The Philippine Journal of Orthodontics Vol. 9 No. 1 September 2009

Transcription

1 The Philippine Journal of Orthodontics Vol. 9 No. 1 September 2009 A Bag of Tricks: Varying Timing of Extraction Facilitates Midline Correction: A Case Report Prof. A. B. Rabie, (Professor in Orthodontics, Faculty of Dentistry, The University of Hong Kong): M.S., Cert. Ortho., PhD, FDSRCS(Edin)(Hon), FHKAM (Dental Surgery), FCDSHK (Orthodontics). Dr. Fiona Y. C. Leung, (Part-time Clinical Lecturer, Orthodontics, Faculty of Dentistry, The University of Hong Kong): BDS; MOrth; Morth RCS (Edin): FHKAM (Dental Surgery); FCDSHK (Orthodontics). Dr. Ricky W. K. Wong, (Associate Professor in Orthodontics, Faculty of Dentistry, The University of Hong Kong: BDS, MOrth, PhD, FRACDS, MOrthRCS (Edin), FHKAM(Dental Surgery), FCDSHK (Orthodontics). Dr. Y. Q. Yang, (Associate Professor in Orthodontics, Faculty of Dentistry, The University of Hong Kong) Combined Orthognathic Surgery and Orthodontic Treatment for Class III Malocclusion: A Case Report Lourna Leah Velasco, MD, Bernard Tansipek, MD FPAPRAS, Anjana Karmacharya, BSD, MSD Cecile Tuaño, DMD, MSD Commonsense Formula to Achieve Harmony of Smile Manopatanakul S, Jearnsurajitwimol O, Faculty of Dentistry University of Bangkok, Thailand The Horse Shoe Appliance...A patient friendly effective method for early treatment of Class III Malocclusion Vaid Nikhikesh R., MDS, FWFO, FPFA, PG. Cert (Ling., Aligner Therapy) Raghunath N., MDS, Assoc. Professor, Dept. of Orthodontics Roy E. T., MDS, Professor, Dept. of Orthodontics Simha Ashok, MDS, M. Orth. RCS, Former Reader, Department of Orthodontics Treatment of a Class III Openbite Malocclusion: A Case Report Maria Janet Mapa-Pandan, DDM, Cert. in Orthodontics Treatment of a Malocclusion with Mandibular Lateral Deviation: A Case Report Rossana Lorenzo-Sanchez, DDM, Cert. in Orthodontics Treatment of a Class 1 Type III Malocclusion with Anterior Crossbite: A Case Report Crysoine R. Maquez, DDM, Cert. in Orthodontics Dr. Jose Manuel Rivera, APO President Dr. Emerlinda Sabater Galang, PBO Chair Board of Editors Dr. Martin V. Reyes Dr. Bobby Eustaquio The Philippine Journal of Orthodontics is the official journal of the Association of Philippine Orthodontics (APO) and the Philippine Board of Orthodontics (PBO) and is published for its members and subscribers by Dot-To-Dot Enterprise. It is dedicated to the continuing professional advancement of the orthodontists by publishing original articles related clinical orthodontic reports. Manuscripts, prepared in accordance with The Information for Authors should be submitted to the editors, or Dr. Martin Reyes c/o PBO Secretariat Tel/Fax Printed in the Philippines by DOT-TO-DOT ENTERPRISE, Fairview, Quezon City, M.M., Philippines

2 A Bag of Tricks: Varying Timing of Extraction Facilitates Midline Correction Prof. A. B. M. Rabie, (Professor in Orthodontics, Faculty of Dentistry, The University of Hong Kong): M.S., Cert. Ortho., PhD, FDSRCS(Edin)(Hon), FHKAM (Dental Surgery), FCDSHK (Orthodontics). Dr. Fiona Y. C. Leung, (Part-time Clinical Lecturer, Orthodontics, Faculty of Dentistry, The University of Hong Kong): BDS; MOrth; Morth RCS (Edin): FHKAM (Dental Surgery); FCDSHK (Orthodontics). Dr. Ricky W.K. Wong, (Associate Professor in Orthodontics, Faculty of Dentistry, The University of Hong Kong: BDS, MOrth, PhD, FRACDS, MOrthRCS (Edin), FHKAM(Dental Surgery), FCDSHK (Orthodontics). Dr. Y. Q. Yang, (Associate Professor in Orthodontics, Faculty of Dentistry, The University of Hong Kong) This case report presented an 18 years old Chinese female with chief complaint of shifted dental midlines and irregular teeth. The patient presented with molar Class II subdivision right relationship with both upper and lower midlines shifted to the right of facial midline. Varying timing of extraction of 14, 24, 34 and 45 was involved to facilitate the correction of the dental midlines. Introduction Materials and methods Occlusal asymmetries are commonly encountered problems This case report presented an 18 years old Chinese female, that pose both diagnostic and treatment difficulties in orthodontic CKY, with chief complaint of shifted dental midlines and irregular patients. Of all occlusal asymmetries, midline discrepancies are teeth. among the most complex and commonly seen problems, which are also the most obvious from the patients' perspective. Midline History discrepancies may be isolated, or may occur in concert with other occlusal asymmetries, particularly molar occlusion asymmetry, or CKY had pneumonia half a year ago and she had finished her the angle subdivision malocclusions. course of medications half year earlier. Otherwise medical history Patient with dentoalveolar asymmetries can present some of the was unremarkable. most biomechanically challenging situations to the orthodontists. One creative approach for managing dental asymmetries is to Diagnosis: extract a combination of teeth that will simplify intra-arch and inter-arch mechanics. Often this will also reduce the dependency on Extraoral : Straight profile 1 patient compliance for elastic wear. An appropriate biomechanical plan is important in order to Sagittally : Decreased skull base angle with post achieve the goals of the treatment plan to correct the midlines and normal basal relationship with the molar relationships. As a result of asymmetric extractions, the retrognathic mandible. Molar was Class II correction of maxillary and mandibular dental midline deviations subdivision right with incisor Class I. might be possible without canting of the occlusal plane. When applied to Class II subdivision malocclusion, treatment protocols Vertically : Increased overbite and increased curve of with asymmetric extractions do not introduce undesirable Spee. 2 3 dentoskeletal changes in the frontal plane. Nanda and Margolis recommended a few mechanics which can be used to be correct Transversely : Dental midline shift. midline and asymmetric molar problems. They are (1) bracket placement; (2) cantilevers; (3) asymmetric mechanics; (4) Dental arch : Asymmetrical arches with 13 ectopic and asymmetric extraction pattern; (5) varying the timing of extraction; displaced buccally. 42 instanding. Rotated (6) asymmetric intra-arch mechanics; (7) asymmetric palatal arch. and tipped teeth. This case report presented a few mechanics for correction of dental midlines and asymmetric molar relationship. Space condition : Crowding. Dentition : Generalized enamel opacity. Mild attritted 1

