Skeletal, Dental and Soft Tissue Changes in Postural Class III Malocclusion Treated with a Maxillary Removable Appliance

Objective: This longitudinal retrospective cephalometric study was undertaken in an attempt to evaluate the effect of upper removable appliances on the hard and soft tissue structures in subjects with postural Class III.

Methods: The material consisted of cephalometric films of 17 Class III patients (8 females and 9 males, with a mean age of 10.10 ± 1.63). Each treated patient was matched before treatment with Class III subject for sex and age. Differences in treated group at T1 and T2 and between treated and untreated groups were examined using paired t-test and independent t-test respectively.

Results: Treated and untreated Class III subjects differed in mandibular prognathism (SNB, P<0.01). Upper incisors proclined and inter-incisal angle reduced during treatment (P<0.001). Soft tissue A point moved anteriorly as maxillary incisors were proclined (P<0.05). Soft tissue profile was improved (NNP, P<0.05; NAP, P<0.01).

Conclusion: Skeletal, dental and soft tissue changes were found in patients treated by upper removable appliance in postural Class III patients.

Clinical relevance: upper removable appliance is an efficient method to procline upper incisors in postural Class III malocclusion and may be of greater influence in improving soft tissue profile.

Class III; Malocclusion; Soft Tissue

1. 1- Major P W, Glover K. Treatment of anterior crossbite in early mixed dentition. J Can Dent Ass. 58, 574-575, 1992

2. Abu Alhaija E S J, Al-Khateeb S N, Al-Nimri K S Prevalence of malocclusion in 13-15 -year-old North Jordanian schoolchildren. Community Dental Health 22: 266-271,2005

3. Jenny J, Cons N C, Kohout F J, Frazier P J. Test of a method to deter mine socially acceptable occlusal conditions. Community Dentistry and Oral Epidemiology. 8: 424-433, 1980

4. Shaw W C, Meek S C, Jones D S. Nicknames, teasing, harassment and Salience of dental features among school children. Brit J Orthod. 7: 75-80,1980

5. Rakosi T, Schilli W. Class III anomalies: a coordinated approach to skeletal, dental and soft tissue problems. J. Oral Surg. 39: 860-870, 1981

6. Campbell P M The dilemma of Class III treatment. Angle Orthodont. 53: 175-191, 1983

7. Turley P K. Managing the developing Class III malocclusion with palatal expansion and facemask therapy. Am. J Orthod Dentofac Orthop. 122: 349-352. 2002,

8. Polson A M, Meitner S W, Zander H A. Trauma and progression of mar-ginal periodontitis in squirrel monkeys IV. Reversibility of bone loss due to trauma alone and trauma superimposed upon periodontitis. J Periodont Res. 11: 290-298. 1976

9. Hall-Scott J The maxillary-mandibular planes angle (MM) bisector: a new reference plane for antero-posterior measurement of the dental bases. Am J Orthod and Dentofac Orthop. 105: 583-591, 1994

10. Dahlberg G Statistical methods for medical and biological students. pp 122-132 London. George Allen and Unwin Ltd. 1940

11- Houston W J B The analysis of errors in orthodontic measurements. Am J Orthod. 83: 382-390 ,1983

12. Robinson S W, Speidel T M, Isaacson RJ,Worms F W. Soft tissue pro file change produced by reduction of mandibular prognathism. Angle Orthod 42: 227-235, 1972

13. Hershey H G, Smith L HSoft tissue profile changes associated with surgical correction of the prognathic mandible. Am J Orthod 65: 483- 502,1974

14. Rakosi T. The significance of roentgenographic cephalometrics in the diagnosis and treatment of Class III malocclusions. Trans eur orthodont soc, 155-170. 1970

15. Gravely J F. A study of the mandibular closure path in Angle Class III relationship. Brit J Orthod. 11, 85-91,1984