Class 1 malocclusion by almuzian

883 views

Published on

0 Comments
3 Likes
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total views
883
On SlideShare
0
From Embeds
0
Number of Embeds
2
Actions
Shares
0
Downloads
109
Comments
0
Likes
3
Embeds 0
No embeds

No notes for slide

Class 1 malocclusion by almuzian

  1. 1. UNIVERSITY OF GLASGOW, 2013 Class I Malocclusion . Dr.Mohammed Almuzian 1/1/2013 .
  2. 2. 1 UNIVERSITY OF GLASGOW, 2013 Table of Contents Definition..................................................................................................................................................2 Prevalence.................................................................................................................................................2 Etiology.....................................................................................................................................................3 Features of class I malocclusion ...............................................................................................................3 1. The skeletal pattern...........................................................................................................................3 2. The soft tissues..................................................................................................................................3 3. Growth ..............................................................................................................................................4 4. Path of Closure..................................................................................................................................4 5. Occlusal Features..............................................................................................................................4 The treatment of Class I malocclusions may involve any treatment of the following occlusal traits...........5 Principles of treatment in class I malocclusions .........................................................................................11
  3. 3. 2 UNIVERSITY OF GLASGOW, 2013 Class I Malocclusion Definition 1. Class I malocclusion is defined as that malocclusion in which the lower incisors occlude on or directly beneath the cingulum plateau of the upper incisors (BSI 1983). 2. The upper incisor inclination is average and the overjet is 2–3 mm. 3. The anteroposterior relationship is normal, but there may be  Vertical malrelationships of the jaws or teeth  Transverse malrelationships of the jaws or teeth  Intra-arch malocclusion. Prevalence 1. Houston et al.1992 quoting Foster and Day (1974) gave the percentages of the various malocclusions in a UK population as follows:  Class I malocclusions (44%)  Class II division 1 (27%)  Class II division 2 (17%)  Class III (3%)  Class II Indeterminate (9%). 2. Jones and Oliver 2000  Class I malocclusions (50%)  Class II division 1 (25-33%)  Class II division 2 (7-10%)  Class III (3-5%)
  4. 4. 3 UNIVERSITY OF GLASGOW, 2013 Etiology It could be classified into:  Genetic like in vertical height problem, microdontia, missing teeth  Environmental like habit, pathological, traumatic and premature loss of primary teeth. Another classification is:  Skeletal  Soft tissue  Dentoalveolar  Habit Features of class I malocclusion 1. The skeletal pattern  It is usually class I; with any variation from this being generally mild class II or III anteroposterior.  Bimaxillary prognathisim (where both cephalometric angles SNA and SNB are increased but ANB is within the normal range) can occur in Class I malocclusion.  VH or FMPA reduced or increased  Frontal view show wide variation of anomalies and could be symmetrical or asymmetrical. 2. The soft tissues  Mesoproscopic facial types in profile view.  Generally favorable and rarely have a significant influence on the malocclusion,
