Chapter 54 Practical Plastic Surgery, edited by Zol B. Kryger and Mark Sisco. ©2007 Landes Bioscience. Cephalometrics Matthew Jacobsen and Jeffrey A. Hammoudeh Introduction The analysis of a patient with a skeletal deformity can be complex. However, there are many diagnostic tools available that help the surgeon understand the etiol- ogy of the deformity, including the history and physical, radiographic exams, videocephalometric analysis and cast dental models. The integration of this infor- mation provides the appropriate diagnosis and guides treatment. The goal of this chapter is to provide the clinician with the basic working principles for detecting and diagnosing maxillofacial deformities. Clinical Exam—Dental Classification Terminology: •Open bite—the tips of the incisors are not directly opposed • Overbite—the vertical distance between the tips of the incisors • Overjet—the horizontal distance between the tips of the incisors • Neutral occlusion (Class I)—the maxillary first molar mesiobuccal cusp fits in the buccal groove of the mandibular first molar • Distal occlusion (Class II)—the maxillary first molar mesiobuccal cusp is ante- rior to the buccal groove of the mandibular first molar • Mesial occlusion (Class III)—the maxillary first molar mesiobuccal cusp is posterior to the buccal groove of the mandibular first molar The frontal smiling exam documents symmetry of the smile as well as the amount of maxillary and mandibular dentition and gingival exposure. The normal amount of exposed gingiva during smiling is 1-2 mm. Particular attention should be paid to the amount of maxillary tooth show from central incisor to canines. In addition, during the intraoral exam the clinician should look for an anterior or posterior open bite. It is important to determine the maxillary and mandibular midpoints in order to understand if the maxilla and mandible are coincident with the facial mid- line or if there is a deviation of one or both. Finally the intraoral exam is used to assess for the presence of overjet, overbite and malocclusion. Facial Relationships Aside from the standard history and physical, the clinical exam incorporates subjective numerical data. With the patient seated at eye level across from you, evaluate the face into its proportions of facial thirds. Facial proportions are be con- sidered within the context of the following normal relationships: • The intercanthal width is roughly equal to the alar base width. • The lower eyelid rests at or above the most inferior position of the iris. Measure any scleral show as it may be a sign of exophthalmos or infraorbital hypoplasia. 54 328 Practical Plastic Surgery • The width of the nasal dorsum is half the intercanthal width. • Facial midline, nasal tip, maxillary and mandibular midlines, and chin point are in line. • Upper face height (glabella to subnasale) should be equal to lower face height (subnasale to menton). Inspect for symmetry and size of the forehead, orbits, eyes, ears and nose. Use- ful measurements include: • Interpupillary width: normal is 65 mm • Intercanthal width: normal is 32 mm for whites and 35 mm for African Ameri- cans • Upper lip length: normal is 22 mm for males and 20 mm for females. Measured from subnasale to upper lip stomion. • Upper tooth to lip relationship: 2.5 mm of incisal edge lips the lips relaxed • Lower lip length: normal is 42 mm for males, 38 mm for females. Measured from lower lip stomion to menton. At the end of the physical exam, take high quality digital photographs. These pho- tos will be crucial to videocephalometric predictions, correlation with model surgery, and will be referred to intraoperatively. The following photos are recommended: • Frontal photograph relaxed • Frontal photograph smiling • Lateral profile—right and left • 45˚ oblique • Intraoral—central, right, left The fabrication of dental casts aids in diagnosis as well as treatment. For ex- ample, in orthognathic surgery it is essential to fabricate surgical splints. The casts must be properly mounted using the facebow, bite record and articulator. The orthognathic workup and cephalometric analysis are important since they determine many of the surgical movements. A key point to an accurate workup is the careful positioning of the mandible in centric relation rather than in centric occlusion during the bite registration. Centric relation denotes position of man- dible where the condyles are in the most superior, posterior position in the man- dibular fossa. Centric occlusion is the position with maximal intercuspation of the teeth. During surgery, the mandible is positioned in centric relation as this depicts the skeletal defect and allows for a reproducible anatomic position. Radiographic Analysis After the clinical