3 lower incisors. retracted. Lingual arch was removed later after 33 was retracted, maintaining a molar Class I relationship on the Soft tissues : Marginal gingivitis left. Treatment Plan: Anchorage : Anchorage demand was initial high to correct the midline. This was assisted by initial phase of Pre-treatment therapy : Oral hygiene instructions and dental transpalatal arch and lingual arch. Once the check up for caries and periodontal midline correction was consolidated with the status. Then patient would be scaled retraction of 23 and 33 and the alignment of 13, and cleaned. then the anchorage reinforcements were removed. Overall the anchorage demand was Appliances : Preadjusted edgewise fixed appliance with moderate..022 x.028 slot size and Roth's prescription for anterior incisors to add extra torque to the Proposed retention strategy : Upper and lower removable anterior incisors. Andrew's prescription was retainers 1 year full time followed by 1 year night used for the rest of the dentition. Transpalatal time. This was designed to allow the supracrestal arches and lower lingual arches with close gingival fibres of the rotated teeth to release the fitting around cingulum of the lower incisors stresses to enhance the stability of the results. were used. Prognosis for stability : CKY has post normal basal relationship Treatment plan: but the orthodontic treatment was mainly dental correction of her dental malalignment and 1) Bonding of the transpalatal arch and lingual arch and midline shift. Therefore the prognosis for her bonding of 23, 25, 33, 35 to allow the CKY to feel for the should be good as the position of the arches appliance before commiting to extraction. would not be expected to be altered, nor the 2) Extraction of 24 and 34 first intercanine and intermolar width. 3) Retraction of 23 and 33 4) Extraction of 14, 45 and removal of transpalatal arch and Treatment Progress/Mechanotherapy: lingual arch 5) Full fixed appliance treatment except 13 and allow 3 July 2000 Insertion of transpalatal arch and lingual arch as months for auto eruption down into the arch. anchorage control for dental midline correction. 6) Bond 13 and fixed appliance to align and harmonize the Left premolars and canines were bonded to allow arches. the patient to feel for the appliance before 7) Review of the developing 18, 28, 38, 48. Refer for committing to extraction as patient's mother was removal if impacted. very apprehensive about the treatment. Then extraction of 24, 34 followed by alignment Extraction: of 23, 25, 33, 35 with sectional.016 nickle titanium (NiTi) wires. Then.017 x sectional titanium moblydenum alloy (TMA) wires with closing loops were used to retract 23 and 33. Extraction of 14, 24 despite the midline shift to the right May 2001 Retraction of the canines took 7 months and then was due to localized crowding in quadrant one. Extraction of the canines were realigned with sectional 14 was used to allow 13 to drop down easily. Therefore x.025 NiTi archwires while waiting to was extracted first and 23 was retracted to aid the midline have the rest of the teeth bonded and 14 and 45 correction. Anchorage was demanding and transpalatal arch were extracted 1 month later. Then bonding of was only removed after the alignment of 13, just before upper and lower arches except 13 and alignment space closure to allow 26 to move forward and yet with.016 NiTi archwires. maintaining the position of 16 for as long as possible. Extraction of 34 and 45 was used to correct the lower November was bonded 4 months after extraction of midline and lingual arch was used initially to hold 36 and 14 to allow spontaneous alignment. prevent retroclination of the lower incisors while 33 was Alignment of 13 and derotation with.016 2

4 NiTi archwire. Removal of the transpalatal Discussion of the case arch and lingual arch 6 weeks later. CKY had satisfactory extraoral features, despite cephalometric Jan 2002 Upper and lower teeth were aligned and analysis showed that she had post-normal basal relationship and levelled with progressively stiffer stainless decreased lower facial height. Therefore the aim was just to align steel archwire to.017 x.025 (SS) stainless the teeth and correct the dental midlines and the mild increase in steel archwire. overbite. She was partially banded and bonded for her to try the fixed appliance before commiting to extraction as her mother was May 2002 Retraction of 13 into Class I relationship with worried that the appliance could affect eating and health. Our NiTi closed coil springs and anchorage was treatment planned to partially bond the left side first could also ease reinforced with Class II elastics. 36 was her into adapting to the fixed appliance. allowed to slip forward into Class I. 22 was As to the extraction choice, although CKY's incisors were distalized with NiTi closed coil spring to upright but there was moderate crowding in the maxillary arch and facilitate maxillary midline correction and therefore extraction of 14, 24 was decided. There was an option of anchorage facilitated by Class II elastics extraction of 34, 45 or 35, 45 as there was not a lot of crowding in the mandibular arch. Although the second extraction option was September 2002 Maxillary.017 x.025 SS archwire with symmetrical and was easier to maintain arch asymmetry, but closing loops and step up of anterior labial extraction of 34, 45 could allow retraction of 33 with 23 to correct segment. Mandibular.017 x.025 SS midline and yet maintaining the molar relationship on the left archwire with step down of the lower anterior (which was initially Class I). Extraction of 45 could allow the lower segments to clear the overbite for upper right molar to slip forward into a Class I relationship with 16. There incisors retraction. Class II elastics were used was more anchorage demand in the maxillary arch thus transpalatal to slip the lower posterior segment forward. arch was used to hold the molars until 23 was retracted and 13 was NiTi closed coil springs were later used in levelled with the maxillary arch. Lingual arch was used to maintain mandibular arch to close minute spaces. the molar relationship on the left and the anterior-posterior position of the lower incisors until 33 was retracted into a Class I March 2003 Finishing models and radiographs were taken relationship with 23. to assess the results. The lower labial segment Removable retainers were chosen for CKY because the incisors was upright and overbite and overjet was were generally not severely rotated and removable retainers could slightly increased and molar relationship, allow the patients to maintain her oral hygiene more easily. Longer although Class I, could be improved. regime was used to improve stability of rotated teeth. As the Therefore, with agreement from the patient, anterior posterior position of the anterior teeth and the intercanine 32 to 42 were proclined first with.016 SS, and intermolar widths would not be altered, therefore stability then stepped down with.017 x.025 TMA. should be promising. When space was developing behind 33 and Treatment period for CKY was long. Initial trematnet was slow 43, the lower anterior segment was tied with for the patient to adapt to the appliance due to the parent's concern. ligature for anchorage while 34 and 44 were Space closure stage was anticipated to be longer than normal mesialized with powerchain. Class II elastics because 23 and 33 were retracted first before alignment of other was used to slip the lower posterior segment teeth and retraction of 22 alone was needed to facilitate midline forward. correcton. Another major factor was that more than 9 months were Patient was referred for removal of 18, 28, 38, used to correct the very slight increased overjet and overbite. 48 as they were impacted. Although the increase in overjet and overbite and tendency for Class II molar relationship was mild, but after the discussion, the Feb 2004 Finishing and detailing with.016 SS patient had agreed to spend more time to correct it. archwires with step down 15 and offset 13, Overall, the orthodontic treatment had fulfilled the treatment 23, 35, 44, inset 12,22. Banding of second objectives set out, which was to correct the dental malocclusions molars and aligned. and maintain the facial profile. Although the post treatment angulation of the upper incisors could be improved. More palatal Jul 2004 Fixed appliance debonded after alignment of root torque could have been inserted. the second molars. Removable upper and Molars were Class I although the 13 position could be lower retainers were inserted to allow for improved. The tooth size of this patient was asymmetrical settling and maintenance of treatment results. contralaterally and this could explain the slight difference in intercuspation between the two sides. The position of 46 could be 3

5 more buccally placed to improve the buccal overjet between the 16 and 46. Then the symmetry of the arch form could also be improved. Alignment of 13 with high gingival margins was satisfactory as time was allowed for it to spontaneously erupt into the level of the other maxillary dentition and thus the gingival margin followed nicely. Active treatment time for this case should have been improved. An extra 9 months was spent to correct minor increase in overjet and overbite, which was originally clinically acceptable. The cost was weighted against the benefit. As the CKY's root showed no abnormal root resorption upon radiograph examination and that patient's oral hygiene was satisfactory, therefore it was agreed with the patient that an extra few months would be used to improve the overjet and overbite and the intercuspation of the posterior segment. When looking back, the lower incisor space closure should have been done on a thicker stainless steel archwire to burn more anchorage form the back and the lower incisors could have been torqued to further resist posterior movement of the lower anterior segment during space closure. The use of Class II elastics on.017 x.025 SS archwires was not enough to prevent the anterior segment moving back during space closure. Overall, the treatment objectives were fulfilled and the prognosis for dental stability was satisfactory as the incisor position, the intercanine and intermolar width were maintained. Conclusions Pre-Treatment Panoramic Radiograph Mid-Treatment Photographs: 23 and 33 were retracted with sectional.017 x.025 TMA closing loops to prepare for dental midline correction Asymmetric extraction pattern and varying the timing of extraction are effective mechanics for correction of dentoalveolar asymmetries presenting with Class II subdivision molar relationship and midline deviation. Pre-Treatment Photographs Retraction of 22 with niti closed coil spring to facilitate maxillary midline correction. NiTi closed coil spring, delivering light force to distalize 12. The lrge posterior anchorage segment was reinforced with ligature tie. Space closure with.17 x.025 stainless steel closing loops. Maxillary midline was shifted 1mm to right and space was available distal to 21 to correct the midline. Posterior occlusion was supraclass I. 12 to 22 were stepped up and 33 to 43 were stepped down to open the bite more and counter the extrusive effects of the closing loops. 4