  5. 5. 4 UNIVERSITY OF GLASGOW, 2013  Lip could be incompetence associated with an increased lower face height and anterior open bite.  Bi-maxillary proclination may occur in association with lip protrusion. 3. Growth  Growth of the jaws is usually favorable, with the incisor relationship being maintained.  There is a tendency for the mandible to become slightly more prognathic with age, and a mild Class II relationship will tend to improve with time. 4. Path of Closure  The path of closure is usually direct and unless there are premature occlusal contacts, there will be no deviations or displacements.  However, these should be checked for during the clinical examination of the patient, as an apparent Class I malocclusion in centric occlusion may be very different to that in centric relation (which is the maximum retruded contact position of the teeth). 5. Occlusal Features 1. Class I incisor relationship 2. OJ is within the normal range, although cases of bi-maxillary proclination can have a class I incisor relationship with an increased overjet or even slightly reduced overjet. 3. Molar and canine relationship variable from class 1 to class 3 4. OB either  Increased overbite. A markedly increased overbite is incompatible with the definition of a class I incisor relationship and is more in the domain of a
  6. 6. 5 UNIVERSITY OF GLASGOW, 2013 class II division 1 or a class II division 2 malocclusion. Sometimes this may be referred to as a ‘deep bite Class I occlusion’.  A frank anterior open bite with an associated increase in the lower face height. 5. Arch length feature either aligned, dental crowding or spacing 6. Posterior unilateral or bilateral crossbite or scissor bite can be associated with digit sucking or a skeletal discrepancy and facial asymmetry. 7. Bimaxillary proclination is where both the upper and lower incisors are proclined, and the proclined upper incisors will automatically have an increased overjet even if the lower incisors occlude with the middle third of the palatal surface of the upper incisors. The treatment of Class I malocclusions may involve any treatment of the following occlusal traits 1. Tooth size/alveolar bone discrepancy (crowding) Space being created by  Distalization of molars by HG or lip pumper, Cetlin and Ten Hoeve, 1983. Recently the Enmass retraction or distalization of the upper arch on non-extraction base using TADs has been widely used in the literature. Betchtold and Kim 2013.  Inter-proximal reduction, Sheridan, 1985  Arch expansion and lengthening. However, excessive lower arch expansion or proclination of the lower incisors should generally be avoided as this is inherently unstable (Ackerman and Proffit, 1997).  Utilization of the Leeway space, Brennan and Gianelly, 2000  Extraction of teeth. In severe crowding the extraction of teeth is usually required. Serial extraction at early stages might be indicated
  7. 7. 6 UNIVERSITY OF GLASGOW, 2013  Combinations. 2. Variations in tooth numbers (congenitally absent, supernumeraries, supplemental) Treatment for missing teeth could be  Accept  Restorative option  Open space option  Close space option Treatment for supernumerary teeth could be  leave it and monitor  extract with or without orthodontic treatment 3. Variation in tooth size &shape (Macro-/microdont teeth, Accessory cusps Dens in dente, Fusion, Gemination, Concrescence, Morphological problems (e.g. dilacerations) Treatment for Macrodeont  No treatment  Inter-Proximal Stripping (moderate cases)  Composite build up and reshaping or veneer reshaping  Intentional extraction, then space can be closed or used for malocclusion correction or can be replaced by any methods.  Any of the above with orthodontic treatment Treatment for Microdeont  No treatment
  8. 8. 7 UNIVERSITY OF GLASGOW, 2013  Composite build up and reshaping or veneer reshaping  Intentional extraction, then space can be closed or used for malocclusion correction or can be replaced by any methods. (RBB, fixed bridge, removable, implant, autotransplanation)  Any of the above with orthodontic treatment 4. Variation in tooth position, Impactions  No treatment, observe and monitor  Interceptive treatment  Surgical removal  Surgical exposure and orthodontic alignment  Transplantation, Moss, 1974  Sectional osteotomy and Surgical repositioning 5. Crossbites & Scissors bite Anterior cross bite A. if dental cross bite then  Bodily movement  use fixed appliance 2*4 appliance  Simple tipping movement  use URA with posterior capping, Z spring, double cantilever spring, crossed cantilever spring, screw plate B. Dentoalveolar or mild skeletal cross bite then  Chincap  Frankle 3 (Functional) Treatment of post crossbites with displacement (Harrison and Ashby, 2001 Cochrane)  Encourage habit to stop