exam is completed, radiographic analysis helps to further define the nature of the patient’s maxillofacial deformity. The Panorex, lateral cephalogram and AP cephalogram are used. The Panorex is inspected for pa- thology of the sinus, joints, mandible, maxilla and dentition. Examine the Panorex closely for condylar morphology and position. The Ramus Condyle Unit is measured to determine if there are any asymmetries in condylar growth. This may be indicative of conditions such as idiopathic condylar resorption or condylar hyperplasia. The lateral and AP cephalograms are the two principle radiographs of othognathic surgery and cephalometric analysis. Classical cepha- lometric analysis required tracing the cephalometric film by hand. This allowed for identification of the hard and soft tissue landmarks used in the cephalomet- ric analysis. Digital radiographs and computer cephalometric analysis are replac- ing traditional radiographs and hand tracings. Using a computerized tracing 54 329 Cephalometrics program, the surgeon selects several landmarks on the digitized lateral cephalogram. The computer then produces the cephalometric measurements and the digital tracing. The relationship between the cranial base, nasomaxillary complex, mandible and maxillomandibular dentition is determined by the resulting angular and lin- ear measurements. Notably, the surgeon may measure the distance from sella to posterior nasal spine (PNS). This value determines the position of the posterior maxilla in relation to the cranial base. The normal value is between 45-50 mm. Cephalometric Analysis The cephalometric analysis is a valuable tool that will assist the clinician with the diagnosis of a facial deformity. The diagnosis and treatment plan are deter- mined during the clinical and cephalometric analysis. There are a variety of cepha- lometric analyses in clinical practice; the Singer and Harvard methods are most commonly used. Normal values for cephalometric measurements in adults are listed in Table 54.1. Important cephalometric measurements include the following: 1. Porion: midpoint of upper contour of the external auditory canal 2. Sella: midpoint of the sella turcica 3. Orbitale: most inferior point along the bony orbit 4. Pterygomaxillary fissure: most superior posterior point of the pterygomaxillary fissure 5. Nasion: most anterior point of the frontonasal suture 6. Basion: Most inferior anterior point of the foramen magnum 7. Anterior nasal spine (ANS): most anterior point of the anterior nasal spine 8. Posterior nasal spine (PNS): most posterior point of the anterior nasal spine 9. A point: most posterior point along the bony premaxilla between ANS and maxillary incisor Table 54.1. Cephalometric measurements for adults (in mm) Parameter Male Female Maxillary length 114 4) 105 (3) Mandibular length 127 (5) 119 (4) Total facial height 137 (8) 123 (5) Upper face height 80 (6) 55 (2) Lower face height 80 (6) 69 (5) Ethmoid point—PNS 55 (4) 50 (3) Sella—PNS 56 (4) 51 (3) Posterior face height 88 (6) 79 (4) Palatal plane—Menton 76 (6) 67 (4) Palatal plane—upper molar 28 (3) 25 (2) Palatal plane—upper incisor 33 (3) 30 (3) PNS—ANS 62 (4) 57 (4) Mandibular plane—lower incisor 49 (3) 42 (3) Manibular plane—lower molar 38 (3) 33 (3) 54 330 Practical Plastic Surgery 10.B point: most posterior point along the bony contour of the mandible between mandibular incisor and pogonion 11.Pogonion: most anterior point along the contour of the bony chin 12.Menton: most inferior point along the mandibular symphysis 13.Gnathion: point along bony chin between menton and pogonion 14.Gonion: angle of the mandible at the intersection of the tangents drawn from the posterior ramus border and the lower ramus 15.Articulare: point of intersection between the cranial base and posterior ramus 16.Condylion: most superior posterior point of the bony condyle Important cephalometric planes and angles include the following: 1. Sella-Nasion-A point: SNA 2. Sella-Nasion-B point: SNB 3. A point-Nasion-B point: ANB 4. Frankfort horizontal (FH) plane: Pogonion—Orbitale 5. Palatal plane: ANS-PNS 6. Occlusal plane: plane from mesial cusp of maxillary molar through point bi- secting overbite 7. Mandibular plane: tangent along lower border of mandible 8. Gonial angle: Articulare-Gonion-Menton SNA and SNB provide an assessment of the maxillary and mandibular relation- ship to the cranial base. However, in order to utilize SN as the normal inclination of the anterior cranial base, the surgeon must first normalize the actual SN position to the normal SN-FH of 6 degrees. In most patients, the sella turcica is normally posi- tioned and thus the sella to Frankfort angle is normal. However, in patients with craniofacial deformities, congenital syndromes, or sequences, it is imperative to iden- tify the relationship of sella-to-FH. Altering the normal position of sella will, by default, alter the SNA and SNB. In order to assess the true SNA/SNB one must determine the SN-FH correction. 