COMPRESSION Flashcards
(31 cards)
Compression
Transversal dental arch deviations
- Tooth-jaw deformation affecting dental arch’s width in transversal direction
- Assessed in sagittal plane
Compression
Main types of transversal dental arch deviations
- Compression
- Expansion
- Tremas and diastema in frontal segment
Compression
Prevalence of compression in primary and permanent dentition
- Compression=>less than 1% of cases in primary dentition
- 15% in permanent dentition, w/ maxilla most commonly affected
Compression
Different terms used to describe compression
- Compressio (Latin): Most commonly used term
- Endoalveolia: deformation affecting alveolar crest along w/ the teeth
- Endognathia: deformation affecting entire jaw
Compression
Compression classification based on affected structures
- Dento-alveolar compression (endoalveolia): Affects teeth and alveolar bone
- Skeletal (basal) compression (endognathia): Affects entire jaw’s bone structure
Compression
Different types of compression based on the number of affected jaws
- Compression of one jaw
- Bicompression (both jaws)
Compression
Categories of compression based on symmetry and affected regions
- Unilateral or bilateral (symmetrical/asymmetrical)
- Anterior or posterior compression
Compression
Primary etiological factors leading to underdevelopment of the dental arch and/or jaw
- Impaired nasal breathing
- Microglossia and short frenulum of tongue
- Hypodontia, premature extractions, and impacted canines
- Postoperative scars in upper jaw (e.g., after cleft surgery)
- Premature contacts (e.g., lower primary canines not abrading properly)
Compression
Factors causing compression due to external pressure
- Mouth breathing/impaired nasal breathing
- Bad habits, such as sleeping w/ hand or fist under cheek
Compression
General diseases contributing to compression
Avitaminosis and rickets
Compression
Clinical features of compression
- Extraoral=>
- No noticeable features
- In severe cases, face may appear long and narrow, w/ narrow nose
- Intraoral=>
- Changes in dental arch shape, tooth position, and palate shape/depth=>
- V-shaped, saddle-shaped, trapezoid form, deep or very deep palate
Compression
Disturbances associated w/compression
-
Occlusion disturbances=>
* Maxillary compression=>
* Posterior cross-bite, cusp-to-cusp bite, or distal bite
* Mandibular compression=>
* Lingual bite - Functional disturbances=> Impaired mastication, breathing issues, and speech problems
- Periodontal issues=>Improper alignment and occlusion of teeth
Compression
How compression diagnosed
- Clinical assessment
- Paraclinical assessment using cast models and radiography (e.g., teleradiography and OPG)
Compression
Aspects assessed using cast models in different dentition stages
- Primary dentition=>Dental arch shape/size, occlusion, and palate shape
- Mixed dentition=>Occlusion and Chateau Index
- Permanent dentition=>Dental arch size (Pont’s method) and apical base assessment.
Compression
Pont’s Analysis, use in compression diagnosis
- Measures width of dental arch=>
- PP (interpremolar width/anterior arch width)
- MM (intermolar width/posterior arch width)
- If measured distance less than normal, dental arch narrowed, indicating compression
Compression
How width of apical base and dental arch measured according to Apostolova and Dekova
- Maxilla=>
- Measure from deepest point of canine fossa from one side to other
- Mandible=>
- Measure 8 mm below line connecting necks of lower canine and first premolar
- Dental Arch Width=>
- Measured from middle of buccal cusp of first premolar, close to fissure
Compression
inference drawn from comparing apical base width with dental arch width
- If apical base width equals dental arch width + 1-2 mm=>
- Expansion possible
- If apical base width less than 0.5 mm wider than dental arch width in young patients=>
- Expansion possible
- If apical base width more than 0.5 mm narrower than dental arch width=>
- Expansion is not possible, and extraction necessary
Compression
Primary aim of treating compression
- Expand dental arch and jaw=>
- Proper conditions for alignment of the teeth
- Individually planned expansion for each segment of arch=>
- Ensure dental arch width corresponds to width of face
Compression
Ideal range for biological expansion of the dental arch in maxilla and mandible
- Maxilla: 5-6 mm
- Mandible: 3-4 mm
Compression
Characteristics of maxillary expansion in compression treatment
- Affects teeth, alveolar ridges, underlying bone, midpalatal suture, and palate
- Rapid palatal expansion requires time for ossification of midpalatal suture
- Maxillary expansion leads to vestibular inclination of molars and prolapse of palatal cusps, causing bite opening
- Treatment may be complicated if maxillary apical base width smaller than dental arch width, w/ risk of relapse
Compression
Characteristics of mandibular expansion in compression treatment
- Expansion mainly achieved by vestibular inclination of the teeth rather than suture opening
- Mandibular apical base large=>
- Dental arch expansion less problematic
Compression
When treatment for compression initiated in primary dentition
- When compression disturbs occlusion (e.g., cross-bite)
- When prevents or stops development of upper jaw=>
- Maxillary compression combined w/ retrusion or mandibular deviation
Compression
Appliances used for treating compression in primary dentition
- Preventive and therapeutic
- Myogymnastics for tongue commonly used in primary dentition
Compression
Most suitable time to treat compression in mixed dentition
- When roots of posterior primary teeth not yet resorbed
- Germs of permanent teeth move simultaneously w/ primary teeth
