Cephalometric Evaluation of Maxillary Retrognathism Cases Treated with Fr-3 Appliance

Pakistan Oral & Dent. Jr. 22 (1) June 2002

CEPHALOMETRIC EVALUATION OF MAXILLARY RETROGNATHISM CASES TREATED WITH FR-3 APPLIANCE

*M WAHEED-UL-HAMEED BDS, MCPS, MS (Orthodontics)

ABSTRACT

The purpose of this evaluation was to evaluate the efficiency of FR-3 appliance on functional class- 3 malocclusion cases. A total of 20 functional class-3 cases were chosen from a general clinic intake. 10 of the 20 cases formed the treatment group while 10 untreated patients were taken as a control group. Patients that were treated with FR-3 had the following characteristics. Class-3 with maxillary deficiency, Functional anterior X-Bite, Absence of anterior open bite and Patients in mixed dentition

The mean age in treatment group was 8.7 ± .047 years and 8.74 ± 1.65 years in the control group. The observation period was one year for both groups.

The results were as follows,

Sagittal forward growth stimulation was not observed in maxilla Mandibular growth was redirected in vertical direction The SNB angle decreased in that mandible rotated downward and backward The ANB angle increased

There was an increase in total and lower anterior facial height and reduction in the overbite. Another skeletal change observed was the increase in the cranial flexure angle. Improved dental results were a significant amount of overjet increase and decrease in IMPA. There was also a beneficial effect on the soft tissue profile.

Key words: Frankel appliance, FR-3, functional regulator 3, Cl-3

INTRODUCTION Due to non-applicability of X-Rays for the treatment purpose, diagnosis of Class-3 malocclusion had The mandibular prognathism has been found to been a big problem. The maxillary retrognathism as a draw much attention of human being throughout cause of Class-3 malocclusion was first diagnosed the history. One of the proofs is the figures of after the invention of Cephalostate2. Cellier in France prognathic faces found in the art work left by and Fox in America did the first chin cap application Egyptians and Greeks. The book written by John in the beginning of 19th century for the treatment of Hunter in 1778 named "The Natural History of Class-3 malocclusion3. With the discerning of the fact, Human Teeth", explains the awareness about maxillary retrusion as a cause of Class-3 malocclu- prognathism even at that time'. sion, development of appliance for maxillary protrac- In some societies prognathic lower jaw was a tion was started. Delaire face mask and his modified 4 symbol of nobility. The reason for this was that appliances were used for this aim. the people of Hapsburg family from Austria had In 1970 a new appliance was introduced by Rolf this anomaly. Frankel who advised the use of FR-3 appliance in the

* Assistant Professor & Head of Orthodontic Department, de'Montmorency College of Dentistry, Lahore.

25 treatment of Class-3 malocclusion characterized by The patients were observed over a period of one maxillary retrusion5. Even now a days Frankel appli- year. All cases in the study and control group were ances are widely used in most of the clinics. in the mixed dentition period. They had the following According to Frankel if one does not take the characteristics: CI III with maxillary deficiency, func- advantage of growth, the ultimate treatment may be tional anterior cross-bite and the absence of anterior the surgery after the growth is over. open bite.