1. First measure the SN-Frankfurt angle (normal is 6˚) 2. If the SN-F angle is abnormally acute due to a shallow SN plane, the mea- sured SNA and SNB will be too obtuse. Therefore, we must subtract the difference ([SN-FH actual -SN-FH normal ]) to generate the “corrected” SNA and SNB. 3. If the SN-F angle is abnormally obtuse due to a steep SN plane, the measured SNA and SNB will be too acute. Therefore, one must add the difference ([SN-FH actual -SN-FH normal ]) to generate the “corrected” SNA and SNB. PA Cephalogram The PA cephalogram illustrates transverse and vertical skeletal relationships and evaluates facial symmetry. The first step in analyzing the PA film is to analyze the transverse dimension using a J point analysis. A horizontal measurement is made from the lateral aspects of the maxilla at the level of the pyriform rims. Similarly, a horizontal measurement is made from antegonial notch form right to left. The dif- ference between these two values is used to identify an excessively narrow maxilla or enlarged mandible. The normal J point value is between 20 and 23 mm. Next, the PA cephalogram is drawn on tracing paper. Horizontal lines are drawn at the in- fraorbital rim, pyriform rim, occlusal plane and gonial angle. These marks are com- pared to a vertical midline mark in order to determine symmetry and cant of the orbits, zygomas, maxilla and mandible. 54 331 Cephalometrics Figure 54.1. Common cephalometric points and their relationships. 54 332 Practical Plastic Surgery Maxillary Abnormalities The most common problems associated with the maxilla include maxillary sagittal hypo/hyperplasia, maxillary vertical hypo/hyperplasia and maxillary transverse hypo/hyperplasia. When evaluating a patient for maxillary surgery the surgeon must evaluate the following: 1. Vertical position of the maxilla 2. Sagittal position of the maxilla 3. Transverse width of the maxilla Useful measurements include: PNS-Sella, maxillary tooth show, occlusal plane angle, J point analysis, nasolabial angle, SNA and ANB. The LeFort I osteotomy is used to correct deformities of the maxilla in the vertical, sagittal and transverse planes. It is commonly employed to treat sagittal hypoplasia (small SNA), vertical maxillary excess (excess gingival show) and anterior open bite (large PNS-Sella). Mandibular Abnormalities Common problems associated with the mandible include mandibular sagittal hypoplasia and mandibular sagittal hyperplasia. Cephalometric measurements used to evaluate the mandibular position include SNB, ANB, gonial angle and man- dibular length. SNB determines the relative position of the mandible to the cranial base, and ANB illustrates the position of the mandible as related to the maxilla. Large values of mandibular length are associated with mandibular prognathism. The patient with a long lower face height or open bite will often have a large gonial angle. The Class III patient often has a diagnosis of mandibular sagittal hyperplasia. Most often, the patient has a prominent lower jaw and chin and a long lower face height. The Class II patient typically has a diagnosis of mandibular sagittal hypopla- sia. Most often, the patient has a small mandible, retrusive chin and obtuse cervicomandibular angle. Surgical treatment of the mandible for mandibular prog- nathism includes bilateral sagittal split osteotomy (BSSO) and vertical ramus osteotomy (VRO). Cephalometric Analysis and Predictions Computerized cephalometric analysis and predictions have become the stan- dard in orthognathic surgery. Many popular software packages allow for incorpo- ration and analysis of radiographic images. They enable the clinician to pinpoint angles on a digitized AP and lateral cephalogram and generate cephalometric cal- culations. These calculations can be adjusted for gender, race and age. Following cephalometric analysis, the software generates a cephalometric tracing based on the points and angles identified by the physician. The clinical photograph is over- laid and incorporated into the digitized radiograph. The digitized cephalometric data is used to generate diagnosis and treatment based on the measurements. Overall, the computerized cephalometric software program is a good tool in the rapid diagnosis of dentofacial deformity. It allows for the interface between digi- tized radiographs, cephalometric measurements and cephalometric predictions. Ultimately, the goal in cephalometric imaging is the incorporation of 3-D imag- ing and predictions. Model Surgery As discussed