6 Post-Treatment Photographs Cephalometric Assessment (Chinese Normals) Post-Treatment Panoramic Radiograph REFERENCES Rebellato J. Asymmetric extractions used in the treatment of patients with asymmetries. Semin Orthod 1998;4(3): Turpin DL. Correcting the Class II subdivision malocclusion. Am J Orthod Dentofacial Orthop 2005;128(5): Nanda R, Margolis MJ. Treatment strategies for midline discrepancies. Semin Orthod 1996;2(2): Cephalometric Superimposition Overall superimposition: registered on Sella-Nasion line at Sella. Maxillary superimposition: the mandible was superimposed on the mandibular plane Mandibular superimposition: the maxilla was superimposed on PNS to ANS. 5

7 Combined Orthognathic Surgery and Orthodontic Treatment for Class III Malocclusion : A Case Report Lourna Leah Velasco, MD Bernard Tansipek, MD, FPAPRAS Anjana Karmacharya, BDS, MSD Cecile Tuaño, DMD, MSD A twenty-one year old male, who initially consulted at the Department of Orthodontics, College of Dentistry, University of the Philippines, Manila in May 2003 complaining of a large lower jaw, long face, open bite and reverse bite. He was diagnosed to have severe skeletal and dental class III malocclusion. On examination, there was a negative overjet of 15 mm and anterior open bite of 4 mm. There was also canting of the occlusion and asymmetry of the face with deviation of the chin to the right. Orthodontic treatment along with double jaw surgery and genioplasty was performed for correction of his malocclusion. Introduction The etiology of mandibular prognathism is believed to be 6 genetic. A wide range of environmental factors have been The word orthognathic is derived from 2 Greek words, suggested as contributing factors for the development of class-iii 7 (orthos) meaning to straighten and (gnathos) meaning jaw. The malocclusion. These factors include endocrine disturbances, 8 history of orthognathic surgery goes back as early as 1846 when occlusal discrepancies, and parafunctional or acquired habits. Hullihan performed an anterior mandibular subapical osteotomy Treatment options for class III malocclusion include 1 and setback. However, the term has since then evolved. orthodontic tooth movement combined with growth modification, Orthognathic surgery is now defined as the surgical manipulation camouflage by extraction of lower bicuspids and retraction of the of the facial skeleton with the objective of restoring a proper lower anterior teeth, and orthodontics combined with orthognathic anatomic and functional relationship in patients with congenital, surgery. The limit of each these options is best illustrated by the 2 developmental or acquired dentofacial skeletal deformities. envelope of discrepancy. Severe problems would obviously Defining a straight jaw usually requires a set of values based on a require a multi-disciplinary team approach. specified population norm. Orthognathic surgery, aside from restoring orthognathic form and conforming to a set of supposedly Diagnosis normal values, also aims to achieve facial esthetics of the individual 1 patient. A 21 year old male patient presented at the Graduate Program in The frequency of Class III malocclusion varies with the Orthodontics, College of Dentistry, University of Philippines, population studied. In the American population, the prevalence of Manila with the following complaints: a large jaw, a long face, moderate to severe Class III malocclusion is higher in Blacks (1.9 open bite and reverse bite. He had a severe Class III malocclusion %) and Hispanics (1.6%) than in whites (0.8%) across all age with a negative overjet of 15 mm complicated by an anterior open 2 groups. In Asia, Class III problems are more prevalent in Orientals bite of 4 mm. His medical history was normal. Both the lower first 3 between 3 to 5% in Japan and nearly 2 % in China. molars were extracted due to caries. He had good oral hygiene. Philippine data however, is sadly lacking. Review of local The patient (Figure 1) exhibited a concave profile. He had a literature using the Herdin Database, a compilation of 23,000 local dolichocephalic face with mild asymmetry and deviation of the journals from different subspecialties from show very chin to the right. The maxilla was retrognathic and the mandible little published data on the prevalence rates, as well as orthognathic was prognathic. He had a large forehead and the mento-labial surgery in the Philippines. A case report on a patient with class III sulcus was absent. There was lower lip strain at rest. 4 malocclusion was presented in 1994, although the treatment plan Molar relations (Figure 2) could not be established due to the made use of expansion plates. Another local study on a series of 15 extraction of tooth numbers 36 and 46. The canine relationship on patients who underwent intraoral vertical ramus osteotomy for both sides was class III. There was an overjet of 15 mm, an openbite 5 correction of mandibular prognathism, discussed how post- of 4 mm and a posterior crossbite. The lower midline was deviated operative condylar sagging may be treated non-surgically with to the left by 2 mm. The lower incisors were severely retroclined. post-operative elastic traction. No journals were found locally on There was mild rotation of tooth numbers 14, 24, 34, 35, 44, 45. The sagittal split osteotomy, or two jaw surgery for class III malocclusion. 6

8 upper arch appeared slightly small in size compared to the large lower jaw. Both upper and lower arches were V" shaped and tapered from the posterior to the anterior teeth. The panoramic radiograph (Figure 3) revealed impaction of tooth numbers 18 and 28 with 28 in the inverted position. Tooth Figure 1. Pre-Treatment facial photographs Figure 4. Pre-Treatment Lateral Cephalometric Radiograph and Tracing Figure 2. Pre-Treatment dental casts. (Table 1) These showed a slightly retrusive maxilla and a severely protrusive mandible. The vertical skeletal cephalometric measurements likewise reflected values which were deviated from the norm. The UFH/LFH was 58.62%, UFH/TFH was 36.96% and the LFH/TFH was 63.04%. These illustrate the disproportionate dimensions of the upper and lower face. The lower face was relatively longer than the upper face. The mandibular plane angle was high (MP:SN=37 ). The dental cephalometric values also revealed retroclined lower incisors (L1:MP=58 ) and proclined upper incisors (30 ). Both upper and lower incisors were positioned slightly forward compared to their bony bases (U1:NA=9 mm, L1:NB=10 mm). The soft tissue analyses corroborated the findings of the skeletal analyses. The upper lip was retrusive while the lower lip was protrusive. The upper and lower faces were not proportional. Although the patient's Z angle was normal (90 ), this did not intersect the anterior aspect of the nares. Treatment Objectives Figure 3. Pre-Treatment panoramic radiograph. The treatment objectives were: (1) to improve the profile, (2) to correct the open bite and achieve correct overjet and overbite, (3) to achieve class I canine relation, (4) to place the incisors in correct axial inclination, (5) to correct the rotation of teeth (6) to correct of the lower midline, (7) to achieve good interdigitation, and, (8) reduce the excessive lower anterior face height. Treatment Plan numbers 37, 38, 47 and 48 were mesially tipped into the extraction space of the lower first molars. Normal bony trabeculation and density were seen. The body of the mandible in the molar areas was thin. The cephalometric radiograph and tracing are shown in Figure 4. The ANB angle was -12, SNA was 80 and the SNB was Pre-surgical orthodontic treatment: Levelling and alignment of both the arches. Decompensation. Stabilization of the arches with a rigid wire. * Extraction of the lower 3rd molars to allow the large mandibular setback. 2. Surgical intervention: Le Fort I surgery with maxillary advancement, correction of the canting and rotation of the maxilla upward posteriorly. Bilateral sagittal split osteotomy with mandibular setback and genioplasty. 7