He recommended the use of function corrector in Measurements were obtained by lateral cephalo- mixed dentition or early permanent dentition. The metric radiography of patients before treatment and therapeutic principle underlying the use of function after one year. regulator-3 consists of eliminating all the factors, The SN plane was used as a reference for sagittal which may impede maxillary development, and at the registrations. This plane was transferred from the same time in preventing mandibular development. first cephalogram to the second by SN registration In the literature there are many articles about superimposing on point S. the treatment of Class-3 malocclusion with 6,7,8,9,10,11,12,13,14,15,16 For the purpose of this study 18 skeletal, 11 dental FR-35. measurements were made on each cephalogram. These measurements were as follows: Most of these are case reports. Only five articles about the statistical investigations could be Skeletal Measurements found6,17,18,19,20. In most of these cases there was not a control group. In two of them changes in Class-3 Skeletal Angular Measurements malocclusion were compared with changes in class-2 1- SNA 2- SNB 3- ANB Div-1 group6,18. In one of these studies the changes obtained by Class-3 therapy were compared with the 4- SN-PoG 5- S-N/Go-Gn 6- FMA changes in a control group of mixed dentition18. 7- Y-Axis 8- N-S-Ar 9- S-Ar-Go Only in one study, the changes in class-3 maloc- 10- Ar-Go-Me 11- Sum of inner angles clusion were compared with class-3 control group20. 12- Ar-Go-N 13- N-Go-Me The effectiveness of FR-3 appliances controversial and very less information is available regarding the Skeletal Linear Measurements effects of orthopedic treatment in class-3 malocclusion. 1- Witts value 2- N-Me 3- ANS-Me

So the aim of our study is to evaluate the real U1-SNGU1-FHeU1-FHNS-Me/N-Me effectiveness of FR-3 appliance in class-3 malocclusion by comparing the treatment changes Dental MeasuremenU1-U1-Ll with an untreated class-3 control group. Dental Angular Measurements

MATERIALS AND METHODS 1- Ul-SN 2- Ul-FH 3- U1-NA 4- L1-NB 5- L1-Go-Gn 6- Ul-Ll angle The study material comprised 20 patients from our clinical intake. Two groups were selected; the first Dental Linear Measurements group of 10 patients was treated with the Frankel appliance and the other 10 patients taken as a control 1- NA(mm) 2- L1-NB(mm) 3- Overjet group. 4- Overbite 5- L1-A-Pog Five of the FR-3 group was girls and five were Statistical Method: Data was a first classified ac- boys. Their ages ranged from 7.6 to 8.9 years cording to sex. However as there was no significant (mean age 8.7). difference b/w boys and girls and the numbers were In the control group 5 were boys and 5 were girls. small so the final analysis was made on the combined Their ages ranged from 7.5 to 9.1 years (mean 8.74). group.

26 In this study non-parametric tests were used for appliances in patients of this age4, 21, 23 and others statistical evaluation. The Wilcoxon test was used for deferred treatment until the patient is mature and each group and the Mann-Whiteny U test used to then treating them with surgical procedures24, 25, 26. compare the difference between the control and treat- Frankel suggested a new functional concept, different ment groups (table 1-3) from the other types of functional therapy, the essen- tial aim of his appliances being to correct the func- Dahlberg's method was used for the calculation of tional disorders. In our study the FR-3 had a 4 the operator's random error . beneficial effect on CI III malocclusion and the 10 cephalograms were selected at random from appliance used was made as described by Frankel 8,27,28 the total of 40 available and these were measured and McNamara . The age range in the FR-3 and the control group was 7-9 years being the age range twice by the same investigator (table-4). recommended by Frankel for such treatment. The formula being Evaluation of Skeletal Changes

Over the duration of the study there were statistically significant improvements at the SNA angle in Sm = the Dahlberg's method error the Frankel and control groups. However there was a d = the difference between two measurements non-significant difference between these groups. From n = number of patients this finding we suggest that FR-3 was not effective on point A. Many investigators reported the same re- sults5,17,27,28. However Frankel6 reported significant changes in maxillary anteroposterior growth potential which we believe may be due to the use of CI- II Q = the actual method error patients as a control group as against a CI- II experi- X = n degrees of freedom mental group.