previously, othognathic surgery consists of mandibular surgery, max- illary surgery and double jaw procedures. Surgeons use model surgery to aid in 54 333 Cephalometrics planning of the operation. Model surgery facilitates precise surgical movements. In general, the patient presents for diagnostic evaluation when the skeletal malforma- tion is first identified. At that time, diagnostic records, radiographs, images and dental models are fabricated. This process is repeated immediately before the opera- tion. Appropriate images, measurements, radiographs and models are generated prior to the operation. Specifically, dental casts are fabricated from dental impression and stone. A face-bow record of the patients Frankfort horizontal plane to occlusal plane is generated. The dental casts are articulated using a bite record in centric relation and these are mounted on an anatomic semiadjustable articulator. Reproducible vertical reference lines are placed at the midline, canine tip, mesiobuccal cusp of the first molar and posterior retromolar region. Horizontal reference lines are placed at 10 and 20 mm from the articulator mounting plate. The cast is separated from the mounting ring at 15 mm, centered between the two horizontal reference lines. Next, model surgery is performed on the mandible, maxilla, or both by position- ing the maxillary and mandibular arches into an ideal occlusal relationship. The horizontal and vertical reference lines keep the models in the appropriate vertical, anteroposterior and transverse relationship. A final surgical splint is fabricated using methyl methylacrylate resin. In the case of double jaw surgery, the maxilla is first positioned in the predicted horizontal and vertical position. A splint is fabricated using methylmethacrylate that preserves this “intermediate” maxillomandibular re- lationship. Next, the mandibular cast is moved into an ideal occlusal relationship with the maxilla, creating the final splint. Pearls and Pitfalls An inexperienced surgeon who takes a bite registration in centric occlusion rather than centric relation will end up with inaccurately mounted modes, inac- curate splints, and eventually a nonreproducible, unstable result with a malocclu- sion intraoperatively. The SN-FH correction must be taken into consideration in order to have an accurate cephalometric prediction and treatment plan. Most patients have a normal SN-FH and thus do not require any correction factors; however children with cran- iofacial anomalies often require close analysis of the corrected FH, otherwise the cephalometric analysis will not be accurate. Suggested Reading 1. Ash M. Wheelers Dental Anatomy, Physiology and Occlusion. Philadelphia: Saunders, 2000. 2. Betts N, Turvey T. Orthognathic surgery. In: Fonseca R, ed. Oral and Maxillofacial Surgery. Philadelphia: Saunders, 2000. 3. Ferraro JW. Cephalometry and cephalometric analysis. In: Ferraro JW, ed. Fundamen- tals of Maxillofacial Surgery. New York: Springer, 1997. 4. Kaban LB, Troulis MJ. Pediatric Oral and Maxillofacial Surgery. Philadelphia: Saunders, 2004. 5. Peterson LJ, Ellis E, Hupp JR et al. Contemporary oral and maxillofacial surgery. St. Louis: Mosby, 1998. 6. Profitt WR, Thomas PM, Camilla-Tulloch JF. Contemporary orthodontics. St Louis, Mosby: 1986. 7. Proffit WR, White RP, Sarver DM. Contemporary treatment of dentofacial deformity. St. Louis. Mosby: 2002. Chapter 55 Practical Plastic Surgery, edited by Zol B. Kryger and Mark Sisco. ©2007 Landes Bioscience. Craniofacial Syndromes and Craniosynostosis Zol B. Kryger and Pravin K. Patel Craniosynostosis Introduction Craniosynostosis is the premature fusion of the sutures of the skull. Although the cause of this condition is not known, TGF-beta has been strongly implicated as playing a major role. Craniosynostosis can occur as an isolated event or in the con- text of a craniofacial syndrome. The sporadic nonsyndromic cases are more com- mon (incidence of 1 in 2000 live births) than the syndromic cases, many of which are related to defects in the FGF receptor (FGFR). Virchow’s law can help predict the developing skull shape. It states that growth is restricted perpendicular to the fused suture, and compensatory growth occurs parallel to the affected sutures. Affected Suture One or more sutures can be affected in craniosynostosis. Sagittal synostosis is the most common form, accounting for over half of all cases. Table 55.1 summarizes the various involved sutures and the characteristic appearance of the skull: Deformational (Nonsynostotic) Plagiocephaly This condition is more common than posterior plagiocephaly due to cranio- synostosis with an incidence of 1 in 300 live births. The incidence of this condition increased significantly after recommendations