
CLASS – I : Ideal bone type with evenly spaced
trabeculae and small cancellated spaces.
CLASS – II : Slightly larger cancellated spaces with less
uniformity of the osseous pattern.
CLASS – III : Large marrow filled spaces exist between
LEKHOLM AND ZARB (1985)
QUALITY – I : Homogenous compact boneQUALITY – II : Thick layer of compact bone
surrounding a core of dense trabecular
bone.QUALITY – III : Thin layer of cortical bone
surrounding dense trabecular bone of
favorable strength.QUALITY – IV : Thin layer of cortical bone
surrounding a core of low density trabecular
D1 bone – >1250 HU. ( DENSE CORTICAL)
D2 bone – 850 – 1250 HU ( POROUS CORTICAL)
D3 bone – 350 – 850 HU ( COARSE TRABECULAR)
D4 bone – 150 – 350 HU ( FINE TRABECULAR)
D5 bone – <150 HU ( SOFT)
ADVANTAGESTo overcome problems associated with anchorage
Easy placement and easy removal.
Minimal anatomical limitations of their small size.
Low cost compared with other skeletal anchorage options.
No patient compliance.
DISADVANTAGESDisplacement on loading.
Threatens adjacent dental roots or vital organs.
INDICATIONSEn-masse retraction of the Anterior and posterior
Retraction of the whole dentition.
Protraction of molars.
Forced eruption of the canines.
Lingual orthodontic treatment.
CONTRAINDICATIONSAbsolute contraindication: Severe systemic disorder, eg: osteoporosis. Psychiatric diseases, eg: psychoses
dysmorphobia. Alcoholics drug abusers.
Relative contraindications: Insufficient volume of bone Poor bone quality Patients undergoing radiation therapy Insulin dependent diabetes Heavy smokers
IMPLANT TYPES – ORTHODONTICS
MOST RECOMMENDED SITESMid palatine area.The alveolar bone between the maxillary 2nd
premolar & molar.The Mandibular 1st and 2nd molars.
OTHER POSSIBLE SITESRetromolar area.The chinThe inferior ridge of the piriform
aperture(ANS).The inferior ridge of the Zygomatic archThe maxillary tuberosityThe mandibular body
FACTORS AFFECTING SUCCESS
HOST – BONE DENSITY
IMPLANT – SIZE, SHAPE, SURFACE, COMPOSITION
SURGICAL METHOD – OPEN – CLOSED METHOD
METHODSMANUAL BONE MAPPING
RADIOGRAPHIC IOPA ORTHOPANOGRAM LATERAL CEPHALOGRAM
IMAGING COMPUTER TOMOGRAM SCANNING ( CT- SCAN
MATERIALS AND METHODSSAMPLE SIZE - 63 23 Men (Ages, 29 ± 10.9) 40 Women (Ages, 25.6 ± 7.6)
63 sets of CT images were collected
V-WORKS IMAGING software (Cybermed, Seoul, Korea)
STATISTICAL ANALYSISSAS software (version 8.01; SAS, Cary, NC).
Combined sample was used for the statistical analysis as there was no no difference between Men and Women.
1 way analysis of variance (ANOVA) is performed to analyze differences of bone density at the incisor, canine, premolar, molar, retromolar and tuberosity areas in the maxilla and the mandible.
Tukey multiple range test was used for multiple comparisons.
The Student ‘t’ test is used to evaluate differences between the alveolar and the basal bones, and the difference between the maxilla and the mandible.
Error possibilitiesTo calculate the errors of measurement, 69
randomly selected measurement sites were measured 1 month later.
The measurement error was calculated based on the differences between the first and second measured values with the paired ‘t’ test.
There was no significant difference between the two measurements according to Dahlberg’s formula.
RESULTSMAXILLA – BASAL AND ALVEOLAR ( CANCELLOUS BONE ) The overall bone density between 280 – 500 HU Except for the lowest in the tuberosity area 151 HU
MAXILLARY ALVEOLAR BONE ( CORTICAL BONE )The overall bone density between 810 – 940 HU EXCEPT for maxillary tuberosity – 443 HU (Buccal
cortical). - 615 HU (Palatal
cortical).MAXILLARY BASAL BONE ( CORTICAL BONE )The overall bone density between 835 – 1113 HU EXCEPT for maxillary tuberosity – 542 HU
MANDIBULAR ALVEOLAR BONE ( CANCELLOUS BONE ) The overall bone density between 300 – 500 HU MANDIBULAR BASAL BONE ( CANCELLOUS BONE ) The overall bone density between 170 – 440 HU
MANDIBULAR ALVEOLAR BONE ( CORTICAL BONE ) The overall bone density between 810 – 1580 HU MANDIBULAR BASAL BONE ( CORTICAL BONE ) The overall bone density between 1320 – 1560 HU THE RANGE INCREASED GRADUALLY FROM INCISOR
TO RETROMOLAR AREA.
DISCUSSIONJaffin and Berman reportd, implant failure rate was 3% for type – 1, 2, 3 bone densities 35% for type – 4 bone density( According to Lekholm and Zarb bone quality
Truhlar etal concluded that failure rate was Q1>Q2>Q3
Placement of implants in D1 bone was less successful than D2 and D3 bones.
Comparisons of densities between alveolar and basal bones of the mandible ( *P < 0.05 ).
Comparisons of density between maxillary and mandibular alveolar bones (*P <0.05 )
Comparisons of bone density of the paramedian area at the canine and molar of the buccal alveolar and basal bones
Cancellous bone did not show much difference between the maxilla and the mandible.
Cortical bone in the maxilla is much thinner and less dense than in the mandible.
CONCLUSIONBasal bone generally showed higher density
than that of alveolar bone.
Cortical bone of the mandible was denser than that of the maxilla, where as cancellous bone had similar densities between the mandible and the maxilla with some exception.
These data could provide valuable information when selecting sites and choosing placement methods for mini screw and micro screw implants.
REVIEW OF LITERATUREThe normal human/primate craniofacial skeleton,
including the mandible, is known to grow in a symmetric
manner bilaterally with complex interactions between
specific growth sites and local remodeling.(AJO-D,1988 Feb).
Skeletal anchorage system for open bite correction – Umemori M, Sugawara J, Mitani H, AJODO 1999 ; 115: 166-74.
The possibility of skeletal anchorage – Creekmore TD, JCO 1983; 17: 266-69.
Micro-implant anchorage for treatment of skeletal class I bialveolar protrusion – Park HS, Bae Sm, Kyung HM, JCO 2001; 35: 417-22.
The efficient use of midpalatal mini screw implants – Lee JS, Kim DH, Park YC, Kyung SH, AO 2004;74:711-14.
A density comparison of human alveolar and retromolar bone – Buck DL, Wheeler PW, AO 1969; 39: 133-36.
Craniomandibular morphology with computed tomography - Miller, Cann, Nielsen, and Roda (AJO-DO), Volume 1988 Feb (117 - 125).
Factors affecting the clinical success of screw implants used as orthodontic anchorage – Park HS, Jeong SH, AJODO 2006;130:18-25.
The effect of altered bone metabolism on orthodontic tooth movement - Midgett RJ, Shaye R, Fruge JF AJO 1981; 80: 256-62.
Temperatures measured in human cortical bone when drilling – Matthews LS, Hirsch C, J Bone Joint Surg Am 1972;54:297-308.
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