RESULTS The SNBSm/gle decreased (p>0.01) significantly in the FR-3 group but not in the control group and Table 1 shows the skeletal and dental changes there was a significant difference between groups. The of the control group. These changes are non ANB angle increased (p>0.01) showing the efficiency of significant statistically. the FR-3 appliance to have no effect on the mandibular body and that the change in the sagittal Table 2 shows the skeletal and dental changes growth pattern was translative. of the FR-3 group. Skeletal measurements SNB, ANB, Y-Axis and ANS-Me/N-Me changed The S-N/Go-Gn, Y-Axis and Na-Me, ANS-Me mea- significantly. Significant dental measurements were surU1-SN, increased significantly indicating that the Ul-SN, U1-NA, L1-NB, IMPA, Ll-NB mm, L1-Apog FR-3 appliance increased this vertical 'growth pattern, mm and overjet also confirming previous work by many au- thors10,19,29,30. Table 3 shows the statistical evaluation of the cephalometric changes in the control and the FR-3 The cranial flexure angle increased significantly group and the comparison of the two groups. When (p>0.01) in the FR-3 group, but not in the control the two groups were compared, the skeletal group and no statistically significant difference was measurements of SNB, ANB, Y-Axis, ANS-Me/N-Me found between groups, Kerr, Ten, HU1-NA,d showed significant changes. The dental McNamara18 also reported an increase in this angle measurements UlSN, Ul-NA, IMPA, Ll-NB and overjet with the FR-3 appliance. changed significantly. Evaluation of Dental Changes DISCUSSION The I-S angle, I/N-A angle and I/N-A CI III malocclusions always provided major prob- measurement did not change significantly, thus it lems for the clinician. Some prefer to use extra- oral appears that the FR-3 did not affect the upper central teeth. 27 TABLE 1. SPONTANEOUS SKELETAL & DENTAL CHANGES IN THE CONTROL GROUP (n=10) SKELETAL CONTROL GROUP n = 10 Before Control After Control Difference W-Test Skeletal Angular Measurements Mean Sd Mean Sd Mean Sd Prob SNA 80.6 1089 80.95 2.44 0.35 1.9 0.69 SNB 82.35 2.29 82.2 2.6 -0.15 2.06 0.51 ANB -1.75 1.25 -1.25 1.03 0.5 1.17 0.23 SN-Pog 82.25 2.04 82.75 2.60 0.5 2.19 0.85 SN-Go-Gn 33.25 3.76 33.1 3.81 -0.15 2.16 0.76 FMA 24.45 2.45 25.25 3.73 0.8 3.22 0.38 Y-Axis 56.65 2.46 57.75 2.74 1.2 2.69 0.16 Inner Angles 392.75 4.06 395.1 6.64 2.35 5.66 0.35 Gonial Ratio 72.90 8.11 71.42 6.74 -1.48 4.31 0.37 Skeletal Linear Measurements Witt, S -5.5 1.89 -5.55 2.16 -0.05 2.03 0.86 N-Me 111.3 5.20 111.2 5.41 -0.1 3.57 0.58 ANS-Me 61.2 2.09 61.7 2.71 0.5 1.84 0.4 Jaraback Ratio (S-Go/N-Me) 64.36 5.30 65.62 3.86 1.06 4.00 0.44 Facial Ratio ANS-Me/N-Me 55.05 2.30 55.52 1.86 0.47 3.00 0.76 CONTROL GROUP DENTAL MEASUREMENTS Before Control After Control Difference W-Test Angular Measurements Mean Sd Mean SD Mean Sd Prob U1-SN 105.1 5.14 105.25 6.86 0.15 5.38 0.35 Ul-FH 113.7 4.37 113.6 5.45 -0.1 3.23 0.94 Ul-Ll Angle 132.2 11.38 133 9.55 0.8 3.04 0.59 U1-NA 24.05 5.11 24.6 7.77 0.55 5.12 0.72 Ll-NB 24.35 6.78 32.1 6.27 -1.25 3.90 0.32 IMPA 85.9 4.88 84.75 4.96 -1.15 4.34 0.33 Linear Measurements U1-NA (mm) 3.75 1.23 3.95 1.67 0.20 1.26 0.59 L1-NB (mm) 3.55 1.88 3.3 1.79 -0.20 1.03 0.47 L1-Apog (mm) 3.7 1.90 3.85 1.94 -0.05 0.92 0.39 Overjet (mm) -1.25 1.29 -1.1 1.17 0.2 0.91 0.91 Overbite 1.3 1.18 0.7 1.31 -0.6 0.80 0.40* P < 0.05* P < 0.01*** P < 0.001***