by pediatricians that infants sleep supine in order to decrease the risk of SIDS. Deformational plagiocephaly occurs as a result of supine positioning during the first few weeks of life. Features that help distinguish it from synostotic plagiocephaly (lambdoid synostosis) can be seen in Table 55.2. Table 55.1. Various involved sutures and characteristic appear- ances of the skull Involved Suture Skull Appearance Unicoronal Anterior plagiocephaly Bicoronal Turribrachycephaly (bitemporal widening) Sagittal Scaphocephaly (biparietal narrowing) Metopic Trigonocephaly (triangular forehead) Lambdoid Posterior plagiocephaly (flat posterior skull) Coronal, lambdoid, metopic Kleeblattschadel (clover leaf skull) 55 335 Craniofacial Syndromes and Craniosynostosis Associated Symptoms Elevated intracranial pressure (ICP)—occurs in 13% of single suture synostosis and 42 % of multiple suture synostoses. Strabismus—seen most often in unilateral, coronal synostosis. It is due to paresis of the superior oblique muscle. Torticollis—seen in about 15% of cases of anterior plagiocephaly, usually on the unaffected side. Cognitive deficits—seen most commonly with metopic synostosis. Treatment The goal of treatment is foremost to allow adequate space for the brain to grow. Of lesser importance is the creation of an aesthetically normal skull and forehead. Molding (orthotic cranioplasty) Molding of the skull, or orthotic cranioplasty, is done with a helmet worn up to 23 hours a day for 2-4 months. It should begin around the age of 6 months and always before the age of 14 months. It is the recommended treatment for deformational plagiocephaly and can also be used as an adjunct to surgery. Surgery Since the most rapid phase of skull growth occurs within the first year of life (Fig 55.1), early treatment is required. Surgical intervention is most commonly performed between the ages of 3 to 12 months of age. There is some evidence that earlier intervention results in fewer learning disabilities and emotional problems in later years. However, these findings are disputed by those who believe that operating on infants with craniosynostosis will not have an effect on their future cognitive abili- ties. Regardless of the timing, surgical treatment must be tailored to the individual’s deformed structures. Unilateral coronal synostosis is managed with unilateral or bilateral fronto-or- bital advancement. Bilateral coronal synostosis is managed with bilateral fronto- orbital advancement. If there is evidence of brachycephaly, total calvarial reconstruction may be required. Sagittal synostosis is treated with strip craniecto- mies and partial-wedge osteotomies. If biparietal expansion is required, anterior and posterior parietal wedges may be required. Lambdoid synostosis is managed with excision of the lambdoid suture. Metopic synsotosis is treated with removal of the supraorbital bar, corticotomy and correction of the midline angle with bone grafts Table 55.2. Comparison of features between synostotic and deformational plagiocephaly Synostotic Deformational Feature Plagiocephaly Plagiocephaly Sutures Fused Patent Eyebrow Elevated on affected side Eyebrow lower on affected side Ear Rotated anterosuperior Rotated posteroinferior Nose Deviated to opposite side Deviated to affected side Chin Deviated to opposite side Deviated to affected side Cheek Forward on affected side Flattened on affected side Torticollis Contralateral side Ipsilateral side 55 336 Practical Plastic Surgery or miniplates. Kleeblattschadel is treated after life-threatening conditions are ad- dressed (e.g., hydrocephalus, airway obstruction) with anterior calveriectomy and fronto-orbital advancement. Excess constricting bands of bone are removed. Complications As might be expected from the magnitude of the procedures, the complications can be devastating. Early complications specific to these procedures include: sagittal sinus tears with venous infarction, subdural hematoma, cerebral edema, excess vaso- pressin production (SIADH), nerve injuries, injury to the orbits, infections, elevated ICP and dural leaks. Late complications include: incomplete advancement, pal- pable hardware, alopecia, asymmetry, orbital deformities, pseudomeningocele and increased ICP. Craniofacial Syndromes Many craniofacial syndromes have been described in the literature. However, with a few exceptions, these are rare syndromes seen primarily in specialized centers. A discussion of the more commonly encountered craniofacial syndromes follows with an emphasis on the similarities and differences between them. Apert Syndrome (Acrocephalosyndactyly) • Autosomal dominant • Bicoronal synostosis • Hypertelorism or exorbitism • Strabismus • Maxillary hypoplasia • Acne and coarse skin Figure 55.1. The growth curve of the skull. [...]