9 3. Post surgical orthodontics: predicted outcome (for the maxilla and mandible) were hand traced Final finishing and detailing. on a single sheet of acetate. The same cephalometric analysis Retention with Hawley's appliance. performed on the pretreatment radiograph was also done on the tracing of the simulated outcome. These were then compared with 4. Other dental treatment the norms to check if the outcome was favorable. Replacement of missing lower first molars with a fixed The following surgical movement was planned: 7 mm of or removable prosthesis maxillary advancement, 1.5 mm canting correction of the left side of the maxilla, rotation of the maxilla at PNS by 3mm upward and PRESURGICAL ORTHODONTIC TREATMENT 11 mm of mandibular setback. The amount of genioplasty was determined during the surgery. All teeth were bonded except for the molars, which were banded. Standard edgewise brackets (.022 slot) were used. The upper teeth were angled backward while the lower teeth were angled forward with the progressive use of larger diameter wires. This increased the negative overjet but facilitated the maximum amount of mandibular setback during the surgery. The length of time the patient was on braces prior to surgery was 5 years because the patient was initially undecided about having surgery and because of financial considerations. Cephalometric Analysis and Surgical Prediction A combination of different cephalometric analyses was used as guidelines in predicting the amount of horizontal and vertical 9 surgical movement. The amount of surgical movement was predicted manually by using separate acetate tracings of the maxilla Figure 5. Presurgical and mandible superimposed on the presurgical cephalometric Posteroanterior Cephalometric Radiograph tracing of the patient. The horizontal position of the maxilla was determined using Model Surgery and Splint Fabrication 10 McNamara's nasion perpendicular to point A. The horizontal position of the mandible was determined using nasion Face bow recordings were taken which were then transferred to perpendicular to pogonion. Ideally the measurements point A and a Hanau articulator (Teledyne Dental, Hanau Division Buffalo, pogonion should approximate nasion perpendicular. After careful NY). The casts were mounted accordingly. Model surgery was analysis of the patient's measurements, 7 mm of maxillary performed based on the values from the paper surgery. Two set of advancement and 11 mm of mandibular setback was planned. The splints were fabricated. probable posttreatment soft tissue outline was established by using The upper cast was removed from the articulator and the amount 11 guidelines for the ratio for soft tissue to hard tissue changes. of maxillary movement (7 mm of maxillary advancement, 1.5 mm The vertical position and proportion of the jaws were canting correction of the left side and rotation of the maxilla at PNS 12 established using the analysis of Delaire, et. al. Ideally the upper by 3 mm upward) were simulated on the upper cast by selectively facial height (nasion to ANS) should be 45% of the total facial removing the appropriate amount of stone from the cast. The upper height. The lower facial height (ANS to menton) should be 55% of cast was then replaced on the articulator The first splint was the total facial height. The patient had a UFH/TFH ratio of 38.13% fabricated with the upper and lower teeth in occlusion. Since and a LFH/TFH of 61.87%, prior to surgery. This means that the surgery to the maxilla was done prior to the mandible, the first splint lower portion of the anterior part of the face was relatively longer with the correction on the maxilla only, was used for checking the than the upper anterior part of the face. In order to make these amount of maxillary advancement in relation to the mandible. After values more ideal, 3 mm impaction of the posterior part of the the first splint was fabricated, the lower cast was then removed maxilla was planned. from the articulator and 11 mm of stone was removed from the The posteroanterior cephalometric tracing (Figure 5) revealed posterior portion of the cast to simulate a similar amount of canting of the left side of the maxilla with the lower midline mandibular setback. The lower cast was replaced on the articulator deviated to the right. Impaction of the left side of the maxilla by 1.5 and a second splint was made with the upper and lower teeth in mm was planned in order to correct these problems. occlusion. Holes were placed on the occlusal portions of both Once the amount of surgical movement was finalized, splints to facilitate fixation during the surgery. The splints were important landmarks in the lateral cephalometric tracing for the trimmed, polished and disinfected. 8

10 SURGICAL PHASE The patient was put under general anesthesia via naso-tracheal intubation. Surgical prep was accomplished with betadine antisepsis solution. Lidocaine was infiltrated at the mandible near the area of the coronoid. The mandible was exposed first using a lower gingivobuccal incision after infiltration with 1:100,000 epinephrine with 1% lidocaine solution. The incisions on both sides of the buccal sulcus were carried down to the periosteum, maintaining a cuff of muscle attached to the gingival for adequate anchoring and closure. A subperiosteal plane dissection was done to free the mandible from the surrounding muscle The dissection was carried all the way to the angle of the mandible. On the medial or lingual side, the subperiosteal dissection was also done until the level of the lingula, where the inferior alveolar nerve enters the mandible. A cutting burr was used to mark the mandible. A reciprocating saw was used to create the sagittal split, protecting the entrance of the inferior alveolar nerve. Careful chisel placements were done to split the mandible down to the inferior border. This procedure was done on both sides of the mandible. The upper sulcus was infiltrated with 1:100,000 epinephrine with 1% lidocaine solution. An intra-oral incision was done to expose the maxilla. Careful subperiosteal dissection was done until the maxilla was exposed almost up to the level of the infraorbital nerve. A Le Fort 1osteotomy was then done with careful downfracturing of the Le Fort 1 segment. (Figure 6). Once both maxilla and mandible segments were free, acrylic splints with intermaxillary wiring were used to obtain an acceptable occlusion. (Figure 7) The maxilla was advanced 7 mm and was rotated 3 mm upward posteriorly. The the anterior portion of the maxilla or ANS was kept stable). The mandible was set back 11mm. The occlusal plane was also levelled. This was fixed with titanium miniplates (Figure 8) The incisions were closed layer by layer. Genioplasty was then performed by making a transverse osteotomy (Figure 9). One centimeter width of bone was removed, and the remaining mentum fixed using titanium plates and screws. Immediate post-operative profile showed improvement of the aesthetic plane and nasolabial angle, as well as a more prominent labiomental sulcus. (Figure 10). There was note of minimal swelling 4 days post operatively. (Figure 11) The patient was discharged with elastics and maintained on soft diet. Post operative panorex show plates and screws in place (Figure 12). Occlusion was established with an overjet of 2mm and overbite of 2 mm. Good canine class I relationship was achieved with proper interdigitation. Figure 6. Le Fort 1 Osteotomy Figure 7: Sagittal split osteotomy shown after intermaxillary fixation Figure 8. Fixation with titanium plates. Figure 9. Genioplasty. POST SURGICAL RESULTS The postsurgical treatment intraoral photographs (Figure 14) show a Class I canine relationship and normal overjet and overbite. The postsurgical treatment facial photographs (Figure 13) reveal The upper and lower midlines now coincide. an improvement in the balance and harmony of the facial proportions. The postsurgical treatment cephalometric radiograph and The patient can now close his mouth without any lip strain. tracing (Figure 15) show the results achieved after presurgical 9

11 orthodontics and surgery. Table 1 shows a comparison of the The superimposed lateral cephalometric tracings (Figure 16) pretreatment, presurgical and postsurgical cephalometric illustrate the amount of maxillary advancement, mandibular measurements. The SNA angle increased from 80 to 85 while the setback, mandibular autorotation and facial profile improvement. SNB angle decreased from 92 to 86. Point A and Pogonion are The superimposed posteroanterior cephlometric tracings now nearer to nasion perpendicular (1.5 mm and 6 mm (Figure 17) show the amount of canting correction by differential respectively). The clockwise autorotation of the mandible due to surgical impaction of the left side by 1.5 mm. the surgical impaction of the maxilla at PNS may have also contributed to the correction of the skeletal discrepancy. The vertical skeletal proportions of the face improved significantly after the surgery and now closely approximates the norm. The proportion of the upper facial height and the lower facial height increased from 58.62% to 80%. The proportion of the posterior facial height to the anterior facial height increased from 57.97% to 65.62%. Down's mandibular plane angle decreased from 35 to 27.5 while Steiner's mandibular plane angle decreased from 37 to 25. Although the mandible may have autorotated clockwise due to the surgical impaction of the maxilla by 3 mm, this did not Figure 13. Postsurgical Treatment significantly increase the mandibular plane angle. Facial Photographs (12 months post-operative) The soft tissue cephalometric values (Table 2) showed marked improvement and reflected the amount of surgical skeletal movement. The position of the upper and lower lip now approximates E plane (E plane: LS and E plane LI = 0). The vertical soft tissue proportion of the upper and lower face is now near the ideal (0.92:1). Figure 10: Immediate post-operative profile. Figure 14. Postsurgical Treatment Intraoral Photographs (12 months post-operative). Figure 11. Four day post-operative facial photographs. Figure 12. Post surgical panoramic radiograph. Figure 15. Postsurgical Lateral Cephalometric Radiograph and Tracing. 10