TABLE 2. THE SKELETAL & DENTAL CHANGES IN THE TREATMENT GROUP (n=10) SKELETAL TREATMENT GROUP Before Treatment After Treatment Difference W-Test Skeletal Angular Measurements Mean Sd Mean SD Mean Sd Prob SNA 79.35 2.24 80.3 1.98 0.95 1.60 0.08 SNB 79.6 2.41 78.9 2.69 -0.7 0.91 0.04* ANB -0.25 1.03 1.4 1.98 1.65 1.39 0.01** SN-Pog 79.95 2.85 79.7 3.35 -0.25 1.11 0.40 SN-Go-Gn 37.3 3.47 37.25 3.16 -0.05 1.16 0.94 FMA 27.8 4.53 28.45 3.54 0.65 1.94 0.31 Y-Axis 57.4 3.98 59.65 3.14 2.2 2.12 0.01** Inner Angles 396.85 3.15 398.65 3.03 1.8 3.22 0.12 Gonial Ratio 69.69 5.17 69.33 4.87 0.63 2.4 0.61 Skeletal Linear Measurements Witt, S -4 2.50 -2.95 3.32 1.05 1.96 0.14 N-Me 114.2 6.76 114.9 5.15 0.7 3.65 3.34 ANS-Me 62.1 6.62 64.6 4.74 1.9 6.63 0.09 Jaraback Ratio (S-Go/N-Me) 60.69 2.16 61.57 2.75 0.84 2.26 0.26 Facial Ratio ANS-Me/N-Me 54.27 2.94 55.66 2.41 1.44 2.21 0.05*

(Continued)

28 TREATMENT GROUP (DENTAL MEASUREMENTS) Before Treatment After Treatment Difference W-Test Angular Measurements Mean Sd Mean SD Mean Sd Prob Ul-SN 101.35 6.14 105.4 7.77 4.45 5.77 0.05* Ul-FH 110.75 5.46 113.4 6.26 2.65 5.07 0.10 Ul-L1 Angle 132.9 5.58 131.5 5.81 -2.8 6.37 0.44 Ul-NA 20.8 5.22 25.55 6.52 6.35 4.93 0.05* L1-NB 25.45 3.70 21.00 4.45 -4.45 3.39 0.01** IMPA 89.3 4.73 86.15U1- 4.36 -3.25 3.12 0.01** Linear Measurements U1-NA (mm) 2.95 1.57 4.05 2.26 1.1 2.89 0.28- Ll-NB (mm) 4.5 1.87 3.00 1.58 -1.45 0.86 0.01** Ll-Apog (mm) 4.4 1.82 2.3 1.71 -2.1 1.02 0.01** Overjet (mm) -1.8 1.41 1.85 1.88 3.65 1.51 0.01** Overbite 1.49 -0.65 1.49 0.28 1.15 0.5 0.97 P < 0.05* P < 0.01*** P < 0.001*** TABLE 3. THE COMPARISON OF SKELETAL & DENTAL CHANGES IN CONTROL AND TREATMENT