... Smith Plastic Surgery 5th ed Philadelphia: Lippincott-Raven Publishers, 1997:24 5-2 53 3 Cutting CB Primary bilateral cleft lip and nose repair Grabb and Smith Plastic Surgery 5th ed Philadelphia: Lippincott-Raven Publishers, 1997:25 5-2 62 4 Grayson BH, Santiago PE Presurgical orthopedics for cleft lip and palate Grabb and Smith Plastic Surgery 5th ed Philadelphia: Lippincott-Raven Publishers, 1997:23 7-2 44... 1 969 ; 43:373 6 Hackney FL Plastic surgery of the ear Selected readings in plastic surgery 2001; 9( 16) :9 7 Nagata S Modification of the stages in total reconstruction of the auricle: Part I-IV Grafting the three-dimensional costal cartilage framework for lobule type microtia Plast Reconstr Surg 1994; 93:221 8 Tanzer RC Congenital deformities of the auricle In: Coverse JM, ed Reconstructive Plastic Surgery. .. Surg 19 96; 98: 765 5 Kapp-Simon KA Mental development and learning disorders in children with single suture craniosynostosis Cleft Palate Craniofac J 1998; 35:197 6 Losken HW, Pollack IF Craniosynostosis In: Bentz ML, ed Pediatric Plastic Surgery 1st ed Stamford: Appleton and Lange, 1998 7 Marchac D, Renier D, Broumand S Timing of treatment for craniosynostosis and faciocraniosynostosis: A 20-year experience... roll-vermilion-mucosal flaps are apposed to create Cupid’s bow and tubercle complex Postoperative Considerations For the child who is breastfed, the author encourages uninterrupted breastfeeding after surgery Some centers will allow bottle-fed children to resume feedings immediately following surgery with the same crosscut nipple used before surgery, while others have the child use a soft catheter-tip... of the vermilion-cutaneous junction and inset of the vermilion mucocutaneous triangular flap, the lip may appear to be vertically short One solution is to inset a small, 2- to 3-mm triangular flap into the medial lip just 58 above the vermilion Suggested Reading 1 Afifi GY, Hardesty RA Bilateral cleft lip Plastic Surgery, Indications, Operations and Outcomes St Louis: Mosby, 2000: 76 9-7 97 2 Byrd HS Unilateral... percutaneous, bone-anchored hearing aid is used At Table 57.1 Classification of microtia Grade I II III IV V Description Anotia Complete hypoplasia (± atresia of the external auditory canal) Middle third auricular hypoplasia Superior third auricular hypoplasia Prominent ears Practical Plastic Surgery, edited by Zol B Kryger and Mark Sisco ©2007 Landes Bioscience 344 Practical Plastic Surgery about the... 51:578 6 LaRossa D Unilateral cleft lip repair Plastic Surgery, Indications, Operations and Outcomes St Louis: Mosby, 2000:75 5-7 67 7 LaRossa D, Donath G Primary nasoplasty in unilateral and bilateral cleft lip nasal deformity Clin Plast Surg 1993; 29(4):781 8 Mulliken JB Primary repair of the bilateral cleft lip and nasal deformity In: Georgiade GS, ed Plastic, Maxillofacial and Reconstructive Surgery. .. occlusion plane Absent condyle, part of the ramus Absent condyle, part of the ramus, glenoid fossa, zygomatic arch Absent condyle, part of the ramus, glenoid fossa, zygomatic arch, hypoplastic zygoma, lateral orbital wall displaced Absent condyle, part of the ramus, glenoid fossa, zygomatic arch, inferior orbit displacement with loss of orbital volume Pearls and Pitfalls 56 • Roughly 25% of patients with... in Caucasians and 0.41:1000 in African-Americans Isolated clefts of the lip occur in 21% of the affected population, while 46% of cases involve clefts of the lip and palate and 33% are isolated clefts of the palate Clefts of the lip are more commonly left sided and unilateral (6: 3: 1 left: right: bilateral) and show a male predominance 350 Practical Plastic Surgery Clinical Findings Unilateral clefts... creating greater projection Creating the framework from the segments labeled 1 (main body), 2 (helical rim) and 3 (tragus) The pieces of cartilage are sutured together using 4-0 and 5-0 clear nylon sutures (below) 3 46 Practical Plastic Surgery cartilage are carefully carved into the desired shapes with a scalpel and chisels In adults, the rib cartilages are often fused and the entire framework must be sculpted . face height 80 (6) 55 (2) Lower face height 80 (6) 69 (5) Ethmoid point—PNS 55 (4) 50 (3) Sella—PNS 56 (4) 51 (3) Posterior face height 88 (6) 79 (4) Palatal plane—Menton 76 (6) 67 (4) Palatal. othognathic surgery consists of mandibular surgery, max- illary surgery and double jaw procedures. Surgeons use model surgery to aid in 54 333 Cephalometrics planning of the operation. Model surgery. Contralateral side Ipsilateral side 55 3 36 Practical Plastic Surgery or miniplates. Kleeblattschadel is treated after life-threatening conditions are ad- dressed (e.g., hydrocephalus, airway obstruction)