12 Table 1. Anteroposterior and Vertical Skeletal Lateral Cephalometric Analysis. Type of Analysis Pretreatment Presurgical Postsurgical Normal Skeletal (Anteroposterior) SNA Steiner * SNB Steiner ANB Steiner Nasion : Point A McNamara (1.1) (mm) Pogonion: Nasion McNamara (-.3) (mm) Chin Projection Steiner Skeletal (Vertical) UFH (N:ANS to Delaire None FM) (mm) LFH (ANS:Me to Delaire None FM) (mm) UFH/LFH (%) Delaire 58.62% 61.63% 80% (81%) TFH (N-Me to FM) Delaire None (mm) UFH/TFH (%) Delaire 36.96% 38.13% 37.5% (45%) LFH/TFH (%) Delaire 63.04% 61.87% 46.88% (55%) N:Me (Anterior facial Bjork and Jarabak (107) height) (mm) S:Go (Posterior Bjork and Jarabak (72) facial height)(mm) S:Go / N:Me (%) Bjork and Jarabak 57.97% 58.63% 65.62% (68%) MP:SN Steiner MP:FH Down *Values not in parentheses are Filipino norms. Figure 16. Pretreatment and Postsurgical Lateral Cephalometric Tracings. Figure 17. Postsurgical Posteroanterior Radiograph. Orthognathic surgery requires a multispecialty team composed of the craniofacial surgeon, the dentist and orthodontist, and treatment may not be completed months or even years after the initial consult. The patient's treatment plan is composed of three stages: the pre-surgical orthodontic phase, the surgery itself, and the post surgical orthodontics. In the presurgical orthodontic phase, a complete history and physical examination of the patient is secured. Systemic diseases and symptoms of temporomandibular joint problems are screened 13 carefully, as these may affect the treatment planning. Cephalometric studies based on standardized radiographs and panorex views are done to determine the degree of compensation. Oral hygiene and periodontal health is maintained. Alignment and decompensation of the teeth are attained with orthodontics. Once correction of the decompensation is achieved, sometimes extending to more than 1 year as in our patient, facial evaluation is then done. The face is divided into thirds: trichion to glabella, glabella to subnasale and subnasale to menton. Each of these DISCUSSION should be approximately equal. Incisor show during lip repose and smiling are also recorded. The maxillary and mandibular dental Dentofacial anomalies may be a result of differential midlines are also assessed to determine if they are congruent with development of the upper and lower facial skeleton. They may be each other and any asymmetry carefully recorded. The relative congenital, or secondary to facial clefts or synostosis. They may position and size of the maxilla and mandible in relation to each also be acquired or secondary to trauma or tumor. Aside from other and to the cranial base is evaluated using radiographs. achieving normal occlusion, that is, class 1 occlusion, surgery also The tracings of the cephalometric studies are analyzed and aims to restore facial esthetics to the patient. Orthodontic dental casts are made. From these casts, the amount of setback treatment, while able to address mild cases of malocclusion, may needed for the desired occlusion is computed. Much of the take years of treatment for severe cases of malocclusion, and even technical planning for these types of surgery depends on the then, may not be able to adequately meet the treatment objectives. accuracy of the model surgery. Furthermore, orthodontic treatment by itself, will not address the Several methods of simulating treatment outcomes and surgical facial disproportions usually seen in these patient. As such, some treatment planning have been reported, such as various computer deformities cannot be corrected with purely orthodontic or purely 14,15,16,17 18 software and manual cephalometric surgical prediction. surgical treatment, but must be approached by a combination of However, due to the unavailability of software, the cephalometric both treatment modalities to be able to fulfill fully both objectives. analyses for this patient were done by hand, tracing the 11

13 radiographs. Separate acetate tracings of the maxilla and mandible differential arch movement, or rotation of the maxilla-mandibular were then overlaid on the original tracing to simulate the predicted 20 complex enable the team to shorten drastically the preoperative movement. Manual tracing and surgical treatment planning are orthodontic treatment. This proves to be advantageous for the 1 economical and are not less accurate than computer software. patient, as the orthodontic braces provide much discomfort and A combination of different cephalometric analyses were used in difficulty in the pre-operative period. Another advantage to this order to plan the orthodontic and surgical treatment of this patient approach is that facial aesthetics, which may be the primary reason because no single analysis can comprehensively show the for the consultation rather than the malocclusion, is corrected much horizontal, vertical and angular measurements of the skeletal and 21 earlier in the treatment. The post-operative orthodontic treatment dental components of the face. The use of different analyses also may extend to another 6 to 12 months after the surgery. May extend allowed the clinicians to ascertain the diagnosis and treatment to another 6 to 12 months after the surgery. outcome of this case. Post-operatively, some degree of relapse is expected. Several 18 According to the envelope of discrepancy, the maximum studies report a great variation of the degree of horizontal relapse amount of change that could be produced by orthodontic tooth from 2.3% to 91.3%. Vertical relapse is however, minimal in most movement alone is 5 mm, if the lower teeth are to be moved back of these studies. A study by de Villa et al, published in 2005, showed and 7 mm, if the upper teeth are to be moved forward. These clearly the long-term results of BSSO in 20 patients who underwent show that orthodontic movement alone cannot resolve the patient's cephalometric radiographs at 6, 12 and 28 months. They concluded problems. that there was no correlation between the magnitude of setback and One-jaw or two-jaw surgery may be planned keeping in mind the amount of horizontal relapse. However there was significant the goals of the treatment plan. Various types of osteotomies may correlation between the amount of downward displacement and the be used to correct midface and mandibular deformities. Among amount of vertical relapse. These changes are most prominent at 1 those used for the midface are the three types of Le Fort osteotomy 22 year post-operatively. The movement of the chin is anteriorly and and maxillary segmental osteotomies. For correction of superiorly, and may be due to bone remodeling and resorption. mandibular deformities, the following are commonly used: sagittal 23 This conclusion was supported by another study by Huang split osetotomy of the ramus, vertical ramal osteotomy, inverted L published in The intraosseous or bone remodeling changes and C osteotomies, mandibular body segmental osteotomies and that occur in the mandible, is more often seen in the condylar and 19 mandibular symphysis osteotomies. Horizontal osteotomy of the gonial areas, and may continue for a period of time. The chin itself, symphysis is usually used for correction of sagittal chin remains stable. deficiencies. At present the patient is still undergoing postsurgical A comparison of the cephalometric values reveal an orthodontics to close the spaces, improve the inclination of the improvement in most of the variables(tables 1 and 2). The Z angle lower incisors and detail the occlusion. Once the appliances are measurement did not change. After surgery, however, this line now removed, Hawley retainers will be installed and a prosthesis will be intersects the anterior aspect of the nares, indicating that the soft made to replace the missing lower first molars. tissue pogonion moved posteriorly. The proportion of the upper facial height to the total facial height hardly changed. Although a vertical reduction genioplasty was done to decrease the height of the lower face, the 3 mm posterior impaction of the maxilla may References: have caused the mandible to rotate clockwise and minimized the positive effects on the facial proportion of the upper face. However 1 Weinzweig, Jeffrey MD. (1999). Plastic Surgery Secrets. there was an overall improvement in the proportion and harmony of Philadelphia, PA: Hanley and Belfus, Inc.. the face with the UFH/TFH, LFH/TFH, S:Go/N:Me (Table 1) approximating the normal values. These caused an improvement 2 Proffitt WR, Fields HW, Sarver DM. (2007). Contemporary in the soft tissue proportion G-Sn/Sn-Me (Table 2) and a th Orthodontics. (4 ed.). St. Louis, Missouri: Mosby Year Book. corresponding enhancement in the patient's appearance. The position of skeletal pogonion improved from 13 mm to 6 3 El-Mangoury NH, Mostafa YA. Epidemiologic Panorama of mm. The postsurgical value is about 5 mm short of the ideal because Malocclusion. Angle Orthodontist. 1990;60: of limitations: the maximum amount of mandibular setback and variable soft tissue response after surgery. 4 Bjornaas II. Bilateral orthognathic surgery in a class III Some centers abroad shorten the preoperative orthodontic malocclusion: a case report. DDM J 1994 Marc 7(1): treatment to 2 to 3 weeks using the Surgery-First Approach to Orthognathic Surgery. The preoperative orthodontic phase 5 Rotskoff KS, Herbosa EG, Nickels B. Correction of condylar includes bonding and banding of orthodontic brackets, dental displacement following intraoral vertical ramus osteotomy. J impression, treatment planning and model surgery. Modifications Phillip Dent Assoc Dec-Feb 44 (3): 37. in the surgical technique, such as multiple segmental osteotomy, 12