GROUPS COMPARISON OF CONTROL & TREATMENT GROUP (SKELETAL MEASUREMENTS) Difference of Difference of Inter group Control Group Treatment Group Comparison Skeletal Angular Diff. Sd. W-test Diff. Sd. W-test Mann-Whiteny Measurements Test SNA 0.35 1.9 0.69 0.95 1.60 .08 0.30 SNB -0.15 2.06 0.51 -0.7 0.91 0.04* 0.57 ANB 0.5 1.17 0.23 0.65 0.39 0.01** 0.05* SN-Pog 0.5 2.19 0.85 -0.25 1.11 0.40 0.42 SN-Go-Gn -0.15 2.16 0.76 -0.05 0.016 0.94 0.85 FMA 0.8 3.22 0.38 0.65 1.94 0.31 0.67 Y-Axis 1.2 2.69 0.16 2.25 2.12 0.01** 0.36 Inner Angles 2.35 5.66 0.35 1.8 3.22 0.12 0.82 Gonial Ratio -1.48 4.31 0.37 0.63 2.4 0.61 0.21 Skeletal Linear Measurements Witt, S -0.05 2.03 0.86 1.05 1.96 0.14 0.32 N-Me -0.1 3.527 0.88 0.7 0.65 0.34 0.42 ANS-Me 0.5 1.84 0.40 1.9 3.63 0.09 0.15 Jaraback Ratio (S- 1.06 4.00 0.44 0.84 2.26 0.26 0.67 Go/N-Me) Facial Ratio 0.47 3.00 0.76 1.44 2.21 0.05* 0.40 ANS-Me/N-Me COMPARISON OF CONTROL & TREATMENT GROUP (DENTAL MEASUREMENTS) Difference of Difference of Inter group Control Group Treatment Group Comparison Angular Diff. Sd. W-test Diff. Sd. W-test Mann-Whiteny Measurements Test Ul-SN 0.15 5.38 0.35 4.45 5.77 0.05* 0.10 Ul-FH -0.1 3.23 0.94 2.65 5.07 0.10 0.18 Ul-Ll Angle 0.8 3.04 0.59 -22.8 6.37 0.44 0.10 Ul-NA 0.55 5.12 0.72 6.35 4.93 0.05* 0.04* Ll-NB -1.25 3.90 0.32 -4.45 3.39 0.01** 0.10 IMPA -1.15 4.34 0.33 -3.25 3.12 0.01** 0.34 Linear Measurements Ul-NA (mm) 0 1.26 0.59 1.1 2.89 0.28 0U1-NA Ll-NB (mm) -0.2 1.03 0.47 -1.45 0.86 0.01" 0.01" Ll-APog (mm) -0.05 0.92 0.39 -2.1 1.02 0.01** 0.001*** Overjet (mm) 0.2 0.91 0.91 3.65 1.51 0.01** 0.001*** Overbite -0.6 0.80 0.04* -0.65 1.49 0.28 0.93 P < 0.05* P < 0.01*** P < 0.001***