  9. 9. 8 UNIVERSITY OF GLASGOW, 2013  Posterior onlay  Studies support grinding as treatment in the primary dentition. Selective grinding of the c or extraction if it is associated with severely displaced single tooth  expand upper arch with: A. if teeth not tilted buccally  URA with midpalatal screw, success rates is 50%  Coffin spring + posterior capping,  Quad. (QH and RME success rates is 100%) B. If already compensated - RME (There appears to be no difference in the amount of expansion of the back teeth obtained when using a banded or bonded rapid maxillary expansion brace. Harrisson, Cochrane 2008) C. Fixed appliances incorporating expanded heavy stainless steel archwires will result in expansion of the dental arch. D. Cross-elastics E. an auxiliary buccal arch constructed from 0.9-mm steel can be placed in the molar headgear tubes and expanded Unilateral Crossbite with No Displacement: • Correction is seldom indicated Bilateral Crossbite • Usually there is no displacement no functional indication for treatment • Best treated with RME but you do get a lot of relapse so overcorrect Posterior mand displacement This associated with cl2 d2 and better to be treated ASAP to avoid TMJ problem 6. Early loss of deciduous teeth (space loss, centreline shifts) Space management
  10. 10. 9 UNIVERSITY OF GLASGOW, 2013  Balancing & Compensating Extractions  Space maintenance  Space regaining  Management of Lee way space 7. Retained deciduous teeth, submergence, ankylosis, ectopic eruption of successors) Management of ankylosis deciduous teeth  In the presence of a permanent successor and minimal infraocclusion, the ankylosed tooth can usually be left under observation to exfoliate naturally. If the infraocclusion becomes greater this can lead to displacement, tipping and overeruption of adjacent teeth. In these circumstances, consideration should be given to either restoring the vertical dimension or extracting the affected tooth with lingual or palatal arch to maintain the space.  In the absence of a permanent successor, the Treatment options, A. The early Extraction to facilitate spontaneous space closure. It is better to allow permanent teeth to drift into the edentulous space and bring bone with them, and then reposition the teeth prior to implant or prosthetic replacement, so that large periodontal defects do not develop. B. Premolaizing the E by slicing and space closure C. Extraction and prosthetic replacement; D. Retention of the second deciduous molar. Treatment options for ectopic maxillary molars, Kennedy 1987 a. If resorption of E <1.5mm: • observe 3-6mths (to establish if reversible) • if no resorption and vertical position improved: monitor eruption
  11. 11. 10 UNIVERSITY OF GLASGOW, 2013 • if no resorption and vertical position not improved: expose unerupted 6 and wait for 3 months • If still <1.5mm resorption: treatment to move the impacted tooth distally. b. If resorption of E >1.5mm: • If E symptomatic or mobility >1mm consider Xtn and management of space problem once 6 erupts • If E asymptomatic and mobility <1mm and 6 partially erupted: treatment to move the impacted tooth distally •If E asymptomatic and mobility <1mm and 6 unerupted: expose 6 and commence treatment to move the impacted tooth distally Management of impacted and ankylosed teeth include: (Urebi 2013) • Extraction of the ankylosed tooth followed by prosthetic replacement. • Surgical luxation of the tooth followed by orthodontic traction. • Surgical luxation followed by periodontal ligament distraction. • Osteotomy of the dentoalveolar segment with immediate repositioning of the dentoalveolar structures. • Osteotomy followed by intraoral distraction. • Osteotomy followed by heavy orthodontic forces. • Osteotomy followed by a combination of dentoalveolar distraction and light orthodontic forces. • Osteotomy followed by conventional orthodontic forces. • Osteotomy with partial repositioning followed by heavy orthodontic forces. • Lingual corticotomy of the dentoalveolar segment, followed by a labial corticotomy three weeks later and a conventional orthodontic force. 8. Premature loss of permanent teeth 9. Eruption anomalies (variation in eruption sequence).
  12. 12. 11 UNIVERSITY OF GLASGOW, 2013 10.Vertical discrepancy including AOB and deep OB. Principles of treatment in class I malocclusions 1. Relief of crowding 2. Alignment and leveling 3. Normal OJ and OB 4. Normalization of buccal segements relationships 5. Space closure. 6. Arch coordination. 7. Detailing of the occlusion

×