14 6 Watanabe M, Suda N, Ohyama K. Mandibular Prognathism in 16 Jones RM, Khambay BS, Mchugh S, Ayoub AF. The Validity of Japanese Families ascertained through Orthognathically Treated a Computer-Assisted Simulation System for Orthognathic Surgery Patients. American Journal of Orthodontics and Dentofacial (CASSOS) for Planning the Surgical Correction of Class Orthopedics. 2005;128(4): IIISkeletal Deformities : Single-Jaw versus Bimaxillary Surgery. International Journal of Oral And Maxillofacial Surgery. 7 Jena AK, Duggal R, Mathur VP, Parkash H. Class - III 2007;36;10: malocclusion: Genetics or Environment? A Twins Study. Journal of the Indian Society of Pedodontics and Preventive Dentistry. 17 Schultes G, Gaggl A, Kärcher H. Accuracy of Cephalometric and 2005 Mar;23(1): Video Imaging Program Dentofacial Planner Plus in Orthognathic Surgical Planning. Computer Aided Surgery. 8 Pinho TM, Torrent JM, Pinto JG. Orthodontic Camouflage in the 1998;3: Case of a Skeletal Class III Malocclusion. World Journal of Orthodontics. 2004;5: Proffitt, WR with Fields, HW. (1993). Contemporary nd Orthodontics. (2 ed.). St. Louis, Missouri: Mosby Year Book. 9 Taiwan Cleft Palate-Craniofacial Association and Chang Gung Craniofacial Center. (2007). The International Workshop on Surgical- 19 Patel, Pravin K MD, Gassman, Andrew MD. Craniofacial, Orthodontic Approach to Dentofacial Deformity. Taoyuan, Taiwan. Orthognathic Surgery. Retrieved December 2, 2008 from 10 McNamara, JA Jr. A Method of Cephalometric Evaluation. American Journal of Orthodontics and Dentofacial Orthopedics. 20 Shing Huang, Daniel C. (2007) Rationale and Indications of 1984 Dec; Surgery-First Approach: The Orthodontist's Point of View in The International Workshop on Surgical-Orthodontic Approach to 11 Ko, EWC. Case Demonstration: Facial Measurement, Model Dentofacial Deformity. Taoyuan, Taiwan. Measurement and Mounting. (2007). The International Workshop on Surgical-Orthodontic Approach to Dentofacial Deformity. 21 Chen, Yu-Rey. (2007) Origin and Development of Surgery- Taipei, Taiwan. First Approach: The Surgeon's Point of View in The International Workshop on Surgical-Orthodontic Approach to Dentofacial 12 Delaire J, Schendel SA, Tulasne, JF. An Architectural and Deformity. Taoyuan, Taiwan. Structural Craniofacial Analysis: A New Lateral Cephalometric Analysis. Oral Surgery. 1981;52: de Villa, Glenda H DMD, Huang, Chiung-Shing DDS PhD, Chen, Philip KT MD, Chen, Yu-Rey MD. Bilateral Sagittal Split 13 Thorne, Charles H, et al. (2007) Grabb & Smith's Plastic Surgery Osteotomy for Correction of Mandibular Prognathism: Long Term th ( 6 ed.. Philadelphia, PA: Lippincott Williams & Wilkins. Results. Journal of Oral and Maxillofacial Surgery. 2005;63: Power G, Breckon J, Sherriff M, Mcdonald F. Dolphin Imaging Software: An Analysis of the Accuracy of Cephalometric 23 Huang, Chiung-Shing DDS, Phd, de Villa, Glenda DMD, Liou, Digitization and Orthognathic Prediction. International Journal of Eric DDS, MS, Chen, Yu-Rey MD. Mandibular Remodeling after Oral and Maxillofacial Surgery. 2005;34(6): Bilateral Sagittal Split Osteotomy for Prognathism of the Mandible. Journal of Oral and Maxillofacial Surgery. 15 Marathiotou,II and Papadopoulos, MA. Assessment of 2006;64: Cephalometric Analyses used for Craniofacial Complex Evaluation: Part I - Sagittal Maxillary Position. Hellenic Orthodontic Review. 2005;8(1):

15 Commonsense Formula to Achieve Harmony of Smile Manopatanakul S, Jearnsurajitwimol O, Faculty of Dentistry, Mahidol University, Bangkok, Thailand While the aim of orthodontic treatment is to create an ideal occlusion, patients seek treatment mainly for aesthetic reasons. To balance these, aesthetic efforts in the creation of the harmony of smile should be reinforced. Although, many factors are listed for perfect pleasing smile, it is the aim of this article to define the commonsense formula as a list of factors with strong impact on harmony of smile. Case examples with simple minor tooth movement and short treatment time, however, with distinguished results are showed. Introduction Orthodontist tends to emphasize more on the occlusal relationship rather than the harmony of smile. The goal of orthodontic treatment always stresses on excellent result on plaster models. Moreover, the criterion of the American Board of Orthodontics for treatment success may not guarantee the harmony of smile. On the contrary, patients always place their great interest on their smile. Therefore, well-treated orthodontic cases should meet both requirements of good occlusion and attractive smile. Many factors affect the attractiveness of the smile. The visualization and quantification of the dynamic smile have been 1,2 described in details by Sarver and Ackerman. Lips also have a 3 profound effect on the attractiveness of the smile. The thickness of the lip, the phase and degree of smile play a predominant part of an 4 appealing smile. However, as they have already been described comprehensively, this article will focused on the dental and gingival tissue especially the ones that have the strong impact on the appealing smile. However, not all patients can have conventional orthodontic treatment. Not only due to the treatment cost, but also the difficult access to treatment may hinder them from conventional orthodontics. The duration of orthodontic treatment, health status of the patient and other factors have to be considered before the commencement of orthodontic treatment. Patients may not choose conventional orthodontic treatment because of these factors, therefore, they may opt for laminated veneers or other treatment options instead. In fact, short orthodontic treatment may help accomplishing the harmony of smile especially with the use of this commonsense formula. includes proportion and angulation of the teeth, gingival margin and zenith, contact and alignment. To remember this formula easily, they can be abbreviated into pagca. 1. Proportion of the teeth Proportion of the teeth can be described as length and width of the teeth. The thumb rule proposed by Gillen is that the 8 central incisor and canine should have an equal length. The lateral incisor length, however, should be eighty per cent of the length of central incisor and canine (Fig.1). Dentist tends to use golden proportion mentioned by Pythagoras to deal with the width proportion of the front teeth. The golden proportion illustrated an ideal apparent width of the teeth when they are viewed from the front. From this golden proportion, Levin proposed that the mathematical ratio of the width of the central incisor to lateral incisor and canine was 1.618: 1: Snow 10 simplified this ratio to 25:15:10 (Fig. 2). Next, the ideal proportion (width per height) of the maxillary central incisor 8 was reported to be eighty per cent. It also should be noted here that this ratio and proportion should be used as a guideline rather than a rigid rule. It should be used with an artistic sense of smiling curve and the dominance of the central incisors in mind. These two factors will be described later in this article Commonsense formula: lists of factors with strong impact on harmony of smile. Dental and gingival tissue poses a significant part in creating an attractive smile. Orthodontists use bracket as a tool to arrange this harmony of smile. Planned bracket position was described as the most important factor. It is essential to have a commonsense formula in mind to plan the bracket placement. This formula 14 Fig. 1 shows the length of the upper anterior teeth. The central incisor and canine s h o u l d h a v e a n e q u a l length(1=3). The lateral incisor length, however, should be eighty per cent of the length of central incisor and canine (2=80% of 1 or 3) Fig. 2 shows the ideal ratio of the mesio-distal width of the upper anterior teeth. The mathematical ratio of the width of the central incisor to lateral incisor and canine derived from golden proportion was 1.618: 1: The simplified ratio is 25:15:10.