29 The I/Go-Gn angle, I/N-B angle and 1/N-B 8 Frankel, R, Frankel, C: A functional approach to the treatment of skeletal open bite. Am J Orthod. 84: 54-68, 1983. measurements decreased significantly indicating lingual tipping of the mandibular incisors. Although 9 Gianelly, AA, Brasnan, P, Martigonia, M, Bernstein, L; Man- dibular growth, condyle position and frankel appliance the vestibular arch of the appliance was not active, therapy. Angle Orthod. 53: 131-142, 1983. the anterior sagittal growth pattern of the mandible 10 McNamara, JA; Dentofacial adaptations in adult patients could have been prevented by the vestibular arch, following function regulator therapy. Am J Orthod. 85: 57. thus causing lingual tipping of lower incisors. 71, 1984. 11 Nielsen, IL; Facial growth during treatment with function Overbite decreased significantly (p>0.001) being regulator appliance. Am J Orthod. 85: 401-410, 1984. affected by the backward and downward rotation of the 12 Owen, AH; Clinical application of Frankel appliance. Angle mandible. Robertson28; Loh, Kerr19; Kerr and Ten Orthod. 53: 29-87, 1983. Have17; Kerr, Ten Have and McNamara 18 mentioned 13 Owen, AH; Morphologic changes in transverse dimension significant change in overbite using the FR-3. using the FR appliance. Am J Orthod. 83: 200-217, 1983. 14 Hsin Fu Chang, Two stage treatment of a severe skeletal Class-3, Overjet marked increased (p>0.001) caused by deep bite malocclusion. Am J Orthod: 481-486, 1997 downward and backward rotation of the mandible, 15 Angelo Conte; A new maxillary protractor. JCO, Aug (523- lingual tipping of the lower incisors and labial tipping of 530) 1997. the upper incisors. This has also been found by previous 16 Gerald R; Two piece corrector for class-3 skeletal and dental malocclusions. JCO, April (246-251) 1997. authors17,18,19,29,30. 17 Kerr, WJS, Have, T R T; A comparison of three appliance systems in the treatment of class-3 malocclusion. Eur J CONCLUSION Orthod. 10: 203-241, 1988. In concurrence with many authors we found 18 Kerr, WJS, Have, T R T, McNamara, JA; A comparison of skeletal and dental changes produced by function regulators (FR-2 and the following results from FR-3 therapy: FR-3). Eur J Orthod. 11: 235-42, 1989. 1— In this study the FR-3 appliance was not 19 Loh, MK, Kerr, WJS; The function regulator class-3: Effects and indications for use. Brit J Orthod.12: 153-157, 1985. found to have a significant effect in the sagittal 20 Ulgen, M, Firatli, S; The effects of Frankel's function regulator on forward growth of maxilla. class-3 malocclusion. Am J Orthod. 105(6): 561-567, 1994. 2— Redirection of mandibular growth in the vertical 21 Toshio Deguchi, Electromyographical investigations of chin cup therapy in class-3 malocclusion. Angle. Orthod: 68(5), direction caused an increase in the total face 419-424,1998. height and reduction in overbite. 22 Toshio Deguchi, Very early face mask therapy in class-3 children. Angle Orthod, 69 (4), 349-355,1999. 3— Changes in lower incisor inclination contributed a 23 Ikue Yoshida, Maxillary protraction and chincap appliance treat- favorable change in overjet. ment effects and long term changes in class-3 patients. Angle Orthos, 69 (6), 543-552,1999. REFERENCES 24 Bell, WH, Proffit, WR, Whife, RP: Surgical correction of dentofacial deformities. Pp. 844-1014, W. B. Saunders 1 Hunter, J; The natural history of human teeth. Part 2. A practical Co., Philadelphia, London, Toronto, 1980. treatise on the disease of teeth intended as supplement to the 25 Epker, BN, Fish, LC: Dentofacial deformities. Integrated orth- national history of those parts, London, J . Johnson, 1778. odontic and surgical correction. pp. 430-592, C. V. Mosby Co., 2 Broadbent, BH; A new X-ray technique and its application to St. Louis, Toronto. 1986. orthodontics. Angle Orthod. 1: 45-66, 1931. 26 Proffit, WR, White, RP Jr: Surgical orthodontic treatment. pp. 3 Wienberg, BW; Orthodontics: A Historical review. The C.V. 428-483, Mosby Year Book, St. Louis, Baltimore, Boston, Chi- Mosby Co. 1926. cago, London, 1991. 27 McNamara, JA, Huge, SA; The function regulator (FR-3) of 4 Partrick K Turley, Cephalometric effects of combined palatal Frankel. Am J Orthod. 8: 409-424, 1985. expansion in face mask therapy on Class-3 malocclusion. Angle Othod 68(3), 217-224, 1998. 28 McNamara, JA; An orthopedic approach to the treatment of class-3 malocclusion in growing children. J Clin Orthod. 5 Creekmore, TD, Radney, LJ; Frankel appliance therapy: Ortho- 21: 598-608,1987. pedic or Orthodontic. Am J Orthod. 83: 89-108, 1983 29 Kerr, MP, Welch, CD, Moore, RN, Tekieli, ME; Functional 6 Frankel, R: Maxillary retrusion in class-3 and treatment with regulator therapy for cleft palate patients. Am J Orthod. the function corrector 111. Trans. Eur Orthod. Soc. 249- 80: 508-524.1981. 59, 1970. 30 Kerr, WJS, Have, T R T; Changes in soft tissue profile during 7 Frankel, R: Decrowding during eruption under the screening treatment of class-3 malocclusion. Brit J Orthod. 14: 243-249, influence of vestibular shields. Am J Orthod. 65: 372-406,1974. 1987.