16 While it is very common for dentist to change the proportion 3. Gingival margin and zenith of the teeth using laminate veneers, orthodontist tends to overlook this proportion because of the thinking of the Periodontal health must be established prior to planning for impossibility of adjustment. What is the reason for trying to bracket placement. Then the gingival margin and zenith will be work in case with compromised tooth proportion and not assessed. First, the level of the gingival margin affects achieving great smile? The tooth proportion could be changed influentially on the smile. The ideal level will be that the in so many ways, proximal stripping, laminate veneers, resin gingival margins of the central incisors are at the same level and composite veneers, crown lengthening procedure, laser match those of the canines. The gingival margin of the lateral gingivectomy. All these techniques could help correct this incisors should be placed slightly incisal comparing to the disproportionate. To achieve the well proportionate teeth and central incisors and the canines. (Fig. 5) This will exhibit great smile, it was recommended to design the smile and harmonized rise and fall of the gingival margin. Although the visualize the tooth proportion prior to the placement of bracket. 6,7 smile will look uniform when the gingival margins of all anterior teeth are placed at the same level, it is more acceptable 2. Angulation than placing the gingival margin of the lateral incisor more 14 apical than the central incisors. Next, gingival zenith is defined The angulation of the teeth was described by Andrews. The as the most apical point of the gingival tissue. It is located distal maxillary central incisor angulation was five degree. The to the long axis of the central incisor and the canine. However, angulation of lateral incisor and canine were eleven and two the gingival zenith of the lateral incisor is located at its mid degree respectively (Fig.3). These numbers maybe different labial point. (Fig. 6) upon the racial group, therefore, research on the specific racial 12,13 group maybe required. As mentioned before, the number should be followed only as a guideline rather than an inflexible rule. It should be used with an artistic sense of mimicking the contralateral tooth. Furthermore, the angulated tooth occupied space more than the non-angulated tooth. Therefore, this commonsense factor of straightening tooth provides more space to resolve crowding case. Likewise, tilting the tooth resolves the problem of spacing (Fig. 4). Fig. 5 shows the ideal level of the gingival margins. The gingival margins of the central incisors are at the same level and match those of canines. The gingival margin of the lateral incisors should be placed slightly incisal to central incisors and canine. Fig. 3. shows the angulation of the upper anterior teeth. The maxillary central incisor angulation was five degree. The angulation of lateral incisor and canine were eleven and two degree respectively. Fig. 4. Illustration of the effect of tilting the tooth. Teeth tiling resolves the problem of spacing. Likewise, s t r a i g h t e n i n g t o o t h provides more space to resolve crowding case. Fig. 6. Gingival zenith is located distal to the axis of the central incisor and canine. However, the gingival zenith of the lateral incisor is located at its mid labial point. 4. Contact The contact points of the maxillary teeth are relevant to the smiling curve which is the curvature parallel to the lower lip curvature representing pleasing smile. (Fig. 7) The contact between central incisors is the lowest. Then they are slightly 14 more apical for the lateral incisor and the canine respectively. 15

17 The more important factor may be the presence of the dark Case example I triangle. It is very apparent when it is located between triangular This case presents the intriguing point of proclined right shape teeth or absence of the adjacent tooth. Furthermore, maxillary incisor, periodontal disease and the cost and access to the Tarnow proposed the 5-mm rule which emphasized the dental school problem. This 18-year-old single Thai female was importance of the interproximal bone. It is stated that there is a transferred from general practitioner for correction of maxillary complete fill of the gingival embrasure when the distance from median diastema (Fig. 9, 10). Upper right central incisor had the the contact point to the interproximal osseous crest is five mm or periodontal pocket of 7 mm. (Fig. 11) There was slight anterior less. For every one mm above five mm, the chance of complete openbite. The right central incisor was two mm more proclined than 16 fill is progressively reduced by fifty per cent. Striping of the left central incisor (Fig. 12). She cannot afford the expense of teeth changes the triangular-shaped tooth to look more conventional orthodontic treatment including traveling expense to rectangular. The contact point then is changed to long contact the dental school. After the periodontal treatment finished, the patient was evaluated using pagca commonsense formula. First, or connector as it appears. As a result, the distance from the the proportion was evaluated. The length of the central incisor, contact point to the interproximal osseous crest is reduced. The lateral incisor and canine was 8.5:7:9 on the right hand side and dark triangular space appears smaller. Therefore, striping 8.5:7:8 on the left hand side. The ratio of the length versus width of reduces this dark triangular space. In short, it should be noted the lateral incisor and central incisor of this case was 82.4 per cent. here that tooth striping also provides more arch perimeter to Ideally, the length of the central incisor should be equal to the resolve crowding. 17 length of canine. Ideal proportion for the length of lateral incisor should be eighty per cent comparing to central incisor and canine. Although the ratio was not precisely correct, the mimicking of the contralateral teeth thumb rule was applied. Supposedly, it should be able to achieve compromised harmony of smile. The width of the front teeth was then considered using golden percentage. The width of the teeth was demonstrated in Table 1. Fig. 7. The contact points of the maxillary teeth are relevant to the smiling curve. 5. Alignment As mentioned, tooth striping reduces space required for alignment of teeth. Proclination of the maxillary teeth also increase arch perimeter, thus make alignment of crooked teeth 18,19 possible (Fig.8 ). Optimal overjet and overbite also can be 19 established using this technique. These two techniques combined facilitate alignment of the anterior teeth with the least change of the posterior occlusion. Fig. 9. Pre-operative extra-oral photographs. Fig. 10. Pre-operative smile. Fig. 8. Retroclination of the maxillary teeth decreases the arch perimeter. The result is that the spacing teeth (teeth in grey colour) are resolved (dotted teeth). On the other hand, proclination of the maxillary teeth increases arch perimeter, thus resolving crowded teeth. Fig. 11. Pre-operative radiograph. There was vertical bone loss between central incisors. Fig. 12. The left central incisor was three mm more proclined than right central incisor. 16

18 Table 1. shows the ratio of the mesio-distal width of the anterior teeth calculated for pre-operative width, laminated veneers and laminated veneers after orthodontic treatment. The ideal golden percentage is also showed. Golden percentage Pre-operative width Laminated veneers Canine Right Lateral incisor Central incisor Central incisor Left Lateral incisor Canine should be able to camouflage this dark triangular space. As shown postoperatively, the long contact was used on the veneers to help hiding this gingival margin discrepancy. Last factor, the alignment of the teeth was reviewed. The upper right central incisor was more proclined than the contralateral central incisor. Prosthodontist maybe reluctant to place laminated veneers onto the teeth with facio-palatal malalignment. This will cause less than ideal contour on the teeth with compromised periodontal health. This factor also supports the orthodontic alignment of the anterior teeth prior to veneers. Finally the plan was formulated. The central incisors'roots were tipped slightly distally. Then they were retracted slightly to reduce the openbite and mesio- distal space for veneers. It was done using slot bracket on four anterior teeth and NiTi archwire. (fig. 13) Resin composite veneers were then placed (fig. 14), followed by the upper clear retainer. Immediate post operative result is showed in figure 15. The patient was very pleased with the harmonized smile and it could be maintained for more than five years (fig. 16). Orthodontics and veneers To easily evaluate the percentage of tooth width, the width of the lateral incisor was adjusted to approximately the stable value of 15 per cent. It is clearly confirmed that without orthodontic treatment the width of the central incisor would be too wide. Since there was slight openbite and spacing anteriorly in this case, the central incisor could be placed more retroclined. This could be done to achieve the width of the central incisor of twenty-three per cent which is more acceptable. Second the angulation of the teeth was evaluated. Radiographically, the two central incisors appeared parallel. However, they did not look symmetrical clinically. The central incisor roots looked mesially inclined. It would be difficult to make them look symmetrical even with the use of laminated veneers. Hence, the aim of aligning these two teeth was to set them look slightly more parallel. Third, the gingival margin and zenith were mentioned. Although there was moderate periodontitis, after periodontal treatment was finished, there was no gingival recession on the labial side of the teeth. Post periodontal treatment, the patient maintained excellent oral health. The gingival margin was in harmony. The gingival margin of the lateral incisor was slightly incisal to central incisors and canine. Unlike gingival margin, the gingival zenith of this case, however, was compromised. The gingival zenith of the central incisor was too far mesial. The gingival zenith of the lateral incisors were slightly too far distal. The gingival zeniths of canines were in the ideal position. Therefore, changing the zenith of the central and lateral incisors was planned. Fourth, the contact was considered. As mentioned before, the periodontal health of this case was less than ideal. The gingival margin on the mesial side of the right central incisor was not equal to the mesial side of the left incisor. The contact of the veneer Fig. 13. Intra-operative photograph. Fig. 14. Post-operative photograph. Fig. 15. Post retention with clear retainer. 17

19 Pre-op photo Immediate post-op photo Five-year post-op photo Fig. 17. Pre-operative extra oral photographs. Pre-op photo Immediate post-op photo Five-year post-op photo Fig. 18 Pre-operative smile. Note the angulation of the right lateral incisor. Fig 16. Pre- and post-operative photographs. Please note the long contact to reduce the dark triangular space. Case Example II This case presents the option that only braces may close the diastema without restoration at all. The interesting point is that only three months of well-planned treatment, she achieved the great smile with only four braces and a couple of pieces of archwire. This 33-year-old single Thai female was transferred from general practitioner for correction of maxillary median diastema. There was no apparent periodontitis (fig. 17). The overjet and overbite was within normal limit. The right lateral incisor, however, was distally inclined (fig. 18). She could not afford the expense of conventional orthodontic treatment. After the oral prophylaxis finished, the patient was quickly evaluated using pagca commonsense formular. As it was used so many times, it was clear that the main factor that cause unpleasing smile was not pca. Only the ag which stands for angulation, gingival margin and zenith caused the problem. There was spacing between two central incisors. The angulation of the central incisors and the left lateral incisor were straight. However, the angulation of the right lateral incisor was distally inclined. This distally inclined right lateral incisor caused the asymmetrical appearance of the left and right lateral incisor. Moreover, the gingival margin and zenith were less than ideal. The aim of the treatment was to change the angulation of these four incisors to occupy the whole space. Brackets were then placed with slightly distal inclination on all four incisors inch Nickel-Titanium archwire was tied to the bracket followed by 0.016x0.022 stainless steel archwire with artistic bend (Fig. 19). The harmony of smile was then achieved without any restoration (Fig. 20, 22). The clear plastic retainer was then delivered (Fig. 21). Fig. 19. Intra-operative photograph Discussion Fig. 21. Clear retainer. Fig. 20. Post-operative photograph Using this commonsense formula for bracket placement facilitates treatment outcome. Therefore, it is best to have the list of all these factors in mind prior to the start of the treatment. Experienced orthodontists may learn this fact after years of practicing. However, clinicians may sometimes make mistake 18

20 during bracket placement procedure. Reevaluation of the case during treatment will serve as the margin of safety for any mistake. At this stage, digital photograph or video become very obtainable. Therefore, it will be a minimum effort for clinicians to reevaluate the smile from the photograph that was taken by the photographer. It also should be noted here that the perception of the patient is the key to success. Occupation, gender and social status of the patient also have a strong effect on the perception of the smile. Orthodontists could be very sensitive to even minor error. In some cases, only mimicking the contralateral tooth satisfies the patient. This mimicking is more crucial on the central incisors. It becomes less critical the further the teeth are away from the midline. This effect is called the dominance of the central incisors. Therefore, it will not be unwise to evaluate the patient perception and vary the planned bracket position accordingly. patients cannot have complete orthodontic treatment, however, they may need some minor adjustment for harmony of smile. After careful evaluation of the occlusion, minor tooth movement using commonsense formula pagca can help attaining this goal. Digital photographic technology greatly facilitates this technique. The balance of the perception of the patient, artistic sense and rigid mathematic ratio will dramatically create a harmony of smile with only little effort. Acknowledgement The author would like to thank Doctor Ladda Wongwerawinich for the general dental treatment of the case example I. Special thanks were made to Mr. Ket Charearnlarp for the help with the technical advice of the drawing of the pictures. References 1. Sarver DM, Ackerman MB. Dynamic smile visualization and quantification: part 1. Evolution of the concept and dynamic records for smile capture. Am J Orthod Dentofacial Orthop. 2003;124(1): Sarver DM, Ackerman MB. Dynamic smile visualization and quantification: Part 2. Smile analysis and treatment strategies. Am J Orthod Dentofacial Orthop. 2003;124(2): Scott CR, Goonewardene MS, Murray K. Influence of lips on the perception of malocclusion. Am J Orthod Dentofacial Orthop. 2006;130(2): Tarantili VV, Halazonetis DJ, Spyropoulos MN. The spontaneous smile in dynamic motion. Am J Orthod Dentofacial Orthop. 2005;128(1): Sarver D, Yanosky M. Combined orthodontic, orthognathic, and plastic surgical treatment of an adult Class II malocclusion. J Clin Orthod. 2005;39(4): Sarver DM, Yanosky M. Principles of cosmetic dentistry in orthodontics: part 2. Soft tissue laser technology and cosmetic gingival contouring. Am J Orthod Dentofacial Orthop. 2005;127(1): Sarver DM, Yanosky M. Principles of cosmetic dentistry in orthodontics: Part 3. Laser treatments for tooth eruption and soft tissue problems. Am J Orthod Dentofacial Orthop. 2005;127(2): Gillen RJ, Schwartz RS, Hilton TJ, Evans DB. An analysis of selected normative tooth proportions. Int J Prosthodont. 1994;7(5): Levin EI. Dental esthetics and the golden proportion. J Fig. 22. Pre- and Post-operative Photographs. Prosthet Dent. 1978;40(3): Snow SR. Esthetic smile analysis of maxillary anterior tooth width: the golden percentage. J Esthet Dent. 1999;11(4): Andrews LF. The six keys to normal occlusion. Am J Conclusion Orthod.1972; 62: Currim S, Wadkar PV. Objective assessment of occlusal and Orthodontists mainly aim the treatment goal at the perfect coronal characteristics of untreated normals: a measurement occlusion, while patients concentrate more on aesthetics. Some study. Am J Orthod Dentofacial Orthop. 2004;125(5):